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Moustafa M. S. Sanad Mohamed M. Rashad El‐Sayed A. Abdel‐Aal Mohamed F. El‐Shahat Kevin W. Powers 《International Journal of Applied Ceramic Technology》2014,11(5):864-871
Molybdenum‐doped cordierite ceramics have been fabricated through facile combined techniques, coprecipitation followed by solid state. XRD results revealed that α‐cordierite phase is predominated with increasing Mo6+ ion content. The density measurements showed that the bulk density reduced to the minimum value of 0.61 g/cm3, which corresponds to the maximum porosity of about 76.8% at 5% Mo6+ ion. The dielectric permittivity (ε) of pure cordierite is decreased with increasing Mo6+ ion content. The minimum dielectric loss of Mo‐doped cordierite at 1 MHz was equal 0.008 with 10% Mo6+, while at 1 GHz was equal 0.03 with 5% Mo6+. 相似文献
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Explaining the Formation of Online News Startups in France and the United States: A Field Analysis 下载免费PDF全文
This article examines the differential formation of online news startups in Toulouse, France, and Seattle, United States. While Seattle is home to many startups, in Toulouse there have been just 4—and only 1 continues publishing. Drawing on Bourdieu's field theory, we argue that amount and types of capital held by journalists in the 2 cities varied as a result of differences in journalism's position in the field of power. These differences shaped the extent of startup formation in each city and structured journalists' capacities to convert their capital into the resources needed to form startups (e.g., funding, credentials, partnerships). These findings are positioned in relation to literatures on journalism innovation and comparative media. 相似文献
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UNStudio Ben van Berkel Hannes Pfau Astrid Piber Jin Xing Hufton+Crow Seth Powers 《中国建筑装饰装修》2018,(4)
正UNStudio由Ben van Berkel和Caroline Bos创立,是一个国际性的建筑设计网络。拥有三个全方位服务的国际事务所,分别位于阿姆斯特丹、香港和上海。专于建筑、室内建筑、产品设计、城市发展和基础设施项目。地址:浙江省杭州市钱江新城富春路业主方:凯德集团建筑面积:392526m~2项目年份:2017醒目的裙楼之上坐落着两座流线型的高楼,从中可以饱览钱塘江和西湖的迷人风光。 相似文献
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M. M. S. Sanad M. M. Rashad E. A. Abdel-Aal M. F. El-Shahat K. Powers 《Journal of Materials Engineering and Performance》2014,23(3):867-874
Zirconium-cordierite ceramic composites have been synthesized by a co-precipitation method using MgCl2·6H2O, NaAlO2, Na2SiO3·5H2O, and ZrOCl2·8H2O as starting materials. XRD, FT-IR, and SEM techniques were employed to study the effect of zirconium on the crystal structure and microstructure of the samples. XRD results revealed that spinel MgAl2O4 and t-ZrO2 phases were predominant in the samples with low Zr4+ content (10 wt.%), whereas zircon ZrSiO4 was predominant with high Zr4+ content (≥15 wt.%). The densification behavior was improved from 30.4 to 44.6% of the theoretical density (2.6 g/cm3) at 15 wt.% of Zr4+. However, microhardness of the sintered samples was enhanced from 7.1 to 7.5 GPa with increasing the Zr4+ dose from 0 to 25 wt.%. On the other hand, the gradual increase in Zr4+ content from 0 to 25 wt.% led to suppression in the electrical resistivity (ρ) from 16.6 to 2.8 × 109 Ω/cm, respectively. In addition, the dielectric permittivity (ε) of the pure cordierite was decreased with Zr4+ ion addition. The maximum dielectric permittivity (ε) at low frequencies (10 MHz) was 18.7 at 10 wt.% Zr4+ content, whereas at high frequencies (1 GHz) it was 38.8 at 15 wt.% Zr4+ content. 相似文献
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Jing Peng Diane M. Barrett Shyam S. Sablani Nathan Anderson Joseph R. Powers 《Critical reviews in food science and nutrition》2017,57(14):2970-2995
Increasing consumer desire for high quality ready-to-eat foods makes thermal pasteurization important to both food producers and researchers. To be in compliance with the Food Safety Modernization Act (FSMA), food companies seek regulatory and scientific guidelines to ensure that their products are safe. Clearly understanding the regulations for chilled or frozen foods is of fundamental importance to the design of thermal pasteurization processes for vegetables that meet food safety requirements. This article provides an overview of the current regulations and guidelines for pasteurization in the U.S. and in Europe for control of bacterial pathogens. Poorly understood viral pathogens, in terms of their survival in thermal treatments, are an increasing concern for both food safety regulators and scientists. New data on heat resistance of viruses in different foods are summarized. Food quality attributes are sensitive to thermal degradation. A review of thermal kinetics of inactivation of quality-related enzymes in vegetables and the effects of thermal pasteurization on vegetable quality is presented. The review also discusses shelf-life of thermally pasteurized vegetables. 相似文献
