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1
He, Na, Liuqing Yang, Linjuan Xu i Wanjie Zhao. "Experimental Study on the Scouring Rate of Cohesive Soil in the Lower Yellow River". Coatings 12, nr 3 (21.03.2022): 418. http://dx.doi.org/10.3390/coatings12030418.
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The different soil anti scourability in the lower reaches of the Yellow River leads to different scouring and retreating speeds, which has a great influence on river regime evolution. Through the incipient motion scouring test of cemented cohesive soil in the lower reaches of the Yellow River, the physical phenomena of the incipient motion of cohesive soil were expounded, the scouring rate of cohesive soil was calculated, and the relationship between the scouring rate and its influencing factors was established. The results show that when the moisture content of cohesive soil is 43%~61%, the scouring rate is about 0.001~0.03 kg/(m2·s). The scouring rate of cohesive soil with the same particle size varies with the flow shear stress under different deposition duration conditions. Under the same flow rate, the scouring rate of cohesive soil increases with the increase of water content, showing an exponential relationship of increment. Under the same shear stress condition, the scouring rate decreases with the increase of dry density, while the exponential relationship between dry density and scouring rate is not clear when the shear stress is small. With the increase of shear stress, there is an obvious exponential relationship between dry density and scouring rate. Finally, the relationship between the scouring rate and relative residual shear stress was established, and the scouring rate formula suitable for cohesive extremely fine sediment was fitted. The formula can better estimate the scouring rate of the riverbank composed of very fine cohesive sediment and provide support for predicting the scouring and retreating rate of riverbanks in natural rivers.
2
Czaplicki, Zdzisław, Edyta Matyjas-Zgondek i Stanisław Strzelecki. "Scouring of Sheep Wool Using an Acoustic Ultrasound Wave". Fibres and Textiles in Eastern Europe 29, nr 6(150) (31.12.2021): 44–48. http://dx.doi.org/10.5604/01.3001.0015.2721.
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The paper describes a method of scouring sheep wool using ultrasound.The inspiration to start work on the use of ultrasound in the process of scouring sheep wool was positive results that had already been achieved for alpaca wool. Due to the fact that sheep wool has many more impurites than alpaca wool, the scouring process is divided into two stages. The first involves the removal of faeces from the wool, which may be up to about 35% of the impurities of sheep wool, while the second stage involves the scouring cycle, wherein the remaining impurities are removed. The ultrasonic scouring process uses domestic merino wool heavily clad, particularly, by faeces. In this study, detergent solutions, alkali soap and sodium carbonate were used. The scouring of wool was carried out with a special apparatus equipped with an ultrasonic generator, at a frequency of 40 kHz. To determine the optimal conditions for scouring sheep wool that could affect the amount of impurities removed, the following parameters were examined: the effect of the scouring time, the concentration of detergents, and the scouring bath ratio. The study resulted in achieving optimal scouring parameters that ensured a satisfactory level of the removal of wool impurities.
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Schofield, J. "Standard Scouring Systems." Journal of the Society of Dyers and Colourists 37, nr 12 (22.10.2008): 298–301. http://dx.doi.org/10.1111/j.1478-4408.1921.tb01108.x.
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Anab-Atulomah, Chidiebere, i Ejikeme Nwachukwu. "Bio-Scouring of Cotton using Protease and Pectinase from Bacillus subtilis Isolated from Market Waste". Path of Science 7, nr 7 (31.07.2021): 3001–6. http://dx.doi.org/10.22178/pos.72-3.
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The bio-scouring of cotton using protease and pectinase produced from Bacillus subtilis was investigated. Protease and pectinase were produced from Bacillus subtilis in a liquid medium using the submerged fermentation technique. Both enzymes were purified, and their scouring potential was tested on raw cotton fabrics. Pectinase was more effective than protease under optimised conditions. The optimum scouring temperature for both enzymes was between 40 °C and 50 °C, with pectinase bio-scoured fabric showing 15.5% weight loss while protease bio-scoured fabric had 14.3% weight loss. The optimum pH for pectinase scouring was pH 9 with 14.8% weight loss in the fabric, while the optimum pH for protease scoured fabric was pH 7 with 12.3% weight loss in fabric. After 120 minutes of bio-scouring, maximum weight loss was recorded for both pectinase and protease treated fabrics. The application of protease and pectinase for cotton fabric scouring revealed that they could be used as bio-scouring agents to treat textile materials.
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Ghaderi, Amir, Rasoul Daneshfaraz, Mohammadamin Torabi, John Abraham i Hazi Mohammad Azamathulla. "Experimental investigation on effective scouring parameters downstream from stepped spillways". Water Supply 20, nr 5 (29.05.2020): 1988–98. http://dx.doi.org/10.2166/ws.2020.113.
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Abstract Experimental tests were carried out to investigate the effective scouring parameters downstream from stepped spillways with different flow rates and step sizes. The results indicated that the flow regime plays an important role in scour-hole dimensions such that the minimum scouring depth happens in the nappe flow regime. Moreover, step size and tailwater depth are essential parameters for maximum scouring depth. Increasing tailwater depth from 6.31 cm to 8.54 cm and then to 11.82 cm decreases the scouring depth by 18.56% and 11.42%, respectively. These alterations also decrease the scouring length by 31.43% and 16.55%, respectively. By increasing the flow rate, the particle Froude number will increase, and the increased momentum of the flow promotes scouring. In addition, the results show that scouring at the sidewalls is higher than in the middle of the cross-section. Finally, an empirical formula with root mean square error = 0.107 and R2 = 0.974 is proposed to predict the maximum scouring depth downstream from the stepped spillways. Comparisons were made between the proposed formula and experimental results. This comparison demonstrated that the formula can predict souring depth to within 3.86% and 9.31% relative and maximum errors, respectively.
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Paramadita, Tifarah Dayansabila, Nadia Azarine, Aburizal Azhar i Didit Puji Riyanto. "Local Scouring Visualization of Bed Channel Surface in Hydraulic Structure Using Surfer". Jurnal Teknik Sipil dan Perencanaan 24, nr 2 (31.10.2022): 140–49. http://dx.doi.org/10.15294/jtsp.v24i2.36499.
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Abstract. Water flowing in the river causes a scouring event that occurs at the bed channel. The existence of scouring will increase along with changes in the geometry of the river and obstacles such as the weir which are followed by local scouring around the weir. Local scouring often occurs downstream end of weir sill which weakens its construction. Scouring measurement was conducted to monitor the pattern of scouring that occurs. By using Surfer software, the scouring visualization through the Data Grid and 3D Surface can be seen. In this research, scour monitoring in the laboratory using open channels (flume) and MDO weir with fine aggregate material as the basis of the channel. The retrieval of scouring data was performed after installing fine aggregate and three times variations of flow discharge, then the data were processed using Surfer. The first flow used water level +3.50 with the material carried at 3.77%. The second flow used water level +4.50 with the material carried at 11.16%. The third flow used water level +5.70 with the material carried at 25.46%. So with the continuous method, the total material carried at 36.27% is equivalent to 12575.77 cm3.
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Zhang, Zhuoli, Wei Gao, Ping Li, Jie Liu, Yuanqin Xu, Xia Wei i Anlong Li. "Influencing Factors of Submarine Scouring and Siltation Changes in Offshore Area of Shandong Peninsula". Water 15, nr 3 (21.01.2023): 435. http://dx.doi.org/10.3390/w15030435.
