The present work consists of two parts: experimental study of natural ventilation in a model room and the flow associated with a source-sink pair. The first part describes the natural ventilation of a model room of size 300mmx 300mm x 300mm with water as the fluid medium. It is insulated by air gaps on the four sides and at the top. A constant heat flux of 3148W/m2 has been maintained on the bottom surface of the room. This ‘room’ is surrounded by a large exterior tank containing water. The changes in temperature of the bottom, the interior and the exterior have been measured using T-type thermocouples. There are three openings each on two opposing sides of the model room. For any experiment, only one opening on each side is kept open. Fluid enters or leaves these openings and the flow is driven entirely by buoyancy forces. Three configurations have been studied: (1) The bottom opening at the inlet side and the top opening at the outlet side are open, (2) the bottom opening at the inlet side and the middle opening at the outlet side are open, and (3) the middle opening at the inlet side and the top opening at the outlet side are open. Shadowgraph technique is used for visualization. The buoyancy causes flow to enter through the bottom opening and leave through the top opening. At the openings, buoyant jets are observed and which have higher or lower relative densities. The buoyant jet at the inlet interacts with the plumes on the heated bottom plate. From these visualizations, it appears that free convection at bottom plate will be affected by the buoyant jets at the openings and the degree to which it is affected depends on the position and size of openings and distance between inlet and outlet. The flow rate due to the natural ventilation depends on the bottom surface heat flux and the height difference between the openings. The temperatures of the floor, the interior and the exterior are calculated using a simple mathematical model (Hunt and Linden [1999]). The mathematical model assumes well mixed conditions within the room and accounts for losses at the openings. The values of temperatures obtained in the experiments are reasonably well predicted by the mathematical model. The second part of the work is concerned with the interaction of a source -sink pair. The source consists of fluid issuing out of a nozzle in the form of a jet and the sink is a pipe that is kept some distance from the source pipe. Such source -sink pairs are observed in many situations including data centers, and collection of fresh water from a large reservoir that has also a discharge of pollutants. The main parameters of the problem are source and sink flow rates, the axial and lateral separations of the source and sink, and the angle between the axes of source and sink. Of concern is the percentage of source fluid that enters the sink as a function of these parameters. The experiments have been carried in a large glass water tank. The source nozzle diameter is 6mm and the sink pipe diameter is either 10mm or 20mm. The horizontal and vertical separations and angles between these source and sink pipes are adjustable. The Reynolds numbers of the source jet is about 3200. Experiments were done with the sink flow rate equal to, lower or higher than the source flow rate. The flow was visualized using KMnO4 dye and planar Laser Induced Fluorescence (LIF). The velocity fields for some cases were obtained using Particle Image Velocitymetry (PIV). To obtain the efficiency (that is percentage of source fluid entering the sink pipe), titration method is used. A small amount of hydrochloric acid (HCL) is added in the jet fluid through the overhead tank and the fluid collected at the sink is titrated with the Sodium hydroxide (NaOH) as base and Phenolphthalein as the pH indicator. The main characteristics of the jet, without a sink, were measured using PIV. The velocity profiles, jet widths and volume flow rates at various axial locations were obtained and compared with results reported in the literature for similar Reynolds number jets. For 100%, 70%, 50% and 25% efficiencies or removals and for zero lateral separations, the sink flow rate is about 1.5 times the flow rate predicted on the basis of jet properties at that point in the absence of a sink. The sink flow rate to obtain a certain efficiency increase dramatically with lateral separation; for example, when the lateral separation is about one half jet width, the required sink flow rate to obtain a certain efficiency increases by about five times. The sink diameter and the angle between source and the sink axes don’t influence efficiencies as much as the lateral separation. Data from our all experiments have been consolidated in the form of correlations that can be used for design of appropriate sinks for removal of heat and pollutants.

