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Suharyatun, Siti, Bambang Purwantana, Abdul Rozaq, and Muhjidin Mawardi. "THE CLAY CONTENT EFFECT ON THE FORMATION OF SHALLOW MOLE DRAINAGE AND THE RATE OF LOWERING SOIL MOISTURE CONTENT." Jurnal Agritech 34, no. 03 (October 24, 2014): 347. http://dx.doi.org/10.22146/agritech.9464.
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Installing shallow mole drainage in the soil is infl uenced by various factors, namely; the physical properties of soil and tools which are used. One of the physical properties of soil that infl uences the formation of the mole drainage is the clay content of soil. This study aimed to explore the condition of the mole drainage formed in paddy soil with different clay contents. The study was conducted in a laboratory scale using a soil bin, a model of mole plough, and soil which was kept homogeneous in the boxes. The experiment was conducted at the Laboratory for Energy andAgricultural Engineering, Agricultural Engineering Department, Universitas Gadjah Mada, Yogyakarta. Mole drainage was installed in 3 paddy soils with different clay content, namely; 13.12% (soil A; loam soil), 41.17% (soil B; clay soil) and 53.36% (soil C; clay soil). The study was conducted by analyzing the geometry of the mole drainage and observingthe soil deformation which occurred due to the formation of the mole drainage. The study showed that perfect mole drainages were installed in all of those three types of soil. The mole drainages were quite good and stable with little cracks. Based on the soil crack and fi ssuring of soil, the largest soil deformation has occurred in soil with the highestclay content and the smallest one in soil with the lowest clay content. The characteristics of those three installed mole drainages were almost the same, but they had different effect on the rate of lowering soil moisture content. Here, the mole drainage installed in loam soil is different from which of installed in clay soil. The mole drainage installed in theloam soil did not infl uence the rate of lowering soil moisture content. Contrary, the mole drainage installed in clay soil has effected to increase the rate of lowering soil moisture content.Keywords: Mole drainage, soil moisture content, clay content
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Matjakriandi, Matjakriandi, Alfiansyah Yulianur, and Muhammad Isya. "EVALUASI DRAINASE JALAN PONDOK BARU – PERMATA KABUPATEN BENER MERIAH KM. 4+200 SAMPAI DENGAN KM. 10+522." Jurnal Teknik Sipil 1, no. 4 (February 28, 2018): 929–40. http://dx.doi.org/10.24815/jts.v1i4.10054.
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Abstract: The road is a transportation infrastructure that is essential for humans. The road connects a community of people in a region with other regions, one important aspect for highway construction was securing the road from the water, either from rain or from a side-street drainage impact on the road surface damage. Bener Meriah district, a mountainous region with an altitude of 100 meters above sea level up to 2,500 meters, with a fairly high rainfall. Road conditions on the slopes and foothills affect the slope of the road longitudinal slope and drainage in the rainy season the road so much going drainage is not functioning properly. Water flows and puddles on the pavement as well as the water flows out of the drainage caused by slope which was great so happens scouring the drainage, plus more water falling from the slopes directly to the pavement without any treatment, for it was necessary to do research that aims to identify capacity of the existing road drainage network, knowing and planning network capacity as well as the road drainage slope drainage is needed so that the roads are not inundated by rain water discharge. The research was conducted on roads Pondok Baru - Permata on Sta.4 + 200 s / d Sta10 + 522. The method used in this research was the average algebra as well as to get a discharge plan and dimension using numerical equations rational modification with a system of trial and error, to come to the rain plan period of 5 years is 184 mm. Existing drainage conditions based on calculations obtained an average drainage discharge 1.52 m3 / sec and the discharge count 0.52 m3 / sec flow rate of water drainage on average at 7.54 m / sec speeds exceeding 1.5 license m / sec. Having calculated back then obtained an average discharge chute 0.519 m3 / sec and the discharge count 0,517 m3 / sec at the speed of average water flow of 1.31 m / sec, drainage on roads Pondok Baru - Permata diredesign necessary. Abstrak: Jalan merupakan infrastruktur transportasi yang sangat penting bagi manusia. Jalan menghubungkan suatu komunitas masyarakat di suatu wilayah dengan wilayah lain, salah satu aspek penting untuk konstruksi jalan raya adalah mengamankan jalan dari air, baik dari air hujan maupun dari drainase samping jalan yang berdampak terhadap kerusakan permukaan jalan. Kabupaten Bener Meriah merupakan daerah pegunungan dengan ketinggian dari permukaan laut 100 meter sampai dengan 2.500 meter, dengan curah hujan yang cukup tinggi. Kondisi jalan yang berada di lereng dan kaki gunung mempengaruhi terhadap kemiringan memanjang jalan dan kemiringan drainase jalan sehingga pada musim hujan banyak terjadi drainase tidak berfungsi dengan baik. Air mengalir dan tergenang di perkerasan jalan serta air mengalir dengan cepat pada drainase yang disebabkan oleh slope yang besar sehingga terjadi gerusan pada drainase, ditambah lagi air jatuh dari lereng langsung ke perkerasan jalan tanpa ada penanganan, untuk hal itu perlu dilakukan penelitian yang bertujuan untuk mengidentifikasi kapasitas jaringan drainase jalan yang ada, mengetahui dan merencanakan kapasitas jaringan drainase jalan serta drainase lereng yang dibutuhkan agar jalan tidak tergenang oleh debit air hujan. Penelitian ini di lakukan pada ruas jalan Pondok Baru – Permata pada Sta.4+200 s/d Sta10+522. Metode yang dipakai dalam penelitian ini adalah metode rata-rata aljabar serta untuk mendapatkan debit rencana dan dimensi menggunakan metode rasional modifikasi persamaan numeris dengan sistem trial and error, didapat untuk hujan rencana periode 5 tahun yaitu 184 mm. Kondisi drainase eksisting berdasarkan perhitungan didapat debit drainase rata-rata QS 1,52 m3/detik dan debit hitung QT 0,52 m3/detik dengan kecepatan aliran air rata-rata pada drainase 7,54 m/detik yang melebihi kecepatan izin 1,5 m/detik. Setelah dihitung kembali maka didapatkan debit saluran rata-rata QS 0,519 m3/detik dan debit hitung QT 0,517 m3/det dengan kecepatan aliran air rata-rata 1,31 m/detik, drainase pada ruas jalan Pondok Baru – Permata perlu dilakukan desain.
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Saadat, Samaneh, Laura Bowling, Jane Frankenberger, and Kyle Brooks. "Effects of Controlled Drainage on Water Table Recession Rate." Transactions of the ASABE 60, no. 3 (2017): 813–21. http://dx.doi.org/10.13031/trans.11922.
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Abstract. Controlled drainage is a best management practice that decreases nitrate loads from subsurface drainage, but questions remain about optimal operation strategies. One unanswered question is whether the outlet should be lowered prior to or directly after a rainfall event to reduce the amount of time that the water table is at a level that would be detrimental to either trafficability or crop yield. The objective of this study was to determine how much controlled drainage lengthens the time needed for the water table to fall after a rainfall event, to inform possible improvement in the management of controlled drainage systems. This objective was addressed using water table recession rates from two pairs of controlled and free-draining fields located at the Davis Purdue Agricultural Center in Indiana over a period of nine years (2006-2014). At each pair, comparison of mean recession rates from the two fields indicated that controlled drainage reduced recession rate. The significance of the relationship between paired observations and the effect of controlled drainage was determined by a paired watershed approach using analysis of variance (ANOVA) and covariance (ANCOVA). Raising the outlet of the subsurface drainage system decreased the mean rate of water table recession by 29% to 62%, increasing the time needed for the water table level to fall from the surface to 30 and 60 cm depths by approximately 12 to 26 h and 24 to 53 h, respectively. Based on these results, it can be concluded that lowering the outlet before storm events would reduce the amount of time that the water table is at a detrimental level for either crop growth or trafficability. However, the trade-off between costs and benefits of active management depends on the sensitivity of the crop and probability of a severe storm. Keywords: Drainage water management, Managed drainage, Paired watershed approach, Tile drainage, Water table drawdown.
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Sahlin, Sven, Carl-Gustaf Laurell, Enping Chen, and Bo Philipson. "Lacrimal drainage capacity, age and blink rate." Orbit 17, no. 3 (January 1998): 155–59. http://dx.doi.org/10.1076/orbi.17.3.155.2757.
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SAHLIN, SVEN, and ENPING CHEN. "Gravity, Blink Rate, and Lacrimal Drainage Capacity." American Journal of Ophthalmology 124, no. 6 (December 1997): 758–64. http://dx.doi.org/10.1016/s0002-9394(14)71692-7.
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Kaupuža, Renāte, and Gotfrīds Noviks. "DETERMINATION OF HABITAT 6270*_3 PERMITTED DRAINAGE RATE." HUMAN. ENVIRONMENT. TECHNOLOGIES. Proceedings of the Students International Scientific and Practical Conference, no. 23 (April 24, 2019): 122. http://dx.doi.org/10.17770/het2019.23.4403.
