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1
Macdonald, Niall Patrick. "Microsystems manufacturing technologies for pharmaceutical toxicity testing". Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/5070/.
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To meet the demands of political, ethical and scientific pressures on animal testing, research into possible alternatives is required. Data obtained with animal models often cannot be related to humans. Testing with current cell-based assays, microdosing and pharmacokinetic models contribute to reducing animal testing and improving the drug development process. Micro-fabrication and rapid prototyping techniques offer potential solutions to reduce the need for animal toxicity testing. The aim of this research was to develop biological platforms for in vitro toxicity testing to provide physiologically relevant, high-throughput solutions to reduce animal testing. This was achieved by investigating and integrating microfabrication methods of microfluidics, dielectrophoresis and additive manufacturing. Three approaches were taken: (i) micro-pattern protein arrays for primary hepatocyte cell culture enclosed within microfluidics devices for high-throughput toxicity testing. It was observed that hepatocytes attached to the micro-pattern within microfluidics and maintained viability, however liver specific functions observed by florescence assays, the P450 enzymes, were observed to be reduced compared to Petri dish conditions. (ii) A biomimetic dielectrophoretic cell patterning technique to form liver lobule-like tissue structures within agar on a paper substrate was developed for toxicity testing. Observation of these biomimetic micro liver structures showed high viability (80-90%) and an increase in liver specific function marker albumin protein (20%) compared to control samples after 48 hours. (iii) Rapid prototyping methods were explored with regard to fabrication of microfluidic chips for the automated trapping, imaging and analysis of zebrafish embryos. Monolithic microfluidic chips for zebrafish were developed to be suitable for optical based toxicity assays. The biocompatibility of 3D printed materials was investigated. A method to render the photopolymer Dreve Fototec 7150 compatible with zebrafish culture was observed to provide 100% viability. Future development of this research will aim to (i) develop the liver lobule-like system to use layers of multiple cell types to form complex micro-liver models using additive manufactured microfluidic systems for toxicity testing. (ii) Automation of zebrafish handing using additive manufactured microfluidic devices for in-situ analysis of dechorionated zebrafish for high-throughput toxicity studies.
2
Nelson, Erik Tighe 1964. "Optimizing product testing in the electronics manufacturing industry". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/34706.
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Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics; in conjunction with the Leaders for Manufacturing Program, Massachusetts Institute of Technology, 2000.Also available online at the MIT Theses Online homepage
Includes bibliographical references (p. 103).
This thesis provides insight into methods for data analysis of testing procedures to optimize the overall testing times within the electronics manufacturing industry. By analyzing each test regime within the manufacturing sequence individually, with the goal of overall test time reduction, better test system optimization may occur. Specifically, within Burn In testing it was found that failure rates were heavily dependent upon the device on/off cycle. Once discovered new test cycles were proposed to reduce overall test times by 50%. Once implemented such new test cycles increased early failure capture as expected. In addition, industry benchmarking studies showed new forms of testing such as Highly Accelerated Stress Testing (HAST) are pushing the product testing earlier into the product life cycle where in-process tests such as Burn In may be reduced. In the case of HAST testing, the tests are being conducted in the design phase reducing more costly Burn In testing in the production phase.
by Erik Tighe Nelson.
S.M.
3
Lee, Dai Gil. "Manufacturing and testing of composite machine tool structures". Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15265.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Vita.
Includes bibliographical references.
by Dai Gil Lee.
Ph.D.
4
Shin, SangJoon 1967. "Design, manufacturing, and testing of an active twist rotor". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/49684.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1999.Includes bibliographical references (p. 153-156).
An Active Twist Rotor (ATR) is developed for future implementation of the individual blade control for vibration and noise reduction in helicopters. The rotor blade is integrally twisted by direct strain actuation using active fiber composites (AFC). In order to design and analyze an active blade, a general framework is proposed. A multi-cell thin-walled active composite beam model is developed. The model is validated against a combination of other theoretical models and experimental data. Actuation trend studies are conducted by examining the formulation, and the results are verified by numerical examples. Design requirements are proposed by combining general ones applicable to passive model-scaled rotor blade and specific ones to the current ATR blade. A design flowchart is established for the current design task of the ATR blade since it enables systematic handling of a number of the parameters. Several different concepts of ATR candidates are suggested, and compared with each other with regard to the requirements. Other design aspects such as manufacturing simplicity and cost-effectiveness are also considered in the process. The final design is selected, and final adjustments are added to it in order to simplify its manufacturing. A prototype blade is manufactured in accordance with the final design. A couple of testing articles are fabricated in advance to the full-span prototype in order to debug the manufacturing process. Various tests are conducted with the testing articles and the final prototype to verify the design and correlate with model predictions. A maximum static tip twist of 1.5' (peak-to-peak) was achieved at half of the designed operating electric field before five of the 24 AFC packs failed. Electrical breakdown of the embedded active material caused degradation of twist actuation in the prototype blade, and the causes are presently under investigation. The ATR prototype blade is leading to a complete fully-articulated four-blade active twist rotor system for future wind tunnel tests.
by SangJoon Shin.
S.M.
5
D'Souza, Sachin. "Testing the intelligent machining workstation". Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1038407081.
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6
Iranmanesh, H. "Design and evaluation of on-line magnetic testing systems". Thesis, Cardiff University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359482.
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7
Areir, Milad. "Development of 3D printed flexible supercapacitors : design, manufacturing, and testing". Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16659.
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The development of energy storage devices has represented a significant technological challenge for the past few years. Electrochemical double-layer capacitors (EDLCs), also named as supercapacitors, are a likely competitor for alternative energy storage because of their low-cost, high power density, and high fast charge/discharge rate. The recent development of EDLCs requires them to be lightweight and flexible. There are many fabrication techniques used to manufacture flexible EDLCs, and these methods can include pre-treatment to ensure more efficient penetration of activated carbon (AC) patterns onto the substrate, or those that utilise masks for the definitions of patterns on substrates. However, these methods are inconvenient for building cost-effective devices. Therefore, it was necessary to find a suitable process to reduce the steps of manufacture and to be able to print multiple materials uniformly. This research work describes the first use of a 3D printing technology to produce flexible EDLCs for energy storage. In this research work, the four essential elements for the EDLCs substrate, current collector, activated electrode, and gel electrolyte were investigated. The AC powder was milled by ball milling to optimise the paste deposition and the electrochemical performance. A flexible composite EDLC was designed and manufactured by 3D printing. The electrochemical performance of the flexible composite EDLCs was then examined. Being highly flexible is one of the critical demands for the recent development of EDLCs. Therefore, highly flexible EDLCs were designed and manufactured by only one single extrusion process. The 3D highly flexible EDLC maintains significant electrochemical performance under a mechanical bending test. To meet the power and energy requirements, the EDLCs were connected and tested in series and parallel circuits. A supercapacitor based on printed AC material displays an area specific capacitance of 1.48 F/cm2 at the scan rate of 20 mV/s. The coulombic efficiency for the flexible EDLC was found to be 59.91%, and the cycling stability was achieved to be 56% after 500 cycles. These findings indicate that 3D printing technology may be increasingly used to develop more sophisticated flexible wearable electronic devices.
8
Mannella, Nikolas E. "Design, Manufacturing, and Testing of a Pilot Wet Electrostatic Precipitator". Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1492558871480272.
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9
Al-Khazali, Hisham Ahmad Humadi. "Application of modal testing methods in rotating machinery". Thesis, Kingston University, 2012. http://eprints.kingston.ac.uk/25256/.
