130 research outputs found
Solar-grade silicon prepared by carbothermic reduction of silica
An advanced carbothermic reduction (ACR) process was developed to produce solar grade (SC) silicon from high purity silica and carbon. Preparation of starting materials and operation of the arc furnace to product high purity silicon is described. Solar cells prepared from single crystal SG-Si had efficiencies of up to 12.3% practically identical to cells made from electronic grade silicon. The ACR process is not in the pilot stage for further evaluation
Spatial Distribution of Macrophages During Callus Formation and Maturation Reveals Close Crosstalk Between Macrophages and Newly Forming Vessels
Macrophages are essential players in the process of fracture healing, acting by remodeling of the extracellular matrix and enabling vascularization. Whilst activated macrophages of M1-like phenotype are present in the initial pro-inflammatory phase of hours to days of fracture healing, an anti-inflammatory M2-like macrophage phenotype is supposed to be crucial for the induction of downstream cascades of healing, especially the initiation of vascularization. In a mouse-osteotomy model, we provide a comprehensive characterization of vessel (CD31+, Emcn+) and macrophage phenotypes (F4/80, CD206, CD80, Mac-2) during the process of fracture healing. To this end, we phenotype the phases of vascular regeneration-the expansion phase (d1-d7 after injury) and the remodeling phase of the endothelial network, until tissue integrity is restored (d14-d21 after injury). Vessels which appear during the bone formation process resemble type H endothelium (CD31hiEmcnhi), and are closely connected to osteoprogenitors (Runx2+, Osx+) and F4/80+ macrophages. M1-like macrophages are present in the initial phase of vascularization until day 3 post osteotomy, but they are rare during later regeneration phases. M2-like macrophages localize mainly extramedullary, and CD206+ macrophages are found to express Mac-2+ during the expansion phase. VEGFA expression is initiated by CD80+ cells, including F4/80+ macrophages, until day 3, while subsequently osteoblasts and chondrocytes are main contributors to VEGFA production at the fracture site. Using Longitudinal Intravital Microendoscopy of the Bone (LIMB) we observe changes in the motility and organization of CX3CR1+ cells, which infiltrate the injury site after an osteotomy. A transient accumulation, resulting in spatial polarization of both, endothelial cells and macrophages, in regions distal to the fracture site, is evident. Immunofluorescence histology followed by histocytometric analysis reveals that F4/80+CX3CR1+ myeloid cells precede vascularization
Utilization of Electrohydrodynamic Cavitation in Primary Sludge Conditioning
This paper presents a brief characterization of the method of electrochemical conditioning of sludge, using the effect of low-temperature plasma. Primary sludge from the municipal wastewater treatment plant in GorzĂłw was analysed. The sludge was conditioned electrochemically, chemically with calcium hydroxide and dihydrogen dioxide, and using a combined method â electrochemical and chemical. For each conditioned sludge its settlement characteristics, hydration, dry mass content, organic and mineral
substances, calculated and measured specific filtration resistance, effectiveness of filtration, iron content in ash, as well as energy-consumption in the process were determined. For the electrochemical, chemical and combined processes of primary sludge conditioning, their courses were compared. It was proved that (1) processes of conditioning cause changes in properties of primary sludge; (2) electrochemical conditioning causes mineralization
and stabilization; (3) dewaterability of sludge is improved; (4) the process can be supported using additionally calcium hydroxide and dihydrogen dioxide; (5) optimization of the process can be performed only by improving the effectiveness of selected process parameters
Transient field-resolved reflectometry at 50-100 THz
Transient field-resolved spectroscopy enables studies of ultrafast dynamics in molecules, nanostructures, or solids with sub-cycle resolution, but previous work has so far concentrated on extracting the dielectric response at frequencies below 50 THz. Here, we implemented transient field-resolved reflectometry at 50-100 THz(3-6 mu m) with MHz repetition rate employing 800 nm few-cycle excitation pulses that provide sub-10 fs temporal resolution. The capabilities of the technique are demonstrated in studies of ultrafast photorefractive changes in semiconductors Ge and GaAs, where the high frequency range permits to explore the resonance-free Drude response. The extended frequency range in transient field-resolved spectroscopy can further enable studies with so far inaccessible transitions, including intramolecular vibrations in a large range of systems. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License
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EERC Center for Biomass Utilization 2005
Biomass utilization is one solution to our nationâs addiction to oil and fossil fuels. What is needed now is applied fundamental research that will cause economic technology development for the utilization of the diverse biomass resources in the United States. This Energy & Environmental Research Center (EERC) applied fundamental research project contributes to the development of economical biomass utilization for energy, transportation fuels, and marketable chemicals using biorefinery methods that include thermochemical and fermentation processes. The fundamental and basic applied research supports the broad scientific objectives of the U.S. Department of Energy (DOE) Biomass Program, especially in the area of developing alternative renewable biofuels, sustainable bioenergy, technologies that reduce greenhouse gas emissions, and environmental remediation. Its deliverables include 1) identifying and understanding environmental consequences of energy production from biomass, including the impacts on greenhouse gas production, carbon emission abatement, and utilization of waste biomass residues and 2) developing biology-based solutions that address DOE and national needs related to waste cleanup, hydrogen production from renewable biomass, biological and chemical processes for energy and fuel production, and environmental stewardship. This project serves the public purpose of encouraging good environmental stewardship by developing biomass-refining technologies that can dramatically increase domestic energy production to counter current trends of rising dependence upon petroleum imports. Decreasing the nationâs reliance on foreign oil and energy will enhance national security, the economy of rural communities, and future competitiveness. Although renewable energy has many forms, such as wind and solar, biomass is the only renewable energy source that can be governed through agricultural methods and that has an energy density that can realistically compete with, or even replace, petroleum and other fossil fuels in the near future. It is a primary domestic, sustainable, renewable energy resource that can supply liquid transportation fuels, chemicals, and energy that are currently produced from fossil sources, and it is a sustainable resource for a hydrogen-based economy in the future
