U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Subject term gases Remove constraint Subject term: gases Text availability Citation in PubAg Remove constraint Text availability: Citation in PubAg
Start Over

Search

11,535  Search Results

« Previous | 1 - 20 of 11,535 |
Number of results to display per page

Search Results

1. A Way of Sampling Soil Gases in Dense Subsoils, and some of Its Advantages and Limitations

Author:
Damon Boynton; Walter Reuther
Source:
Soil Science Society of America journal 1939 v.3 no.C pp. 37-42
ISSN:
0361-5995
Subject:
aeration; bottles; carbon dioxide; gases; mercury; soil air; soil heterogeneity; soil texture
Abstract:
... Summary and ConclusionsAlthough it is being used successfully in light soils, the method described in this paper is particularly valuable for seasonal studies of the aeration of dense subsoils. Use of the sampling well makes it possible to obtain samples of gases when these subsoils are almost saturated with water and it is impossible to get samples by other methods. The fact that the sampling loc ...
DOI:
10.2136/sssaj1939.036159950003000C0007x

2. Factors affecting the resistance of the flour beetle, tribolium confusum duv., to hydrogen cyanide1

Author:
GOUGH, H.C.
Source:
Annals of applied biology 1939 v.26 no.3 pp. 533-571
ISSN:
0003-4746
Subject:
Tribolium confusum; adults; cotton; eggs; flour; fumigants; fumigation; gases; hydrogen cyanide; insects; metabolism; progeny; pupae; toxic substances; toxicity
Abstract:
... 1 Two types of apparatus for exposing insects to known concentrations of toxic gases, under controlled conditions, were constructed and are described. 2 The relative resistance of different stages of the flour beetle, Tribolium confusum Duv., to hydrogen cyanide was determined, the results being treated by Bliss's method. The order of resistance was pupa (most resistant), adult, larva, egg. The di ...
DOI:
10.1111/j.1744-7348.1939.tb06988.x

3. A Theory on the Soil Atmosphere in and around a Hemisphere in Which Soil Gases Are Used or Released

Author:
C. H. M. van Bavel
Source:
Soil Science Society of America journal 1952 v.16 no.2 pp. 150-153
ISSN:
0361-5995
Subject:
gases; partial pressure; root systems; soil air
Abstract:
... If the root system of a plant is taken as approximately hemispherical it is of interest to compute the distribution of partial pressures of soil gases. This can be done by assuming that these gases are taken up, or released, at a constant rate throughout the hemisphere and also that the physical condition of the soil with regard to diffusion is uniform. Inside the hemisphere the solution is a simp ...
DOI:
10.2136/sssaj1952.03615995001600020010x

4. A Diffusion-Equilibrium Method for Obtaining Soil Gases under Field Conditions

Author:
George S. Taylor; J. H. Abrahams
Source:
Soil Science Society of America journal 1953 v.17 no.3 pp. 201-206
ISSN:
0361-5995
Subject:
absorption; equations; gases; laboratory experimentation; mass flow; mixing; oxygen; partial pressure; soil air; soil depth; soil water content
Abstract:
... A soil gas sample obtained by mass flow of gases may not be representative of the point sampled because of mixing with gases from other soil depths or from the atmosphere. The authors have investigated a method which eliminates this error and which is based on the diffusion of gases between a point in the soil to a collection chamber via a tube tightly fitted in the soil. A physical analysis and l ...
DOI:
10.2136/sssaj1953.03615995001700030005x

5. A Theory of Flame-Retardant Finishes

Author:
Irvin M. Gottlieb
Source:
Textile research journal 1956 v.26 no.2 pp. 156-167
ISSN:
0040-5175
Subject:
cellulose; durability; fabrics; finishes; flame retardants; flammability; gases; halogens; laundry; textile fibers
Abstract:
... A survey of the newer flame retardants suggests a simple theory for their constitu tion. The molecule should be water-insoluble to achieve durability in laundering. A solvent-soluble organic molecule is therefore proposed. The ortho-phosphate group should be present in the molecule to dehydrate catalytically the cellulose substrate. The molecule should contain polymerizable groups to effect a perm ...
DOI:
10.1177/004051755602600213

