BIOLOGICAL EFFECTS OF LOW-PRESSURE SEAWATER FLUSHING OF OILED SEDIMENTS

1987 ◽  
Vol 1987 (1) ◽  
pp. 439-443
Author(s):  
S. Howard ◽  
D. I. Little
Keyword(s):  
Shear Strength ◽  
Surface Layer ◽  
Water Table ◽  
Biological Effects ◽  
Low Pressure ◽  
Fuel Oil ◽  
Arenicola Marina ◽  
Intertidal Sand ◽  
Low Shear

ABSTRACT The objectives of this study were to assess the field effectiveness and biological effects of low-pressure saltwater flushing of a thin (<4 mm) oil layer applied to a very fine intertidal sand. On average approximately 85 percent of the applied medium fuel oil mousse was found to be recoverable. Hydrocarbon analyses indicated negligible oil incorporation into flushed plots. The technique is believed to have been effective partly because the water table was successfully raised (by up to 20 cm), and also because the surface 3 to 4 cm was sufficiently disturbed to liberate oil that had penetrated the surface layer during the 2 hours between oil application and flushing. Counts of Arenicola marina casts in “oiled” plots were significantly lower (P = 0.02) than in the “oiled and then flushed” plots. The technique is likely to work with viscous oils deposited in 10 mm thick Strandlines on accessible sloping shores, where the sediment is greater than 4 cm thick and reasonably firm. The technique is likely to be unsuccessful on very coarse sands and gravels, fluid muds, and low shear strength sands, because of erosion and mixing of sediments and oil.

scholarly journals The Hybrid Process of Low-Pressure Carburizing and Metallization (Cr + LPC, Al + LPC) of 17CrNiMo7-6 and 10NiCrMo13-5 Steels

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 567
Author(s):  
Paulina Kowalczyk ◽  
Konrad Dybowski ◽  
Bartłomiej Januszewicz ◽  
Radomir Atraszkiewicz ◽  
Marcin Makówka
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Physicochemical Properties ◽  
Surface Treatment ◽  
Retained Austenite ◽  
Treatment Process ◽  
Active Surface ◽  
Low Pressure ◽  
Low Alloy Steel ◽  
Chromium Plating

This paper presents the concept of modification of physicochemical properties of steels by simultaneous diffusion saturation with carbon and chromium or aluminum. The application of a hybrid surface treatment process consisting of a combination of aluminizing and low-pressure carburizing (Al + LPC) resulted in a reduction in the amount of retained austenite in the surface layer of the steel. While the use of chromium plating and low-pressure carburizing (Cr + LPC) induced an improvement in the corrosion resistance of the carburized steels. It is of particular importance in case of vacuum processes after the application of which the active surface corrodes easily, as well as in case of carburizing of low-alloy steel with nickel, where an increased content of retained austenite in the surface layer is found after carburizing.

Dynamic bending of plates with low shear strength

1972 ◽  
Vol 4 (4-6) ◽  
pp. 544-549
Author(s):  
B. L. Pelekh ◽  
G. A. Teters
Keyword(s):  
Shear Strength ◽  
Dynamic Bending ◽  
Low Shear

Flexure of beams with low shear strength on an elastic foundation

1971 ◽  
Vol 3 (5) ◽  
pp. 582-585 ◽  
Author(s):  
Yu. M. Tarnopol'skii ◽  
A. V. Roze ◽  
R. P. Shlitsa
Keyword(s):  
Shear Strength ◽  
Elastic Foundation ◽  
Low Shear

The Modification of Carbon Included Polyethylene Surface by Plasma Treatment for Metallizing Using a Low Pressure RF Discharge Plasma

2005 ◽  
Vol 8 (1) ◽  
Author(s):  
Jeou-Long Lee ◽  
Chung-Ming Liu ◽  
Kuen Ting ◽  
Wei-Kung Cheng ◽  
Takayoshi Tsuchida ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Layer ◽  
Discharge Plasma ◽  
Treatment Time ◽  
Low Pressure ◽  
Rf Discharge ◽  
Nickel Layer ◽  
Good Adhesion ◽  
Polyethylene Surface

AbstractSurface modification of the carbon included polyethylene (semi-conductive PE) surface for metallizing using a low pressure RF discharge plasma has been carried out. The contact angle was used as a measure of the wettability of the PE surface. The roughness and the chemical bondings in PE surface layer were analized by DFM and XPS, respectively. Typical results show that the contact angle decreases from approximately 94° to below 10° after several minutes' treatment and recovers to a saturation value when it was put open to the air after treatment. The saturation value of the contact angle is smaller as the gas pressure for treatment is higher and the treatment time is longer but all are below approximately 60° which is still smaller than that of untreated. DFM and XPS results show that the surface roughness and the bondings C-O and C=O in the PE surface layer also increase with increasing the treatment time and seem to be responsible for improving the hydrophilic property of PE. After pretreatment process, nickel was coated on the PE sheet by electrodeposition method and a good adhesion between the nickel layer and the PE surface compared with that of untreated was obtained.

