Liquid drop technique for generation of organic glass and metal shells

It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed

Method of detecting oxygen in a gas

The presence of oxygen in a gas is detected by contacting an article, such as a film, comprising poly(ethylenenaphthalene-dicarboxylate) with a gas and simultaneously exposing the article to ultraviolet light. The article is subsequently heated and the presence of oxygen in the gas is indicated by thermoluminescence

Fiber optics wavelength division multiplexing(components)

The long term objectives are to develop optical multiplexers/demultiplexers, different wavelength and modulation stable semiconductor lasers and high data rate transceivers, as well as to test and evaluate fiber optic networks applicable to the Space Station. Progress in each of the above areas is briefly discussed

Brief state-of-the-art review on optical communications for the NASA ISES workshop

The current state of the art of optical communications is briefly reviewed. This review covers NASA programs, DOD and other government agency programs, commercial aerospace programs, and foreign programs. Included is a brief summary of a recent NASA workshop on optical communications. The basic conclusions from all the program reviews is that optical communications is a technology ready to be accepted but needed to be demonstrated. Probably the most advanced and sophisticated optical communications system is the Laser Intersatellite Transmission Experiment (LITE) system developed for flight on the Advanced Communications Technology Satellite (ACTS). Optical communications technology is available for the applications of data communications at data rates in the under 300 MBits/sec for nearly all applications under 2 times GEO distances. Applications for low-earth orbiter (LEO) to ground will allow data rates in the multi-GBits/sec range. Higher data rates are limited by currently available laser power. Phased array lasers offer technology which should eliminate this problem. The major problem of cloud coverage can probably be eliminated by look ahead pointing, multiple ground stations, and knowledge of weather conditions to control the pointing. Most certainly, optical communications offer a new spectral region to relieve the RF bands and very high data communications rates that will be required in less than 10 years to solve the communications problems on Earth

Resolution changes in lithium-drifted silicon semiconductor detectors irradiated with 0.5, 1.0, 2.0, and 3.0 MeV electrons

Electron irradiation effect on resolution of lithium-drifted silicon semiconductor detector

A numerical solution of the Navier-Stokes equations for chemically nonequilibrium, merged stagnation shock layers on spheres and two-dimensional cylinders in air

Results of solving the Navier-Stokes equations for chemically nonequilibrium, merged stagnation shock layers on spheres and two-dimensional cylinders are presented. The effects of wall catalysis and slip are also examined. The thin shock layer assumption is not made, and the thick viscous shock is allowed to develop within the computational domain. The results show good comparison with existing data. Due to the more pronounced merging of shock layer and boundary layer for the sphere, the heating rates for spheres become higher than those for cylinders as the altitude is increased

Competitive comparison in music: influences upon self-efficacy beliefs by gender

This study profiles gender differences in instrumental performance self-efficacy perceptions of high school students (N = 87) over the course of a three-day orchestra festival in which students competed against one another for rank-based seating and then rehearsed and performed as a group. Reported self-beliefs rose significantly for the sample over the course of the festival. Self-efficacy beliefs of females were significantly lower than those of males before the seating audition and first rehearsal, but were no longer different by the midpoint of the festival. Survey free-response data were coded according to Bandura's (1997 Bandura, A. 1997. Self-efficacy: The Exercise of Control. New York: W. H. Freeman.) four sources of self-efficacy. A 52% drop in the frequency of student comments regarding competitive comparison appeared at the same point in which female self-efficacy beliefs were no longer different from those of males. Results support past research to suggest that males and females may respond differently to rank-based competition versus social support

NASA/Launch Services SMA Involvement

No abstract availabl

Structuring a Wayfinder\u27s Dynamic and Uncertain Environment

Wayfinders typically travel in dynamic environments where barriers and requirements change over time. In many cases, uncertainty exists about the future state of this changing environment. Current geographic information systems lack tools to assist wayfinders in understanding the travel possibilities and path selection options in these dynamic and uncertain settings. The goal of this research is a better understanding of the impact of dynamic and uncertain environments on wayfinding travel possibilities. An integrated spatio-temporal framework, populated with barriers and requirements, models wayfinding scenarios by generating four travel possibility partitions based on the wayfinder\u27s maximum travel speed. Using these partitions, wayfinders select paths to meet scenario requirements. When uncertainty exists, wayfinders often cannot discern the future state of barriers and requirements. The model to address indiscemibility employs a threevalued logic to indicate accessible space, inaccessible space, and possibly inaccessible space. Uncertain scenarios generate up to fifteen distinct travel possibility categories. These fifteen categories generalize into three-valued travel possible partitions based on where travel can occur and where travel is successful. Path selection in these often-complex environments is explored through a specific uncertain scenario that includes a well-defined initial requirement and the possibility of an additional requirement somewhere beforehand. Observations from initial path selection tests with this scenario provide the motivation for the hypothesis that paths arriving as soon as possible to well-defined requirements also maximize the probability of success in meeting possible additional requirements. The hypothesis evaluation occurs within a prototype Travel Possibility Calculator application that employs a set of metrics to test path accessibility in various linear and planar scenarios. The results did not support the hypothesis, but showed instead that path accessibility to possible additional requirements is greatly influenced by the spatio-temporal characteristics of the scenario\u27s barriers

Roborodentia

This project is an autonomous robot, designed to perform a series of basic tasks without any human input. It’s based on the 2018 Roborodentia competition, in which teams of students design and build a small (roughly 1 square foot) robot that collects small foam spheres from vertical tubes on the edges of a table-sized arena, and shoot them into goals across the field. The more foam spheres the robot makes into the goals after a 3 minute time period, the more points they get. The challenge is doing so autonomously, without any human input after the initial timer for the start of the match. Several assistive elements are laid out on the field to allow a robot to detect its surroundings without human input. One such element, found on the floor of the field, is lines of black electrical tape against the white background that lead to all four vertical loading stations, as well as a separate horizontal loading station. The robot I built detects these lines using a series of infrared sensors, and navigates from loading station to loading station using these lines as guides, shooting the foam spheres into goals along the way