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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Simultaneous extraction of hydrocarbons and heavy metals from contaminated soils.

Han, Xu January 2000 (has links)
Soil Washing is a promising alternative treatment method for contaminated site remediation. An industry contaminated site - the OMEX site was selected for the study, and several extraction additives (chelating agent and surfactant) were used to investigate the application of soil washing for the removal of heavy metals and hydrocarbons. The interactions and transport of the contaminants were studied by bench-scale experiments for both heavy metals and hydrocarbons. Soil characterization was performed before the experiments.The soil characterization indicated that the OMEX soil contained large amounts of Pb, Zn (heavy metal) and total petroleum hydrocarbons (TPH). The contaminant concentrations were 986 mg/kg of Pb, 284 mg/kg of Zn, and 29000 mg/kg of TPH. The contaminated soil was also high in moisture content, organic content and total organic carbon (TOC). From soil analyses on different particle size fractions, most contaminants were concentrated in the fine soil fraction, below 150gm, which constituted about 35% by weight of the contaminated soil.Heavy metal removal by chelating agents was conducted first. The results showed that 3% EDTA solution offered the highest removal efficiency for both Pb and Zn. About 90% of Pb and 65% of Zn were removed by using 3% EDTA solution for 29 hours. The extraction kinetics proved to be slow, reaching equilibrium in a relatively long time (more than 10 hours). In soil washing the solution pH had some effect on the removal of both Pb and Zn with marginally better removals observed at a lower pH. The experimental study indicated that the ratio of washing solution volume to soil weight (LIS) had little effect on the percentage removal of both Pb and Zn.In hydrocarbons removal tests, experiments verified that surfactant solutions can be effective in removing organics from coarse soil fraction, while some amount of surfactants were ++ / adsorbed by fine soil particles. Anionic surfactants such as SIDS exhibited less sorption capacity than nonionic surfactants due to the electrostatic repulsion of the former. 4% SDS solution had the highest TPH removal efficiency for OMEX soil, but the 2% SIDS solution was used as it produced only marginally lower results than the 4%. The percentage removal of TPH was about 78% by using 2% SIDS solution. The TPH removal by SDS solution was observed to be a slow and non-equilibrium process. Higher solution temperature can improve removal efficiency of TPH from OMEX soil. Combined washing with a chelating agent and a surfactant was effective in removing both heavy metals and hydrocarbons. Removals of 78% Pb, 82% Zn and 81% TPH were obtained from OMEX soil in the combination test. However, the TPH concentration in fine soil was still very high after washing and would need further treatment.
42

Sediment Pollution Investigation and Processing Technology Assessment of Kaohsiung Harbor, Taiwan

Chen, Chun-Ting 19 June 2012 (has links)
This study focuses on the Kaohsiung industrial pier sediment survey, assessment and feasibility study of the approach. In this study, field monitoring operations, including the close Salt Water River mouth area of the industrial port (area A), the far Salt Water River mouth area of the industrial port (area B) and for the factories and shipyards at the junction of the terminal area (area C), The sampling of sediments of three core and three surface sediments of area A that used as treating test at laboratory. The survey results show that the industrial pier some heavy metals in the sediment concentration is higher than the quality indicators in the sediment above the limit (ULV), especially copper and zinc. In addition, the concentration of heavy metals of industrial pier area A, B and C of the sediment at least one of them is than current soil control standard. Among them, the frequency of exceeding control standards of copper concentration is the highest, the surface sediments of area A, B and C were about 75%, 42% and 0% respectively, while the core sediments were about 20%, 90% and 15%. These results indicate that the industrial pier sediment required to carry out appropriate pre-treatment to reclamation land to recycling. After investigation, simulation and estimation, the required appropriate treatment sediment in order to landfill volume of industrial pier area A and B (Salt Water River mouth) were approximately 40,000 and 36,400 cubic meters, the total approximately 76,400 cubic meters. Industrial pier is located in the Salt Water River mouth, and therefore withstand the effects of pollutants of the upstream sources flowed in, and than the sediment quality was poor. Sediments were accumulated in the bottom should be removed and sediments at the upstream Salt Water River should be treated too, the remediation and pollution source control for the future to improve the sediment quality is the most important work in Taiwan. In this study, chemical washing and chemical oxidation of the two treatment technology for industrial pier sediment organic pollutants (total petroleum hydrocarbons (TPH) as the target pollutants) to deal with the feasibility test. Sediment to be processed was collected neart the industrial pier, the pH value of approximately 7.1, the moisture content was 43.9%, 20.1% organic matter content, while the particle size composition of mainly fine particles (silt + clay) to about 84.3% handling may be more difficult. The sediments of the TPH concentration of 8,691 mg / kg. Three surfactants Simple Green (SG), Triton X-100 (TX-100) and Tween 80 (TW80) were used at sediment washing test,washing with 60 pv and 5% (v / v) SG could remove 97.3% TPH at the end of the mud; 0.5% (v / v) TX-100 could remove 96.8% TPH; washing with 30 pv, 1% (v / v) TX-100 could remove 94.6% the TPH; washing with 10 pv, 5% (v / v) TX-100 could remove 96.7% TPH; but TW80 leaching ineffective. Oxidation processing, applied 6% H2O2 reaction 180 min, 58.2% of TPH could be removed. Connection of washing and oxidation treatment process, could be removed total of 86% of TPH. The sediment surface morphology before and after treatment were observed by SEM were not significantly different, no surfactant emulsion was left at sediment after treated, this result revealed the connection of washing and oxidation treatment process could remove most of TPH and less harmful to the environment was an available technique.
43