<p>Träbyggnandet i Sverige gick in i en ny era när myndigheterna beslutade att upphäva förbudet mot att bygga byggnader som är högre än två våningar. Denna förändring i lagstiftningen har bidragit till att utveckla träbyggandet under det senaste decenniet. Cross Laminerat Timber (CLT) har blivit erkänt som en ny teknik som använt på ett korrekt sätt ger starka och pålitliga konstruktioner. Materialet visar sig mer och mer intressant huvudsakligen beroende på den styvhet och styrka det visar i olika tester.</p><p>Ett av de projekt som använt CLT som bärande element är Limnologen i staden Växjö 500 kilometer söder om Stockholm. I detta projekt har både väggar och bjälklag med bärande delar av CLT använts. En av utmaningarna i samband med högre träbyggande är att beräkna och ta hänsyn till de vertikala förskjutningarna i stommen. Orsakerna till förskjutningen är momentana samt tidsberoende. I denna uppsats utvärderas dessa vertikala förskjutningar med två olika metoder. Den första av dessa är experimentell. Förskjutningarna mättes av en grupp forskare från Växjö universitet och utvärderas i denna rapport. Den andra är en Finit Element Modell där förskjutningarna simuleras beroende på parametrar som anses viktiga. Resultatet av simuleringen jämförs med de experimentellt erhållna värdena. Simulering är ett viktigt sätt att förutsäga förskjutningar i CLT byggnader i framtiden. Alla modeller har gjorts med hjälp av finita element programmet Abaqus.</p><p>FEM- modellen av Limnologen består av ett väggelement per våning i sex våningar. Detta element är det element där också förskjutningarna mätts på plats. På så sätt kan modell och verklighet jämföras. Förutom väggelement modelleras också bjälklagselement och kopplingen mellan vägg och bjälklag.</p><p>De experimentella resultaten har analyserats i programvaran Matlab. Resultatet blev ett antal grafer som redovisar förloppet. Det viktigaste resultatet är det som visar både den totala relativa förskjutningen samtidigt som den visar fuktkvoten i CLT- skivan. Fuktkvoten beräknades från temperatur och relativ luftfuktighet som båda mättes på plats.</p><p>Slutsatsen är att man med en simulering kan åstadkomma en acceptabel tillförlitlighet med avseende på vertikala förskjutningar. Krympningen har spelat en viktig roll för förskjutningarna. Den maximala förskjutningen som erhållits från mätningar var 21 mm medan det maximala förskjutningen fått från simuleringen baserad på tre olika antaganden var 35 mm, 33 mm och 17 mm. Skillnaden i resultaten kan delvis förklaras av de antaganden som använts för beräkning av fuktkvot och antagandet om fiberriktningen i timret. I simuleringen antogs fuktkvoten vara konstant över alla tre lager i CLT- skivan i de två första fallen. Orienteringen av fibrerna antogs radiell och tangentiell. Det tredje antagandet bygger på att fukten enbart påverkar det yttersta lagret i skivan. Detta antagande är rimligt på grund av tidsåtgången att uppnå fuktjämvikt och på grund av det limlager som skiljer lagren åt och hindrar fukt att vandra från ett lager till ett annat.</p> / <p>The history of timber buildings in Sweden entered a new era when the authorities decided to lift the ban on constructing more than two-storey timber buildings in Sweden. This change in legislations has contributed to the emergence of timber construction during the last decade. The Cross Laminated Timber (CLT) has become recognized as a new technology that used correctly in construction gives strong and reliable structures. The building material is gaining more credit day by day mainly due to the stiffness and strength it proved throughout the tests in projects where it was used.</p><p>One of the projects that used CLT as load bearing elements was Limnologen in the city of Växjö 500 kilometres south of Stockholm. In this project, a system of CLT floors as well as CLT walls has been used. One of the challenges related to medium-rise timber buildings in general is to calculate and take account of the vertical displacement of the whole building. The sources for the displacements are instantaneous elastic as well as time dependent. In this thesis we are introducing two evaluation methods for the vertical displacements in Limnologen. The first is the experimentally measured vertical displacement that was performed by a group of researchers from Växjö University, and the second is a Finite Element Model simulating the vertical displacement according to the factors and parameters thought to be important to be included in the modelling. The output of the simulation was to be compared with the experimentally obtained values. Simulation is an important way to predict the vertical displacement in future CLT buildings. All modelling were done using the finite element software Abaqus.</p><p>The Abaqus model of the Limnologen building consists of six wall elements from six storeys. The modelled wall elements are the wall elements that the vertical displacement devices were installed on. The reason for this is to get a better picture of how the results from the model would yield in comparison to the site measurements. The floor itself and the sylodyn used in the interface between wall and floor were also modelled.</p><p>The data collected from the site were processed in the software Matlab. Several graphs were attained out of the data processing. The most important graph is the one that include both the total relative displacement and the equivalent moisture content in the CLT. The equivalent moisture content was calculated from the measured temperature and relative humidity.</p><p>In this thesis it is concluded that a simulation can accomplish an acceptable reliability with respect to the vertical displacements. The shrinkage factor has played a vital role in simulation of the displacements. The maximum displacement obtained from the measurements was 21 mm while the maximum displacement gained from the simulation based on three different assumptions was 35 mm, 33 mm, and 17 mm respectively with the similar displacement pattern. The difference in the results can partly be explained by the assumptions used for the equivalent moisture content and local coordinate system of the CLT layers. In the simulation the moisture content was assumed to be equal over each layer of the CLT-panel. The first two assumptions were formulated due to the amphibolous grain of the middle layer of the CLT-panel which was considered having effect on the vertical displacement. The third assumption was formulated due to the glue layer between the wood layers of the CLT-panel which was considered having effect on preventing moisture diffuse from one layer to another layer. In reality it is questionable if the moisture content is varied in the different layers of the CLT-panel. The diffusion of the moisture content hasn't been taken into account.</p>

