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.

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.

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.

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.

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。

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.

The Elist Drain Retainer: A New Adherent Drain Retainer with Antibacterial Properties

Background: Surgical drains are used in at least half of all surgical operations world-wide. The gold standard for the fixation of drains to the skin is currently the “Roman garter” (RG) technique, which involves knotting a suture around the drain. Its disadvantages include the time to perform the technique, possible loosening and accidental removal, and bacterial infection with biofilm formation if left in place for weeks. Methods: The Elist Drain Retainer (EDR) has been developed, and it consists of a short plastic tube bent to 90° with a side slit for the drain, fixed to a mounting patch with adhesive and an antiseptic. Results: In a clinical trial comparing 25 drain attachments with the RG versus 25 drain attachments with the new EDR, the former took an average of five minutes and the EDR took an average of one minute to place. Loosening occurred in five (20%) drains and accidental removal occurred in four (16%) for the RG group versus no incidences of loosening or accidental removal in the EDR group. Self-removal of the EDR was possible for seven (28%) patients. Conclusion: The EDR demonstrated a clear advantage over the RG in all tested parameters. The lack of instruments and the possibility of self-removal of the EDR when a drain is needed are particularly advantageous features.

On the Same Floor Building Drainage Technology

The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe （sewage and branch pipes respectively） which can be into other houses without going through floors! This technology has many advantages, like easy to construct and install at the same floor on one hand; on the other hand, when sewage or waste reach the top compared with the same kind drainage systems and other drainage methods, it can smoothly enter the main pipe （the chief vertical one）. Moreover, once there is any situation needing dredge and cleaning, this problem can be solved at the same floor without interrupting the lives of other families. Last but not the least, it is so convenient to create a clean and tidy washing room. The branch pipe without being through floors is the very reason to solve the problem of surface condensation relative to sewage pipe in the rainy days, which correspondingly increases the hcight of head room indoor, is more favorable for fire prevention and much easier to keep smooth pipe flow.

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.

Visualization of drained rock volume(DRV) in hydraulically fractured reservoirs with and without natural fractures using complex analysis methods(CAMs)

The drainage areas(and volumes)near hydraulically fractured wells,computed and visualized in our study at high resolution,may be critically affected by the presence of natural fractures.Using a recently developed algorithm based on complex analysis methods(CAMs),the drained rock volume(DRV)is visualized for a range of synthetic constellations of natural fractures near hydraulic fractures.First,flow interference effects near a single hydraulic fracture are systematically investigated for a variety of natural fracture sets.The permeability contrast between the matrix and the natural fractures is increased stepwise in order to better understand the effect on the DRV.Next,a larger-scale model investigates flow interference for a full hydraulically fractured well with a variety of natural fracture sets.The time of flight contours(TOFCs)outlining the DRV are for all cases with natural fractures compared to a base case without any natural fractures.Discrete natural fractures,with different orientations,hydraulic conductivity,and fracture density,may shift the TOFC patterns in the reservoir region drained by the hydraulically fractured well,essentially shifting the location of the well’s drainage area.The CAM-based models provide a computationally efficient method to quantify and visualize the drainage in both naturally and hydraulically fractured reservoirs.

A general solution for vertical-drain consolidation with impeded drainage boundaries

An analytical solution is derived from the generalized governing equations of equal-strain consolidation with vertical drains under multi-ramp surcharge preloading. The hydraulic boundary conditions at both top and bottom of the consolidating soil are modelled as impeded drainage. The impeded drainage is described by using the third type boundary condition with a characteristic factor of drainage efficiency. Fully drained and undrained boundary conditions can also be modelled by applying an infinite and a zero characteristic factor, respectively. Simultaneous radial and vertical flow conditions are considered, together with the effects of drain resistance and smear. An increase in total stress due to multi-ramp loading is reasonably modelled as a function of both time and depth. A solution to calculate excess pore-water pressure at any arbitrary point in soil is derived, and the overall average degree of consolidation is obtained. It shows that the proposed solution can be used to analyze not only vertical-drain consolidation but also one-dimensional consolidation under either one-way or two-way vertical drainage conditions. The characteristic factors of drainage efficiency of top and bottom boundaries have a potentially important influence on consolidation. The boundary may be considered fully drained when the characteristic factor is greater than 100 and fully undrained when the characteristic factor is less than 0.1. The stress distribution along depth induced by the surcharge loading has a limited effect on the overall average degree of consolidation.