6. Electric Network Analog Study of Viscous Flow Normal to Parallel, Evenly Spaced Cylinders

Author:
J. Lowen Shearer
Source:
Textile research journal 1959 v.29 no.6 pp. 467-476
ISSN:
0040-5175
Subject:
electrical resistance; equations; fabrics; flow resistance; gases; porosity; prediction; textile fibers
Abstract:
... In connection with the study of viscous flow of liquids and gases between textile fibers, an electric resistance network analog was employed to solve the Navier-Stokes equations for creeping flow normal to an infinite array of circular cylinders arranged in a hexagonal pattern. The results of the analog study predict flow resistances approximately four times as great as those measured with real pa ...
DOI:
10.1177/004051755902900602

7. Gaseous Nitrogen Losses from Nitrogen Fertilized Soils Measured With Infrared and Mass Spectroscopy

Author:
R. A. Schwartzbeck; J. M. MacGregor; E. L. Schmidt
Source:
Soil Science Society of America journal 1961 v.25 no.3 pp. 186-189
ISSN:
0361-5995
Subject:
ammonium; ammonium chloride; ammonium nitrate; fertilizers; gases; infrared spectroscopy; mass spectrometry; nitric acid; nitrogen; nitrous oxide; soil properties; soil types; spectrometers; urea
Abstract:
... The evolution of nitrogen gases from four soils was studied by total soil nitrogen analysis, the mass spectrometer with N¹⁵-labeled nitrogen carriers, and with infrared spectroscopy. The type and amount of nitrogen gas evolved was influenced by a number of factors. Soil type was important in that the Nicollet and Fargo soils resulted in the evolution of more N₂ and N₂O than did the Fayette and Lar ...
DOI:
10.2136/sssaj1961.03615995002500030014x

8. Organic Matter Decomposition as Influenced by Oxygen Level and Flow Rate of Gases in the Constant Aeration Method

Author:
J. F. Parr; H. W. Reuszer
Source:
Soil Science Society of America journal 1962 v.26 no.6 pp. 552-556
ISSN:
0361-5995
Subject:
aeration; carbon; carbon dioxide; carbon dioxide production; gases; laboratory experimentation; microbial activity; organic matter; oxygen; soil; wheat straw
Abstract:
... Laboratory experiments were conducted to determine the rate of decomposition of wheat straw added to soil when continuous aeration was conducted with N₂-O₂ gas mixtures containing 0, 0.5, 1.0, 2.5, 5.0, and 21% oxygen at flow rates of ⅛, ¼, ½, 1, and 2 liters per hour. Rates of decomposition and total decomposition were followed by determination of wheat straw carbon evolved as CO₂. Total decompos ...
DOI:
10.2136/sssaj1962.03615995002600060012x

9. 6,6′-Disulfide Cross-Links in Cotton Cellulose; Part II: Effects of Different Cross-Linking Conditions

Author:
Robert F. Schwenker; Leonard Lifland
Source:
Textile research journal v.33 no.2 pp. 107-117
ISSN:
1746-7748
Subject:
cellulose; cotton; cotton fabric; crosslinking; gases; oxidation; textile fibers
Abstract:
... The effects of covalent, intermolecular cross-linking resulting from the introduction into cellulose of thio (SH) groups which are subsequently oxidized to form disulfide (S—S) linkages between the cellulose chains are discussed. When the reactions described herein are carried out on cotton fabrics, there is enhanced wet and/or dry wrinkle recovery, depending upon the mode of thio group oxidation. ...
DOI:
10.1177/004051756303300203

10. Sequence of Products Formed During Denitrification in Some Diverse Western Soils

Author:
Grant S. Cooper; R. L. Smith
Source:
Soil Science Society of America journal 1963 v.27 no.6 pp. 659-662
ISSN:
0361-5995
Subject:
acid soils; alfalfa; alkaline soils; denitrification; field capacity; gas chromatography; gases; nitrites; nitrogen; nitrous oxide; potassium nitrate; temperature
Abstract:
... The sequential products of anaerobic denitrification were determined on seven Western soils (four alkaline, two acid, and one neutral) by soil and gas analysis. The soils with 1% alfalfa and added KNO₃ were incubated at moistures slightly greater than field capacity and with an atmosphere of He. The soils and gases were periodically analyzed and balance sheets prepared. The sequence of NO₃⁻ → NO₂⁻ ...
DOI:
10.2136/sssaj1963.03615995002700060027x