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This study constructs a digital elevation model of the coastal waters of the Shandong Peninsula using GIS-based interpolation methods to investigate the 15-year characteristics of seabed scouring and siltation. It utilizes depth data of the Shandong Peninsula’s offshore area between 2004 and 2006 and 2017 and 2019. The results indicated that the Shandong Peninsula’s coastal-water seabed is characterized by integral siltation and local point scouring. In addition, the northwest Shandong Peninsula is dominated by siltation, mainly distributed between 2 and 5 m isobaths, with the largest siltation area located in Laizhou Bay. The net volume of siltation is 2.13 × 108 m3, the siltation rate is 0.152 × 108 m3.a−1, and the scouring is concentrated in the estuary and the west coast of Laizhou Bay. Scouring and siltation balance generally characterize the seabed in the northern coastal waters of the Shandong Peninsula, and the degree of scouring and siltation is weak. The siltation occurs primarily near the land area, while scouring occurs as the sea deepens. In the northeast of the Shandong Peninsula, the degree of scouring and siltation is extreme, and their distribution range is small, whereas in the south, siltation is distributed in large bays and straight coastal offshore waters, and its degree is relatively weak. At the southernmost end of the study area, the scouring and siltation in Jiaozhou Bay are spatially distributed and balanced. In reality, the key factors affecting the distribution of coastal-seabed scouring and siltation are materials transported by river sediment, coastal scouring, and human activities.
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Chang, Cheng-Kai, Jau-Yau Lu, Shi-Yan Lu, Kuo-Ting Hsiao i Dong-Sin Shih. "Using a PIV Measurement System to Study the Occurrence of Bursting in the Flow Over a Movable Scour Hole Downstream of a Groundsill". Water 12, nr 5 (14.05.2020): 1396. http://dx.doi.org/10.3390/w12051396.
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Generally, hydraulic structures are installed along with rivers in Taiwan to prevent erosion. The groundsill is one of the most common structures to protect the underlying riverbed. However, the occurrence of bursting during the process of scouring can intensify the disturbance of sediment in the bed, sometimes even causing hydraulic structures to collapse. This paper aimed to study the mechanisms of bursting, the effects of bursting, and the scouring exceedance probability of sediment movement. To study this topic, a particle image velocimetry (PIV) was used to measure the hydraulic characteristics of a scour hole under different flow conditions. The results showed that, firstly, the bursting and the sediment entrainment rate increased with time at the beginning. Secondly, when bursting occurred at the beginning stage of scouring, the averaged velocity of main flow was reduced by about 30% and the thickness of the riverbed was deepened by about 20%. Moreover, when scouring time was 15 min, at the location of maximum scouring depth, all the experimental groups carried the proximity values of the scouring exceedance probability that stuck to a range from 35% to 53% at the bursting stage. Therefore, the scouring exceedance probability of the bursting of the maximum scouring depth can be further applied to designs and to protect the foundation of hydraulic structures.
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Liu, Yan, Yong Zhou, Wen Lv, Haidong Huang, Guozhong Zhang, Ming Tu i Lin Huang. "Design and Experiment of Hydraulic Scouring System of Wide-Width Lotus Root Digging Machine". Agriculture 11, nr 11 (7.11.2021): 1110. http://dx.doi.org/10.3390/agriculture11111110.
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In response to the problems of small working width and low operating efficiency of existing hydraulic scouring lotus root harvesters, a wide-width hydraulic scouring system was designed based on a wide-width self-propelled lotus root harvester. The main parameters of the key components were determined through theoretical analysis of the water flow energy of the hydraulic scouring system pipelines. An experimental study was also carried out on the main factors affecting the working performance of this hydraulic scouring system. Through hydrodynamic simulation tests, the effect of nozzle type and constriction section structure on the turbulence intensity at the nozzle outlet and the pressure loss per unit mass of fluid between the nozzle inlet and outlet sections were compared and analysed. The test yielded conical-cylindrical nozzle geometry parameters for nozzle inlet diameter of 40 mm, shrinkage angle of 30°, nozzle outlet straight section length of 20 mm, nozzle outlet diameter of 16 mm, the nozzle had better flushing performance. Single-factor tests were carried out with nozzle outlet pressure, scouring angle and nozzle height from the mud surface as influencing factors. Based on the optimum effective scour depth, a three-factor, three-level Box–Behnken central combination design test was completed. The primary and secondary factors affecting the effective scouring depth were obtained in the following order: nozzle height from the mud surface, nozzle outlet pressure, and scouring angle. Finally, the performance test of the hydraulic scouring system was completed. Results showed that when the nozzle outlet pressure of 0.30 MPa, the scouring angle of 60° and the nozzle height from the mud surface of 0 mm, the effective scouring depth was 395 mm, the lotus root floating rate was 90% and the damage rate was 5%, which meet the requirements of lotus root harvesting operations.
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Kadono, Takuma, Shinichiro Okazaki, Yoshihiro Kabeyama i Toshinori Matsui. "Effect of Angle between Pier and Center of River Flow on Local Scouring around the Bridge Pier". Water 12, nr 11 (15.11.2020): 3192. http://dx.doi.org/10.3390/w12113192.
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In recent years, heavy rainfall disasters have caused frequent damage to bridge piers due to scouring and have resulted in the fall of bridges in many areas in Japan. The objective of this study was to investigate the effect of local scouring around the downstream of the piers on the local scouring around the center of the river flowing at an angle to the piers. It was found that when the center of the river flows at an angle to the piers, the scouring area becomes wider from the upstream to the downstream of the piers because of the longer inhibition width of the piers positioned perpendicular to the water flow. The downstream scouring depth tends to be smaller than the upstream scouring depth. In addition, the time to the onset of tilting deformation of the piers increases with the inhibition width of the piers positioned perpendicular to the flowing water.
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Zheng, Dong, Ruo-Yao Ding, Zheng Lei, Zhang Xingqun i Yu Chong-Wen. "Thermal properties of flax fiber scoured by different methods". Thermal Science 19, nr 3 (2015): 939–45. http://dx.doi.org/10.2298/tsci130329005z.
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Thermal properties of flax roves untreated and treated were characterized by differential scanning calorimetry (DSC) and thermal gravity analyzer (TGA) in order to understand their thermal behavior in more detail and to evaluate the effect of scouring processing on the thermal behavior. Flax roves were treated with six kinds of methods including biological scouring, one bath, two bath, bleaching, alkali scouring and industry chemical scouring as standards. Results showed that all treatments improved thermal stability of flax roves. The results indicated that glass transition temperature (Tg) decreased after scouring besides the sample by directly bleaching. It is more difficult to determine the endothermic peak of flax treated by chemical scouring in industry because it takes a very flat course. A distinct endothermic peak was observed for the untreated flax rove, while a distinct exothermic peak in different temperature interval was revealed for other four treated flax rove samples. For TGA analysis, thermal degradation of flax roves studied consists of three regions of the initial, main, and char decomposition, and the third stage consists of secondary weight loss and carbonization for flax roves with biological scouring, one-bath and two-bath. Besides, different residue left indicates that the bio-scoured flax roves are lost with volatile products and does not contribute to char formation. These results provide valuable preferences for mechanism and top value added application of bio-scouring in flax roves.
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Li, Qishun, Yanpeng Hao, Peng Zhang, Haotian Tan, Wanxing Tian, Linhao Chen i Lin Yang. "Numerical Study of the Local Scouring Process and Influencing Factors of Semi-Exposed Submarine Cables". Journal of Marine Science and Engineering 11, nr 7 (1.07.2023): 1349. http://dx.doi.org/10.3390/jmse11071349.
