Drainage Ability Research Articles

Potential Impact of Agronomic Conditions on the Drainage Ability of a Short-sided Two-way Sloped Field

Potential Impact of Agronomic Conditions on the Drainage Ability of a Short-sided Two-way Sloped Field

COMPARE INFLUENCES OF HORIZONTAL AND VERTICAL MSE WALL DIMENSIONS WITH GEOCOMPOSITE BACK DRAINAGE SYSTEM TO MAXIMUM STEADY STATE PHREATIC LEVEL

Nowadays, with serious risks to the mechanically stabilized earth (MSE) instability especially for soil mass behind the wall face caused by heavy rainfall. Come from high drainage ability, geocomposite is regarded as an appropriate material for drainage purposes in many geotechnical structures, including MSE walls. However, there are insufficient researches investigated MSE wall geometry design especially with wall dimension oriented follow 2D dimension as horizontal and vertical. This paper presents a series of PLAXIS numerical simulations to investigate the influences of MSE wall dimensions and drainage capacity on seepage responses inside the protected zone of the wall. The research results indicated that the distance from the upstream water source to the drainage face (L) influences most to the maximum steady state phreatic level (ho) variation inside the protected zone. In total comparison that shown the horizontal wall dimensions have more affects on ho drops than vertical wall dimensions.

Examination on Water Management Method in the Same Electrode in PEFC

Recently, Polymer Electrolyte Fuel Cells (PEFCs) are beginning to be used in various fields as a clean energy source because they don’t emit carbon dioxide during operating. However, PEFCs have some problems such as a cost reduction and durability etc. Generally, PEFCs need a humidification system to avoid dryness of membrane during operating, but the amount of energy supplied to the humidifier is large, and reduces a system efficiency, and the cost of the humidification system is also necessary. And, the steam in the cathode gas becomes supersaturation in the vicinity of gas outlet, and thereafter it is condensed because the steam is generated by the cell reaction and is multiplied toward the gas outlet. Because the use of humidifier increases the amount of condensation and causes the water management issues such as the flooding phenomenon and the plugging phenomenon in the vicinity of gas outlet, these issues make the cell voltage unstable. Our laboratory has proposed the Self Water Management Separator (SWMS) with a bypass channel to solve these issues. The SWMS moves excess water from gas outlet to gas inlet through the bypass channel where filled water absorption material. Excess water was absorbed by a capillary phenomenon of water absorption material, and it moved from gas outlet to gas inlet by a concentration difference of water. The previous study clarified that the bypass position depended on the operating condition, and the optimum bypass position under non-humidifying and non-heating conditions (w/o humidifier and heater) was at gas inlet. Therefore, this study aims to select the optimum water absorption material for SWMS. The specification demanded for the water absorption material is a water supply and drainage ability and a handling ability. We prepared four water absorption material such as polyvinyl alcohol sponge (PVA), diatomite powder, cellulose fiber insulation (CFI), and EM diatomite grain. Here, cellulose insulation is a wood fiber insulation material. The SWMS was installed in only cathode side and a single serpentine was applied to both separators as a gas channel. The cell performance was evaluated by IV performance and Cole-Cole plots of AC impedance method under the standard condition and a durability test condition. Here, the standard condition and the durability test condition mean 0.3A/cm2 of the current density and Uf/Uox=70%/40% of the fuel/oxidant gas utilization, and 0.2A/cm2 and 45%/25%, respectively. The cell temperature of both conditions was 30°C. As a result, the resistance polarizations of the cell with SWMS on all water absorption material were equivalent or smaller than that of the cell w/o bypass channel as shown in Fig.1. Especially, the initial performance of the cell where PVA or CFI was filled in the bypass channel was better than that of others in a high current density region. The activation polarization of the cell with PVA was the smallest, and it has hardly changed on the durability test. Therefore, because PVA uniforms the humid condition in the cell, consequently the activation and resistance polarizations are improved by the increases of three phase interface and the ion conductivity. However, although the IV performance of the cell with CFI was almost the same as that of PVA, the resistance and activation polarizations were a little large compared with others and the diffusion polarization began to grow up. Because CFI has a high water supply and drainage ability, it deprived the membrane and three phase interface of necessary water, consequently it deteriorated the cell performance. Therefore, we decided that PVA is the most suitable as the water absorption material of the bypass channel from viewpoints of cell performance and handling ability. Figure 1

