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Clean Indices of Common RingsSchoonmaker, Benjamin L. 01 November 2018 (has links)
Lee and Zhou introduced the clean index of rings in 2004. Motivated by this work, Basnet and Bhattacharyya introduced both the weak clean index of rings and the nil clean index of rings and Cimpean and Danchev introduced the weakly nil clean index of rings. In this work, we calculate each of these indices for the rings ℤ/nℤ and matrix rings with entries in ℤ/nℤ. A generalized index is also introduced.
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Does one repetition maximun in clean correlate with 20 meter sprint and countermovement jump?Sofie, Sivertsson January 2016 (has links)
Background: Crossfit is a high-volume training form and is popular among society and military communities because of its metabolic and physical challenging conditioning program. Crossfit includes both aerobic and anaerobic training and performers of Crossfit use all three different metabolic pathways, the phosphagen system, glycolysis and oxidative system. Similarities in movement pattern clean, countermovement jump (CMJ) and sprint running exist and also the use of stretch shortening cycle (SSC), which is a biomechanical function that is used in for example plyometric exercises. Recent research has reported correlation between weightlifting, countermovement jump (CMJ) and sprint, however, few of these studies have used female Crossfit performers. Aim: The aim of this study was to examine if there is a correlation between the performances of a clean and linear sprint time in 20 meter and if there is a correlation between the performance of clean and height in CMJ. Method: To participate, the women had to be a member of a Crossfit gym since five months back, and have five month of experience of practicing the clean exercise. The study had two different test sessions were the first session was for one repetition max in clean and session two was for 20 meter sprint and CMJ. Result: Fifteen females participated in the study and the correlation between clean and CMJ showed a strong correlation (r =0,74, r2=0,55) and when controlling clean and CMJ for body mass, the result showed a very strong correlation (r=0.88). The associations between clean and sprint showed a moderate to strong negative correlation (r =-0,52, r 2=0,27) and when controlling for body mass the result was (r =-0.54). The association between CMJ and sprint showed a strong correlation (r=-0.69, r2=0,48) and when controlling for body mass the correlation was (r =-0.71). Conclusion:Findings from this current study showed that there is a strong relationship between CMJ and clean among female Crossfit participants. This indicate that weightlifting exercise, in this case clean, can improve power exercises as jump height, but not to forget the importance of practicing jump movements as well. For further research it would be interesting if the participants were divided in groups depending on how long they had practiced in Crossfit. To see if there would be any different in clean, sprint and jump among these measurements, and maybe use both squat jump and CMJ as a test for jump to see the different in the result it might give.
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The influence of feedstock properties on gasification plant performanceSloan, Elizabeth Patricia January 1996 (has links)
No description available.
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Emissions of nitrogen oxides, particulates and toxic metals from fossil-and -waste-fired combustorsHassan, Sajid January 1997 (has links)
No description available.
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Benzyl alcohol oxidation in a phase-transfer catalytic microporous contactor reactorHall, David Wesley January 2002 (has links)
No description available.
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The use of biological methods for the assessment of oil contamination and bioremediationBundy, J. G. January 1999 (has links)
There is a concern that concentration-based targets for soil clean-up are arbitrary, and do not necessarily relate to the environmental threat posed by the residual contamination. The development of sensitive, reliable, and ecologically relevant biological tests for oil-polluted soils would address these problems, and form a valuable complement to chemical analysis. Three biological test systems were chosen for examining the impact of oil contamination on soil microbes: (1) lux-marked bacterial biosensors, (2) Biological carbon source utilization profiles, and (3) phospholipid fatty acid (PLFA) community profiles. This allowed the testing of effects at three different levels of ecological complexity: respectively, single species; culturable bacteria; and eubacteria and eukaryotes. The use of specific bioluminescent biosensors (i.e. with lux genes fused to promoters from hydrocarbon degradation pathways) allowed the rapid detection of different hydrocarbon classes. The bacterial biosensors were optimized for the assessment of hydrocarbon compounds. Development of quantitative structure-activity relationships (QSARs) increased understanding of their responses to hydrocarbons and other petroleum-derived compounds. The three biological methods were then used to monitor the nutrient-assisted bioremediation of oil-spiked soils in two separate microcosm experiments: (1) remediation of four crude oils and one refined oil compared using bacterial biosensors, and (2) effects of diesel on three different soil types, and effects of three refined oils on one soil type, assessed using Biolog and PLFA profiling. All three biological test methods were sensitive to the oil contamination levels applied in the microcosm experiments. Individual species (biosensor tests) gave different responses to different oils; however, the community-level responses showed no differences. The microbial communities of the three different soil types could still be distinguished after 14-15 weeks of hydrocarbon contamination. The community response of the contaminated soils had changed from that of the control soils after four weeks of bioremediation, and did not return in similarity to the control over the course of the experiment.
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Analysis of clean room conditions impact on labor productivity : case studyWoo, Jeyoung 18 June 2012 (has links)
The semiconductor industry follows what is known as Moore’s Law. Moore’s Law says that every 18 months computer chip storage capacity doubles and the intervals between developments in chip design become shorter and shorter. This is also true for the set dates for construction which are dictated by the semiconductor industry’s needs and production schedule.
This paper analyzes the impact of a clean room environment. It scrutinizes daily reports and interviews, based on two data sets that focus on a semiconductor wafer fabrication facility (FAB) construction project. Both data sets involve the same crew working on a FAB construction project in the U.S. Room conditions, however, differ. Aside from such working conditions, all elements for both groups are the same (crew skill level, weather, and season). This research is based on the installation, from February 2010 to January 2011 in Austin, Texas, of an access floor in a semiconductor FAB construction project. The total cost of the project was US$3.6 billion. Generally, a semiconductor FAB has raised access floors because cables and pipes are laid under the floors for maintenance and operation purposes.
