A rocket-borne electric field meter for the middle atmosphere

The design and construction of a rocket-borne electric field meter for determining the atmosphere's electric field and the conductivity in the middle atmosphere are considered. The operating characteristics of the instrument are discussed and a proposed flight configuration is given. The testing of the prototype is described and suggestions are advanced for further improvements

A Novel Design of Vitual and Mixed Reality Scenarios for Automation Training

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Andrés Salinas-Hernández on April 23, 2021

New metrology for radon at the environmental level

International audienc

Atmospheric electric charge transfer in precipitation and associated synoptic conditions

Measurements of Atmospheric Electricity have been made in the unpolluted air of Weardale during conditions of precipitation and in fair weather. An automatic recording system has been built to digitize instrument outputs on paper-tape for subsequent computer analysis. The system ivas installed and run at Lanehead Field Centre and was also used to process magnetic tape recordings from the LandRover mobile station. The system was expanded to include an 1-hour smoothing and sampling action for recording aveiaged values of fair weather Atmospheric Electricity. At times of electrically quiet precipitation, measurements have been made of potential gradient, precipitation current density, space charge density and both polar conductivities. A new method of compensation for displacement currents has been used. Conductivity measurements have revealed a charge separation process close to the ground in rain, but not in snow. Techniques of variance spectrum analysis have been adopted for the precipitation work. Coherency spectra of potential gradient with precipitation current have indicated electrical 'cells' in nimbostratus and their relevance to weather forecasting is discussed. The phase spectra for these two parameters have been examined to measure the height of electrical activity and this is found to coincide with the melting level, and an estimate is made of the conductivity of the charging region of the cloud. Digital filtering of records has disclosed a mechanical-transfer current of space charges, to an exposed rain receiver, opposite to the precipitation current. The diurnal variation of potential gradient at Lanehead has been refined with a further year's continuous observations in fair weather and seasonal differences in the diurnal variations of potential gradient, air- earth -current density and space charge density have been explained by increased convection in summer. The conduction current has been estimated, by the indirect method and the difference between this and the total air-earth current to an exposed plate is attributed to a mechanical-transfer current of space charges. Measurements in light winds have evinced the influence of the electrode effect

Vibration Analysis of Modern Fire Apparatus

A purpose-built, novel sensor was developed to facilitate vibration recording of modern fire apparatus. A front-end recording virtual instrument was developed using the National Instruments LabView suite. A second virtual instrument was designed to normalize the data to standard gravity and to characterize its spectral content. Preliminary baseline tests showed that the low-cost sensor provided adequate signal to noise ratios. Vibration characterization of pumper apparatus revealed pump induced vibrations were in excess of 0.26 g. Documentation and instructions on the operation of the sensor are contained herein for usage in subsequent vibration recording of fire apparatus

Augmented reality for computer assisted orthopaedic surgery

In recent years, computer-assistance and robotics have established their presence in operating theatres and found success in orthopaedic procedures. Benefits of computer assisted orthopaedic surgery (CAOS) have been thoroughly explored in research, finding improvements in clinical outcomes, through increased control and precision over surgical actions. However, human-computer interaction in CAOS remains an evolving field, through emerging display technologies including augmented reality (AR) – a fused view of the real environment with virtual, computer-generated holograms. Interactions between clinicians and patient-specific data generated during CAOS are limited to basic 2D interactions on touchscreen monitors, potentially creating clutter and cognitive challenges in surgery. Work described in this thesis sought to explore the benefits of AR in CAOS through: an integration between commercially available AR and CAOS systems, creating a novel AR-centric surgical workflow to support various tasks of computer-assisted knee arthroplasty, and three pre–clinical studies exploring the impact of the new AR workflow on both existing and newly proposed quantitative and qualitative performance metrics. Early research focused on cloning the (2D) user-interface of an existing CAOS system onto a virtual AR screen and investigating any resulting impacts on usability and performance. An infrared-based registration system is also presented, describing a protocol for calibrating commercial AR headsets with optical trackers, calculating a spatial transformation between surgical and holographic coordinate frames. The main contribution of this thesis is a novel AR workflow designed to support computer-assisted patellofemoral arthroplasty. The reported workflow provided 3D in-situ holographic guidance for CAOS tasks including patient registration, pre-operative planning, and assisted-cutting. Pre-clinical experimental validation on a commercial system (NAVIO®, Smith & Nephew) for these contributions demonstrates encouraging early-stage results showing successful deployment of AR to CAOS systems, and promising indications that AR can enhance the clinician’s interactions in the future. The thesis concludes with a summary of achievements, corresponding limitations and future research opportunities.Open Acces