Community engagement and professionalization: Emerging tensions
© 2019 by Emerald Publishing Limited. An increase in community engagement by governments across Australiaâs three-tiered federal polity conforms to international trends. It represents a multidimensional institutionalization of participatory democracy designed to involve the public in decision-making. Increasingly, it is a practice which displays the markers of professionalization, including (self-described) professionals, professional associations and a code of ethics. The individuals who design, communicate, and facilitate community engagement are placed in a unique position, whereas most professions claim to serve both their client or employer and a greater public good, community engagement practitioners play these roles while also claiming to serve as âguardiansâ of democratic processes. Yet the claimed professionalization of community engagement is raising some questions: Is community engagement really a profession â and by what criteria ought this be assessed? What tensions do community engagement practitioners face by âserving multiple masters,â and how do they manage these? More pointedly, how can ethics inform our understanding of community engagement and its professionalization? This chapter examines the case for the practice of community engagement as a profession using Noordegraafâs (2007) pillars of pure professionalism as a guide. It then explores some practical examples of the tensions practitioners may experience. The chapter concludes by reflecting on the future direction of community engagement given its positioning
Red Aesthetics, Intermediality and the Use of Posters in Chinese Cinema after 1949
Abstract: This article focuses on the aesthetic and affective techniques of saturation through which posters legitimated the Party-State in Maoâs China by closing the gap between everyday experience and political ideology. Propaganda posters were designed to put into practice the principle of unity, as conceptua- lised by Mao Zedong. The argument posits that while the âposterâ is normally a printed edition of a painting or design intended for mass distribution in this way, the term may fairly be deployed to capture other cultural objects that function as âpostersâ, in that they provide public, political information that expresses or con- structs a political self in aesthetic form. This approach requires a metonymic understanding of a visual field in which cultural objects are interrelated and mutually reinforcing. The essay draws on recent in-depth interviews with poster artists of the 1960s and 1970s
Fear and Exploration in European Starlings (Sturnus vulgaris): A Comparison of Hand-Reared and Wild-Caught Birds
The revision of EU legislation will ban the use of wild-caught animals in scientific procedures. This change is partially predicated on the assumption that captive-rearing produces animals with reduced fearfulness. Previously, we have shown that hand-reared starlings (Sturnus vulgaris) indeed exhibit reduced fear of humans compared to wild-caught conspecifics. Here, we asked whether this reduction in fear in hand-reared birds is limited to fear of humans or extends more generally to fear of novel environments and novel objects. Comparing 6â8 month old birds hand-reared in the lab with age-matched birds caught from the wild as fledged juveniles a minimum of 1 month previously, we examined the birds' initial reactions in a novel environment (a small cage) and found that wild-caught starlings were faster to initiate movement compared to the hand-reared birds. We interpret this difference as evidence for greater escape motivation in the wild-caught birds. In contrast, we found no differences between hand-reared and wild-caught birds when tested in novel object tests assumed to measure neophobia and exploratory behaviour. Moreover, we found no correlations between individual bird's responses in the different tests, supporting the idea that these measure different traits (e.g. fear and exploration). In summary, our data show that developmental origin affects one measure of response to novelty in young starlings, indicative of a difference in either fear or coping style in a stressful situation. Our data contribute to a growing literature demonstrating effects of early-life experience on later behaviour in a range of species. However, since we did not find consistent evidence for reduced fearfulness in hand-reared birds, we remain agnostic about the welfare benefits of hand-rearing as a method for sourcing wild birds for behavioural and physiological research
Democracia vs. eficiĂȘncia: como alcançar equilĂbrio em tempo de crise financeira
Resumo A administração pĂșblica Ă© forçada a encontrar um equilĂbrio entre eficiĂȘncia e democracia na definição da sua agenda e curso de ação. Uma das caracterĂsticas da administração pĂșblica Ă© que todas as decisĂ”es devem refletir valores democrĂĄticos, para alĂ©m de serem eficientes. No entanto, a reforma administrativa, motivada por dificuldades financeiras, tende a destacar a importĂąncia do desempenho financeiro, em detrimento dos aspetos democrĂĄticos nas polĂticas de gestĂŁo pĂșblica. Esta pesquisa visa analisar a relação e tensĂŁo entre a eficiĂȘncia e a democracia Ă luz da mais recente crise financeira global. O trabalho utiliza uma abordagem quantitativa e recolhe dados de governos locais portugueses para testar o argumento de uma relação linear inversa de desempenho financeiro e procedimentos democrĂĄticos. Os resultados confirmam o argumento de uma relação inversa, definida por Waldo (1948). Adicionalmente, os resultados tambĂ©m permitem concluir que a crise financeira evidenciou o efeito negativo dos procedimentos democrĂĄticos no desempenho financeiro
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