High Efficiency Multistage Plasma Thrusters (HEMPTs) are a relatively new form of electric propulsion that show promise for use on a variety of missions and have several advantages over their older EP competitors. One such advantage is their long predicted lifetime and minimal wall erosion due to a unique periodic permanent magnet system. A laboratory HEMPT was built and donated by JPL for testing at Cal Poly. Previous work was done to characterize the performance of this thruster and it was found to exhibit a large plume divergence, resulting in decreased thrust and specific impulse. This thesis explores the design and application of a magnetic shield to modify the thruster’s magnetic field to force more ion current towards the centerline. A previous Cal Poly thesis explored the same concept, and that work is continued and furthered here. The previous thesis tested a shield which increased centerline current but decreased performance. A new shield design which should avoid this performance decrease is studied here. Magnetic modelling of the thruster was performed using COMSOL. This model was verified using guassmeters to measure the field strength at many discrete points within and near the HEMPT, with a focus on the ionization channel and exit plane. A shield design which should significantly reduce the radial field strength at the exit plane without affecting the ionization channel field was modelled and implemented. The HEMPT was tested in a vacuum chamber with and without the shield to characterize any change to performance characteristics. Data were collected using a nude Faraday probe and retarding potential analyzer. The data show a significant increase in centerline current with the application of the shield, but due to RPA malfunction and thruster failure the actual change in performance could not be concluded. The unshielded HEMPT was characterized, however, and was found to produce 12.1 +/- 1.3 mN of thrust with a specific impulse of 1361 +/- 147s. The thruster operated with a total efficiency of 10.63 +/- 3.66%, an efficiency much lower than expected. A large contributor to this low efficiency is likely the use of argon in place of xenon. Its lower mass and higher ionization energy make it a less efficient propellant choice. Further, the thruster is prone to overheating, indicating that significant thermal losses are present in this design.

This diploma thesis describes implementation of an indoor positioning system for tracking the location and movement of material and products through the manufacturing plant. The system is designed with regards to simple installation and low overall implementation costs. It utilizes method of Wi-Fi and magnetic field fingerprinting. The system employs a client hardware (active tag with Wi-Fi module and sensors designed for this project) communicating with a server software which does the mapping and fingerprinting processing. Finall positioning system is prepared to collect locations data for further analysis aiming to improve efficiency of manufacturing processes.

Presented work consists of research and experimental part. Main focus of the research part is on mutual interaction between magnetic field and water and between magnetic field and cavitating flow. Prediction of the result is almost impossible, because the opinions on the effects differ, sometimes even go against each other. Experimental part consisted of three trials with permanent magnets. Electromagnetic probe was employed for measuring of the voltage. It appears, that magnetic field affects the cavitation, because in all of the trials the measured voltage changed after the switch from non-cavitating to cavitating flow. The change of the voltage was not great enough, thus application of this phenomenon in practice cannot be recommended.

Diploma thesis describes types and measuring principes of magnetic field as first. Furthermore it deals with parameters of sensor HMC2003 and data acquision. Selected card for acquision was USB-6218 from company National Instruments. After that project describes programing interface LabVIEW, which was used for desing of acquision program. Next part deals with comuncation between card and computer, drivers and properties of card. After that were explained requirements on measuring interface. Furthermore it deals with basic parts of the acquision software and describes its function with connection to user interface. Finally the interface was tested.

The aim of this work deals with the design and manufacture of a device for mixing of magnetic beads in solution by magnetic field. It is based on my previous bachelor thesis, where the device was created for one microtube (one sample). In this following work, the three improved variants for mixing and separation of 96 samples at one time were designed. The first variant of device, derived from functional prototype from bachelor thesis, was manufactured. First, the magnetic circuit and power converter were designed. Subsequently, the device was manufactured just for one microtube due to functionality testing. The third variant was realized only experimentally, the construction was designed in CAD program, and individual parts were created using 3D printer. As an alternative solution, which should be the compromise among electromagnetic and mechanical stirring, additional prototype was manufactured using 3D printer and CNC instrument. This prototype utilizes neodymium magnets and a stepper motor. The capability of magnetic beads mixing in solution was verified.

