scholarly journals Scour Protection Effects of a Geotextile Mattress with Floating Plate on a Pipeline

2020 ◽  
Vol 12 (8) ◽  
pp. 3482
Author(s):  
Yehui Zhu ◽  
Liquan Xie ◽  
Tsung-Chow Su
Keyword(s):  
Hydraulic Gradient ◽  
Local Scour ◽  
Test Results ◽  
Plate Height ◽  
Floating Plate ◽  
Oil Transportation ◽  
Parametric Effects ◽  
Opening Ratio ◽  
Series Of Experiments ◽  
Scour Protection

Underwater pipelines are vital to the oil industry. Extending the service life of these pipelines is a key issue in improving the sustainability of oil transportation. A geotextile mattress with floating plate (GMFP) is a novel and sustainable countermeasure for scour and erosion control and is herein introduced to protect a partially buried pipeline from local scour in steady currents. A series of experiments was designed to verify the protection capabilities of the GMFP and investigate its parametric effects on protection. The average seepage hydraulic gradient under the pipeline was adopted to depict the protection effects of the GMFP, and was calculated with the pore pressure readings under the pipeline. The test results show that the GMFP is capable of protecting a pipeline from the onset of local scour in a unidirectional current. The average seepage hydraulic gradient below the pipeline decreases remarkably after a GMFP is installed. The average hydraulic gradient shows a descending trend with increased sloping angle α when 0.64 < sinα < 0.77. The hydraulic gradient hits a nadir at sinα = 0.77 and climbs with the increasing sloping angle when sinα > 0.82. The hydraulic gradient ascends when the bottom opening ratio δ increases from 0.167 to 0.231, due to the decreased intensity of the bottom vortex. The hydraulic gradient drops with a rising plate height, except for a fluctuation at Hp = 0.12 m. An approximate negative correlation is found between the obstruction height of the floating plate and the average hydraulic gradient under the pipeline. This could be partially attributed to the extension and amplification of the bottom vortex on the leeside of the pipeline due to the increased plate obstruction height.

scholarly journals Enhancing scour protection in river bends: a novel slotted bank-attached vane

2020 ◽  
Vol 20 (6) ◽  
pp. 2175-2184
Author(s):  
Mohamad Azizipour ◽  
Farshid Amirsalari Meymani ◽  
Mohammad Mahmoodian Shooshtari
Keyword(s):  
Effective Area ◽  
Local Scour ◽  
Flume Experiments ◽  
Rectangular Slot ◽  
Outer Bank ◽  
Scour Hole ◽  
Submerged Vane ◽  
River Bends ◽  
Scour Protection ◽  
Control Erosion

Abstract One of the most effective approaches for bank control erosion is using bank-attached vanes. In spite of the superiority of the bank-attached vanes to spur dikes, the vanes' tips are still vulnerable to local scour caused by flow–structure interaction. In this study, slotted bank-attached vanes are proposed to reduce local scour at the tip of the triangular submerged vane. For this, a rectangular slot is created parallel to the chord of the vane with an area of ten percent of the effective area of the vane surface. Two types of conventional vanes and slotted vanes were installed at different angles of attack of 23, 30, 40 and 60 degrees in an arch flume. Experiments were carried out in clear water conditions with different flow regimes with Froude numbers of Fr = 0.287, 0.304 and 0.322. The results show that the slotted vane outperforms the conventional vane by reducing maximum scour depth by about 70, 20, 17 and 54 percent for different angles of attack of 23, 30, 40 and 60 degrees, respectively. The proposed slotted vane also resulted in reduction of scour hole volume around the vane and formed the scour hole away from the outer bank.

scholarly journals Experimental Investigation of Local Scour Protection for Cylindrical Bridge Piers Using Anti-Scour Collars

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1515 ◽  
Author(s):  
Shunyi Wang ◽  
Kai Wei ◽  
Zhonghui Shen ◽  
Qiqi Xiang
Keyword(s):  
Protective Effect ◽  
Local Scour ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Experimental Program ◽  
Design Parameters ◽  
External Diameter ◽  
River Sand ◽  
Bed Scour ◽  
Scour Protection

Local scour of bridge piers is one of the main threats responsible for bridge damage. Adopting scour countermeasures to protect bridge foundations from scour has become an important issue for the design and maintenance of bridges located in erodible sediment beds. This paper focuses on the protective effect of one active countermeasure named an “anti-scour collar” on local scour around the commonly used cylindrical bridge pier. A cylindrical pier model was set up in a current flume. River sand with a median particle size of 0.324 mm was selected and used as the sediment in the basin. A live-bed scour experimental program was carried out to study the protective effect of an anti-scour collar by comparing the local scour at a cylindrical bridge pier model with and without collar. The effects of three design parameters including collar installation height, collar external diameter and collar protection range, on the scour depth and scour development were investigated parametrically. According to the experimental results, it can be concluded that: the application of an anti-scour collar alleviates the local scour at the pier effectively; and the protection effect decreases with an increase in the collar installation height, but increases with an increase in the collar external diameter and the protection range. Design suggestions for improving the scour protective effect of the anti-scour collar are summarized and of great practical guiding significance to the development of anti-scour collars for bridge piers.