Application of the Rotating Water Table to Nozzle Wake Excitation in Low Pressure Turbines

1985 ◽  
Author(s):  
Shun Chen
Keyword(s):  
Water Table ◽  
Low Pressure ◽  
Test Facility ◽  
Test Results ◽  
Unsteady Forces ◽  
Low Pressure Turbine ◽  
Rotating Blade ◽  
Stator Vane ◽  
Two Dimensional Flow ◽  
Hydraulic Analogy

The hydraulic analogy was employed in a rotating water table for simulating the compressible two dimensional flow in a low pressure turbine stage. Both steady and unsteady forces were measured directly on a rotating blade in a blade row rotating concentrically with a row of stator vanes. With proper modeling of the simulation, it is shown that the rotating water table can yield results that agree favorably with the analytical predictions and turbine test results. Using this test facility, the effects of axial spacing between rotor and stator rows on the nozzle wake excitation have been investigated for two different stator vane profiles. The water table test results correlate qualitatively with the turbine test data. The cancellation of nozzle passing frequency excitation by off-setting nozzle pitch was demonstrated in the water table and the results compared with both the analytical predictions and the laboratory turbine test results.

scholarly journals Daytime preservation of surface-hoar crystals

1998 ◽  
Vol 26 ◽  
pp. 22-26 ◽  
Author(s):  
Akihiro Hachikubo ◽  
Eizi Akitaya
Keyword(s):  
Shear Strength ◽  
Surface Layer ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Surface Temperature ◽  
Snow Surface ◽  
Previous Night ◽  
Snow Surface Temperature ◽  
Transfer Method

Surface hoar growing for several clear and humid days were observed. During daytime, air and snow-surface temperature increased and relative humidity decreased, hence evaporation (sublimation) occurred at the snow surface. The amount of evaporation calculated using a bulk-transfer method suggests that the surface-hoar crystals which grew during the previous night should have disappeared but they were observed to survive on the snow surface even during the daytime. During the following night, new surface-hoar crystals formed on top of the older ones and grew even larger. This result indicates that, although the surface-hoar crystals evaporated into the air during the daytime, snow grains beneath the surface were warmed by solar radiation and evaporated to the air. They may partially condense into the surface-hoar crystals and make up for the reduction in size. Depth-hoar crystals formed beneath the snow surface for several days and the surface layer, composed of both types of hoar crystal, showed a very weak shear strength.

scholarly journals Application of FRP Bolts in Monitoring the Internal Force of the Rocks Surrounding a Mine-Shield Tunnel

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2763 ◽  
Author(s):  
Zhen Liu ◽  
Cuiying Zhou ◽  
Yiqi Lu ◽  
Xu Yang ◽  
Yanhao Liang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Internal Force ◽  
Shield Tunnel ◽  
Corrosive Environment ◽  
High Tensile Strength ◽  
Technological Support ◽  
Remote Monitoring System ◽  
Initial Support ◽  
Low Shear

Monitoring the internal force of the rocks surrounding a mine-shield tunnel for the initial support of a mine-shield tunnel, in complex geological and hydrological environments, requires bolts with specific features such as high tensile strength, low shear strength, good insulation and resistance to corrosion. As such, internal force monitoring has become an important issue in safety monitoring for such tunneling projects. In this paper, the adaptability of a mine-shield tunnel project in a corrosive environment is investigated. A fiberglass reinforced plastic (FRP) bolt with high tensile strength, low shear strength, resistance to fatigue, non-conductivity and resistance to corrosion is used as a probe in tandem with an anchor-head dynamometer to monitor the internal force of the rocks surrounding a mine-shield tunnel for initial support. Additionally, solar energy collection technology is introduced to create a remote monitoring system. Using a 2.5 km long railway tunnel located in the northeast of the Pearl River Delta of China as a case study, the present study shows that, compared with a conventional steel bolt, the FRP bolt has advantages, such as avoidance of the risks associated with the shield machine, insulation and resistance to corrosion. As a probe, the response of the FRP bolt to events such as a blasting vibration and a construction disturbance that results in internal changes in the surrounding rock demonstrates a clear pattern that is appropriate for monitoring the internal force of the rocks surrounding a mine-shield tunnel in a corrosive environment. FRP bolt-based monitoring not only provides new technological support for controlling the risk involved in the initial support of a mine-shield tunnel but can also be widely deployed in projects with special requirements for disassembly, conductivity and corrosion.

The effect of soil strength on germination and emergence of wheat (Triticum aestivum L.). I. Low shear strength conditions

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 577 ◽  
Author(s):  
N Collis-George ◽  
P Yoganathan
Keyword(s):  
Triticum Aestivum ◽  
Shear Strength ◽  
Root Elongation ◽  
Experimental Studies ◽  
Fine Sand ◽  
Triticum Aestivum L ◽  
Initial Soil ◽  
Soil Shear Strength ◽  
Coleoptile Elongation ◽  
Low Shear

Experimental studies of the germination and emergence of wheat as affected by soil shear strength are reported. A fine sand under saturated conditions was used as the seed bed and the shear strength of the seed bed was increased to 10 kPa (0.1 bar) by externally applied loads. From the results it is concluded that the initial soil shear strength in this range has little effect on germination. However, coleoptile growth and root elongation are markedly reduced in the range 0-2.2 kPa such that total emergence is reduced to 7% at 9.3 kPa in this fine sand. The results clearly show that coleoptile elongation is more affected than root elongation by the same mechanical stress. Roots are found to be thicker and coleoptile thinner under increasing soil shear strength conditions.

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