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Local scouring might result in the spanning of submarine cables, endangering their mechanical and electrical properties. In this contribution, a three-dimensional computational fluid dynamics simulation model is developed using FLOW-3D, and the scouring process of semi-exposed submarine cables is investigated. The effects of the sediment critical Shields number, sediment density, and ocean current velocity on local scouring are discussed, and variation rules for the submarine cables’ spanning time are provided. The results indicate that three scouring holes are formed around the submarine cables. The location of the bottom of the holes corresponds to that of the maximum shear velocity. The continuous development of scouring holes at the wake position leads to the spanning of the submarine cables. The increase in the sediment’s critical Shields number and sediment density, as well as the decrease in the ocean current velocity, will extend the time for maintaining the stability of the upstream scouring hole and retard the development velocity of the wake position and downstream scouring holes. The spanning time has a cubic relationship with the sediment’s critical Shields number, a linear relationship with the sediment density, and an exponential relationship with the ocean current velocity. In this paper, the local scouring process of semi-exposed submarine cables is studied, which provides a theoretical basis for the operation and maintenance of submarine cables.
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Najafzadeh, Mohammad, i Giuseppe Oliveto. "Scour Propagation Rates around Offshore Pipelines Exposed to Currents by Applying Data-Driven Models". Water 14, nr 3 (7.02.2022): 493. http://dx.doi.org/10.3390/w14030493.
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Offshore pipelines are occasionally exposed to scouring processes; detrimental impacts on their safety are inevitable. The process of scouring propagation around offshore pipelines is naturally complex and is mainly due to currents and/or waves. There is a considerable demand for the safe design of offshore pipelines exposed to scouring phenomena. Therefore, scouring propagation patterns must be focused on. In the present research, machine learning (ML) models are applied to achieve equations for the prediction of the scouring propagation rate around pipelines due to currents. The approaching flow Froude number, the ratio of embedment depth to pipeline diameter, the Shields parameter, and the current angle of attack to the pipeline were considered the main dimensionless factors from the reliable literature. ML models were developed based on various setting parameters and optimization strategies coming from evolutionary and classification contents. Moreover, the explicit equations yielded from ML models were used to demonstrate how the proposed approaches are in harmony with experimental observations. The performance of ML models was assessed utilizing statistical benchmarks. The results revealed that the equations given by ML models provided reliable and physically consistent predictions of scouring propagation rates regarding their comparison with scouring tests.
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Gao, Pengcheng, Xianyou Mou i Honglan Ji. "Refined Simulation Study on the Effect of Scour Environments on Local Scour of Tandem Bridge Piers". Sustainability 15, nr 9 (25.04.2023): 7171. http://dx.doi.org/10.3390/su15097171.
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Ice cover is a natural phenomenon unique to rivers in cold regions, and its existence is one of the reasons for the collapse of structural foundations of bridge piers across rivers. In order to understand the influence of different scouring environments on the hydrodynamics and sand bed morphology in the local scour holes around bridge pier foundations, this paper simulates the dynamic evolution process of the local scouring of tandem combination piers under open-flow and ice-cover environments, based on a turbulence model using the Reynolds-averaged Navier Stokes (RANS) method and a sediment transport model considering the slope collapse effect, respectively. This study also takes the vortex flow and shear stress distribution at different characteristic moments of the pier perimeter section as the penetration point to analyze the effect of the influence law of the scouring environment on the morphology and relative time scale of the scour hole, and makes a detailed comparison with the results of the indoor flume test. The results of this study show that: for local scouring in open-flow conditions, sediment initiation is doubly inhibited and the hydrodynamic forces in the scouring hole are weakened; the local scouring caused by ice cover contributes to the total scouring of the submerged pier within its coverage area, which significantly increases the depth and range of the local scouring hole; and, although the interaction of turbulent eddies and shear stress on the pier side is the main dynamic mechanism of the scouring generated around the pier, the two have a strong correlation. The results of this study, obtained by accurately quantifying the amount of eddies and shear stress around the pier, are the basis for the reasonable estimation of the maximum local scouring depth, which can provide a reference for the study of the evolution of the riverbed around submerged structures in cold areas and is essential to avoid structural damage to the piers and reduce the economic loss of traffic..
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Jung, Hyun-Hoon, Ji-Yun Seon, Tea-Hyoung Lim, Seung-Mok Lee i Seung-Kyun Park. "A Study of an Air Scouring Integral Immersed Hollow Fiber Membrane Module for Energy Saving and Membrane Fouling Control". Journal of Korean Society of Environmental Engineers 43, nr 7 (31.07.2021): 547–56. http://dx.doi.org/10.4491/ksee.2021.43.7.547.
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Objectives : MBR (Membrane BioReactor) is well established wastewater treatment that combines biological and physical method with high quality effluent. The purpose of this study is to utilize an air scouring integral immersed hollow fiber membrane module through efficient structural improvement developed to reduce membrane fouling. In addition, the scouring aeration was optimized to determine the energy savings.Methods : In this study, membrane fouling test was evaluated in various of scouring aeration flow with range of 40 to 140 m3 air/m2 projected area･hr and influent and effluent was analyzed by water quality standard.Results and Discussion : In scouring aeration test, effective membrane contamination control was possible with supplying 80 m3 air/m2 projected area･hr, scouring aeration rate gradually increased the differential pressure from below 60 m3 air/m2 projected area･hr, which accelerates the membrane contamination phenomenon. By reducing more than 20% of the existing general scouring aeration rate of 100~140 m3 air/m2 projected area･hr, electricity and maintenance costs can be reduced due to aeration control, and at the same time, it is confirmed that the technology has the same performance. The pilot test results of SJMBR with the developed module showed that the effluent was BOD of 1.4 mg/L, COD of 4.2 mg/L, SS of 0.7 mg/L, T-N of 5.56 mg/L, T-P of 0.56 mg/L, total coliform group of 0 ea/mL, and ecotoxicity of 0 TU, respectively.Conclusions : These results are combined, when using an air scouring integral immersed hollow fiber membrane module, it is expected to reduce the amount of scouring air by more than 20% by optimizing the supply of scouring air. In addition, it can also be determined by technology that satisfy the same permeability and treated water quality as existing technologies.
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Amanuel, Lami. "Combined scouring-bleaching of cotton fabric from wild yam root". Journal of Engineered Fibers and Fabrics 17 (styczeń 2022): 155892502210855. http://dx.doi.org/10.1177/15589250221085538.
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The conventional single-stage pre-treatment technique requires more electricity, is more expensive, polluting, harmful, and unhealthy because it uses artificial chemical compounds and auxiliaries. This research focuses on environmentally friendly and cost-effective textiles scouring-bleaching of cotton fabric with saponin and wild yam (Dioscorea villosa L.) root powder. The root of the wild yam contains alkaloids, amylose starch, and saponin. The investigations discovered important findings in cotton wet processing by developing a safe, water- and electricity-saving scouring method. Cotton fabric, along with the utilization of wild yam roots resulted in a significant cost effective method. As a result, it was used as a natural surfactant, foam stabilizer, and emulsifier in this scouring. The single stage Bot scouring was optimized with 40 g of untamed yam and a weight to volume (MLR in W/V) (weight of fabric to water) ratio of 1:10 at 80°C for 60 min on a pH of 5–7. The treatment’s effectiveness was measured using a weight reduction percentage and an absorbency test (a drop of water, capillary upward thrust, sinking time). In terms of weight reduction, water absorbency, capillary boost, as well as amazing friendliness, scouring cotton fabric with wild yam powder at optimized scouring conditions is comparable to scouring cotton fabric with 30% (at the weight of cloth) caustic soda. To verify the fabric samples’ resistance to microbiological development and strength maintenance, wild yam and Caustic soda scoured cotton fabrics were subjected to a soil burial test. The fabric sample scoured with wild yam has a much lesser standard deviations of toughness and elongation at break than the caustic soda scoured and untreated control samples. The Single stage scouring of cotton fabric with wild yam powder met the requirements for green scouring while also providing antibacterial qualities.