Direct methanol fuel cells (DMFC) are being investigated as a portable energy conversion device for military and commercial applications. DMFCs offer the potential to efficiently extract electricity from a dense liquid fuel. However, improvements in materials properties and lowering the cost of the electrocatalysts used in a DMFC are necessary for commercialization of the technology. The cathode electrocatalyst is a critical issue in DMFC because the state-of-the-art catalyst, platinum, is very expensive and rare, and its performance is diminished by methanol that crosses over from the anode to the cathode through the Nafion membrane. This thesis investigates the addition of platinum to a palladium-cobalt nanoalloy electrocatalyst supported on carbon black in order to improve catalyst activity for the oxygen reduction reaction (ORR) and catalyst stability against dissolution in acidic environment without significantly reducing the methanol-tolerance of the catalyst. Platinum was added to the palladium-cobalt nanoalloy catalyst using two synthesis methods. In the first method, platinum was directly alloyed with palladium and cobalt using a polyol reduction method, followed by heat treatment in a reducing atmosphere to form catalysts with 11 and 22 atom % platinum. In the second method, platinum was added to a palladium-cobalt alloy by galvanic displacement reaction to form catalysts with 10 and 22 atom % platinum. The palladium cobalt alloy was synthesized using a polyol method, followed by heat treatment in a reducing atmosphere to alloy the nanoparticles before the Pt displacement. It was found that both methods significantly improve catalyst activity and stability, with the displaced catalysts showing a higher activity than the corresponding alloy catalyst. However the alloy catalysts showed similar resistance to dissolution as the displaced catalysts, and the alloyed catalysts were more tolerant to methanol. The displaced catalyst with 22 atom % platinum (8 wt. % Pt overall) performed similar to a 20 wt. % commercial platinum catalyst in both RDE and single cell DMFC tests. The 10 and 22 atom % Pt displaced catalysts and 22 atom % Pt alloyed all showed higher Pt mass specific activities than a commercial Pt catalyst. / text

Enantioselective indicator displacement assays (eIDAs), was transitioned to a high-throughput screening protocols, for the rapid determination of concentration and enantioselectivity (ee) of chiral diols and α-hydroxycarboxylic acid. To improve the design of our previously established receptor based on o-(N,N-dialkylaminomethyl)arylboronate scaffolds for eIDAs. The rigidity of the receptor, which pertinent from the formation of an intramolecular N-B dative bond was investigated. o-(Pyrrolidinylmethyl)phenylboronic acid its complexes with bifunctional substrates such as catechol, [alpha]-hydroxyisobutyric acid, and hydrobenzoin was studied in detail by x-ray crystallography and ¹¹B NMR. Our structural study predicts that the formation of an N-B dative bond, and/or solvolysis to afford a tetrahedral boronate anion, depends on the solvent and the complexing substrate present. To simplify the operation of eIDAs, we introduced an analytical method, which utilize a dual-chamber quartz cuvette, which reduces the number of spectroscopic measurements from two to one and introduced artificial neural networks (ANNs) which simplifies data analysis. In a second example a high-throughtput screening protocol for hydrobenzoin was developed. The method involves the sequential utilization of what we define herein as screening, training, and analysis plates. Several enantioselective boronic-acid based receptors were screened using 96-well plates, both for their ability to discriminate the enantiomers of hydrobenzoin and to find their optimal pairing with indicators resulting in the largest optical responses. The best receptor/indicator combination was then used to train an ANN to determine concentration and ee. To prove the practicality of the developed protocol, analysis plates were created containing true unknown samples of hydrobenzoin generated by established Sharpless asymmetric dihydroxylation reactions, and the best ligand was correctly identified. The system was extended to pattern recognition for the rapid determination of identity, concentration, and ee of chiral vicinal diols. A diverse enantioselective sensor array was generated with three chiral boronic acid receptors and pH indicators. The optical response produced by the sensor array, was analyzed by two pattern recognition algorithms: principal component analysis (PCA) and ANNs. The PCA plot demonstrated good chemoselective and enantioselective separation of the analytes, and ANNs was used to accurately determine the concentration and ee of five unknown samples. / text

