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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.
41

DEVELOPMENT OF THE TEAR-PEEL TEST FOR PAPER TOWELS

El-Darazi, Samir 16 February 2011 (has links)
No description available.
42

Chapas metálicas perfuradas para proteção solar. Avaliação do desempenho térmico e luminoso / Perforated metal sheet for shading. Assessment of solar-optical performance

Minioli, Alda Regina Bueno 16 April 2014 (has links)
Neste trabalho é realizada a avaliação do desempenho solar e luminoso de chapas metálicas com diferentes padrões de perfurações empregados para proteção solar na envoltória das edificações. Foram ensaiadas experimentalmente as transmitâncias solar e luminosa em diversos ângulos de incidência de chapas metálicas, chapas expandidas e telhas metálicas, com ou sem pintura, planas ou com conformação espacial. Avaliou-se a relação entre a transmitância e % de perfuração da amostra para incidência da radiação em variadas alturas e azimutes solares, comparou-se o comportamento solar e luminoso de cada amostra e entre amostras com características semelhantes. As normas ASTM E972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight e ASTM E1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight foram adotadas para medições de campo das amostras. Os resultados mostram que, para todas as amostras, as transmitâncias solar (TS) e luminosa (TL) na perpendicular se assemelham a % de perfuração da amostra; para ângulos diferentes da normal há uma redução conforme a altura solar diminui e que quanto maior for o furo em relação à espessura, menor será a redução. TS/TL decresce conforme a altura solar diminui, exceto para as telhas. Em relação à variação de azimute, para chapas perfuradas sem acabamento ou pintadas, os valores de TS e TL se mantêm praticamente iguais, enquanto que para chapas expandidas e telhas os valores variam. Para as amostras pintadas, TS e TL das amostras com cores claras são maiores do que das amostras com cores médias que por sua vez são maiores do que as amostras com cores escuras. A partir destes resultados e da elaboração da ficha de aplicação dos resultados para variados ângulos, no âmbito do projeto de arquitetura, contribui-se para o emprego apropriado deste tipo de material, além de complementar informações técnicas pouco disponíveis no mercado. Além disso, os dados medidos em campo podem servir de validação para modelagem computacional para uma variação maior de ângulos, e na avaliação de ambientes projetados ou construídos, os dados coletados, em especial os ângulos diferentes da incidência normal, podem ser usados em simulação energética ao longo do ano. / This research focuses on the evaluation of solar and optical performance of metal sheets with different patterns of perforations used as shading devices in the building\'s envelope. Solar and light transmittance were experimentally tested at normal and off-normal incident angles of samples of perforated metal sheet, expanded metal sheets and perforated tile, with or without painting, flat or volumetric shape. The relationship between % perforation of sample and transmittance for off normal angle incidence (height and azimuth) was evaluated. Solar and optical results were correlated for each sample. Samples with similar characteristics such as perforation, painting, hole dimension were compared. ASTM E 972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight and ASTM E 1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight were adopted for field measurements of the samples. The results show that for all samples, the solar transmittance (TS) and light (TL) perpendicular to the sample is similar to % perforation; for off normal angles there is a reduction as the solar altitude decreases and that the higher the hole relative to thickness, the smaller the reduction. TS / TL decreases as solar height decreases, except for the tiles. Regarding the change in azimuth for perforated sheets with or without painting, the values of TL and TS remains practically the same, whereas for expanded metal and tiles values vary. For the painted samples, TS and TL bright color of the samples are higher than the intermediate color samples which are in turn higher than the samples of dark colors. From the results achieved and with the development of the application table to diferente incident angles, within the architecture field, these results provide information for the appropriate use of such material, plus some additional technical information available in the market. Furthermore, the data measured in the field can serve as validation for computational modeling to a wider range of angles, and also it could be used in buildings\' energy simulations.
43

Chapas metálicas perfuradas para proteção solar. Avaliação do desempenho térmico e luminoso / Perforated metal sheet for shading. Assessment of solar-optical performance

