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Downtown Revitalization Strategy Report for Glenrock, WYPhillips, Mary 01 December 2011 (has links)
ABSTRACT
Downtown Revitalization Strategy Report for Glenrock, WY
Mary E. Phillips
The following project submitted for the Master of City and Regional Planning Professional Project is the Downtown Revitalization Strategy Report for Glenrock, WY completed November 25, 2009.
At the onset of the project, the Town of Glenrock, WY was recognized as an Aspiring Main Street Community, and sought guidance to become a Certified Main Street Community. This Strategy Report was prepared to provide an implementation plan for revitalization of the downtown following the Main Street Approach, as well as for achievement of a Certified Main Street Community status by the year 2014.
The project included an interactive process, directly involving key representatives and stakeholders in the community. This included a public workshop and on-site strategy sessions with Town staff and the Glenrock Downtown Development Committee. The Strategy Report includes a basic assessment of existing conditions in downtown Glenrock based on information gathered at these meetings. From this initial assessment, issues, goals and objectives for downtown were identified. An overall strategy was then developed, in accordance with the Main Street Approach, which outlines the plan of action for the downtown revitalization and Main Street certification.
The implementation section of the plan then takes the identified actions and prioritizes them based on a 5-year implementation schedule. The development and prioritization of these actions was based on the following factors: Requirements for the Wyoming Main Street Community certification status Community goals for development in the downtown Feasibility of implementation of plan components Access to resources (of all types) for implementation Players in the implementation of the plan
The result of this methodology was a plan that addressed the community’s needs, with an implementation program specifically tailored for the community’s available resources.
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Reliability of Wafer-Level CSP Under Cyclic Bending TestTsai, Han-Hui 09 July 2004 (has links)
According to the fast development of portable electronic devices, their characteristics are inclined to miniature profile and lightweight. Nowadays, the wafer-level package (WLP) has been widely applied in portable electronic devices for its miniature profile and lightweight. It will become the mainstream trend later soon. The normal use of portable electronic devices brings low-frequency random vibrations to the electronic packages inside. Because of the increasing demand of these devices, the reliability of electronic packages subjected to repeated mechanical loads has become an important issue in the contemporary electronic packaging industry.
In this paper both numerical and experimental studies were carried out to investigate the reliability life of Ultra-CSP under cyclic bending conditions. We perform four-point cyclic bending with various combinations of amplitudes and frequencies. Then, we do failure analysis in Ultra-CSP by observing the failure modes. A finite element model for the package is built up for dynamic as well as quasi-static analyses. Accumulated plastic work per bending cycle within the critical solder ball were calculated and together with the experimental results the parameters for the Coffin-Manson fatigue equation were fitted.
Through finite element analysis we find that the solder ball which located in the corner has higher accumulated plastic work. Therefore, the crack in the solder ball grew more easily. Thus it lets package resistance rise to determine failure. It was observed from the bending experiments that the influence of frequencies on the fatigue life of the solder interconnects is inapparent. However, influence of amplitude is significant. From the results of both experiments and FEA, it was found that for this particular ultra-CSP specimen under cyclic bending conditions, the characteristic life was expressed as
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Validation of Point and Pressure Loading Models for Simply Supported Composite Sandwich BeamsWright, Bryan K. 27 November 2012 (has links)
Stiffness and strength models are derived for simply supported composite sandwich panels comprised of fibre-reinforced face sheets and polymer cores subject to symmetric four point bending and uniformly distributed loading. Optimal trajectories for minimum mass design are calculated using the models and situated on failure mechanism maps. A stiffness constraint is also derived to omit beam designs of excessive compliance. Analytical models were validated through an extensive series of experiments, considering beams comprised of GFRP face sheets with ROHACELL 51-IG and extruded polystyrene (EPS) polymer cores. An alternate loading fixture was used to simulate uniform pressure loads. In general, experiments were able to validate most analytical expressions for a range of experimental conditions. Though the predictions worked well with most beam cases, analytical models were noted to become unreliable for short or slender beams.
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Validation of Point and Pressure Loading Models for Simply Supported Composite Sandwich BeamsWright, Bryan K. 27 November 2012 (has links)
Stiffness and strength models are derived for simply supported composite sandwich panels comprised of fibre-reinforced face sheets and polymer cores subject to symmetric four point bending and uniformly distributed loading. Optimal trajectories for minimum mass design are calculated using the models and situated on failure mechanism maps. A stiffness constraint is also derived to omit beam designs of excessive compliance. Analytical models were validated through an extensive series of experiments, considering beams comprised of GFRP face sheets with ROHACELL 51-IG and extruded polystyrene (EPS) polymer cores. An alternate loading fixture was used to simulate uniform pressure loads. In general, experiments were able to validate most analytical expressions for a range of experimental conditions. Though the predictions worked well with most beam cases, analytical models were noted to become unreliable for short or slender beams.