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The experimental and analytical modal analysis is used to establish a system modelling methodology in rotating structures, which subsequently can help in design and development of rotating machinery. The purpose of the study is to develop and use modal testing and vibration analysis which would involve obtaining the mathematical model of the system from the test data and subsequently obtaining the unbalanced parameters. The research work includes the application of modal testing method in rotor rig to investigate different modal parameters and detect the behaviour and performance of rotating machinery. This method would be capable of solving many of the related rotating machine problems, such as in turbine and compressor. Unbalance is one of the problems which exist in rotating machinery. Balancing is usually an expensive and laborious procedure and a balancing system would be beneficial for rotor dynamic systems and power generation applications. Excess vibration can cause noise, cyclic stress and wear in machinery. It is important to identify all the critical speeds within the range of operation and analyse the damping effect, mass unbalance and other phenomena in rotating machinery and their effects in their safe operation. These will be investigated in this study. There are several phenomena associated with rotating machinery such as centrifugal and gyroscopic forces which would create complexity in the mathematical procedures in modal analysis that they need to be addressed and interpreted appropriately before they could be used in modal testing of rotating machinery. The experimental technique used in this thesis to obtain the modal and dynamic response properties of structures. This technique has been applied to rotating structures, however the full implementation of modal testing in rotating structures and the implications are not fully understood. and are therefore in need of further investigations. In this study the Frequency Response Function (FRF) data obtained from the specific experimental results are curve-fitted by theoretical data regenerated from overall statistical analysis of measured data. Different excitation methods are used in experiment (hammer and shaker). For hammer test, transient signal is produced. While for shaker test, different vibration signals are produced (Sine, Random and Burst Random). In shaker test, a special frame was designed and used around a plain bearing and the accelerometers were attached to the outer surface of the bearing to measure the response of the lateral motion on several points of the shaft. The excitation force with help of push' rod was generated and applied to the shaft. This method can help to solve the problem in the attachment of shaker and force transducers to the rotor system. The analysis of vibration suppression with different locations and configurations of the unbalanced masses and effect of the adding of balance masses to suppress the vibration amplitude has been studied properly. The experimental results were used for verification of Finite Element (FE) models, since it has good capability for eigen analysis and also good graphical facility. 3-D models result in large number of nodes and elements. This project demonstrates how to extract a plane 2-D model from the 3-D model that can be used with fewer nodes and elements with no loss in accuracy of the results. Transient orbit analysis in the literature indicates that the bearing stiffness and damping affects the vibration amplitude. In this project the study of the effects on the bearing reaction forces and cyclic. bending stress will be investigated. It is envisaged that the approach is not limited to the condition diagnosis and predictive failure but could help the designers to have better understanding of rotor performance at the system design stage. The experimental data are used to characterise the dynamic behaviour of the system and introduce to the correction unbalance to suppress the excess vibration. The experimental data are also used to generate the FE models and subsequently calculate the dynamic reaction forces in the bearings and the cyclic bending stress.
10
Egbert, Derek W. "Testing Guidelines for New Product Development". BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2529.
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While many literary sources outline the product development process, few make mention of the prototyping and testing stage. This thesis suggests that because of its importance in the product development process, "Testing" should be documented as a major step and not just listed as a side note. As part of the testing step, it is suggested that standardized, in-use, and market tests be used to properly evaluate a product. While many rely solely on standardized tests to validate their products, effective in-use tests can be another vital tool that can prove the performance of the product in more specific and relevant applications. In-use tests are a major focus in this thesis and the process of developing and using these in-use tests is explored. A case study is used to prove that effective product development will follow the outlined testing procedure. Also, it shows that in-use testing, combined with other types of testing, can be a vital tool to ensuring the successful launch of a newly developed product. As a result of the case study, the traditional new product development process is amended and a set of guidelines are proposed for use in constructing a successful testing methodology for the new product development process.
11
Hassan, Mohd Roshdi. "Design, manufacturing and testing of SMA-based smart and cellular structures". Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434620.
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12
Sahoo, Debashis 1976. "Manufacturing and testing of an active compressor blade for aeroelastic studies". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9239.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Also available online at the MIT Theses Online homepage
Includes bibliographical references (p. 145-146).
This thesis deals with the manufacture of a 26-bladed 'active' rotor that will be used for developing an experimental database on turbomachinery aeroservoelastic phenomena, such as flutter and its control. The active rotor has blades made of two stress-bearing composite spars, aerodynamically shaped foam, piezoelectric actuators attached to the spar base and a root which allows the blade to be inserted into the rotor. The thesis analyzed the models developed for the active rotor blade design from previous studies and made suitable refinements in them. The following parameters were obtained - spar dimensions, their location and material, piezoelectric dimensions and material, foam material, and root structure and material. Next, technologies were developed for manufacturing the root and the twisted spar, packaging the piezoelectric actuators using copper-Kapton and bonding them to the spars, and wiring the spars and actuators. However, further investigation is necessary with regards to the issues of foam shaping, spar-foam attachment, and development of accurate leading and trailing edges of the blade. The final step involved testing the blade before and after spar-foam bonding. This required testing on the benchtop to obtain the blade performance limitations, and then testing it in vacuum while spinning inside a spin pit, which was constructed for this purpose. The latter gives the blade performance under rotation. The scope of the thesis is limited to the benchtop tests conducted on the active wired spars. Some of the blade and spin pit wiring issues need to be resolved before conducting the spin tests in vacuum. Also a rotor frame incorporating 26 active blades needs to developed to test under vacuum and in a wind tunnel. The results of the preliminary benchtop tests as well as the blade finite element model predict that the blade performance would be lower than the initial target. Several ways of improving its actuation capability considered were: (a) applying higher voltage with DC offset to the actuators, (b) using multi-wafer actuators, and (c) using active fiber composites. However, these issues need further work. The active rotor, when completed, will serve as a robust tool for aeroservoelastic testing over a significantly larger operating range than is currently possible.
by Debashis Sahoo.
S.M.
13
Devlin, William J. "U.S. reliance on foreign sources in missile special test equipment manufacturing". Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA245974.
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Thesis (M.S. in Management)--Naval Postgraduate School, December 1990.Thesis Advisor(s): McCaffrey, Martin J. Second Reader: Doyle, Richard B. "December 1990." Description based on title screen as viewed on March 29, 2010. DTIC Identifier(s): Special Test Equipment, Guided Missiles, Foreign Sourcing, Theses. Author(s) subject terms: Special Test Equipment, Foreign Sourcing. Includes bibliographical references (p. 72-76). Also available in print.
14
Mastbergen, Daniel Blair. "Simulation and Testing of Resin Infusion Manufacturing Processes for Large Composite Structures". Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/mastbergen/MastbergenD0805.pdf.
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The use of composite materials in large primary structures such as wind turbine blades and boat hulls has dramatically increased in recent years. As these structures get larger, new manufacturing processes are required to make them possible. Larger parts also require more expensive tooling, and a higher cost for scrapped parts. This may prohibit the trial and error approach that has been used for many years. The need for accurate process modeling in the design of tooling is becoming essential. Unfortunately, as the processes become more complex so do the models. Although there are several potential processes capable of producing very large parts (10 m - 50 m), they all have one common feature. In order to alleviate the problem of forcing the resin to flow large distances though the fabric, they use a distribution system to spread the resin over the surface of the part. The resin then flows a substantially shorter distance between the channels or through the thickness. The goal of this work was to develop a modeling technique that could accurately model these processes, yet not so complex as to loose its utility. In this study, the flows through the different regions of the mold are examined individually. These regions include the injection system, the distribution channel, and the fabric. The governing equations for each region are then combined to form a comprehensive model that accounts for the flow through each region simultaneously. A series of tests were conducted to verify the models of the individual components, as well as the comprehensive model. The rate limiting step through the fabric was also examined in detail. The model correlated well with the experiments performed, and revealed critical information about these types of processes. A major conclusion is that an accurate and straightforward model can be created for large scale processes, using the small scale bench tests performed in this study. Also, the governing equations developed here from Darcy flow and Stokes flow aid in understanding how the scaling of key parameters affects the process as a whole. Variations in the geometry of the channel, the fabric thickness and fabric properties such as permeability and compressibility can be accounted for in the model.
