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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.
91

ANALYSIS OF THE PILE LOAD TESTS AT THE US 68/KY 80 BRIDGE OVER KENTUCKY LAKE

Lawson, Edward 01 January 2019 (has links)
Large diameter piles are widely used as foundations to support buildings, bridges, and other structures. As a result, it is critical for the field to have an optimized approach for quality control and efficiency purposes to measure the suggested number of load tests and the required measured capacities driven piles. In this thesis, an analysis of a load test program designed for proposed bridge replacements at Kentucky Lake is performed. It includes a detailed site exploration study with in-situ and laboratory testing. The pile load test program included monitoring of a steel H-pile and steel open ended pipe pile during driving and static loading. The pile load test program included static and dynamic testing at both pile testing locations. Predictions of both pile capacities were estimated using commonly applied failure criterion, and a load transfer analysis was carried out on the dynamic and static test data for both piles. The dynamic tests were then compared to the measured data from the static test to examine the accuracy. This thesis concludes by constructing t-z and q-z curves and comparing the load transfer analyses of the static and dynamic tests.
92

THE EFFECTS OF LONG-TERM DEAFNESS ON DENSITY AND DIAMETER OF DENDRITIC SPINES ON PYRAMIDAL NEURONS IN THE DORSAL ZONE OF THE FELINE AUDITORY CORTEX

Bauer, Rachel J 01 January 2019 (has links)
Neuroplasticity has been researched in many different ways, from the growing neonatal brain to neural responses to trauma and injury. According to recent research, neuroplasticity is also prevalent in the ability of the brain to repurpose areas that are not of use, like in the case of a loss of a sense. Specifically, behavioral studies have shown that deaf humans (Bavalier and Neville, 2002) and cats have increased visual ability, and that different areas of the auditory cortex enhance specific kinds of sight. One such behavioral test demonstrated that the dorsal zone (DZ) of the auditory cortex enhances sensitivity to visual motion through cross-modal plasticity (Lomber et. al., 2010). Current research seeks to examine the anatomical structures responsible for these changes through analysis of excitatory neuron dendritic spine density and spine head diameter. This present study focuses on the examination of DZ neuron spine density, distribution, and size in deaf and hearing cats to corroborate the visual changes seen in behavioral studies. Using Golgi-stained tissue and light microscopy, our results showed a decrease in overall spine density but slight increase in spine head diameter in deaf cats compared to hearing cats. These results, along with several other studies, support multiple theories on how cross-modal reorganization of the auditory cortex occurs after deafening
93

Network Flow Models for Designing Diameter-Constrained Minimum Spanning and Steiner Trees

Gouveia, Luis, Magnanti, Thomas L. 08 1900 (has links)
The Diameter-Constrained Minimum Spanning Tree Problem seeks a least cost spanning tree subject to a (diameter) bound imposed on the number of edges in the tree between any node pair. A traditional multicommodity flow model with a commodity for every pair of nodes was unable to solve a 20-node and 100-edge problem after one week of computation. We formulate the problem as a directed tree from a selected central node or a selected central edge. Our model simultaneously finds a central node or a central edge and uses it as the source for the commodities in a directed multicommodity flow model with hop constraints. The new model has been able to solve the 20-node, 100-edge instance to optimality after less than four seconds. We also present model enhancements when the diameter bound is odd (these situations are more difficult). We show that the linear programming relaxation of the best formulations discussed in this paper always give an optimal integer solution for two special, polynomially-solvable cases of the problem. We also examine the Diameter Constrained Minimum Steiner Tree problem. We present computational experience in solving problem instances with up to 100 nodes and 1000 edges. The largest model contains more than 250,000 integer variables and more than 125,000 constraints.
94