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Amelioration has dramatically altered the distribution of semi-natural grasslands in Latvia and as a result of the drainage, and the ocurrance of humid grassland habitats has decreased sharply. The aim of the paper was to identify drainage rate for habitat 6270*_3 ecohydrological requirements which is necessary for its successful management and long-term existence. The work looked at 15 equally managed (extensively grazed and/or mowed) perennial, natural grasslands at different levels of drainage resulting in various quality states. To reveal the most habitat-preserving drainage rate, for each site of the habitat 6270*_3 a decrease of groundwater table was identified. As a result a rate that meets ecohydrological requiremets is procured.
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Levytska, V., and P. Khoruzhiy. "INFLUENCE OF DRAINAGE WELLS IN ANTIFILTRATION DRAINAGE SYSTEM." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 3 (90) (2020): 91–96. http://dx.doi.org/10.17721/1728-2713.90.13.
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The decrease of water levels in the drainage wells of the coastal anti-filtration drainage system with the siphon method of water intake from them was analyzed. The interaction of water-lowering wells with different depths and located at variable distances from each other is considered, which makes it possible to ensure uniform drainage from each well and to achieve a steady decrease in the level of groundwater over the entire length of the antifiltration drainage system.The results of the performed analytical studies are presented. The example of the Kamyanka-Dniprovska's anti-filtration drainage system shows that the decrease in water levels in wells at the same flow rate of pumped water depends on their hydraulic interaction, hydrogeological conditions of water filtration from the aquifer and the distance of the antifiltration drainage system from the bank-side. The results obtained indicate that the highest level of water depletion of the coastal vertical anti-filtration drainage system line with siphon drainage from wells is achieved at a distance of a number of wells from the Kakhovsky reservoir bank-side a = 100 m, at the same water flow rate from each of the drainage wells (Q = 604,8 m3 /day), located at different distances from each other. The highest rate of additional reduction of water obtained through mutual hydraulic action was obtained in the 7th well, which has a depth of 14,9 m, and it is located at a distance of 100 m from the 6th well and at a distance of 110 m from the 8th well. The lowest indicator of the level of groundwater reductions at different indicators of the distance of a number of drainage wells to the bank-side a (30, 50, 80, 100 m) is observed in the first well, farthest from the water collection well.
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David Suits, L., TC Sheahan, TH Seah, and T. Juirnarongrit. "Constant Rate of Strain Consolidation with Radial Drainage." Geotechnical Testing Journal 26, no. 4 (2003): 10173. http://dx.doi.org/10.1520/gtj11251j.
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Criddle, Richard S., Thimmappa S. Anekonda, Sharon Tong, John N. Church, F. Thomas Ledig, and Lee D. Hansen. "Effects of climate on growth traits of river red gum are determined by respiration parameters." Functional Plant Biology 27, no. 5 (2000): 435. http://dx.doi.org/10.1071/pp98057.
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Temperature is the major uncontrollable climate variable in plantation forestry. Matching plants to climate is essential for optimizing growth. Matching is usually done with field trials because of the lack of a predictive relation between laboratory measurements of physiological responses and climatic factors affecting growth. This paper evaluates the potential of using respiration parameters for selection of appropriate drainage or seed sources within a drainage for superior growth in a particular climate. The growth traits measured are tree height, stem diameter and stem volume. The respiratory parameters measured are respiratory heat rate, rate of CO2 production, and temperature dependence of respiratory heat rate. Five open-pollinated families from each of nine seed sources of river red gum (Eucalyptus camaldulensis Dehnh.) were studied following selection from a larger set of seed sources planted at three plantations in California. The three plantations differ in climate, particularly in extreme temperatures, diurnal temperature variability and total rainfall. Within each plantation, growth and respiration parameters show high genetic variation [overall coefficient of variation (CV) = 14–58%, family CV = 11–33%], with at least one of these traits showing significant (P < 0.10) difference due to drainage, or source within drainage, or families within source. The relationship of growth to respiration for each trait differs, depending on testplantation, origin drainage, source or family, suggesting a unique pattern for each trait. Correlation of drainage level averages between growth and respiration were strongly negative and significant (P = 0.10–0.01). Rankings for drainages between paired plantations were strong and significant (P = 0.10–0.05) only for respiration, but not for growth traits.
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Jiao, Pingjin, Yingduo Yu, and Di Xu. "Effect of Drainage Water Reuse on Supplementary Irrigation and Drainage Reduction." Transactions of the ASABE 61, no. 5 (2018): 1619–26. http://dx.doi.org/10.13031/trans.12697.
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Drainage water reuse has the potential to supplement irrigation, reduce drainage, and alleviate the area source pollution caused by agricultural drainage. This study aimed to evaluate the effects of influencing factors of drainage water reuse on supplementary irrigation and drainage reduction rates. To evaluate the effects, a water balance model was constructed to describe the irrigation water requirement and drainage water storage of a pond. The irrigation water requirement was calculated using the Penman-Monteith equation and the crop coefficient method while considering field leakage and effective rainfall; the drainage water volume was calculated using the improved Soil Conservation Service (SCS) model. The model was applied to the rice planting area in the Zhanghe Reservoir Irrigation District. Simulation results show that the supplementary irrigation and drainage reduction rates are primarily affected by the ratio of irrigation to drainage areas (RID), the pond volume ratio (PV), and the initial storage ratio (PSi); interactions among the three parameters are also observed. The RID, PV, and PSi contribute approximately 4:3:1 to the average variations in the supplementary irrigation rate. The supplementary irrigation rate increases with the values of PV and PSi but decreases with the increases of RID. For the drainage reduction rate variation, the average contribution percentages of PV and RID are 70% and 10%, respectively. Increasing PV and RID or reducing PSi enhances the drainage reduction rate. Adjusting the combination of parameters PV and RID can simultaneously maximize the supplementary irrigation and drainage reduction rates. Keywords: Drainage reduction, Drainage water reuse, Pond, Supplementary irrigation, Water balance model.
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Ghorbani, Karim, Aimrun Wayayok, Masumeh Abbaszadeh, and Ahmad Fikri. "The effect of pipe collectors in reducing the drainage coefficient rate." Water Supply 15, no. 4 (February 4, 2015): 675–82. http://dx.doi.org/10.2166/ws.2015.014.
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A high groundwater table and soil salinity, especially in arid regions, often cause serious problems for agriculture. In irrigated areas the subsurface drainage can be an effective technique to lower the depth of the groundwater table and reduce soil salinity. In drainage systems, lateral pipes are designed to collect the free water from soil and convey it into collectors. In other words, collectors are commonly designed to convey drainage water from laterals downstream, while the laterals play an additional role in removing excess water from irrigated land. The present research was conducted to investigate the effects of collectors in discharging excess water from soil using a laboratory-tank model. The results indicated that on average 24% of drainage water was directly discharged through the collector pipe when the hydraulic gradient of the flow was sloped toward the collector pipe. Hence, it was concluded that, with proper monitoring, collectors were capable of reducing the drainage coefficient from an average of 32.5 to 24.5 mm/day, while drain spacing of the laterals can increase the results by about 15% in comparison with the present situation.
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Thrinch, Nhi, and Honh Thung. "The Effect of Variations in Drainage on Infiltration Rates in Pore Cylindrical Drainage." Journal La Multiapp 2, no. 3 (August 12, 2021): 33–39. http://dx.doi.org/10.37899/journallamultiapp.v2i3.393.
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Inundation and floods are caused by a combination of factors including lower rain catchment areas, decreasing infiltration rates, and an uneven distribution of rainfall throughout the year, which all combine to create flooding and inundation issues. The alternative option is to install an efficient drainage system that is ecologically friendly, since in addition to its role of accommodating and draining water, it also has the additional purpose of absorbing water into the subsurface soil layer. A pore hole is created at the bottom of the drainage channel in order for the water to be absorbed. There was a desire to investigate the impact of soil texture on the rate of infiltration, therefore this research was conducted. Three kinds of soil were utilized as infiltration medium, namely sandy loam, loam, and clayey loam, all of which were found in the surrounding area. In addition, there are three variants of hole spacing, namely 16 cm, 32 cm, and 48 cm, as well as three variations of flow rate, namely 400 cm3/s, 1500 cm3/s, and 2500 cm3/s, among others. As a consequence of laboratory studies, it has been shown that the impact of changes in flow rate on infiltration discharge is inversely proportional to the flow rate, i.e., the higher the flow rate, the smaller the infiltration discharge that occurs. The reason for this is because it is influenced by the flow velocity
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Skaggs, R. Wayne. "Coefficients for Quantifying Subsurface Drainage Rates." Applied Engineering in Agriculture 33, no. 6 (2017): 793–99. http://dx.doi.org/10.13031/aea.12302.