SYSTEM INTEGRATION OF C-ARM ROBOTIC PROTOTYPE USING MOTION CAPTURE GUIDANCE FOR ACCURATE REPOSITIONING

One of the important surgical tools in spinal surgery is the C-Arm X-ray System. The C-Arm is a large “C” shaped and manually maneuvered arm that provides surgeons and X-ray technicians the ability to take quick quality X-rays during surgery. Because of its five degrees of freedom, the C-Arm can be manually maneuvered around the patient to provide many angles and perspectives, ensuring surgical success. This system works fine for most surgical procedures but falls short when the C-Arm must be moved out of the way for complicated surgical procedures. The aim of this thesis is to develop an accurate repositioning method with the use of motion capture technology. This will be a novel approach to creating a repositioning integrated system. To develop a motion capture repositioning integrated system, a set of research tasks needed to be completed. A virtual prototype and a virtual platform were developed that quantified the dynamics of the C-Arm maneuvering. Next, a complete kinematic model of the C-Arm was developed. Third, a fully automatic robotic C-Arm prototype was designed and manufactured to serve as a replacement for the actual C-Arm. Finally, the robotic prototype, the virtual platform, and the kinematic model were all systematically integrated using Vicon motion capture system to perform the automatic repositioning of the C-Arm. Testing of the newly developed repositioning system was completed with successful results

Metal Forming Force Measurement

ME450 Capstone Design and Manufacturing Experience: Fall 2015Clips and Clamps Industries (CCI) produces small metal parts, many of which are formed using metal forming fourslide machines. CCI’s fourslide machines have been experiencing failures and increased maintenance due to the usage of high-strength steels that require more force to form. In order to minimize damage and maintenance, CCI has asked to implement a sensor that detects the forces on the slide while the machine is in operation, to incorporate a safety control to automatically shut off the machine when a programmed force is exceeded, and to calculate the maximum tonnage rating on the forming section—specifically the front slide as this is the area prone to failure. This design must also be scalable so that it may be implemented on both the smaller, S3F and larger, S4F machines. After initial research and defining the project scope, finite element analysis simulations on the slide and gathering feedback from sponsors at CCI and professors at the University of Michigan, the final design was solidified as a Wintriss strain link sensor bolted to the top of the slide. Through Solidworks CAD models, data was gathered regarding strains on the slide to justify the location of the sensor while assuring that the design would not hinder the fourslide machine operation or compromise safety. The risk associated with the design has been assessed in both a risk analysis and FMEA, raising concerns with safety and potential failures. The final design has been manufactured and was installed in a fourslide machine at CCI. To validate whether the design meets the project requirements, the strain link was calibrated with a load cell to ensure accuracy as well as tested to ensure functionality of auto-shutoff capability. Additionally, through theoretical modeling including finite element and fatigue analysis, the maximum tonnage rating was determined to be 4.5 tons. This maximum tonnage rating will be validated and further refined through empirical testing over time carried out by CCI.http://deepblue.lib.umich.edu/bitstream/2027.42/117336/1/ME450-F15-Project17-FinalReport.pd

3D Spectrophotometry of Planetary Nebulae in the Bulge of M31

We introduce crowded field integral field (3D) spectrophotometry as a useful technique for the study of resolved stellar populations in nearby galaxies. As a methodological test, we present a pilot study with selected extragalactic planetary nebulae (XPN) in the bulge of M31, demonstrating how 3D spectroscopy is able to improve the limited accuracy of background subtraction which one would normally obtain with classical slit spectroscopy. It is shown that due to the absence of slit effects, 3D is a most suitable technique for spectrophometry. We present spectra and line intensities for 5 XPN in M31, obtained with the MPFS instrument at the Russian 6m BTA, INTEGRAL at the WHT, and with PMAS at the Calar Alto 3.5m Telescope. Using 3D spectra of bright standard stars, we demonstrate that the PSF is sampled with high accuracy, providing a centroiding precision at the milli-arcsec level. Crowded field 3D spectrophotometry and the use of PSF fitting techniques is suggested as the method of choice for a number of similar observational problems, including luminous stars in nearby galaxies, supernovae, QSO host galaxies, gravitationally lensed QSOs, and others.Comment: (1) Astrophysikalisches Institut Potsdam, (2) University of Durham. 18 pages, 11 figures, accepted for publication in Ap