Improving cross drain systems to minimize sediment delivery using GIS

A well developed network of roads must exist as a necessary infrastructure system in modem forestry to facilitate forest op- erations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model （as an extension of ArcGIS） was used to estimate sediment delivery and the distribution of a road network, given the exist- ing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were neg- atively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model.

Prophylactic intra-peritoneal drain placement following pancreaticoduodenectomy:A systematic review and metaanalysis

AIM:To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy(PD)with or without prophylactic drainage.METHODS:Relevant comparative randomized and nonrandomized studies were systemically searched based on specific inclusion and exclusion criteria.Postoperative outcomes were compared between patients with and those without routine drainage.Pooled odds ratios(OR)with 95%CI were calculated using either fixed effects or random effects models.RESULTS:One randomized controlled trial and four non-randomized comparative studies recruiting 1728patients were analyzed.Patients without prophylactic drainage after PD had significantly higher mortality(OR=2.32,95%CI:1.11-4.85;P=0.02),despite the fact that they were associated with fewer overall complications(OR=0.62,95%CI:0.48-0.82;P=0.00),major complications(OR=0.75,95%CI:0.60-0.93;P=0.01)and readmissions(OR=0.77,95%CI:0.60-0.98;P=0.04).There were no significant differences in the rates of pancreatic fistula,intraabdominal abscesses,postpancreatectomy hemorrhage,biliary fistula,delayed gastric emptying,reoperation or radiologic-guided drains between the two groups.CONCLUSION:Indiscriminate abandonment of intraabdominal drainage following PD is associated with greater mortality,but lower complication rates.Future randomized trials should compare routine vs selective drainage.

Is the measurement of drain amylase content useful for predicting pancreas-related complications after gastrectomy with systematic lymphadenectomy?

Many studies investigating postoperative pancreatic fistula(POPF)after gastrectomy,including studies measuring drain amylase content(D-AMY)as a predictive factor have been reported.This article reviews previous studies and looks to the future of measuring D-AMY in patients after gastrectomy.The causes of pancreatic fluid leakage are;the parenchymal and/or thermal injury to the pancreas,and blunt injury to the pancreas by compression and retraction.Measurement of D-AMY to predict POPF has become common in clinical practice after pancreatic surgery and was later extended to the gastric surgery.Several studies have reported associations between D-AMY and POPF after gastrectomy,and the high value of D-AMY on postoperative day(POD)1 was an independent risk factor.To improve both sensitivity and specificity,attempts have been made to enhance the predictive accuracy of factors on POD 1 as well as on POD 3 as combined markers.Although several studies have shown a high predictive ability of POPF,it has not necessarily been exploited in clinical practice.Many problems remain unresolved;ideal timing for measurement,optimal cut-off value,and means of intervention after prediction.Prospective clinical trial could be imperative in order to develop D-AMY measurement in common clinical practice for gastric surgery.

Control of Seepage through Earth Dams Based on Pervious Foundation Using Toe Drainage Systems

Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h3), and the coordinates of the free surface (hx). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (Hd) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.

Semi-analytical solution for drained expansion analysis of a hollow cylinder of critical state soils

The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers.

Palliative long-term abdominal drains vs large volume paracenteses for the management of refractory ascites in end-stage liver disease

BACKGROUND Long-term abdominal drains(LTAD)are a cost-effective palliative measure to manage malignant ascites in the community,but their use in patients with end-stage chronic liver disease and refractory ascites is not routine practice.The safety and cost-effectiveness of LTAD are currently being studied in this setting,with preliminary positive results.We hypothesised that palliative LTAD are as effective and safe as repeat palliative large volume paracentesis(LVP)in patients with cirrhosis and refractory ascites and may offer advantages in patients’quality of life.AIM To compare the effectiveness and safety of palliative LTAD and LVP in refractory ascites secondary to end-stage chronic liver disease.METHODS A retrospective,observational cohort study comparing the effectiveness and safety outcomes of palliative LTAD and regular palliative LVP as a treatment for refractory ascites in consecutive patients with end-stage chronic liver disease followed-up at our United Kingdom tertiary centre between 2018 and 2022 was conducted.Fisher’s exact tests and the Mann-Whitney U test were used to compare qualitative and quantitative variables,respectively.Kaplan-Meier survival estimates were generated to stratify time-related outcomes according to the type of drain.RESULTS Thirty patients had a total of 35 indwelling abdominal drains and nineteen patients underwent regular LVP.The baseline characteristics were similar between the groups.Prophylactic antibiotics were more frequently prescribed in patients with LTAD(P=0.012),while the incidence of peritonitis did not differ between the two groups(P=0.46).The incidence of acute kidney injury(P=0.014)and ascites/drain-related hospital admissions(P=0.004)were significantly higher in the LVP group.The overall survival was similar in the two groups(log-rank P=0.26),but the endpoint-free survival was significantly shorter in the LVP group(P=0.003,P<0.001,P=0.018 for first ascites/drain-related admission,acute kidney injury and drain-related complications,respectively).CONCLUSION The use of LTAD in the management of refractory ascites in palliated end-stage liver disease is effective,safe,and may reduce hospital admissions and utilisation of healthcare resources compared to LVP.

