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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.
251

NÁVRH AUTOMATICKÉ PIPETOVACÍ HLAVY NA PRINCIPU PERISTALTICKÉHO ČERPADLA / DESIGN OF AUTOMATIC PIPETTING HEAD ON THE PRINCIPLE OF PERISTALTIC PUMP

Čížek, Petr January 2021 (has links)
The aim of this diploma thesis is to design and create a prototype of automatic pipetting head that will be useful for pipetting in laboratories after attaching it to a robotic manipulator. In the beginning, a research about various types of automatic pipetting heads was made followed by a device design and component analysis. The prototype was made using 3D printing method and it utilises a peristaltic pump, Arduino microcontroller and Bluetooth interface. A measurement of repeatability and dispensing accuracy was made on the finished device. The results are evaluated in the conclusion.
252

3D tisk kovů robotem / 3D metal printing by robot

Tvrdoň, Radek January 2021 (has links)
The diploma thesis presents an overview of additive production technologies and a summary of technologies used for 3D metal printing using a robot. All of them are generally described and at the same time assigned to their specific commercial use, or the academic research that deals with them. The work examines the suitability of the material EN ISO 14341-A: G 3Si1 for 3D printing, for which a modification of the Col Metal Transfer technology, Cycle Step is used. The experimental printout of the sample is evaluated on the basis of surface and mechanical tests. Capillary test, examination of microstructure a macrostructure, tensile test and microhardness test. All of them were satisfactory and the suitability of the welding wire for 3D printing was confirmed by the given technology.
253

Low cost and conformal microwave water-cut sensor for optimizing oil production process

Karimi, Muhammad Akram 08 1900 (has links)
Efficient oil production and refining processes require the precise measurement of water content in oil (i.e., water-cut) which is extracted out of a production well as a byproduct. Traditional water-cut (WC) laboratory measurements are precise, but are incapable of providing real-time information, while recently reported in-line WC sensors (both in research and industry) are usually incapable of sensing the full WC range (0 – 100 %), are bulky, expensive and non-scalable for the variety of pipe sizes used in the oil industry. This work presents a novel implementation of a planar microwave T-resonator for fully non-intrusive in situ WC sensing over the full range of operation, i.e., 0 – 100 %. As opposed to non-planar resonators, the choice of a planar resonator has enabled its direct implementation on the pipe surface using low cost fabrication methods. WC sensors make use of series resonance introduced by a λ/4 open shunt stub placed in the middle of a microstrip line. The detection mechanism is based on the measurement of the T-resonator’s resonance frequency, which varies with the relative percentage of oil and water (due to the difference in their dielectric properties). In order to implement the planar T-resonator based sensor on the curved surface of the pipe, a novel approach of utilizing two ground planes is proposed in this work. The innovative use of dual ground planes makes this sensor scalable to a wide range of pipe sizes present in the oil industry. The design and optimization of this sensor was performed in an electromagnetic Finite Element Method (FEM) solver, i.e., High Frequency Structural Simulator (HFSS) and the dielectric properties of oil, water and their emulsions of different WCs used in the simulation model were measured using a SPEAG-dielectric assessment kit (DAK-12). The simulation results were validated through characterization of fabricated prototypes. Initial rapid prototyping was completed using copper tape, after which a novel reusable 3D-printed mask based fabrication was also successfully implemented, which would resemble screen printing if it were to be implemented in 3D. In order to verify the design’s applicability for the actual scenario of oil wells, where an oil/water mixture is flowing through the pipes, a basic flow loop was constructed in the IMPACT laboratory at KAUST. The dynamic measurements in the flow loop showed that the WC sensor design is also equally applicable for flowing mixtures. The proposed design is capable of sensing the WC with a fine resolution due to its wide sensing range, in the 80 – 190 MHz frequency band. The experimental results for these low cost and conformal WC sensors are promising, and further characterization and optimization of these sensors according to oil field conditions will enable their widespread use in the oil industry.
254

Low-Cost Inkjet-Printed Wireless Sensor Nodes for Environmental and Health Monitoring Applications

Farooqui, Muhammad Fahad 11 1900 (has links)
Increase in population and limited resources have created a growing demand for a futuristic living environment where technology enables the efficient utilization and management of resources in order to increase quality of life. One characteristic of such a society, which is often referred to as a ‘Smart City’, is that the people are well informed about their physiological being as well as the environment around them, which makes them better equipped to handle crisis situations. There is a need, therefore, to develop wireless sensors which can provide early warnings and feedback during calamities such as floods, fires, and industrial leaks, and provide remote health care facilities. For these situations, low-cost sensor nodes with small form factors are required. For this purpose, the use of a low-cost, mass manufacturing technique such as inkjet printing can be beneficial due to its digitally controlled additive nature of depositing material on a variety of substrates. Inkjet printing can permit economical use of material on cheap flexible substrates that allows for the development of miniaturized freeform electronics. This thesis describes how low-cost, inkjet-printed, wireless sensors have been developed for real-time monitoring applications. A 3D buoyant mobile wireless sensor node has been demonstrated that can provide early warnings as well as real-time data for flood monitoring. This disposable paper-based module can communicate while floating in water up to a distance of 50 m, regardless of its orientation in the water. Moreover, fully inkjet-printed sensors have been developed to monitor temperature, humidity and gas levels for wireless environmental monitoring. The sensors are integrated and packaged using 3D inkjet printing technology. Finally, in order to demonstrate the benefits of such wireless sensor systems for health care applications, a low-cost, wearable, wireless sensing system has been developed for chronic wound monitoring. The system called ‘Smart Bandage’ can provide early warnings and long term data for medical diagnoses. These demonstrations show that inkjet printing can enable the development of low-cost wireless sensors that can be dispersed in the environment or worn on the human body to enable an internet of things (IoT), which can facilitate better and safer living.
255