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Abstract. It is proposed that technical papers on drainage research studies and engineered design projects should report standard coefficients or parameters that characterize the hydraulics of the system. The following coefficients define key subsurface drainage rates that can be used to quantify and compare the hydraulics of drainage systems across sites, soils and geographic locations. (1) The steady subsurface drainage rate (cm/d) corresponding to a saturated profile with a ponded surface. This subsurface drainage rate defines the length of time that water remains ponded on the soil surface following large rainfall events. It is proposed that this rate be called the Kirkham Coefficient (KC) in honor of Professor Don Kirkham who derived analytical solutions for saturated drained profiles for most soil and boundary conditions of interest. (2) Drainage intensity (DI), which represents the drainage rate (cm/d) when the water table midway between parallel drains is coincident with the surface. The DI can be estimated by the Hooghoudt equation and is dependent on the effective saturated hydraulic conductivity of the profile, drain depth, spacing, and depth of the soil profile or restrictive layer. (3) The drainage coefficient (DC), which quantifies the hydraulic capacity of the system. This value is the rate (cm/d) that the outlet works can remove water from the site. It is dependent on the size, slope, and hydraulic roughness of the laterals, submains, mains, and, in cases where pumped outlets are used, the pumping capacity. Routine inclusion of these three coefficients in the documentation of research and design projects would facilitate comparison of results from different soils and drainage systems, and generally, the meta-analysis of data pertaining to drainage studies. Keywords: Drainage, Drainage intensity, Drainage coefficient, Drainage nomenclature, Kirkham Coefficient.
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Miyasaka, Yoshio, Kenzoh Yada, Takashi Ohwada, Takao Kitahara, Akira Kurata, and Katsumi Irikura. "An analysis of the venous drainage system as a factor in hemorrhage from arteriovenous malformations." Journal of Neurosurgery 76, no. 2 (February 1992): 239–43. http://dx.doi.org/10.3171/jns.1992.76.2.0239.
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✓ The authors studied the venous drainage system and its impairment in relation to risk of hemorrhage in 108 cases of supratentorial arteriovenous malformation (AVM). The proportion of AVM's undergoing hemorrhage (hemorrhagic rate) was calculated in relation to: 1) the number of draining veins (one, two, or three or more); 2) the presence or absence of impairment in venous drainage (severe stenosis or occlusion in draining veins); and 3) the location of draining veins (deep venous drainage alone, superficial venous drainage alone, or a combination of the two). Statistical analysis demonstrated that AVM's with the following characteristics had a high risk of hemorrhage: 1) one draining vein (hemorrhagic rate 89% in 54 patients); 2) severely impaired venous drainage (hemorrhagic rate 94% in 18 patients); and 3) deep venous drainage alone (hemorrhagic rate 94% in 32 patients). The present study suggests that the venous drainage system of AVM's is significantly associated with the risk of hemorrhage of these lesions. Therefore, careful preoperative angiographic evaluation of the venous drainage system is mandatory for decision making in the management of patients with AVM's.
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Hu, Qiujia, Shiqi Liu, Shuxun Sang, Huihuang Fang, Ashutosh Tripathy, Ling Yan, Mengfu Qin, and Chonghao Mao. "Numerical analysis of drainage rate for multilayer drainage coalbed methane well group in Southern Qinshui basin." Energy Exploration & Exploitation 38, no. 5 (August 6, 2020): 1535–58. http://dx.doi.org/10.1177/0144598720946494.
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Multilayer drainage is one of the important technologies for coalbed methane (CBM) production in China. In this study, a multi-field fully coupled mathematical model for CBM production was established to analyze the multilayer drainage of CBM well group in southern Qinshui basin. Based on the numerical simulation results, the characteristics of CBM well production under different drainage rates and key factors influencing the CBM production were further discussed. The results show that the effect of an increased drainage rate on gas production of CBM wells and CBM recovery of No.3 coal seam is not significant. However, it significantly improved the gas production of CBM wells and CBM recovery of No.15 coal seam. After a long period of production, the CBM content in No.3 coal seam has reduced to a low level and the pressure drop potential of No.3 coal seam is insignificant, which are important reasons for the insignificant increase of CBM production even under a drainage rate of 2 to 7 times. Conversely, No.15 coal seam has larger residual CBM content and increasing the drainage rate can significantly improve the pressure drop and superimposed well interference of No.15 coal seam, which means No.15 coal seam has greater production potential than No.3 coal seam. Therefore, it is recommended to improve the gas production and CBM recovery in No.15 coal seam by increasing the drainage rate, and the average hydraulic pressure drop should be 0.018–0.031 MPa/day. The influence of effective stress is weak in No.3 and No.15 coal seam, and the coal seam permeability is largely influenced by the shrinkage of coal matrix caused by CBM desorption. This indicates the feasibility of increase in gas production from CBM wells by increasing the drainage rate.
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Cokar, M., M. S. S. Kallos, and I. D. D. Gates. "A New Thermogeomechanical Theory for Gravity Drainage in Steam-Assisted Gravity Drainage." SPE Journal 18, no. 04 (April 22, 2013): 736–42. http://dx.doi.org/10.2118/163136-pa.
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Summary Oil-sands reservoirs in western Canada hold more than 170 billion bbl of recoverable heavy oil and bitumen representing a significant source of unconventional oil. At in-situ conditions, the majority of this oil has essentially no initial mobility because of its high viscosity, which is typically in the hundreds of thousands to millions of centipoises. In steam-assisted gravity drainage (SAGD), steam injected into the formation heats oil at the edge of a depletion chamber, thus raising the mobility, ko/μo, of bitumen. Three main effects account for the increase of oil mobility. First, bitumen at steam temperature has viscosity typically less than 20 cp. Second, it is believed that shear, which is caused by thermal-expansion gradients, dilates the oil sand and causes enhanced permeability. Third, dilation at the chamber edge leads to smaller residual oil saturation (ROS). Because the production rate of SAGD is directly tied to the drainage rate of mobilized oil at the chamber edge, the thermogeomechanics of the oil sand at the chamber edge is a control on the performance of SAGD. In this study, a novel SAGD formula is derived that accounts for thermogeomechanical effects at the edge of the chamber. This paper couples dilation effects arising from thermal expansion into an analytical model for SAGD oil rate. The results reveal that volumetric expansion at the edge of the chamber plays a significant role in enabling effective drainage of bitumen to the production well.
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Coale, F. J., F. T. Izuno, and A. B. Bottcher. "Phosphorus in Drainage Water from Sugarcane in the Everglades Agricultural Area as Affected by Drainage Rate." Journal of Environmental Quality 23, no. 1 (January 1994): 121–26. http://dx.doi.org/10.2134/jeq1994.00472425002300010019x.
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Fang, Q. X., R. W. Malone, L. Ma, D. B. Jaynes, K. R. Thorp, T. R. Green, and L. R. Ahuja. "Modeling the effects of controlled drainage, N rate and weather on nitrate loss to subsurface drainage." Agricultural Water Management 103 (January 2012): 150–61. http://dx.doi.org/10.1016/j.agwat.2011.11.006.
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Bell, M. J., B. J. Bridge, G. R. Harch, and D. N. Orange. "Rapid internal drainage rates in Ferrosols." Soil Research 43, no. 4 (2005): 443. http://dx.doi.org/10.1071/sr04063.
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Adoption of conservation tillage practices on Red Ferrosol soils in the inland Burnett area of south-east Queensland has been shown to reduce runoff and subsequent soil erosion. However, improved infiltration resulting from these measures has not improved crop performance and there are suggestions of increased loss of soil water via deep drainage. This paper reports data monitoring soil water under real and artificial rainfall events in commercial fields and long-term tillage experiments, and uses the data to explore the rate and mechanisms of deep drainage in this soil type. Soils were characterised by large drainable porosities (≥0.10 m3/m3) in all parts of the profile to depths of 1.50 m, with drainable porosity similar to available water content (AWC) at 0.25 and 0.75 m, but >60% higher than AWC at 1.50 m. Hydraulic conductivity immediately below the tilled layer in both continuously cropped soils and those after a ley pasture phase was shown to decline with increasing soil moisture content, although the rate of decline was much greater in continuously cropped soil. At moisture contents approaching the drained upper limit (pore water pressure = –100 cm H2O), estimates of saturated hydraulic conductivity after a ley pasture were 3–5 times greater than in continuously cropped soil, suggesting much greater rates of deep drainage in the former when soils are moist. Hydraulic tensiometers and fringe capacitance sensors monitored during real and artificial rainfall events showed evidence of soils approaching saturation in the surface layers (top 0.30–0.40 m), but there was no evidence of soil moistures exceeding the drained upper limit (i.e. pore water pressures ≤ –100 cm H2O) in deeper layers. Recovery of applied soil water within the top 1.00–1.20 m of the profile during or immediately after rainfall events declined as the starting profile moisture content increased. These effects were consistent with very rapid rates of internal drainage. Sensors deeper in the profile were unable to detect this drainage due to either non-uniformity of conducting macropores (ie. bypass flow) or unsaturated conductivities in deeper layers that far exceed the saturated hydraulic conductivity of the infiltration throttle at the bottom of the cultivated layer. Large increases in unsaturated hydraulic conductivities are likely with only small increases in water content above the drained upper limit. Further studies with drainage lysimeters and large banks of hydraulic tensiometers are planned to quantify drainage risk in these soil types.
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Rusdiansyah, Rusdiansyah. "PENGARUH ADANYA MATERIAL BERPORI TERHADAP KARAKTERISTIK KONSOLIDASI TANAH LEMPUNG LUNAK LAHAN BASAH." Jurnal Kacapuri : Jurnal Keilmuan Teknik Sipil 1, no. 2 (December 1, 2018): 127. http://dx.doi.org/10.31602/jk.v1i2.1788.
