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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.
121

Separation and coalescence phenomena in three phase systems

Smith, Peter Graham. January 1984 (has links)
The behavior of model three phase solid/liquid/liquid systems has been studied in the external fields of shear or gravity. Observations of the deformation and break-up of solid-liquid clusters in a simple shear field has led to an investigation of various aspects of separation and coalescence phenomena: the interaction of solid particles and drops in simple shear, film thinning processes, the thermodynamics of engulfment and solid-liquid separation by the external fields. / A microrheological approach was used to determine which parameters are important to the behavior of these systems in simple shear. Among the most important were found to be the liquid/liquid interfacial tension, the incidence of three phase contact and/or the wettability of the solid surface. / The importance of these paramters was also investigated in the formation and stability of sphere-drop systems in a gravitational field, and the detachment of the liquid drop by surface and gravitational forces. / Extensions to existing theory have been made to include gravitational effects in the thinning of a liquid film which forms around a sphere. Finally, an asymptotic solution to the Laplace equation of capillarity has been developed which may be applied to various axisymmetric liquid/fluid interfaces not too far from spherical shape. / The findings in this thesis are highly relevant to various industrial processes (such as in the production of oil, minerals, paper, etc.) where three phase systems are encountered.
122

Extraction, partial purification and characterization of the lipase fraction from the viscera of grey mullet (Mugil cephalus)

Aryee, Alberta Naa Ayeley. January 2005 (has links)
Lipase was partially purified from the viscera of grey mullet ( Mugil cephalus) by ammonium sulfate fractionation, simultaneous desalting, and concentration via ultrafiltration and then affinity chromatography on EAH-Sepharose 4B. The partially purified extract was characterized using p-nitrophenyl palmitate (rho-NPP) as substrate. Grey mullet lipase was active within the pH range of 7-10, with an optimum pH of 8.0, and was stable from pH 4-10. The enzyme was active within the temperature range of 20°C and 60°C, and exhibited an optimum for the hydrolysis of rho-NPP at 50°C. The enzyme was stable between 10-50°C, beyond which it lost activity progressively. At 50°C there was ca. 50% residual activity after 60 min incubation. However at 60°C, there was 22%, 20% and 0% remaining activity after 10, 30 and 60 min incubation respectively. Based on the temperature activity data, the activation energy for the hydrolysis of rho-NPP was calculated as 1.94 kcal/mol (8.15 kJ/mol). / The rho-nitrophenyl esters of medium to long chain fatty acid (C10-C16) served as good substrates with the order of ease of hydrolysis as; rho-NP-palmitate > rho-NP-myristate > rho-NP-caprate > rho-NP-caproate > rho-NP-butyrate > rho-NP-acetate. The Km' and Vmax for the hydrolysis of rho-NPP were 0.22 mM and 20 mumol min-1 mg-1 , respectively. The hydrolytic activity of the lipase was enhanced by Mg2+, Mn2+, NaN3, and EDTA, but strongly inhibited by Hg2+, and Cu2+. PMSF (1 mM), Ca2+ (1 mM and 10 mM) had no effect on grey mullet lipase activity. Lower concentrations (25-10% v/v) of water-miscible organic solvents (dimethyl sulfoxide, dimethyl formamide, iso-propanol, and methanol) had negligible effect on the activity of the lipase while higher concentrations (>50% v/v) completely inhibited the enzyme. The grey mullet lipase was remarkably stable in water-immiscible organic solvents (benzene, toluene, hexane, heptane, and isooctane). The water-immiscible solvents also activated the enzyme with hexane giving the most activation. Lower concentrations of trihydroxylated bile salts (sodium taurocholate, and sodium cholate) were more potent activators than the dihydroxylated bile salt (sodium deoxycholate). Sodium dodecyl sulfate at 1 mM, and Tween 80RTM at 1% had 6% and 12% stimulatory effect on the activity of the enzyme respectively, while 1% and 0.5% Triton RTM X-100 caused 67% and 40% inhibition, respectively.
123

Production of Single-Cell-Protein from waste pasta products by Endomycopsis fibuligera.

