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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.
31

Effect of fractionation on nutritional value of wheat distillers grains for rainbow trout (<i>Oncorhynchus mykiss</i>)

Reveco Urzúa, Felipe Eduardo 21 July 2010
In this study, the nutritional value of wheat distillers grains and the effect of further processing of these products on their nutritional value for rainbow trout were investigated in five experiments. In experiments 1 and 2, wheat distillers grains with solubles (WDDGS) was fractionated using grinding, sieving and elutriation sequentially. Apparent digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), acid ether extract (AEE), ash and amino acids (AA) did not differ between the original WDDGS and the WDDGS protein concentrate (P > 0.05). However, the ADC of crude protein (CP) was significantly higher for WDDGS protein concentrate (88.0 %) than the original WDDGS (84.9 %) (P < 0.05). In experiments 3 and 4, the effect of aqueous fractionation on nutritional composition of wheat wet distillers grains (WWDG) from two local ethanol plants (plant 1 and plant 2) was evaluated. Aqueous fractionation increased levels of CP and GE in the processed WWDG from both plants. Fractionation significantly increased the ADC of DM, GE and AEE (P < 0.05). In contrast, protein digestibility was not influenced by the plant or the processing method (P > 0.10). In experiment 5, a 56 d growth trial was performed to determine the effect feeding the aqueous fractionated WWDG to rainbow trout on growth performance. Rainbow trout (n=22/ tank; body weight 136 g and 3 tanks/ treatment) were fed diets containing 0, 75, 150, 225 and 300 g kg-1 of the processed WWDG from plant 2. There were no significant linear or quadratic relationships between inclusion rate and specific growth rate (SGR), average daily gain (ADG) or feed to gain ratios (feed:gain). However, there was a significant negative linear relationship between inclusion rate and average daily feed intake (ADFI) (P < 0.05). The results of these studies suggest that both dry and aqueous fractionation are suitable methods to produce protein concentrates from wheat distillers grains but that the aqueous fractionation process was more effective in improving nutrient composition and increasing digestibility.
32

Characterization of dissolved organic carbon in prairie surface water using FTIR spectroscopy

Xing, Yanan 13 April 2010 (has links)
Surface water reservoirs in rural areas of the Canadian prairies often have poor water quality due to contamination by dissolved organic carbon (DOC). DOC can activate growth of microorganisms in water distribution systems and form disinfection by-products (DBPs) in water treatment. The presence of microbiological contaminants and DBPs are potentially harmful to human health. Therefore, rapid and simple methods for DOC characterization are needed to evaluate potential water sources and to assist in understanding how best to remove DOC. The first objective of this project was to develop a sample preparation and analysis procedure utilizing Fourier Transform Infrared Spectroscopy (FTIR) to characterize the DOC content of water samples. The second objective was to compare FTIR analysis results for fractionated and un-fractionated water samples to more convention DOC characterization methods (such as UV, SUVA and specific THMFP). The third objective was to demonstrate the application of the procedure to source water assessment and water treatment process evaluation by characterizing the DOC content of several typical treated and un-treated prairie water samples at several locations in Saskatchewan.<p> In the first phase of the study prepared samples of known DOC concentration were separated into six fractions (hydrophobic acid (HPOA), hydrophobic neutral (HPON) and hydrophobic base (HPOB); and hydrophilic acid (HPIA), hydrophilic neutral (HPIN) and hydrophilic base (HPIB)) using resin fractionation techniques. FTIR and conventional UV spectroscopic measurements, DOC concentration, and trihalomethane formation potential (THMFP) measurements were taken on the un-fractionated samples and their fractions. A water matrix interference problem in the FTIR measurements was overcome by depositing a residue of dry solids from the aqueous solution containing the DOC on a flat, organic compound free and non-infrared absorptive gold plated slide before analysis. This simple evaporation procedure developed for concentrating water samples successfully deposited a solid residue for FTIR scanning. Scanning of the solid residue of each sample at multiple locations successfully produced a spectrum of average results suitable for interpretation.<p> Each organic fraction separated from the prepared samples of known DOC was then assessed using FTIR analysis. Comparison of the spectra from the resin adsorption fractions gave an indication of the relationship between functional groups and the hydrophobic/hydrophilic nature of the DOC. The results suggest that the hydrophobic fractions contain more aromatic functional groups. This demonstrates that the FTIR spectra can provide information regarding the hydrophobic/hydrophilic nature of the DOC as an alternative to the resin separation procedure. The sample preparation and FTIR analysis procedure was then used to characterize the DOC content of source and treated waters at several locations within Saskatchewan. The results of these initial investigations indicate the method can effectively identify the major organic functional groups present in source waters and the changes in the major functional groups that occur as the water is subjected to water treatment unit operations and processes. Further, the presence of several key functional groups is related to an increase in THMFP.
33

