scholarly journals Southern Methodist University Radiocarbon Date List I

Radiocarbon ◽  
1974 ◽  
Vol 16 (3) ◽  
pp. 368-380 ◽  
Author(s):  
Vance Haynes ◽  
Herbert Haas
Keyword(s):  
Carbon Dioxide ◽  
Liquid Nitrogen ◽  
Chromic Acid ◽  
Radiocarbon Date ◽  
Synthesis System ◽  
Southern Methodist University ◽  
Geological Sciences

The SMU Radiocarbon Laboratory is operated by the Department of Geological Sciences within the Institute for the Study of Earth and Man. One laboratory room contains the benzene synthesis system where samples are pretreated and converted to CO2 in a standard way and gas is purified after the procedures of Broecker (1957) by passage through hot CuO, 10% AgNO3 solution, chromic acid, hot copper, and P2O5 via cryogenic pumping with liquid nitrogen. Purified CO2 is then converted to Li2C2 which is hydrolized to C2H2 and converted to C6H6 catalytically following the procedures of Noakes et al (1966). Carbon dioxide and benzene yields are routinely in excess of 90% in both cases.

scholarly journals The Use of Cryogenic Temperature Gas Chromatography for the Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
G.P. Morie ◽  
C.H. Sloan
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Liquid Nitrogen ◽  
Cigarette Smoke ◽  
Cryogenic Temperature ◽  
Chromatographic Method ◽  
Porapak Q ◽  
Gas Chromatographic Method

AbstractA gas chromatographic method for the determination of carbon monoxide and carbon dioxide in cigarette smoke was developed. A column containing Porapak Q packing and a cryogenic temperature programmer which employed liquid nitrogen to cool the column to subambient temperatures was used. The separation of N

scholarly journals Southern Methodist University Radiocarbon Date List II

Radiocarbon ◽  
1975 ◽  
Vol 17 (3) ◽  
pp. 354-363 ◽  
Author(s):  
Herbert Haas ◽  
Vance Haynes
Keyword(s):  
Copper Oxide ◽  
Liquid Scintillation ◽  
Original System ◽  
Radiocarbon Date ◽  
Fossil Bone ◽  
Dry Ice ◽  
Cleaning System ◽  
Southern Methodist University ◽  
Gas Volume

All samples described in this date list have been dated from November 1973 to January 1975. Only the benzene liquid scintillation installation was used during this time. For the combustion of soil and fossil bone samples containing a high content of sulfur (ie, in the form of pyrite), a new CO2 extraction and cleaning system was built. The gases released by the combustion are dried in ice and dry ice traps, passed through hot copper oxide and bubbled through KOH solution. Following the combustion, the K2CO3 precipitate is acidified in the same vessel where it formed and the released CO2 is again dried in a dry ice trap and by passing it through ascarite. This CO2 gas is quite clean and can be brought to the original system where the gas volume is measured. Further processing is as previously described (Haynes and Haas, 1974).

scholarly journals Tata Institute Radiocarbon Date List VI

Radiocarbon ◽  
1969 ◽  
Vol 11 (01) ◽  
pp. 188-193 ◽  
Author(s):  
D. P. Agrawal ◽  
Sheela Kusumgar
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Radiocarbon Date ◽  
Tata Institute ◽  
Atmospheric Carbon

This date list is comprised of archaeologic and geophysical samples. The latter are in continuation of our investigations of bomb-produced radiocarbon in atmospheric carbon dioxide reported in Tata V. We continue to count samples in the form of methane; the techniques used have been described elsewhere (Agrawalet al., 1965).

Southern Methodist University Radiocarbon Date List III

Radiocarbon ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 209-238 ◽  
Author(s):  
Herbert Haas
Keyword(s):  
North America ◽  
Radiocarbon Date ◽  
Initial Series ◽  
Southern Methodist University

The dates presented in this list were determined between June 1974 and October 1983. They relate to projects in North America and in Algeria. Dates with numbers prior to SMU-500 have generally no correction for fractionation. Following this initial series of dates an increasing number of δ13C/12C measurements were made by an outside laboratory, especially if the submitter requested a fractionation correction or if the sample was of carbonate or bone.

Measurement of Rake Face Temperature in Cryogenic Machining of Titanium Alloy

2020 ◽  
Author(s):  
Masahiko Sato ◽  
Masashi Kamoto
Keyword(s):  
Carbon Dioxide ◽  
Titanium Alloy ◽  
Optical Fiber ◽  
Liquid Nitrogen ◽  
Cutting Tool ◽  
Weight Ratio ◽  
Rake Face ◽  
Cryogenic Machining ◽  
Tool Insert ◽  
Face Temperature

Abstract Titanium alloys are widely used as mechanical components, since they have superior properties such as high strength-to-weight ratio. They are regarded as difficult-to-cut materials. Their low thermal conductivity increases the temperature near the cutting edge, which causes excessive tool wear during cutting. Recently, many studies on cryogenic machining have been conducted. Cryogenic machining has emerged as an environmentally friendly alternative to traditional emulsion coolants. In this study, the rake face temperatures of cutting tool in the turning of titanium alloy under dry, soluble coolant, cryogenic carbon dioxide coolant and liquid nitrogen coolant conditions were measured to clarify the effect of coolant on cutting temperature. Turning tests were performed using a precision lathe. Tool insert was made by a translucent alumina. A small hole was drilled into the tool insert. An infrared radiation pyrometer with an optical fiber was used. The optical fiber was inserted into the hole. During chip formation, the infrared rays, radiated from the tool-chip interface and transmitted through the cutting tool, were accepted and transmitted by the optical fiber. The effects of cryogenic coolant on the rake face temperature were investigated. The rake face temperatures under carbon dioxide cooling and liquid nitrogen cooling were approximately 60 °C and 90 °C lower than that in dry cutting, respectively.

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