Effect of Environmental Materials on Aqueous Corrosion of R7T7 Glass

1988 ◽  
Vol 127 ◽  
Author(s):  
N. Godon ◽  
E. Vernaz ◽  
J. H. Thomassin ◽  
J. C. Touray
Keyword(s):  
Atmospheric Pressure ◽  
Test Results ◽  
Aqueous Corrosion ◽  
Environmental Material ◽  
Environmental Materials ◽  
Activated Bentonite ◽  
Order Of Magnitude ◽  
Glass Specimen ◽  
Icp Analysis ◽  
Glass Behavior

ABSTRACTR7T7 glass behavior was investigated in contact with eleven different materials including smectites, bentonites, illites, granite and sand. The experiments were conducted at 90°C under atmospheric pressure with a 4 cm−1 SA/V ratio using two grams of material in double distilled water under static leaching conditions without renewal of the leachate. For each material a control test was conducted under the same conditions but without the glass specimen, as well as a series of tests on glass alone, without the environmental material. Kinetics studies lasting up to 364 days were performed on four selected materials.The test results (mass loss, ICP analysis of the leachates, SEM and TEM observations) showed relatively slight glass alteration in contact with sand, granite and one bentonite (i.e. the same order of magnitude as glass alone in deionized water), but greater alteration of glass in contact with all the other clays.The significant differences in glass behavior in contact with environmental materials can be accounted for by the behavior of the latter in solution: activated bentonite releases very large amounts of silicon and sodium into solution while smectite seems to remove silicon from solution.

Selective Leaching Nickel from the Pre-Reduced Limonitic Laterite Ore at Atmospheric Pressure

2012 ◽  
Vol 560-561 ◽  
pp. 494-498
Author(s):  
Yong Feng Chang ◽  
Chuan Lin Fan ◽  
Bin Chuan Li ◽  
Xiu Jing Zhai ◽  
Ting An Zhang
Keyword(s):  
Atmospheric Pressure ◽  
Ph Value ◽  
Test Results ◽  
Selective Leaching ◽  
Nickel Extraction ◽  
Extraction Degree ◽  
Leaching Solution ◽  
Novel Method ◽  
Leaching Condition ◽  
Laterite Ore

In this paper a novel method for selective leaching nickel from pre-reduced laterite ore at atmospheric pressure was reported. The reduced calcine was leached in thin acid liquor to liberate the nickel and iron together firstly. By properly controlling the leaching condition, the leached iron ion could hydrolyze as goethite precipitate and regenerate the acid consumed in the leaching procedure. Finally, the nickel is selectively extracted into the leaching solution. The main factors in the leaching process, such as reduction degree of the laterite ore, acidity of the leaching solution were investigated as influence on the nickel extraction. The test results showed that selectively leaching of nickel could be achieved with an extraction degree up to 90% by reducing most of the iron in the lateritic ore to wuestite and controlling the pH value of the leaching solution below 2.5.

Effect of Precursory Cooling on Falling-Film Rewetting

1975 ◽  
Vol 97 (3) ◽  
pp. 360-365 ◽  
Author(s):  
K. H. Sun ◽  
G. E. Dix ◽  
C. L. Tien
Keyword(s):  
Atmospheric Pressure ◽  
Present Model ◽  
Front Velocity ◽  
Falling Film ◽  
Vapor Mixture ◽  
Thin Slab ◽  
Flow Rates ◽  
Variable Flow ◽  
Order Of Magnitude ◽  
Hot Surface

An analytical model for falling-film wetting of a hot surface has been developed to account for the effect of cooling by droplet-vapor mixture in the region immediately ahead of the wet front. The effect of precursory cooling is characterized by a heat transfer coefficient decaying exponentially from the wet front. Based on the present model, the wet front velocity, as well as the temperature profile along a thin slab, can be calculated. It is demonstrated that the precursory cooling can increase the wet front velocity by an order of magnitude. Existing experimental data with variable flow rates at atmospheric pressure are shown to be successfully correlated by the present model.

scholarly journals Static and Motional Feedthrough Capacitance of Flexural Microresonator

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Wen-Teng Chang
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Network Analyzer ◽  
Reduced Pressure ◽  
Flexural Mode ◽  
Microelectromechanical System ◽  
Order Of Magnitude ◽  
Bode Plots

The present paper evaluates the static and motional feedthrough capacitance of a silicon carbide-based flexural-mode microelectromechanical system resonator. The static feedthrough capacitance was measured by a network analyzer under atmospheric pressure. The motional feedthrough was obtained by introducing various values into the modeling circuit in order to fit the Bode plots measured under reduced pressure. The static feedthrough capacitance was 0.02 pF, whereas the motional feedthrough capacitance of an identical device was about 0.2 pF, which is one order of magnitude larger than the static feedthrough capacitance.

scholarly journals Essay Environment in Indonesian Language Learning

2020 ◽  
Author(s):  
Afifah Tu Sahada
Keyword(s):  
Language Learning ◽  
Everyday Life ◽  
Environmental Material ◽  
Environmental Materials

Environmental materials make it easier for students to understand Indonesian material well, add to students 'insight, and can build students' ecological intelligence. Environmental material is material that is closely related to everyday life. Therefore, with environmental material the teacher can easilyfind relevant examples that make students better understand the material provided, so that it can help teachers imply Indonesian language material.

scholarly journals The Importance of Environmental Materials on Indonesian Language Learning

2020 ◽  
Author(s):  
Ayu Puji Lestari
Keyword(s):  
Language Learning ◽  
Surrounding Environment ◽  
Environmental Material ◽  
Environmental Materials

