Training course for radiation safety technicians

Course of instruction includes sections on basic information, natural radioactivity, properties of alpha, beta, gamma, X rays, and neutrons, concepts of radiation units and dose determinations, shielding, biological effects, background radiation, radiation protection standards, and internal dose calculation

Extension of modern control system theory Final report

Analysis and synthesis techniques for linear systems and methods of minimizing sensitivity of optimal control systems to large parameter variation

Selection of Motor Oil

SummaryKnowledge of different types and classifications of crankcase oils means savings when selecting motor lubricants. In many cases farmers take recommendations of dealers and salesmen when buying oils, because of confusion on types and grades, different engines and conditions under which engines operate.Crankcase oils perform four main functions in internal combustion engines. They are:I. Lubricating- this is accomplished by forming a protective film between bearing surfaces to prevent metal to metal contact. Friction and abrasive wear is reduced.2. Sealing - oil forms a seal between piston, rings and cylinder wall to prevent loss of power and crankcase contamination.3. Cooling - oil helps to carry away a large amount of heat produced in the engine.4. Cleaning - oil aids in keeping engines clean by holding impurities or sediments in suspension and reducing deposit formation.Some other functions include: reducing noise, cushioning shock, and protection of parts. How well these functions are performed depends on type and quality of oil used in the engine

The South Dakota Pasture Furrower

After several years of research and field testing, agricultural engineers have introduced a new model tractor-drawn pasture furrower specifically designed to overcome these objections. It can be made in a well-equipped farm shop from commercially available parts. Detailed plans and design information for construction of the pasture furrower are included in the back (pages 11 -15) of this publication. Method of operation and results of testing are included in the discussion which follows

Comparison of Heating Efficiency of a Heat Pump to Electric Heating Panels

Several questions may be raised about the practicability of the heating feature of a heat pump. Is the heat pump as economical to operate as the ordinary air conditioner and a separate heating system? What months during the year could the heat pump be operated to the best advantage? Could the heat pump supply all the heat requirements for South Dakota conditions? Because there were so many unknown factors involved it was impossible to estimate the operating cost by calculation. Therefore, the purpose of this study was to compare the operating efficiency of a commercially available heat pump air conditioner ( window model) with that of an electric heating panel under actual operating conditions in a single room

The binary fraction of planetary nebula central stars I. A high-precision, I-band excess search

In an attempt to determine how many planetary nebulae derive from binary interactions, we have started a project to measure their unbiased binary fraction. This number, when compared to the binary fraction of the presumed parent population can give a first handle on the origin of planetary nebulae. By detecting 27 bona fide central stars in the I band we have found that 30% of our sample have an I band excess between one and a few sigmas, possibly denoting companions brighter than M3-4V and with separations smaller than approximately 1000 AU. By accounting for the undetectable companions, we determine a de-biased binary fraction of 67-78% for all companions at all separations. We compare this number to a main sequence binary fraction of (50+/-4)% determined for spectral types F6V-G2V, appropriate if the progenitors of today's PN central star population is indeed the F6V-G2V stars. The error on our estimate could be between 10 and 30%. We conclude that the central star binary fraction may be larger than expected from the putative parent population. Using the more sensitive J band of a subset of 11 central stars, the binary fraction is 54% for companions brighter than approximately M5-6V and with separations smaller than about 900 AU. De-biassing this number we obtain a binary fraction of 100-107%. The two numbers should be the same and the discrepancy is likely due to small number statistics. We also present an accurately vetted compilation of observed main sequence star magnitudes, colours and masses, which can serve as a reference for future studies. We also present synthetic colours of hot stars as a function of temperature (20-170kK) and gravity (log g= 6-8) for Solar and PG1159 compositions.Comment: 22 pages, 6 figures, 12 tables, accepted by MNRA

EUV Sunspot Plumes Observed with SOHO

Bright EUV sunspot plumes have been observed in five out of nine sunspot regions with the Coronal Diagnostic Spectrometer -- CDS on SOHO. In the other four regions the brightest line emissions may appear inside the sunspot but are mainly concentrated in small regions outside the sunspot areas. These results are in contrast to those obtained during the Solar Maximum Mission, but are compatible with the Skylab mission results. The present observations show that sunspot plumes are formed in the upper part of the transition region, occur both in magnetic unipolar-- and bipolar regions, and may extend from the umbra into the penumbra.Comment: 8 pages, 3 figures, to be published in ApJ Letter