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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.
1

Design and Validation of a Wireless Interface for the V-Quest: A Vulvar Quantitative Sensory Testing Device

Mitri, Layla 06 April 2023 (has links)
This thesis presents the design and validation of a wireless interface for a vulvar quantitative sensory testing device (v-QueST). The wireless interface works in tandem with an Android application which allows a patient to indicate when their pressure pain threshold has been reached via an on-screen button. Using the fully assembled prototype, the sampling frequency and response time of the wireless interface was validated. The results indicated that the sampling frequency was sufficient to meet the desired specifications, and the time delay between the tap of the on-screen button and the reading of the force measurement was negligible. However, inspection of the force time-series acquired from the v-QueST device through Bluetooth transmission revealed systematic error. Implementation of a new signal conditioner is recommended before using the v-QueST device for research or clinical applications to objectively measure vulvar pain sensitivity.
2

Design of a Cyclic Sliding, Dynamically Loaded Wear Testing Device for the Evaluation of Total Knee Replacement Materials

Thompson, Matthew Thomas 08 August 2001 (has links)
During normal walking, the relative motion of the human knee involves flexion/extension, anterior/posterior sliding, and medial/lateral rotation. As well, the knee experiences a complex, dynamic loading curve with a peak of up to seven times body weight. However, most wear testing machines that have been used to evaluate total knee replacement materials are unidirectional and/or apply only static force. This thesis presents an alternate wear testing device capable of simulating the most prevalent motions of the knee, and applying physiologically-correct loading to the material interface. By incorporating a CoCr disc, an UHMWPE block, stepping motors, pneumatic components, computer control, and linear tables in an x-y configuration, the device is capable of quickly screening new and alternative materials to UHMWPE before evaluating them on a much more expensive knee simulator. In addition, flexibility of the device allows programming of many different motion and loading configurations permitting materials testing under only certain circumstances, or evaluating the effects on wear of specific motions. Design rationale, development, validation, and future recommendations are presented. / Master of Science
3

Design and development of a testing device for a new invented Doctor Blade

Sadek, Mohamed January 2013 (has links)
This thesis project is about designing and developing an already existing testing device for a new invented Doctor Blade. A doctor blade is a blade used for creping tissue paper of a rotating cylinder, Yankee Cylinder. The old testing device was incomplete in a way that a rotating cylinder was missing, hence the tested blade is not loaded properly. The old testing device already contained the doctor blade holding device and the pulling device (pulling the creping blade). These two devices are transferred to the new testing device without any redesign within them. The adding of a rotating cylinder/roller required some new redesign regarding the testing device. The main beam (beam carrying all elements) is replaced with a larger one in order to fit the roller and is elongated in order to run longer tests. The new beam has a larger cross section in order to minimize the risk of bending. The main beam is supplied with five small beams, welded onto it, three for attaching the holding device and two for attaching the roller. The dimensions of these small beams are chosen in order to put the roller on the right position according to the creping blade. An electric motor is added to the new testing device in order to drive the roller with a chain. This required two sprockets, one for the motor and one for the roller shaft. The sprockets are chosen with a pitch diameter ratio matching the gearing required. FMEA-analysis is done on the whole design where five failure modes were chosen to be included, bending of the main beam and motor beam, screw joints of the same beams and sprocket-chain mechanism. Some FEM-analysis was required in order to detect the bending of the beams and measuring the loading on the screw joints. The screw joint loading achieved from the FEM-analysis is used for the theoretical screw joint calculations. The FMEA-analysis implied that four of the analyzed failure modes have acceptably low risk factor and dos not require any further actions. However one received a high risk factor, the chain-sprocket mechanism, the risk of clamping fingers. This is solved by adding a protecting house/shell made of sheet metal. Measurements were done on the old and the new testing device regarding the required force for pulling the creping blade and the pressure distribution between the creping blade and the beam (and roller in the new testing device). The improvement of the pulling force values is rather due to the new designed doctor blade than due to the new testing device. The new testing device is however more appropriate than the old one hence the added roller and the tests shows that it is functional as well. / Projektet handlar om design och utveckling av en redan existerande testrigg för ett nyuppfunnet kräppningsblad. Ett kräppningsblad är det bladet som just kräpper av papper från en roterande cylinder, s.k. Yankee Cylinder. Den gamla testriggen var inte komplett och saknade en roterande cylinder, därav kräppningsbladet belastades inte ordentligt. Den gamla testriggen innehöll redan en hållaranordning för kräppningsbladet och en dragstation (som drar kräppningsbladet). Dessa två delar förflyttades till den nya testriggen utan några korrigeringar. Tillägget av en roterande cylinder/vals krävde ny design för den nya testriggen. Huvudbalken (balken som bar alla delar) ersattes av en större balk för att den nya valsen ska få plats. Nya balken är även längre i syfte att kunna köra längre tester. Tvärsnittsarean hos den nya balken är större i syfte att minimera risken för böjning. Fem små balkar är fastsvetsade i den nya huvudbalken, tre för fästning av hållaranordningen och två för fästning av valsen. Placeringen av dessa fem balkar valdes i syfte att placera valsen i rätt position enligt kräppningsbladet. En elektrisk motor tillfördes till den nya testriggen i syfte att driva valsen med en kedja. Detta krävde två nya kugghjul, en för motorn och en för valsaxeln. Delningsdiametern för de två kugghjulen valdes med en viss kvot som motsvarar den utväxlingen som krävs. FMEA-analys utfördes på hela testriggen dör fem olika haveriorsaker inkluderades, böjning av huvudbalken och motorbalken, skruvförbanden på dessa två balkar och till sist kugghjul-kedja mekanismen. FEM-analys krävdes för beräkningar av böjningen på balkarne och för belastningen på skruvförbanden. Belastningen på skruvförbanden uppnåd från FEM-analysen användes senare i de teoretiska beräkningarna av skruvförbanden. FMEA-analysen angav att fyra av de fem analyserade haveriorsakerna har accepterad låg riskfaktor och kräver inga åtgärder. Dock så visade det sig att en haveriorsak fick en för hög risk faktor, kugghjul-kedja mekanismen, risken att klämma fingrar.Detta problem löstes med hjälp av att designa ett skyddshus /skal av plåt. Mätningar gjordes på den gamla och den nya testriggen på dragkrafter och tryckfördelning mellan kräppningsblad och balk (vals i den nya testriggen). Förbättringen av värden på dragkrafterna beror mer av det nydesignade kräppningsbladet än av den nya testriggen. Hursomhelst är den nya testriggen lämpligare än den gamla med tanke på tillförseln av valsen och dessutom så visar testerna att den är funktionell.
4