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Supercritical Fluid Deposition of Thin Metal Films: Kinetics, Mechanics and ApplicationsKaranikas, Christos F. 01 February 2009 (has links)
In order to meet the demands of the continuous scaling of electronic devices, new technologies have been developed over the years. As we approach the newest levels of miniaturization, current technologies, such as physical vapor deposition and chemical vapor deposition, are reaching a limitation in their ability to successfully fabricate nano sized electronic devices. Supercritical fluid deposition (SFD) is a demonstrated technology that provides excellent step coverage for the deposition of metals and metal oxides within narrow, high aspect ratio features. This technique shows the potential to satisfy the demands of integrated circuit miniaturization while maintaining a cost effective process needed to keep the technology competitive. In order to complement SFD technology heuristics for scale-up, an understanding of the deposition mechanism and kinetics and resolution of integration issues such as interfacial film adhesion must be resolved. It is critical to have a fundamental understanding of the chemistry behind the reaction process in supercritical fluid deposition. For this purpose, a detailed kinetic study of the deposition of ruthenium from bis(2,2,6,6-tetramethyl-3,5-heptanedionato) (1,5-cyclooctadiene) ruthenium(II) is carried out so that growth rate orders and a mechanism can be established. These predictive kinetic results provide the means to control the reaction which allows for overall optimization of the process. Reliability is of the utmost importance for fabricated devices since they must withstand harsh steps in the fabrication process as well as perform and last under standard and extreme usage conditions. One issue of reliability is assessed by addressing the adhesion of the metallization layers deposited by SFD. A quantitative determination of the interfacial adhesion energy of as deposited and pretreated copper metallization layers from SFD onto barrier layers is used to determine the potential for integration of these films for industry standards. Extension of the basics of SFD by performing co-deposition of multiple compounds, layer-by-layer deposition for device fabrication and integration with other unique technologies for novel applications demonstrates the ability of this technique to satisfy a wide range of commercial applications and be used as the basis for new technologies. Co-depositions of Ce/Pt, Co/Pt, Ba/Ti and Nd/Ni for the fabrication of functional direct methanol fuel cell electrodes, magnetic alloys for media storage applications, high k dielectric films for alternative energy storage devices and alternative materials for solid oxide fuel cell cathodes, respectively, are performed. Layer-by-layer deposition with masking is used to fabricate nanometer scale capacitors. Finally, plasma spray technology is combined with the rapid expansion of supercritical solvents technique to form a novel, patent pending, process that is used to fabricate next generation photovoltaic cells.
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Method evaluation : Electrical surface resistance measurements on coated conductive textilesWisung, Grete January 2018 (has links)
This thesis has evaluated how electrical surface resistance can be measured on conductive coated textiles using two different probes. The electrical surface resistance is a measurement for how difficult it is for current to flow through a material. For textiles, the surface resistance can be measured using four metallic plates, that measure the difference between current supply and voltage drop, this method is called a linear four-point probe. There is no standard method for measuring the electrical surface resistance on conductive textiles. Therefore, it is not possible to compare textiles made by different producers. It is also not possible to decide what the true resistance is and as conductive textiles are becoming more popular to use, this has started to become a problem in the industry. Two probes with electrodes of different dimensions were used to evaluate how different electrodes would affect the measured resistance. Measurements were conducted on conductive coated textiles with varying parameters, like coating thickness, sample size and textile construction, to show how the electrical resistance properties differ depending on what probe was used. It was found that in contrast to other research on conductive textiles and collinear four-point probes, the probes used in this study could detect electrical anisotropic properties. The resistance was different depending on what angle it was measured in. This was found for both a thicker coating and a thinner one. It was also found that the probes could detect a correlation between the angular resistance and the textile construction used. By measuring the resistance on small samples with the same dimension as the probes electrodes, the resistance was increased compared to when measurements were conducted on samples with dimensions significantly larger than the probes. Furthermore, the results showed that increasing the distance between the inner electrodes of the probe decreased the measured resistance for both large and small samples. Additionally, it was found that by increasing the width of the outer electrodes the resistance was decreased, an increase in outer electrode width also made it easier to detect electrical anisotropic properties.