11. Nitrosation of Soil Organic Matter: I. Nature of Gases Evolved During Nitrous Acid Treatment of Lignins and Humic Substances

Author:
F. J. Stevenson; R. J. Swaby
Source:
Soil Science Society of America journal 1964 v.28 no.6 pp. 773-778
ISSN:
0361-5995
Subject:
acid treatment; aromatic acids; carbon dioxide; decarboxylation; ethers; fulvic acids; gases; lignin; nitrites; nitrogen; nitrous acid; nitrous oxide; polyphenols; soil organic matter
Abstract:
... Manometric and infrared studies of the gaseous products formed by reacting HNO₂ with humic and fulvic acids, lignins. lignin-building units, and polyphenols showed the presence of N₂, N₂O, and CO₂. In addition, methyl nitrite (CH₃ONO) occurred in the gases obtained from lignins and certain phenolic derivatives. The CH₃ONO originated through dismutation of phenolic ethers; the CO₂ from decarboxylat ...
DOI:
10.2136/sssaj1964.03615995002800060027x

12. Oxygen Requirements of Cotton Seedling Roots for Penetration of Compacted Soil Cores

Author:
J. L. Tackett; R. W. Pearson
Source:
Soil Science Society of America journal 1964 v.28 no.5 pp. 600-605
ISSN:
0361-5995
Subject:
Gossypium; bulk density; carbon dioxide production; compacted soils; cotton; gases; oxygen; root growth; roots; seedlings; soil water content; subsoil; water uptake
Abstract:
... Cotton root growth and activity was determined at different levels of subsoil bulk density and O₂ concentration. Subsoil cores of desired bulk density were aerated leaving both the soil moisture content intact and the surface soil exposed to diffusion of gases from the atmosphere. Measurements of root growth and activity in the subsoils included depth of root penetration, root yield, water uptake, ...
DOI:
10.2136/sssaj1964.03615995002800050010x

13. A Semimicro Technique for Studying the Oxygen Content of Gases

Author:
Theron G. Sommerfeldt; Kenneth W. Knutson
Source:
Soil Science Society of America journal 1965 v.29 no.2 pp. 224-225
ISSN:
0361-5995
Subject:
gases; oxygen; portable equipment; soil science
Abstract:
... A simple, compact, portable, and relatively durable instrument has been devised whereby the oxygen content of semimicro quantities of gases can be accurately and rapidly determined. A Beckman D-2 oxygen analyzer is connected to a vacuum pump via a 3-way valve in a way that the system can be evacuated. The evacuation process makes it possible to analyze a gas sample of less than 20 cc where 500- to ...
DOI:
10.2136/sssaj1965.03615995002900020034x

14. Root Growth Through Porous Media Under Controlled Conditions II. Effect of Aeration Levels and Rigidity

Author:
G. M. Aubertin; L. T. Kardos
Source:
Soil Science Society of America journal 1965 v.29 no.4 pp. 363-365
ISSN:
0361-5995
Subject:
Zea mays; corn; gases; oxygen; porous media; root growth; root systems; seedlings; soil air
Abstract:
... The effect of four different compositions of aeration gases on the root growth of maize seedlings (Zea mays) grown in rigid and nonrigid systems of a given pore diameter was evaluated. Best root growth of maize seedlings occurred where the aerating gas contained 10% oxygen rather than 21%. Root growth at 5% oxygen and 21% oxygen were similar but at 2.5% oxygen root growth was markedly decreased. A ...
DOI:
10.2136/sssaj1965.03615995002900040007x