Behavior of Precast Bridge Deck Joints with Small Bend Diameter U-Bars

Chapman, Cheryl Elizabeth 01 August 2010 (has links)
The Interstate Highway System plays a vital role in our economic development by providing a continuous corridor for transporting goods and services. Currently, there is a need for repair and expansion of the existing highways, which include all bridges along its path. Because of the high demand for the highway system, repair and expansion must occur rapidly and efficiently. In recent years, precast bridge deck systems have become an efficient way to reduce construction time during repair. This thesis presents the experimental research of the behavior of the U-Bar joint detail used in precast bridge deck systems. This detail consists of staggered reinforcement extending beyond the precast deck portion into the joint. Six specimens utilizing the U-Bar detail were constructed and tested. Three specimens were tested in flexure to simulate the forces applied in a longitudinal deck joint, while three specimens were tested in pure tension to simulate the forces experienced in a transverse deck joint located over an interior pier. A tight 180° bend at 3db was desired in order to minimize the thickness of the deck. To achieve this tight bend, deformed wire reinforcement was chosen for the U-Bar detail due to the favorable material properties of deformed wire reinforcement. The purpose of the testing was to determine if the joint details could generate a precast deck system that could emulate the monolithic cast-in-place deck systems already in use. For monolithic behavior in a precast deck system, the joints must be able transfer shear, tension and moments. In this research, the joint overlap length was the most dominant variable, and should not be less than 152.4 mm (6”). The precast bridge deck joint should consist of high strength concrete with f’c of at least 68.9 MPa (10 ksi). The longitudinal reinforcement spacing should be no greater than 152.4 mm (6”).
95

Lymphatic Fluid Mechanics: An In Situ and Computational Analysis of Lymph Flow

Rahbar, Elaheh 2011 August 1900 (has links)
The lymphatic system is an extensive vascular network responsible for the transport of fluid, immune cells, proteins and lipids. It is composed of thin-walled vessels, valves, nodes and ducts, which work together to collect fluid, approximately 4 L/day, from the interstitium transporting it back to the systemic network via the great veins. The failure to transport lymph fluid results in a number of disorders and diseases. Lymphedema, for example, is a pathology characterized by the retention of fluid in limbs creating extreme discomfort, reduced mobility and impaired immunity. In general, there are two types of edema: primary edema, being those cases that are inherited (i.e. genetic predisposition), and secondary edema, which develop post-trauma or injury of the lymphatic vessels. With the onset of breast cancer and radiation therapies, the prevalence of secondary edema is on the rise. Clinical studies have shown that up to 80% of women who undergo nodal-dissection surgery develop lymphedema in their arms within 3-5 years of the surgery. Unfortunately, there is no cure or remedy for lymphedema stemming from our lack of understanding of the lymphatic system. The goal of this study was to evaluate lymph flow both experimentally and analytically to better understand the mechanisms regulating lymph transport. In particular we investigated the effects of pressure, volume loads and valve resistance on lymphatic function in the rat mesentery. Our experimental results were then used to develop computational and constitutive models to emulate the dynamic behavior of lymph transport. Collectively, the data illustrate the mechanics of lymphatic contractility and lymph flow. In particular, lymph flow and pumping significantly increased post edemagenic stress in the rat model. Furthermore, lymphangions exhibited highly nonlinear pressure-diameter responses at low pressures between 3-5 cmH2O. These experimental results strongly suggest the regulation of lymph flow via changes in pressure, shear stress and vessel diameter. Furthermore, the computational and constitutive models from this study provide great insight into lymphatic function characterizing the mechanical properties of a single pumping unit (i.e. lymphangion). These models will serve as valuable tools to further lymphatic research.
96

Effect of pore diameter variation of FeW/SBA-15 supported catalysts on hydrotreating of heavy gas oil from Athabasca bitumen