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Compósitos com biochar e carvão vegetal para camadas de pavimentos asfálticos / Composites with biochar and vegetable charcoal for asphalt pavement layersTorres, Alemar Pereira, 92981056447 18 June 2018 (has links)
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Previous issue date: 2018-06-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Biochar is a charcoal derived from the carbonization of biomass under a low oxygen atmosphere. Its origin is due to the study developed in the so-called "Indian black earth", which considerably improves the agricultural properties of a soil. In the work under study the influence of biochar as a participant of composites with soil and asphalt mixtures is analyzed by means of the four point bending test. We also compare these results regarding the responses of the formulations with the presence of native charcoal from the Amazon region. For this, prismatic formations of natural clay soil (SN), soil-charcoal (SCV), soil-biochar (SBC), asphalt concrete (CA), asphalt-charcoal concrete (CACV) and concrete asphalt-biochar (CABC). The results showed that the biomass, which participates in composites with the clay soil, improved the stiffness properties, with the purpose of its use in base and sub-base of pavements, culminating in higher values for complex module regarding the mixtures with charcoal . Allus asphaltic composites with biochar and charcoal were verified for both values of stiffness inferior to the standard asphalt concrete, considering average temperature of 25oC. However, for the 40oC temperature, representative of the surface of the pavements of the city of Manaus, these formulations proved to be more advantageous in comparison to the concrete reference, conceiving an alternative for the achievement of road systems with better performance in the Amazon region. / O biochar é um carvão vegetal oriundo da carbonização de biomassa sob baixa atmosfera de oxigênio. Sua origem deve-se ao estudo desenvolvido na chamada “terra preta de índio”, a qual melhora consideravelmente as propriedades agrícolas de um solo. No trabalho em pauta analisa-se a influência do biochar como partícipe de compósitos com solo e misturas asfálticas, por meio do ensaio de flexão a quatro pontos. Também se comparam tais resultados relativos as respostas das formulações com a presença do carvão vegetal nativo da região amazônica. Para tal moldaram-se os corpos de prova de formato prismático do solo argiloso natural (SN), solo-carvão vegetal (SCV), solo-biochar (SBC), concreto asfáltico (CA), concreto asfáltico-carvão vegetal (CACV) e concreto asfáltico-biochar (CABC). Os resultados registraram que o biocarvão, participante em compósitos com o solo argiloso, melhorou as propriedades de rigidez, com a finalidade de seu emprego em base e sub-base de pavimentos, culminando em maiores valores para módulo complexo respeitante as misturas com o carvão vegetal. Alusivo aos compósitos asfálticos com biochar e carvão vegetal, verificou-se para ambos valores de rigidez inferior ao concreto asfáltico padrão, considerando temperatura média de 25oC. No entanto, para a temperatura de 40oC, representativa da superfície dos pavimentos da cidade de Manaus, tais formulações se mostraram mais vantajosos frente ao concreto referência, concebendo uma alternativa para a consecução de sistemas viários com melhor desempenho na região Amazônica.
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Developing a Four-Point Bending Apparatus to Measure Bending Stiffness of Corrugated BoardSingh, Manjeet January 2021 (has links)
No description available.
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The Effects of a Damage Arrestment Device on the Mechanical Behavior of Sandwich Composite Beams Under Four-Point BendingDavis, Richard Anthony 01 June 2011 (has links) (PDF)
The demand for an insert on composite sandwich structures to aid in the arrestment of face-core delamination is of great need. This research studies the use of a damage arrestment device (DAD) that connects the carbon fiber face sheets to the foam core to find whether an increase in the structural integrity of the sandwich beam results. Experimental analysis was employed to test the samples and was verified by a theoretical and finite element approach.
The mechanical properties of LTM45/CF1803 pre-impregnated carbon fiber and Last-A-foam FR 6710 polyvinylchloride foam were experimentally analyzed using ASTM D3039 and ASTM D1621 standards respectively to verify the manufacturer’s data for the given material. With all the mechanical data, the effects of adding DAD keys to a delaminated composite sandwich beam were studied under a four-point bending test using ASTM standard D6272 and compared with non-delaminated beams to see if an increase in ultimate strength could be achieved. The initial delamination in the beams under consideration was one inch in length and located in between the loaded span of the beam. Two control beams were utilized for comparison: one with no defects, and another with a one inch delamination introduced at the face-core interface. The DAD keys were added in two different configurations to potentially stop the delamination propagation and increase the ultimate strength. In the first configuration DAD keys were added 0.25 inches on either side of the initial delamination in the transverse direction and provided a significant increase in strength over the delaminated control beam. The second configuration had a DAD key running along the longitudinal axis of the sandwich beam and resulted in a significant increase in ultimate strength over the delaminated control beam. After testing ten successful samples for each of the six different configurations, it was concluded that the addition of DAD keys in both configurations significantly increased the structural integrity of both the delaminated and non-delaminated control beams.