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Nageshwar Tammineni Gülhan Ünlü Barbara Rasco Joseph Powers Shyam Sablani Caleb Nindo 《Journal of food science》2012,77(11):E342-E347
Abstract: Trout‐skin (Oncorhynchus mykiss) gelatin‐based films containing antioxidants (epigallocatechin gallate (EGCG), 50 and 250 ppm w/w) and green tea powder (1% and 20% w/w of gelatin) were tested for tensile strength, elastic modulus, and elongation, and oxygen and water vapor transmission rates, in vitro antioxidant activity using the DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) assay and effect on stabilizing cod‐liver oil held under mild thermal abuse conditions. Cod‐liver oil overlaid with films was stored at 40 °C for 20 d and analyzed for peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Antioxidant activity was retained in films containing green tea powder, but was reduced (P < 0.05) in EGCG films (20 d, 23 °C). Water vapor transmission rate of the films incorporated with antioxidants did not change significantly (P > 0.05), but the oxygen transmission rate for films with 50 ppm EGCG and 20% green tea powder was significant (P < 0.05). Other physical properties varied with antioxidant incorporation. The TBARS and PV of control oil increased from 0.05 ± 0.01 to 4.71 ± 0.30 g MDA/kg oil and from 3.6 ± 0.2 to 178.3 ± 24.5 millieq peroxides/kg oil, respectively, after 20 d. For cod‐liver oil covered with control or antioxidant‐containing films, TBARS remained below 0.37 g MDA/kg oil and PV below 7 millieq peroxides/kg oil. Incorporation of antioxidants to the films did not reduce oil oxidation (P > 0.05) at the levels tested and this was confirmed by activation energy calculations. The rate of oil oxidation was more dependent upon the inherent oxygen barrier property of the films than the presence of antioxidants. Practical Application: This research has the potential to enhance the utilization of fish skins, a valuable food processing by‐product, as edible films with natural antioxidants to extend the shelf life of foods. The film physical properties and barrier to oxygen and water are investigated. 相似文献
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Energy literacy, which encompasses broad content knowledge as well as affective and behavioral characteristics, will empower people to make appropriate energy-related choices and embrace changes in the way we harness and consume energy. Energy literacy was measured with a written questionnaire completed by 3708 secondary students in New York State, USA. Results indicate that students are concerned about energy problems (affective subscale mean 73% of the maximum attainable score), yet relatively low cognitive (42% correct) and behavioral (65% of the maximum) scores suggest that students may lack the knowledge and skills they need to effectively contribute toward solutions. High school (HS) students scored significantly better than middle school (MS) students on the cognitive subscale; gains were greatest on topics included in NY State educational standards, and less on topics related to “practical” energy knowledge such as ways to save energy. Despite knowledge gains, there was a significant drop in energy conservation behavior between the MS and HS students. Intercorrelations between groups of questions indicate energy-related behaviors are more strongly related to affect than to knowledge. These findings underscore the need for education that improves energy literacy by impacting student attitudes, values and behaviors, as well as broad content knowledge. 相似文献
9.
Robinson-Whelen Susan; Hughes Rosemary B.; Powers Laurie E.; Oschwald Mary; Renker Paula; Swank Paul R.; Curry Mary Ann 《Canadian Metallurgical Quarterly》2010,55(2):97
Objective: To evaluate the effects of a computerized disability-specific abuse assessment intervention on abuse awareness, safety self-efficacy, and safety promoting behaviors of women with diverse disabilities. Research Design: A randomized control group design was used, with the intervention group completing the assessment intervention both at Time 1 (T1) and 3 months later at Time 2 (T2) and control participants completing it for the first time at T2. Analyses compared intervention and control groups at T2 and evaluated change over time in intervention group participants. The relationship between outcome variables (abuse awareness, safety self-efficacy, safety behaviors) was also explored. Results: The intervention group had greater abuse awareness than the control group at T2, and abuse awareness increased from T1 to T2 among women in the intervention group, particularly among women who had experienced little or no abuse in the past year. Both abuse awareness and safety self-efficacy were significantly related to safety behaviors. Conclusions: The computerized program offers promise as a nonthreatening method of conducting abuse assessments among women with disabilities while also serving as an intervention to enhance abuse awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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