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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.
111

SOIL PHOSPHORUS DYNAMICS UNDER ANNUAL OR SINGLE APPLICATIONS OF ALKALINE TREATED BIOSOLIDS

Shu, Weixi 14 April 2014 (has links)
Land application of biosolids as a soil fertility amendment is an alternative to traditional disposal methods. The influence of annual Alkaline Treated Biosolids (ATB) land application on phosphorus (P) dynamics in acidic soils needs to be better understood for more efficient P management. This study examines plant uptake, plant available, soil total phosphorus (P) content and potential P accumulation as a function of rate and frequency of application of an ATB amended to an agricultural soil over four years. The results suggest that applying high rates of ATB annually can increase the soil pH, Mehlich 3 and water extractable P, and crop P uptake in an acidic agricultural soil. No significant soil P accumulation was observed and P related environmental concerns were limited in this study. Potential soil P accumulation and higher P loss needs to be considered with annual high ATB rates application over a longer period study. / N/A
112

A mineralogical, geochemical and geochronological study of postorogenic carbonatites in the Eden Lake complex, northern Manitoba.

Elliott, Barrett 24 August 2009 (has links)
The first documented carbonatites in Manitoba occur as dykes and pods up to 15 meters in length and several meters in width at Eden Lake hosted in a post-orogenic syenitic complex within the Trans-Hudson Orogen. The carbonatites consist dominantly of calcite with lesser clinopyroxene, feldspar, apatite and titanite. Primary and xenocrystic clinopyroxene have distinct compositions, whereas xenocrystic feldspar has well-developed plagioclase and alanite rims. The whole-rock major- and trace-element composition of the carbonatite is consistent with global averages for calcio-carbonatites. Stable-isotope compositions of calcite indicate an igneous origin; the low δ13C ratios may reflect the influence of subducted sedimentary carbonate. A zircon age of 1815±8 Ma corresponds with the time of emplacement, whereas younger titanite ages reflect local thermal history. Although field relations suggest a genetic link to the host syenites, whole-rock geochemical data is incompatible with immiscibility or crystal fractionation models, suggesting a discrete mantle source for the carbonatite.
113

Adhesion of Epoxy Coating to Steel Reinforcement under Alkaline Conditions

Masoudi, Rana Jr 05 December 2013 (has links)
Epoxy-coated reinforcement was developed in the 1970s and became the primary corrosion protection technique in North America. Throughout the years, ECR has exhibited mixed results, with some regions and jurisdictions reporting good corrosion protection while others reported poor field performance of ECR. It has been established that epoxy coating can lose its adhesion in a wet environment thus providing poor corrosion protection of reinforcing steel. However, limited research has been done on the influence of concrete pore solution on adhesion of epoxy coating to reinforcing steel. This research investigates the effect of high alkali conditions on performance of ECR bars. Based on the test results, it was found that the rate of disbondment increases as the hydroxyl ion concentration increases and presence of high temperature accelerates the disbondment process.
114

Adhesion of Epoxy Coating to Steel Reinforcement under Alkaline Conditions

Masoudi, Rana Jr 05 December 2013 (has links)
Epoxy-coated reinforcement was developed in the 1970s and became the primary corrosion protection technique in North America. Throughout the years, ECR has exhibited mixed results, with some regions and jurisdictions reporting good corrosion protection while others reported poor field performance of ECR. It has been established that epoxy coating can lose its adhesion in a wet environment thus providing poor corrosion protection of reinforcing steel. However, limited research has been done on the influence of concrete pore solution on adhesion of epoxy coating to reinforcing steel. This research investigates the effect of high alkali conditions on performance of ECR bars. Based on the test results, it was found that the rate of disbondment increases as the hydroxyl ion concentration increases and presence of high temperature accelerates the disbondment process.
115

The Effects of Alkaline Peroxide Treatment on Physical and Structural Properties of Low Consistency Refined Paper

Trocki, Pawel Kamil 30 November 2011 (has links)
Physical property data was used to test two hypotheses pertaining to the impact of a chemical pre-treatment on the qualities of low consistency refined pulp. The first objective was to determine whether the addition of a chemical treatment would effectively accelerate the refining process when compared to a regular pulp. This involved the measurement of the physical property data and how it changed with increased refining energy. The second objective was to determine how the chemical treatment affected fibre development during refining, and whether its implementation could result in enhancement of inter-fibre bondability. Theoretical models for the physical properties of paper were used to study the fibre-to-fibre bonding properties of the tested paper samples. Additionally, SEM images were obtained to study the deferences in morphology of the tested pulp samples.
116