Factors affecting hand hygiene compliance in intensive care units: a systematic review

Lau, Chun-ling., 劉俊玲. January 2012 (has links)
Hospital-acquired, or nosocomial infections (HAIs) are the major source of mortality and morbidity for hospitalized patients. It is estimated that 7-10% patients developed HAIs during their hospital stays, with most patients got infected from intensive care units (ICU) [1,2]. Hand hygiene (HH) is recognized as the most easy and effective way to prevent HAIs. However, the observed hand hygiene compliance rates among healthcare workers (HCWs) have been regarded as unacceptably low, especially in ICU [3]. This literature review is to discuss the factors influencing the hand hygiene compliance among HCWs in ICU, in both the individual and institutional level, and suggest which factor was important in both levels. Recommendations in comprehensive approach on hand hygiene practices will also be included. / published_or_final_version / Public Health / Master / Master of Public Health
44

Handwashing station for rural Kenya

Sekercioglu Salim, Dogan January 2013 (has links)
FACT Around 2.6 billion people worldwide lack access to adequate sanitation and hygiene.  WHY SHOULD WE CARE? Hand washing with soap shows the greatest reduction in diarrhea morbidity (over 40%), and can also reduce respiratory tract infection by about one third.  WHAT ARE WE WAITING FOR? Despite the cost effectiveness of hand washing with soap, and the fact that it is a relatively simple behavior, encouraging good hand washing practice remains a challenge. WHAT IS THE PURPOSE? This project aims to spread hand hygiene in rural Kenyan households by engaging local manufacturers. In this project, World Bank’s Water and Sanitation Program (WSP) supported preliminary consumer research and product design work for a new affordable hand washing station.
45

Effects of micronization, ethanol washing, and enzymatic hydrolysis processing alone or in combination on trypsin inhibitors, lipoxygenase activities and selected “beany” flavour related compounds in soybean flour

Chen, Yuming Jr 19 June 2015 (has links)
Soybean production and consumption has increased in recent decades. However, trypsin inhibitor activity and “beany” flavour are two drawbacks limiting the utilization of soybean. In the present study, micronization, ethanol washing, and enzymatic hydrolysis (alone or in combination) were used to treat soybean. Micronization at 100 °C and 135 °C decreased the activity of both trypsin inhibitors (53% and 80% respectively), and lipoxygenase (51% and 99%, respectively). Ethanol increased the trypsin inhibitor activity while alcalase hydrolysis decreased its activity. Different treatment combinations affected trypsin inhibitor activity, with micronization having a major influence. “Beany” flavour related volatiles (hexanal, (E)- 2-hexenal, 1-hexanol, heptanal, (E)-2-octenal, (E)-2-nonenal, (E,E)-2,4-nonadienal, 2,4-decadienal, (E,E)-2,4-decadienal, 1-octen-3-ol, 2-pentylfuran and 3-octen-2-one) were significantly decreased with micronization. Ethanol effects varied with different volatiles. Soybean micronized at 135°C and washed with 65% ethanol was recommended for soybean processing due to its low trypsin inhibitor activity and low “beany” related volatile content.
46

A new magneto-rheological fluid (MRF) washing machine damper and a novel two-way-controllable MRF valve

Aydar, Gokhan. January 2006 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 123-127). Online version available on the World Wide Web.
47

Management of the mineral resource risk associated with near-density material in the beneficiation plant at Leeuwpan Coal Mine

Botha, Brendan William. January 1900 (has links)
Thesis (M.Sc.(Earth Science Practice & Management))--University of Pretoria, [2008]. / Abstract in English. Includes bibliographical references (leaves 85-88).
48