15
Dickson, Thomas E. "Design, manufacturing and testing of hoop wound tubular in-plane shear specimens". Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/6590.
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High performance fibre reinforced polymer composite materials have become popular replacements for many traditional materials. Unfortunately, some of the methods used to determine composite material properties have not developed as quickly. In particular, there are presently more than ten different test methods used to determine in-plane shear properties. Many of these methods are criticized for their inability to produce a pure shear state in the test region. Tubular in-plane shear specimens, however, are generally accepted as the only specimens which do (at least theoretically) produce a pure shear state. In this study, design, manufacturing and testing procedures were developed for tubular in-plane shear specimens. A specimen was designed which included a thin-walled composite tube and an internal tapered bonded end fitting. In the manufacturing study, techniques were developed to fabricate a tube of excellent quality with high geometrical tolerances. Tubular in-plane shear specimens were then tested and the results compared to test results for three of the most popular tests in use today, namely, the $90\sp\circ$ Iosipescu, $10\sp\circ$ off-axis and $\pm$45$\sp\circ$ tensile in-plane shear test methods. The four tests were compared on the basis of their respective shear states and on their ability to produce shear modulus values which could be used to predict the tensile modulus of shear-sensitive laminates. Results indicate that, though the tubular shear specimens produce the most consistent state of pure shear, they do not accurately predict the tensile moduli of actual laminates. Of the five laminates tested, the $\pm$45$\sp\circ$ tensile shear test best predicted the tensile modulus of four laminates and was next best for the remaining laminate. It was found that as laminate shear sensitivity decreased, the suitability of different test methods changed.
16
McKinniss, Tamera L. "Stress in the workplace : a comparison of stress, coping, and strain levels among manufacturing personnel". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1020190.
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Osipow and Spokane (1984) developed a model which divides occupational stress into the three main areas of stress, coping, and strain. In the past, this model has been empirically tested by the Occupational Stress Inventory (081). However, the Occupational Stress Inventory - Revised (OSI-R) has recently been developed in order to include some of the more recent developments in occupational stress literature. In addition to the original scales of the OSI, the OSI-R also contains five new experimental scales. The present study used the OSI-R to investigate differences in scale scores among management, trade/skilled, and direct labor personnel in two manufacturing plants. Although significant differences were found on the Role Insufficiency, Responsibility and Family Instrumental Support scales, the findings of this study should be questioned due to the unacceptable reliability levels on many of the OSI-R scales.Department of Psychological Science
17
Mdletshe, Zamavangeli. "Design and manufacturing of a temperature controlled chamber for a tensile testing machine". Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2570.
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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017.Material testing is an important test to researchers in material science fields and other engineering related fields. This is the base for material evaluation prior to the application. This test is used in the engineering field to determine the strength of materials which is an aspect of assigning materials to different functions. The uniaxial tensile testing of material is the most common form of testing the strength of metallic material - usually to investigate whether or not the material is worthy of the intended application. Material testing is normally performed under uncontrolled conditions in most laboratories. Numerous attempts had been previously made in attempt to control the temperature conditions when performing the tensile test on special materials such as shape memory alloys (SMA) and other smart materials. Various methods had been employed to control the temperature during tensile testing, methods such as induction heating, warm liquid baths, etc. The aim of this study was to develop a temperature controlled environment for the Houndsfield tensile testing machine which is found at the Cape Peninsula University of Technology in the Mechanical Engineering Department workshop. This was achieved through designing and manufacturing of a thermally controlled chamber -better known as a furnace. This chamber was tested for the optimal combination of proportional, integral and derivative parameters which were tuned on the proportional integral derivative (PID) controller. Performing the tensile test under controlled thermal conditions will allow the analysis of SMAs and other materials behaviour at different temperatures. With the aid of the manufactured chamber, the superior features of the SMA will be able to be studied. The manufactured thermal chamber which is electrically powered is insulated with a special ceramic refractory material to prevent the heat from escaping the chamber. The PID controller was used to control the temperature and heating elements act as the heat source. The manufactured chamber could withstand the maximum temperature 350oC that it was initially designed for. However, the challenge of having the specimen to be tested fully inside the chamber was overcame by designing specimen connectors that connected the specimen to the tensile testing machine. Tensile tests were conducted on the SMA wire at room temperature and other various controlled temperatures and different behaviours were observed on the stress-strain graphs.
18
Sahin, Emre. "Conceptual Design, Testing And Manufacturing Of An Industrial Type Electro-hydraulic Vacuum Sweeper". Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613747/index.pdf.
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CONCEPTUAL DESIGN, TESTING AND MANUFACTURING OF AN INDUSTRIAL TYPE ELECTRO-HYDRAULIC VACUUM SWEEPER
SAHIN, Emre
M.Sc., Department of Mechanical Engineering
Supervisor : Prof. Dr. Kahraman ALBAYRAK
Co-Supervisor: Prof. Dr. Bilgin KAFTANOGLU
September 2011, 156 pages
In this thesis, conceptual design, testing, development and manufacturing processes of the cleaning (elevator and fan system) and electro-hydraulic systems of an industrial type vacuum sweeper are presented. Thesis is financially supported by Ministry of Science, Industry and Technology (Turkey) and Müsan A.S. (Makina Ü
retim Sanayi ve Ticaret A.S.) under the SAN-TEZ projects with numbers 00028.STZ.2007-1 and 00623.STZ.2010-1. The main purpose is to make critical design changes on existing fan system, designing a new elevator system and eventually obtaining efficient and powerful cleaning system. For design, Catia and SolidWorks softwares are used. Within the SAN-TEZ project, all CFD solutions were provided by Punto Engineering. Unlike many industrial type vacuum sweepers, new design will be electrically and electro-hydraulic controlled. All cleaning system of new &lsquo
MÜ
SAN Vacuum Sweeper&rsquo
will be activated by using hydraulic motors (traction system including hydraulic system is driven by the brushless DC electric motor as well) and the power of all these systems is supplied by batteries which are placed in the middle of the vehicle. Elevator and fan system can be considered as a group for a street sweeper for cleaning operations. Fan and elevator systems both gain an important place especially in cleaning operations due to lifting heavy and small particles from the ground. Fan system is used for sucking the small materials and dust by vacuum and elevator system is used to elevate heavier materials such stones, bottles, cans. Therefore, it is essential to design an efficient and powerful fan and elevator system for a street sweeper. The thesis work includes the design, development, supervision of manufacturing, simulation and testing of the cleaning (elevator and fan systems) and electro-hydraulic system of the street cleaners.
19
Ma, Weitao. "Cost modelling for manufacturing of aerospace composites". Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/6279.
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The application of composites has been increasing dramatically in aerospace structures recently, for example, composites have contributed over 50 percent of the structure mass of large transport airplanes Boeing 787 and Airbus 350XWB. However, the further usage has been restricted because of the high material and manufacturing costs. Hence, it is essential to utilize cost estimation tools for accurate cost estimation in the early design stages, and then efficient decisions and design optimizations could be made to reduce the cost of composite products. This research project aims to develop a cost model for aerospace carbon fibre reinforced plastic (CFRP) composites, which will help designers and cost engineers with the cost estimation for composites manufacturing in the early development stages. The main objectives of the research are to: (i) recognise the standard manufacturing stages and activities of CFRP components; (ii) identify the cost drivers of composites manufacturing; (iii) identify the cost estimation relationships; (iv) develop a cost model that can assist designers and engineers with manufacturing cost estimation for CFRP components; (v) validate the developed cost model through case studies and expert judgements. The process of model development was carried out through four main steps: firstly, conducting an integrated understanding of cost modelling for composites manufacturing; secondly, collecting data for cost modelling from industry and existing literature and databases; thirdly, developing the cost model with several function modules and databases; and finally, taking a validation of the developed model. The developed cost model consists of several modules: material selection, process planning, cost estimation, cost reporting and a user friendly interface. Moreover, the selection and planning modules are combined with databases including material and process. The developed model enables the user to estimate the manufacturing cost and process time of CFRP composites, and it can also help designers realize the impact of design changes on the manufacturing cost. The process planning can efficiently help estimators with manufacturing process understanding and accurate time estimation. Quality control activities are time consuming and investment sensitive in composites manufacturing.