Quantifying and Incorporating the Benefits of Wicking Geotextile into Pavement Design

Geotextiles have been widely used in pavement systems for reinforcing base and subgrade layers. However, the capillary break effect minimizes the benefits of reinforcement due to excess pore-water pressure accumulation at the soil–geotextile interface. In contrast, the wicking geotextile has the ability to provide superior lateral drainage ability and overcome the limitations of nonwicking geotextiles. Both field and laboratory tests have proven the efficiency of the wicking geotextile to dehydrate road embankments. However, the benefits of wicking geotextiles have not been considered in the existing pavement design methods. This paper aims at comparing the drainage performance of pavement structures without any reinforcement, with a nonwicking geotextile, and with the wicking geotextile. Firstly, a coupled hydromechanical model is proposed to predict pavement performance under saturated and unsaturated conditions. The effective resilient modulus data were obtained from the numerical model, and the methodologies of incorporating the benefits of the geotextiles into the design guides are discussed in detail. Simulation results indicated that by using the wicking geotextile, the thickness of the base course could be reduced by nearly 50% based on a standard US design guide, and the rutting depth reduced by 35% according to a standard pavement design guide. However, the nonwicking woven geotextile caused a detrimental effect to the pavement structure due to the capillary break effect, especially in a situation with a shallow water table.

Screening of a Mannosylerythritol Lipids Producing Strain and Analysis on Its Products

The purpose of this study is to improve the environmental pollution problem, the strains which can produce glycolipid biosurfactant and degrade petroleum hydrocarbons efficiently were screened out in this study. Six strains of glycolipid-producing fungi were isolated from the surface of apple skin by the methods of blood plate and oil plate. After comparing the oil drainage ability of each strain and using PCR to amplify the key genes for the synthesis of glycolipid surfactants, we screened a fungus K6 with emtl sequence. The strain was identified by morphological, physiological and biochemical tests and molecular phylogenetic analysis (5.8S, ITS1, ITS2). Its metabolites were analyzed by TLC and HPLC. The strain was identified as Pseudozyma churashimaensis, which could produce mannose and erythritol. The experiment of petroleum hydrocarbon degradation shows that strain K6 has strong emulsifying ability and the ability of degrading petroleum hydrocarbon. Strain K6, with the strong ability in producing biosurfactants and degrading petroleum, will have broad application prospects for bioremediation of petroleum contaminated environment.

ANALYSIS OF THE CARRYING CAPACITY OF URBAN DRAINAGE DIMENSIONS

The rain that fell in the city of Cirebon, especially the drainage on Jalan Pemuda, could not accommodate and drain the water so that it could create puddles on the roads and surrounding areas. Hourly rain intensity, planned flow rate and channel cross-sectional dimensions are the first steps for flood prevention. Hydrological analysis is used to calculate the discharge capacity of the drainage plan. The results were then analyzed the dimensions of the channel, the drainage ability to accommodate the falling rainwater where Qs is bigger than Qp. the channel discharge has not been able to accommodate the Q plan in the channel so that there will be a runoff of 17.759%. So to anticipate runoff, it is necessary to have a channel improvement plan of 33.477%. In addition to channel improvement solutions, arrange and define the boundaries of water storage areas by measuring and mapping boundaries and issuing regulations that prohibit or limit the construction of buildings that can reduce the ability of areas to store and absorb rainwater by referring to the basic building coefficient (KDB) permitted as stated in the RT/RW.