Alda Regina Bueno Minioli 16 April 2014 (has links)
Neste trabalho é realizada a avaliação do desempenho solar e luminoso de chapas metálicas com diferentes padrões de perfurações empregados para proteção solar na envoltória das edificações. Foram ensaiadas experimentalmente as transmitâncias solar e luminosa em diversos ângulos de incidência de chapas metálicas, chapas expandidas e telhas metálicas, com ou sem pintura, planas ou com conformação espacial. Avaliou-se a relação entre a transmitância e % de perfuração da amostra para incidência da radiação em variadas alturas e azimutes solares, comparou-se o comportamento solar e luminoso de cada amostra e entre amostras com características semelhantes. As normas ASTM E972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight e ASTM E1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight foram adotadas para medições de campo das amostras. Os resultados mostram que, para todas as amostras, as transmitâncias solar (TS) e luminosa (TL) na perpendicular se assemelham a % de perfuração da amostra; para ângulos diferentes da normal há uma redução conforme a altura solar diminui e que quanto maior for o furo em relação à espessura, menor será a redução. TS/TL decresce conforme a altura solar diminui, exceto para as telhas. Em relação à variação de azimute, para chapas perfuradas sem acabamento ou pintadas, os valores de TS e TL se mantêm praticamente iguais, enquanto que para chapas expandidas e telhas os valores variam. Para as amostras pintadas, TS e TL das amostras com cores claras são maiores do que das amostras com cores médias que por sua vez são maiores do que as amostras com cores escuras. A partir destes resultados e da elaboração da ficha de aplicação dos resultados para variados ângulos, no âmbito do projeto de arquitetura, contribui-se para o emprego apropriado deste tipo de material, além de complementar informações técnicas pouco disponíveis no mercado. Além disso, os dados medidos em campo podem servir de validação para modelagem computacional para uma variação maior de ângulos, e na avaliação de ambientes projetados ou construídos, os dados coletados, em especial os ângulos diferentes da incidência normal, podem ser usados em simulação energética ao longo do ano. / This research focuses on the evaluation of solar and optical performance of metal sheets with different patterns of perforations used as shading devices in the building\'s envelope. Solar and light transmittance were experimentally tested at normal and off-normal incident angles of samples of perforated metal sheet, expanded metal sheets and perforated tile, with or without painting, flat or volumetric shape. The relationship between % perforation of sample and transmittance for off normal angle incidence (height and azimuth) was evaluated. Solar and optical results were correlated for each sample. Samples with similar characteristics such as perforation, painting, hole dimension were compared. ASTM E 972 Standard Test Method for Solar Photometric Transmittance of Sheet Materials Using Sunlight and ASTM E 1084 Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight were adopted for field measurements of the samples. The results show that for all samples, the solar transmittance (TS) and light (TL) perpendicular to the sample is similar to % perforation; for off normal angles there is a reduction as the solar altitude decreases and that the higher the hole relative to thickness, the smaller the reduction. TS / TL decreases as solar height decreases, except for the tiles. Regarding the change in azimuth for perforated sheets with or without painting, the values of TL and TS remains practically the same, whereas for expanded metal and tiles values vary. For the painted samples, TS and TL bright color of the samples are higher than the intermediate color samples which are in turn higher than the samples of dark colors. From the results achieved and with the development of the application table to diferente incident angles, within the architecture field, these results provide information for the appropriate use of such material, plus some additional technical information available in the market. Furthermore, the data measured in the field can serve as validation for computational modeling to a wider range of angles, and also it could be used in buildings\' energy simulations.
44

Utvärdering av provmetod till säten för fordonsindustrin : Utvärdering och vidareutveckling av ny provmetod inriktat mot ökad hållbarhet på säten vid Volvo Car Group / Evaluation and further development of new test method focusing on increased quality on seats at Volvo Car Group