Traditional slope stability analysis and design methods, such as limit equilibrium method and continuum numerical methods have limitations in investigating three dimensional large scale rock slope stability problems in open pit mines associated with stress concentrations and deformations arising due to intersection of many complex major discontinuity structures and irregular topographies. Analytical methods are limited to investigating kinematics and limit equilibrium conditions based on rigid body analyses. Continuum numerical methods fail to simulate the detachment of rock blocks and large displacements and rotations. Therefore, there is an urgent need to try some new methods to have a deeper understanding of the open pit mine rock slope stability problems. The intact rock properties and discontinuity properties for both DRC and DP rock formations that exist in the selected open pit mine were determined from tests conducted on rock samples collected from the mine site. Special survey equipment (Professor Kulatilake owns) which has a total station, laser scanner and a camera was used to perform remote fracture mapping in the research area selected at the mine site. From remote fracture mapping data, the fracture orientation, spacing and density were calculated in a much refined way in this dissertation compared to what exist in the literature. Discontinuity orientation distributions obtained through remote fracture mapping agreed very well with the results of manual fracture mapping conducted by the mining company. This is an important achievement in this dissertation compared to what exist in the literature. GSI rock quality system and Hoek-Brown failure criteria were used to estimate the rock mass properties combining the fracture mapping results with laboratory test results of intact rock samples. Fault properties and the DRC-DP contact properties were estimated based on the laboratory discontinuity test results. A geological model was built in a 3DEC model including all the major faults, DRC-DP contact, and two stages of rock excavation. The built major discontinuity system of 44 faults in 3DEC with their real orientations, locations and three dimensional extensions were validated successfully using the fault geometry data provided by the mining company using seven cross sections. This was a major accomplishment in this dissertation because it was done for the first time in the world. Numerical modeling was conducted to study the effect of boundary conditions, fault system and lateral stress ratio on the stability of the considered rock slope. For the considered section of the rock slope, the displacements obtained through stress boundary conditions were seemed more realistic than that obtained through zero velocity boundary conditions (on all four lateral faces). The fault system was found to play an important role with respect to rock slope stability. Stable deformation distributions were obtained for k₀ in the range of 0.4 to 0.7. Because the studied rock mass is quite stable, it seems that an appropriate range for k₀ for this rock mass is between 0.4 and 0.7. Seven monitoring points were selected from the deformation monitoring conducted at the open pit mine site by the mining company using a robotic total station to compare with numerical predictions. The displacements occurred between July 2011 and July 2012 due to the nearby rock mass excavation that took place during the same period were compared between the field monitoring results and the predicted numerical modeling results; a good agreement was obtained. This is a huge success in this dissertation because such a comparison was done for the first time in the world. In overall, the successful simulation of the rock excavation during a certain time period indicated the possibility of using the procedure developed in this dissertation to investigate rock slope stability with respect to expected future rock excavations in mine planning.

Numerical simulations indicate that hydrocarbon migration and entrapment in stacked fault-bounded reservoirs are mainly affected by the following factors: charge time, faults, pressure and geological structures. The charge time for commercial hydrocarbon accumulation is much longer in oil-water systems than in oil-gas-water systems. Faults are classified into charging faults and 'back doors' faults other than charging faults in stacked fault-bounded reservoirs. The lower the displacement pressure of a fault, the higher its updip oil transportation ability. The downdip oil transportation ability of a fault is usually low and cannot cause commercial downdip oil accumulation. Back doors affect both hydrocarbon percent charge and hydrocarbon migration pathways. Updip back doors improve updip oil charge. The lower the displacement pressure of an updip back door, the more efficient the updip oil charge before 3,000 years. Back doors whose displacement pressure is equal to or higher than 28.76 psi are effective in sealing faults in oil-water systems. On the contrary, only sealing faults result in commercial gas accumulations in stacked fault-compartmentalized reservoirs. Otherwise gas is found over oil. Downdip back doors generally have few effects on downdip hydrocarbon charge. Geopressure enhances the updip oil transportation of a fault and improves the positive effects of updip back doors during updip oil charge. Geopressure and updip back doors result in more efficient updip oil charge. A physical barrier is not necessarily a barrier to oil migration with the aid of geopressure and updip back doors. The chance for hydrocarbon charge into reservoirs along growth faults is not equal. Any one of the above controlling factors can change the patterns of hydrocarbon charge and distribution in such complex geological structures. Generally, lower reservoirs and updip reservoirs are favored. Reservoirs along low-permeability charging faults may be bypassed. Gas can only charge the updip reservoirs. Both updip and downdip back doors can facilitate oil penetrating a barrier fault to charge reservoirs offset by the barrier fault. Interreservoir migration among stacked fault-compartmentalized reservoirs is an important mechanism for hydrocarbon accumulation and trap identification. The interreservoir migration is a very slow process, even though the displacement pressures of bounding faults may be very low.