Prospects of using penetrated cement concrete in the construction of transport infrastructure objects

This article presents the analysis of the international experience of the use of pervious concrete in transport infrastructure. It provides the advantages and disadvantages of the material and the results of personal laboratory tests of relevant concrete samples. The object of the research is the use of pervious concrete in the construction of transport infrastructure. The objective of the paper is to justify the use of pervious concrete in the construction of transport infrastructure by analyzing previous international experience and lab tests of the corresponding concrete samples. Research methods included a analysis of the international and domestic literature, the evaluation of the experience in the use of the pervious concrete, and laboratory tests of the corresponding concrete samples. A review of the world experience connected with research of pervious (draining) concrete, installation and operation of layers of aerodrome surface made of it, proved their technical and economic relevance and effectiveness of their application. Pervious concrete is a material with high open porosity, which provides good sound-absorbing properties and drainage ability together with roughness, smoothness, and transverse friction. These are advantages of pervious concrete pavements, according to foreign studies: a rapid removal of water from the surface of the pavements in case of rain and improved drainage of road and airfield pavements reduce the risk of aquaplaning vehicles and increase traffic safety in rainy weather; increased and stable surface roughness; reduced level of noise provided by vehicles. The draining ability of the pavements makes it almost dry. It also has a high degree of sound absorption. The results of the article can be implemented in various technologies of construction and repair of transport infrastructure. The search for the optimal composition of pervious concrete for its further use in the technology of construction and repair of various objects is the main purpose of predictive assumptions about the development of the object of study.

Development of Quantitative Field Drainage Ability Evaluation Method Based on Monitored Soil Water Content of Converted Paddy Fields

Development of Quantitative Field Drainage Ability Evaluation Method Based on Monitored Soil Water Content of Converted Paddy Fields

Forecast flexural strength of pervious concrete by SVR

For the development of construction technology, pervious concrete is vastly using in road infrastructure. Pervious concrete has a strong drainage ability that can recharge groundwater, made by the coarse aggregate, water, and cement with little fine aggregate or without fine aggregate. The compressive and flexural strengths of pervious concrete are vital parameters to identify the concrete quality and also necessary in the process of analysis and design of a concrete infrastructure. This research represents a system for forecasting the flexural strength obtained from the compressive strength (0 up to 30 MPa) of concrete cube and cylinder types specimens by support vector regression (SVR) for both 7 and 28 days. Experimental data from various literature have been collected to formulate the model. It appears that the relationship between the compressive strength and flexural strength of pervious concrete is non-linear. The linear models developed with limited lab test found ineffective when they are subjected to wide range of data set for flexural strength prediction. In this study, all compared models and developing model’s effectiveness are examined based on R2, RMSE, MAPE, MSE, and IAE parameters for both 7- and 28-days specimens.

Randomized controlled trial on application of negative pressure materials of polyvinyl alcohol and polyurethane in full-thickness burn wounds after escharotomy

Randomized controlled trial on application of negative pressure materials of polyvinyl alcohol and polyurethane in full-thickness burn wounds after escharotomy

Evaluation of a novel biodegradable ureteral stent produced from polyurethane and magnesium alloys.

Indwelling ureteral stents represent a very frequently used procedure in urological clinical practice that ensures the drainage of urine from the upper urinary tract. However, the stents could result in many stent-associated complications, such as encrustation and patient discomfort. We developed a new type of biodegradable ureteral stents produced from degradable polyurethane and magnesium alloys. In the present study, we investigated the biocompatibility and the property of degradation of the biodegradable ureteral stents. We evaluated the cytotoxicity of biodegradable ureteral stent by the MTT assay in vitro. The rabbit dorsal muscle embedding test was used to assess the biocompatibility of the degradable stents. Inflammation and fibrosis of muscle tissue were noted to evaluate compatibility at 1, 2, 4, 6 weeks after stents implanted in muscle. The degradation of the biodegradable ureteral stents was assessed by measuring the weight loss of the samples in AUS (artificial urine solution). For validating the degradation property of degradable stents in vivo, we inserted a degradable stent or a conventional biostable stent into Bama pigs. Furthermore, blood studies, liver function tests, renal function tests, urine studies, and computerized tomography (CT) were performed postoperatively. Our study confirms that the degradable polyurethane-based biodegradable ureteral stent has good biocompatibility. Our biodegradable ureteral stents were completely degraded within 4 weeks and provided a better ability of drainage than conventional stents. They hold promise for decreasing the need for a secondary procedure and stent related morbidity, such as infections.