20
Evans, Thomas C. (Thomas Carl) 1971. "Statistical usage models in mobile processor thermal design and testing". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89389.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; in conjunction with the Leaders for Manufacturing Program at MIT, 2003.Includes bibliographical references (p. 77).
by Thomas C. Evans.
S.M.
21
Sim, Lay M. "Design, manufacturing and testing of smart beams with EFPI strain sensor for damage detection". Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/13207.
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This thesis aimed at the development of a fibre optic strain sensor-based damage detection and evaluation system (FODDAS) based on the composite beams. EFPI strain sensors were used with their integrity being assessed. Their performance, either bonded on the surfaces or embedded was examined extensively. They were shown to be adequate and reliable for strain measurements. Through-the-width damages were simulated by artificially-embedded delaminations, which were located at several through-the-thickness locations, each with two different sizes. The overall design considerations were guided by ply stresses and strains which were estimated by using the modified classical lamination theory (CLT). Considerable efforts were devoted to assessing the through-the-thickness mechanical behaviours of the beams containing optical fibres in three-point bending and short beam shear (SBS). They involved various optical fibre orientations with respect to 00 plies / longitudinal axis and at various through-the-thickness locations, each with different number of optical fibres. The understanding of these behaviours paved the way for the evaluation of the beam-based FODDAS. Smart preconditioned beams were subjected to the quasi -static loads whose magnitudes and locations were required to be well controlled. The viability and effectiveness of the beam-based FODDAS was evaluated in terms of strength and strain obtained by the embedded sensor as well as the surface-bonded strain gauges via the cross comparison of ten cases. For the strength, each beam was incrementally loaded up to the ultimate failure either in three-point bending or SBS. After each increment, the beam was unloaded and inspected for damage. For the given locations of EFPI-SS and artificial delamination as well as the sizes of the latter, it was found that the embedded EFPI-SSs were capable of picking up the stiffness degradation when the 10- mm as well as the 20-mm delamination was located at the 29-30 ply interface in the tensile region of a 32-ply quasi-isotropic carbon/epoxy smart composite beam. It was speculated from single tests results that the propagation of the embedded delamination of the sufficient size was able not only to be detected but also to be monitored by the sensors.
22
Katch, Sebastien F. (Sebastien Ferderick) 1975. "Concept development, mechanical design, manufacturing and experimental testing for a cannon-launched reconnaissance vehicle". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9574.
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23
Krishnamurthy, Kasthuri Rangan. "Application of HTML/VRML to Manufacturing Systems Engineering". Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31031.
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Manufacturing systems are complex entities comprised of people, processes, products, information systems and data, material processing, handling, and storage systems. Because of this complexity, systems must be modeled using a variety of views and modeling formalisms. In order to design and analyze manufacturing systems, the multiple views and models often need to be considered simultaneously. However, no single tool or computing environment currently exists that allows this to be done in an efficient and intelligible manner. New tools such as HTML and VRML present a promising approach for tackling these problems. They make possible environments where the different models can coexist and where mapping/linking between the models can be achieved. This research is concerned with developing a hybrid HTML/VRML environment for manufacturing systems modeling and analysis. Experiment was performed to compare this hybrid-modeling HTML/VRML environment to the traditional database environment in order to answer typical design/analysis questions associated with manufacturing systems, and to establish the potential advantages of this approach. Analyzing results obtained from the experiment indicated that the HTML/VRML approach might result in better understanding of a manufacturing system than the traditional database approach.Master of Science
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Korhonen, E. (Esa). "On-chip testing of A/D and D/A converters:static linearity testing without statistically known stimulus". Doctoral thesis, University of Oulu, 2010. http://urn.fi/urn:isbn:9789514263064.
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Abstract
The static linearity testing of analog-to-digital and digital-to-analog converters (ADCs and DACs) has traditionally required test instruments with higher linearity and resolution than that of the device under test. In this thesis ways to test converters without expensive precision instruments are studied. A novel calculation algorithm for the ADC differential non-linearity (DNL) and integral non-linearity (INL) estimation is proposed. The algorithm assumes that two stimuli with constant offset between them are applied to the ADC under test and that the code density histograms for both stimuli are recorded. The probability density function (PDF) of the stimulus is then solved using simple calculations so that DNL and INL of the ADC can be estimated without a priori known stimuli. If a DAC is used to generate the stimulus to ADC, all inputs and outputs are digital and the new algorithm can be used to obtain the PDF of the DAC output. Moreover, the PDF of DAC actually characterizes its INL and DNL so that this all-digital test configuration enables a simultaneous testing of both converters thanks to the new algorithm.
The proposed algorithm is analyzed thoroughly both mathematically and by carrying out several simulations and experimental tests. On the basis of the analysis it is possible to approximate the impending estimation error and select the optimal value for the offset between the stimuli. In theory, the accuracy of the algorithm proposed equals that of the standard histogram method with ideal stimulus, but in practice, the accuracy is limited by that of the offset between the stimuli. Therefore, special attention is paid to development of an accurate and small offset generator which enables ratiometric test setup and solves the problems in the case of reference voltage drift. The proposed on-chip offset generator is built using only four resistors and switches. It occupies 122·22 μm2 in a 130 nm CMOS process and accuracy is appropriate for the INL testing of 12-bit converters from rail-to-rail. Based on the analysis of the influence of resistor non-linearity on the accuracy of offset, it is possible to improve the offset generator further. With discrete resistors, the INL of 16-bit ADCs was tested using a 12-bit signal generator.
The proposed simple algorithm and tiny offset generator are considered to be important steps towards built-in DNL and INL testing of ADCs and DACs.
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Drivas, Thanos. "Manufacturing Three-dimensional Carbon-fibre Preforms for Aerospace Composites". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31577.
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Carbon fibre reinforced polymer matrix composites (CF PMCs) are increasingly used in state-of-the-art aerospace applications. Aerospace manufacturers favour components made of CF PMCs over those made of traditional metallic alloys because of their light weight and corrosion resistance, which lead to significant improvements in fuel consump- tion, increased payload capability, and reduced maintenance and inspection costs. How- ever, manufacturing of CF PMC components is performed differently than traditional material in all stages – design, prototyping and production – and therefore, many com- mercial manufacturers have only recently begun producing components with CF PMCs.
The first half of this thesis was written as a contribution to the CRIAQ COMP-501 project, which focusses on investigating the cost-effective procurement of airframe com- ponents that are manufactured from final-thickness, net-shaped, and through-thickness reinforced CF preforms. Reinforcement preforms were assembled from commercial 2D woven fabric using stacks of various configurations of structural through-thickness CF stitch. The contribution herein provides the results obtained from investigations into the mechanical behaviour of the relevant reinforcements, when subjected to pre-infusion op- erations typical to RTM VARTM; mechanical behaviour in compaction, shear (draping) and bending (forming).
The second half of this thesis presents the major developments which were made to an alternative process for producing thick 3D preforms with great versatility, a process originally proposed as a candidate for supplying preforms to the COMP-501 project. This process interfaces a proprietary kinematic drape optimization (CAD) software with proprietary automated dry fibre placement assembly (CAM) machinery to produce vari- able or final-thickness reinforcements which are highly-drapable and can lay steered tow yarns.
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Dorsey, David Michael. "Estimating the expected latency to failure due to manufacturing defects". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/202.