Background: War disproportionately affects women and children, and gender based violence (GBV) has become an increasingly common means of fighting wars and targeting civilians. Such is the case in the Democratic Republic of Congo (DRC), particularly in the eastern provinces, where among the multitude of human rights violations, sexual violence and abuses against women and girls are committed on a large scale. Documented efforts addressing GBV in refugee communities have mainly focused on medical, programmatic, and legal responses; few studies explore the prevalence of GBV among conflict-affected populations. Objective: To determine the prevalence and correlates of outsider violence during and after conflict, and lifetime and past year intimate partner violence (IPV). To determine differences in the proportions of violence victimizations, including the differences in the proportions of outsider violence during and after conflict, and the differences in the proportions of lifetime and past year IPV. To describe patterns of reporting and healthcare seeking related to violence victimization. Methods: Cross sectional data were obtained from a sample of 810 women of reproductive age (WRA) living in two Rwandese refugee camps. GBV was defined as physical violence, sexual violence, or controlling behavior that is committed by intimate partners (IPV) or persons outside the family (outsider violence). Univariate analysis was used to describe the study population as a whole. The chi-square test for independence was used to measure significant differences between women who had identified experiencing GBV and those who did not. A z-test was conducted to explore differences in the proportions of outsider violence during and after conflict, and lifetime and past year IPV. Bivariate and multivariate logistic regression analyses were conducted to assess the unadjusted and adjusted associations between GBV and select variables of interest during and after conflict. Statistical analyses were conducted using SPSS version 14.0 Results: 434 WRA experienced GBV; of which 399 reported experiencing outsider violence before and after conflict, and 130 reported experiencing IPV. The logistical model indicated that there was a consistently significant association between a period of one to five years spent in a refugee camp and outsider violence during conflict (Adj.OR= 0.16; 95%CI:0.10-0.27; P <0.0001), lifetime IPV (Adj.OR=0.17;95%CI:0.10-0.32, p<0.0001), and IPV in the last year (Adj.OR= 0.15;95%CI:0.08-0.28, p<0.0001). Discussion: The results of this study illustrate the importance of assessing the impact of conflict on GBV among refugee and displaced populations. The high prevalence of GBV among this study population, with a prevalence of 53.3% for all forms of violence, is evidence of the great burden GBV poses on this population. Ongoing violence generated by conflict is a major public health concern that urgently requires effective interventions. For example, legal, health, and psycho-social services should be well integrated to adequately screen and address the needs of violence survivors.

Polymer pipes, typically high density polyethylene (HDPE), can be pulled-into-place, avoiding traditional cut-and-cover construction, using pipe bursting and horizontal directional drilling (HDD) pipe installation techniques. Of particular interest, are the ground displacements, induced by cavity expansion, associated with these techniques and the strains that develop in existing pipes in response to these displacements. Further, the axial stress-strain response of the new HDPE pipe during and after the cyclic pulling force history required to pull the pipe into place is of interest. Surface displacements and strains in an adjacent polyvinyl chloride (PVC) pipe induced by static pipe bursting were measured during the replacement of a new unreinforced concrete pipe. For the pipe bursting geometry tested, the maximum vertical surface displacement measured at the ground surface was 6 mm, while the distribution of vertical surface displacements extended no more than 2 m on either side of the centreline. The maximum longitudinal strain measured in the PVC pipe was less than 0.1% and its vertical diameter decreased by only 0.5%, suggesting that pipe bursting did not jeopardize the long-term performance of the water pipe tested. In addition, results from identical stress relaxation and creep tests performed on whole pipe samples and coupons trimmed from a pipe wall were compared, and these demonstrated that the coupons exhibited higher modulus than the pipe samples. Therefore, isolated pipe samples, as opposed to coupons, were tested to quantify the stress-strain response of HDPE pipe during the simulated installation, strain recovery, and axial restraint stages of HDD. Axial strains were found to progressively accumulate when an HDPE pipe sample was subjected to the cyclic stress history used to simulate an HDD installation. It was shown that existing linear and nonlinear viscoelastic models can serve as predictive design tools for estimating the cyclic strain history of HDPE pipe during installation. For the specific conditions examined, the tensile axial stresses redeveloped in the pipe samples, once restrained, were not large enough to lead to long-term stress conditions conducive to slow crack growth even when the short-term performance limits were exceeded by a factor of 1.5. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-04-01 18:19:24.434

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