Konstrukční návrh testovacího zařízení pro automobilové zásuvky / Design of low volume inlet tester

Hotový, Michal January 2020 (has links)
The topic of this thesis is the design of a testing device for checking electrical car sockets according customers’ requirements. The electrical socket shall be tested by electrical, mechanical and camera tests. The diploma thesis is divided into two main parts, first is a part describing the basic elements in the construction of electric vehicles, and describing types of electric sockets in electric vehicles, and second, a practical part describing the design of a testing device.
5

Konstrukční návrh testovacího zařízení pneumatických válců / Design of pneumatic cylinder testing equipment

Macek, Tomáš January 2020 (has links)
This diploma thesis deals with the design of test equipment for selected types of pneumatic cylinders. In the first, theoretical, part of the work is an analysis of the current state of knowledge in the field of pneumatic cylinders. Furthermore, the problems in the field of measurement and testing of pneumatic components are described here, selected linear position sensors are also described herein too. The second, practical, part deals with the choice of a suitable design variant and the actual solution of the test equipment design. A pneumatic circuit is also designed here. Part of the work is a 3D model of the test equipment and drawing documentation. The conclusion of the work is devoted to the overall evaluation of the work and recommendations for practice.
6

Konstrukce experimentálního zařízení pro trvanlivostní zkoušky ložisek / Design of experimental device for durability testing of bearings

Frejlich, Tomáš January 2015 (has links)
Diploma thesis deals with the structural design and subsequent implementation of a functional prototype of an experimental device for durability testing of bearings. The first part of the thesis deals with an overview of the current state of knowledge and summarizes information about testing the durability of bearings. In the next part follows the design, selection and analysis of the optimal design variants. The last part deals with the verification of the functionality of the prototype bearing life testing and evaluation of data measured during testing.
7

Mechanické vlastnosti materiálů pro 3D tisk / Mechanical properties of materials for 3D printing

Janiš, Adam January 2021 (has links)
This thesis focuses on the description of 3D printing technologies using the FDM method, which uses deposition of molten thermoplastics and their subsequent cooling and solidification layer by layer. This unique structure then shows a strong anisotropy of mechanical properties and, as a result, their testing and print settings are very important. Tensile testing of plastic materials, including indicators of mechanical properties, are described in this thesis according to ČSN EN ISO standard. The practical part presents the concept of a device capable of performing these tests. The block diagram indicates the functional elements and the connections among them. Tensile strength test is described together with results processing. Necessary product documentation is also included.
8

EMC zkušební laboratoř pro jističe NN / EMC Test laboratory for low voltage circuit breaker

Vejtasa, Leoš January 2014 (has links)
Nowadays there are electronic systems almost in every new device. They are emitting and receiving electromagnetic interferences. The safety levels for circuit breakers are also increasing. Because of these issues the circuit breakers must work properly also in areas filled by electromagnetic interference. This thesis describes the issues of electromagnetic susceptibility of the circuit breakers.
9

Spalování kapalných paliv z obnovitelných zdrojů / Combustion of renewable liquid fuels

Nejezchleb, Radek January 2011 (has links)
This thesis is concerned with combustion of liquid biofuels, and possibility of using liquid biofuels for lower heat output power units. Overview of basic usable liquid biofuels in Czech Republic is executed in the beginning of the thesis. This part is focused especially on production method and energy effectivity of rape-oil methyl ester (RME) and bioethanol production. Overview of basic atomization method of liquid fuels is executed in next chapters. The focus is stressed on pneumatic atomization, especially effervescent atomization method, which was used in practical experiment. Practical part contains fossil fuel and selected biofuel (RME) combustion test executed on burner testing device. Basic combustion properties was found and test plan was made before executing the test. Various operating conditions are compared in terms of atomization quality, combustion quality and geometrical characteristics of flame. Usability of tested liquid biofuels for lower heat output power units is evaluated in the conclusion.
10

Návrh zařízení pro testování a měření ovládacích sil automobilových sedadel / Design of equipment for testing and measurement control forces car seats

Vincenc, Josef January 2013 (has links)
The Master’s thesis deals with development of universal equipment for testing and measurement operating forces of car seats. It describes tests applied on car seats and shows a few examples of equipment for testing. The design part of the thesis deals with development of multipurpose testing equipment using of Modular Function Deployment™ approach. The design of the equipment is done in 5 steps according to mentioned approach. The final part of the thesis includes a risk analysis of the new device and conclusion.

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