Field Test Study on Treatment of Dredged Soil with Cotton Straw

A new method for treatment of dredger fill was proposed to address its low bearing capacity, high consolidation cost, and long treatment duration. In this method, cotton straw is used as both the draining and reinforcement material. Specifically, cotton straw bundles are driven into the dredged soil and vacuum preloading is then performed. Subsequently, environmentally friendly grout is poured into the cotton straw bundles, and solidified vertical reinforcements are thus formed, allowing dredged soil to be treated. Design parameters for the cotton straw draining were obtained from previous laboratory test. Based on a real-world project, a field test was performed to study treatment of dredged soil through cotton straw drainage and reinforcement, and a comparison was drawn with the traditional cement mixing vertical reinforcement method. The vacuum degree, settlement, and water content of reinforced soil suggested a good ability of cotton straw drainage to solidify dredged soil. The static load test indicated that vertical reinforcement after grouting demonstrated better strength than cement reinforcements. This study provides new insights into the treatment of dredger fill and can broaden the application of cotton straw and also reduce environmental pollution caused by cotton straw burning.

Lymph node-targeted immune-activation mediated by imiquimod-loaded mesoporous polydopamine based-nanocarriers

Toll-like receptor (TLR) agonists are the potent stimulants of innate immune system and hold promises as an adjuvant for anticancer immunotherapy. Unfortunately, most of them are limited by a prompt dissemination, and thus caused “wasted inflammation”. Hence, how to restrict their action radius into lymphoid tissues is of great relevance to enhance their efficacy and concomitantly alleviates the side effects. Here, imiquimod (R837), a TLR 7 agonist, was loaded into mesoporous polydopamine (MPDA) nanocarriers with high efficiency. Moreover, its surface was modified by polyvinyl pyrrolidone (PVP) to enhance their lymphatic drainage ability. These nano-adjuvants have obvious advantages in promoting dendritic cell (DC) maturation in comparison to free R837. Moreover, their transportation and retention ability in proximal lymph nodes (LNs) were also confirmed, by which lymphatic drug exposure can be maximized to a great extent. Consequently, effective DC activation and CD8+ T cell responses were observed as expected by R837 released in draining LNs. This effect was further enhanced by the presence of endogenous tumor antigens from apoptosis debris induced by MPDA-based photothermal effect, and thus led to the growth inhibition of subcutaneous B16 melanomas. The results demonstrated the great potency against melanoma of the designed PVP-MPDA@R837 nano-adjuvants by combining photothermal conversion property of MPDA with lymphatic-focused immune-activation.

Enhancement of condensation heat transfer on a microstructured surface with wettability gradient

Micro- and nanoscale phase-change phenomena are becoming increasingly important for heat transfer owing to the rapid development of microelectromechanical system (MEMS) technology in the fields of microsystems such as in advanced electronics or biomedical devices. In particular, many studies on dropwise condensation have been conducted based on progress of material science for hydrophobic or hydrophilic surfaces. Although majority of these studies achieved high heat transfer performance under low subcooling conditions, the heat transfer coefficient decreased as subcooling increased because of condensate removal limitations. Our previous study using a bi-philic surface with microgrooved structures failed in terms of flooding wherein several patterns were covered by a large liquid film because of poor drainage ability. In microsystems, gravity or vapor shearing forces are ineffective in enhancing droplet departure from the condensing surface as the spaces of the microsystem are limited. Thus, to enhance condensation heat transfer, the flooding and plugging phenomena need to be considered, and therefore, a novel condensing surface needs to be fabricated to remove the growing droplets from the condensing surface. Herein, we introduced a wettability gradient by gradually changing the pattern widths of the hydrophobic and hydrophilic surfaces. The groove width of the hydrophilic part was designed to increase as the condensate flowed downstream. The experiments were conducted under low steam pressure conditions; we found that the size of the droplets could be controlled by modifying the pattern width and the wettability gradient could be used to remove large droplets. The flooding was suppressed, and the heat transfer coefficient was enhanced by three times compared with the results of the microstructured condensing surface with a straight pattern. These results showed that the wettability gradient effectively enhanced condensation heat transfer.