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Manufacturers of digital circuits test their products to find defective parts so they are not sold to customers. Despite extensive testing, some of their products that are defective pass the testing process. To combat this problem, manufacturers have developed a metric called defective part level. This metric measures the percentage of parts that passed the testing that are actually defective. While this is useful for the manufacturer, the customer would like to know how long it will take for a manufacturing defect to affect circuit operation. In order for a defect to be detected during circuit operation, it must be excited and observed at the same time. This research shows the correlation between defect detection during automatic test pattern generation (ATPG) testing and normal operation for both combinational and sequential circuits. This information is then used to formulate a mathematical model to predict the expected latency to failure due to manufacturing defects.
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Walew, Daniel. "Application of Lean Methods in Product Development Testing : A Case Study from the Manufacturing Industry". Thesis, KTH, Industriell Management, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-124631.
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A broad research foundation exists on Lean management in the manufacturing context. Furthermore, the implementation of Lean in product development is discussed by an increasing number of publications. Yet, little documentation of the specific application in product development testing has been published. This master thesis provides insights into the specific environment of product development testing and the application of Lean methods. Utilizing a systematic literature research, the beginning of this work elaborates principles of case study research, the context of testing as part of product development and the Lean management framework. The findings are synthesized into a priori construct for the case research. Main pillar for this construct is the value stream mapping method. It combines the analysis of the current state, the development of the future state and a strategy for the implementation of improvements. Central part of this thesis is the in-depth case study of a global operating manufacturing company in the off-highway machinery market. Three product development testing sites were visited by the author in order to apply the previously defined case study framework. Through cross case analysis common process characteristics of the current state are derived. From a micro level perspective the relations within and across the testing process are shown. Needs, values, wastes, interruptions and other process parameters are systematically analyzed; improvements are elaborated and prioritized to develop a common future state for the testing process. A partial takt time driven test process could be developed. To visualize the process task boards were introduced and the value stream map was digitalized and connected to a management information system. The systematic understanding of information needs is a major part of the future state. A possible implementation strategy is presented in this thesis.
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de, Caussin Dylan Robert. "Design and Testing of a Top Mask Projection Ceramic Stereolithography System for Ceramic Part Manufacturing". DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1625.
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Ceramic manufacturing is an expensive process with long lead times between
the initial design and final manufactured part. This limits the use of ceramic as a viable material unless there is a large project budget or high production volume associated with the part. Ceramic stereolithography is an alternative to producing low cost parts through the mixing of a photo curable resin and ceramic particles. This is an additive manufacturing process in which each layer is built upon the previous to produce a green body that can be sintered for a fully dense ceramic part.
This thesis introduces a new approach to ceramic stereolithography with a top mask projection light source which is much more economical compared to current vector scanning methods. The research goes through the design and development of a stereolithography printer prototype capable of handling ceramics and the testing of different mixtures to provide the best printing results with varying viscosities. The initial testing of this printer has created a starting point for top mask projection as an economical alternative to current ceramic manufacturing techniques.
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Bhadauria, Anubha Singh. "Production lead time reduction in a semiconductor capital equipment manufacturing plant through optimized testing protocols". Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93841.
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Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (page 63).
Processes at a semiconductor equipment manufacturing facility were studied with the goal to reduce the production lead time. Based on the principles of lean manufacturing, DMAIC methodology was used to guide the process. Value Stream Mapping (VSM) of the whole process was done to determine that the Universal End Station (UES) was the module with the longest lead time. This work focuses on the optimization of the testing process on the UES. Time studies were conducted for the assembly and test of the UES module and analysis of results revealed a testing process that is serial and thus of a very long duration. Further investigations revealed that some of the processes required the test technician to do manual calibrations and measurements which resulted in long test times. Based on the interviews with involved personnel, historical data analysis and the research carried out, specific tests were recommended for automated testing and parallel testing. A decision tree was developed to help aid in the selection of the suitable candidates for automation while a dependency network diagram was developed to aid in selection of candidates for parallel testing. It is projected that these recommendations will reduce the Testing lead time of UES by 8.4% and labor hours by 16.3%. Keywords: Lean manufacturing, semiconductor, optimization, bottle neck, lead time, DMAIC, Value Stream Mapping, Time study, Root cause analysis.
by Anubha Singh Bhadauria.
M. Eng. in Manufacturing
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Thibodeau, Alexis. "3D-Printed Surrogate Lower Limb for Testing Ankle-Foot Orthoses". Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42755.
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Traditionally, the mechanical testing of ankle-foot orthoses (AFOs) has been performed with simple limb surrogates, typically with a single axis ankle joint and rigid foot and shank components. Since many current AFO designs allow 3D motion, a surrogate lower limb (SLL) that provides anatomically similar motion in all planes is needed to enable realistic load testing and cyclic testing in a controlled manner. The aim of this thesis was to design, fabricate and test a novel SLL that provides anatomically realistic 3D foot motion, based on a consensus of the passive lower limb range of motion (RoM) found in the literature.
The SLL design was inspired by the Rizzoli model, sectioning the lower limb into five segments (shank, hindfoot, midfoot, forefoot, toes). Ball and socket joints were used for the shank-hindfoot, hindfoot-midfoot, and midfoot-forefoot. Forefoot-toes used a hinge-type joint. 3D printed flexible thermoplastic polyurethane (TPU) snap-fit connectors connected the 3D printed nylon foot blocks. A threaded ball stud connected the shank shaft and hindfoot. This shank shaft was surrounded by a 3D printed polylactic acid (PLA) shank cover. The foot was cast in silicone rubber to emulate soft tissue, with a PLA custom mould based on a Össur prosthetic foot cover model.
The SLL was successfully designed for easy fabrication using readily available techniques, materials, and components. Only the metal shaft required additional machining. 3D printed components used an affordable 3D printer (Artillery Sidewinder X1), and readily available nylon, PLA, and TPU.
Using motion capture testing, SLL foot rotation angles were found to be within standard deviation of mean foot passive rotation angle ranges found in the literature, showing that most joints were within 5° of target maximum rotation angles. With load testing, the SLL was shown to survive static loads representing 1.5 times body weight for a 100 kg individuals and cyclic loads representing normal gait loading for 500,000 cycles.
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Grippo, Christian P. (Christian Patrick) 1969. "Design and manufacturing of a tensile text machine for in-situ atomic force microscope mechanical testing". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89386.
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Armstrong, Isaac W. "Development and Testing of Additively Manufactured Aerospike Nozzles for Small Satellite Propulsion". DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7428.
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Automatic altitude compensation has been a holy grail of rocket propulsion for decades. Current state-of-the-art bell nozzles see large performance decreases at low altitudes, limiting rocket designs, shrinking payloads, and overall increasing costs. Aerospike nozzles are an old idea from the 1960’s that provide superior altitude-compensating performance and enhanced performance in vacuum, but have survivability issues that have stopped their application in satellite propulsion systems. A growing need for CubeSat propulsion systems provides the impetus to study aerospike nozzles in this application. This study built two aerospike nozzles using modern 3D metal printing techniques to test aerospikes at a size small enough to be potentially used on a CubeSat. Results indicated promising in-space performance, but further testing to determine thermal limits is deemed necessary.
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Esterly, Daniel Mason. "Manufacturing of Poly(vinylidene fluoride) and Evaluation of its Mechanical Properties". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34677.
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Poly(vinylidene fluoride) (PVDF) receives an increasing amount of attention because it exhibits the strongest piezoelectric response of any commercially available polymer. These piezoelectric properties have proved useful as actuators and sensors. Current manufacturing processes limit PVDF to thin films and restricting their uses largely to sensors. Further applications utilizing the changes in mechanical properties of piezoelectric polymers are being realized. Evaluating to what extent the mechanical properties will change with applied electric field and finding new ways to manufacture PVDF will lead to new applications of piezoelectric polymers.