Measuring Sterilizing Values In Containers of Food Using Thermocouples and Biological Indicator Units1,2

1980 ◽  
Vol 43 (2) ◽  
pp. 119-123 ◽  
Author(s):  
I. J. PFLUG ◽  
G. SMITH ◽  
R. HOLCOMB ◽  
R. BLANCHETT
Keyword(s):  
Coefficient Of Variation ◽  
Biological Indicator ◽  
Experimental Series ◽  
Test Results ◽  
Heat Penetration ◽  
Series Of Experiments ◽  
The Mean ◽  
Penetration Data

Three series of experiments were carried out. Each experiment consisted of six or seven tests where four or five containers were fitted with thermocouples and five were fitted with biological indicator units (BIU). The sterilization value (F0) delivered to cans of peas in brine was calculated from heat penetration data. The heat penetration data were analyzed for test-to-test reproducibility within each experimental series. Sterilization values for all tests were calculated from the BIU test results. The sterilizing values F0 (PHY) determined from physical (PHY) heat penetration data were compared with sterilizing values F0 (BIO) determined using the BIUs, both on the basis of accuracy and variability. The mean F0 (PHY) - F0 (BIO) was + 1.2 min. The mean coefficient of variation of the F0 (PHY) was 0.03 and the F (BIO) was 0.06.

scholarly journals Experimental Work Conducted on MgO Characterization and Hydration

2008 ◽  
Vol 1124 ◽  
Author(s):  
Haoran Deng ◽  
Yongliang Xiong ◽  
Martin Nemer ◽  
Shelly Johnsen
Keyword(s):  
Control Agent ◽  
Department Of Energy ◽  
Fractional Factorial ◽  
Test Results ◽  
Waste Isolation Pilot Plant ◽  
Large Particles ◽  
Series Of Experiments ◽  
Engineered Barriers ◽  
And Diffusion ◽  
Transuranic Waste

AbstractMagnesium oxide (MgO) is the only engineered barrier certified by the EPA for emplacement in the Waste Isolation Pilot Plant (WIPP), a U.S. Department of Energy repository for transuranic waste. MgO will reduce actinide solubilities by sequestering CO2 generated by the biodegradation of cellulosic, plastic, and rubber materials. Demonstration of the effectiveness of MgO is essential to meet the U.S Environmental Protection Agency's requirement for multiple natural and engineered barriers. In the past, a series of experiments was conducted at Sandia National Laboratories to verify the efficacy of Premier Chemicals LLC (Premier) MgO as a chemical-control agent in the WIPP. Since December 2004, Premier MgO is no longer available for emplacement in the WIPP. Martin Marietta Magnesia Specialties LLC is the new MgO supplier. MgO characterization, including chemical, mineralogic, and reactivity analysis, has been performed to address uncertainties concerning the amount of reactive constituents in Martin Marietta MgO. Characterization results of Premier MgO will be reported for comparison. Particle size, solid-to-liquid ratio, and stir speed could affect the rate of carbonation of MgO slurries. Thus, it's reasonable to hypothesize that these factors will also affect the rate of hydration. Accelerated MgO hydration experiments were carried out at two or three levels for each of the above factors in deionized water at 70 °C. The Minitab statistical software package was used to design a fractional-factorial experimental matrix and analyze the test results. We also fitted the accelerated inundated hydration data to four different kinetic models and calculated the hydration rates. As a result of this study we have determined that different mechanisms may be important for different particle sizes, surface control for large particles and diffusion for small particles.

scholarly journals Local scour protection using geocell for downstream of spillway

2021 ◽  
Vol 9 (3B) ◽  
Author(s):  
Enes GUL ◽  
◽  
Talha SARICI ◽  
Omerul Faruk DURSUN ◽  
◽  
...  
Keyword(s):  
Local Scour ◽  
Hydraulic Structures ◽  
Scour Depth ◽  
Percentage Reduction ◽  
Confinement System ◽  
Bed Materials ◽  
Scour Protection

Local scour is an important problem for hydraulic structures. The local scour in the downstream of dams causes problems such as the damage of the dam body stabilization, erosion of the slopes, and the submergence of the turbines. There are many studies investigating the local scour prediction of the downstream of the hydraulic structures, but in recent years, these studies have been replaced by studies of local scour reduction. The new idea of confining the bed materials using the geocell is becoming a popular solution. This solution can be especially used for the reinforcement of the soils. In this study, the preventability of the local scour downstream of chute channel by cellular confinement system, also known as geocell, was investigated. As a result, in case of using geocell, percentage reduction of the maximum scour depth up to 40.63% was observed.