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Dwito Armono, Haryo, i Harish Wirayuhanto. "Experimental Study of Scouring Characteristic Around Hexagonal Artificial Reef". MATEC Web of Conferences 177 (2018): 01009. http://dx.doi.org/10.1051/matecconf/201817701009.
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Artificial reef is a structure placed underwater which has similar function with natural reef. Artificial reef can also serve as a submerged breakwater. When placed in shallow water, the structure is vulnerable to scouring and soil subsidence which cause structural failure. This paper present serial testings in Ocean Environment and Ocean Energy Laboratory, Ocean Engineering Department, ITS, to determine the scouring characteristic with variation of gap, and waves for 1: 10 model scale hexagonal artificial reef. The results of this research can guide the planning of structural protection against scouring. From a series of tests, it can be summarized that for 1 diameter gap reef distance, the maximum scouring occurs behind the structure, whereas for no gap distance, it occurs at the front of the structure. At the center of the structure, for no gap distance, sedimentation occurs dominantly, whereas for 1 diameter gap distance, scouring process occurs dominantly. The maximum scouring depth (5,3cm) occurs when the gap is equal to 1 diameter of reefs and minimum scour(2,9 cm) occurs when there is no gap between the reef.
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Seemork, Kattika, Jantip Setthayanond, Potjanart Suwanruji i Porntip Tooptompong. "Utilization of Spent Coffee Ground Oil in Eco-Friendly Scouring and Reactive Dyeing Processes for Cotton". Materials Science Forum 1005 (sierpień 2020): 85–92. http://dx.doi.org/10.4028/www.scientific.net/msf.1005.85.
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In this research, utilizing of Arabica spent coffee ground oil was investigated for textile processing applications including scouring and reactive dyeing for cotton. The spent coffee ground oil was extracted using hexane and its chemical compositions were analyzed. The synthesized biosurfactant from spent coffee ground oil was investigated for use in cotton scouring. The results showed that the biosurfactant could well work as a scouring agent for cotton. Much better water absorption and reduced yellowness on cotton were achieved but higher applied concentration was needed as compared with the commercial wetting agent. It was also found that scouring efficiency of the biosurfactant could be promoted by adding alkali i.e. sodium carbonate, into a scouring bath, resulting in a satisfactory scouring level. A study on utilizing spent coffee ground oil in reactive dyeing process informs that by incorporating the oil into an aqueous dyebath to create oil/water dual-phase dyeing system, the dye exhaustion and color yield of Reactive Red 120 dye obtained on cotton could be enhanced without adding salt. This promotes a development of salt-free reactive dyeing process.
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Jacobson, C. L., K. Bell i R. B. Besier. "Nematode parasites and faecal soiling of sheep in lairage: evidence of widespread potential production losses for the sheep industry". Animal Production Science 49, nr 4 (2009): 326. http://dx.doi.org/10.1071/ea08251.
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Diarrhoea (scouring) and subsequent faecal soiling of fleece are important economic and welfare issues for the sheep industry. Nematode worm infections are commonly implicated as a cause of scouring. This study aimed to investigate the extent of strongyle parasite infections, and identify any association with faecal worm egg count (WEC) and scouring in sheep from winter rainfall environments in Western Australia consigned to an abattoir. Faeces were collected from sheep with evidence of scouring and normal sheep (firm faecal pellets and no evidence of fresh diarrhoea on breech). A total of 4430 sheep from 113 lines of lambs (<12 months old), 10 lines of yearlings (12–24 months old) and 235 lines of adult sheep (>24 months old) were sampled between September and January. Mean WEC in lamb lines was 1525 eggs per gram (epg) of faeces with mean WEC >1000 epg in 42% of lines and >2000 in 22% of lines. Mean WEC in adult lines was 486 epg, with 13% lines having mean WEC >1000 epg. There was a trend (P = 0.099) to higher WEC in scouring lambs (2289 epg) compared with normal lambs (1523 epg). The scouring adult sheep had lower WEC (417 epg) compared with normal adults (482 epg, P = 0.021). The findings suggest that large strongyle infections were common in lambs consigned for slaughter. The low WEC in scouring adult sheep was consistent with the suggestion that a hypersensitivity to ingested nematode larvae, rather than large worm burdens, may be responsible for scouring in mature sheep.
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Williams, Ian. "The Scouring of Wellywood". Cultural Politics 17, nr 3 (1.11.2021): 347–61. http://dx.doi.org/10.1215/17432197-9305419.
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Abstract This article uses the work of brand theorists and New Zealand–based cultural critics to examine the circumstances that created the “Hobbit Law,” a New Zealand law aimed at busting local film industry unions. Branding logics created a struggle for authenticity around the importance of Middle-earth to New Zealand's national identity in the twenty-first century. This hybrid identity was then articulated as something that stood against labor actions by film industry workers, culminating in citizen marches against local labor. It closes by exploring ways that the importance of the brand as sense-making tool under neoliberalism might be reconfigured as something that might bridge the gap between media consumer and creative industry worker.
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Orpin, Peter. "Scouring in neonatal lambs". Veterinary Record 177, nr 8 (20.08.2015): 207–8. http://dx.doi.org/10.1136/vr.h4492.
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Lim, Siow-Yong, i Nian-Sheng Cheng. "Scouring in Long Contractions". Journal of Irrigation and Drainage Engineering 124, nr 5 (wrzesień 1998): 258–61. http://dx.doi.org/10.1061/(asce)0733-9437(1998)124:5(258).
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Kim, Juhea, Eun Kyung Choe, Su Yeon Kim i Sung Woo Nam. "Optimization of Enzymatic Scouring". Journal of Natural Fibers 3, nr 2-3 (8.08.2006): 155–68. http://dx.doi.org/10.1300/j395v03n02_10.
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Fruchart, Francis. "Scouring assessment in curves". La Houille Blanche, nr 2 (kwiecień 2016): 78–83. http://dx.doi.org/10.1051/lhb/2016022.
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SHORTER, S. A. "Discussion on Wool Scouring." Journal of the Society of Dyers and Colourists 34, nr 8 (22.10.2008): 163–66. http://dx.doi.org/10.1111/j.1478-4408.1918.tb01023.x.
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Turner, H. "Notes on Wool Scouring". Journal of the Society of Dyers and Colourists 50, nr 2 (22.10.2008): 47–48. http://dx.doi.org/10.1111/j.1478-4408.1934.tb01812.x.
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Karami, Hojat, Abdollah Ardeshir, Mojtaba Saneie i S. Amin Salamatian. "Prediction of time variation of scour depth around spur dikes using neural networks". Journal of Hydroinformatics 14, nr 1 (23.04.2011): 180–91. http://dx.doi.org/10.2166/hydro.2011.106.
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The maximum depth of scouring around spur dikes plays an important role in the hydraulic design process. There have been many studies on the maximum depth of scouring, but there is little information available on the time variation of scour depth. In this paper, the time variation of scouring around the first spur dike in a series was investigated experimentally. Experiments were carried out in four different bed materials under different flow intensities (U/Ucr). To achieve a time development of scouring around the first spur dike, more than 750 sets of experimental data were collected. The results showed that 70–90% of the equilibrium scour depths were occurring during the initial 20% of the overall time of scouring. Based on the data analysis, a regression model and artificial neural networks (ANNs) were developed. The models were compared with other empirical equations in the literature. However, the results showed that the developed regression model is quite accurate and more practical, but the ANN models by feed forward back propagation and radial basis function provide a better prediction of observation. Finally, by sensitivity analysis, the most and the least effective parameters, which affected time variation of scouring, were determined.