The Effects of Alkaline Peroxide Treatment on Physical and Structural Properties of Low Consistency Refined Paper

Trocki, Pawel Kamil 30 November 2011 (has links)
Physical property data was used to test two hypotheses pertaining to the impact of a chemical pre-treatment on the qualities of low consistency refined pulp. The first objective was to determine whether the addition of a chemical treatment would effectively accelerate the refining process when compared to a regular pulp. This involved the measurement of the physical property data and how it changed with increased refining energy. The second objective was to determine how the chemical treatment affected fibre development during refining, and whether its implementation could result in enhancement of inter-fibre bondability. Theoretical models for the physical properties of paper were used to study the fibre-to-fibre bonding properties of the tested paper samples. Additionally, SEM images were obtained to study the deferences in morphology of the tested pulp samples.
117

Effect of Alkaline Pretreatment on Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

Alqaralleh, Rania Mona 27 March 2012 (has links)
The rapid accumulation of municipal solid waste is a significant environmental concern in our rapidly growing world. Due to its low cost, high energy recovery and limited environmental impact anaerobic digestion (AD) is a promising solution for stabilizing the organic fraction of municipal solid waste (OFMSW). Hydrolysis is often the rate-limiting step during AD of wastes with high solid content; this step can be accelerated by pretreatment of waste prior to AD. This thesis presents the results of alkaline pretreatment of OFMSW using NaOH and KOH. Four different pH levels 10, 11, 12 and 13 at two temperatures 23±1°C and 80±1°C were examined to study the effects of the pretreatment on (i) enhancing the solubility of the organic fraction of the waste, and (ii) enhancing the AD process and the biogas production. The effects on solubility were investigated by measuring changes in the soluble COD (SCOD) concentrations of pretreated wastes and the enhanced AD was investigated by measuring volatile solids (VS) destruction, total COD (TCOD) and SCOD removal in addition to biogas and methane production using biochemical methane potential (BMP) assay and semi-continuous laboratory reactor experiments. Pretreatment at pH 13 at 80±1°C demonstrated the maximum solubility for both NaOH and KOH pretreated samples; however the BMP analysis demonstrated that pretreatment at pH 12 at 23±1°C showed the greatest biogas yield relative to the removed VS for both chemicals. Thus pretreatment at pH 12 at 23±1°C using NaOH and KOH were examined using semi-continuous reactors at three different HRTs: 10, 15 and 20 days. Pretreatment demonstrated a significant improvement in the AD performance at SRTs of 10 and 15 days.
118

A comprehensive mechanism for anthraquinone mass transfer in alkaline pulping

Samp, James Christian 05 May 2008 (has links)
A mechanism for the mass transfer of anthraquinone (AQ) into wood during alkaline pulping has been developed. Although the chemistry of action of AQ is well-developed, there has not been much work conducted on its diffusion properties. The discrepancies between different experiments with AQ indicate that something other than the chemistry is at work. Because most of the differences arise from differences in pulping conditions, it is likely that mass transfer is the source of these discrepancies. A model system was therefore developed to explore the mass transfer properties of AQ. It was shown that AQ must be reduced to anthrahydroquinone (AHQ) at the membrane surface before any permeation of a membrane can occur. It was also shown that increasing surface coverage of the membrane through AQ particle size reduction could improve the rate of membrane permeation. The mechanism described by the model system was then tested against pulping data. It was shown that the addition of surfactants increases the pulping efficiency of AQ. This is probably through better dispersion of AQ particles to cover more chip surface area. Bulk reduction effects were also tested, and it was shown that bulk phase reducing agents decrease the efficacy of AQ in pulping. This led to the development of the mechanism for AQ diffusion in alkaline pulping.
119

Numerical evaluation of fourth-order many-body corrections to transition amplitudes for principal transitions in alkali-metal atoms /

Cannon, Caleb C. January 2006 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 45-46). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.
120

Alkaline phosphatase isoenzymes determination and zinc concentrations in human serum, liver and pancreas /

Kulnaree Vorapongpichest. January 1978 (has links) (PDF)
Thesis (M.Sc. (Clinical Pathology))--Mahidol University, 1978.

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