In-situ mechanical testing of biased piezoelectric PVDF films successfully measured changes in loss and storage modulus. In-situ creep testing measured an increase in stiffness while in-situ dynamic mechanical analysis (DMA) measured and overall decrease in loss and storage modulus. Differences in results between the two experiments are attributed to orientation of the polymer and piezoelectric forces acting on the equipment. DMA results are accepted as being the most accurate and measured changes of over 20% in elastic modulus. Results were believed to be greatly influence by attached electrodes and actuation forces.
Cryogenic mechanical milling successfully converted a phase PVDF powder to b phase as measured with wide-angle x-ray diffraction. This is the first recorded instance of b phase powders forming from the a phase through ball milling. These b phase powders maintained their crystal structure during compression molding at 70°C.Master of Science
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Perini, Francesco. "Structural design, manufacturing and testing of the new wing for the CSIR's Modular UAS in composite materials". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4772/.
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In the framework of an international collaboration with South Africa CSIR, the structural design, manufacturing and testing of the new wing for the Modular UAS in composite materials has been performed.
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Knudsen, David Charles 1972. "Application of stastical quality control to improve yields and rationalize testing in a low volume manufacturing facility". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/84228.
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Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (p. 71).
by David Charles Knudsen.
S.M.
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Dalal, Malay A. "An object-oriented simulation-based method for emulation development for testing shop control software". Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-06062008-151722/.
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Haney, Christopher Willard. "Fabrication and Testing of Biomimetic Microstructures for Walkway Tribometers". Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1609174/.
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The main objective of this work is to give contribution in both additive manufacturing (AM) and tribometry derived from the application and study of materials available with the use of biomimetic designs. Additional contributions are determining what effects treatments for flooring surfaces may have on the dynamic coefficient of friction and the effects of these products on common surfaces. The validity of the proposed methodology for a proof of concept was demonstrated by comparing measured dynamic coefficient of friction for designs using standardized equipment and comparing these values to plantar skin tested using an accepted and standardized testing method that has been extensively researched and validated. Initial biomimetic designs and characteristics unique to each design were researched and compared. Eleven designs were selected to be fabricated, tested, and compared to select the most desirable applications for further investigation. Research into potential treatments commercially available for use was done to determine the efficacy of these products. Prototype sensor designs were selected and fabricated using direct light processing (DLP) technology. Examination of the measured values was done through an analysis of the variances in the response variable and comparisons using Fisher and Tukey pairwise comparison method. Future work recommendations are provided for further development and improvement of the topics presented in this thesis.
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Strand, Henrik. "Design, testing and analysis of journal bearings for construction equipment". Doctoral thesis, Stockholm : Department of Machine Design, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-429.
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Williams, Thomas Joseph. "Testing the Atlantic ice hypothesis : the blade manufacturing of Clovis, Solutrean and the broader technological aspects of production in the Upper Palaeolithic". Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/16685.
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The origins of Clovis technology and the nature and timing of the first populations to reach the Western Hemisphere is one of the most contentious issues in American archaeology. With the rejection of “Clovis-first”, many scholars consider that all colonising migrations followed a route out of Asia and across Beringia into North America. However, none of the technologies present in the far northeast of Asia or Beringia exhibit the manufacturing processes that were used in Clovis. To address this enigma, Stanford and Bradley proposed a radical alternative for the origins of Clovis. They argue that a small pioneering group of Solutreans crossed the Atlantic ice sheets of the LGM and reached the shores of North America. The basis for this argument stems from technological similarities between Clovis and the Solutrean, as well as from climatic, oceanographic, and ethnographic data. Biface manufacture is at the centre of their technological analysis, specifically comparing the reduction sequences of the distinctive Solutrean laurel leaf points and comparing them to Clovis points. This thesis tests the assumption of Stanford and Bradley that the blade manufacturing technologies of Clovis and Solutrean were “virtually identical”. By analysing the blade manufacturing processes from the Solutrean assemblage at Laugerie-Haute and the Clovis assemblage from the Gault site and comparing them to the broader technological patterns present across Eurasia between ~30,000 BP and 11,000 BP; this thesis supports the findings of Stanford and Bradley with the amendment that Clovis specifically intended to produce curved blades but did not use blades to produce projectile points. While convergence cannot be completely ruled out, there is a lack of evidence that would explain the number of similarities in the manufacturing processes. Thus it remains highly likely that interaction across the ice-edge corridor of the Atlantic may have occurred during the LGM.
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Sharif, Tahir. "Robotic approach to low-cost manufacturing of 3D preforms with dry fibres". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/robotic-approach-to-lowcost-manufacturing-of-3d-preforms-with-dry-fibres(d25f48b9-0d9e-4d78-a2dd-e00da1d127c7).html.
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High-performance fibres such as carbon, glass and kevlar are very promising for aerospace applications because of their high strength, stiffness, impact damage and excellent fatigue life. The high cost of the prepreg materials such as pre-impregnated fibre tape/tow and fabrics, and limitations of existing manufacturing processes are a big challenge for the aerospace industry to meet increasing performance demands. Their benefits can only be achieved by using low cost materials and manufacturing methods. In the past three or four decades, there have been substantial technological developments, which are governed by the new materials and their associated manufacturing techniques. The production of carbon fibre is slow and capital intensive, therefore, carbon manufactures produce higher tow counts (number of filaments) to increase production through-put in order to reduce its cost. In other words, 12k carbon tow is much cheaper than 6k or 3k carbon tow. In many applications finer tows are desirable. In this thesis, a fully automated laser feedback tow splitting line has been developed to split higher tow counts (12k spool) into smaller tow counts (split into 6k spools) in order to produce low cost material. The quality of the split tows has been evaluated by recording the data online during the splitting process. The recorded data was later analysed by statistical tools. A four axis modular gantry robotic system has been developed at the University of Manchester in order to deposit dry fibres in a completely flexible manner. To facilitate robotic preforming, an end-effector and mould have been designed and developed in this research. The tow placement program was written in the CoDeSys software which is then uploaded into the motion controller to perform specific motions. The cross-ply laminates have been manufactured by the proposed robotic system using split 6k (produced by the tow splitting process) and original 12k carbon tows. Mechanical test of both composites (12k and split 6k) are presented. A tufting process has been developed and conducted by the robotic system in order to manufacture 3D preforms. The tufted composite was compared with 3D woven and stitched 2D broadcloth in terms of the tensile and interlaminar shear strength properties. X-ray tomography has been conducted to investigate preform geometrical variations of manufactured composites. In addition, preforming cost models have been developed for robotic fibre placement and 3D weaving.
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Balding, Alan Guy. "A case study on the implementation of prevalence testing for HIV in a manufacturing company in Kwazulu-Natal". Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50235.
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Thesis (MPhil)--Stellenbosch University, 2005.On t.p.: HIV/AIDS Management.
ENGLISH ABSTRACT: This article describes the approach taken by a company to successfully implement prevalence testing for HIV at one of its manufacturing sites in KwaZulu-Natal. Ninety point four percent of the employees on site on the day of testing subjected themselves to voluntary anonymous testing. No rewards or incentives whatsoever were offered or given to the participants. The problem faced by the company was that there was increasing mortality amongst its employees, particularly those in the lower job grades, mainly machine operators and other lesser skilled positions. The cost of insured benefits provided by the company’s provident fund for death and disability were increasing and less money could be allocated to funding for retirement. In the absence of any empirical data the company had no idea how they would be affected by the HIV/AIDS pandemic, other than attempting to use provincial averages. The level of knowledge of HIV and AIDS in the company was judged as relatively poor. Many of the staff, more so the senior staff, had little or no exposure to the disease and what effect it had on those suffering from it or those supporting sufferers. Little had been achieved to manage HIV and AIDS until a workshop was organised by the company for representatives from all branches to attend. Various information topics about HIV were covered at the workshop, which concluded with the site representatives having to work out and table an action plan, and make a personal pledge of what they were going to do to help in the fight against HIV and AIDS. The workshop was attended by all board members, senior management, shop stewards and shop floor representatives. One of the key features of the presentations was by a senior official of the union, who then assisted throughout the rest of the workshop. Site plans were then later followed up when a central committee visited the sites and presentations on progress were made.At the workshop mention was made of the need to conduct prevalence testing and also the establishment of a HIV/AIDS committee. The site committee made the decision that prevalence testing should take place and consulted the workforce themselves and also through shop stewards. Once it was felt that sufficient support would be forthcoming a date for testing was set. The company had in the meantime contracted with a service provider to do testing where needed. A briefing session attended by the HIV/AIDS committee, shop stewards, the management team and two executive directors was arranged. A doctor employed by the service provider addressed the group and answered their concerns and demonstrated the saliva test on himself. On the day of testing senior management and the senior shop steward walked the factory floor encouraging employees to participate. This intervention has laid the foundation for a successful management campaign against HIV and AIDS in the workplace.
