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Parental Divorce, Psychological Distress and Academic Achievement of College StudentsHawkins, Julie Ellen 09 April 2008 (has links)
Parental divorce is a stressful process that has been associated with long-term developmental implications for the children involved. There have been mixed results from research regarding specific effects of parents' marital status on levels of psychological distress and academic achievement in late adolescence and early adulthood. Research using a clinical sample from a college counseling center was lacking altogether. The primary goal of this study was to establish if there are relationships between parents' marital status, students'degree of psychological distress and academic achievement within a clinical sample of college undergraduates. The secondary goal was to determine if student gender interacts with parents' marital status on measures of psychological distress and academic achievement. Participants included 324 undergraduate college students aged 17-24 years who received clinical services at a student counseling center of a private university in a large metropolitan area in the Southeastern United States. Primary analyses found no statistically significant differences for self-reported GPA and therapists' perception of psychological distress by parents' marital status (married, divorced or divorced/remarried). In addition, it was found that gender did not have a statistically significant interaction with parents' marital status on psychological distress or academic achievement. Student's residential status was found to significantly covary with psychological distress, suggesting that students who lived off campus were perceived as being significantly more distressed than students who lived on campus, independent of parents' marital status. Results of this study have implications for college counseling center personnel to obtain a thorough family history at intake and monitor changes in residential status throughout the course of treatment. Results of this study also have implications for university administrators and student affairs personnel to include researching, planning and implementing interventions and programming for commuter students, and possibly expanding on-campus housing.
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On the Flow Characteristics behind a Backward-facing Step and the Design of a New Axisymmetric Model for their StudyRajasekaran, Jagannath 19 December 2011 (has links)
An extensive review was made to study the wake characteristics of a backward-facing step. Experimental and numerical studies of the backward-facing step suggest that the wake of a separated shear layer to be dependent on parameters such as: expansion ratio, aspect ratio, free stream turbulence intensity, boundary layer state and thickness at separation. The individual and combined effects of these parameters on the reattachment length are investigated and discussed in detail in this thesis. A new scaling parameter, sum of step height and boundary layer thickness at separation is proposed, which yields significant collapse of the available data. Based on the literature review, an axisymmetric model is designed for further investigating the dynamics of the flow independent of aforementioned parameters. Additionally, porous suction strips are incorporated to study the step wake characteristics independent of Reynolds number. This model has been built and will be tested extensively at UTIAS.
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On the Flow Characteristics behind a Backward-facing Step and the Design of a New Axisymmetric Model for their StudyRajasekaran, Jagannath 19 December 2011 (has links)
An extensive review was made to study the wake characteristics of a backward-facing step. Experimental and numerical studies of the backward-facing step suggest that the wake of a separated shear layer to be dependent on parameters such as: expansion ratio, aspect ratio, free stream turbulence intensity, boundary layer state and thickness at separation. The individual and combined effects of these parameters on the reattachment length are investigated and discussed in detail in this thesis. A new scaling parameter, sum of step height and boundary layer thickness at separation is proposed, which yields significant collapse of the available data. Based on the literature review, an axisymmetric model is designed for further investigating the dynamics of the flow independent of aforementioned parameters. Additionally, porous suction strips are incorporated to study the step wake characteristics independent of Reynolds number. This model has been built and will be tested extensively at UTIAS.
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A Step Implementation For Product Structure Data ExchangeQian, Jingjing January 2012 (has links)
Scania is a Swedish automotive manufacturer for heavy vehicles and engines. It also offers transport solutions and long term commitment for customers. In today's Scania, a modular system provides a huge variety of specifications to meet varying dramatic needs for different customers. In order to be able to meet the diverse requirements of customers, modular approach with the support of reusable components is used to increase the efficiency of designing different products. To customize both product development and product design, computer aided design(CAD) is used to support the process of design and design documentation. "CATIA" is a multi-platform CAD software and "ENOVIA" is a product modeling product offers product database management for virtual model design into CATIA, both "CATIA" and "ENOVIA" are developed by the French company Dassault Systemes are chosen by Scania to support its product development. The modular system approach requires the system support for product structure, which is managed by a mainframe called SPECTRA. The thesis project is mainly about system designing a new module which takes the responsibility for exchanging information between SPECTRA and ENOVIA. In more detail, the new component is to perform a mapping of data in SPECTRA format into a format which ENOVIA can import. The mapping module has several interfaces with other applications in the system. JavaMigrator provides the environment to import data from the mainframe and transfer the data into the module and finally output the expected data format into ENOVIA. To achieve this purpose, several possible solutions were proposed and several methods were tried. Since an in-house developed CAA-module is highly preferred by Scania, the new mapping component will finally be designed into two separate modules, the first part converts the XML extracted from SPECTRA into an intermediate format and the second part is designed to convert the intermediate file into the expected target file. The intermediate file is required, since the format is independent of changes in both SPECTRA and ENOVIA. Furthermore, it is flexible and less complex to maintain than direct mapping from exported XML to ENOVIA. The report focuses on five parts, background, project specification, methodology, implementation, result and future work.
