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排序方式: 共有518条查询结果,搜索用时 15 毫秒
511.
Nataša Novak Tušar Darja Maučec Mojca Rangus Iztok Arčon Matjaž Mazaj Magda Cotman Albin Pintar Venčeslav Kaučič 《Advanced functional materials》2012,22(4):820-826
Wet hydrogen peroxide catalytic oxidation (WHPCO) is one of the most important industrially applicable advanced oxidation processes (AOPs) for the decomposition of organic pollutants in water. It is demonstrated that manganese functionalized silicate nanoparticles with interparticle porosity act as a superior Fenton‐type nanocatalyst in WHPCO as they can decompose 80% of a test organic compound in 30 minutes at neutral pH and room temperature. By using X‐ray absorption spectroscopic techniques it is also shown that the superior activity of the nanocatalyst can be attributed uniquely to framework manganese, which decomposes H2O2 to reactive hydroxyls and, unlike manganese in Mn3O4 or Mn2O3 nanoparticles, does not promote the simultaneous decomposition of hydrogen peroxide. The presented material thus introduces a new family of Fenton nanocatalysts, which are environmentally friendly, cost‐effective, and possess superior efficiency for the decomposition of H2O2 to reactive hydroxyls (AOP), which in turn readily decompose organic pollutants dissolved in water. 相似文献
512.
Pomfret MB Demircan O Sukeshini AM Walker RA 《Environmental science & technology》2006,40(17):5574-5579
Solid oxide fuel cells (SOFCs) are electrochemical devices that rely on ion migration through a solid-state electrolyte to oxidize fuel and produce electricity. The present study employs Fourier transform infrared spectroscopy to quantify the exhaust of an SOFC operating with fuel flows of methane over Ni/YSZ cermet anodes and butane over Ni/YSZ and Cu/CeO2/YSZ cermet anodes. Data show that hydrocarbon fuels can participate in a variety of different reactions including direct electrochemical oxidation, various reforming processes, and surface-catalyzed carbon deposition. These findings have direct consequences for assessing the environmental impact of SOFCs in terms of the exhaust discharged from devices operating with common hydrocarbon fuel feeds. In the work presented below, a measure of fuel oxidation efficiency is found by comparing the partial pressure of CO2 (P(CO2)) in the SOFC exhaust to the partial pressure of CO (P(CO)). The fuel anode combination with the largest P(CO2)/P(CO) ratio is the C4H10 over Cu/CeO2 combination (0.628 +/- 0.016). The CH4 over Ni cell type has the second highest ratio (0.486 +/- 0.023). The C4H10 over Ni cell type gives a ratio of 0.224 +/- 0.001. Attempts to balance the carbon content of the fuel feed and exhaust lead to predictions of SOFC fuel oxidation mechanisms. 相似文献
513.
514.
Heather Troxell Aldrich Karen Salandanan Patricia Kendall Marisa Bunning Frank Stonaker Oktay Külen Cecil Stushnoff 《Journal of the science of food and agriculture》2010,90(15):2548-2555
BACKGROUND: Tomatoes (Solanum lycopersicum L.) are widely consumed and well known for their health benefits, many of which have been associated with the high levels of antioxidants present in tomatoes. With a growing interest in local and organic foods, it would be helpful to determine whether farmers could naturally improve the quality and antioxidant content of tomatoes for sale in local markets. This study evaluated antioxidant properties, quality attributes, and yield for 10 tomato cultivars grown for 2 years using certified organic and conventional practices. RESULTS: Cultivar and year effects impacted (P < 0.05) all tests conducted, while growing method influenced (P < 0.05) yield, soluble solids content, ascorbic acid, and antioxidant radical scavenging capacity. Even when accounting for year‐to‐year variability, cultivars in the highest groups had 1.35‐ to 1.67‐fold higher antioxidant levels than cultivars in the lowest groups. ‘New Girl’, ‘Jet Star’, ‘Fantastic’, and ‘First Lady’ were always in the highest groups, while ‘Roma’ and ‘Early Girl’ consistently had the lowest antioxidant content. CONCLUSION: Compared to production practices and environmental effects of years that are generally beyond the control of small‐scale producers, choice of cultivar provides the simplest and most effective means of increasing antioxidant properties. Knowledge of tomato cultivars with naturally higher antioxidant levels could assist smaller‐scale producers to grow fruit that may provide a competitive advantage and the opportunity to capitalize on the increasing popularity of locally grown, high‐quality fresh produce. Copyright © 2010 Society of Chemical Industry 相似文献
515.
