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51.
Uri Goren Avi Aharoni Mario Kummel Rami Messalem Igor Mukmenev Asher Brenner Vitaly Gitis 《Separation and Purification Technology》2008,61(2):193-203
Flocculation, adsorption onto powered activated carbon (PAC), and ultrafiltration (UF), alone and in combination, were tested for tertiary treatment of the secondary effluent from municipal wastewater treatment at the Ashkelon plant (in southern Israel). Encouraging and reliable results of total organic carbon (TOC) of <3 mg/l were achieved with a combination of 130 mg/l FeCl3, 0.6 g/l PAC and UF. The relative contribution of the UF membrane to the reduction of TOC changed with the molecular weight cut-off (MWCO) of the membrane, from a negligible 2.9% for a 100-kDa-MWCO membrane to 17% for 10- and 2-kDa membranes. The latter membranes, however, developed significant fouling, with a 35% drop in flux during first 30 min of the filtration cycle. The flux drop for the 50- and 100-kDa membranes was in the low range of 3%. The optimal MWCO interval of 20- to 50-kDa in combination with flocculation/PAC pretreatment gave a significant reduction in organic content with minimal membrane fouling. Detailed GC–MS analysis showed that the combined treatment gave very efficient retention of organic compounds with molecular weights below 800 Da, with the consequent absence of harmful compounds in the tertiary effluent. It was therefore concluded that the recommended flocculation/adsorption protocol constitutes an effective pretreatment for UF and that the obtained tertiary effluent can be used for unrestricted irrigation. 相似文献
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Mirko Weidner Oscar Borrero-López Mark Hoffman Avi Bendavid 《Thin solid films》2010,518(18):5242-5248
The effect of substrate and surface roughness on the contact fracture of diamond-like carbon coatings on brittle soda-lime glass substrates has been investigated. The average surface roughness (Ra) of the examined samples ranged from 15 nm to 571 nm. Contact damage was simulated by means of spherical nanoindentation, and fracture was subsequently assessed by focused ion beam microscopy. It was found that, in the absence of sub-surface damage in the substrate, fracture occurs in the coating in the form of radial, and ring/cone cracks during loading, and lateral cracks during unloading. Increasing the surface roughness results in a decrease in the critical load for crack initiation during loading, and in the suppression of fracture modes during unloading from high loads. When sub-surface damage (lateral cracks) is present in the substrate, severe spalling takes place during loading, causing a large discontinuity in the load-displacement curve. The results have implications concerning the design of damage-tolerant coated systems consisting of a brittle film on a brittle substrate. 相似文献
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• | One major change in the world of international business and finance is the growing role of private equity investments in firms in emerging markets. In little more then four years, since 2003, the money raised by international, primarily American private equity funds for investment in emerging markets went up about ten times, from $3.5B to $35B. |
• | This paper provides a multidimensional analysis and discussion on the role of private equity funds in the globalization process of firms from emerging markets. The discussion begins with development economics, focusing on financial markets development and sector specific capital, proceeds to a discussion of local comparative advantage and intangible trade costs in the process of globalization, and continues with a discussion of imperfect contracts and financial contracting based on recent research in financial economics. |
• | The multidimensional character of the research is congruent with the nature of globalization and international business. Investment of private equity funds in emerging markets is shown as a new form of foreign direct investment dubbed FFDI (financial foreign direct investment). |
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This paper investigates how durability, energy efficiency and indoor air quality can be improved through proper detailing. The energy implications of air-tight construction are evaluated for terrace and semi-detached houses. 相似文献
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Simulations among concurrent-write PRAMs 总被引:1,自引:0,他引:1
This paper is concerned with the relative power of the two most popular concurrent-write models of parallel computation, the PRIORITY PRAM [G], and the COMMON PRAM [K]. Improving the trivial and seemingly optimalO(logn) simulation, we show that one step of a PRIORITY machine can be simulated byO(logn/(log logn)) steps of a COMMON machine with the same number of processors (and more memory). We further prove that this is optimal, if processor communication is restricted in a natural way.Support for this research was provided by NSF Grants MCS-8402676 and MCS-8120790, DARPA Contract No. N00039-84-C-0089, an IBM Faculty Development Award, and an NSERC postgraduate scholarship. 相似文献
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In a recent issue of Information and Management, Neumann and Segev developed a correlation analysis of user evaluation of information characteristics (IC) for system improvement. The purpose of this note is to offer a modest extension to their theory which is otherwise viewed as an excellent attempt at modeling realistic aspects of the user IC evaluation. This empirical study factor analyzes the four IC variables. These variables (Content, Accuracy, Frequency, and Recency) are also ranked according to their relative dominance. The differentiation level among these IC variables is found to be low. Thus, the four variables have been reduced to one factor. Moreover, a formula for an index of IC has been set. Thus, it is possible to condense these four variables into one factor. 相似文献