492 research outputs found
Conceptual and Preliminary Design of a Stowable Ruggedized Micro Air Vehicle
This study presents both feasibility and preliminary design studies of a ruggedized, stowable, ballistically launched Micro Air Vehicle (MAV). A vehicle capable of being stored within a 40 mm diameter, 133 mm long cylinder and able to withstand a significantly rough environment when stowed was desired. Minimum performance specifications were a 20% range increase from a 450 m range, 45° launch angle ballistic trajectory and a gliding time of 30 s from the apex of said trajectory. To this end, a study of comparable MAV systems, available control and communication electronics, low Reynolds number flight, ballistic flight, and advanced projectiles was conducted. It was found that the concept was possible using current electronics, however, these would require a large majority of the available volume necessitating the novel, compact, wing stowage systems discussed within. While aerodynamically feasible the transition between ballistic and aircraft flight will necessitate significant sensor and control logic design. The small scales of this project necessitated consideration of the vagaries of low Reynolds number flight. Despite the final design proposals maintaining chordwise Reynolds numbers greater than 100,000 several key trends were found to be significantly different than those encountered in classical aerodynamic theory; particularly the existence of an optimum aspect ratio for maximum lift to drag ratio of the wing alone. For a fixed wing area and velocity increasing the aspect ratio, thereby reducing induced drag, also reduced the chordwise Reynolds number which reduced the efficiency of the airfoil. At the optimum benefits from reducing induced drag balanced with the penalties of reduced airfoil performance. The feasibility study focused primarily on volumetric concerns; minimizing stowed wing volume was the main goal. Several design iterations were constructed in SolidWorks prior to the development of two concepts ready for prototyping and testing. Design optimization was performed with both classical semi-empirical methods using Missile DATCOM and a custom in-house Matlab code as well as the Fluent CFD package. Significant work was done to find a suite of solver settings and mesh generation parameters capable of predicting 2D and 3D low Reynolds number airfoil performance with sufficient quality for preliminary design work. Optimization studies found that achieving both initial performance goals with a single aircraft would be highly inefficient. This effort concluded with a pair of designs, one high-speed cruise-to-target version capable of 700 m range and 9 s gliding time optimized for rapid-response, and a long-endurance glider with a flight time greater than 60 s optimized for surveillance purposes
Enhanced photothermal displacement spectroscopy for thin-film characterization using a Fabry-Perot resonator
We have developed a technique for photothermal displacement spectroscopy that is potentially orders of magnitude more sensitive than conventional methods. We use a single Fabry-Perot resonator to enhance both the intensity of the pump beam and the sensitivity of the probe beam. The result is an enhancement of the response of the instrument by a factor proportional to the square of the finesse of the cavity over conventional interferometric measurements. In this paper we present a description of the technique, and we discuss how the properties of thin films can be deduced from the photothermal response. As an example of the technique, we report a measurement of the thermal properties of a multilayer dielectric mirror similar to those used in interferometric gravitational wave detectors
Cross-reporting of Interpersonal Violence and Animal Cruelty: The Charlotte Project
The overlapping nature of interpersonal violence and animal cruelty is well established, however historically each issue has been addressed by distinct and separate protective systems. An innovative community-based project is described that utilized crosstraining as a mechanism to foster collaboration between human services and animal control agencies. Findings are useful for professionals and community stakeholders interested in facilitating the cross-reporting of interpersonal violence and animal cruelty
Pemanfaatan Air Cucian Surimi Belut Sawah (Monopterus Albus) Dalam Pembuatan Edible Film
The purpose of this research was to obtain edible film that meet physical and chemical characterictics of Japan Internasional Standard (JIS). This research was conducted from June 2015 to December 2015. This research used the randomized bloc design with one factor, the addition of eel surimi waste water (0 mL, 12 mL, 15 mL dan 18 mL). The observed parameters included chemical (water activity) and physical (thickness, percent of elongation, vapor transmission rate) characterictics. The results showed that there were no significant effects on thickness water activity, vapor transmission rate and percent of elongation. Furthermore, the edible film met Japan Industrial standard (JIS) based on thickness 0.139 to 0.214 mm, vapor transmission rate 3.514 to 7.133 g/m2/jam and the percent of elongation 106.22% to 174.55%
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