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Mladenovic, Nina, Petre Makreski, Anita Tarbuk, Katia Grgic, Blazo Boev, Dejan Mirakovski, Emilija Toshikj, Vesna Dimova, Dejan Dimitrovski i Igor Jordanov. "Improved Dye Removal Ability of Modified Rice Husk with Effluent from Alkaline Scouring Based on the Circular Economy Concept". Processes 8, nr 6 (30.05.2020): 653. http://dx.doi.org/10.3390/pr8060653.
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To improve the ability of the rice husk to purify colored wastewater, effluent from the alkaline scouring of cotton yarn was used immediately after the scouring (without cooling and additionally added chemicals) in order to remove the non-cellulosic silicon-lignin shield from the rice husk’s surface. This rice husk, with 93.8 mg/g adsorption capacity, behaves similarly as the rice husk treated with an optimized alkaline scouring recipe consisting of 20 g/L NaOH, 2 mL/L Cotoblanc HTD-N and 1 mL/L Kemonecer NI at 70 °C for 30 min with an adsorption capacity of 88.9 mg/g of direct Congo red dye. Treating one form of waste (rice husk) with another (effluent from the alkaline scouring of cellulosic plant fibers), in an effort to produce a material able to purify colored effluent, is an elegant environment-friendly concept based on the circular economy strategy. This will result in a closed-loop energy-efficient process of the pre-treatment of cotton (alkaline scouring), modification of rice husk using effluent from the alkaline scouring, dyeing cotton fabrics and cleaning its colored effluents with modified rice husk without adding chemicals and energy for heating.
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Li, Zhijiang, Tianru Yu i Lichao Yu. "Study on the scouring-bleaching technology of Xinjiang scutched flax". Journal of Engineered Fibers and Fabrics 15 (styczeń 2020): 155892502095765. http://dx.doi.org/10.1177/1558925020957650.
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This study explored and improved the optimal scouring-bleaching process of Xinjiang scutched flax, based on its characteristics and the scouring-bleaching process of existing mature flax. The physical properties, such as length, strength, split degree and fineness, and the chemical composition of Xinjiang scutched flax, such as the content of cellulose, lipowax, pectin, hemicellulose, water-soluble matter, lignin, etc., were measured and analyzed. The approximate range of bleaching process parameters was determined referring to the existing general flax scouring-bleaching process. Thirdly, the orthogonal experiment of three factors and three levels interaction is designed, and the optimal scouring-bleaching process scheme is obtained after analysis and verification.
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Qi, Hongliang, Weiping Tian i Haochi Zhang. "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 13, nr 22 (19.11.2021): 3281. http://dx.doi.org/10.3390/w13223281.
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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.
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Pan, Hua Li, Jiang Cheng Huang, Li Qin Wei i Guo Qiang Ou. "A Study on Scouring Laws Downstream of Debris Flow Sabo Dams". Applied Mechanics and Materials 170-173 (maj 2012): 2071–76. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.2071.
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Debris flow sabo dam is one of the most widely used debris flow control engineering. Its stability and safety operation is a key to controlling the effect of hazard prevention and avoiding secondary hazard. Because of the particularity of debris flow, it’s very hard to observe the process and morphology directly by field investigation. Although the scouring depth calculation method in hydraulic engineering provide an idea for debris flow sabo dam, but it can’t be used directly for the calculation of scouring depth downstream of debris flow sabo dams and foundation designation of the control engineering. This paper analyzed the influence factors of scouring laws downstream of debris flow sabo dams and the research status home and abroad. It suggests studying the scouring process and laws downstream of debris flow sabo dams by theoretical analysis, mechanical analysis and energy method combined with simulation experiments, establishing quantitative relationship between the scouring laws, limited depth, morphology, sediment transportation characteristics and the feature parameters of debris flow.
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Dhanistha, Wimala L., M. Rizky Syarifudin, Nathalia Damastuti i Ridho Akbar. "The Application of A Combined Computational Fluid Dynamics (CFD) Artificial Neural Network (ANN) to Increase The Prediction Accuracy of Sediment Grading in Subsea Pipes: A Literature Review". IJEEIT : International Journal of Electrical Engineering and Information Technology 5, nr 2 (17.09.2022): 70–77. http://dx.doi.org/10.29138/ijeeit.v5i2.1966.
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In recent years, the implementation of subsea pipelines for oil and gas transportation has increased. One of the important aspects of the design process of the subsea pipeline is scour prediction. Scouring causes the subsea pipeline to lose its support and is susceptible to failure due to deflection. This paper presents the result of a literature review of scouring-related research to obtain a method to increase scouring prediction accuracy. Based on the literature research, it is known that the errors found in Computational Fluid Dynamics (CFD) are mainly affected by the flow models. Existing flow models cannot fully represent the complexity of turbulent flow that occurs during the scouring process. Artificial Neural Network (ANN) can reduce the error value. But, the CFD-ANN hybrid methods can potentially decrease the error value by about 20% more than CFD. Therefore, the CFD-ANN hybrid method is expected to be a new method that could be used to predict subsea pipeline scouring in the oil and gas industry.
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MICHELSEN, VERNER, i MICHAEL W. PALMER. "Pegomya disticha Griffiths and P. cedrica Huckett (Diptera: Anthomyiidae)—first documented case of insects trespassing the silica barrier of Common scouring-rush, Equisetum hyemale L." Zootaxa 4718, nr 3 (7.01.2020): 355–70. http://dx.doi.org/10.11646/zootaxa.4718.3.4.
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Scouring-rushes (Equisetum sg. Hippochaete) are a group of horsetails with perennial aerial shoots strongly encrusted in silica. Accordingly, they seem to resist attacks from most herbivorous insects. Michelsen (2008) speculated that larval development of the European Pegomya terminalis (Rondani) and related anthomyiids takes place in specific scouring-rushes. Presently, we document that the larvae of two North American species related to P. terminalis attack developing shoots of Common scouring-rush, Equisetum hyemale L. Both species, Pegomya disticha Griffiths and P. cedrica Huckett, were found to coexist in a population of scouring-rush in Oklahoma. Various aspects of the life-history and morphology (3rd instar larva, male and female adults) for both species are described and documented by photos.
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Kadono, Takuma, Shinichiro Okazaki, Yoshio Kajitani i Masahide Ishizuka. "Development of a Model for Evaluating the Disaster Risk Around a Pier due to Local Scouring Based on the Observed Weather Information". Advances in Science and Technology 107 (28.06.2021): 49–54. http://dx.doi.org/10.4028/www.scientific.net/ast.107.49.
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Heavy rainfall disasters frequently damage bridge piers due to scouring, which resulted in collapse of bridges in many areas in Japan. In this study, we developed a model for evaluating the tilting risk of bridge pier due to scouring around the pier, which fluctuates depending on rainfall conditions based on machine learning. For evaluating the risk potential of scouring, we developed a model based on past disaster data due to scouring around the pier using a neural network. Furthermore, a sensitivity analysis was conducted using the parameters of explanatory variables of the developed model, river level, and distance from the water edge to the pier. The results showed that the disaster risk around the pier due to scouring increased with the increase in river level and decrease in the distance from the water edge to the pier. Additionally, a river level prediction model was developed using support vector regression with the precipitation time measured 5 – 8 h beforehand and river level measured several hours earlier as an explanatory variable. Furthermore, this study shows that the two developed models can be combined with each other to assess the disaster risk around the jetty due to scouring, which varies with rainfall conditions, based on the observed meteorological information.
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Purwanto, Purwanto, Arif Rakhman Suharso i Fajar Sari Kurniawan. "ANALISIS PENGARUH PERLAKUAN KIMIA TERHADAP MORFOLOGI DAN GUGUS FUNGSIONAL SERAT SISAL". Newton-Maxwell Journal of Physics 2, nr 1 (29.04.2021): 22–26. http://dx.doi.org/10.33369/nmj.v2i1.15262.