In hierdie artikel word die benadering wat n maatskappy gebruik om die voorkomsyfer van MIV by een van sy vervaardigingsterreine in KwaZulu-Natal to toets, beskryf. Op die dag waarop toetsing plaasgevind het, het 90,4% van die werknemers op die terrain hulleself vrywilliglik laat toets. Tydens hierdie anonieme toetsing is geen belonging of voordele van enige aard aan die deelnemers gebied nie. Die problem wat die maatskappy gehad het, was dat daar n toenemde sterftesyfer onder werknemers in die laer posvlakte soos masjienoperateurs en werknemers in posiese wat minder vaardighede vereis. Daar was stygende koste (in terme van dood en ongeskiktheid) van versekerde voordele waarvoor die maatskappy se voorsieningsfonds voorsiening maak, wat tot gevolg gehad het dat daar minder geld beskikbaar was vir pensionfondse. Omdat daar n tekort van empiriese data was, het die maatskappy geen idée gehad van die effek wat die MIV/VIGS-pandemie op hom sou uitoefen nie, behalwe deur die gebruik van provinsiale gemiddeldes. Die kennis van MIV/VIGS binne die maatskappy is as swak bestempel. ’n Groot hoeleevheid van die personeel, veral die in senior poste, het min of geen blootstelling gehad van die virus en die effek wat dit op VIGS-lyers en die ondersteuners van VIGS-lyers het nie. Min is gedoen on MIV/VIGS te bestuur, totdat n werkswinlek deur die maatskappy georganiseer is vir verteenwoordiges van al, die takke. ’n Verskeidenheid onderwerpe in verband met MIV/VIGS is deur die werkswinkel gedek. Een daarvan was dat die terreinverteenwoordiges n aksieplan moes opstel en n persoonlike eed moes afle dat hulle sou help in die stryd teen MIV/VIGS. Die werkswinkel is deur al die raadslede, senior bestuurslede, werkswinkelassistente en –verteenwoordiges bygewoon. Die hoofsaak van die voorleggings is deur n senior uniebeampte gelei, waarna hy vir die verloop van die program geassisteer het. Terreinplanne is opgestel en dit is later opgevolg deur n sentralle komitee wat die terreine besoek het en voorleggings gelewer het in verband met die vordering wat gemaak is. Tydens die werkswinkel is melding gemaak van die noodsaaklikheid van die toetsing van die voorkomsyfers van MIV en die instelling van n MIV/VIGS komitee. Die terreinkomitee het besluit dat die voorkomstoetsing moes plaasvind nadat die werkersmag en werkswinkelsttistente gekonsulteer is. Nadat besluit is dat die nodige ondersteuning uit hierdie toetsing sou voortspruit, is ’n datum vir die toetsing voorgestel. Vir die interementydperk het die maatskappy ’n diensverskaffer gekontrak om die toetsing, waar nodig, waar te neem. ’n Inligtingsessie is gereel wat deur die MIV/VIGS-komitee, werkswinkelassistente, die bestuurspan en twee uitvoerende direkteure bygewoon is. ’n Dokter, wat deur die diensverskaffer in diens geneem is, het die groep te word gestaan en antwoorde verskaf op hulle vraagstukke. Hy het ook die speekselftoets op himself gedemonstreer. Op die dag wat die toetsing plaasgevind het, het die seniorbestuur en werkswinkel-assistant deur die fabriek geloop en werknemers anngemoedig on aan die toetsing deel te neem. Hierdie intervensie het gelei tot die stigting van n suksesvolle bestuursveldtog teen MIV/VIGS in die werksplek.
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Wojtowicz, Maria. "Macro composites for crushing - additive manufacturing of hard phase : Development and testing of macro composites for crushing purposes". Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447459.
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During this master thesis a crushing material composite was developed in order to determine if a specific design consisting of a pointy hard phase with a ductile phase in between can reduce the load needed to crush stone and therefor decrease the energy consumption during stone crushing. The steel hard phase (ASP 2012) was printed using an additive manufacturing method called selective laser melting (SLM). A process parameter optimization was performed in order to achieve a dense material and a pre-heated building platform was used to prevent cracking. The hard phase designs were printed and then filled with bronze (JM3 and JM7). The composites and steel references were tested by placing a stone on each sample and applying pressure until the stone broke. After the tests, the loads and the deterioration of the samples was analyzed. The results showed that it was possible to print the hard phase, but some defects like micro cracking were hard to eliminate entirely. Several methods were tested to cast the bronze but the most suitable during this project was melting of the bronze in an induction furnace with vacuum atmosphere. The results from the crushing simulations showed that there was a small difference between the references and the developed macro composites. The composites began to crush stones at lower loads than the references. Nevertheless, due to a large dispersion of the results a statistical difference could not be established.
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Friedman, Alex Matthew. "An Approach to Incorporate Additive Manufacturing and Rapid Prototype Testing for Aircraft Conceptual Design to Improve MDO Effectiveness". Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/73656.
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The primary objectives of this work are two-fold. First, additive manufacturing (AM) and rapid prototype (RP) testing are evaluated for use in production of a wind tunnel (WT) models. Second, an approach was developed to incorporate stability and control (SandC) WT data into aircraft conceptual design multidisciplinary design optimization (MDO). Both objectives are evaluated in terms of data quality, time, and cost.
FDM(TM) and PolyJet AM processes were used for model production at low cost and time. Several models from a representative tailless configuration, ICE 101, were printed and evaluated for strength, cost and time of production. Furthermore, a NACA 0012 model with 20% chord flap was manufactured. Both models were tested in the Virginia Tech (VT) Open-Jet WT for force and moment acquisition. A 1/15th scale ICE 101 model was prepared for manufacturing, but limits of FDM(TM) technology were identified for production.
An approach using WT data was adapted from traditional surrogate-based optimization (SBO), which uses computational fluid dynamics (CFD) for data generation. Split-plot experimental designs were developed for analysis of the WT SBO strategy using historical data and for WT testing of the NACA 0012. Limitations of the VT Open-Jet WT resulted in a process that was not fully effective for a MDO environment. However, resolution of ICE 101 AM challenges and higher quality data from a closed-section WT should result in a fully effective approach to incorporate AM and RP testing in an aircraft conceptual design MDO.Master of Science
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Sangle, Sagar Dilip. "Design and Testing of Scalable 3D-Printed Cellular Structures Optimized for Energy Absorption". Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1495467365594915.
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Bocken, Nancy Maria Petronella. "Reducing CO₂ emissions associated with fast moving consumer goods : development and testing of tools and frameworks". Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610070.
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Scholz, Tamera Lee. "Pneumoniacheck: a device for sampling lower airway aerosols". Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41175.
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The pathogens causing pneumonia are difficult to identify because a high quality specimen from the lower lung is difficult to obtain. A specimen collection device, named the PneumoniaCheck, was previously designed to collect aerosol specimens selectively from the lower lung generated during deep coughing to aid in the diagnosis of specific pathogens causing pneumonia. The device also includes several specially designed features to exclude oral contaminants from the sample, and a filter to collect the aerosolized pathogens. The objective of this thesis is to develop tests to verify the functionality of the device, called the Design Inputs.