Effect of air mobility in a soil pipe on water flow through a model hillslope after pipe clogging

AbstractSoil pipes (continuous macropores expanding laterally in the soil subsurface) are a key factor controlling hillslope water cycles and sediment transport. Soil pipes usually enhance slope stability under rainfall events through their high water drainage ability, and pipe clogging by sediments is regarded as a risk for slope failure. In this study, we conducted a bench‐scale pipe clogging experiment to clarify the effect of air mobility in soil pipes on water flow and water pressure build‐up in the slope at the clogged point. Before pipe clogging, the soil pipe drained rainwater effectively and lowered the groundwater table. After the pipe clogging event, the mobility of air in the soil pipe before the clogging determined the water flow in the slope. When the air in the soil pipe connected to the atmosphere and moved freely, the water level in the soil pipe increased at the pipe clogging, and water pressure build‐up was limited near the pipe outlet. On the other hand, when air in the soil pipe was entrapped by the clogging, water pressure suddenly increased, and the groundwater table of the whole slope rose correspondingly. This study clearly demonstrated the importance of pipe morphology with respect to air connectivity between the pipe and atmosphere to elucidate the water flow and slope stability during the pipe clogging event. © 2019 John Wiley & Sons, Ltd.

ФОРМУВАННЯ ГІДРОГЕОЛОГО-МЕЛІОРАТИВНОЇ ОБСТАНОВКИ НА РИСОВИХ ЗРОШУВАЛЬНИХ СИСТЕМАХ ПРИДУНАВ'Я ТА ШЛЯХИ ПІДВИЩЕННЯ ЇХНЬОЇ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ З УРАХУВАННЯМ ПОГОДНО-КЛІМАТИЧНИХ РИЗИКІВ

The analysis of the main reasons for the unsatisfactory hydrogeological-reclamation state of the Danubian rice irrigation systems was carried out and the ways of its improvement due to the increase of drainage ability of irrigated lands of rice systems were considered. On the saline lands of the rice systems of the Danube delta drainage network is the main means of active and directed influence on the water-salt regime of the reclaimed area, formation of the regime of groundwater level, both in the growing season and in the not irrigated period for rice and attendant crops. Drainage network is essentially a determining factor in the formation of productivity of agricultural lands. An analysis of the efficiency of the drainage operation on the rice systems of the Danube Delta has shown that drainage built in accordance with the design standards that were in force at the time of construction does not provide uniform drainage ability in the area and the soil profile of rice fields. This is one of the main reasons for their unsatisfactory hydrogeological-reclamation state and reducing the yield of rice and attendant crops. By conducting optimization calculations according to the expense indicator, taking into account that optimal vertical filtration rate for the Danubian rice irrigation systems is at the level of 6...8 mm/day the optimal distance between the drains – 100 m was determined. Constructive improvement of existing rice systems with the drainage network in the form of open drains and distances between them – 250...500 m can be accomplished through the installation of additional separate closed drain-collectors. These drain-collectors are appropriate to arrange along the checks, with the set distance. For reducing the value of the vertical filtration rate in the drainage zone where it reaches 25 mm/day it is advisable to practice maintaining of water levels in the drainage network. Consequently, it is possible to achieve a reduction of the filtration rate to 4…5 mm/day. Developed measures and corresponding reconstruction of rice systems will enable to maintenance of satisfactory hydrological and hydrogeological regimes,ensure uniform salinity of soils during the cultivation of flooded rice, create favorable conditions for oxidation-reducing processes and maintenance of favorable ecological-reclamation state on the system.

Intracranial lymphatic drainage discharges iron from the ventricles and reduce the occurrence of chronic hydrocephalus after intraventricular hemorrhage in rats

Background: The discovery of intracranial lymphatic system provides a new theory about cerebrospinal fluid circulation. In order to investigate the role of lymphatic drainage in hydrocephalus after intraventricular hemorrhage (IVH), three parts of experiments were performed.Methods: IVH model was produced by 200ul autologous blood injection into lateral ventricle of SD male rats. Perls Prussian blue reaction was used to confirm the ability of iron drainage through deep cervical lymph nodes (DCLNs) in part I. The part II measured the volume of ventricles by MR scanner , and the part III compared the ferritin level of area surrounding ventricles by Western blotting after IVH.Results: The ability of iron drainage through DCLNs was confirmed. DCLNs-excised rats got a 19.6% higher incidence of hydrocephalus than DCLNs-preserved rats at day 28 after IVH. And DCLNs-excised group showed higher ferritin level than DCLNs-preserved group at day 3 after IVH.Conclusion: The whole experiments revealed the role of intracranial lymphatic system in discharging iron out of central nervous system at acute phase of IVH, and proved the function in alleviating and avoiding hydrocephalus at chronic phase after IVH.