An Investigation of Avian Wing Tip Vortex Generation Using a Biomimetic Approach

Martin, David Stewart 01 June 2017 (has links)
An experimental study has been conducted to develop a process allowing the creation of biologically accurate aerodynamic test models mimicking the slotted primary feather geometry of the Brown Pelican (Pelecanus occidentalis). Preserved examples of both a full Brown Pelican wing and a single primary feather were 3D scanned and digitally reconstructed using a combination of MATLAB and CAD software. The final model was then 3D printed as a collection of smaller components using a LulzBot TAZ 6 printer and Taulman3D T-Glase PET filament. After using various surface finishing techniques to improve the finish of all 3D printed parts, an assembly was designed to mount the model in the low speed wind tunnel at the California Polytechnic State University. Prior to aerodynamic testing, airfoil sections of the pelican wing were generated in CAD and several common airfoil measurements and characteristics were investigated. At a flow velocity of 5 m/s (Re ~1.21 x 105), wind tunnel smoke and laser visualization testing highlighted the vortex generation of multiple primary feathers, as well as large-scale flow deviations in the vicinity of the feathers. A total pressure rake and total pressure probe were used to create detailed plots of the ratio of the local velocity to free-stream velocity (Vx/Vx∞) at two planes downstream of the model, which revealed vortex positioning consistent with that predicted by smoke visualization testing and provided a metric by which to evaluate the relative strength of each vortex. The model creation process and wind tunnel testing results outlined here provide a strong foundation for future investigations into the potential aerodynamic benefits provided by the slotted primary feather geometry employed by the Brown Pelican and other large gliding avian species.
256

SLM 125 Single Track and Density Cube Characterization for 316L Stainless Steel

Goss, Cullen 01 June 2019 (has links)
Selective Laser Melting is a rapidly developing additive manufacturing technique that can be used to create unique metal parts with tailormade properties not possible using traditional manufacturing. To understand the process from a most basic level, this study investigates system capabilities when melting single tracks of material. Individual tracks allow for a wide range of scan speeds and laser powers to be utilized and the melt pools analyzed. I discuss how existing studies and simulations can be used to narrow down the selection of potentially successful parameter combinations as well as the limitations of interpretation for single track information. Once we attain a solid understanding of what parameters perform well at a bead level, we can move onto looking at complete 3D parts. A challenge we have faced is creating near fully dense parts and determining a reliable density measurement technique that is accessible for operators at our university. Our results show that the previously determined optimized scan speed and laser power can consistently create parts with >99.5% density over a range of sizes using an analysis method utilizing readily available equipment and software.
257

Výroba dílů technologií DMLS a jejich porovnání s jinými konvenčními technologiemi z hlediska ekonomické náročnosti / Production of parts by DMLS technology and their comparison with other conventional technologies in terms of economic performance

Sekerka, Vít January 2011 (has links)
This diploma thesis presents a technology based on the gradual smelting of fine layers of metal powder by using a laser beam. It explains and describes basic terminology related to the Rapid Prototyping technology, its division and practical usage. A part of the thesis is also the fabrication of several prototype parts by Direct Metal Laser Sintering including the economical comparison of their fabrication with other conventional technologies.
258

Vliv průměru trysky na kvalitu tisku 3D tiskárny / Effect of the diameter of the nozzle on the 3D printer print quality

Kutil, Jaroslav January 2016 (has links)
The matter of this thesis is to find the influence of the diameter of the nozzle on the 3D printer´s print quality. The first part briefly characterizes the Rapid Prototyping technology and describes the RepRap project. The second part describes the construction of the experimental FMD 3D printer. The following section deals with technical printing parametres and their influence on the printed product. The experimental part of the thesis is focused on the impact of the discharge nozzle diameter on the mechanical properties, surface quality and shape accuracy of the final product and on the following recommendations of operational parametres.
259

Vývoj 3D FDM tiskárny implementace na trh / Development of FDM 3D printer and implementation on the market

Bouchal, Petr January 2016 (has links)
The result of this thesis is to create an overview of available 3D printing technologies, design a 3D FDM printer, create an instructional manual on the assembling and create a business model of a 3D printing company.
260

Využití mobilního telefonu k analýze tekutých vzorků / Use of cell phone in liquids analysis

Křístek, Tomáš January 2016 (has links)
Technological development, broad availability and ubiquity of mobile phones made it possible in recent years to start a progression leading to the integration of mobile phones into biomedical analytical methods, the development of telemedicine and mobile personal health applications. This paper deals with the literature review of the mobile phone usage in biomedicine, with emphasis on the methods of optical analysis and technical solutions using 3D printing technology. It provides a draft and practical implementation of salivary cortiol level measuring system using a mobile phone, ELISA analytical methods, 3D printing technology and a set of custom Matlab functions connected with Matlab Mobile application and Mathworks Cloud. Also provides critical evaluation of results and method possibilities, and presents set of proposals and findings for quality of measurment optimization.

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