Boahene, Philip Effah 24 June 2011
The pore diameter of a catalyst support controls the diffusion of reactant molecules to the catalytic active sites; thus, affecting the rates and conversions of the hydrotreating reactions. Desirable textural properties of SBA-15 makes it a potential alternative to the conventionally used γ-Al2O3 support due to the fact that its pore size can be manipulated via controlling the synthesis parameters, while maintaining relatively high surface area. Larger pore diameter SBA-15 supports may facilitate the diffusion of bulky molecules as that of the asphaltenes present in the heavy petroleum fractions, making it a potential catalyst support for hydrotreating operations. Considering the very sour nature of Canadas bitumen with high sulfur contents in the range of 2-6 wt %, the appreciably high sulfur contents particularly present in Athabasca derived heavy gas oils (about 4 wt % sulfur), the rising demand for cleaner fuels, and also the increasing stringency on environmental standards, the need for novel and improved hydrotreating catalysts cannot be overemphasized. By varying the molar ratio of hexane to ammonium fluoride, the pore channels of SBA-15 could be varied. Controlling the pore diameter of these supports via micelle swelling facilitated the production of larger pore diameter SBA-15-supported catalysts. In this project, four mesoporous silica SBA-15 catalyst supports with pore diameters in the range of 5-20 nm were synthesized in the preliminary phase using hexane as the micelle swelling agent and subsequently utilized for the loading of 2 wt.% Fe and 15 wt.% W catalyst metals, respectively. The hexagonal mesoscopic structure of these materials were characterized using powder small-angle X-ray scattering (SAXS), N2 adsorption-desorption isotherms, TEM and SEM images. Powder XRD analysis evidenced inhomogeneous metal dispersion on the largest pore diameter catalyst. An optimum pore diameter of 10 nm was found for Cat-B and subsequently used to obtain the optimum Fe and W loadings required to achieve the best hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. The optimum catalyst was found to be Cat-H with metal loadings of 3 wt.% Fe and 30 wt.% W. At these loadings and temperatures of 375°C, 388°C, and 400°C, HDS activities of 53.4%, 64.1%, and 73.3% with corresponding HDN activities of 21.9%, 26.2%, and 38.3%, respectively, were recorded. Catalytic performance evaluations conducted on equal mass loading using a reference commercial γ-Al2O3-supported FeW catalyst offered HDS activities of 69.3%, 80.4%, and 89.1%, with corresponding HDN activities of 16.4%, 32.4%, and 49.3% at the same temperatures studied. However, no significant changes in HDS and HDN activities were observed for similar evaluations on volume percent metals loading basis. Kinetic studies performed with the optimum FeW/SBA-15 catalyst suggested activation energies of 147.2 and 150.6 kJ/mol for HDS and HDN, respectively, by the Langmuir-Hinshelwoods model. Similar results were predicted by the Power Law and Multi-parameter models for HDS (129.6 and 126.7 kJ/mol, respectively), which does not conclusively make the latter model clearly stand out as the best. Data fitting by the Power Law suggested reaction orders of 2 and 1.5 for HDS and HDN, which seem to be consistent for the hydrotreatment of heavy gas oil. Finally, a long-term deactivation study spanning a period of 60 days time-on-stream showed the optimum catalyst to be stable under hydrotreating experiments conducted in a downward flow micro-trickle bed reactor at temperature, pressure, liquid hourly space velocity (LHSV), and gas/oil ratio of 375400˚C, 8.8 MPa, 1h-1, and 600 mL/mL (at STP), respectively.
97

Performance Comparison of Large Diameter Residential Drinking Water Wells

Javor, Paul January 2010 (has links)
Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.
98

Performance Comparison of Large Diameter Residential Drinking Water Wells

Javor, Paul January 2010 (has links)
Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.
99

Performance of Large Diameter Residential Drinking Water Wells - Biofilm Growth: Laboratory and Field Testing

Ruiz Salazar, Hector Fabio 21 November 2011 (has links)
In the first phase of this project three enhanced large diameter (> 60 cm) residential wells were constructed at a study site in Lindsay, Ontario. Two wells were constructed using concrete tile casing while the other well was constructed using galvanized steel casing. Javor (2010) evaluated various aspects of drinking water well construction and design to determine the susceptibility of residential large diameter drinking water wells to surface water and airborne contamination. One of the purposes of these new installations was to remove the uncertainty with respect to construction methods, age and maintenance that is characteristic of residential drinking water well performance studies. Javor (2010) conducted a field and laboratory study to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells. These experiments were also used to determine whether one design was more prone to atmospheric and/or surface water contamination than another. During the second phase of this project routine monitoring was continued and data pertinent to assess the performance of the test wells were collected using the same instrumentation. This routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes extracted from the test wells. In addition to the routine monitoring, a ground penetrating radar (GPR) survey was performed in October 2010 to complement the previous data collected during February 2010. Smoke tracer tests were performed under non-frozen and frozen conditions to re-assess the potential pathways of contaminants between the atmosphere and the interior of the test wells. Bacteriological indicators and high concentrations of two dissolved ions were detected in all test and monitoring wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with similar pathways observed in the winter and the summer. GPR surveys indicated that the bentonite slurry annular sealant was the most homogeneous media. A baseline characterization of the microbial nature of the biofilm performed in three of the test wells (CTH1, ETH1 and ETH3) indicated that the sessile bacteria are more metabolically diverse than suspended bacteria, and that this diversity is even higher in the concrete cased wells. Biofilm characterization performed on concrete, fibreglass and galvanized steel coupons incubated in two of the test wells (concrete and galvanized steel) showed that bacteria in the concrete cased wells barely colonized on fiberglass and galvanized steel, while bacteria in the galvanized steel cased well did not have difficulty colonizing on any of the casing materials. The results of the biofilm cleaning study indicated that the use of pressure washing combined with chlorination effectively removed biofilm grown on galvanized steel and fibreglass casing materials. This study investigated various factors that could affect the performance of large diameter drinking water wells. Since the test wells used in this study were under the direct influence of surface water a comparison between the various annular sealants was problematic. However, the three enhanced test wells outperformed the conventional test well. The observations from the smoke tracer tests performed under non-frozen and frozen conditions indicate that the Poly-Lok lid seam is the most prevalent pathway for airborne contaminants to enter a well. Fibreglass may be the preferred choice for large diameter well casing material since fibreglass is corrosion resistant, lightweight, easy to install, has a high strength to weight ratio, and a greater degree of biofilm was able to be removed from fibreglass casing material than from galvanized steel casing material.
100

