Aqueous Film-Forming Foam Treatment under Alkaline Hydrothermal Conditions

2022 ◽  
Vol 148 (2) ◽  
Author(s):  
Brian R. Pinkard
Keyword(s):  
Hydrothermal Conditions ◽  
Film Forming

Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

1967 ◽  
Vol 25 ◽  
pp. 366-367
Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
High Altitude ◽  
Amyl Acetate ◽  
Temperature Variations ◽  
Film Forming ◽  
Film Specimen ◽  
Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 314-315
Author(s):  
Earl R. Walter ◽  
Glen H. Bryant
Keyword(s):  
Sample Preparation ◽  
High Vacuum ◽  
Vacuum System ◽  
Latex Particles ◽  
New Methods ◽  
Diffusion Pump ◽  
Film Forming ◽  
Routine Basis ◽  
Distribution Studies ◽  
Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

Dynamics of CO2 emission from chernozems under agricultural use

2017 ◽  
Vol 4 (3) ◽  
pp. 43-49
Author(s):  
M. Miroshnychenko ◽  
O. Siabruk
Keyword(s):  
Carbon Dioxide ◽  
Agricultural Practices ◽  
Growing Season ◽  
Warm Period ◽  
Direct Seeding ◽  
Soil Tillage ◽  
Plant Residues ◽  
Hydrothermal Conditions ◽  
Organic Mineral ◽  
Mineral System

Aim. The comparison of the effect of hydrothermal conditions and various agricultural practices on the emission of CO 2 from chernozems in the Left-Bank Forest-Steppe of Ukraine. Methods. The dynamics of the intensity of carbon dioxide emissions from chernozem calcic (typical chernozem – in Ukrainian classifi cation) was studied during the growing season of 2011–2012. The observations were based on two fi eld experiments with various methods of soil till- age (6–7 years from the beginning of the experiment) and fertilization systems (21–22 years from the beginning of the experiment). Particularly, plowing at 20–22 cm, disking at 10–12 cm, cultivation at 6–8 cm and direct seeding using Great Plains drill were studied among the soil tillage methods. Mineral system (N 45 P 50 K 45 ), organic system (manure 8 t/ha) and combined organic-mineral system (manure 8 t/ha + N 45 P 50 K 45 ) were studied among fertilization systems. The intensity of CO 2 fl ux was determined using the non-stationary respiratory chambers by the alkaline absorption method, with averaging of the results during the day and the frequency of once a month. Results. During the warm period, the emission of carbon dioxide from the soil changes dynamically depending on temperature and humidity. The maximum of emission coincides with the periods of warm summer showers in June-July, the minimum values are characteristic for the late autumn period. The total emission losses of carbon in chernozems over the vegetation period ranged from 480 to 910 kg/ha and varied depending on the methods of tillage ± (4.0–6.0) % and fertilization systems ± (3.8–7.1) %. The changes in the intensity of CO 2 emission from the soil under different methods of soil tillage are associated with hydrothermal regime and the depth of crop residues location. The biggest difference is observed im- mediately after tillage, but in the spring period the differences are only 12–25 %, and after drying of the top layer of soil become even less. Direct seeding technology provides the greatest emission of CO 2 from chernozem, which is fa- cilitated by better water regime and more complete mineralization of plant residues on the soil surface. Annual losses of carbon are the least under disking of soil at 10–12 cm. The changes in the intensity of CO 2 emission from the soil under different fertilization systems are associated with the involvement of the additional organic matter from plant residues and manure to the microbiological decomposition. The greatest emission was observed under the organic- mineral fertilization system, which increased the loss of carbon by 7–8 % in comparison with the mineral system in the unfavorable hydrothermal year and by 11–15 % in the more favorable year. These differences are observed mainly during the fi rst half of the growing season when there is a clear tendency to increase the intensity of soil respiration. Conclusions. The hydrothermal conditions of the warm period of the year are decisive in the formation of the CO 2 emission fl ow from chernozems. Due to the improvement of agricultural practices, emissions might be reduced but not more that by 15 % of natural factor contribution.

