scholarly journals Reduction of Local Scour Around A Bridge Pier Using Triple Rectangular Plates

2015 ◽  
Vol 10 (Special-Issue1) ◽  
pp. 47-55 ◽  
Author(s):  
Alireza Arabani ◽  
Human Hajikandi
Keyword(s):  
Water Flow ◽  
Flow Direction ◽  
Side Wall ◽  
Local Scour ◽  
Maximum Efficiency ◽  
Rectangular Plates ◽  
Clear Water ◽  
The Third ◽  
Different Depths ◽  
Lateral Plates

The performance of vertical triple plates as a new countermeasure in control of local scour around a cylindrical model pier is studied. Two ones of the plates are attached to the side wall one of the pier at one pier diameter distance, extending toward upstream distance and the third one is located in the middle, attached to the pier nose. All the three plates are parallel to flow direction. Experiments are conducted for five different depths of flow and two different lengths of the lateral plates, namely 8 and 14 cm. all the runs are performed under the clear water flow over uniform sediment. The results showed a maximum efficiency of 76% in scour reduction for 8 cm long side plates and 85% for 14 cm long ones.it is also found that the proposed setup act simultaneously as both the bed armoring and flow altering countermeasure.

scholarly journals Local scour at vertical-wall abutments under clear-water flow conditions

2006 ◽  
Vol 42 (10) ◽  
Author(s):  
Cristina Maria Sena Fael ◽  
Gonzalo Simarro-Grande ◽  
Juan-Pedro Martín-Vide ◽  
António Heleno Cardoso
Keyword(s):  
Water Flow ◽  
Vertical Wall ◽  
Local Scour ◽  
Clear Water ◽  
Flow Conditions

Clear-Water Local Scour around Pile Groups in Shallow-Water Flow

2012 ◽  
Vol 138 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Ata Amini ◽  
Bruce W. Melville ◽  
Thamer M. Ali ◽  
Abdul H. Ghazali
Keyword(s):  
Shallow Water ◽  
Water Flow ◽  
Local Scour ◽  
Clear Water ◽  
Pile Groups ◽  
Shallow Water Flow

scholarly journals Modeling Local Scour around a Cylindrical Pier with Circular Collar with Tilt Angles (Counterclockwise around the Direction of the Channel Cross-Section) in Clear-Water

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3281
Author(s):  
Hongliang Qi ◽  
Weiping Tian ◽  
Haochi Zhang
Keyword(s):  
Cross Section ◽  
Tilt Angle ◽  
Early Stage ◽  
Flow Direction ◽  
Local Scour ◽  
Channel Cross Section ◽  
Scour Depth ◽  
Clear Water ◽  
Eddy Simulation ◽  
Scouring Depth

This research explores how a circular collar with a tilt angle (counterclockwise around the direction of the channel cross-section) could affect the local scour depth around a single cylindrical pier in clear-water based on Large Eddy Simulation (LES) in six cases. The results show that a horizontal circular collar is the best for reducing the local scour depth. With the increases of the tilt angle, the effect on reducing the local scour depth decreases gradually and is even counterproductive at the scour equilibrium. At the early stage of scouring, cases with circular collars show obvious scouring depth reductions. The smaller the tilt angle is, the better and longer-lasting the protection that the circular collar can provide. When the tilt angle is smaller than 5°, the location of the maximum local scouring is around 90–115° (the angle is measured clockwise from the flow direction) on both sides of the pier. When the tilt angle is greater than 5°, the depth of local scouring in the range around −115° to 115° is close to the maximum local scouring depth. Significantly larger areas reach the maximum scouring depth when the tilt angle increases. Compared to Case 1 (the pier without a circular collar), in the cases with a circular collar, the topographies downwards the pier in 1.0D (D is the diameter of the bridge pier) are changed to siltation from scouring. The topography downwards the pier changes from scouring to siltation with the increase of the tilt angle, and the shape of siltation changes from a long-narrow rectangle to an equilateral triangle. This study may provide valuable insights into the protection of the local scour of the pier.

Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system

2011 ◽  
Vol 2 (1) ◽  
pp. 13-17
Author(s):  
I. David ◽  
M. Visescu
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Geothermal Energy ◽  
Flow Direction ◽  
Energy Resource ◽  
Hot Water ◽  
Injection Well ◽  
Production Well ◽  
Ground Water Flow ◽  
The Earth

Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

scholarly journals The effect of feeding high levels of low-quality proteins to growing chickens

1975 ◽  
Vol 34 (3) ◽  
pp. 363-373 ◽  
Author(s):  
E. Wetnli ◽  
T. R. Morris ◽  
T. P. Shresta
Keyword(s):  
Growth Rate ◽  
Amino Acid ◽  
Dietary Protein ◽  
Soya Bean ◽  
Maximum Efficiency ◽  
Food Utilization ◽  
The Third ◽  
Bean Meal ◽  
Groundnut Meal ◽  
Soya Bean Meal