Thörn, Christopher January 2017 (has links)
Detta examensarbete utfördes på Karlstads universitet i samarbete med Volvo Car Group, en svensk tillverkare av premiumbilar. Arbetet är fokuserat på ett kvalitetsproblem på Volvos produktionslinje då ett tillverkningsfel uppstår när montörer sätter sig i bilarna för att utföra arbetsuppgifter. Detta gäller på andra generationen av XC90 och senare bilmodeller. Ett permanent instegsveck uppstår och återhämtar sig inte när kunden får sin bil levererad. Idag har Volvo inga provmetoder som kan efterlikna problemet och ett arbete sattes igång under 2015 för att komma fram till en ny provmetod. Arbetet fick avslutas mitt i projektet pga. andra prioriteringar, vilket resulterade i en prototyp som behövdes utvärderas vidare för att kunna bli en fullständig provmetod.   Målet för det här examensarbetet var att utvärdera prototypen med hjälp av designprocessen. En förstudie utfördes med fokus på information från det tidigare projektet, nuvarande provmetoder, läderteknik, granskning av sätesdesign, benchmarking och observationer på Volvos bilmodeller direkt från fabriken och ute hos återförsäljare. Efter förstudien påbörjades en utvärdering om prototypen kunde efterlikna problemet mellan Volvos olika varianter av stolar, såsom sportstolar. Genom att betygsätta resultatet med en betygsskala mellan 1–5 var det möjligt att se stor skillnad mellan stolarna med referens från produktion. Andra typer av slitage som nötningsskador uppstod innan det önskade resultatet, speciellt på stolar inriktade på god komfort. På sportstolarna var den avancerade geometrin ett problem att applicera efter provmetodens möjligheter.   Sista delen av projektarbetet utfördes det en bedömning av prototypen baserat på resultatet från mätningarna. Prestandan från prototypen bedöms vara svår att efterskapa på alla typer av stolar. Ett av de större problemen var att få lädret i ett skört tillstånd då prototypen hade en begränsad rörelse. För att projektet skulle fortlöpa så utfördes en kort granskning baserat på erfarenheterna där fokus låg på faktorer som hade påverkat resultatet mest, dessa var rörelse och material. Resultatet för att kunna efterlikna samma instegsveck i produktion är det optimalt med en tryckrörelse på 45° riktat mot sätets sidobolster samt ett mjukt PUR-skum. Detta gav ett optimalt resultat på alla stolar utan att andra slitage uppstod. För att lösa problemet är det nödvändigt för Volvo att titta på två områden, antingen åtgärder inom produktion med extra skydd eller tillämpa konstruktionsändringar i stolarna med en nyutvecklad provmetod som är framtagen på rätt premisser. / This thesis was carried out at Karlstad University and in corporation with Volvo Car Group, a premium car manufacturer from Sweden. The work focuses on a quality problem at the assembly line. A problem occurs on the front seats with the new generation of XC90 and further released car models. It is to Volvo Cars knowledge that an early wear occurs on the leather seats when assemblers ingress and egress the cars during work tasks and the wear then never recovers. To fix this problem and previous work has been carried out at Research & Development in 2015 but was unfortunately required to be held because of other priorities. The previous work resulted in a prototype which purpose was to become a new test method to this issue. However, the prototype needed further investigation to verify if it can replicate the early wear like the seats at the assembly line.   The goal of the research was to evaluate the prototype with a theory based on Engineering Design Process. A pre-study was performed focusing on collecting data from the previous project, current test methods, leather technology, seat design, benchmarking as well as an excursion of Volvo’s lineup of cars at the assembly line and dealerships. After the pre study, a measurement task was performed with the variety of different seat design. This was done to evaluate whether the prototype met the requested requirements or not. By grading the result with a number between 1-5 it was possible to see a difference between the seat design and to replicate the wear problem. Other attritional wear would occur before the desired outcome of wear, especially on comfort seats. It was hard to apply the sports seat to the benefits of the prototype because of the more advanced design.   The last part consisted of an assessment on the prototype and was based on its performance. The results show that the prototype does have a problem to replicate the wear and isn’t applicable on all available seats. One of the main issues was to get the leather in a brittle state based on the movement from the prototype. Furthermore, a short research was carried out on in-depth knowledge of this work to gain an understanding and cognition for continued work. For replicate the requested wear a pressure movement was required at a 45° angle and aimed to the seat side bolster with a soft polyurethane foam. It shows successfully results at every kind of seat design. To solve this issue it’s necessary for Volvo to consider precautions at the assembly line or changes in seat design with a newly developed test method based on the right premises.
45

joining polycarbonate – manufacturing and evaluation of transparent joints using an innovative objective test method: joining polycarbonate–manufacturing and evaluation of transparent joints using an innovative objective test method

Hofmann, Karoline 05 December 2017 (has links)
Large-scale laminated safety glass is increasingly used in the public and private sector for example museums, jewelers or villas. Special safety is provided by these glasses in layered combination with polycarbonate sheets. Due to the low weight and its high tensile elongation comparing glass of the same thickness, highly transparent polycarbonate is suitable for safety-relevant components. Because of the dimensional limitation in the extrusion process, joining polycarbonate compounds are necessary for large-area joint of this laminated safety glass. According to the present state of the art, a transparent weld joint of polycarbonate is not possible. Within the scope of the project, polycarbonate joints were produced by infrared welding and adhesive bonding. The transparency of the joints was realized by varying the process parameters, for example the heating time. Additionally the present study focusses on a new innovative light intensity measurement, because conventional optical test methods can only subjectively assess the transparency and quality of the compound and the welding seam. The principle is based on the transmission of the welded and polished polycarbonate sample by means of a laser and the measurement of the current at the connected photoelectric cell, which is proportional to the intensity of the laserlight. This enables a qualitative evaluation of the joining dimension and -quality such as structural changes over the entire sample width. The results of this objective method correlate with the width of the stress distribution around the joining level, which are made visible with the photoelasticity using a polariscope and thus contribute to a better process understanding.
46