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The optimal pricing strategy of golf clubs' membershipHsu, Pei-chi 17 July 2004 (has links)
Due to the increasing of substitution and competition of products, the life cycle of products is shorter than previous time and the perishable has becoming visible for service industry and other related manufacturing industries.
Wrong strategy and management of pricing make many companies lose the right opportunity to invest and even trapped in the bad financial structure with the apparent character.
More and more private club managers use the concept of yield management to deal with their problems and maximize their benefits because of the property of perishable in recent years.
However most researchers study about ways to improve the performance and to understand the distribution of consumers¡¦ recognition instead of realizing the factors impacting the products¡¦ pricing.
I will develop an initial pricing model and find out how the relationship among the factors which influence the products¡¦ pricing interacts by this model
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Experimental response of a rotor supported on Rayleigh step gas bearingsZhu, Xuehua 15 November 2004 (has links)
Gas bearings enable successful applications in high speed oil-free microturbomachinery. This thesis presents analysis and experiments of the dynamic performance of a rotor supported on Rayleigh step gas bearings. Comprehensive experiments demonstrate that Rayleigh step hybrid gas bearings exhibit adequate stiffness and damping capability in a narrow range of shaft speeds, up to ~ 20 krpm.
Rotor coastdown responses were performed for two test bearing sets with nominal radial clearance of 25.4 ?m and 38.1 ?m, respectively. A near-frictionless carbon (NFC) coating was applied on the rotor to reduce friction against its bearings at liftoff and touchdown. However, the rotor still experienced dry friction at low shaft speeds (below ~ 4,000 rpm). Experiments show that the supply pressure raises the rotor critical speed and decreases the system damping ratio. The geometry of the Rayleigh steps distributed on the rotor surface generates a time varying pressure field and results in a sizable 4X super synchronous component of bearing transmitted load. The external supply gas pressure affects slightly the onset speed of instability of the rotor-bearing system. The unstable whirl frequencies are nearly fixed at the system natural frequency (~ 120 Hz).
Analysis with a finite element model predicts the stiffness and damping force coefficients for the bearing accounting for a purely hydrodynamic operation condition. Predictions show the synchronous stiffness and damping coefficients decrease with shaft speed. Predicted threshold speeds of instability are lower, ~ 50% or less than the measurement due to the analytical model limitations assuming a grooved stator. The predicted synchronous responses to imbalance correlate well with the measurements, however.
The Rayleigh step gas bearing shows similar characteristics to the flexure pivot tilting pad bearing (FPTPB) tested in 2003. However, the test Rayleigh step gas bearings exhibit a much reduced stable operating speed range, below 20 krpm. The maximum speed achieved is much lower to that determined with an identical rotor supported on FPTPBs, i.e. rotor dynamically stable up to 100 krpm. The FPTPB is more reliable in high speed oil-free applications due to its excellent stability characteristics.
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Numerical simualtion of mixed convection over a three-dimensional horizontal backward-facing stepBarbosa Saldana, Juan Gabriel 29 August 2005 (has links)
A FORTRAN code was developed to numerically simulate the mixed convective flow over a three-dimensional horizontal backward-facing step. The momentum and energy equations under the assumption of the Boussinesq approximation were
discretized by means of a finite volume technique. The SIMPLE algorithm scheme was applied to link the pressure and velocity fields inside the domain while an OpenMP
parallel implementation was proposed to improve the numerical performance and to accelerate the numerical solution. The heating process corresponds to a channel heated from below at constant temperature keeping insulated all the other channel walls. In addition, the back-step was considered as a thermally conducting block and its influence in the heating process was explored by holding different solid to fluid thermal conductivity ratios. The effects over the velocity and temperature distribution of buoyancy forces, acting perpendicular to the mainstream flow, are studied for three different Richardson numbers Ri=3, 2, and 1 and the results are compared against those of pure forced convection Ri=0. In these simulations the Reynolds number is fixed at 200 while the bottom wall temperature is adjusted to fulfill the conditions for the different Ri. Under this assumption, as Ri increases the buoyancy effects are the dominant effects in the mixed convective process.