Cancer prevails as one of the most devastating diseases being at the top of death causes for adults despite continuous development and innovation in cancer therapy. Nanotechnology may be used to achieve therapeutic dosing, establish sustained-release drug profiles, and increase the half-life of drugs. In this context, magnetic nanowires (NWs) have shown a good biocompatibility and cellular internalization with a low cytotoxic effect. In this thesis, I induced cancer cell death by combining the chemotherapeutic effect of iron NWs functionalized with Doxorubicin (DOX) with mechanical disturbance under a low frequency alternating magnetic field. Two different agents, APTES and BSA, were separately used for coating NWs permitting further functionalization with DOX. Internalization was qualitatively and quantitatively assessed for both formulations by confocal reflection microscopy and inductively coupled plasma-mass spectrometry. From confocal reflection analysis, BSA formulations demonstrate to have a higher internalization degree and a broader distribution within the cells in comparison to APTES formulations. Both groups of functionalized NWs generated a comparable cytotoxic effect in MDA-MB-231 breast cancer cells in a DOX concentration-dependent manner, (~60% at the highest concentration tested) that was significantly different from the effect produced by the free DOX (~95% at the same concentration) and non-functionalized NWs formulations (~10% at the same NWs concentration). A synergistic cytotoxic effect is obtained when a low frequency magnetic field (1 mT, 10 Hz) is applied to cells treated with the two formulations that is again comparable (~70% at the highest concentration). Furthermore, the cytotoxic effect of both groups of coated NWs without the drug increased notoriously when the field is applied (~25% at the highest concentration tested). Here, a novel bimodal method for cancer cell destruction was developed by the conjugation of the magneto-mechanical properties of the iron NWs coupled with the chemotoxic effect of an anticancer drug. Moreover, it was demonstrated that iron nanowires possess an outstanding biocompatibility and showed high efficacy as drug delivery agents coupled to a high degree of cell internalization. Finally, the proposed method benefits from the low power fields applied during treatment. This poses much less safety risks and allows using cheaper and simpler equipment.

This work deals with simple fluxmeter which is able, together with other device, to show hysteresis loop. Hysteresis loop is a graphic expression of dependence of magnetic induction on intensity of magnetic field. Oscilloscope is used to display the hysteresis loop. This device is fully sufficient for the display. The measured objects are solenoids from various kinds of materials with the same shape. The main aim of this work is the design, realization and description of the fluxmeter. The fluxmeter consists of several partial blocks. The first one, on which this work is focused, is signal generator which is able to generace different kinds of signal. The generated signal comes on primary winding of solenoid where a magnetic field on a given intensity rises. An amplifier is used to obtain the sufficient intensity. Next thing this work is focused on is the design of the integrator which is necessary for the correct function of the fluxmeter. As suggested, there is shown the block diagram of linking of individual parts. There are described the measured results at the end of this work.

The aim of this thesis is measure the specimens placed in field of MR tomograph, the measured data to evaluace the process and measurement errors. The theoretical part is focused on describing basic parameters of magnetic field, commissioning some older methods of measurement and design methods for the measurement of samples not issuing MR signal. There is performed modeling for the proposed Metod and the 1D, 2D and 3D environments using COMSOL Multiphysics. The practical part is the measurements samples in the tomograph the Institute of Scientific Instruments Academy of Science in Brno. The measured data are processed in Marevisi and Matlab programs. The MATLAB program is written for processing, analysis and data evaluation, after which it is possible to determine the value of the magnetic susceptibility of the selected samples. In conclusion of the work is the quantification accuracy of measurements.

This thesis is concerned with problems of measuring and mapping of magnetic field in MR tomograph, for purpose of magnetic flux density homogeneity optimization. Attention is paid to mapping techniques on rotary symmetric volume and to ways of magnetic fields optimization with utilization of passive and active correction systems. Theoretical analysis of magnetic field decomposition with utilization of spherical harmonics and numerical decomposition is made. Mapping and approximation techniques of basic magnetic field are verified by experiments in the laboratory at the Institute of Scientific Instruments AS CR in Brno.

Presented diploma thesis deals with development of the autonomous electric energy source for Health and Usage Monitoring Systems placed at the rear part of a helicopter. Firstly, the HUMS systems were described briefly and the research of available energy sources was made after that. After that, the magnetic properties of the materials were described with the special focus on the permanent magnets. The draft also includes the creation of model of the magnetic field using the final element method. Prototype was assembled and the other design solutions were evaluated. The evaluation of various designs passed in the use of SOMA optimization algorithms. The generator is followed by the draft of the electronics, which streamlines and regulates a voltage supplied by the generator. At the end of the thesis, the complete source prototype was assembled and tested with two different regulators