The data for this paper is derived from the access floor installation. The project manager’s daily progress record documented the changes in labor productivity. The data on the number of crew and work-hours is computed based on this information. Labor productivity is defined here as the relationship between output and the labor time for its production. The formula is as follows:
Labor productivity = Output(Quantity) / Input(Work-hours) Eq. (1)
This study used Eq. (1) to measure labor productivity for two conditions (working in general conditions and working in a clean room conditions). Labor productivity was computed as follows: the unit of output (quantity) is sq. ft., and the unit of input (work-hours) is hours.
The questionnaires and interviews attempted to identify the factors affecting project performance: rework, crew interference, overcrowded work areas, and overtime (Garner, et al., 1979; Tucker, et al., 1980). Each section consisted of yes/no questions and one question seeking the interviewee’s opinion about how each problem was solved. The responses are summarized as follows:
The results indicate that, in the clean room environment, labor productivity fell by 28.85%. For future projects, this drop represents additional time and money that should be taken into account in the estimate of costs and the schedule duration. The interviews indicate that labor productivity was affected by other factors such as rework, tool availability, other crews not being finished, overcrowded work areas, as well as access to work area. / text
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Cleanroom establishment and processing implementation for electron dragRagucci, Anthony J., January 1900 (has links)
Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains x, 135 p.; also includes graphics. Includes bibliographical references (p. 131-135).
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Studies of alkali vapour removal from hot gases at 650°C by aluminosilicate sorbentsChrysohoidou, Dimitra January 1996 (has links)
New advanced combined cycle coal-fired power generation systems are dependent on improvements in gas turbine technology and the development of hot gas cleaning techniques. These techniques are not only necessary to meet environmentally accepted emission limits for SOx and NOx but also to prevent downstream equipment from corrosion and erosion. Volatile alkali vapours in the exhaust gases produced by either coal gasification or combustion lead to corrosion of the gas turbine blades resulting in reduced operating life. Consequently, alkali removal systems which can operate upstream of the gas turbine have been incorporated into the development of the clean coal technologies. A number of studies on alkali removal systems have been performed in the temperature range of 800°C - 1000°C. Solid aluminosilicates, such as emathlite, activated bauxite, kaolinite and Fuller's Earth, react with alkali vapours at high temperatures and therefore have been characterised as suitable alkali sorbents. Fuller's Earth was identified as potentially the most suitable sorbent for use in the UK at the specified operating temperatures. This material was studied in detail by McLaughlin (1990) for use in a fixed bed configuration within the British Coal Air-Blown Gasification Cycle. Recently, it has been recognised that if ceramic filters are used for the removal of fine particulates, operating temperatures for alkali sorption will have to drop to 400°C-600°C, since these filters fail mechanically at higher temperatures. Much of the alkali will condense under these conditions and be removed by the filtration stages. However, the residual alkali levels may still exceed the revised turbine inlet specification of 24 ppb wt. Hence further studies of alkali sorption are required in this lower temperature region. During this work, it proved difficult to obtain accurate results at temperatures as low as 600°C, because of the low level of vapour phase alkali. However, experiments were performed successfully at 650°C and atmospheric pressure, on the fixed bed sorption rig used previously for tests at 827°C and 927°C. Tests comparing Fuller's Earth and kaolin, showed kaolin to have a higher sorption capacity at this temperature. Fixed bed tests with sodium and potassium were performed with Fuller's Earth pellets. The runs were of 200-600 hrs duration, with 4.58 ppm wt NaCl (1.8 ppm wt Na), 5 %vol H2O and up to 160 ppmv HCl in the inlet gas stream. Alkali uptake profiles were generated from chemical analysis of precise layers of pellets removed from the bed. Extensive modifications and improvements in analytical procedures enabled a closure of the mass balance of >99% to be achieved for a 600 hr run. Alkali exit levels measured using alumina wool filter pads in the exit gas were of the order of 5-6 ppb wt. Fuller's Earth pellets which had been pre-treated in gasifier gas and which were therefore contaminated with carbon, were tested and no difference was observed in their Na characteristics. Element mapping techniques based on Scanning Electron Microscopy, confirmed that a shrinking core model for Fuller's Earth grains and kaolin pellets was appropriate. The 'two-reaction' mechanism proposed by McLaughlin (1990), was used to fit the experimental results at 650°C. Albite was identified by X-ray diffraction studies as the reaction product under high-acid conditions and nepheline under non-acid conditions. Exit gas analysis studies with an on-line monitor for HCl, showed the production of HCl to be directly connected with the presence of NaCl vapour and to increase significantly with the presence of water vapour in the system. However, the detailed reaction mechanism has not been identified yet. The theoretical model developed for the high temperature studies (McLaughlin, 1990), using the pellet-grain model and the 'tank-in-series' method of solution has been applied successfully at 650°C. Parameters were extracted by curve fitting theoretical to experimental Na uptake concentration bed profiles. To test the numerical methods and the Szekely assumptions used in the McLaughlin program, two new computer programs were developed. The first, tested the pellet-grain model for a single pellet and the second was developed to solve the model more rigorously with a variable-order, variable-time-step numerical method. The new fixed bed model also incorporates the effects of temperature and pressure on selected parameters. It was used to predict the performance of a full-scale unit operating at 650°C and 24 bara. The results indicate that a bed of Fuller's Earth pellets, 3-10 mm in diameter, 4 m long and 4 m wide can achieve exit alkali levels below 20 ppb wt in continuous operation for up to 24,000 hrs.
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Understanding the clean energy landscapeJanuary 2018 (has links)
0 / SPK / specialcollections@tulane.edu
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