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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

Beiträge zu dem Thema: "Über die Strömung der Luft durch Röhren von beliebiger Länge."

Hoffman, Paul, January 1900 (has links)
Inaug.-diss.--Breslau. / Lebenslauf.
2

Stability analysis of a high pressure pneumatic mechanical system

Ford, William Hoyt 08 1900 (has links)
No description available.
3

High velocity circulating fluidized beds

Rhodes, M. J. January 1986 (has links)
No description available.
4

Pneumatic chemistry, 1772-1789 a resolution of conflict /

Langer, Bernard, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
5

Pneumatic ore concentration

Johnson, Robert Winters. Weissbach, Walter William. January 1916 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1916. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed April 2, 2009)
6

Design and control of a pneumatically driven MRI-compatible tele-operated haptic interface

Turkseven, Melih 27 May 2016 (has links)
This study presents methods for understanding, modeling and control of tele-operated pneumatic actuators for rehabilitation in Magnetic Resonance Imaging (MRI). Pneumatic actuators have excellent MRI-compatibility as opposed to conventional electro-mechanical systems; however, the actuator and the system drivers cannot be co-located due to the MRI-compatibility requirements. The actuators are driven via long transmission lines, which affect the system dynamics significantly. Methods provided in this work produced accurate pressure estimation and control by accounting for the pressure dynamics in the lines, which has been neglected by previous work in this area. The effectiveness of the presented modeling and control methods were demonstrated on tele-operation test setups. This research also includes the design of necessary system components for the developed algorithms. An MRI-compatible optical sensor was developed for force feedback and its design was analyzed for high precision. Directions and opportunities for future research are discussed.
7

Development of a Pneumatic Hand Training Device for Stroke Rehabilitation

Jackson, Gregory 16 August 2013 (has links)
A new hand training system has been designed and built to help clinicians administrate hand therapy to stroke patients. It uses pneumatics to actuate the fingers from the dorsal side of the hand in order to provide training for activities of daily living. Before the device is tested in a clinical trial, it’s safety, comfort and reliability needed to be established via trials on 30 healthy individuals. A comfort survey that was issued to the users indicated that they found the device comfortable regardless of age, gender, weight and hand length. The sensor data that was gathered during testing indicated that the readings were reliable and the device had minimal impact on the subjects' normal range of motion. A bio-mechanical model, validated through experimentation, was also created to estimate joint angles of the index finger during the trials to ensure that the device put the joints of the finger in bio-mechanically safe angles. / Natural Sciences and Engineering Research Council of Canada
8

CONTROL OF A PNEUMATIC SYSTEM WITH ADAPTIVE NEURAL NETWORK COMPENSATION

TAGHIZADEH, SASAN 07 October 2010 (has links)
Considerable research has been conducted on the control of pneumatic systems due to their potential as a low-cost, clean, high power-to-weight ratio actuators. However, nonlinearities such as those due to compressibility of air continue to limit their accuracy. Among the nonlinearities in a pneumatic system, friction can have a significant effect on tracking performance, especially in applications that use rodless cylinders which have higher Coulomb friction than rodded cylinders. Compensation for nonlinearities in pneumatic systems has been a popular area of research in pneumatic system control. Most advanced nonlinear control strategies are based on a detailed mathematical model of the system. If a simplified mathematical model is used, then performance is sensitive to uncertainties and parameter variations in the robot. Although they show relatively good results, the requirement for model parameter identification has made these methods difficult to implement. This highlights the need for an adaptive controller that is not based on a mathematical model. The objective of this thesis was to design and evaluate a position and velocity controller for application to a pneumatic gantry robot. An Adaptive Neural Network (ANN) structure was implemented as both a controller and as a compensator. The implemented ANN had online training as this was considered to be the algorithm that had the greatest potential to enhance the performance of the pneumatic system. One axis of the robot was used to obtain results for the cases of velocity and position control. Seven different velocity controllers were tested and their performance compared. For position control, only two controllers were examined: conventional PID and PID with an ANN Compensator (ANNC). The position controllers were tuned for step changes in the setpoint. Their performance was evaluated as applied to sinusoid tracking. It was shown that the addition of ANN as a compensator could improve the performance of both position and velocity control. For position control, the ANNC improved the tracking performance by over 20%. Although performance was better than with conventional PID control, it was concluded that the level of improvement with ANNC did not warrant the extra effort in tuning and implementation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-09-08 15:02:28.177
9