Recent evidence for subcutaneous drains to prevent surgical site infections after abdominal surgery:A systematic review and metaanalysis

BACKGROUND Surgical site infections(SSIs)increase mortality,hospital stays,additional medical treatment,and medical costs.Subcutaneous drains prevent SSIs in gynecological and breast surgeries;however,their clinical impact in abdominal surgery remains unclear.AIM To investigate whether subcutaneous drains were beneficial in abdominal surgery using a systematic review and meta-analysis.METHODS The database search used PubMed,MEDLINE,and the Cochrane Library.The following inclusion criteria were set for the systematic review:(1)Randomized controlled trial studies comparing SSIs after abdominal surgery with or without subcutaneous drains;and(2)Studies that described clinical outcomes,such as SSIs,seroma formation,the length of hospital stays,and mortality.RESULTS Eight studies were included in this meta-analysis.The rate of total SSIs was significantly lower in the drained group(54/771,7.0%)than in the control group(89/759,11.7%),particularly in gastrointestinal surgery.Furthermore,the rate of superficial SSIs was slightly lower in the drained group(31/517,6.0%)than in the control group(49/521,9.4%).No significant differences were observed in seroma formation between the groups.Hospital stays were shorter in the drained group than in the control group.CONCLUSION Subcutaneous drains after abdominal surgery prevented SSIs and reduced hospital stays but did not significantly affect seroma formation.The timing of drain removal needs to be reconsidered in future studies.

Modelling smear effect of vertical drains using a diameter reduction method

Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.

Experimental and numerical modeling on vacuum consolidation behavior of staged-filled soil slurry with prefabricated horizontal drain and flocculant

The vacuum-assisted prefabricated horizontal drain offers a promising method for strengthening soil slurry,allowing simultaneous filling and vacuum-dewatering via staged construction.However,there is limited research on the unique characteristics of staged filling.This study aims to investigate the vacuum consolidation process of staged-filled soil slurry through laboratory model tests and numerical simulations,also assessing the impact of anionic polyacrylamide.Comparative analyses are conducted between vacuum consolidation with and without anionic polyacrylamide,as well as self-weight consolidation without anionic polyacrylamide.Results reveal contour lines of excess pore pressure,water content,and soil strength forming an ellipse around the prefabricated horizontal drain board.During the consolidation process,a higher degree of consolidation,lower water content,and higher soil strength were observed closer to the prefabricated horizontal drain board.After treatment,the uppermost filling layer exhibits an average water content that was approximately 40%higher than the lower filling layer,and its average strength was about 60%lower.This discrepancy is primarily due to the absence of sealing on the top surface and the relatively short vacuum consolidation time caused by staged filling.The introduction of anionic polyacrylamide-induced flocculation significantly improves the initial consolidation rate but minimally affects the dewatering capacity of vacuum preloading.Using flocculant can enhance both the staged filling rate and soil strength(by 1e2 times).Additionally,employing a staggered arrangement between different prefabricated horizontal drain layers is advisable to prevent top-down penetration in areas with low soil strength.

RESIDENTIAL DRAIN WATER HEAT RECOVERY SYSTEMS: MODELING, ANALYSIS, AND IMPLEMENTATION

This paper describes the design and environmental improvements that can be achieved using drain water heat recovery systems(DWHR)to reduce the energy consumption associated with residential showering.DWHR systems transfer heat from hot drain water to the shower’s incoming cold water stream,thus reducing the demand on the hot water heater.There are various DWHR systems available that differ in heat exchanger type,cost,and performance.This article focuses on designing a flat plate and gravity fed heat exchangers for a range of residential showering conditions.This is useful since there currently is no peer-reviewed published data on the effectiveness of DWHR,nor is there published research considering the emissions reductions that can be achieved with realistic DWHR systems.The governing equations for heat exchangers are used to model empirical data and to derive implementation recommendations for DWHR design.The model is validated using a prototype flat plate heat exchanger and test stand under varying flow rates and temperatures.A Monte Carlo simulation of the results showed that DWHR could save an average$74 a year for homes with natural gas water heaters and$160 a year for homes with electric water heaters.This corresponds to 0.3 metric tons and 1.5 metric tons of CO_(2) offset per home per year for natural gas and electric water heaters,respectively.The results are compiled and organized into a software program that allows consumers to input their household showering habits and location to get an estimate of their CO_(2),energy,and cost savings to determine if they should install a DWHR system.