The numerical results indicate that the velocity field and the temperature distribution for pure forced convection are highly distorted if compared with the mixed
convective flow. If the Ri parameter is increased, then the primary re-circulation zone is reduced. Similarly, as the buoyancy forces become predominant in the flow, the
convective rolls, in the form of spiral-flow structures, become curlier and then higher velocity components are found inside the domain. The temperature field distribution showed that as the Ri is increased a thicker layer of high temperature flow is located at the channel??s top wall as a result of the higher rates of low-density flow moving to the top wall. The flow is ascending by the channel sidewalls, while descending by the channel span-wise central plane. The parallel numerical strategy is presented and some results for the performance of the OpenMP implementation are included. In this sense, linear speedup was obtained when using 16 possessors in parallel.
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Enhancing the practical usability of dynamic traffic assignmentPool, Christopher Matthew 04 March 2013 (has links)
A general framework is presented for replacing static traffic assignment with dynamic traffic assignment within the standard four step transportation planning model. Issues including model consistency and the implementation of a proper feedback loop are explored. The new model is compared with the standard four step model in order to highlight the benefits of using dynamic traffic assignment rather than static. The model is then extended to include a term for the difference between experienced and free-flow travel times, which can be used as a proxy for travel time reliability and highlights the benefits of time-dependent DTA. Additionally, a study on improving the quality of convergence for dynamic traffic assignment is conducted in order to help facilitate the usefulness of this modeling approach in practice. A variety of equilibration techniques are tested, and analysis is performed to contrast these techniques with the method of successive averages. / text
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Boundary conditions for modeling deposition in a stochastic Lagrangian particle modelJonsson, Tobias January 2015 (has links)
The Swedish defence agency (FOI) has developed a particle model (called Pello) that simulates the dispersion of aerosols and gases. At the boundaries, such as the ground, the particles can either reflect back into the domain (the atmosphere) or be absorbed. Which of the events that occurs is decided by a certain probability, which in the present model depends on mere physical properties. In this thesis we have investigated a newly proposed boundary behaviour which also depends on the time step used in the numerical simulations. We verified the accuracy of the new model by using a dispersion model with an explicit solution. To gain a better understanding of how important parameters at the boundary influence each other, we performed a sensitivity analysis. Simulations showed an overall improving concentration profile as the time step became smaller and the new model working well. The convergence order of the simulations was found to be close to 0.5. In this thesis we have shown that there exist an upper limit for the time step, which depends on the specific model. The present used time step at FOI does not have this versatile property. But having this upper limit for the time step close to the boundary, and a uniform time step can be time demanding. This lead us to the conclusion that an adaptive time step should be implemented.
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Materials development for step and flash imprint lithographyJacobsson, Borje Michael 23 September 2011 (has links)
The quest for smaller and faster integrated circuits (ICs) continues, but traditional photolithography, the patterning process used to fabricate them, is rapidly approaching its physical limits. Step and Flash Imprint Lithography (S-FIL®) is a low-cost patterning technique which has shown great potential for next generation semiconductor manufacturing. To date, all methods of imprint lithography have utilized a sacrificial resist to produce device features. Our goal has been to develop functional materials such as insulators that can be directly patterned by S-FIL and then remain as a part of the end product. Directly patternable dielectric (DPD) materials must meet multiple mechanical and physical requirements for application in microelectronic devices. In some cases these requirements are conflicting, which leads to material design challenges. Many different materials and curing methods have been evaluated. Thiol-ene based approaches to patterning hyperbranched materials incorporating Polyhedral Oligomeric Silsesquioxanes (POSS) have shown the greatest promise. Thiol-ene polymerization takes place by a free radical mechanism, but it has the advantage over acrylates of not being inhibited by the presence of oxygen. This greatly eases some engineering design challenges for the S-FIL process. A number of thiol-ene formulations have been prepared and their mechanical and electrical properties evaluated.
SFIL-R has been introduced as an alternative technology to SFIL. SFIL-R offers improvements to SFIL in several ways, but requires a high silicon content, low viscosity, planarizing material. Photopolymerizable branched siloxanes were synthesized and evaluated to function as a planarizing topcoat for this technology.
Both SFIL and SFIL-R require a clean separation of the template from the resist material. Fouling of templates is a major concern in imprint lithography and fluorinated materials are used to treat templates to lower their surface energy for better separation. It has been observed that the template treatment degrades over time and needs to be replaced for further imprinting. A fluorinated silazane was designed to repair the degraded areas. This material was evaluated and functions as designed. / text
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