Development of a vibration absorbing handle for rock drills

Strydom, Johannes Petrus De Wet 12 January 2007 (has links)
Excessive vibration exerted on the human body can cause many harmful phenomena that can result in permanent bodily damage or permanent disability. Human vibration is classified into two main categories: Hand,arm vibration and whole,body vibration. Hand,arm vibration is vibration transmitted through a percussive tool handle via the hand,arm system to the rest of the body. The main diseases concerning hand,arm vibration are Vibration White Finger (VWF), neurological diseases in the hand and fingers and musculoskeletal diseases like carpal tunnel syndrome. These diseases, especially VWF and musculoskeletal disorders, are mainly associated with lower frequencies. VWF in particular is more likely to occur when an operator is subjected to vibrations with high magnitudes in the 25-40 Hz region. The operating frequencies of most rock drills vary between 30 and 50 Hz. Although there are many other contributing factors like grip force, hand temperature and subject variability, prevalence of VWF among rock drill operators is relatively high in the world. The situation in South Africa is not yet very clear, and further research must be done to evaluate the current status of VWF in South Africa. Vibration energy at higher frequencies can be attenuated with rubber grips or gloves, and these types of dampers are already available on the market. The problem concerning the operating frequency of the drill has not yet been successfully addressed, and thus remains a problem in the rock drill industry as it is at the moment. The main objective of this thesis was the development and testing of a concept that can potentially be implemented on a rock drill to attenuate the operating frequency of a rock drill. The concept must be able to account for minor changes in operating frequency on a specific drill. In addition to that, the drill operating frequency varies from one drill to another. The thesis also aims to lay the mathematical foundation to design an attenuating handle for a specific drill with a specific operating frequency. All the objectives must be obtained without noticeable sacrifices in drill control or performance. The thesis includes the concept generation, optimisation, design and manufacture of a rock drill vibration absorber. The absorber has been tested, and the results are presented. / Dissertation (M Eng (Mechanical Engineering))--University of Pretoria, 2007. / Mechanical and Aeronautical Engineering / unrestricted
10

Trends in Vacuum Technology and Pneumatics in the Context of Digitalization

Schmalz, Kurt, Winter, Albrecht 03 May 2016 (has links) (PDF)
Digitalization is finding it’s way into production and machine-building. Autonomous, sefoptimizing and highly interconnected units will determine the functionality of machines and production facilities. Communication and automation layout will fundamentally change, data will be more and more the base for new business modells. Innovation is determining pneumatics and handling technology. The innovation topics performance improvement, modular and mechatronic design of systems, sustainability and efficiency are keeping pneumatics and vacuum technology on the pathway of success. But is the technology field also prepared for the tremendous challenges caused by the digitalization? This paper is focusing on the significance of digitalization for fluid technology, especially for pneumatics and vacuum technology. The new concepts of digitalization and autonomization are based on the Internet of Things with open Communication of cyber-physical systems. These cyber-physical systems are able to react autonoumously. Cyber-physical systems can collect, interpret and analys data and transfer it into valuable information. Based on these data, cyberphysical systems will provide services to all participants of the smart factory. There will be a digital image inside the factory cloud, which is the base of new business models. Systems of pneumatics, vacuum technology and hydraulics will play a core role in this world. They are placed directly at the interface to the real technical process, they have direct contact with the workpieces, they are collecting multitude of sensor data and are evaulating it, they have functionality like Condition Monitoring and Energy Efficiency optimization on board and are able to communicate with the world of automation. This paper will show, that the innovation trends of the last years are supporting the way towards digitalization and Industrial Internet of Things. There are already a lot of different approaches to establish vacuum and pneumatic systems as adequate elements of the digitalized world. It will also be shown, that fluid technology still is facing tremendous challenges It will be not sufficient to equip the systems with more functionality and better communication. It will be essential, that from the interpretation and correlation of data will be derived valuable services with real customer benefit. This should happen under control of the vendors of smart field devices in fluid technology. Then it will be possible to turn this new kind of value generation also into new business models.

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