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Salah satu cara untuk mempercepat aliran air maupun laju konsolidasi tanah lempung lunak lahan basah yaitu dengan menambahkan material porous didalam tanah maupun menggunakan drainasi vertical. Selama ini telah berkembang teknologi percepatan konsolidasi dengan vertical drain berbahan geosintetis. Selain berbahan geosintetis, bahan lainnya untuk material vertical drain masih terus dikembangkan untuk mencari keandalan yang ekonomis.Adapun yang menjadi permasalahan dalam penelitian ini adalah bagaimana derajat konsolidasi yang dihasilkan dari hasil pengujian konsolidasi tanah lempung lunak lahan basah yang ditambahkan adanya material berpori (berbahan pasir, sekam padi, dan arang kayu). Selain itu juga bagaimana pengaruh drainase (material berpori) radial, n (perbandingan diameter benda uji dan diameter drainase (material berpori)dari masing-masing material berpori.Dalam penelitian ini dilakukan uji konsolidasi dengan benda uji menggunakan tanah lempung lunak lahan basah. Pada bagian tengah benda uji diberi lubang berdiameter 0,75cm, 1cm, dan 1,5cm, kemudian ditambahkan material berpori berbahan pengisi berupa pasir, sekam padi, dan arang. Dari ketiga material berpori tersebut, selanjutnya akan dibandingkan sesamanya terkait kinerja material berpori sebagai sistem drainase (material berpori) didalam tanah. Hasil penelitian menunjukkan bahwa material sekam padi, pasir, dan arang dapat digunakan sebagai bahan drainase (material berpori) untuk tanah yang berkonsolidasi karena mampu meningkatkan nilai derajat konsolidasi (U%).Apabila ditinjau pada satu satuan waktu maka untuk jenis material drainase (material berpori)) berbahan sekam dapat menghasilkan derajat konsolidasi yang lebih besar dibandingkan material drainase (material berpori) berbahan pasir maupun arang.Material drainase (material berpori) berbahan sekam dapat menghasilkan nilai koefisien konsolidasi (Cv), nilai koefisien permeabilitas (k), dan nilai koefisien perubahan volume (mv) yang lebih besar dibandingkan dengan material drainase (material berpori) berbahan pasir dan arang.Nilai koefisien konsolidasi (Cv) semakin meningkat seiring dengan peningkatan nilai rasio diameter (n) hingga mencapai rasio diameter yang optimum (nopt), selanjutnya sesudah nilai rasio diameter optimum tercapai maka koefisien konsolidasi akan mengalami penurunan. Rasio diameter optimum pada tanah lempung lunak yang berkonsolidasi didapat pada nilai 6(enam).Kata kunci : Konsolidasi tanah, drainase (material berpori) vertical,derajat konsolidasi,koefisien permeabilitas, koefisien konsolidasi dan tanah lempung lunak lahan basah.One way to accelerate water flow and the rate of consolidation of wetland soft clay soil is by adding porous material in the soil and using vertical drainage. So far there has been a development of consolidation acceleration technology with a vertical drain made from geosynthetics. Apart from geosynthetics, other materials for vertical drain material are still being developed to find economical reliability. The problem in this research is how the degree of consolidation resulting from the consolidation test of wetland soft clay soil is added by the presence of porous material (made from sand, rice husk, and wood charcoal). In addition, also the effect of radial drainage (porous material), n (comparison of the diameter of the specimen and drainage diameter (porous material) of each porous material. In this study a consolidation test was carried out with specimens using soft soil wetlands. the center of the specimen was given a hole with a diameter of 0.75cm, 1cm, and 1.5cm, then added porous material made from fillers in the form of sand, rice husk, and charcoal. porous material) in the soil The results showed that rice husk, sand and charcoal material can be used as drainage material (porous material) for the soil that consolidates because it can increase the value of the consolidation degree (U%). for the type of drainage material (porous material) made from chaff can produce console degrees idasi which is bigger than drainage material (porous material) made from sand or charcoal. Drainage material (porous material) made from chaff can produce consolidated coefficient values (Cv), permeability coefficient value (k), and volume change coefficient value (mv) which is greater than the drainage material (porous material) made from sand and charcoal. The value of the consolidation coefficient (Cv) increases along with the increase in the diameter ratio (n) until it reaches the optimum diameter ratio (nopt), then after the optimum diameter ratio value is reached, the coefficient of consolidation will decrease. The optimum diameter ratio in soft clay that consolidates is obtained at a value of 6 (six). Keywords: Soil consolidation, vertical drainage (porous material), degree of consolidation, permeability coefficient, consolidation coefficient, and wetland soft clay soil.
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Song, Youngseok, and Moojong Park. "A Study on the Development of Reduction Facilities’ Management Standards for Agricultural Drainage for Disaster Reduction." Sustainability 13, no. 17 (August 26, 2021): 9595. http://dx.doi.org/10.3390/su13179595.
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The agricultural drainage in rural area plays important roles in water supply and drainage for crop cultivation. Various kinds of debris near agricultural drainage, however, causes sedimentation in the drainage during rainfall. The debris introduced into the agricultural drainage moves out of the drainage under a high flow rate. This causes a reduction in the flow rate, which may affect the discharge capacity, resulting in crop damage. This study developed a reduction facility to reduce debris entering agricultural drainage and analyzed the performance by measuring the capture efficacy in the hydraulic experiment. A total of 648 runs were performed for 216 experiment conditions where three replications and error ranges were calculated depending on the inflow characteristics of debris. This study also evaluated the performance of the reduction facility and established the design criteria by developing a capture efficacy equation by flow rate and type of reduction facility.
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Nasyirah, Nibras, Dedi Kalsim, and Satyanto Saptomo. "Analysis of The Rate of Saline Soil Leaching by Using Subsurface Drainage." Jurnal Keteknikan Pertanian 03, no. 2 (October 1, 2015): 1–8. http://dx.doi.org/10.19028/jtep.03.2.89-96.
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Starkov, Yu G., R. D. Zamolodchikov, S. V. Dzhantukhanova, M. I. Vyborniy, K. V. Lukich, A. S. Ibragimov, I. M. Goncharov, and V. Yu Lavrentyeva. "The results of endosonography-assisted internal drainage of pancreatic pseudocyst." Annaly khirurgicheskoy gepatologii = Annals of HPB surgery 24, no. 1 (April 2, 2019): 43–52. http://dx.doi.org/10.16931/1995-5464.2019143-52.
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Aim.To compare immediate and long-term results of internal drainage of pancreatic pseudocyst by using of endosonography-assisted and open surgical approaches.Material and methods.EUS-assisted internal drainage of pancreatic pseudocyst was performed in 32 patients in 2011–2016. Open drainage procedures were carried out on the other 32 patients.Results.In the group of endoscopic drainage, technical success rate, clinical success rate and complication rate were 97%, 85% and 26%, respectively. There were no recurrent pseudocysts in long-term period. Comparison with open surgery confirmed advantages of endoscopic technique regarding time of operation (p< 0.01), intraoperative blood loss (p< 0.01) and length of hospital-stay (p< 0.01).Conclusion.EUS-assisted internal drainage of pancreatic pseudocysts in the treatment of chronic pancreatitis is characterized by high rate of technical and clinical success, small postoperative morbidity and low incidence of longterm recurrences.
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Rungsakulkij, Narongsak, Varinthip Thongchai, Wikran Suragul, Watoo Vassanasiri, Pongsatorn Tangtawee, Paramin Muangkaew, Somkit Mingphruedhi, and Suraida Aeesoa. "Association of the rate of bilirubin decrease with major morbidity in patients undergoing preoperative biliary drainage before pancreaticoduodenectomy." SAGE Open Medicine 9 (January 2021): 205031212110396. http://dx.doi.org/10.1177/20503121211039667.
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Objective: The objective of this study was to examine the relationship between the rate of bilirubin decrease following preoperative biliary drainage before pancreaticoduodenectomy and postoperative morbidity. Methods: Records of patients who underwent pancreaticoduodenectomy at the Department of Surgery in Ramathibodi Hospital between January 2008 and December 2019 were retrospectively reviewed. The patients were classified into either an adequate or inadequate drainage rate groups according to the bilirubin decrease rate. Major morbidity was defined as higher than grade II in the Clavien-Dindo classification. Risk factors for major morbidity were analyzed by logistic regression analysis. Results: In total, 166 patients were included in the study. Major morbidity was observed in 36 patients (21.6%). Adequate biliary drainage rate was observed in 39 patients (23.4%). Patients who had major morbidity were less likely to have come from the adequate biliary drainage rate group than the inadequate group (38.9% vs. 61.1%). However, through multivariate logistic analysis, only body mass index, operative time, and pancreatic duct diameter were independent factors associated with major morbidity, whereas the bilirubin decrease rate was not. Conclusions: Bilirubin decrease rate following preoperative biliary drainage has no significant association with major postoperative morbidity after pancreaticoduodenectomy.