With all the experimental data acquired, finite element models were created in COSMOS. The purpose of the finite element analysis was to validate the experimental results by comparing the deflections of the beam subjected to four-point bending during the experiment to the deflections found numerically. The deflections for the various DAD key configurations found in the experimental work were in agreement with the finite element results.
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Effects of Low Velocity Impact on the Flexural Strength of Composite Sandwich StructuresCarter, Jeffrey Scott 01 October 2014 (has links) (PDF)
The use of composite sandwich structures is rapidly increasing in the aerospace industry because of their increased strength-to-weight and stiffness-to-weight characteristics. The effects of low velocity impacts on these structures, however, are the main weakness that hinders further use of them in the industry because the damages from these loadings can often be catastrophic. Impact behavior of composite materials in general is a crucial consideration for a designer but can be difficult to describe theoretically. Because of this, experimental analysis is typically used to attempt to describe the behavior of composite sandwiches under impact loads. Experimental testing can still be unpredictable, however, because low velocity impacts can cause undetectable damage within the composites that weaken their structural integrity. This is an important issue with composite sandwich structures because interlaminar damage within the composite facesheets is typical with composites but the addition of a core material results in added failure modes. Because the core is typically a weaker material than the surrounding facesheet material, the core is easily damaged by the impact loads. The adhesion between the composite facesheets and the core material can also be a major region of concern for sandwich structures. Delamination of the facesheet from the core is a major issue when these structures are subjected to impact loads.
This study investigated, through experimental and numerical analysis, how varying the core and facesheet material combination affected the flexural strength of a composite sandwich subjected to low velocity impact. Carbon, hemp, aramid, and glass fiber materials as facesheets combined with honeycomb and foam as core materials were considered. Three layers of the same composite material were laid on the top and bottom of the core material to form each sandwich structure. This resulted in eight different sandwich designs. The carbon fiber/honeycomb sandwiches were then combined with the aramid fiber facesheets, keeping the same three layer facesheet design, to form two hybrid sandwich designs. This was done to attempt to improve the impact resistance and post-impact strength characteristics of the carbon fiber sandwiches. The two and one layer aramid fiber laminates on these hybrid sandwiches were always laid up on the outside of the structure. The sandwiches were cured using a composite press set to the recommended curing cycle for the composite facesheet material. The hybrid sandwiches were cured twice for the two different facesheet materials. The cured specimens were then cut into 3 inch by 10 inch sandwiches and 2/3 of them were subjected to an impact from a 7.56 lbf crosshead which was dropped from a height of 38.15 inches above the bottom of the specimen using a Dynatup 8250 drop weight machine.
The impacted specimen and the control specimen (1/3 of the specimens not subjected to an impact) were loaded in a four-point bend test per ASTM D7250 to determine the non-impacted and post-impact flexural strengths of these structures. Each sandwich was tested under two four-point bend loading conditions which resulted in two different extension values at the same 100 lbf loading value. The span between the two supports on the bottom of the sandwich was always 8 inches but the span between the two loading pins on the top of the sandwich changed between the two loading conditions. The 2/3 of the sandwiches that were tested after being impacted were subjected to bending loads in two different ways. Half of the specimens were subjected to four-point bending loads with the impact damage on the top facesheet (compressive surface) in between the loading pins; the other half were subjected to bending loads with the damage on the bottom facesheet (tensile surface).
Theoretical failure mode analysis was done for each sandwich to understand the comparisons between predicted and experimental failures. A numerical investigation was, also, completed using Abaqus to verify the results of the experimental tests. Non-impacted and impacted four-point bending models were constructed and mid-span deflection values were collected for comparison with the experimental testing results. Experimental and numerical results showed that carbon fiber sandwiches were the best sandwich design for overall composite sandwich bending strength; however, post-impact strengths could greatly improve. The hybrid sandwich designs improved post-impact behavior but more than three facesheet layers are necessary for significant improvement. Hemp facesheet sandwiches showed the best post-impact bending characteristics of any sandwich despite having the largest impact damage sizes. Glass and aramid fiber facesheet sandwiches resisted impact the best but this resulted in premature delamination failures that limited the potential of these structures. Honeycomb core materials outperformed foam in terms of ultimate bending loads but post-impact strengths were better for foam cores. Decent agreement between numerical and experimental results was found but poor material quality and high error in material properties testing results brought about larger disagreements for some sandwich designs.
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