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排序方式: 共有182条查询结果,搜索用时 15 毫秒
1.
The surface activity of spent sulphite liquor (SSL) and the separation of surface active components by foam fractionation were studied. The maximum activity (lowest surface tension) of SSL was observed at a high pH. The surface tension was found to be 42 mN/m and 38 mN/m at acidic and basic pH values, respectively, and also a maximum foaminess (Σ) of 7 min was observed at pH 10. Foam fractionation reduced the surfactant concentration by 90% at an optimum pH of 10. The surfactants were concentrated in the collapsed foam as shown by the fact that the critical micelle concentrations of the unfractionated SSL and foam were 70% (v/v) and 10% (v/v), respectively. The removed surfactants were concentrated in 20% of the original liquid volume. 相似文献
2.
The spectrum decision concept in Cognitive Radio Ad-Hoc Networks (CRAHNs) introduces important challenges. These include the time-dependent SNR observations of individual CRAHN users due to the fading and shadowing effects in the licensed channels, the necessity of fusion mechanisms for accurate decisions, and the difficulties depending on multi-hop deployment. Considering these challenges, in this paper, we propose a dynamic, cooperative and distributed spectrum decision mechanism in order to decide the channel usage in CRAHNs accurately. The proposed mechanism introduces the SNR Tracking System which considers the time-varying local SNR observations and decisions of the CRAHN users. The proposed mechanism employs a distributed Weighted Fusion Scheme (WFS), to combine the individual decisions and hence, to obtain the cooperative decision. The proposed spectrum decision mechanism adapts itself dynamically to the multi-hop architecture of the network. The performance of the proposed mechanism is compared to some conventional fusion mechanisms based on the AND, OR and MAJORITY rules, and it is shown that the proposed weighted mechanism gives lower false alarm and higher detection probabilities compared to the conventional fusion mechanisms. 相似文献
3.
Erdem Tevfik Ozdemir Serdar Yildirim Berk Ozler Tuncay Dikici Mustafa Erol Metin Yurddaskal 《International Journal of Applied Ceramic Technology》2023,20(6):3775-3785
In this study, manganese ferrite (MnFe2O4) nanoparticles were produced through flame spray pyrolysis (FSP). To investigate the effects of heat treatment, the nanoparticles were annealed between 400 and 650°C for 4 h in air in a comparative manner. The structural, chemical, morphological, and magnetic properties of the nanoparticles were evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM), respectively. The XRD results showed that the nanoparticles synthesized by the FSP method exhibited the MnFe2O4 spinel ferrite structure. The annealing process led to the decomposition of MnFe2O4 into various phases. According to the morphological analysis, the as-synthesized particles were hemispherical–cubic in shape and had an average particle size of less than 100 nm. In addition, the chemical bond structures of the nanoparticles were confirmed in detail by XPS elemental analysis. The highest saturation magnetization was recorded as 33.50 emu/g for the as-produced nanoparticles. The saturation magnetization of the nanoparticles decreased with increasing annealing temperature, while coercivity increased. 相似文献
4.
The ability to transmit particles into the ablation region of an aerosol mass spectrometer determines in part the lower size limit for particles that can be analyzed. A large fraction of small particles (< 100 nm) are lost due to processes such as Brownian diffusion that broaden the particle beam. In this work, electrostatic focusing is used to overcome the limits of aerodynamic focusing in the analysis of nanometer-sized particles by aerosol mass spectrometry. A simple tube lens is used to focus charged particles into the ablation laser beam path. The diameter of the focused beam is smaller than the fundamental aerodynamic limit imposed by Brownian motion. Measured enhancements of the hit rate for particles between 21 and 33 nm diameter are between 3 and 6. These values are lower limits for the true enhancements. The lens is also energy selective and can be used to select the mass (size) of the particles being analyzed. 相似文献
5.
Gabriel S.Esterhuizen I.Berk Tulu Dave F.Gearhart Heather Dougherty Mark Van Dyke 《矿业科学技术学报(英文版)》2021,31(1):103-110
Longwall gateroad entries are subject to changing horizontal and vertical stress induced by redistribution of loads around the extracted panel. The stress changes can result in significant deformation of the entries that may include roof sag, rib dilation, and floor heave. Mine operators install different types of supports to control the ground response and maintain safe access and ventilation of the longwall face. This paper describes recent research aimed at quantifying the effect of longwall-induced stress changes on ground stability and using the information to assess support alternatives. The research included monitoring of ground and support interaction at several operating longwall mines in the U.S., analysis and calibration of numerical models that adequately represent the bedded rock mass, and observation of the support systems and their response to changes in stress. The models were then used to investigate the impact of geology and stress conditions on ground deformation and support response for various depths of cover and geologic scenarios. The research results were summarized in two regression equations that can be used to estimate the likely roof deformation and height of roof yield due to longwall-induced stress changes. This information is then used to assess the ability of support systems to maintain the stability of the roof. The application of the method is demonstrated with a retrospective analysis of the support performance at an operating longwall mine that experienced a headgate roof fall. The method is shown to produce realistic estimates of gateroad entry stability and support performance, allowing alternative support systems to be assessed during the design and planning stage of longwall operations. 相似文献
6.