Effect of pore diameter variation of FeW/SBA-15 supported catalysts on hydrotreating of heavy gas oil from Athabasca bitumen

Boahene, Philip Effah 24 June 2011 (has links)
The pore diameter of a catalyst support controls the diffusion of reactant molecules to the catalytic active sites; thus, affecting the rates and conversions of the hydrotreating reactions. Desirable textural properties of SBA-15 makes it a potential alternative to the conventionally used γ-Al2O3 support due to the fact that its pore size can be manipulated via controlling the synthesis parameters, while maintaining relatively high surface area. Larger pore diameter SBA-15 supports may facilitate the diffusion of bulky molecules as that of the asphaltenes present in the heavy petroleum fractions, making it a potential catalyst support for hydrotreating operations. Considering the very sour nature of Canadas bitumen with high sulfur contents in the range of 2-6 wt %, the appreciably high sulfur contents particularly present in Athabasca derived heavy gas oils (about 4 wt % sulfur), the rising demand for cleaner fuels, and also the increasing stringency on environmental standards, the need for novel and improved hydrotreating catalysts cannot be overemphasized. By varying the molar ratio of hexane to ammonium fluoride, the pore channels of SBA-15 could be varied. Controlling the pore diameter of these supports via micelle swelling facilitated the production of larger pore diameter SBA-15-supported catalysts. In this project, four mesoporous silica SBA-15 catalyst supports with pore diameters in the range of 5-20 nm were synthesized in the preliminary phase using hexane as the micelle swelling agent and subsequently utilized for the loading of 2 wt.% Fe and 15 wt.% W catalyst metals, respectively. The hexagonal mesoscopic structure of these materials were characterized using powder small-angle X-ray scattering (SAXS), N2 adsorption-desorption isotherms, TEM and SEM images. Powder XRD analysis evidenced inhomogeneous metal dispersion on the largest pore diameter catalyst. An optimum pore diameter of 10 nm was found for Cat-B and subsequently used to obtain the optimum Fe and W loadings required to achieve the best hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. The optimum catalyst was found to be Cat-H with metal loadings of 3 wt.% Fe and 30 wt.% W. At these loadings and temperatures of 375°C, 388°C, and 400°C, HDS activities of 53.4%, 64.1%, and 73.3% with corresponding HDN activities of 21.9%, 26.2%, and 38.3%, respectively, were recorded. Catalytic performance evaluations conducted on equal mass loading using a reference commercial γ-Al2O3-supported FeW catalyst offered HDS activities of 69.3%, 80.4%, and 89.1%, with corresponding HDN activities of 16.4%, 32.4%, and 49.3% at the same temperatures studied. However, no significant changes in HDS and HDN activities were observed for similar evaluations on volume percent metals loading basis. Kinetic studies performed with the optimum FeW/SBA-15 catalyst suggested activation energies of 147.2 and 150.6 kJ/mol for HDS and HDN, respectively, by the Langmuir-Hinshelwoods model. Similar results were predicted by the Power Law and Multi-parameter models for HDS (129.6 and 126.7 kJ/mol, respectively), which does not conclusively make the latter model clearly stand out as the best. Data fitting by the Power Law suggested reaction orders of 2 and 1.5 for HDS and HDN, which seem to be consistent for the hydrotreatment of heavy gas oil. Finally, a long-term deactivation study spanning a period of 60 days time-on-stream showed the optimum catalyst to be stable under hydrotreating experiments conducted in a downward flow micro-trickle bed reactor at temperature, pressure, liquid hourly space velocity (LHSV), and gas/oil ratio of 375400˚C, 8.8 MPa, 1h-1, and 600 mL/mL (at STP), respectively.

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