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。

Drainage Management Problems Evaluation: Case Study Baloza and EL-Farama Drains, North Sinai, Egypt

Drainage management activities aim at maintaining the performance of drainage networks by assessing the major drainage management problems regarding sedimentation, bank erosion, vegetation, water quality, and biodiversity, to find appropriate solutions for channel improvement in order to increase agricultural productivity and maintain agricultural land and the surrounding environment. In this research, we evaluate the drainage management problems to the surface drains Baloza and EL-Farama in the cultivated Tina Plain region (21,000 hectares) North Sinai, Egypt to provide an accurate data to help decision-makers to know the status of maintenance of the watercourses and the need for improvement. For this, Intensive field investigations were carried out regarding a hydrographic survey of the actual drains cross-section using total station and aqua sounder devices, visual stream bank erosion survey, and vegetation survey. In addition, monthly water samples from the drainage water were treated and analyzed for physical and chemical, bacteriological related indices. The results showed, the studied drains suffer from sedimentation, vegetation infection, and bank erosion in some reaches and need remedy. Estimated sedimentation in EL-Farama Drain was 34369 m3/year and in Baloza Drain 29153 m3/year;bank slope failures upstream and downstream pump stations were recorded;the average weed infection ratio for both drains was 30%. The results of water quality parameters showed acceptable concentrations for BOD, DO, NO3, and total coliform according to Egypt decree, 92/2013 for the protection of the Nile River and its waterways from pollution, except TDS (more than 10,000 mg/L). The drainage water was classified as high saline and it was unacceptable for irrigation. Therefore, the author recommends to remove sedimentation and vegetation every 2 years by mechanical methods, applying gabions lining to prevent bank erosion, and treating drainage water using wetland system and utilizing the treated wastewater in fish farming.

Prophylactic Wound Drainage in Orthopaedics: A Comparative Evaluation of Closed Suction Drainage versus No-Drainage in a Nigerian Teaching Hospital

Background: Surgical wound drainage is practiced routinely by many orthopaedic surgeons despite studies that challenge the practice. Among proponents, the advantages of drainage include prevention of haematoma and/or seroma formation which potentially reduces the chances for infection, prevention of wound swelling, prevention of compartment syndrome and improvement of the local wound environment. Opponents argue that prophylactic wound drainage confers no significant advantages, increases the risk of infection and the need for blood transfusion with the attendant risks of this therapy. Aim: To ascertain if prophylactic drainage of clean orthopaedic wounds confer any significant advantages by evaluating wound and systemic factors in two treatment groups. Patients and Methods: A prospective analysis of 62 patients was undergoing clean orthopaedic procedures. The patients were randomly assigned to a “No drain” (study) group and a “drain” (control) group. Each group had 31 patients. Surgeons were blinded to the randomization process and the evaluation of clinical outcomes. The parameters assessed included pain, superficial wound infection, the need for post-operative transfusion, wound leakage, dressing changes and the surgery-discharge interval. Data was analysed using SPSS statistics version 20 (IBM Corp., New York). Results: There were no significant differences in the demographic data. Femoral fractures were the commonest indication for surgery (43.55%), and plate and screw osteosynthesis was the commonest procedure (48.4% in the drain group and 67.7% in the no-drain group). There was a significantly higher need for post-operative transfusion in the drain group (22.6% against 0%) as well as a significantly prolonged capillary refill time (2.39 + 0.56 secs versus 2.03 + 0.41 secs). Although not statistically significant, there were four cases (12.8%) of superficial wound infection in the drain group and 1 case (3.2%) in the no-drain group. Conclusion: Prophylactic wound drainage confers no significant advantages over no drainage and may contribute to increased treatment costs through an increased post-operative transfusion requirements.

Eco-drainage Pond in Non Irrigated Land for the Conservation of Land and Water Based on Community Participation

There are some bad impacts from a critical land such as flood in rainy season and dryness in dry season. Long dryness could cause shortage of water for human consumption, industry and agriculture. Prevention has been made to avoid the both bad impacts by building hydraulic structures like reservoirs and ponds in order to reduce the peak flow during the rainy season and to store the water for use during the dry season. However, they gradually become full of sediment. This will make them work insufficiently and will cause high maintenance cost. Moreover, wells in agriculture field used as retention also suffer dryness to make crop failure. This study aims to develop a model of pond for conservation of land and water in non irrigated land. Community participation is crucial in order to solve the flood and dryness problems. The community, especially the farmers will participate actively in the implementation and maintenance of the model. There are benefits in using the pond model such as： （1） to control sediment transport to the rivers, reservoir or other hydraulic structures; （2） to reduce flood rate; （3） to increase ground water recharge; （4） to contain water for agriculture and （5） to control the fertility of land. The cost of making a unit of model （sedrainpond） of 1.5 m diameter and 1.5 meter depth is relatively cheap between $10 to $20 （US）, and the maintenance is done by the farmers. When the pond model becomes functional, besides containing water in the rainy season, the water can be used to sustain water for agriculture in the dry season to avoid any crop failure. When the pond becomes dry, the farmers can harvest the suspended load sediment such as clay or silt to spread onto their land to keep its fertility.

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。

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.

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.