Quantitative DTA under a changed gas atmosphere

1979 ◽  
Vol 17 (2) ◽  
pp. 305-309 ◽  
Author(s):  
W. Balcerowiak ◽  
Cz. Latocha
Keyword(s):  
Gas Atmosphere ◽  
Quantitative Dta

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.

Investigations of the corrosion activity of the KAlCl4 melts by the methods of physicochemical analysis

2019 ◽  
Vol 24 (4) ◽  
pp. 59-66
Author(s):  
E.S. Filatov
Keyword(s):  
Water Vapor ◽  
Hydrochloric Acid ◽  
Input Data ◽  
Corrosion Potential ◽  
Physicochemical Analysis ◽  
Metal Alloys ◽  
Corrosion Activity ◽  
Protection Efficiency ◽  
Gas Atmosphere ◽  
Metal Aluminum

Corrosion behavior of metal alloys in a melt of potassium chloroaluminate (KAlCl4) was investigated. Metal aluminum was used as a protector for protection against continuous frontal corrosion. The equilibrium potentials of aluminum and the corrosion potential of the alloys were measured. The data were obtained to evaluate the corrosion ability of the system of molten salt of potassium chloroaluminate - gas (argon) by measuring the redox potential of the specified environment depending on the composition of the gas atmosphere above it, i.e. from impurities of water vapor, hydrochloric acid, oxygen and other, for example, carbonaceous gases. The calculations of the protection efficiency using the potential difference between the metal aluminum and the protected material were performed. The regularities of changes in the equilibrium potentials of aluminum from the temperature and concentration were established as the fundamental data for possible use at determining the composition ratio of potassium chlorides and aluminum in potassium chloroaluminate as input data for the development of a sensor of composition of chloroaluminate potassium.

Pilot Test of Olefin Synthesis from Dimethyl Ether in a Synthesis Gas Atmosphere

2021 ◽  
Author(s):  
Maria V. Magomedova ◽  
Mikhail I. Afokin ◽  
Anastasiya V. Starozhitskaya ◽  
Ekaterina G. Galanova
Keyword(s):  
Dimethyl Ether ◽  
Synthesis Gas ◽  
Pilot Test ◽  
Olefin Synthesis ◽  
Gas Atmosphere

Growth of Salmonella typhimurium and Mesophilic Organisms on Beef Steaks as Influenced by Type of Packaging1,2

1982 ◽  
Vol 45 (3) ◽  
pp. 263-267 ◽  
Author(s):  
L. S. LUITEN ◽  
J. A. MARCHELLO ◽  
F. D. DRYDEN
Keyword(s):  
Treatment Group ◽  
Salmonella Typhimurium ◽  
Vacuum Packaging ◽  
Gas Atmosphere ◽  
Beef Steaks ◽  
Retail Meat

Two trials, each utilizing 72 samples of fresh beef loin steak, were done to determine the effects of various packing systems upon growth of Salmonella typhimurium. Samples were inoculated with 105 cells/cm2 of the organism and randomly assigned to four packaging treatments: (1) overwrapping in oxygen-permeable film; (2) vacuum packaging; (3) packaging in barrier bags flushed with a 60% CO2: 40% O2 gas atmosphere then evacuated and sealed; and (4) packaging in barrier bags filled with a 60% CO2: 40% O2 gas atmosphere. Twelve steak samples were inoculated with S. typhimurium and 6 were uninoculated and served as a control in each treatment group. Samples were displayed in retail meat cases at 10 C for 3, 6 or 9 days, when they were evaluated for shrinkage and numbers of mesophilic organisms and S. typhimurium. Percent shrinkage was not affected (P>0.05) by packaging treatment. Counts of mesophilic organisms were similar (P>0.05) for vacuum- and gas-treated steaks, which were significantly lower (P<0.05) than counts from film overwrapped samples. Numbers of S. typhimurium increased significantly (P<0.05) during storage on samples wrapped with oxygen permeable film but remained low and fairly constant for vacuum- or gas-treated steaks. After 9 days of display, the film overwrapped steaks had greater (P<0.05) numbers of S. typhimurium than those of other treatments, whereas steaks held within the 60% CO2: 40% O2 gas atmosphere had lowest numbers overall.

Development of Cu Etching Using O$_{2}$ Cluster Ion Beam under Acetic Acid Gas Atmosphere

2012 ◽  
Vol 51 ◽  
pp. 08HA02 ◽  
Author(s):  
Takanori Suda ◽  
Noriaki Toyoda ◽  
Ken-ichi Hara ◽  
Isao Yamada
Keyword(s):  
Acetic Acid ◽  
Ion Beam ◽  
Acid Gas ◽  
Gas Atmosphere ◽  
Cluster Ion

Infrared Spectroscopy of Molten LiCl−KCl under Hydrogen Gas Atmosphere

2004 ◽  
Vol 108 (21) ◽  
pp. 4567-4569 ◽  
Author(s):  
Hironori Nakajima ◽  
Toshiyuki Nohira ◽  
Yasuhiko Ito
Keyword(s):  
Infrared Spectroscopy ◽  
Hydrogen Gas ◽  
Gas Atmosphere

Internal gas atmospheres, ethanol, and leakage of electrolytes from a flood-tolerant and a flood-susceptible sweet potato cultivar as influenced by anaerobiosis

1983 ◽  
Vol 61 (12) ◽  
pp. 3399-3404 ◽  
Author(s):  
Ling A. Chang ◽  
Larry K. Hammett ◽  
David M. Pharr
Keyword(s):  
Sweet Potato ◽  
Electrolyte Leakage ◽  
Potato Cultivar ◽  
Enriched Environment ◽  
Potato Cultivars ◽  
Susceptible Cultivar ◽  
Low Concentrations ◽  
Gas Atmosphere ◽  
High Concentrations

The postanaerobic behavior of sweet potato roots from a flood-tolerant cultivar, 'Centennial,' and a flood-susceptible cultivar, 'Caromex,' was studied. High concentrations of CO2 and low concentrations of O2 were present in the internal atmosphere of 'Caromex' roots even after the anaerobically pretreated roots were restored to air for a few days, whereas in 'Centennial,' the internal gas atmosphere was less affected by anoxia. Ethanol accumulation in 'Caromex' was consistently higher than in 'Centennial,' and the postanaerobic changes were different between cultivars. An inducation of electrolyte leakage was observed from both cultivars immediately after roots were exposed to a CO2-enriched environment for 48 h. The leakage became greater in 'Caromex' after a 3-day aerobic exposure. In 'Centennial,' leakage of electrolytes due to CO2 treatment diminished at the end of 3 days. Application of ethanol to the discs had no immediate effect on electrolyte leakage in either cultivar under a N2 environment. However, anaerobiosis alone resulted in higher electrolyte leakage. It remains to be determined that the postanaerobic patterns of 'Caromex' and 'Centennial' are characteristic of flood-susceptible and flood-tolerant sweet potato cultivars in general.

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