1. Three growth trials were done using male broiler chicks. In the first two trials, groundnut meal was used, with and without supplementary methionine and lysine. In the third trial, soya-bean meal was used with and without supplementary methionine. Protein levels ranged in the first trial from 120 to 420 g/kg diet and in the third trial from 120 to 300 g/kg diet. Thus the assumed minimal amino acid requirements of the chick were supplied by high levels of low-quality dietary protein.2. Diets based on cereals and groundnut meal did not support maximum live-weight gain or maximum efficiency of food utilization at any level of dietary protein. When the principal deficiencies of lysine and methionine were corrected, this protein mixture was capable of supporting the same growth rate as a control diet of cereals and herring meal.3. Diets based on maize and soya-bean meal did not support quite the same growth rate as similar diets supplemented with methionine, even though the protein level in the unsupplemented diets was sufficient to meet the assumed methionine requirements.4. These results are interpreted as examples of amino acid imbalance in diets composed of familiar feeding-stuffs. It is concluded that one cannot assume that the poor quality of a protein source can always be offset by increasing the concentration of dietary protein.

Behavior and Distribution of Nonylphenol Ethoxylates and their Metabolites in Sediments of Nansi Lake, China

2011 ◽  
Vol 356-360 ◽  
pp. 1733-1738
Author(s):  
Fang He ◽  
Aya Obara ◽  
Shi Long Wang ◽  
Li Guo Wang
Keyword(s):  
Water Flow ◽  
Flow Direction ◽  
Sediment Cores ◽  
Sewage Treatment ◽  
Vertical Direction ◽  
Total Content ◽  
Horizontal Distribution ◽  
Nansi Lake ◽  
Increasing Trend ◽  
Vertical And Horizontal Distribution

The vertical and horizontal distribution of NPEOn and their metabolites of NP and NPEnC in the Upper Nansi Lake, North China were investigated using LC-MS and LC-MS/MS methods, sampling at three sites (St.1, St.2 and St.3) along the water flow direction. The total content of NPEOn (n=1–15) bound onto the sediment of this lake changed in the range of 60.7–631.5 μg/kg-dry with the horizontal flow direction and the vertical direction of the sediment cores with sediment thickness up to 35 cm. Compared to the presence levels of all detected NPEOn species, the content of NP was much higher, falling in 26.5–1,998.4 μg/kg-dry. A general increasing trend of the NP content along the water flow direction of this lake was revealed. NPEnC showed a roughly increasing trend from the upstream to the downstream, with the total concentrations being obviously lower than NPEOn and NP and falling in 2.13–23.1 μg/kg-dry. The short chain NPEOn dominant in NPEO mixtures in these sedimentary cores indicated that this lake received some effluents from STPs, and the sewage treatment ratio is relatively low in this area. Furthermore, the computed magnitudes of NPEO 1-2/NPEO1-15, NP/NPEO 1-15 and NPEC 1-10/NPEO 1-15 suggested that the non-oxidative hydrolytic transformation seemed to be a major process occurring within the sediment phase of Nansi Lake, while the oxidative hydrolytic transformation pathway was probably less involved.

scholarly journals Performance of supermarkets in Santa Catarina: an analysis of small and medium-sized units

2020 ◽  
Vol 27 (4) ◽  
Author(s):  
Julio Cesar Araujo Silva Junior ◽  
Douglas Nodari ◽  
Mariana de Oliveira Cavalheiro ◽  
Fernanda Gomes Victor
Keyword(s):  
Data Envelopment Analysis ◽  
Third Sector ◽  
Individual Performance ◽  
Maximum Efficiency ◽  
Data Envelopment ◽  
Santa Catarina ◽  
The Third ◽  
Strong Competition ◽  
Using Data ◽  
Relevant Finding

Abstract: The retail supermarket sector is one of the most important in the third sector. Besides being one of that most generates direct and indirect jobs, it is one of the first to capture changes in consumer behavior. Given the strong competition and constant evolution of the sector, it is necessary to improve techniques for individual performance measurement of the networks and the construction of parameters of relative comparison between the units. The aim of this article is to analyze the efficiency of a 31 supermarkets sample in Santa Catarina, using Data Envelopment Analysis (DEA). The variables used in the investigation were gross sales, the number of employees, sales area and number of checkout's in the period of 2014 and 2015. The results pointed out a low percentage of units at maximum efficiency for the two periods analyzed. Another relevant finding was that the variables that presented a mismatch to reach the maximum efficiency of the units was the “Sales area (m2)” and “number of employees“, suggesting the existence of idle structure capacity.

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