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Morphological and functional group analysis was carried out to study the appearance of micro and molecular structures contained in sisal fibers before and after chemical scouring and bleaching treatment. The scouring and bleaching process lasts for 1 hour with continuous stirring using a magnetic stirrer. Scouring was carried out with 6% NaOH solution while Bleaching was carried out with a solution of 10 g / L NaOH and 100 ml / L H2O2. Scanning Electron Microscopy (SEM) was used to identify the surface appearance and diameter of the fibers before and after the scouring and bleaching processes. Fourier transform infrared (FTIR) spectroscopy is used to identify functional groups in fibers. The Bleaching process shows that the functional groups identified are the same as those of pure cellulose or alpha cellulose, namely -CH2, C-O, C = C, -CH3, C?C, and -OH, C-H. Sisal fibers with a diameter between 100 - 150 µm break down (fibrillate) into smaller fibers after the scouring (diameter: ?12 µm) and bleaching (diameter: ?7µm) processes. Thus, scouring and bleaching have caused significant changes in the morphological and microstructure of the fiber surface and also the functional groups that the sisal fiber has after the bleaching process is the same as pure fiber.
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Guo, Can, Baicang Liu, Chen Chen, Haiqing Chang, Shuai Wang, Meibo He i John Crittenden. "Development of an efficient approach for separating bubbles and flocs in a submerged membrane ultrafiltration process". Water Supply 18, nr 3 (25.07.2017): 808–18. http://dx.doi.org/10.2166/ws.2017.153.
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Abstract This work was carried out to investigate the impact of air scouring and membrane configuration on ultrafiltration (UF) performance in a hybrid process of coagulation-UF. To eliminate the adverse impacts of air scouring, the concept of separating flocs in the submerged membrane module was proposed. The performance of three types of floc separation devices, including a cylinder module, a module without a floc separation device and a stacked inclined plate module, was compared. In the coagulation-UF process (i.e., without air scouring), the average transmembrane pressure (TMP) growth rates of the cylinder module, the module without a floc separation device and the inclined plate module were 0.58, 0.76 and 1.38 kPa/h, respectively, indicating lighter membrane fouling of the former two membrane configurations. In the coagulation-air scouring-UF process (with an air scouring rate of 35 mL/min), the stacked inclined plate module showed better effluent water quality (lower UV254) and floc integrity (the floc size was about twice that of the other two configurations). Further, the optimization of the air scouring rate was conducted when the inclined plate module was used, and the optimal value was determined to be 60 mL/min for air rates ranging from 0 to 100 mL/min.
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Sun, Dong Po, Li Sha Wang i Peng Tao Wang. "Study on the Local Scouring of the Bridge with Sediment Control Dam". Applied Mechanics and Materials 204-208 (październik 2012): 2230–35. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2230.
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Based on the characteristics of local piers scouring after built the sediment control dam in the downstream of the bridge, by the monomer model experiment of flume, sixty groups of local piers scouring experiments have been carried on.The principle and the influence factors of the local piers scouring have been analyzed. The results of series model experiments show that, with the sediment control dams, the local scouring of the piers, on one hand, is influenced by the approach velocity, down-shearing vortex, dimension of the piers, diameter and gradation of the bed sand; on the other hand, it is affected by the elevation of the dam and distance between the pier and the dam. Therefore, the concept of “control slope” is introduced in order to reflect the impacts of the sediment control dam to the piers. Based on the theoretical deduction and dimensional analysis, the equation, which is used to calculate the local scouring with no-uniform bed sand, is acquired by multivariate regression analysis, has been testified by the flume experiment and has got a good result. The optimum value of control slope and the equation of local piers scouring with that dam provide valuable references for bridge flood-control design of the shallow foundation with downstream sediment control dam.
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Smith, Edward, Q. Zhang, B. Farrand, V. Kokol i Jin Song Shen. "The Development of a Bio-Scouring Process for Raw Wool Using Protease". Advanced Materials Research 441 (styczeń 2012): 10–15. http://dx.doi.org/10.4028/www.scientific.net/amr.441.10.
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The use of protease in the raw wool scouring process was investigated. Both native protease and an enlarged protease prepared by chemical modification were used. It was demonstrated that enzymatic treatment with protease in the scouring process (bio-scouring) can achieve cleaning of the fibre and modification of the cuticle layer leading to shrink-resistance. A reduction of lipid content was found and led to an improvement in dyeability of the fibre.
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Udhayamarthandan, S., i J. Srinivasan. "Integrated enzymatic and chemical treatment for single-stage preparation of cotton fabrics". Textile Research Journal 89, nr 19-20 (23.01.2019): 3937–48. http://dx.doi.org/10.1177/0040517518824845.
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Starch sized 100% cotton woven fabrics need desizing, scouring and bleaching treatments prior to coloration and finishing. Traditionally, alpha-amylase-based enzymatic desizing and combined scouring and bleaching with an alkali, surfactant and H2O2 are used. Constant research is conducted on combining the desizing, scouring and bleaching processes into a single step by many researchers. This paper aims at combining enzymatic desizing and alkaline H2O2 scouring cum bleaching with a surfactant and stabilizer. The treatment resulted in efficient desizing, scouring and bleaching, leading to excellent size removal, absorbency, seed/mote removal and whiteness index levels, and comparable tensile and tear strength levels to that of the two-step process. The dyeability aspects were comparable in terms of surface color strength ( K/ S), color difference ( ΔE) and fastness ratings. Around 50–75% savings in water, energy, power, time and effluent generation were reported. The chemical oxygen demand, biological oxygen demand, total dissolved solids, pH and turbidity values of the resulting effluent were found to be remarkably lower. The technology was also tested industrially and found to be successful.
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Wang, Zhi De, Jing Li, Zhen Wei Guan, Yu Zhong Zhang, Yan Wang i Zhi Yong Wang. "Fabrication and Evaluation of an Amino Modified Epoxy Coating for Anti-Scouring and Anti-Corrosion Application". Materials Science Forum 815 (marzec 2015): 684–89. http://dx.doi.org/10.4028/www.scientific.net/msf.815.684.
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Excellent performance is necessary for compressor blade when aircraft engine serves in harsh environment, where it will go through scouring from jet-stream and extraneous sand, shaking of blades and corrosion from corrosive medium, taking moisture, salt, SO2 for example. Due to the shortage of scouring resistant and anti-corrosion property, shedding of damaged coating is a fundamental reason for the breakdown of aircraft engine blades, which is also the technique bottleneck that hinders the engineering application of compressor blades. Aiming at such problems, an amino modified epoxy coating which performed excellent scouring resistent and anti-corrosion property was fabricated on blades in this paper. Physical properties, anti-corrosion performance, abrasion resistant profiles and scouring resistant test were comprehensively evaluated. Results showed that the coating displayed a high hardness (pendulum hardness 0.9), overlong pot life, well anti-corrosion performance and excellent scouring resistant property. Pot life extends from 8h which is that of common coatings to 36h, so that it is benefit to large scale coating in engineering application. The anti-corrosion performance is similar to traditional aluminizing/inorganic silicate protect coatings, and abrasion resistant property is superior to common protect coatings. Moreover, scouring resistance performance is 3~4 times that of traditional coatings. Hence, such protective coatings could ensure the long lasting of blades protection.
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Song, Zixuan, Lijie Ma i Dehua Liu. "Research on Scour Resistance based on Ecological Concrete Slope Protection Method". Frontiers in Science and Engineering 3, nr 7 (22.07.2023): 70–74. http://dx.doi.org/10.54691/fse.v3i7.5322.