Analysis by numerical experiments of desalinization of a salt-affected paddy field using a rice husk underdrainage system

In a monsoon climate, salt accumulates not only in drylands, but also in paddy fields during the dry season. Because natural desalinization by gravitational drainage is very difficult in paddy fields, drainage facilities are needed to remove salts from affected paddy fields. A rice husk underdrainage system (RHUS) is one applicable method. Although this system is simple and reasonable, there is an unfortunate lack of available information for its practical realization. In this study, we conducted numerical field-scale experiments with an RHUS using HYDRUS 2D/3D software to obtain information for designing such a system. Our results clarified the effect of outlet size, rice husk drain (RHD) width, and RHD gradient on the amount of discharged soil water/salts and saline water movement in the paddy field. We summarized our results as follows: (1) outlet size did not affect the system’s drainage ability; (2) small-width RHD discharged saline soil water at a greater rate than large-width RHD when using the same amount of leaching water; (3) because the RHD worked as a bypass of saline water movement from the plow layer to the lower soil layer, the amount of saline water removed from the plow layer was larger with the large-width RHD than with the small-width RHD; and (4) the large gradient of the RHD was advantageous in increasing the amount of discharged saline soil water, but the effect was small, so it appears unnecessary for practical application.

Electrospun Twin Fibers Encumbered with Intrinsic Antioxidant Activity as Prospective Bandage

Our investigation for the first time explores the possibility of fabrication of a Capsaicin/polyurethane-based bioactive wound dressing. A micro/nanofibrous bandage was synthesized by electrospinning polyurethane supplemented with natural anti-inflammatory agent, Capsaicin. Herein, the best concentration (3%) of Capsaicin in polyurethane to get a consistent solution was standardized in order to acquire the composite micro/nanofibrous dressing. The as-spun bandage has been investigated by scanning electron microscopy and Fourier transform infrared spectroscopy, and biocompatibility of muscle cells on the bioactive bandage was also examined. Free radical scavenging activity of the fabricated micro/nanofiber bandage was estimated using 2,2-diphenyl-1-picrylhydrazyl assay. Inclusion of Capsaicin in polyurethane transformed the morphology as well as dimension of the fibers. Anti-oxidant wound bandage with diameters around 150–500 nm was fabricated by physical unification of polyurethane with natural Capsaicin. Here, polyurethane was used as a foundation polymer, which was blended with Capsaicin to attain desirable characteristics such as better anti-oxidant activity, hydrophilicity and excellent cell attachment. The polyurethane wound bandage possesses enlarged surface, proscribed evaporation, and fluid drainage ability. These results suggest the beneficial influence of antioxidant Capsaicin on wound repairing process. Therefore, a biologically active, natural compounds such as Capsaicin is material of choice for fabrication of future wound dressings.

A novel Lawsonia inermis (Henna)/(hydroxyethylcellulose/polyvinylpyrrolidone) wound dressing hydrogel: radiation synthesis, characterization and biological evaluation

A traditional plant extract from Lawsonia inermis (Henna) with proven antimicrobial properties had been used for the preparation of (hydroxyethylcellulose/polyvinylpyrrolidone) hydrogel dressing using gamma irradiation for crosslinking and sterilization techniques. Henna dressings were characterized by studying the effect of Henna incorporation on the gel fraction, swelling degree, the morphological features using scanning electron microscopy, fluid drainage ability using pseudo-extracellular body fluids and the bioadhesion characteristics. It was found that, at the time the increment of Henna content slightly decreased the gel fraction, it improves the swelling degree. Scanning electron micrograph showed an adequate porous structure which is an essential criterion to be an ideal wound dressing. The bioadhesion evaluation showed an adequate adhesion performance as well as ease of removal. The microbial penetration test against Staphylococcus aureus and Escherichia coli revealed that Henna dressing is not only a good barrier for bacterial penetration but also it prevents its growth. In vitro cytotoxicity and haemolytic potency evaluation of Henna dressing substantiate its biocompatibility.