Basic design considerations for a small scientific satellite

Scientific satellite design considerations for spacecraft itself, spacecraft/launch vehicle interface, and ground support equipment and transportatio

Infrared video tracking of UAVs: Guided landing in the absence of GPS signals

Master's Project (M.S.) University of Alaska Fairbanks, 2019Unmanned Aerial Vehicles (UAVs) use Global Positioning System (GPS) signals to determine their position for automated flight. The GPS signals require an unobstructed view of the sky in order to obtain position information. When inside without a clear view of the sky, such as in a building or mine, other methods are necessary to obtain the relative position of the UAV. For obstacle avoidance a LIDAR/SONAR system is sufficient to ensure automated flight, but for precision landing the LIDAR/SONAR system is insufficient for effectively identifying the location of the landing platform and providing flight control inputs to guide the UAV to the landing platform. This project was developed in order to solve this problem by creating a guidance system utilizing an infrared (IR) camera to track an IR LED and blue LEDs mounted on the UAV from a RaspberryPI 3 Model B+. The RaspberryPI, using OpenCV libraries, can effectively track the position of the LED lights mounted on the UAV, determine rotational and lateral corrections based on this tracking, and, using Dronekit-Python libraries, command the UAV to position itself and land on the platform of the Husky UGV (Unmanned Ground Vehicle)

Creep of plasma sprayed zirconia

Specimens of plasma-sprayed zirconia thermal barrier coatings with three different porosities and different initial particle sizes were deformed in compression at initial loads of 1000, 2000, and 3500 psi and temperatures of 1100 C, 1250 C, and 1400 C. The coatings were stabilized with lime, magnesia, and two different concentrations of yttria. Creep began as soon as the load was applied and continued at a constantly decreasing rate until the load was removed. Temperature and stabilization had a pronounced effect on creep rate. The creep rate for 20% Y2O3-80% ZrO2 was 1/3 to 1/2 that of 8% Y2O3-92% ZrO2. Both magnesia and calcia stabilized ZrO2 crept at a rate 5 to 10 times that of the 20% Y2O3 material. A near proportionality between creep rate and applied stress was observed. The rate controlling process appeared to be thermally activated, with an activation energy of approximately 100 cal/gm mole K. Creep deformation was due to cracking and particle sliding

Method of preparing zinc orthotitanate pigment

Zinc orthotitanate suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by coprecipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400 to 600 C to remove volatiles and is then rapidly heated at 900 to 1200 C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment

Pre-design study for a modern four-bladed rotor for the Rotor System Research Aircraft (RSRA)

Various candidate rotor systems were compared in an effort to select a modern four-bladed rotor for the RSRA. The YAH-64 rotor system was chosen as the candidate rotor system for further development for the RSRA. The process used to select the rotor system, studies conducted to mate the rotor with the RSRA and provide parametric variability, and the development plan which would be used to implement these studies are presented. Drawings are included

Bitten by a Bug: A Case Study in Malware Infection

This case study addresses malware infection and the organizational and technical consequences. This case study enables students to view the business continuity issues that should drive all security decisions in IT and allow analysis of the organizational and technical issues that impact recovery from a disaster that is caused by a malware infection. Information systems students seldom see case studies that involve the issues of disaster planning and business continuity within the context of what has become an ever-more frequent occurrence: a virus/worm (malware) infection. This case study would be appropriate for either undergraduate or graduate students in courses involving information resource management, MIS or information security

CHANGES OVER TIME IN THE PRACTICE OF SELF-DEFENSE AMONG YOUNG MEN IN CANADA: AN EXAMINATION OF INSECURITY AND UFC HYPOTHESES

Using multiple waves of data (1999,2004, 2009) from the General Social Survey (GSS) on victimization, the following study analyzes a number of factors thought to be influential in the practice of self-defense among young Canadian men (N=9,049) over time. Two perspectives are examined: 1) The practice of self-defense is related to feelings of insecurity among young men, and is a rational, adaptive response to perceived or actual dangerous environmental threats; 2) In addition to the effects of insecurity, the practice of self-defense should increase over time as a result of the mainstream popularity of the Ultimate Fighting Championship (UFC) and mixed martial arts, and may be the result of a potential “UFC effect”. Results indicate a strong, positive relationship between measures of insecurity (e.g., prior experience of violent victimization) and the likelihood of practicing self-defense, while evidence in support of the UFC hypothesis is, for the most part, absent. However, supplementary analyses lend partial support for the presence of such an effect, though it is less than definitive and only applies to young men of lower income. The implications of these findings are presented and discussed from both a theoretical and policy-oriented perspective

Letter from the Editor

The Richmond Journal of Law and the Public Interest is proud to present the winter issue of Volume XVI. The issue examines two areas of the law: the impact of the Religious Land Use and Institutionalized Persons Act ( RLUIPA ) and controversial issues on the outer edges of evidence law. Overall, the issue analyzes the difficulty that occurs when these laws meet practical realities