Lachance, Marc-André. January 1973 (has links)
No description available.
124

Scavenging iron ore tailings with the Reichert cone

Nudo, Vince January 1987 (has links)
No description available.
125

Isolation and characterization of proteins from defatted flaxseed meal

El-Ramahi, Razan S. January 2003 (has links)
Interest in flaxseed and products derived from flaxseed has increased considerably in the past decade. In the development of nutraceutical foods, several flaxseed components including lignans and alpha-linolenic acid, have been recognized to have health benefits. There are many patents and health claims to these components; however, relatively little research and information is found on flaxseed proteins. The objective of the present study was to isolate and characterize flaxseed proteins from defatted flaxseed meal. / Proteins were extracted from defatted flaxseed meal with NaOH. NaCl and NaCl/Papain. Protein solubility with these extractants ranged from 18 to 25%. Proteins were precipitated from the extracts using one or more of the following precipitation techniques; isoelectric precipitation (IP) gave yields and protein contents ranging between 22--25% and 67--73% respectively. Co-precipitation with soy and whey proteins gave yields of 26.95 and 35.78% respectively for a NaOH extract. Chemical hydrolysis of flaxseed meal with NaOH, NaCl and NaCl/Papain extraction and IP increased protein solubilization (35--43%) and protein yields (19--37%). / Proteins in the extracts and isolates were characterized by polyacrylamide gel electrophoresis (PAGE). Proteins extracted with NaOH and NaCl gave two bands by native-PAGE with molecular weights (MW) of 320 and 514KDa; proteins extracted with NaCl/Papain gave a single band at 188KDa. SDS-PAGE of isolates extracted with NaOH, NaCl and NaCl/Papain gave subunits with MW ranging from 6.5 to 56KDa. The major fractions isolated from NaOH-IP by RP-HPLC showed subunits with MW ranging from 6.5 to 40.1KDa by SDS-PAGE and 5.9 to 42.5KDa by ESI-MS. Subunits characterized by ESI-MS have not been reported previously in the literature.
126

Separation of ethylene and ethane by adsorption on titanosilicate

Shi, Meng 06 1900 (has links)
The energy costs associated with ethane-ethylene separation could be significantly reduced by the development of alternatives to cryodistillation. This work examined ethylene recovery by equilibrium adsorption on two types of titanosilicate molecular sieve adsorbents, Na-ETS-10 and Zn-RPZ. A practical adsorptive separation of industrial process gas, with a measured binary bed selectivity for ethylene over ethane of approximately 5 at 25C and 1 atm, was demonstrated using Na-ETS-10 as the adsorbent. The effects of different binder systems and separation flow rates on the mass transfer properties of Na-ETS-10 were examined in order to optimize the separation. High pressure and low temperature, similar to the working conditions in ethylene production plants, were found to increase the separation factor for these materials. Thermal, steam and microwave desorption methods were compared, and microwave desorption was determined to be the most efficient option for ethylene/ethane desorption and Na-ETS-10 regeneration. / Chemical Engineering
127

Permeability theory for polydispersed colloidal cakes and analysis of membrane bioreactor (MBR) models

Ng, Aileen January 2006 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 89-93). / viii, 93 leaves, bound ill. 29 cm
128

Improving galena/sphalerite selectivity at Hellyer :

Morey, Michael S. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 1998
129

Toward a biblical view of separation and cooperation among believers

Huffman, Dale T. January 1988 (has links)
Thesis (Th. M.)--Grace Theological Seminary, 1988. / Abstract. Includes bibliographical references (leaves 110-116).
130

The practice of secondary separation in light of 2 Thess. 3:6-15

Wesley, Robert W. January 1982 (has links)
Thesis (Th. M.)--Capital Bible Seminary, 1982. / Typescript. Includes bibliographical references (leaves 61-67).

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