THE CATALYTIC DEHYDRATION OF ETHYL ALCOHOL BY ALUMINA. II.

1937 ◽  
Vol 15b (10) ◽  
pp. 438-446
Author(s):  
W. A. Alexander ◽  
W. R. Horn ◽  
L. A. Munro
Keyword(s):  
Water Content ◽  
Ethyl Alcohol ◽  
Commercial Alumina ◽  
Optimum Water Content ◽  
Optimum Water

The decomposition of ethyl alcohol by two different samples of commercial alumina at 318° and 450 °C. has been studied. The effect of time or previous use of the catalyst on the course of the reaction has been examined at 300° and 318 °C. It has been found that the course of the reaction changes with change in water content of the catalysts. For the particular alumina used, there is one optimum water content for the production of ether and another for ethylene. For catalysts initially high in water there is a change in the sense of the reaction with use. Ignited catalysts of zero water content are not inactive, but become less effective for dehydration; this favors the production of ether.

THE CATALYTIC DEHYDRATION OF ETHYL ALCOHOL BY ALUMINA: I. THE EFFECT OF THE WATER CONTENT OF THE CATALYST

1935 ◽  
Vol 12 (5) ◽  
pp. 707-710 ◽  
Author(s):  
L. A. Munro ◽  
W. R. Horn
Keyword(s):  
Water Content ◽  
Ethyl Alcohol ◽  
Optimum Water Content ◽  
Optimum Water ◽  
Alumina Catalysts

The dehydration of ethyl alcohol has been studied at 250 °C. using alumina catalysts differing in water content. There is an optimum water content for the greatest activity of the catalyst. The apparent poisoning is greatest for those catalysts having greatest activity. There is no apparent poisoning for a catalyst having zero water content. In no case was the course of the reaction changed.

Aspects of the behaviour of compacted clayey soils on drying and wetting paths

2002 ◽  
Vol 39 (6) ◽  
pp. 1341-1357 ◽  
Author(s):  
Jean-Marie Fleureau ◽  
Jean-Claude Verbrugge ◽  
Pedro J Huergo ◽  
António Gomes Correia ◽  
Siba Kheirbek-Saoud
Keyword(s):  
Water Content ◽  
Pore Water ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Dry Density ◽  
Clayey Soils ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

A relatively large number of drying and wetting tests have been performed on clayey soils compacted at the standard or modified Proctor optimum water content and maximum density and compared with tests on normally consolidated or overconsolidated soils. The results show that drying and wetting paths on compacted soils are fairly linear and reversible in the void ratio or water content versus negative pore-water pressure planes. On the wet side of the optimum, the wetting paths are independent of the compaction water content and can be approached by compaction tests with measurement of the negative pore-water pressure. Correlations have been established between the liquid limit of the soils and such properties as the optimum water content and negative pore-water pressure, the maximum dry density, and the swelling or drying index. Although based on a limited number of tests, these correlations provide a fairly good basis to model the drying–wetting paths when all the necessary data are not available.Key words: compaction, unsaturated soils, clays, drying, wetting, Proctor conditions.

Compacted soil behaviour through changes of density, suction, and stiffness of soils with remoulding water content

2018 ◽  
Vol 55 (2) ◽  
pp. 182-190 ◽  
Author(s):  
T.W. Zhang ◽  
Y.J. Cui ◽  
F. Lamas-Lopez ◽  
N. Calon ◽  
S. Costa D’Aguiar
Keyword(s):  
Water Content ◽  
Dry Density ◽  
Soil Plasticity ◽  
Optimum Water Content ◽  
Hydromechanical Behaviour ◽  
The Difference ◽  
Two Peaks ◽  
Soil Behaviour ◽  
Optimum Water ◽  
Water Contents

To better understand the overall hydromechanical behaviour of interlayer soil, the compaction behaviour of one of the two components — the portion of fines (<4 mm) that is sensitive to water content changes — was investigated. The standard Proctor compaction curves were first determined for the soils. Then, the maximum shear modulus, Gmax, and suction were measured on samples statically compacted at an identical dry density, but different remoulding water contents. The changes in Gmax reveal the existence of a characteristic water content corresponding to the maximum Gmax. The results also show that this characteristic water content increases with the soil plasticity, being similar to the variation trend of optimum water content with soil plasticity. A bimodal pattern was observed from the plot of total suction ψ versus the slope of water content w–log(ψ) curve. The suction corresponding to the maximum Gmax is close to the lowest point between the two peaks in the ψ–dw/dlog(ψ) curve. A reasonable explanation was attempted for the correspondence between the “optimum water content” defined by the maximum value of Gmax and the corresponding suction. The difference between the static and dynamic compactions was also explained in terms of suction values.