Based on the results of the author's research above, it can be concluded that environmental material in Indonesian language learning is indeed very important, with environmental material students will increasingly protect and preserve the environment, foster a sensitive attitude to the situation and conditions of the surrounding environment and build honest, disciplined, empathetic characters. and optimistic and religious. This paper aims so that the community and students can protect the environment.

scholarly journals The Importance of Environmental Materials for Learning Indonesian in Schools

2020 ◽  
Author(s):  
Ayu Puji Lestari
Keyword(s):  
Language Learning ◽  
Learning Process ◽  
Surrounding Environment ◽  
Environmental Material ◽  
Environmental Materials

Based on the results of the author's research above, it can be concluded that environmental material in Indonesian language learning in schools is very important. This can be seen from the answers of respondents who stated positively about the importance of environmental materials in Indonesian. With the existence of environmental material will help in the learning process. In addition, students will increasingly protect and preserve their environment, foster a sensitive attitude to the situation and conditions of the surrounding environment and build honest, disciplined, empathetic, and optimistic and religious characters. This paper aims so that the community and students can protect the environment.

A New Method to Measure Prandtl Number and Thermal Conductivity of Fluids

1957 ◽  
Vol 24 (1) ◽  
pp. 25-28
Author(s):  
E. R. G. Eckert ◽  
T. F. Irvine
Keyword(s):  
Thermal Conductivity ◽  
Boundary Layer ◽  
Prandtl Number ◽  
High Velocity ◽  
Atmospheric Pressure ◽  
New Method ◽  
Test Results ◽  
Test Setup ◽  
Velocity Boundary Layer ◽  
Layer Flow

Abstract A new method is described by which the Prandtl number and indirectly the thermal conductivity of fluids can be measured. The method is based on the fact that a well-established, unique relation exists between the Prandtl number and the recovery factor for laminar high-velocity boundary-layer flow. The test setup is described which has been devised for such measurements, and test results are presented for air at atmospheric pressure and temperatures between 60 and 350 F.

The Use of Organic Coatings to Promote Dropwise Condensation of Steam

1987 ◽  
Vol 109 (3) ◽  
pp. 768-774 ◽  
Author(s):  
K. M. Holden ◽  
A. S. Wanniarachchi ◽  
P. J. Marto ◽  
D. H. Boone ◽  
J. W. Rose
Keyword(s):  
Heat Transfer ◽  
Atmospheric Pressure ◽  
Polymer Coatings ◽  
Organic Coatings ◽  
Major Constituent ◽  
Dropwise Condensation ◽  
Test Results ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Sustained Performance

Fourteen polymer coatings were evaluated for their ability to promote and sustain dropwise condensation of steam. Nine of the coatings employed a fluoropolymer as a major constituent; four employed hydrocarbons and one a silicone. Each coating was applied to 25-mm-square by approximately 1-mm-thick metal substrates of brass, copper, copper–nickel, and titanium. While exposed to steam at atmospheric pressure, each coating was visually evaluated for its ability to promote dropwise condensation. Observations were also conducted over a period of 22,000 hr. Hardness and adhesion tests were performed on selected specimens. On the basis of sustained performance, six coatings were selected for application to the outside of 19-mm-dia copper tubes in order to perform a heat transfer evaluation. These tubes were mounted horizontally in a separate apparatus through which steam flowed vertically downward. Steam-side heat transfer coefficients were inferred from overall measurements. Test results indicate that the steam-side heat transfer coefficient can be increased by a factor of five to eight through the use of polymer coatings to promote dropwise condensation.

The Transonic Flow Through a Plane Turbine Cascade as Measured in Four European Wind Tunnels

1986 ◽  
Vol 108 (2) ◽  
pp. 277-284 ◽  
Author(s):  
R. Kiock ◽  
F. Lehthaus ◽  
N. C. Baines ◽  
C. H. Sieverding
Keyword(s):  
Transonic Flow ◽  
High Speed ◽  
Turbine Rotor ◽  
Wind Tunnels ◽  
Test Results ◽  
Turbine Rotor Blade ◽  
Pressure Distributions ◽  
Order Of Magnitude ◽  
Blade Section ◽  
Flow Through

Reliable cascade data are esssential to the development of high-speed turbomachinery, but it has long been suspected that the tunnel environment influences the test results. This has now been investigated by testing one plane gas turbine rotor blade section in four European wind tunnels of different test sections and instrumentation. The Reynolds number of the transonic flow tests was Re2 = 8 × 105 based on exit flow conditions. The turbulence was not increased artificially. A comparison of results from blade pressure distributions and wake traverse measurements reveals the order of magnitude of tunnel effects.

Experimental Research on Shear Strength of Recycled Concrete Block Masonry

2011 ◽  
Vol 374-377 ◽  
pp. 1623-1626
Author(s):  
Feng Jian Zhang ◽  
Guo Liang Bai ◽  
Zong Gang Quan ◽  
Long Pan
Keyword(s):  
Shear Strength ◽  
Concrete Block ◽  
Recycled Concrete ◽  
Wall Material ◽  
Test Results ◽  
Coarse Aggregates ◽  
Shear Property ◽  
Fine Aggregates ◽  
Environmental Material ◽  
Hollow Block

Recycled concrete hollow blocks are made with recycled fine aggregates and recycled coarse aggregates, so recycled block is a kind of green environmental material and can be used for masonry structure. Shear property is one main mechanical property of recycled concrete hollow block masonry. From the shear test of masonry, the shear strength has been researched. At the same time the rule calculated results and test results are compared and analyzed, conclude the design value of shear strength in this paper. The test results show that recycled concrete block masonry has better shear strength, so it can be used for wall material.

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