Effect of fractionation on nutritional value of wheat distillers grains for rainbow trout (<i>Oncorhynchus mykiss</i>)

Reveco Urzúa, Felipe Eduardo 21 July 2010 (has links)
In this study, the nutritional value of wheat distillers grains and the effect of further processing of these products on their nutritional value for rainbow trout were investigated in five experiments. In experiments 1 and 2, wheat distillers grains with solubles (WDDGS) was fractionated using grinding, sieving and elutriation sequentially. Apparent digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), acid ether extract (AEE), ash and amino acids (AA) did not differ between the original WDDGS and the WDDGS protein concentrate (P > 0.05). However, the ADC of crude protein (CP) was significantly higher for WDDGS protein concentrate (88.0 %) than the original WDDGS (84.9 %) (P < 0.05). In experiments 3 and 4, the effect of aqueous fractionation on nutritional composition of wheat wet distillers grains (WWDG) from two local ethanol plants (plant 1 and plant 2) was evaluated. Aqueous fractionation increased levels of CP and GE in the processed WWDG from both plants. Fractionation significantly increased the ADC of DM, GE and AEE (P < 0.05). In contrast, protein digestibility was not influenced by the plant or the processing method (P > 0.10). In experiment 5, a 56 d growth trial was performed to determine the effect feeding the aqueous fractionated WWDG to rainbow trout on growth performance. Rainbow trout (n=22/ tank; body weight 136 g and 3 tanks/ treatment) were fed diets containing 0, 75, 150, 225 and 300 g kg-1 of the processed WWDG from plant 2. There were no significant linear or quadratic relationships between inclusion rate and specific growth rate (SGR), average daily gain (ADG) or feed to gain ratios (feed:gain). However, there was a significant negative linear relationship between inclusion rate and average daily feed intake (ADFI) (P < 0.05). The results of these studies suggest that both dry and aqueous fractionation are suitable methods to produce protein concentrates from wheat distillers grains but that the aqueous fractionation process was more effective in improving nutrient composition and increasing digestibility.
34

The preparation of aspen holocellulose and a chemical study of its fractions.

Thomas, Berwyn Brainerd 01 January 1944 (has links)
No description available.
35

The influence of cooking and bleaching upon the chain length distribution of the carbohydrate fraction in pulp wood

Atchison, Joseph Edward 01 January 1942 (has links)
No description available.
36

Mechanistic and experimental investigations of pulsed electric field flow fractionation micro device and its applications for nanoparticle and biomolecule separation /

Lao, Ieng Kin. January 2004 (has links)
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Accompanying CD-ROM contains supporting information on avi formated video clips. Includes bibliographical references (leaves 172-183). Also available in electronic version. Access restricted to campus users.
37

A rapid method for the preparation of lung cell fractions enriched in alveolar type II pneumocytes

Lafranconi, Walter Mark January 1981 (has links)
No description available.
38

Hypofractionated conformal stereotactic radiotherapy in the treatment of AVMs and cerebral metastases /

Lindvall, Peter, January 2006 (has links)
Diss. (sammanfattning) Umeå : Univ., 2006. / Härtill 5 uppsatser.
39

Formas de fósforo, substâncias húmicas e nitrogênio inorgânico em áreas da Amazônia ocidental / Phosphorus fractions, humic substances and inorganic nitrogen in area of western Amazon