Special stent for draining the abdominal abscess respectively from colon and duodenum:A case report

BACKGROUND Postoperative abdominal infections are an important and heterogeneous health challenge.Many samll abdominal abscesses are resolved with antibiotics,but larger or symptomatic abscesses may require procedural management.CASE SUMMARY A 65-year-old male patient who suffered operation for the left hepatocellular carcinoma eight months ago,came to our hospital with recurrent abdominal pain,vomit,and fever for one month.Abdominal computed tomography showed that a big low-density dumbbell-shaped mass among the liver and intestine.Colonoscopy showed a submucosal mass with a fistula at colon of liver region.Gastroscopy showed a big rupture on the submucosal mass at the descending duodenum and a fistula at the duodenal bulb.Under colonoscopy,the brown liquid and pus were drained from the mass with“special stent device”.Under gastroscopy,we closed the rupture of the mass with a loop and six clips for purse stitching at the descending duodenum,and the same method as colonoscopy was used to drain the brown liquid and pus from the mass.The symptom of abdominal pain,vomit and fever were relieved after the treatment.CONCLUSION The special stent device could be effectively for draining the abdominal abscess respectively from colon and duodenum.

基于Drain3与Loganomaly的网络安全日志分析与事件响应

随着信息技术的发展,网络安全问题日益凸显,为了保障网络系统的稳定运行,对HDFS-v1日志进行研究。首先,利用Drain3算法对日志进行解析,有效避免了构造深度较大、不平衡的树,实验结果显示其精确率、召回率、F1度量及准确度均高达100%;其次,基于Loganomaly算法进行异常检测,训练结果训练集、验证集损失值分别为0.21、0.18,预测结果精确度为96.889%,召回率为93.604%,F1度量为95.218%;接着,再用Drain3算法对异常日志分类;最后,通过远程控制实现异常事件响应,发送报警邮件,确保在HDFS发生紧急情况时能够快速、有效地处理故障,保障大数据处理任务的稳定进行。

Study of the Efficiency of Vertical Drains by an FEM Method in Soil Treatment for Road Projects: Case of the Development and Bitumination Works of the ROCADE Porto-Novo in Benin

This article aims to study the efficiency of coupled vertical drains for the treatment of long-lasting compressible clay soils for the road project platform of the ring road of Porto Novo, capital of Benin. The experimental data allowed us to estimate a consolidation of 29% in 9 months, justifying the drainage of the soil. In order to study the efficiency of drainage, a FEM model was proposed simulating different scenarios. These include a drainless road, pavements equipped with vertical drains with meshes of 0.5 m 0.5 m, 1 m 1 m and 1.5 m 1.5 m respectively and horizontal drains. The results expressed in terms of variations in vertical stresses, effective stresses and shear deformations revealed significant variations in pavement performance depending on the mesh size of the vertical drains. The configuration with a mesh of 0.5 m 0.5 m showed the least deformations, thus indicating a reduction in deformations and better stress distribution. However, the other mesh configurations showed variable results, underlining the importance of choosing the right mesh for the specific project conditions.

Coupling Aquaculture—Crop Productions and Using of Water Drained from Ponds Rearing Clarias gariepinus as Fertilizer for Okra Production (Abelmoschus esculentus var. Clemson spineless, L. Moench)

The present study concerns the revalorization of drained water from aquaculture ponds rearing Clarias gariepinus on okra crops. The rearing was carried out at the farm of Gaston Berger University in 100 m2 ponds. In each pond, the individuals of C. garipinus with an average weight of 6 ± 0.3 g were stocked at a density of 11 per m2. The water temperature and pH were measured during the experiment. The control fishing is carried out every month to monitor variations in the weight and size of reared individuals. The plant production is carried out in elementary plots measuring 3 m × 1.5 m. Each plot was fertilized with either: drained water from C. gariepinus rearing (DWC), poultry droppings (PD), cow dung (CD) and mineral fertilizer (NPK). Treatments are carried out in tripliqua with either river water (RW), RW + the recommended dose of NPK (RD-NPK), RW + RD-PD, RW + RD-CD, DWC, DWC + 25% RD-NPK, DWC + 50% RD-NPK, DWC + 75% RD-NPK, DWC + 25% RD-PD, DWC + 50% RD-PD, DWC + 75% RD-PD, DWC + 25% RD-CD, DWC + 50% RD-CD, DWC + 75% RD-CD. Growth parameters and yield of okra were determined. The average temperature in the rearing environment was 27.6 ± 1.5˚C and pH 7.9 ± 1.1. After six (06) months of rearing, C. gariepinus individuals reached an average weight of 850.12 ± 1.3 g and an average height of 52.44 ± 1.1 cm. The daily weight gain and specific growth rates over this period were 3.9 g per day and 2.8% per day, respectively. The treatment T1 (RW + DR-NPK) gave the highest mean collar diameter and mean plant height with 2.3 ± 0.9 cm and 61.6 ± 32 cm, respectively. In T4 (DWC), the mean height of plants was 38.8 ± 23.5 cm and mean collar diameter 1.4 ± 0.8 cm. The growth performance in T4 was comparable to that of RD-CD (T3), but different from RD-NPK (T1) and RD-PD (T2). The highest average number, average weight, average length and average diameter of fruits were noted in treatments T13 (RW + RD-75%CD) and T7 (DWC + 75% RD-NPK). The best yields were noted in T1 (RW + RD-NPK) = 10.8 ± 5.4 t·ha−1, T5 (DWC + 25% RD-NPK) = 9.2 ± 4.6 t·ha−1 and T4 (DWC) = 8.6 ± 4.3 t·ha−1 which are comparable and higher than those obtained in T2 = 5.7 ± 2.8 t·ha−1 and T3 = 7.5 ± 3.8 t·ha−1.