Development of a Particle Flow Test for Rotational Molding

Whatcott, Russell B. 30 June 2008 (has links) (PDF)
One of the current testing method (the Dry Flow test) to qualify resin for use in production in the rotomolding process has been shown to have many flaws in both equipment and procedure. Research was done here to investigate a possible alternative that could eliminate some of these testing deficiencies. By reducing equipment and operator errors, the testing of materials becomes more valuable of an exercise. The Angular Flow test developed in this research can increase repeatability. By coming to understand the rotational molding process better, an evaluation that can give more valid information was devised.
47

Development of Dynamic Test Method and Optimisation of Hybrid Carbon Fibre B-pillar

Johansson, Emil, Lindmark, Markus January 2017 (has links)
The strive for lower fuel consumption and downsizing in the automotive industry has led to the use of alternative high performance materials, such as fibre composites. Designing chassis components with composite materials require accurate simulation models in order to capture the behaviour in car crashes. By simplifying the development process of a B-pillar with a new dynamic test method, composite material products could reach the market faster. The setup has to predict a cars side impact crash performance by only testing the B-pillar in a component based environment. The new dynamic test method with more realistic behaviour gives a better estimation of how the B-pillar, and therefore the car, will perform in a full-scale car side impact test. With the new improved tool for the development process, the search for a lighter product with better crash worthiness is done by optimising a steel carbon fibre hybrid structure in the B-pillar. The optimisation includes different carbon fibre materials, composite laminate lay-up and stiffness analysis. By upgrading simulation models with new material and adhesive representation physical prototypes could be built to verify the results. Finally the manufactured steel carbon fibre hybrid B-pillar prototypes were tested in the developed dynamic test method for a comparison to the steel B-pillar. The hybrid B-pillars perform better than the reference steel B-pillar in the dynamic tests also being considerably lighter. As a final result a hybrid B-pillar is developed that will decrease fuel consumption and meet the requirements of any standardized side impact crash test. / Strävan efter lägre bränsleförbrukning och minimalistiskt tänkande inom bilindustrin har lett till användning av alternativa högpresterande material, såsom fiberkompositer. Vid design av chassi-komponenter utav kompositer krävs noggranna simuleringsmodeller för att fånga upp bilens beteende vid en krock. Genom att förenkla utvecklingsprocessen för en B-stolpe med en ny dynamisk testmetod kan produkter bestående av fiberkompositer nå marknaden snabbare. Provuppställningen skall förutse bilens prestanda vid ett sidokrocktest genom att endast testa B-stolpen i en komponentbaserad miljö. Den nya dynamiska testmetoden med ett mer realistiskt beteende skall ge en bättre uppskattning om hur B-stolpen, och därmed bilen, kommer att prestera i ett fullskaligt sidokrocktest. Med utvecklingsprocessens nya förbättrade verktyg kan strävan mot lättare produkter med bättre krocksäkerhet utvecklas genom optimering av en hybrid B-stolpe i stål och kolfiber. Optimeringen innefattar olika kolfibermaterial, laminatvarianter och styvhetsanalyser. Genom att uppgradera simuleringsmodeller med nya material och adhesiva metoder kunde fysiska prototyper tillverkas för att verifiera resultaten. Slutligen testades de tillverkade prototyperna utav stål och kolfiber i den nyutvecklade dynamiska testmetoden för jämförelse mot den ursprungliga stål B-stolpen. Hybrid B-stolparna presterade bättre än referensstolpen utav stål i de dynamiska provningarna och är samtidigt betydligt lättare. Det slutgiltigt resultatet är en utvecklad hybrid B-stolpe som både ger minskad bränsleförbrukningen och uppfyller kraven för ett standardiserat sidokrocktest.
48