Bruna Panizzutti Chiara C. Bortolasci Briana Spolding Srisaiyini Kidnapillai Timothy Connor Mark F. Richardson Trang T. T. Truong Zoe S. J. Liu Gerwyn Morris Laura Gray Jee Hyun Kim Olivia M. Dean Michael Berk Ken Walder 《International journal of molecular sciences》2021,22(13)
Recent reports suggest a link between positive regulation of the Hippo pathway with bipolar disorder (BD), and the Hippo pathway is known to interact with multiple other signaling pathways previously associated with BD and other psychiatric disorders. In this study, neuronal-like NT2 cells were treated with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), valproate (0.5 mM), or vehicle control for 24 h. Genome-wide mRNA expression was quantified and analyzed using gene set enrichment analysis (GSEA), with genes belonging to Hippo, Wnt, Notch, TGF- β, and Hedgehog retrieved from the KEGG database. Five of the eight drugs downregulated the genes of the Hippo pathway and modulated several genes involved in the interacting pathways. We speculate that the regulation of these genes, especially by aripiprazole, clozapine, and quetiapine, results in a reduction of MAPK and NFκB pro-inflammatory signaling through modulation of Hippo, Wnt, and TGF-β pathways. We also employed connectivity map analysis to identify compounds that act on these pathways in a similar manner to the known psychiatric drugs. Thirty-six compounds were identified. The presence of antidepressants and antipsychotics validates our approach and reveals possible new targets for drug repurposing. 相似文献
7.
Turkey is one of the most energy import dependent countries in the world, suffering deeply from the economic and strategic burdens of oil importation. Our purpose is to determine the factors behind the crude oil import policy of Turkey and to measure their contribution to a well-organized import strategy. We implemented a principle component analysis to construct an Oil Import Vulnerability Index (OIVI) based on four factors, which are crude oil import dependency of primary energy consumption, crude oil import bill as a share of Gross Domestic Product (GDP), non-diversification of import sources, and share of oil in total energy import. The contribution of these factors to the OIVI is found to be approximately equal. While an overall deterioration in the OIVI has been observed during periods of increasing oil prices, better diversification of oil import sources has lead to significant improvements. We suggest Turkish policy-makers implement sound policies, emphasizing diversification of crude oil import sources and reduction of the share of crude oil in primary energy imports to increase energy supply security. This study has also demonstrated that it is possible to construct an index representing crude oil vulnerability caused by import dependency. 相似文献
8.
Kennard Betsy D.; Clarke Greg N.; Weersing V. Robin; Asarnow Joan Rosenbaum; Shamseddeen Wael; Porta Giovanna; Berk Michele; Hughes Jennifer L.; Spirito Anthony; Emslie Graham J.; Keller Martin B.; Wagner Karen D.; Brent David A. 《Canadian Metallurgical Quarterly》2009,77(6):1033
In this report, we conducted a secondary analysis of the Treatment of SSRI-Resistant Depression in Adolescents (TORDIA) study to explore the impact of specific cognitive–behavioral therapy (CBT) treatment components on outcome. In TORDIA, 334 youths (ages 12 to 18 years) with major depressive disorder who had failed to respond to an adequate course of selective serotonin reuptake inhibitor (SSRI) medication were randomized to a medication switch (either to an alternative SSRI or venlafaxine) with or without 12 weeks of adjunctive CBT. Participants who had more than 9 CBT sessions were 2.5 times more likely to have adequate treatment response than those who had 9 or fewer sessions. CBT participants who received problem-solving and social skills treatment components, controlling for number of sessions and other confounding variables, were 2.3 and 2.6 times, respectively, more likely to have a positive response. These preliminary findings underscore the importance of receiving an adequate number of sessions to attain an adequate clinical response. Finally, social skills and problem solving may be active elements in CBT for adolescent depression and should be considered in treatment by those working with seriously depressed youths. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
L Madlensky TC Berk BV Bapat RS McLeod J Couture D Baron T Hiruki M Redston Z Cohen S Gallinger 《Canadian Metallurgical Quarterly》1995,5(2):355-360
Hereditary nonpolyposis colorectal cancer (HNPCC) is a genetic disorder characterized by a strong family history of colorectal and extracolonic cancers, usually at a young age. This article presents a new provincial service for families with HNPCC. The Steve Atanas Stavro Familial Gastrointestinal Cancer Registry at Mount Sinai Hospital is accruing patients that meet a set of criteria establishing a putative diagnosis of HNPCC. The objectives of the Registry are to develop and assess patient pedigrees, to coordinate screening procedures for at-risk persons, to maintain a prospective database of patient information, to provide education and support for families and to contribute to research. To date, surgeons and patients are the most common referral sources, while oncologists and geneticists are the least common. The ultimate goal of the HNPCC service is the secondary prevention of cancer and a corresponding decrease in mortality for HNPCC family members. 相似文献
10.
Solid state electronic ballasts promise significant energy savings in the lighting systems of large buildings. However, organizational factors and standard operating procedures may inhibit the adoption of this technology in the large, bureaucratic public and private sector organizations which represent the major potential users of this technology. 相似文献