Apparatus for Dielectric Constant Measurements and Measurements for Water-Methanol Mixtures

A system for measuring dielectric constants has been constructed using a Sargent Oscillometer and an air bath for temperature control. The design and construction of the air bath as well as the temperature control achieved with it are described. The overall performance of the system including a computer program for forming the calculations is described. The system is one that requires calibration using two or more standard solvents and is good for both conducting and non-conducting liquids. Data are presented for water-methanol mixtures at 25 degrees with several points near pure methanol and also near pure wate

Rapid Electroosmosis Measurements

A cell has been designed and built that allows for rapid measurement of volume moved in a definite time by electroosmosis. The cell is simple to use and is not very elaborate. Using a water jacket, the cell temperature can be controlled to ± 0.1° C. Measurements are presented for acetonitrile, dimethylformamide, and nitrobenzene at 25° C for applied voltages of 25, 50, 75, and 100 volts

The development of spectro-signature indicators of root disease on large forest areas Annual progress report

Visible and near infrared spectrometric tests of selected black and white film-filter combinations for descriminating between healthy and diseased Douglas fir tree

Chemistry Departments in Predominantly Black Institutions

Chemistry programs in 87 predominantly Black institutions were compared by questionnaire survey. Advanced undergraduate courses were offered for chemistry majors by 86% of these schools, but only 28% offered research and independent study for undergraduates. Although there were extremes, most of the faculty taught 15 to 18 contact hours and their median salaries were below the national median. Library support seemed adequate with 1 to 1.5% of the total library materials being chemistry books, texts and reference, and the libraries of most schools had holdings of 15 principal chemistry-related journals. More than 90% of the schools were well-equipped with laboratory instrumentation for the undergraduate program. One-third of the schools were recipients of current grants, but less than 50% of these grants were for research. At the time of the survey there was a median of 13 chemistry majors in the schools, but this has been increasing since. On the basis of 45% response from individual faculty members of these schools, all faculty members had post-baccalaureate degrees, with 2/3 holding the doctoral degree. Only about 2/3 of the respondents indicated professional activity via scientific meeting attendance and/or recent publication. Most respondents (92%) were members of the American Chemical Society, but membership in other professional societies was much less common. Responses by these faculty members indicated that up-to-date instructional methods were generally being used

Rocket engine Patent

Metal ion rocket engine desig

Low-pressure performance of annular, high-pressure (40 atm) high-temperature (2480 K) combustion system

Experimental tests were conducted to develop a combustion system for a 40 atmosphere pressure, 2480 K exhaust gas temperature, turbine cooling facility. The tests were conducted in an existing facility with a maximum pressure capability of 10 atmospheres and where inlet air temperatures as high as 894 K could be attained. Exhaust gas temperatures were as high as 2365 K. Combustion efficiences were about 100 percent over a fuel air ratio range of 0.016 to 0.056. Combustion efficiency decreased at leaner and richer ratios when the inlet air temperature was 589 K. Data are presented that show the effect of fuel air ratio and inlet air temperature on liner metal temperature. Isothermal system pressure loss as a function of diffuser inlet Mach number is also presented. Data included exhaust gas pattern factors; unburned hydrocarbon, carbon monoxide, and oxides of nitrogen emission index values; and smoke numbers

Pollution emissions from single swirl-can combustor modules at parametric test conditions

Exhaust pollutant emissions were measured from single swirl-can combustor modules operating over a pressure range of 69 to 276 N/sq cm (100 to 400 psia), over a fuel-air ratio range of 0.01 to 0.04, at an inlet air temperature of 733 K (860 F), and at a constant reference velocity of 23.2 m/sec). Many swirl-can module designs were evaluated; the 11 most promising designs exhibited oxides of nitrogen emission levels lower than that from conventional gas-turbine combustors. Although these single module test results are not necessarily indicative of the performance characteristics of a large array of modules, the results are very promixing and offer a number of module designs that should be tested in a full combustor

Accommodation requirements for microgravity science and applications research on space station

Scientific research conducted in the microgravity environment of space represents a unique opportunity to explore and exploit the benefits of materials processing in the virtual abscence of gravity induced forces. NASA has initiated the preliminary design of a permanently manned space station that will support technological advances in process science and stimulate the development of new and improved materials having applications across the commercial spectrum. A study is performed to define from the researchers' perspective, the requirements for laboratory equipment to accommodate microgravity experiments on the space station. The accommodation requirements focus on the microgravity science disciplines including combustion science, electronic materials, metals and alloys, fluids and transport phenomena, glasses and ceramics, and polymer science. User requirements have been identified in eleven research classes, each of which contain an envelope of functional requirements for related experiments having similar characteristics, objectives, and equipment needs. Based on these functional requirements seventeen items of experiment apparatus and twenty items of core supporting equipment have been defined which represent currently identified equipment requirements for a pressurized laboratory module at the initial operating capability of the NASA space station

Primer selection impacts specific population abundances but not community dynamics in a monthly time-series 16S rRNA gene amplicon analysis of coastal marine bacterioplankton.

Primers targeting the 16S small subunit ribosomal RNA marker gene, used to characterize bacterial and archaeal communities, have recently been re-evaluated for marine planktonic habitats. To investigate whether primer selection affects the ecological interpretation of bacterioplankton populations and community dynamics, amplicon sequencing with four primer sets targeting several hypervariable regions of the 16S rRNA gene was conducted on both mock communities constructed from cloned 16S rRNA genes and a time-series of DNA samples from the temperate coastal Santa Barbara Channel. Ecological interpretations of community structure (delineation of depth and seasonality, correlations with environmental factors) were similar across primer sets, while population dynamics varied. We observed substantial differences in relative abundances of taxa known to be poorly resolved by some primer sets, such as Thaumarchaeota and SAR11, and unexpected taxa including Roseobacter clades. Though the magnitude of relative abundances of common OTUs differed between primer sets, the relative abundances of the OTUs were nonetheless strongly correlated. We do not endorse one primer set but rather enumerate strengths and weaknesses to facilitate selection appropriate to a system or experimental goal. While 16S rRNA gene primer bias suggests caution in assessing quantitative population dynamics, community dynamics appear robust across studies using different primers

Ceramic coating effect on liner metal temperatures of film-cooled annular combustor

An experimental and analytical investigation was conducted to determine the effect of a ceramic coating on the average metal temperatures of full annular, film cooled combustion chamber liner. The investigation was conducted at pressures from 0.50 to 0.062. At all test conditions, experimental results indicate that application of a ceramic coating will result in significantly lower wall temperatures. In a simplified heat transfer analysis, agreement between experimental and calculated liner temperatures was achieved. Simulated spalling of a small portion of the ceramic coating resulted in only small increases in liner temperature because of the thermal conduction of heat from the hotter, uncoated liner metal