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In order to study the anti-scouring performance under the ecological concrete slope protection method, tall fescue was selected for vegetation experiments and anti-scouring experiments to analyze the effect of anti-scouring performance under different slope, different rainfall and different concrete thickness conditions, and concluded that the runoff erosion increases with the increase of slope and rainfall, while the concrete laying thickness has little effect on the runoff erosion. It also provides new research ideas and research directions for engineering applications.
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Plesiński, Karol. "GRAVEL BED RIVER SCOURING ANALYSIS DOWNSTREAM OF BLOCK RAMP (EXAMPLE FROM THE PONICZANKA STREAM IN PONICE VILLAGE)". Zeszyty Naukowe Uniwersytetu Zielonogórskiego / Inżynieria Środowiska 167, nr 47 (1.10.2017): 77–87. http://dx.doi.org/10.5604/01.3001.0010.8689.
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The work describes the scouring process downstream of boulder block ramps on Poniczanka Stream in Ponice village. The depth of the downstream scouring rate was calculated using empirical formulae due to different authors. The results of the calculations were verified basing on the field measurements. Finally only those formulae which results were most consistent with field observations and those with were the worst consistent with field observations are presented along a paper. Thus the aim of the study was to verify the existing formulae of the scouring depth calculation downstream of block ramp hydraulic structure on the basis of the results of field research. It was found that the empirical relationships for calculating the scouring depth in observed case are not satisfied enough, however they can be used for comparative analysis for designers.
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Agus Tri Windarta, Muchtar, i Didik Purwantoro. "Pengaruh Penempatan Tirai Segitiga Lurus dan Segitiga Lengkung terhadap Kedalaman Gerusan Lokal". INERSIA lnformasi dan Ekspose Hasil Riset Teknik Sipil dan Arsitektur 12, nr 2 (16.01.2017): 164–72. http://dx.doi.org/10.21831/inersia.v12i2.12591.
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ABSTRACT Pier is part of the bridge which is the most important because it serves to hold the weight of bridge and the weight of the charge passing through it. Then development on the pier of the bridge particularly on stability against local scouring due to the influence of the flow of river water to note. This test aims to find out the influence of variations in the placement of the curtains triangle straight and curved triangle. This study using models pier observation as a means of testing with parameters of depth of flow and discharge of water, with a height of 10 cm, the sand discharge flow 1.09 l/sec. The test Objects this uses pipe PVC with a diameter of 2,6 cm high pier, 25 cm as the pier for testing. Testing it uses a standard tilting flume. Testing done twice with the variation form of the curtain striangle straight and curved triangle. Based on the results of testing conclusion can be obtained that depth of scouring at point A on the pier using a variation of the curtain triangle straight can reduce the scouring of 70% while in the triangular curve blinds reduce scouring amounted to 66%, the depth of scouring in point B and D on the pier using a variation of the curtain triangle straight can reduce the scouring amounting to 72% while in the triangular arch blinds reduce the scouring amounting to 51%, and depth of scouring in point C on the pier using a variation of the triangle straight curtain can reduce scouring of 88% while in the triangle blinds arch reduce the scouring of 66%. Keywords: depth of scouring, variety of curtains. ABSTRAK Pilar merupakan bagian dari jembatan yang paling penting karena berfungsi untuk menahan berat badan jembatan itu sendiri dan berat muatan yang melintasinya. Maka pembangunan pada pilar jembatan terutama pada kestabilan terhadap gerusan lokal akibat pengaruh aliran air sungai perlu diperhatikan. Pengujian ini bertujuan untuk mengetahui pengaruh variasi penempatan tirai segitiga lurus dan segitiga lengkung. Kajian ini menggunakan model pilar sebagai alat pengamatan pengujian dengan parameter kedalaman aliran dan debit air sama, dengan ketinggian pasir 10 cm, debit aliran 0.99 lt/det. Benda uji ini menggunakan pipa PVC dengan diameter 2,6 cm, tinggi pilar 25 cm sebagai model pilar untuk pengujian. Pengujian ini menggunakan standard tilting flume. Pengujian dilakukan dua kali dengan variasi bentuk tirai segitiga lurus dan segitiga lengkung.Berdasarkan hasil pengujian dapat diperoleh kesimpulan bahwa kedalaman gerusan di titik A pada pilar yang menggunakan variasi tirai segitiga lurus dapat mengurangi gerusan sebesar 70% sedangkan pada tirai segitiga lengkung mengurangi gerusan sebesar 66%, kedalaman gerusan di titik B dan D pada pilar yang menggunakan variasi tirai segitiga lurus dapat mengurangi gerusan sebesar 72% sedangkan pada tirai segitiga lengkung mengurangi gerusan sebesar 51%, dan kedalaman gerusan di titik C pada pilar yang menggunakan variasi tirai segitiga lurus dapat mengurangi gerusan sebesar 88% sedangkan pada tirai segitiga lengkung mengurangi gerusan sebesar 66%.Kata kunci: kedalaman gerusan, variasi tirai.
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Tian, Yun, Yong Wu, Hao Wang, Hongtao Li, Lindong He i Hong Zhao. "A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope". Applied Sciences 13, nr 8 (18.04.2023): 5066. http://dx.doi.org/10.3390/app13085066.
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In this paper, scouring shear failure theory is optimized based on the gangue slope near the thermal power field in Baiguo Town, Panzhou City, Guizhou Province. Based on the particle flow PFC (particle flow code) 3D fluid–solid coupling method, the scouring failure mechanism of ditch no. 5 of the gangue slope is comprehensively analyzed from the perspectives of the failure mode, displacement, motion track, and stress–strain. We consider the scouring shear theory in respect of (c, φ); this theory is dominated by two types of scouring intensity factors and can effectively explain the internal mechanisms of gully formation. The rainfall scouring failure of gangue slopes can be divided into four stages: (1) integral splash erosion and local pitting at the bottom of the slope; (2) erosion diversion and pitting in the slope; (3) the tributary–slope crest extension schist erosion stage; and (4) integral gully erosion and the landslide stage. The failure process is not only characterized by discontinuous failure but also occurs in the order of bottom–middle–branch–top. A three-section stepped effect is observed during the process in which the gangue is scoured and destroyed, which fully verifies the intermittent characteristics of the scouring and destruction of gangue slopes. During the whole process, the maximum displacement is concentrated at the top of the slope, and its proportions are as follows: top of the slope > tributary > middle of the slope > foot of the slope. The peak displacement of the slope crest in the horizontal Y-direction accounts for 41.76%, and that in the Z-direction accounts for 45.84%. Scouring deposits can be divided into the arc erosion deposit mode and the sector erosion deposit mode. Mainstream gullies primarily control whether deposits are characterized as arc or straight erosion deposits. The later stage of the second phase of scouring is the incubation period of the tributary gully. The large accumulation makes the stress at the bottom of the slope increase sharply, and the fluctuation value is between 2 and 6.8 MPa. The generation of the branch notch is mainly determined by X-direction stress, and 8.6 MPa is the critical stress. In efforts to prevent and control rainfall and landslide, the slope foot area should be preferentially protected, and the soil mass in the slope should be reduced to prevent the maximum energy fluctuation caused by scouring, so as to prevent significant displacement damage of the slope top.
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Cho, Yong Jun. "Numerical Analysis of Modified Bed-profiles due to the Presence of a Rubble Mound Breakwater using Physics-Based Morphology Model[SeoulFoam]". Korea Society of Coastal Disaster Prevention 8, nr 3 (30.07.2021): 151–63. http://dx.doi.org/10.20481/kscdp.2021.8.3.151.