Mechanical Properties of Bentonite-Sand Mixtures Under Triaxial Stress Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
M. Umedera ◽  
A. Fujiwara ◽  
N. Yasufuku ◽  
M. Hyodo ◽  
H. Murata
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Compression Tests ◽  
Optimum Water Content ◽  
Triaxial Compression Tests ◽  
Optimum Water

AbstractA series of triaxial compression tests is being conducted under the drained condition on bentonite and sand mixtures, known as buffer, in saturated and optimum water content states to clarify the mechanical properties of the buffer.It was found that the mechanical properties of bentonite and sand mixtures are strongly influenced by water and bentonite contents: shear strength in a saturated state is less than that in an optimum water content state; shear strength decreases rapidly with increasing bentonite content. Strength properties are much dependent on confining pressure.

scholarly journals Research on the Optimum Water Content of Detecting Soil Nitrogen Using Near Infrared Sensor

Sensors ◽  
2017 ◽  
Vol 17 (9) ◽  
pp. 2045 ◽  
Author(s):  
Yong He ◽  
Shupei Xiao ◽  
Pengcheng Nie ◽  
Tao Dong ◽  
Fangfang Qu ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Nitrogen ◽  
Near Infrared ◽  
Infrared Sensor ◽  
Optimum Water Content ◽  
Optimum Water

Study on Reasonable Feature of Compaction Loess with Air Porosities

2012 ◽  
Vol 238 ◽  
pp. 441-446
Author(s):  
Jing Yang ◽  
Ling Hao Wang ◽  
Fu Li Ma ◽  
Xiao Hong Bai
Keyword(s):  
Quality Control ◽  
Water Content ◽  
Dry Density ◽  
Compression Coefficient ◽  
Optimum Water Content ◽  
Compaction Energy ◽  
Internal And External Factors ◽  
And Control ◽  
Compaction Method ◽  
Optimum Water

The degree of compaction is usually used as the compaction quality and control indicator of backfill in practical project. However, as the degree of compaction is affected by various internal and external factors, its accuracy is difficult to guarantee. In this paper, compacted loess samples were prepared under different compaction energies by normal compaction method. The curves of compression coefficient and dry density, the compression coefficient and porosity of compaction loess samples under different compaction energy are analyzed while the water content is constant. The air porosities of compaction loess samples under different compaction energy and water content are calculated and summed up. The air porosity of compaction loess samples under different compaction energy is more stable than the degree of compaction when the water content is exactly equal to the optimum water content. The rationality of using air porosity as the loess compaction quality control indicator is discussed. It is proposed using air porosity as additional indicator of compaction quality control on the condition of the loess compacted dry density meeting the requirements. The air porosity less than 6.5% is suggested as the additional quality control indictor for region backfill compaction.

Properties of Enzymatic Hydrolysis Corn Starch Sizing Agent Modified in Supercritical Carbon Dioxide

2011 ◽  
Vol 332-334 ◽  
pp. 2103-2107
Author(s):  
Yue Juan Wang ◽  
Hong Jun Fu
Keyword(s):  
Carbon Dioxide ◽  
Enzymatic Hydrolysis ◽  
Water Content ◽  
Supercritical Co2 ◽  
Corn Starch ◽  
Enzymatic Reaction ◽  
Variance Ratio ◽  
Optimum Water Content ◽  
Co2 Treatment ◽  
Optimum Water

This paper describes an experiment of Corn starch treatment with α-amylase under the condition of supercritical CO2 at 50°C, 11MPa, and investigates the effects of different water content on supercritical CO2 treatment of corn starch. The results demonstrate that the viscosity of the treated starch is much lower than that of untreated starch, as well as the variance ratio of the viscosity is up to 96%. The optimum water content for the degradation of the enzymatic reaction is 2%;when water content is up to 3%, the viscosity of the serosity is 5Mpa•s, and the sizing performance reaches the best.

scholarly journals Vibrating Compactability of Fly-Ash-Cement Mixtures Mixed with Optimum Water Content.

1999 ◽  
pp. 55-66
Author(s):  
Kazuto FUKUDOME ◽  
Shigeyoshi NAGATAKI ◽  
Mamoru SAKAMOTO ◽  
Tatsuo SUZUKI ◽  
Tatsuo KITA
Keyword(s):  
Fly Ash ◽  
Water Content ◽  
Optimum Water Content ◽  
Optimum Water ◽  
Cement Mixtures
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