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991.
Bettini PJ 《Hospital materiel management quarterly》1999,21(2):59-70
In the last two decades, manufacturing businesses throughout the United States have learned that the most important way to ensure the maximum potential of their manufacturing systems when implementing manufacturing resource planning is how they approach the implementation itself--not just their choice of or expenditure for software. 相似文献
992.
993.
Basch P 《Medical economics》1999,76(23):166, 168, 171
994.
William P. Dukes Philip C. English Sean M. Davis 《The Journal of Financial Research》2006,29(2):235-252
The Securities and Exchange Commission is currently reviewing Rule 12b‐1, which governs how fund advisors may pay for the distribution of fund shares. We provide evidence that even after adjusting for economies of scale, funds with 12b‐1 fees have higher expense ratios net of the 12b‐1 fees than do funds without such fees. This finding suggests that 12b‐1 fees are more than just a deadweight cost. We also demonstrate that 12b‐1 fees are highest for funds that ultimately fail, that the proportion of funds with 12b‐1 fees is increasing over time, and that the level of those fees is also increasing over time. 相似文献
995.
D.P. O'Brien 《Economic journal (London, England)》2002,112(483):F581-F583
996.
P.J. Drake 《Australian economic history review》1991,31(1):90-96
From the early seventeenth to the late nineteenth century, the Mexican silver dollar was accepted as a common currency of Southeast Asia, though local governments issued their own dollars based on it. The decline of the value of silver relative to gold after 1870 introduced a gradual shift to official currencies pegged to a gold standard in Europe. 相似文献
997.
D P Chynoweth J M Owens A A Teixeira P Pullammanappallil S S Luniya 《Water science and technology》2006,53(8):177-185
The technical feasibility of applying leachbed high-solids anaerobic digestion for reduction and stabilization of the organic fraction of solid wastes generated during space missions was investigated. This process has the advantages of not requiring oxygen or high temperature and pressure while producing methane, carbon dioxide, nutrients, and compost as valuable products. Anaerobic biochemical methane potential assays run on several waste feedstocks expected during space missions resulted in ultimate methane yields ranging from 0.23 to 0.30 L g-1 VS added. Modifications for operation of a leachbed anaerobic digestion process in space environments were incorporated into a new design, which included; (1) flooded operation to force leachate through densified feedstock beds; and (2) separation of biogas from leachate in a gas collection reservoir. This mode of operation resulted in stable performance with 85% conversion of a typical space solid waste blend, and a methane yield of 0.3 Lg per g VS added after a retention time of 15 days. These results were reproduced in a full-scale prototype system. A detailed analysis of this process was conducted to design the system sized for a space mission with a six-person crew. Anaerobic digestion compared favorably with other technologies for solid waste stabilization. 相似文献
998.
E I P Volcke K V Gernaey D Vrecko U Jeppsson M C M van Loosdrecht P A Vanrolleghem 《Water science and technology》2006,54(8):93-100
In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water streams on the performance of a WWTP is assessed in a simulation study, using the Benchmark Simulation Model no. 2 (BSM2), that includes the processes describing sludge treatment and in this way allows for plant-wide evaluation. Comparison of performance of a WWTP without reject water with a WWTP where reject water is recycled to the primary clarifier, i.e. the BSM2 plant, shows that the ammonium load of the influent to the primary clarifier is 28% higher in the case of reject water recycling. This results in violation of the effluent total nitrogen limit. In order to relieve the main wastewater treatment plant, reject water treatment with a combined SHARON-Anammox process seems a promising option. The simulation results indicate that significant improvements of the effluent quality of the main wastewater treatment plant can be realized. An economic evaluation of the different scenarios is performed using an Operating Cost Index (OCI). 相似文献
999.
This paper deals with the performances obtained in full scale anaerobic digesters co-digesting waste activated sludge from biological nutrients removal wastewater treatment plants, together with different types of organic wastes (solid and liquid). Results showed that the biogas production can be increased from 4000 to some 18,000 m3 per month when treating some 3-5 tons per day of organic municipal solid waste together with waste activated sludge. On the other hand, the specific biogas production was improved, passing from 0.3 to 0.5 m3 per kgVS fed the reactor, when treating liquid effluents from cheese factories. The addition of the co-substrates gave minimal increases in the organic loading rate while the hydraulic retention time remained constant. Further, the potentiality of the struvite crystallisation process for treating anaerobic supernatant rich in nitrogen and phosphorus was studied: 80% removal of phosphorus was observed in all the tested conditions. In conclusion, a possible layout is proposed for designing or upgrading wastewater treatment plants for biological nutrients removal process. 相似文献
1000.
A substantial number of last reported transactions for stocks trading on the New York Stock Exchange occur inside the quoted closing bid-ask spread. The tendency to close inside the spread results in price change magnitudes much smaller than those predicted from binomial models. Moreover, although the change magnitude is biased by the underlying trend of the market, the distribution of next day price change relatives is largely unaffected. The result is a systematic regularity between the location of today's close and tomorrow's close relative to the bid-ask spread. 相似文献