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Tsutsumi, Kazuo, Keiichirou Maeda, Akira Iijima, Masaaki Usui, Yoshihumi Okada, and Takaaki Kirino. "The relationship of preoperative magnetic resonance imaging findings and closed system drainage in the recurrence of chronic subdural hematoma." Journal of Neurosurgery 87, no. 6 (December 1997): 870–75. http://dx.doi.org/10.3171/jns.1997.87.6.0870.
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✓ Although chronic subdural hematoma (CSDH) is a well-known entity, its recurrence rate has remained uncertain. There is little knowledge concerning whether the results of radiological imaging can be used to predict CSDH recurrence or whether surgical methods can influence this rate. The first aim of this study is to evaluate the relationship between the recurrence rate of CSDHs and their appearance on preoperative magnetic resonance (MR) or computerized tomography images. The second aim is to evaluate by means of a prospective randomized method the usefulness of closed-system drainage. From January 1988 through June 1996, the authors surgically treated 257 consecutive adult patients with CSDHs. Data obtained in 199 patients who were evaluated preoperatively by MR imaging were analyzed. Thirty-one of these patients underwent bilateral operations and thus 230 operative sites of CSDH were included in the analyses. The cases of CSDH were separated into high- and nonhigh-intensity groups on the basis of the appearance on T1-weighted MR images. From July 1992 to June 1996, the authors conducted a prospective randomized study on the recurrence rate of CSDH in patients undergoing burr-hole irrigation with or without closed system drainage. The recurrence rate of 3.4% in the high-intensity group was significantly lower than the 11.6% rate found in the nonhigh-intensity group (p < 0.05). The recurrence rates following irrigation with and without closed system drainage were significantly different (p < 0.025): 3.1% with closed system drainage and 17% following burr-hole irrigation alone. The surgical procedures were correlated with the MR findings. In the high-intensity group, 1.1% of CSDHs recurred in patients in whom closed system drainage was used and 11.1% in patients without closed system drainage. In the nonhigh-intensity group, 8.1% of CSDHs recurred in patients in whom drainage was used and 23.1% in patients without closed system drainage. Magnetic resonance T1-weighted imaging was useful in predicting the propensity of CSDHs to recur. Closed system drainage significantly reduced the recurrence rate of CSDHs regardless of MR findings.
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Bishawi, Muath, Bradley Feiger, Neel Kurupassery, Konstantinos Economopoulos, Paul Suhocki, Theodore Pappas, George Truskey, and Amanda Randles. "Drainage Performance of a Novel Catheter Designed to Reduce Drainage Catheter Failure." Journal of Clinical Interventional Radiology ISVIR 4, no. 01 (April 2020): 09–15. http://dx.doi.org/10.1055/s-0040-1708570.
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Abstract Objective Efficient flow of fluids through drainage/infusion catheters is affected by surrounding tissue, organ compression, and scar tissue development, limiting or completely obstructing flow through drainage holes. In this work, we introduce a novel three-dimensional (3D) drainage catheter with protected side holes to reduce flow blockages. We then compare its drainage performance to standard straight and pigtail catheters using computer-generated catheter designs and flow analysis software. Methods Drainage performance was computed as flow rate through the catheter for a given pressure differential. Each catheter contained drainage holes on the distal (insertion) end and a single outlet (hub) hole open to atmosphere. Computational fluid dynamics using ANSYS AIM 18.2 was used to simulate flow through the catheter and examine drainage performance based on variations to the following parameters: (1) side hole shape, (2) cross-sectional area of the catheters, (3) number of side holes, and (4) cross-sectional area of the side holes. Results Drainage through the newly introduced catheter in all simulations was nearly identical to standard pigtail and straight catheters. While working to optimize the 3D catheter design, we found that the changes in side hole shape and side hole cross-sectional area had little effect on the total flow rate through the catheters but had a large impact on flow rate through the side hole nearest to the hub (proximal hole). Additionally, the majority of flow in all catheters occurred at the most proximal 1 to 3 side holes closest to hub, with relatively little flow occurring at side holes more distally located (closest to insertion end). The 3D catheter demonstrated no changes in flow characteristics when the coiled segment was occluded, giving it an advantage over other catheter types when the catheter is compressed by surrounding tissue or other external obstruction. Conclusions The majority of fluid flow in catheters with a diameter of 4.67 mm (14 Fr) or smaller occurred at the most proximal 1 to 3 side holes. A novel 3D coiled catheter design can protect these proximal holes from external blockage while maintaining drainage performance compared with standard straight and pigtail catheters.
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Dickson, K. A., and R. Harding. "Decline in lung liquid volume and secretion rate during oligohydramnios in fetal sheep." Journal of Applied Physiology 67, no. 6 (December 1, 1989): 2401–7. http://dx.doi.org/10.1152/jappl.1989.67.6.2401.
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Reduced amniotic fluid volume often results in fetal lung hypoplasia. Our aim was to examine the effects of prolonged drainage of amniotic and allantoic fluids on lung liquid volume (Vl), secretion rate (Vs), and tracheal flow rate (Vtr) in fetal sheep. In five experimental animals, amniotic and allantoic fluids were drained from 107 to 135 days of gestation. The volume of fluid drained from the experimental animals was 411.8 +/- 24.4 ml/day (n = 140). In six control animals, amniotic fluid volume was 747.7 +/- 89.7 ml (n = 15). Wet and dry lung weights were 20-25% lower in experimental fetuses than in control fetuses. Fetal hemoglobin, O2 saturation, arterial PO2, pH, and hematocrit were unchanged by drainage. During the drainage period, Vl was up to 65% lower, Vs was up to 35% lower, and Vtr was up to 40% lower in experimental fetuses than in control fetuses. We conclude that prolonged drainage of amniotic and allantoic fluids decreases Vl, Vs, and Vtr in fetal sheep. These findings indicate that fetal lung hypoplasia associated with oligohydramnios may be the result of a prolonged reduction in Vl.
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Xu, Ming, and You-Liang Tao. "Drainage versus No Drainage after Laparoscopic Cholecystectomy for Acute Cholecystitis: A Meta-Analysis." American Surgeon 85, no. 1 (January 2019): 86–91. http://dx.doi.org/10.1177/000313481908500138.
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To conduct a randomized controlled trial (RCT), meta-analysis to assess the effectiveness of drains in reducing complications after laparoscopic cholecystectomy (LC) for acute cholecystitis needs to be carried out. An electronic search of PubMed, Embase, Science Citation Index, and the Cochrane Library from January 1990 to January 2018 was performed to identify randomized clinical trials that compare prophylactic drainage with no drainage in LC for acute cholecystitis. The outcomes were calculated as odds ratios (ORs) with 95 per cent confidence intervals (CIs) using RevMan 5.2. Four RCTs, which included 796 patients, were identified for analysis in our study. There was no statistically significant difference in the rate of morbidities (OR = 1.23, 95% CI 0.55–2.76, P = 0.61). Abdominal pain was more severe in the drain group 24 hours after surgery (mean difference = 0.80, 95% CI 0.47–1.14; P < 0.00001). No significant difference was present with respect to wound infection rate and hospital stay. The use of abdominal drainage does not appear to be of any benefit in patients having undergone early LC for acute cholecystitis.
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LUO, Jianhong, Jun LI, Ping HUANG, and Meiying HUANG. "Kinetic Rate Constant of Liquid Drainage from Colloidal Gas Aphrons." Chinese Journal of Chemical Engineering 17, no. 6 (December 2009): 955–59. http://dx.doi.org/10.1016/s1004-9541(08)60302-x.
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Si, Bing C., and Eeltje de Jong. "Determining Long-Term (Decadal) Deep Drainage Rate Using Multiple Tracers." Journal of Environmental Quality 36, no. 6 (November 2007): 1686–94. http://dx.doi.org/10.2134/jeq2007.0029.
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David Suits, L., TC Sheahan, C.-Y. Yune, and C.-K. Chung. "Consolidation Test at Constant Rate of Strain for Radial Drainage." Geotechnical Testing Journal 28, no. 1 (2005): 11922. http://dx.doi.org/10.1520/gtj11922.
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Vranešević, Milica, Andrea Salvai, Atila Bezdan, and Radoš Zemunac. "Assessment of Runoff and Drainage Conditions in a North Banat Sub-Catchment, North-Eastern Serbia." Journal of Environmental Geography 12, no. 3-4 (November 1, 2019): 13–19. http://dx.doi.org/10.2478/jengeo-2019-0008.
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Abstract The lowland area of the southeastern part of the Carpathian Basin is exposed to extreme hydrological conditions. The monitoring and analysis of the excess inland water are necessary in order to understand the scope and direction of the development of this type of flooding. When solving the problem of the drainage of an area and dimensioning drainage systems, one of the most important steps is to calculate the rate of runoff. Before calculating the rate of runoff, it is necessary to perform various analysis such as: hydrological, hydrogeological, pedological and land use analysis. The use of empirical formulas by different authors is one of the methods for determining the rate of runoff. These formulas can be of regional character, while some are applicable in different parts of the world. In this paper, the runoff coefficient and rate of runoff were calculated as indicators of the efficiency of the area drainage, employing the formulas by Nemet and Turazzo. The emphasis was put on the usage of modern tools and databases of soil characteristics while using a “traditional” method to determine rate of runoff. The obtained results demonstrate that the rate of runoff which reflects the current state of the drainage basin is very similar to the rate of runoff used for dimensioning of drainage system. The problem of retaining smaller amounts of water that remains even after the anticipated drainage deadlines can be solved with the regular maintenance of amelioration canals and additional ameliorative measures.