Fasihi Shirehjini Oktay Babapour Mofrad Farshid Shahmohammadi Mohammadreza Karami Fatemeh 《Magma (New York, N.Y.)》2023,36(1):43-53
Magnetic Resonance Materials in Physics, Biology and Medicine - Despite the critical role of Magnetic Resonance Imaging (MRI) in the diagnosis of brain tumours, there are still many pitfalls in the... 相似文献
516.
Gustavo Gonzalez María Arévalo Annalisa Chiappone Enrique Martínez Campos Candido Fabrizio Pirri Ignazio Roppolo Paula Bosch 《大分子材料与工程》2023,308(11):2300118
Light- induced polymeric 3D printing is becoming a well-established fabrication method, showing manifold advantages such as control of the local chemistry of the manufactured devices. It can be considered a green technology, since the parts are produced when needed and with minimum amount of materials. In this work 3D printing is combined with another green technology, microwave-assisted reaction, to fabricate objects of complex geometry with controllable surface properties, exploiting the presence of remaining functional groups on the surface of 3D printed specimens. In this context, surface functionalization with different amines is studied, optimizing formulations, reaction times, and avoiding surface deterioration. Then, two different applications are investigated. MW-functionalized filter-type structures have been tested against Staphylococcus aureus bacteria, showing high bactericidal activity on the surface along all areas of the complex-shaped structure. Second, a fluidic chip composed of three separated channels is 3D printed, filled with different amine-reactive dyes (dansyl and eosine derivatives), and made to react simultaneously. Complete and independent functionalization of the surface of the three channels is achieved only after 2 min of irradiation. This study demonstrates that light induced 3D printing and microwave-induced chemistry can be used together effectively, and used to produce functional devices. 相似文献
517.
Essam Hebishy Oktay Yerlikaya Jennifer Mahony Asli Akpinar Derya Saygili 《International Journal of Dairy Technology》2023,76(4):779-800
For dairy processors, spoilage and pathogenic spore-forming bacteria are key sources of concern, not only due to their ability to remain dormant in a desiccated state in powders and to survive heat treatments, but also their ability to form biofilms in the vegetative state that lead to contamination of foods. These include members of the genera Bacillus, Geobacillus, Anoxybacillus, Brevibacillus, Paenibacillus and Clostridium, many of which are associated with food poisoning and spoilage. Here, we review the common bacterial species that form spores in whey powders and their sources and provide insights into their risks and strategies to control them. 相似文献
518.
Nabeeha Amatullah Azmi Azhaili Baharun M sl m Arıcı Siti Halipah Ibrahim 《建筑学研究前沿(英文版)》2023,12(2):361-385
Mosques have intermittent operational schedules with short-term occupancy during the five daily prayers. The occupancy level of the daily prayers is a fraction compared to the mandatory Friday prayers with full occupancy. Usually, the same thermal control mechanism is operated within the same large prayer hall to maintain the thermal comfort of the occupants. Yet, the comfort requirements are often not met due to the short span of operation during prayer times. Nevertheless, mosques have a very high energy usage as the same energy-intensive system is operated even during minimal occupancy profiles. The current research aims at using a passive approach towards design to achieve the comfort conditions during the low occupancy daily prayer times without employing mechanical intervention. Numerical simulations are carried out on a validated model of the case study building to investigate the impact of the west-facing Qiblah wall as the congregation stands in proximity to this wall. The design alternatives are tested in conjunction with ventilation strategies to holistically assess the thermal comfort of the occupants. Results show that as much as 4–6°C reduction in indoor wall surface temperature can be achieved with a suitable Qiblah wall design, which reduces the mean radiant temperature of the occupants by 2–4°C. Combined with ventilation strategies, thermal comfort can be significantly improved by at least 40% for the prayers during the hottest times of the day, and as much as 80% for night-time prayers. Results suggest that suitable comfort conditions can be achieved without the need for air-conditioning for at least two or three of the five daily prayers. 相似文献