Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaves 91-95).

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaves 86-90).

An open electrolytic cell has been designed and constructed for use in a dry environment. This was used to investigate the passivation processes concerned with both the lithium and the carbon (SO2) electrodes. A.c. impedance techniques have been used in both two and three terminal cell systems in order to study the kinetics of the electrode processes. Effects of temperature, state-of-charge and reverse cell operation have been studied. Computer simulations were made of the growth of crystals on a flat (Li) surface and the resulting growth transients connecting current and time were derived. This model was extended to simulate the porous carbon (SO2) electrode and the utilisation of the carbon as a function of the depth of reaction penetration into the electrode is devised for both potentiostatic and galvanostatic discharging.

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: program; testing; modeling; blow down; discharge; dry chemical. Includes bibliographical references (p. 364-375).

Yes / Tensile properties of powder metallurgy 3% manganese-0·8% carbon (content of green compact) steels were determined following laboratory sintering in (nearly) full, semiclosed containers with no getter powders in dry, 0-100% hydrogen-nitrogen atmospheres. Manganese was mixed with the NC 100·24 sponge iron powder as low carbon ferromanganese and carbon as a graphite addition. Dogbone compacts were pressed at 660 MPa, the sintering temperatures were 1120 and 1250°C and cooling rates ∼65 K min- 1. In specimens sintered in nitrogen containing atmospheres at 1120°C, final carbon content was ∼0·7% and for those processed at 1250°C ∼0·6%. Sintering in dry hydrogen resulted in lower carbon and oxygen contents. Independent of the H2/N2 ratio in the furnace atmosphere, however, all the specimens were ductile and exhibited similar strengths. Yield strengths R 0·2 were in the range: 426-464 MPa, tensile strengths Rm were 724-780 MPa and strains to failure were 1·6-2·0% after sintering at 1250°C. The 1120°C sintering temperature resulted in 10-15% lower strength values. The microstructures, significantly devoid of oxide networks, comprised mainly mixtures of bainite and fine (divorced) pearlite, with very little martensite and retained austenite. Reproducibly successful sintering of manganese containing compacts requires that reduction conditions exist at the sintering temperature. Ellingham Richardson diagrams dictate that the dewpoints of hydrogen required are-55 and-40°C at 1120 and 1250°C, respectively. A semiclosed container, how ever, ensures a different microclimate. It is suggested that then the initial relevant reactions there are: Mn[vapour]+H2O=MnO+H2, 3Fe2O3 +H2= 2Fe3O4+H2O, Fe3O4+H2=3FeO+H2O, FeO+H2= Fe+H2O and C+O2=CO2, which provide hydrogen andwater vapour,also within the pores. The manganese vapour further acts as a ‘shield’ by generating further hydrogen from the water vapour. The following reactions involving carbon monoxide are postulated above 927°C, when CO is a more effective reducing agent than hydrogen: C+H2O=H2+CO, 3Fe2O3+ CO=2Fe3O4+CO2, Fe3O4+CO=3FeO+CO2, FeO+CO=Fe+CO2 and C+CO2=2CO. Accordingly, irrespective of whether it is hydrogen or nitrogen in the semiclosed container, if there is a supply of carbon, reducing conditions prevail at the sintering temperature,embrittling oxidenetworks arenot formed and ductile manganese steels are processed.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project. / Assisted by C. R. Fillerup and L. L. Bates / Edited and Revised by H. C. Heard

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<p>The aim of this project is to characterise novel psychrotrophic actinomycetes isolated from Antarctic Dry Valley soils and to isolate and characterize secondary metabolites produced by these actinomycetes.</p>

Top Choice (n = 48) and Select (n = 48) paired bone-in ribeye rolls, bone-in strip loins, and boneless top sirloin butts were assigned randomly to one of two aging treatments (dry or wet) and aged 14, 21, 28 or 35 days. Sensory and Warner-Bratzler shear (WBS) evaluation was conducted to determine palatability characteristics. WBS values and consumer ratings showed wet-aged ribeye steaks to be more tender than their dry-aged counterparts. WBS values for ribeye and top sirloin steaks decreased with increased aging time. Consumer ratings for tenderness like increased with increased aging time for beef steaks from all three subprimals. No significant differences were found for consumer evaluation of top sirloin steaks. Top Choice ribeye and top loin steaks received higher consumer ratings for overall like and juiciness attributes when compared to Select steaks. Cutting tests were performed at the end of each aging period to determine retail yields and processing times. Retail cutting tests showed dry-aged subprimals had lower total saleable yield percentages and increased processing times compared to wet-aged subprimals. Cooler shrink and gross cut loss percentages increased with increased aging time for both Top Choice and Select subprimals.

ABSTRACT Because of a great variety of tribocomponents and lubricants, the phenomenon of frictional magnetization and electrification between tribocomponents becomes more obvious. In order to understand the effects of frictional magnetization and electrification on tribology characteristics and miniature electrical control component signal, the frictional magnetization and electrification test under dry friction condition is investigated by the reciprocating electrification tester. Three material-pair types will be investigated their frictional magnetization and electrification behavior under various operating parameters, e.g. driver speed, normal load, and sliding distance. Moreover, the worn surface will be observed by the optical microscopy and SEM. Results show that the magnetization and electrification on friction surfaces increases with increasing load, and decreases with the carbon content of a material, and depends on material-pair. It is found that wear particles have been magnetized on the friction surface, even that the wear particles has been adhered to the surface caused by electro static action. Moreover, in the microscopic view, the frictional magnetization and electrification are related to both friction and wear.