Moline, Ederlon Flávio da Veiga [UNESP] 29 February 2016 (has links)
Submitted by EDERLON FLÁVIO DA VEIGA MOLINE null (ederlon_flavio@hotmail.com) on 2016-03-24T16:17:40Z No. of bitstreams: 1 Tese_Ederlon_Flavio_da_Veiga_Moline.pdf: 1182239 bytes, checksum: 89607a2b0f12ad7d974e40bb2640fc75 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-24T19:37:33Z (GMT) No. of bitstreams: 1 moline_efv_dr_jabo.pdf: 1182239 bytes, checksum: 89607a2b0f12ad7d974e40bb2640fc75 (MD5) / Made available in DSpace on 2016-03-24T19:37:33Z (GMT). No. of bitstreams: 1 moline_efv_dr_jabo.pdf: 1182239 bytes, checksum: 89607a2b0f12ad7d974e40bb2640fc75 (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM) / A abertura de áreas agrícolas na Amazônia altera a dinâmica do ambiente e consequentemente os atributos químicos do solo. O objetivo dessa pesquisa foi avaliar o efeito da transformação de áreas de florestas em áreas de cultivo agrícola quantificando as formas de P, substâncias húmicas e N inorgânico na Amazônia Ocidental. Foram coletadas amostras de solos em Latossolo Amarelo sob mata nativa, pastagem, citrus, e em áreas com horizonte A antrópico, citrus em Terra Preta de Índio e citrus em Terra Mulata nas profundidades de 0 – 5, 5 – 10 e 10 – 20 cm no município de Manacapuru, Amazonas e realizado o fracionamento de P, substâncias húmicas e N inorgânico. A área de mata nativa apresentou os menores teores de formas de P quando comparado aos demais ambientes que aumentaram seus teores após a derrubada da floresta. A área de Terra Preta de Índio foi a área que apresentou as maiores médias em todas as formas de P diferenciando dos demais solos. Entre as formas de P, a fração não-lábil foi a mais presente em todas as áreas e a P lábil, a menor, concentradas na camada de 0 – 5 cm. As substâncias húmicas foram predominantes nas áreas em forma de humina na camada superficial, seguido de ácido húmico e ácido fúlvico. A relação AH/AF foi considerada adequada nas áreas de mata nativa e cultivo de citrus. A presença de N na forma inorgânica de N-NH4+ e N-NO3- corresponderam a pequena parte do N total do solo sendo a primeira forma predominante em todas as áreas, e em Terra Preta de Índio os valores foram equilibrados proporcionalmente. A área de Terra Preta de Índio apresentou menor efeito negativo na transformação da área de floresta e uso em cultivo agrícola quando comparado a Terra Mulata, cultivo de citrus, pastagem e mata nativa, verificando nessa última área a melhor estabilidade dos atributos avaliados e melhor qualidade do solo. / The transformation of agricultural areas in the Amazon changes the dynamics of the environment and consequently the soil chemical properties. The purpose of this study was to evaluate the effect of conversion of forest areas into areas of agriculture quantifying P fractions, humic substances and inorganic N in the Western Amazon. Soil samples were collected in Oxisol under native forest, pasture, citrus, and in areas with anthropogenic A horizon, citrus in Terra Preta de Indio and citrus in Terra Mulata in the depths 0-5, 5-10 and 10-20 cm in the city of Manacapuru, Amazonas and held phosphorus fractionation, humic substances and inorganic nitrogen. The native forest area had the lowest concentrations of P fractions when compared to other environments that increased their levels after forest clearing. The area of Terra Preta de Índio was the area that received the highest average in all P pools differing from other soils. Among the P pools, the non-labile fraction was the most widespread in all areas and P labile concentrated in the lower layer of 0-5 cm. The humic substances were prevalent in areas form the surface layer humin, humic acid and followed by fulvic acid. The ratio HA/AF was considered appropriate in the areas of native forest and citrus cultivation. The presence of inorganic N as N-NH4+ and N-NO3- corresponding to small part of the total N soil predominant form being the first in all areas, and Terra Preta de Índio values were similar. The area of Terra Preta de Índio showed less negative effect on the transformation of forest area and use in agricultural cultivation compared to Terra Mulata, citrus cultivation, pasture and native forest, checking in this last area the better stability of the evaluated attributes and best quality from soil.
40

Uranium Isotope Fractionation During Coprecipitation with Aragonite and Calcite

January 2015 (has links)
abstract: Natural variations in 238U/235U of marine carbonates might provide a useful way of constraining redox conditions of ancient environments. In order to evaluate the reliability of this proxy, we conducted aragonite and calcite coprecipitation experiments at pH ~7.5 and ~ 8.5 to study possible U isotope fractionation during incorporation into these minerals. Small but significant U isotope fractionation was observed in aragonite experiments at pH ~ 8.5, with heavier U in the solid phase. 238U/235U of dissolved U in these experiments can be fit by Rayleigh fractionation curves with fractionation factors of 1.00007+0.00002/-0.00003, 1.00005 ± 0.00001, and 1.00003 ± 0.00001. In contrast, no resolvable U isotope fractionation was observed in an aragonite experiment at pH ~7.5 or in calcite experiments at either pH. Equilibrium isotope fractionation among different aqueous U species is the most likely explanation for these findings. Certain charged U species are preferentially incorporated into calcium carbonate relative to the uncharged U species Ca2UO2(CO3)3(aq), which we hypothesize has a lighter equilibrium U isotope composition than most of the charged species. According to this hypothesis, the magnitude of U isotope fractionation should scale with the fraction of dissolved U that is present as Ca2UO2(CO3)3 (aq). This expectation is confirmed by equilibrium speciation modeling of our experiments. Theoretical calculation of the U isotope fractionation factors between different U species could further test this hypothesis and our proposed fractionation mechanism. These findings suggest that U isotope variations in ancient carbonates could be controlled by changes in the aqueous speciation of seawater U, particularly changes in seawater pH, PCO2, [Ca], or [Mg] concentrations. In general, these effects are likely to be small (<0.13 ‰), but are nevertheless potentially significant because of the small natural range of variation of 238U/235U. / Dissertation/Thesis / Masters Thesis Chemistry 2015

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