scholarly journals Some of test results of the “Aldofix” in fixing the phytoplankton on the example of eggs of walleye pollock Theragra chalcogramma

2020 ◽  
Vol 1 (56) ◽  
pp. 120-126
Author(s):  
D. Ya. Saushkina ◽  
A. V. Vinogradskaya
Keyword(s):  
Walleye Pollock ◽  
Theragra Chalcogramma ◽  
Test Results ◽  
External View ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Series Of Experiments ◽  
Egg Diameter

Data about new conservant “Aldofix” to fix ichthyoplankton are demonstrated. Series of experiments on the conservation of ichthyoplankton and eggs of walleye pollock were carried out with the use of “Aldofix” and its modernized solutions. External view, including color of the eggs, as a result of fixing in different solutions was described, and difference in the egg diameter was noted in case of fixing in formalin and “Aldofix”. It is concluded, that “Aldofix” (example № 1) was the most convinient fixing solution to preserve ichthyoplankton.

Effects of Dust Composition on Particle Deposition in an Effusion Cooling Geometry

2019 ◽  
Author(s):  
Evan D. Crowe ◽  
Jeffrey P. Bons
Keyword(s):  
Mass Flow ◽  
Particle Deposition ◽  
Volume Fraction ◽  
Weighted Average ◽  
Test Results ◽  
Mass Fractions ◽  
Dust Composition ◽  
Mineral Dusts ◽  
Series Of Experiments ◽  
Effusion Hole

Abstract In this study the effects of dust composition on particle deposition in an effusion cooling geometry were investigated through a series of experiments. Single mineral dusts made from five different minerals, Quartz, Dolomite, Albite, Salt, and Gypsum, were milled to similar size distributions (approx. 0–10μm diameter). These dusts were then used in particle deposition tests on a flat plate effusion hole test article which was heated in a kiln to 1116K and supplied with coolant flow heated to 950K. Percent mass flow reduction per gram and deposit morphology were recorded for each test. Results for the different minerals varied greatly ranging from 7.8% to 160% reduction in mass flow per gram injected, with the albite dust producing the greatest blockage. The different dusts also produced varying shapes of deposits. These five dusts were then combined to form a dust blend with the same mass fractions found in AFRL02, a commercially available test dust, and additional tests were conducted using this dust. Results from the tests using the OSU mixed AFRL02 were compared with an estimated blockage per gram found by taking a weighted average of the blockage per gram for each single mineral dust on a percent volume basis. When tested, the mixed AFRL02 produced a lower blockage per gram than the estimate, indicating that an estimate based on volume fraction alone is not sufficient to predict the deposition of dusts composed of a mixture of minerals.

Stable and Unstable Crack Growth of A508 Class 3 Plates Subjected to Combined Force of Thermal Shock and Tension

1989 ◽  
Vol 111 (3) ◽  
pp. 234-240 ◽  
Author(s):  
G. Yagawa ◽  
Y. Ando ◽  
K. Ishihara ◽  
T. Iwadate ◽  
Y. Tanaka
Keyword(s):  
Thermal Shock ◽  
Nuclear Power ◽  
Power Plants ◽  
Fracture Behavior ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Test Results ◽  
Unstable Crack ◽  
Pressurized Thermal Shock ◽  
Series Of Experiments

An urgent problem for nuclear power plants is to assess the structural integrity of the reactor pressure vessel under pressurized thermal shock. In order to estimate crack behavior under combined force of thermal shock and tension simulating pressurized thermal shock, two series of experiments are demonstrated: one to study the effect of material deterioration due to neutron irradiation on the fracture behavior, and the other to study the effect of system compliance on fracture behavior. The test results are discussed with the three-dimensional elastic-plastic fracture parameters, J and Jˆ integrals.

Structural performance of cavity walls constructed with units containing sawdust and shear connected to the brick veneer

1994 ◽  
Vol 21 (4) ◽  
pp. 576-584
Author(s):  
Ajay Goyal ◽  
M. Shokry Rashwan ◽  
M. A. Hatzinikolas ◽  
S. Zervos
Keyword(s):  
Lightweight Concrete ◽  
Structural Performance ◽  
Test Results ◽  
Lateral Loads ◽  
Burnt Clay ◽  
Concrete Masonry ◽  
Brick Veneer ◽  
Series Of Experiments ◽  
Masonry Units ◽  
Cavity Width

A series of experiments were conducted to investigate the behaviour of walls constructed using newly developed masonry sawdust blocks. Full-scale cavity walls consisting of the new masonry block backup and burnt clay brick veneer, connected together using metal connectors, were tested under lateral loads. The effects of block unit size, height of wall, reinforcement, grout, and cavity width on the behaviour of the wall were studied. The test results showed behaviour similar to that of walls constructed with lightweight concrete masonry units. A summary of the results is presented in this paper. Key words: masonry, cavity wall, shear connector, lateral loading, stiffness, veneer, sawdust block.

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