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Feng, Jian Gang, Li Feng Bu, You Wei Xu, and Bin Mao. "Research on the Field Test Methods of Flow Rate and Water Level of Urban Drainage Pumping Stations." Advanced Materials Research 718-720 (July 2013): 903–7. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.903.
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The flow rate and water level measure is one key work of the pumping station field test. And the reliable, applicable, economic and effective measurement method and instruments are the key decisive factors of the field test. The urban drainage pumping stations usually pump sewage, and its inlet structure and outlet structure generally use closed arrangement. These make the flow rate and water level measurement of the field test become complicated. Based on the characteristics of urban drainage pumping station, this paper analyzed the measurement methods of flow rate and water level parameters of the field test for urban drainage pumping station. In combination with a field test case for an urban drainage pumping station, this paper demonstrated how to choose the reliable, applicable, economic and effective measurement method to measure flow rate and water level parameters.
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Silins, U., and R. L. Rothwell. "Spatial patterns of aerobic limit depth and oxygen diffusion rate at two peatlands drained for forestry in Alberta." Canadian Journal of Forest Research 29, no. 1 (January 1, 1999): 53–61. http://dx.doi.org/10.1139/x98-179.
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The spatial variability of soil aeration (aerobic limit depth and oxygen diffusion rate (ODR)) among different drainage ditch spacings and at various distances from drainage ditches was examined at two peatlands drained for forestry in north-central Alberta. Drainage lowered mean water table levels (p < 0.001) at both peatlands. Lower water table levels within drained areas were associated with greater aerobic limit depths (p < 0.001) and greater ODR (p < 0.001 at Saulteaux River; p < 0.027 at Wolf Creek) compared with undrained areas of both peatlands. Spatial patterns of aerobic limit depth and ODR indicated strong spatial variability of soil aeration in the immediate vicinity of drainage ditches. However, little sensitivity of soil aeration to different ditch spacings was evident. Potential effects of post-drainage subsidence on soil aeration was evident as increased distance of both the aerobic limit, and near-zero oxygen diffusion rates above the water table surface at both peatlands. One effect of post-drainage peatland subsidence may be to increase the thickness of the capillary zone above the water table. However, reduction of aeration within the rooting zone of peatland trees due to subsidence was not observed because of low water tables within the drained areas of both peatlands.
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Smith, Benjamin E., Noel Gourmelen, Alexander Huth, and Ian Joughin. "Connected subglacial lake drainage beneath Thwaites Glacier, West Antarctica." Cryosphere 11, no. 1 (February 8, 2017): 451–67. http://dx.doi.org/10.5194/tc-11-451-2017.
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Abstract. We present conventional and swath altimetry data from CryoSat-2, revealing a system of subglacial lakes that drained between June 2013 and January 2014 under the central part of Thwaites Glacier, West Antarctica (TWG). Much of the drainage happened in less than 6 months, with an apparent connection between three lakes spanning more than 130 km. Hydro-potential analysis of the glacier bed shows a large number of small closed basins that should trap water produced by subglacial melt, although the observed large-scale motion of water suggests that water can sometimes locally move against the apparent potential gradient, at least during lake-drainage events. This shows that there are important limitations in the ability of hydro-potential maps to predict subglacial water flow. An interpretation based on a map of the melt rate suggests that lake drainages of this type should take place every 20–80 years, depending on the connectivity of the water flow at the bed. Although we observed an acceleration in the downstream part of TWG immediately before the start of the lake drainage, there is no clear connection between the drainage and any speed change of the glacier.
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Nakaguchi, Hiroshi, Takeo Tanishima, and Norio Yoshimasu. "Relationship between drainage catheter location and postoperative recurrence of chronic subdural hematoma after burr-hole irrigation and closed-system drainage." Journal of Neurosurgery 93, no. 5 (November 2000): 791–95. http://dx.doi.org/10.3171/jns.2000.93.5.0791.
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Object. This study was conducted to determine the best position for the subdural drainage catheter to achieve a low recurrence rate after burr-hole irrigation and closed-system drainage of chronic subdural hematoma (CSDH).Methods. The authors studied 63 patients with CSDH in whom the drainage catheter tip was randomly placed and precisely determined on postoperative computerized tomography (CT) scans and 104 patients with CSDH in whom CT scans were obtained 7 days postsurgery. The location of the subdural drainage catheter, the maximum postoperative width of the subdural space, and the percentage of the ipsilateral subdural space occupied by air postoperatively were determined and compared with the postoperative recurrence and reoperation rates.Patients with parietal or occipital drainage had a higher rate of CSDH recurrence and much more subdural air than those with frontal drainage. In addition, patients with residual subdural air demonstrated on CT scans obtained 7 days postsurgery also had a higher recurrence rate than those without subdural air collections. Furthermore, patients with a subdural space wider than 10 mm on CT scans obtained 7 days postsurgery had a higher recurrence rate than those with a space measuring 10 mm or less.Conclusions. The incidence of postoperative fluid reaccumulation seems to be reduced by placing the tip of the drainage catheter in the frontal convexity and by removing subdural air during or after surgery.
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Upadhyay, Hemant, and T. K. Kundu. "Drain Rate and Liquid Level Simulation in Blast Furnace Hearth Using Plant Data." ISRN Metallurgy 2013 (July 30, 2013): 1–7. http://dx.doi.org/10.1155/2013/960210.
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Proper understanding and control of drainage of hot metal and slag from hearth are essential for a stable and efficient blast furnace operation. Various operational problems like irregular casting intervals, damage to lining, low blast intake, furnace pressurization, and so forth are normally encountered when liquid levels in the hearth exceed a critical limit where hearth coke and deadman start to float. Estimation of drain rate and liquid level in hearth needs to be simulated based on the operating parameters available as carrying out any direct measurement is extremely difficult due to the hostile conditions. Here, a mathematical model has been developed to simulate real-time liquid level and drainage behavior of the furnace hearth. Based on the computed drainage rate, production rate, and mass balance, the model is able to predict occurrence of slag-out time and cast close time which are in good agreement with the plant data.
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Hakuta, Ryunosuke, Hirofumi Kogure, Yousuke Nakai, Hiroshi Kawakami, Hiroyuki Maguchi, Tsuyoshi Mukai, Takuji Iwashita, et al. "Unilateral versus Bilateral Endoscopic Nasobiliary Drainage and Subsequent Metal Stent Placement for Unresectable Malignant Hilar Obstruction: A Multicenter Randomized Controlled Trial." Journal of Clinical Medicine 10, no. 2 (January 8, 2021): 206. http://dx.doi.org/10.3390/jcm10020206.
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(1) Background: Endoscopic management of hilar biliary obstruction is still challenging. Compared with unilateral drainage, bilateral drainage could preserve larger functional liver volume and potentially improve clinical outcomes. To evaluate the effectiveness of bilateral drainage, we conducted this multicenter randomized controlled study. (2) Methods: Patients with unresectable malignant hilar biliary obstruction were assigned to unilateral or bilateral group. At first, patients underwent endoscopic nasobiliary drainage (ENBD), and subsequently underwent self-expandable metallic stent (SEMS) deployment. Primary outcomes were the functional success rate of ENBD and time to recurrent biliary obstruction (TRBO) after SEMS deployment. (3) Results: During the study period, 38 and 39 patients were enrolled in the unilateral and bilateral groups. The functional success rate was similar in the uni- and bi-ENBD group (57% vs. 56%; p = 0.99), but the rate of additional drainage was higher in uni-ENBD group. Although TRBO and overall survival time after SEMS deployment were not different between the groups (p = 0.11 and 0.78, respectively), the incidence of early adverse events tended to be higher in the bi-SEMS group (5.3% vs. 28%; p = 0.11). (4) Conclusions: Our study failed to demonstrate the superiority of bilateral over unilateral biliary drainage in terms of functional success rate and TRBO.
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Hakuta, Ryunosuke, Hirofumi Kogure, Yousuke Nakai, Hiroshi Kawakami, Hiroyuki Maguchi, Tsuyoshi Mukai, Takuji Iwashita, et al. "Unilateral versus Bilateral Endoscopic Nasobiliary Drainage and Subsequent Metal Stent Placement for Unresectable Malignant Hilar Obstruction: A Multicenter Randomized Controlled Trial." Journal of Clinical Medicine 10, no. 2 (January 8, 2021): 206. http://dx.doi.org/10.3390/jcm10020206.