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Among the many scouring-protection works near a rubble mound breakwater, stacking armoring rocks in multiple or single layers are most popular. The rationale of these scouring-protection works is based on the Equilibrium regime or the maximum scouring depth. However, considering natural beaches, which constantly change their shape according to sea waves conditions, the equilibrium regime or the maximum scouring depth mentioned above seems to foot on the fragile physical background. In this study, in order to test the above hypothesis, numerical simulations were carried out on the partial reflection from the slopes of rubble mound breakwater, and its ensuing standing waves formed in the front seas of a breakwater, the change in the bed profiles due to the formation of standing waves, and scouring depth at the base of a rubble mound breakwater. In doing so, numerical simulations were implemented using OlaFoam, an OpenFoam-based toolbox, and SeoulFoam (Cho, 2020), a physics-based morphology model. Numerical results show that the wave length of sand waves is closely linked with the incoming wave period, while amplitudes of sand waves are determined by incoming wave height. Moreover, the seabed profiles underwent significant changes due to the presence of a rubble mound breakwater. It was shown that the size of sand waves increased when compared before the installation, and the shape of sand waves is getting skewed toward the shore direction. It was also shown that as exposure time to standing waves increased, the amplitude of sand waves also increased, and the scouring depth near the base of a breakwater increased. These results are contrary to the Equilibrium regime, and the scouring prevention works based on the stacking of armoring rocks should be re-evaluated.
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Gao, Pengcheng, Xianyou Mou i Honglan Ji. "Simulation Study on Local Scour Characteristics of Tandem Bridge Piers in a Straight River under a Changing Environment". Sustainability 15, nr 15 (31.07.2023): 11776. http://dx.doi.org/10.3390/su151511776.
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Hydrodynamics is a common manifestation that causes natural scouring of riverbeds, and it is one of the factors that exacerbate the natural disasters of local scouring of bridge piers, causing sustainability of environmental changes in the water. The evolution pattern and scour characteristics of the bed surface around the submerged structures under different scouring conditions vary greatly. In order to investigate the scour mechanism, the reformed group (RNG) turbulence model in computational fluid dynamics (CFD) simulation software (v11.2) was used to simulate the scour under the clear-water scour and live-bed scour environments, and different scour morphology characteristics around the tandem piers under the clear-water scour and live-bed scour environments were obtained in the final simulation. By capturing the cross-sectional vortex and bed shear stress during the scouring process, the characteristic pattern of scouring topography around the pier and the relationship between the scour hole structure scale were analyzed, and the relationship equation between the development of scour depth and time scale was established. The study shows that: under the clear-water scouring environment, the sediment transport rate lags behind, but the contribution time is superior; under the live-bed scouring environment, by the shading and reinforcement influence of the upstream piers, the extent and development of the downstream pier surrounding the scour hole is small; the development trend of the maximum sediment transport rate of the scour hole and the great value of the shear stress is more synergistic, and the peri-pier eddy is positively correlated with the bed shear stress; through the regression equation to compare the relevant test and simulation results, the two are in good agreement, indicating that the simulated local scour evolution law is consistent with the actual law.
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Lufira, R. D., S. Marsudi, S. Agustien i A. Khosin. "Determining the Depth of Local Scouring in a Downstream Energy Dissipation in the Physical Model Test". IOP Conference Series: Earth and Environmental Science 930, nr 1 (1.12.2021): 012022. http://dx.doi.org/10.1088/1755-1315/930/1/012022.
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Abstract Karangnongko Weir is planned to be located in the Bengawan Solo River (Lower Solo River Basin) about 15 km downstream of the confluence of Bengawan Solo River with the Madiun River in Ngelo Village, Margomulyo Sub-District, Bojonegoro Regency, and Ngrawoh Village in Kradenan Sub-District, Blora Regency. This study aims to determine the Depth and pattern of scouring in downstream energy dissipation through physical model tests based on initial planning. Downstream protection of energy dissipation in the original design model combines 50 m of riprap rocks and 50 m of riprap concrete for a total length of 100 m of protection. The maximum scouring pattern occurred at elevation + 17.64 m, where the scouring was 4.36 m deep, from the planned essential height of Height 00 m. Thus, the downstream protection of energy dissipation was extended to 112 m in riprap concrete blocks for the final design model. Scouring at the end of riprap was 3.04 m, the original elevation of the river bottom of + 22.00 m, down to + 18.96 m. It is concluded that the protection is effective in reducing scouring by up to 30.27%.
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Gao, Qingfei, Biao Wu, Renzhi Wang, Jiaqiang Zhang, Binqiang Guo i Jun Li. "Investigation of the Dynamic Performance of a Large-Span Suspension Bridge Influenced by Scouring Based on Vehicle-Bridge Coupled Vibration". Shock and Vibration 2020 (11.11.2020): 1–12. http://dx.doi.org/10.1155/2020/6656247.
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To study the damage of bridge pile foundations caused by scouring, two damage mechanisms of scouring are proposed in this paper. Considering the vehicle-bridge coupled vibration in terms of two aspects of the scouring depth and erosion depth, the vertical and transversal dynamic characteristics and dynamic responses of the bridge are studied under different cases for the most sensitive vehicle speed. The dynamic characteristics include the 1st and 2nd vibration modes of the vertical and transversal directions of the bridge. The dynamic responses include the vertical and transversal dynamic load allowances and acceleration of the bridge. The souring depth is more sensitive than the erosion depth, and the 2nd vertical mode is most substantially influenced by scouring and erosion. Because of the small value of the natural frequency of the vertical vibration modes, the transversal vibration modes may be more convenient to obtain. The study of the dynamic responses shows that the scouring depth can be represented by the dynamic load allowance in the middle of the span’s section and the erosion depth can be characterized by the dynamic load allowance at the quarter location of the span’s section.
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Yang, Ming Xia, i Rong Zhou. "Research on Degumming Experiment of Corn Bracts". Advanced Materials Research 550-553 (lipiec 2012): 1242–47. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.1242.
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In this paper, using chemical degumming method on corn bract fiber degumming experiment, in order to find a more suitable degumming process of corn bracts and to realize the development and utilization of corn bract fiber. "Pre-oxygen pretreatment + Two scouring" chemical degumming method was used, and the optimal combination of process parameters was found out by using orthogonal experimental design method. Optimal pretreatment parameters: H2O2 6g/L, Pre-treatment time 30min, Temperature 40°C; Two Scouring optimal parameter combinations: NaOH 16g/L, Temperature 80 °C, Scouring time 150min.
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Guo, Xingfei, Yaowu Wang, Hongwei Zhang, Pengfei Li i Cong Ma. "Numerical and experimental investigation for cleaning process of submerged outside-in hollow fiber membrane". Water Science and Technology 76, nr 6 (28.04.2017): 1283–99. http://dx.doi.org/10.2166/wst.2017.228.
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Membrane fouling has limited extensive applications for hollow fiber membranes in water treatment. Backwashing and air scouring can effectively solve this problem in the submerged outside-in hollow fiber membrane system. In this study, variation of the fouling layer on the membrane surface during backwashing and the impact of shear stress caused by air scouring on fouling removal were investigated through computational fluid dynamics (CFD) simulation. The backwashing and air scouring process were simulated using CFD and the results were verified by experimental studies. The results of experimental studies are in accordance with the simulation results. During the backwashing process, the velocity profile inside the reactor was presented, and visualization of the particle movement to illustrate the dynamic peeling process of the fouling layer on the membrane surface was also shown. The formation of uneven cleaning reveals that the upper region of the fibers has an excellent cleaning effect during backwashing. After that, the supporting role of air scouring was investigated in the study. It is concluded that the lower part and the middle region of the fibers suffer greater shear stress by analyzing the velocity contours and vectors, and the analysis results indicated that air scouring can further remove membrane fouling.