Nine verification tests were performed to demonstrate the ability to collect lower airway aerosols separate from upper airway aerosols, successful exclusion of oral contents, and capture of pathogens in the filter. Further, the PneumoniaCheck was tested for proper sampling of the lower airway aerosols during deep cough at a very low volumetric flow rate to simulate patients with severe restrictive lung disease and with mal-positioning to simulate incorrect patient placement.
Verification testing of the PneumoniaCheck demonstrates effective separation of upper airway gas from the lower airway gas (p<0.0001) and exclusion of both liquid and viscous oral material (p<0.0001) from the collection chamber. Testing also demonstrated the selective sampling of the lower airway, even during low volumetric flow rates or incorrect positioning of the device.
The complex shape of the PneumoniaCheck presents a manufacturing challenge. Making the device from a solid and then drilling out the tubes would be difficult because the outer channels do not align with the inner channel. Rapid prototyping, vacuum molding, and injection molding are all manufacturing options. Rapid prototyping is slow, and usually only economic for small numbers of parts. For vacuum molding or injection molding, the PneumoniaCheck would need to be cut in half and molded, and then the halves connected with fasteners, glued, or welded. Vacuum molding is inexpensive, but there would be a lip at the connection that may be uncomfortable for patients. If the lip is on the inside of the device, it may interrupt air flow through the device. Injection molding is inexpensive and fast. The PneumoniaCheck could be injection molded in halves, and then glued or sonically welded together. Injection molding would be an efficient and economical way to manufacture the device.
Verification tests were developed and performed, and the results demonstrate that the PneumoniaCheck successfully collects lower airway aerosols separate from upper airway aerosols, excludes oral contents, and captures pathogens in the filter, even during non-ideal conditions. After considering three different manufacturing options, injection molding was recommended for the device.
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Guo, Jianglong. "Numerical and experimental study of electroadhesion to enable manufacturing automation". Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/21718.
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Robotics and autonomous systems (RAS) have great potential to propel the world to future growth. Electroadhesion is a promising and potentially revolutionising material handling technology for manufacturing automation applications. There is, however, a lack of an in-depth understanding of this electrostatic adhesion phenomenon based on a confident electroadhesive pad design, manufacture, and testing platform and procedure. This Ph.D. research endeavours to obtain a more comprehensive understanding of electroadhesion based on an extensive literature review, theoretical modelling, electrostatic simulation, and experimental validation based on a repeatable pad design, manufacture, and testing platform and procedure.
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Lillington, Richard. "Fuel system characterization : an investigation into the effects associated with the manufacturing and testing of precision fuel system components". Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/58445/.
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Every sub-component of a diesel injector must perform optimally to ensure maximum fuel economy and minimum particulate and carbon-dioxide emissions. Continually developing emissions standards will drive manufacturers to guarantee fuel system performance for a significant period of the unit lifetime. Key to implementing such systems will be the ability to compensate for unit changes in use. This thesis investigates possibilities for developing existing unit and sub-component characterization techniques to enable robust performance over an extended duration. An overview of existing injector characterization techniques is given, along with possibilities for enhancement of the existing state of the art through development of measurement systems widely used within the industry. Particular attention is paid to developing methods to allow testing of injectors and sub-components under representative conditions, where system pressures of 3000 bar are commonplace. Consideration is given to the benefits of moving from existing methods, based on steady-state testing, towards dynamic transfer function testing, and methods reliant on real-time sub-system feedback, to enable better characterization of the unit in use. Key to the development of enhanced characterization will be feedback from the electrohydraulic valves operating inside the injector. These valves are critical to current heavyduty injector designs. To enable full understanding of the unit’s operation, the thesis develops mathematical representations of such component’s functionality. Software models of these systems are offered, and various model simulations discussed. Possibilities for refining these are also provided. Within this thesis the available mechanisms for taking valve position feedback measurements capable of detecting valve lifts of <30 μm with suitable resolution and accuracy are discussed. The results of experiments with various sensing devices are then presented. Subsequently, novel methods for taking measurements using the unit stator as a sensing element are developed, described in terms of mathematical models, and tested in software simulations. Sensing experiments using valve hardware are then described. The thesis closes with a discussion on important future trends in fuel system development.
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Shabbir, Ali M. Eng Massachusetts Institute of Technology. "Scale-up of a high-technology manufacturing startup : improving product reliability through systematic failure analysis and accelerated life testing". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101334.
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Thesis: M. Eng. in Manufacturing, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 112-115).
Ensuring product reliability is a key driver of success during the scale-up of a high-technology manufacturing startup. Reliability impacts the company image and its financial health, however most manufacturing startups do not have a solid understanding of their product's reliability. The purpose of this thesis is to introduce systematic failure analysis to the engineering design process and to establish a framework for testing and analyzing product life so that imperative business decisions and design improvements could be made with regards to reliability. A detailed study and implementation of these process improvements to address reliability issues was conducted at New Valence Robotics Corporation (NVBOTS) in Boston, Massachusetts. Systematic failure analysis was achieved through the creation and implementation of Failure Modes and Effects Analysis (FMEA) procedures. A single FMEA iteration was performed on the NVPro printer to identify the top risk component-linear ball bushings-for detailed life analysis. Following an in-depth investigation of potential failure modes of the linear bushings, an Accelerated Life Test (ALT) was designed using Design of Experiments (DOE) principles. An accompanying test apparatus with mechatronic control was also designed. The ALT was not actually executed but representative data was analyzed for illustrative purposes using the General Log-Linear (GLL) life-stress relationship and a 2-parameter Weibull distribution for the accelerating stresses of mechanical load and lubrication. The work performed provides NVBOTS and similar high-technology manufacturing startups a complete starting point for systematically analyzing their product's reliability and quantitatively evaluating its life in a resource efficient way.
by Ali Shabbir.
M. Eng. in Manufacturing
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Jorapur, Nikhil Sudhindrarao. "Design, Fabrication and Testing of Fiber-Reinforced Cellular Structures with Tensegrity Behavior using 3D Printed Sand Molds". Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/84531.
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The overall goal of this work is to improve the structural performance of cellular structures in bending applications by incorporating tensegrity behavior using long continuous fibers. The designs are inspired by the hierarchical cellular structure composition present in pomelo fruit and the structural behavior of tensegrity structures. A design method for analyzing and predicting the behavior of the structures is presented. A novel manufacturing method is developed to produce the cellular structures with tensegrity behavior through the combination additive manufacturing and metal casting techniques.
Tensegrity structures provide high stiffness to mass ratio with all the comprising elements experiencing either tension or compression. This research investigates the possibility of integrating tensegrity behavior with cellular structure mechanics and provides a design procedure in this process. The placement of fibers in an octet cellular structure was determined such that tensegrity behavior was achieved. Furthermore, using finite element analysis the bending performance was evaluated and the influence of fibers was measured using the models. The overall decrease in bending stress was 66.6 %. Extending this analysis, a design strategy was established to help designers in selecting fiber diameter based on the dimensions and material properties such that the deflection of the overall structure can be controlled.
This research looks to Additive Manufacturing (AM) as a means to introduce tensegrity behavior in cellular structures. By combining Binder Jetting and metal casting a controlled reliable process is shown to produce aluminum octet-cellular structures with embedded fibers. 3D-printed sand molds embedded with long continuous fibers were used for metal casting. The fabricated structures were then subjected to 4 point bending tests to evaluate the effects of tensegrity behavior on the cellular mechanics. Through this fabrication and testing process, this work addresses the gap of evaluating the performance of tensegrity behavior. The overall strength increase by 30%. The simulation and experimental results were then compared to show the predictability of this process with errors of 2% for octet structures without fibers and 6% for octet structures with fibers.Master of Science