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(1) Background: Endoscopic management of hilar biliary obstruction is still challenging. Compared with unilateral drainage, bilateral drainage could preserve larger functional liver volume and potentially improve clinical outcomes. To evaluate the effectiveness of bilateral drainage, we conducted this multicenter randomized controlled study. (2) Methods: Patients with unresectable malignant hilar biliary obstruction were assigned to unilateral or bilateral group. At first, patients underwent endoscopic nasobiliary drainage (ENBD), and subsequently underwent self-expandable metallic stent (SEMS) deployment. Primary outcomes were the functional success rate of ENBD and time to recurrent biliary obstruction (TRBO) after SEMS deployment. (3) Results: During the study period, 38 and 39 patients were enrolled in the unilateral and bilateral groups. The functional success rate was similar in the uni- and bi-ENBD group (57% vs. 56%; p = 0.99), but the rate of additional drainage was higher in uni-ENBD group. Although TRBO and overall survival time after SEMS deployment were not different between the groups (p = 0.11 and 0.78, respectively), the incidence of early adverse events tended to be higher in the bi-SEMS group (5.3% vs. 28%; p = 0.11). (4) Conclusions: Our study failed to demonstrate the superiority of bilateral over unilateral biliary drainage in terms of functional success rate and TRBO.
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Chávez-Gómez, Viridiana, José Chávez-Monter, Jaime Ordoñez-Granja, Yarel Barba-Ruiz, Rafael Avendaño-Pradel, Edgardo Ruiz-García, and Carlos Castillo-Rangel. "Treatment of Subdural Hematoma: Comparative Analysis between Subdural Drainage with Negative Pressure versus other Drainages." International Journal of Medical and Surgical Sciences 4, no. 1 (October 27, 2018): 1089–99. http://dx.doi.org/10.32457/ijmss.2017.001.
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Report the recurrence rate of negative pressure subdural drainage (NPSD) versus to other kind of drains (OD). Design and Methods: A study was conducted cross-sectional and we retrospectively analyzed on the database of the neurosurgical service and we looked for all surgical procedures recorded from January 2006 to December 2015. Procedures with preoperative diagnosis of subdural hematoma (SDH) were selected, with a to- tal of 364 interventions, were excluded patients with postoperative diagnosis different from SDH and eliminated those who did not have complete data, recurrence was identified, a statistical analysis was performed describing frequency measurements percentage and standard deviation, RM and chi- square was obtained by software EPIDAT 3.1. 277 surgeries were performed in 230 patients, The population was divided into two groups: the first those interventions with negative pressure subdural drainage versus a second group with other different drains, and finally we compared the recurrence rate in each group, 44 surgeries had recurrence of SDH. The proportion of recurrence was found 16 % of the surgeries, 16 % (n=7) of these were performed with negative pressure subdural drainage and the remaining 84 % (n=37) by other drainage. The reason for prevalence found was 0.36 (95 % CI , 0.15 to 0.85), with statistically significant differences (p = 0.0165). The chi-square was 5.75 for the SDH with NPSD. It was found that patients treated with NPSD have a lower risk of recurrence compared with OD, which acts as a protective factor for patients treated with this type of drain, this is statistically significant.
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Ba, Yongjiang, Ping Yue, Joseph W. Leung, Haiping Wang, Yanyan Lin, Bing Bai, Xiaoliang Zhu, et al. "Percutaneous transhepatic biliary drainage may be the preferred preoperative drainage method in hilar cholangiocarcinoma." Endoscopy International Open 08, no. 02 (January 22, 2020): E203—E210. http://dx.doi.org/10.1055/a-0990-9114.
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Abstract Background and study aims Preoperative biliary drainage of hilar cholangiocarcinoma (HC) is controversial. The goal of this study was to compare the clinical outcome and associated complications for types II, III, and IV HC managed by percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP). Patients and methods Between January 2011 and June 2017, a total of 180 patients with II, III, and IV HC were enrolled in this retrospective cohort study. According to the drainage method, patients were divided into two groups: PTBD (n = 81) and ERCP (n = 99). This study was registered with ClinicalTrials.gov, NCT03104582, and was completed. Results Compared with the PTBD group, the ERCP group had a higher incidence of post-procedural cholangitis (37 [37.37 %] vs. 18 [22.22 %], P = 0.028) and pancreatitis (17 [17.17 %] vs. 2 [2.47 %], P = 0.001); required more salvaged biliary drainage (18 [18.18 %] vs. 5 [6.17 %], P = 0.029), and incurred a higher cost (P < 0.05). Patients with type III and IV HC in the ERCP group had more cholangitis than those in the PTBD group (26 [36.62 %] vs. 11 [18.03 %], P = 0.018). The rate of cholangitis in patients who received endoscopic bilateral biliary stents insertion was higher than patients with unilateral stenting (23 [50.00 %] vs. 9 [26.47 %], P = 0.034), and underwent PTBD internal-external drainage had a higher incidence of cholangitis than those with only external drainage (11 [34.36 %] vs. 7 [14.29 %], P = 0.034). No significant difference in the rate of cholangitis was observed between the endoscopic unilateral stenting group and the endoscopic nasobiliary drainage group (9 [26.47 %] vs. 5 [26.32 %], P = 0.990). Conclusion Compared to ERCP, PTBD reduced the rate of cholangitis, pancreatitis, salvage biliary drainage, and decreased hospitalization costs in patients with types II, III, and IV HC. Risk of cholangitis for patients with types III and IV was significantly lower in the PTBD group.
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Giovannini, Marc, and Erwan Bories. "EUS-Guided Biliary Drainage." Gastroenterology Research and Practice 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/348719.
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The echoendoscopic biliary drainage is an option to treat obstructive jaundices when ERCP drainage fails. These procedures compose alternative methods to the side of surgery and percutaneous transhepatic biliary drainage, and it was only possible by the continuous development and improvement of echoendoscopes and accessories. The development of linear setorial array echoendoscopes in early 1990 brought a new approach to diagnostic and therapeutic dimenion on echoendoscopy capabilities, opening the possibility to perform punction over direct ultrasonographic view. Despite of the high success rate and low morbidity of biliary drainage obtained by ERCP, difficulty could be found at the presence of stent tumor ingrown, tumor gut compression, periampulary diverticula, and anatomic variation. The echoendoscopic technique starts performing punction and contrast of the left biliary tree. When performed from gastric wall, the access is made through hepatic segment III. From duodenum, direct common bile duct punction. Dilatation is required before stent introduction, and a plastic or metallic stent is introduced. This phrase should be replaced by: diathermic dilatation of the puncturing tract is required using a 6F cystostome. The technical success of hepaticogastrostomy is near 98%, and complications are present in 36%: pneumoperitoneum, choleperitoneum, infection, and stent disfunction. To prevent bile leakage, we have used the 2 stent techniques, the first stent introduced was a long uncovered metallic stent (8 or 10 cm), and inside this first stent a second fully covered stent of 6 cm was delivered to bridge the bile duct and the stomach. Choledochoduodenostomy overall success rate is 92% and described complications include, in frequency order, pneumoperitoneum and focal bile peritonitis, present in 19%. By the last 10 years, the technique was especially performed in reference centers, by ERCP experienced groups, and this seems to be a general guideline to safer procedure execution.
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Poinar, Kristin, and Lauren C. Andrews. "Challenges in predicting Greenland supraglacial lake drainages at the regional scale." Cryosphere 15, no. 3 (March 24, 2021): 1455–83. http://dx.doi.org/10.5194/tc-15-1455-2021.
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Abstract. A leading hypothesis for the mechanism of fast supraglacial lake drainages is that transient extensional stresses briefly allow crevassing in otherwise compressional ice flow regimes. Lake water can then hydrofracture a crevasse to the base of the ice sheet, and river inputs can maintain this connection as a moulin. If future ice sheet models are to accurately represent moulins, we must understand their formation processes, timescales, and locations. Here, we use remote-sensing velocity products to constrain the relationship between strain rates and lake drainages across ∼ 1600 km2 in Pâkitsoq, western Greenland, between 2002–2019. We find significantly more extensional background strain rates at moulins associated with fast-draining lakes than at slow-draining or non-draining lake moulins. We test whether moulins in more extensional background settings drain their lakes earlier, but we find insignificant correlation. To investigate the frequency at which strain-rate transients are associated with fast lake drainage, we examined Landsat-derived strain rates over 16 and 32 d periods at moulins associated with 240 fast-lake-drainage events over 18 years. A low signal-to-noise ratio, the presence of water, and the multi-week repeat cycle obscured any resolution of the hypothesized transient strain rates. Our results support the hypothesis that transient strain rates drive fast lake drainages. However, the current generation of ice sheet velocity products, even when stacked across hundreds of fast lake drainages, cannot resolve these transients. Thus, observational progress in understanding lake drainage initiation will rely on field-based tools such as GPS networks and photogrammetry.
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Li, Siqian. "Engineering Practice of Ultra-high Pressure Hydraulic Slotting and Pressure Relief Pumping in Through Layer Hole." E3S Web of Conferences 236 (2021): 01029. http://dx.doi.org/10.1051/e3sconf/202123601029.
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In order to solve the problems of low gas drainage rate and long drainage time in thick coal seam with low permeability, ultra-high pressure hydraulic slotting pressure relief and permeability enhancement technology was applied in the test. The practice shows that after adopting the ultra-high pressure hydraulic slotting, the gas drainage rate is greatly improved, the time for reaching the standard of drainage is shortened, and the difficult problem of gas control in the mining face of thick coal seam is solved, which provides technical guidance for high-efficiency gas control in thick coal seam with similar conditions in mining area.