隧道涌水量基于MODFLOW中DRAIN模块水力传导系数取值探析

目前Visual Modflow已广泛地应用于隧道涌水的模拟,Drain模块中的水力传导系数是一个综合系数,但没有可参考的取值范围。从排水沟水力传导系数对隧洞涌水量引起的变化入手,通过C值的不同取值范围,利用模型计算出的涌水量与真实涌水量进行对比,发现当水力传导系数取值在一定范围内时计算出的涌水量最接近施工时隧道的真实涌水量,以此为Drain模块中水力传导系数的取值作一个经验参考。

新型Drain Box设计与应用

本文首先介绍了目前国内海上油气田设施开排系统设计的工艺设计流程的原理及应用特点,随后通过对比分析介绍了一种新型DrainBox的设计与运用,最后对该新型DrainBox的创新点进行了分析和介绍,并对其推广与应用前景进行了展望。

A new concept of backfll design—Application of wick drains in backflled stopes

Backflling represents an environmentally friendly mining waste disposal technique.It is increasingly used in underground mines all over the world.However,its primary purpose remains to improve ground stability and to reduce ore dilution.Previous investigations have shown that fll drainage plays a key role in backfll and barricade design.With a poor drainage system in the backflled stope,the required dimension of barricade,which is constructed at the base of the stope near the drift entrance,has to be increased.A poor backfll drainage system can also lead to a signifcant increase in drainage waiting time and further reduction in mining productivity.In this paper,the drainage of conventional backfll design in backflled stopes is briefly reviewed.For the frst time,the application of the wick drain is introduced in the backfll within mine stopes.The drainage improvement from the introduction of the wick drain is illustrated using numerical modeling.

Drain amylase value as an early predictor of pancreatic fistula after cephalic duodenopancreatectomy

AIM: To determine predictors of clinically relevant pancreatic fistulas (CRPF) by measuring drain fluid amylase (DFA) in the early postoperative period.

FREEZE PROFILE AND HEAT BALANCE CALCULATION OF THE 160kA DRAINED CELL

A 2D full cell thermo-electric model of 160kA drained cell was set up using finiteelement code to calculate its freeze profile, then the drained cell model was modifiedaccording to the freeze profile computed and its heat balance was calculated. Comparedwith that of a 160kA conventional Hall-Heroult cell (H-H cell), though the melts vol-ume of the drained cell reduced greatly, the whole heat loss from it didn't drop downapparently, and an analysis was presented in the paper. On the other hand, the anode-cathode distance (ACD) of a drained cell was much less than that of a H-H cell, sothe voltage drop on it and heat produced decreased too, steps should be taken to keepa workable heat balance on a drained cell.

Drainage by urostomy bag after blockage of abdominal drain in patients with cirrhosis undergoing hepatectomy

Abdominal drainage was previously recommended as a post-hepatectomy procedure for patients with cirrhosis.This report introduces a simple technique that prevents leakage of ascitic fluid after cirrhotic hepatectomy complicated by blockage of the abdominal drain.In 59 patients who had had cirrhotic hepatectomy complicated by leakage of ascites in the drain site after drainage removal between January 2001 and April 2011,31 underwent suture ligation(sutured group) and 28 were given urostomy bag at the abdominal drainage site(drainage group).The mean length of postoperative hospital stay in the drainage group was shorter than in the sutured group(16.11±2.61 vs 34.23±4.86 days,P=0.000).Meanwhile,the drainage group showed decreased postoperative complications,including leakage of ascites,wound infection,and collection of ascites.Drainage by urostomy bag can prevent prolonged leakage of ascitic fluid after the blockage of abdominal drains in patients undergoing cirrhotic hepatectomy.