Capturing JUnit Behavior into Static Programs : Static Testing Framework

Siddiqui, Asher January 2010 (has links)
<p>In this research paper, it evaluates the benefits achievable from static testing framework by analyzing and transforming the <em>JUnit3.8 </em>source code and static execution of transformed code. Static structure enables us to analyze the code statically during creation and execution of test cases. The concept of research is by now well established in static analysis and testing development. The research approach is also increasingly affecting the static testing process and such research oriented work has proved particularly valuable for those of us who want to understand the reflective behavior of <em>JUnit3.8 Framework</em>.</p><p><em> JUnit3.8 Framework</em> uses <em>Java Reflection API</em> to invoke core functionality (test cases creation and execution) dynamically. However, <em>Java Reflection API</em> allows developers to access and modify structure and behavior of a program.  Reflection provides flexible solution for creating test cases and controlling the execution of test cases. Java reflection helps to encapsulate test cases in a single object representing the test suite. It also helps to associate each test method with a test object. Where reflection is a powerful tool to perform potential operations, on the other hand, it limits static analysis. Static analysis tools often cannot work effectively with reflection.</p><p>In order to avoid the reflection, <em>Static Testing Framework</em> provides a static platform to analyze the <em>JUnit3.8</em> source code and transform it into non-reflective version that emulates the dynamic behavior of <em>JUnit3.8</em>. The transformed source code has possible leverage to replace reflection with static code and does same things in an execution environment of <em>Static Testing Framework</em> that reflection does in <em>JUnit3.8</em>. More besides, the transformed code also enables execution environment of <em>Static Testing Framework</em> to run test methods statically. In order to measure the degree of efficiency, the implemented tool is evaluated. The evaluation of <em>Static Testing Framework</em> draws results for different Java projects and these statistical data is compared with <em>JUnit3.8</em> results to measure the effectiveness of <em>Static Testing Framework</em>. As a result of evaluation, <em>STF</em> can be used for static creation and execution of test cases up to <em>JUnit3.8</em> where test cases are not creating within a test class and where real definition of constructors is not required. These problems can be dealt as future work by introducing a middle layer to execute test fixtures for each test method and by generating test classes as per real definition of constructors.</p>
49

Bestimmung der Wärmeleitfähigkeit von nichtdurchströmten zellularen Metallen

Skibina, Valeria 05 February 2013 (has links) (PDF)
Zellulare metallische Strukturen zeichnen sich durch ihre hohe Porosität und ihre komplexe geometrische Struktur aus. Dadurch ist die Bestimmung ihrer Wärmeleitfähigkeit eine komplizierte und aufwändige Messaufgabe. Für die vorliegende Arbeit wurden Materialien ausgewählt, die sich im Grundmaterial, in der Herstellungsmethode und im strukturellen Aufbau unterscheiden. Dabei wurden Materialien mit unterschiedlicher Porosität und Porengröße untersucht. Die effektive Wärmeleitfähigkeit wurde mit drei unterschiedlichen Messverfahren bestimmt. Die Messungen wurden bei normalem Druck bei Raumtemperatur und für ausgewählte Materialien bis maximal 800 °C durchgeführt. Dabei wurden die Bedingungen für die optimale Durchführung der Messungen und die Probleme jedes Verfahrens herausgearbeitet. Daraus wurden Empfehlungen für die optimale Messungsdurchführung abgeleitet. Die gewonnenen Messergebnisse wurden miteinander, mit Werten aus der Literatur und mit vorhandenen mathematischen Modellen verglichen.
50

Capturing JUnit Behavior into Static Programs : Static Testing Framework

Siddiqui, Asher January 2010 (has links)
In this research paper, it evaluates the benefits achievable from static testing framework by analyzing and transforming the JUnit3.8 source code and static execution of transformed code. Static structure enables us to analyze the code statically during creation and execution of test cases. The concept of research is by now well established in static analysis and testing development. The research approach is also increasingly affecting the static testing process and such research oriented work has proved particularly valuable for those of us who want to understand the reflective behavior of JUnit3.8 Framework. JUnit3.8 Framework uses Java Reflection API to invoke core functionality (test cases creation and execution) dynamically. However, Java Reflection API allows developers to access and modify structure and behavior of a program.  Reflection provides flexible solution for creating test cases and controlling the execution of test cases. Java reflection helps to encapsulate test cases in a single object representing the test suite. It also helps to associate each test method with a test object. Where reflection is a powerful tool to perform potential operations, on the other hand, it limits static analysis. Static analysis tools often cannot work effectively with reflection. In order to avoid the reflection, Static Testing Framework provides a static platform to analyze the JUnit3.8 source code and transform it into non-reflective version that emulates the dynamic behavior of JUnit3.8. The transformed source code has possible leverage to replace reflection with static code and does same things in an execution environment of Static Testing Framework that reflection does in JUnit3.8. More besides, the transformed code also enables execution environment of Static Testing Framework to run test methods statically. In order to measure the degree of efficiency, the implemented tool is evaluated. The evaluation of Static Testing Framework draws results for different Java projects and these statistical data is compared with JUnit3.8 results to measure the effectiveness of Static Testing Framework. As a result of evaluation, STF can be used for static creation and execution of test cases up to JUnit3.8 where test cases are not creating within a test class and where real definition of constructors is not required. These problems can be dealt as future work by introducing a middle layer to execute test fixtures for each test method and by generating test classes as per real definition of constructors.

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