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Dufková, R., T. Kvítek, and J. Voldřichová. "Soil organic carbon and nitrogen characteristics in differently used grasslands at sites with drainage and without drainage." Plant, Soil and Environment 51, No. 4 (November 19, 2011): 165–72. http://dx.doi.org/10.17221/3570-pse.
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Extensive management (absence of management) of unfertilized permanent grasslands was examined for five years from the aspect of its influence on soil chemical properties of horizon A in a floodplain locality of the Crystalline Complex, in relation to water regime regulation, reclamations and liming. These treatments: without mowing (0), one cut (1) and two cuts (2) per year were used at sites without drainage (WD), with drainage (D) and with drainage water retardation (R). These average values were measured at all sites and for all treatments: content of soil organic carbon C<sub>org</sub> 2.3–3.4%, combustible substances CS 12–15%, humic to fulvic acids ratio C<sub>HA</sub>/C<sub>FA</sub> 0.81–0.94, C/N 8–9, humification rate 0.6–0.7, exchange pH 3.9–5.1. All sites have deteriorated conditions for the activity of soil microorganisms (low pH). Determinations of the contents of organic carbon (C<sub>org</sub> by thermal combustion, water soluble and hot water soluble carbon, C<sub>HA</sub> and C<sub>FA</sub>), CS and total nitrogen indicated decreases as a result of the influence of factors (drainage, liming, mowing) supporting mineralization and the cycle of soil organic matter. Mowing improved humus quality
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Amir, Ida, Pradeep Morar, and Antonio Belloso. "Postoperative drainage in head and neck surgery." Annals of The Royal College of Surgeons of England 92, no. 8 (November 2010): 651–54. http://dx.doi.org/10.1308/003588410x12699663904754.
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INTRODUCTION A major factor affecting patients’ length of hospitalisation following head and neck surgery remains the use of surgical drains. The optimal time to remove these drains has not been well defined. A routine practice is to measure the drainage every 24 h and remove the drain when daily drainage falls below 25 ml. This study aims to determine whether drainage measurement at shorter intervals decreases the time to drain removal and hence the length of in-patient stays. PATIENTS AND METHODS A 6-month prospective observational study was performed. The inclusion criteria were patients who underwent head and neck surgery without neck dissection and had a closed suction drain inserted. Drainage rates were measured at 8-hourly intervals. Drains were removed when drainage-rate was ≤ 1 ml/h over an 8-h period. RESULTS A total of 43 patients were evaluated. The highest drainage rate occurred in the first 8 postoperative hours and decreased significantly in the subsequent hours. The median drainage rates at 8, 16, 24, 32 and 40 postoperative hours were 3.375, 1, 0, 0 and 0 ml/h, respectively. Applying our new removal criteria of ≤ 1 ml/h drainage rate, the drains were removed in 22 (51%) patients at the 16th postoperative hour; 37 (86%) were removed by 24 h after operation. In comparison, only nine (20.9%) patients could potentially be discharged the day after surgery if previous criteria of ≤ 25 ml/24-h were used to decide on drain removal. CONCLUSIONS Our 8-hourly drainage-rate monitoring has facilitated safe earlier discharge of an additional 28 (65%) patients on the day after surgery. This has led to improvement in patient care, better optimisation of hospital resources and resulted in positive economic implications to the department.
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Tortajada, Pauline, Alain Sauvanet, Stephanie Truant, Nicolas Regenet, Régis Souche, Stéphane Benoist, Fabrice Muscari, et al. "Does Fungal Biliary Contamination after Preoperative Biliary Drainage Increase Postoperative Complications after Pancreaticoduodenectomy?" Cancers 12, no. 10 (September 30, 2020): 2814. http://dx.doi.org/10.3390/cancers12102814.
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(1) Background: preoperative biliary drainage before pancreaticoduodenectomy (PD) is associated with bacterial biliary contamination (>85%) and a significant increase in global and infectious complications. In view of the lack of published data, the aim of our study was to investigate the impact of fungal biliary contamination after biliary drainage on the complication rate after PD. (2) Methods: a multicentric retrospective study that included 224 patients who underwent PD after biliary drainage with intraoperative biliary culture. (3) Results: the global rate of positive intraoperative biliary sample was 92%. Respectively, the global rate of biliary bacterial contamination and the rate of fungal contamination were 75% and 25%, making it possible to identify two subgroups: bacterial contamination only (B+, n = 154), and bacterial and fungal contamination (BF+, n = 52). An extended duration of preoperative drainage (62 vs. 49 days; p = 0.08) increased the risk of fungal contamination. The overall and infectious complication rates were not different between the two groups. In the event of postoperative infectious or surgical complications, the infectious samples taken did not reveal more fungal infections in the BF+ group. (4) Conclusions: fungal biliary contamination, although frequent, does not seem to increase the rate of global and infectious complications after PD, preceded by preoperative biliary drainage.
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Zhou, Qiao-Nian, and W. P. Graebel. "Free-Surface Oscillations in a Slowly Draining Tank." Journal of Applied Mechanics 59, no. 2 (June 1, 1992): 438–44. http://dx.doi.org/10.1115/1.2899539.
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The initial behavior of a free surface in a draining (filling) circular tank is analyzed using a linearized model. The withdrawal (injection) of fluid damps (enhances) oscillations which either exist before the withdrawal (filling) or are induced by the withdrawal (injection). The initial growth rate of the drainage-initiated free-surface oscillations strongly depends on the initial behavior of the drain rate function. If the drain is turned on gradually, the drainage-initiated free-surface oscillation is weaker compared to the forced one, so there are no drainage-initiated oscillations. However, if the drain is turned on suddenly, the induced oscillatory motion dominates the forced motion. For periodic drainage, the results show that the strongest resonant oscillation occurs when the drainage frequency w coincides with the first natural frequency of the flow system. All of the nonresonant modes of the oscillations are stable regardless of the initial behavior of the drain rate. If q(t) = sinωt, all of the resonant oscillations are stable. In the case when q(t) = cosωt, the initial jump in the drainage means that the resonance modes can be either unconditionally unstable, unconditionally stable, or conditionally unstable, depending on the various parameters.
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Uda, Hiroshi, Alhusain Nagm, Tsutomu Ichinose, Yohei Onishi, Masaki Yoshimura, Takashi Tsuruno, and Kenji Ohata. "Burr hole drainage without irrigation for chronic subdural hematoma." Surgical Neurology International 11 (May 2, 2020): 89. http://dx.doi.org/10.25259/sni_550_2019.
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Background: Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions, with different strategies for treatment. Most recent trials favor the use of drainage to reduce the recurrence rate. However, few reports have discussed the efficacy of burr hole drainage without irrigation for treating CSDH. This study aimed to examine the efficacy of burr hole drainage without irrigation in a series of 385 symptomatic CSDH lesions. Methods: This retrospective study included a series of 385 symptomatic CSDH lesions in 309 patients, who underwent burr hole drainage without irrigation, between September 2009 and August 2017 at the Department of Neurosurgery, Yao Tokushukai General Hospital, Japan. The risk of recurrence was evaluated based on the patients’ age, sex, preoperative magnetic resonance imaging (MRI) findings, preoperative anticoagulants, hematoma drainage rate, and bilaterality. Results: Of the 385 lesions, 41 cases (16 with inadequate follow-up periods and 25 with contraindications for MRI) were excluded from the analysis. The overall recurrence rate in the index study was 4.9% (17/344 lesions). The effects of the preoperative hematoma volume and nonhyperintensity on T1-weighted imaging on the recurrence rate were significant. Conclusion: Our findings indicated that burr hole drainage without irrigation is a good surgical modality in patients with CSDH, and preoperative MRI findings can evaluate the risk of recurrence.
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Wushouer, Abuduwaili, Ma Mu Ti Jiang A Ba Bai Ke Re, and Irshat Ibrahim. "Outcome of hybrid seton placement for the treatment of high complex anal fistulas with and without tube drainage: A prospective comparative study." European Journal of Inflammation 15, no. 2 (June 19, 2017): 124–30. http://dx.doi.org/10.1177/1721727x17715581.
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The aim of this study was to investigate the efficacy of treatment for complex anal fistula with cutting hybrid seton combined with tube drainage. A total of 66 consecutive patients with complex anorectal fistulae were divided into two groups: experimental group (group A with 36 patients) underwent cutting hybrid seton placement plus tube drainage and control group (group B with 30 patients) underwent same procedure without tube drainage. Comparison of clinical outcomes between two groups was conducted. The success rate, time for healing of the wound, postoperative pain, and recurrence rate were analyzed. No patient was lost to follow-up. Some major clinical outcomes presented significant differences. Experimental group was superior than the control group in the aspects of success rate, time for healing of the wound, postoperative pain score, and recurrence rate. We can conclude that cutting hybrid seton placement with tube drainage was an effective procedure and valid alternative for complex anorectal fistula with a favorable result on higher healing rate, less postoperative pain, and few impact on the function of sphincter.