A common precursor to both prebiotic and biological pathways to RNA nucleotides

2018 ◽  
Author(s):  
Andrea Pérez-Villa ◽  
Thomas Georgelin ◽  
Jean-François Lambert ◽  
Marie-Christine Maurel ◽  
François Guyot ◽  
...  
Keyword(s):  
Enzymatic Synthesis ◽  
De Novo ◽  
Life Forms ◽  
Hydrothermal Conditions ◽  
Modern Life ◽  
Ab Initio Simulations ◽  
Spontaneous Formation ◽  
Common Precursor ◽  
Open Issue ◽  
Anomeric Carbon

Understanding the mechanism of spontaneous formation of ribonucleotides under realistic prebiotic conditions is a key open issue of origins-of-life research. In cells, <i>de novo</i> and salvage nucleotide enzymatic synthesis combines 5-phospho-α -D-ribose-1-diphosphate ( α-PRPP) and nucleobases. Interestingly, these reactants are also known as prebiotically plausible compounds. Combining ab initio simulations with mass spectrometry experiments, we compellingly demonstrate that nucleobases and α -PRPP spontaneously combine, through the same facile mechanism, forming both purine and pyrimidine ribonucleotides, under mild hydrothermal conditions. Surprisingly, this mechanism is very similar to the biological one, and yields ribonucleotides with the same anomeric carbon chirality as in biological systems. These results suggest that natural selection might have optimized – through enzymes – a pre-existing ribonucleotide formation mechanism, carrying it forward to modern life forms.

A common precursor to both prebiotic and biological pathways to RNA nucleotides

2017 ◽  
Author(s):  
Andrea Pérez-Villa ◽  
Thomas Georgelin ◽  
Jean-François Lambert ◽  
Marie-Christine Maurel ◽  
François Guyot ◽  
...  
Keyword(s):  
Enzymatic Synthesis ◽  
De Novo ◽  
Life Forms ◽  
Hydrothermal Conditions ◽  
Modern Life ◽  
Ab Initio Simulations ◽  
Spontaneous Formation ◽  
Common Precursor ◽  
Open Issue ◽  
Anomeric Carbon

Understanding the mechanism of spontaneous formation of ribonucleotides under realistic prebiotic conditions is a key open issue of origins-of-life research. In cells, <i>de novo</i> and salvage nucleotide enzymatic synthesis combines 5-phospho-α -D-ribose-1-diphosphate ( α-PRPP) and nucleobases. Interestingly, these reactants are also known as prebiotically plausible compounds. Combining ab initio simulations with mass spectrometry experiments, we compellingly demonstrate that nucleobases and α -PRPP spontaneously combine, through the same facile mechanism, forming both purine and pyrimidine ribonucleotides, under mild hydrothermal conditions. Surprisingly, this mechanism is very similar to the biological one, and yields ribonucleotides with the same anomeric carbon chirality as in biological systems. These results suggest that natural selection might have optimized – through enzymes – a pre-existing ribonucleotide formation mechanism, carrying it forward to modern life forms.

Modern devices for treatment of the surgeon’s hands and the surgical field (literature review)

2020 ◽  
pp. 41-50
Author(s):  
Artem Mikhailovich Morozov ◽  
◽  
Alexey Nikolaevich Sergeev ◽  
Gennady Alexandrovich Dubatolov ◽  
Nikolay Alexandrovich Sergeev ◽  
...  
Keyword(s):  
Cost Effective ◽  
Surgical Infection ◽  
Operating Field ◽  
Functional Additives ◽  
Literary Sources ◽  
Film Forming ◽  
Key Points ◽  
Surgical Field ◽  
Ammonium Compounds ◽  
Active Substances

The aim – analyze modern Russian and foreign literary sources in order to determine modern means for treating the hands of the surgeon and the operating field. Results. One of the key points in the prevention of surgical infection is the treatment of the surgeon’s hands and the operating field with effective skin antiseptics in order to destroy pathogenic and opportunistic microorganisms that colonize intact skin. In modern practice, skin antiseptics are predominantly used containing alcohols as active substances, in particular ethyl, propyl and isopropyl, halogenated substances such as iodine and iodophores, guanidines, which include chlorhexidine digluconate, as well as quaternary ammonium compounds. Moreover, the most widespread are combined preparations containing several active substances and functional additives, which makes it possible to neutralize the negative properties of various active substances. Also, an interesting and promising direction is the use of polymer operating films or film-forming antiseptics. Currently, research is being actively carried out aimed at finding and developing modern highly effective antiseptic agents and their rational combinations that meet the necessary requirements, are optimal in their properties, cost-effective and comfortable to use.

Effect of plant film-forming anti-transpirant on transpiration efficiency of winter wheat flag-leaf

2012 ◽  
Vol 19 (5) ◽  
pp. 1091-1095
Author(s):  
Chang-Hai SHI ◽  
Shao-Hua KONG ◽  
Hong-Mei ZHAI ◽  
Jing YANG ◽  
Dong-Xiao LI ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Flag Leaf ◽  
Transpiration Efficiency ◽  
Film Forming
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