SUPEROVULATION AND EMBRYO COLLECTION IN WOOD BISON (Bison bison athabascae): TOOLS TO PRODUCE DISEASE-FREE EMBRYOS

2015 December 1900 (has links)
Reclamation of Canada’s threatened wood bison (Bison bison athabascae) herd is complicated by cattle diseases. As part of an overall goal to conserve bison genetics, five studies were conducted to develop or adapting present reproductive technologies to produce disease-free in vivo-derived wood bison embryos. In Chapter 4, the efficacy of pLH and hCG for inducing ovulation and whether the effect was related to the size of the dominant follicle at the time of treatment was examined in wood bison during the anovulatory season . Ovulation rate with hCG (94%) was nearly two times greater than with pLH (54%), and bison with a growing follicle of ≥10 mm had a greater ovulatory response than those of 8-9 mm. In Chapter 5, the efficacy of pLH and hCG after superstimulation with single or two doses (48 hours apart) of FSH diluted in 0.5% hyaluronan was determined in wood bison. A greater superovulatory ovarian response was found in cows treated with hCG vs. LH during the anovulatory and ovulatory seasons (6.6 vs. 2.8 and 6.3 vs. 3.8 corpora lutea respectively). In addition, dividing the dose of FSH two resulted in greater superovulatory response in wood bison. However, the number of corpora lutea was still lower than expected as compared to cattle using the same two dose method of superovulation (15 corpora lutea; Tribulo et al., 2012). Therefore, in Chapter 6, the effect of the addition of a low dose of eCG at the end of the superstimulation protocol on ovarian response and embryo quality was examined. Although the number of ova/embryos recovered was higher in this study when compared with previous reports in wood bison, no effect of eCG on the number of corpora lutea and embryo quality was found. In Chapters 5 and 6, the effect of exogenous progesterone on embryo quality in wood bison during the anovulatory season was evaluated. We found that progesterone did not improve the number of freezable embryos in either study. In Chapter 7, the effect of lengthening of FSH treatment protocol on superovulatory response and embryo quality during the ovulatory and anovulatory seasons was examined. There was no effect of lengthening the FSH treatment protocol on ovarian response and embryo quality during the anovulatory season. However, embryo quality and ovulation rate were increased by the lengthened treatment protocol during the ovulatory season. Additionally, more freezable embryos (Grades 1 and 2) were obtained during the ovulatory season (1.8 embryos) vs. the anovulatory season (0.3 embryos). Overall, results confirm that superovulation can be performed in wood bison throughout the year, but a higher number of freezable embryos were obtained during the ovulatory season. The final chapter (Chapter 8) focused in the production of disease-free embryos in wood bison. Following superovulation, in vivo-derived wood bison embryos were exposed in vitro to Brucella abortus biovar 1. After incubation, embryos were submitted to the 10-step washing procedures recommended by the IETS to remove the pathogen. When the washing medium contained antibiotics, 100% Brucella-free embryos were obtained. These findings validate the washing procedures for the production of Brucella-free embryos in wood bison.
49

Knowledge, attitudes, and practices of nurses towards hand washing at a selected Psychiatric Hospital in the Western Cape, South Africa

Muhawenimana, Feza January 2020 (has links)
Magister Curationis - MCur / Studies have shown that no great emphasis has been put on hand washing practices in psychiatric health facilities, despite the fact that nosocomial infection outbreaks have been reported for decades. Most studies have focused on hand washing practices among general health personnel; however, little is known about hand washing practices among nurses working at psychiatric hospitals.
50

Hållbarhetsarbeten inom väg- och anläggningsbranschen : en undersökning av certifieringssystemet CEEQUAL

Lohmann, Nils January 2017 (has links)
In this master thesis, the road- and construction industry's and the company Skanska Sverige AB’s views on sustainability and interest in the British certification system CEEQUAL are investigated, and if there is added value with it and in that case what value. This is done through interviews with civil servants in Skanska's road and civil engineering branch and various representatives of the actors that represent Skanska's largest customers in the region of Central Sweden. The material from the interviews is then compared in an analysis in which similarities, differences and patterns are highlighted.   The conclusion of the master thesis is based on the analyzed material, which states that most of the interviewed person are interested in the CEEQUAL certification system, and see added value as quality assurance, structured work practices and proven environmental care, leading to positive publicity. The thesis work also touches on interesting areas such as green washing, municipal limits on project procurement with respect to the Public Procurement Act as well as potential and future impacts in CEEQUAL market. These are areas recommended for further studies.

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