15. Nitrosation of Soil Organic Matter: II. Gas Chromatographic Separation of Gaseous Products

Author:
F. J. Stevenson; R. M. Harrison
Source:
Soil Science Society of America journal 1966 v.30 no.5 pp. 609-612
ISSN:
0361-5995
Subject:
carbon dioxide; carbon monoxide; charcoal; coconuts; gas chromatography; gases; hydrogen; nitric oxide; nitrites; nitrogen; nitrous oxide; oxygen; soil; soil organic matter; sorption
Abstract:
... Gas chromatographic techniques were developed for separating and determining inorganic gases in experimental systems dealing with losses of soil N. A single column, consisting of acid-washed chromatographic-grade coconut charcoal, gave excellent resolution of H₂, N₂, CO, CO₂, N₂O, and NO (or O₂). The sensitivity of the method for NO and CO was improved considerably by blocking sorption sites respo ...
DOI:
10.2136/sssaj1966.03615995003000050022x

16. Changes in Internal Atmosphere of Submersed Vascular Hydrophytes in Relation to Photosynthesis

Author:
Richard T. Hartman; Doris L. Brown
Source:
Ecology 1967 v.48 no.2 pp. 252-258
ISSN:
0012-9658
Subject:
carbon dioxide; oxygen production; nitrogen; Ceratophyllum demersum; Elodea canadensis; light intensity; methane; carbon; oxygen; vascular plants; photosynthesis; gas chromatography; dissolved oxygen; aquatic plants; aquatic ecosystems
Abstract:
... Gases were extracted from the internal atmosphere of Elodea canadensis and Ceratophyllum demersum in a closed system under reduced pressure. The volume of extractable gases varied throughout the daily period. Gases separated and quantitatively measured by gas chromatography included CO₂, O₂, N₂, and CH₄. Results from diurnal studies showed a lag between peak values for dissolved oxygen in the surr ...
DOI:
10.2307/1933107

17. Irradiation induced gases in packaged foods. I. Identification and measurements

Author:
Pratt, G.B.; Kneeland, L.E.; Heiligman, F.; Killoran, J.J.
Source:
Journal of food science 1967 v.32 no.2 pp. 200-205
ISSN:
0022-1147
Subject:
foods; food packaging; gamma radiation; dose response; temperature; gases
DOI:
10.1111/j.1365-2621.1967.tb01293.x

18. Soil Atmosphere as Influenced by Temperature and Moisture

Author:
M. Yamaguchi; W. J. Flocker; F. D. Howard
Source:
Soil Science Society of America journal 1967 v.31 no.2 pp. 164-167
ISSN:
0361-5995
Subject:
carbon dioxide; densitometers; gamma radiation; gas chromatography; gases; nitrogen; oxygen; sandy loam soils; soil air; soil water; soil water content; temperature
Abstract:
... Composition of the atmosphere of Yolo sandy loam soil columns was determined at different depths and different soil moisture conditions. After saturation with water, soil columns were placed in 30, 25, 20, 15, or 10C constant temperature rooms and moisture was allowed to evaporate from the soil surface. Soil moisture content was determined with a gamma-ray densitometer; CO₂, O₂, and N₂ concentrati ...
DOI:
10.2136/sssaj1967.03615995003100020008x

19. Dense gas chromatography at pressures to 2000 atmospheres

Author:
Giddings, J.C.; Myers, M.N.; King, J.W.
Source:
Journal of chromatographic science 1969 v.7 no.5 pp. 276-283
ISSN:
0021-9665
Subject:
gas chromatography; gases; density; pressure
DOI:
10.1093/chromsci/7.5.276

20. Soil Perfusion under Controlled Conditions of Soil Moisture Content and Soil Atmospheric Composition

Author:
R. E. Wildung; J. W. Biggar; G. Chesters
Source:
Soil Science Society of America journal 1969 v.33 no.5 pp. 813-814
ISSN:
0361-5995
Subject:
aqueous solutions; atmospheric chemistry; atmospheric pressure; environmental factors; gases; soil water content
Abstract:
... A new soil perfusion system is described which allows the continuous recycling of an aqueous solution through a soil column under controlled environmental conditions. The system consists essentially of a perforated inner column for soil, jacketed by an outer column in which constant air pressure is maintained. Precise control of soil moisture content and soil atmospheric composition during perfusi ...
DOI:
10.2136/sssaj1969.03615995003300050051x