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Lateral earth pressure of granular backfills on retaining walls with expanded polystyrene geofoam inclusions under limited surcharge loading 被引量:1
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作者 Kewei Fan Guangqing Yang +2 位作者 Weilie Zou Zhong Han Yang Shen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1388-1397,共10页
Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,t... Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model tests.The testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge loading.The distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge loading.An approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests. 展开更多
关键词 Retaining wall expanded polystyrene(EPS)geofoam Limited surcharge loading Lateral earth pressure Model test Prediction
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Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology
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作者 İsmail Cem Akgün Çağın Bolat Ali Gökşenli 《China Foundry》 SCIE EI CAS CSCD 2024年第1期60-70,共11页
In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollu... In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollution.At this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a problem-solver.Owing to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors nowadays.In this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF studies.Additionally,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive responses.Attained results show that PEC particles can be an alternative to expensive hollow spheres used in the previous works.Besides,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength. 展开更多
关键词 die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation
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Expandable endoprostheses in skeletally immature patients:Where we are
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作者 RecepÖztürk 《World Journal of Orthopedics》 2024年第4期312-317,共6页
Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990... Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990s,the treatment options for these patients were rotationplasty or amputation.Multimodal approaches that combine imaging,chemotherapy,and surgical techniques have enabled the development of limb-preserving methods with satisfactory results.In order to overcome inequality problems,expandable prostheses have been developed in the 1980s.Extendable endoprosthesis replacements have been improved over the years and are now an established and safe alternative.Noninvasive prostheses appear to be advantageous compared to minimally invasive expandable prostheses that require multiple surgical procedures,but the complication rate remains high.Therefore,although expandable prostheses are not the definitive answer to the treatment of bone sarcomas in skeletally immature children,they are still a suitable interim choice until full adulthood is achieved.Due to reported high complication rates,the procedures require significant experience and are recommended for use only in specialized cancer centers. 展开更多
关键词 Bone sarcoma expandable endoprostheses Limb salvage surgery NONINVASIVE Minimal-invasive INVASIVE Extendible endoprostheses
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Nursing Care and Causative Analysis of Grade IV Capsular Contracture Following Breast Cancer Expander Implantation
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作者 Rong Chen Nan Zhang Huiting Zhang 《Advances in Breast Cancer Research》 CAS 2024年第1期1-9,共9页
Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reason... Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reasons for the formation of capsular contracture after Stage I expander implantation and prevent its recurrence following Stage II reconstruction. Methods: In May 2020, the patient noticed an increase in the size of a breast mass. In August, she underwent AC-THP neoadjuvant chemotherapy, followed by a “right breast-conserving nipple-areolar subglandular excision + right axillary lymph node dissection + expander implantation” surgery in November 2020. Radiation therapy began in January 2021. During radiation therapy, the patient experienced severe breast hardening, distortion, tenderness, and was diagnosed with Grade IV capsular contracture. To relieve the capsular contracture, the patient underwent a “contracted capsule incision and release procedure + removal of the right breast expander + right breast implantation” surgery in July 2021. Postoperatively, measures were taken to prevent incision infection, emphasizing aseptic techniques, ensuring smooth negative pressure drainage, reducing skin flap tension, monitoring skin flap blood supply, actively preventing subcutaneous effusion and hematoma, and applying appropriate compression dressings. Results: The patient was discharged after the removal of the drainage tube. During the postoperative follow-up at 3 and 6 months, there was no recurrence of capsular contracture, and the breast appeared full, upright, and relatively soft. There were no complications such as hematoma, infection, breast implant rupture, breast sagging, or displacement. The patient had a good outcome without additional financial or surgical burdens. Conclusion: The occurrence of Grade IV capsular contracture in the patient is generally related to infection after Stage I expander implantation, improper compression dressing, excessive saline injection causing content infiltration, and radiation therapy. Therefore, it is recommended to enhance the intraoperative and postoperative prophylactic use of antibiotics after Stage I expander implantation. Intermittent saline injection after surgery, with the amount of saline gradually increasing rather than filling all at once, is advisable. This helps the breast tissue gradually adapt to expansion, reducing the risk of capsular contracture. Postoperatively, patients should be instructed to wear pressure garments and breast elastic bandages while intensifying breast monitoring during radiation therapy and increasing postoperative follow-up. 展开更多
关键词 Breast Cancer Capsular Contracture expander Implantation
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Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures
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作者 Chee Lim Jonathan Ng +4 位作者 Babak Sarraf Rhys Vaughan Marios Efthymiou Leonardo Zorron Cheng Tao Pu Sujievvan Chandran 《World Journal of Transplantation》 2024年第2期88-98,共11页
BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on s... BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures. 展开更多
关键词 Liver transplantation CHOLANGIOPANCREATOGRAPHY Endoscopic retrograde CONSTRICTION PATHOLOGIC Self expandable metallic stents Bile duct diseases CHOLESTASIS
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The expanding amyloid family:Structure,stability,function,and pathogenesis
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作者 Michael R Sawaya 《四川生理科学杂志》 2024年第1期106-106,共1页
The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack int... The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack into unbranched fibrils.Stranger still,a single protein sequence can adopt wildly different two-dimensional conformations,yielding distinct fibril polymorphs. 展开更多
关键词 AMYLOID PATHOGENESIS expandING
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Efficacy and safety of standard and anti-reflux self-expanding metal stent: A systematic review and meta-analysis of randomized controlled trials 被引量:2
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作者 Sudha Pandit Hrishikesh Samant +1 位作者 James Morris Steven J Alexander 《World Journal of Gastrointestinal Endoscopy》 CAS 2019年第4期271-280,共10页
BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer ... BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux.AIM To compare the standard and the anti-reflux stents in terms of their efficacy,safety, and complications.METHODS The meta-analysis included 8 randomized clinical trials(RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding.RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference(SMD):-0.33(-0.71, 0.05); P = 0.09, I2: 37%]. There was no statistical difference in the gastrointestinal reflux(GER) scores between the two types of stents [SMD:-0.17(-0.78, 0.45); P = 0.008, I2: 74%]. Compared to standard stent,anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37(0.66, 2.83); P = 0.40, I2: 0 %], bleeding [OR: 1.43(0.40, 5.13); P = 0.59, I2: 0 %], and obstruction [OR: 1.66(0.60, 4.60); P = 0.33, I2: 0 %].CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications. 展开更多
关键词 Self expandING metal STENT Anti-reflux STENT RANDOMIZED controlled trial ESOPHAGEAL STENT META-ANALYSIS
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An Expanded Optimal Control Policy for a Coupled Tanks System with Random Disturbance 被引量:1
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作者 Sie Long Kek Sy Yi Sim Chuei Yee Chen 《Advances in Pure Mathematics》 2019年第4期317-329,共13页
In this paper, an expanded optimal control policy is proposed to study the coupled tanks system, where the random disturbance is added into the system. Since the dynamics of the coupled tanks system can be formulated ... In this paper, an expanded optimal control policy is proposed to study the coupled tanks system, where the random disturbance is added into the system. Since the dynamics of the coupled tanks system can be formulated as a nonlinear system, determination of the optimal water level in the tanks is useful for the operation decision. On this point of view, the coupled tanks system dynamics is usually linearized to give the steady state operating height. In our approach, a model-based optimal control problem, which is adding with adjusted parameters, is considered to obtain the true operating height of the real coupled tanks system. During the computation procedure, the differences between the real plant and the model used are measured repeatedly, where the optimal solution of the model used is updated. On this basis, system optimization and parameter estimation are integrated. At the end of the iteration, the iterative solution approximates to the correct optimal solution of the original optimal control problem, in spite of model-reality differences. In conclusion, the efficiency of the approach proposed is shown. 展开更多
关键词 expanded Optimal Control COUPLED Tanks system Model-Reality DIFFERENCES ITERATIVE Solution Adjusted PARAMETERS
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A subspace expanding technique for global zero finding of multi-degree-of-freedom nonlinear systems
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作者 Zigang LI Jun JIANG +1 位作者 LingHONG J.Q.SUN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2020年第5期769-784,共16页
A subspace expanding technique(SET) is proposed to efficiently discover and find all zeros of nonlinear functions in multi-degree-of-freedom(MDOF) engineering systems by discretizing the space into smaller subdomains,... A subspace expanding technique(SET) is proposed to efficiently discover and find all zeros of nonlinear functions in multi-degree-of-freedom(MDOF) engineering systems by discretizing the space into smaller subdomains, which are called cells. The covering set of the cells is identified by parallel calculations with the root bracketing method. The covering set can be found first in a low-dimensional subspace, and then gradually extended to higher dimensional spaces with the introduction of more equations and variables into the calculations. The results show that the proposed SET is highlyefficient for finding zeros in high-dimensional spaces. The subdivision technique of the cell mapping method is further used to refine the covering set, and the obtained numerical results of zeros are accurate. Three examples are further carried out to verify the applicability of the proposed method, and very good results are achieved. It is believed that the proposed method will significantly enhance the ability to study the stability, bifurcation,and optimization problems in complex MDOF nonlinear dynamic systems. 展开更多
关键词 spatial discretization subspace expanding technique(SET) parallel computing subdivision global zero finding
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Experimental study on thermal and mechanical properties of tailings-based cemented paste backfill with CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials 被引量:1
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作者 Xiaoyan Zhang Tianrun Cao +3 位作者 Lang Liu Baoyun Bu Yaping Ke Qiangqiang Du 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第2期250-259,共10页
CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the ... CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the CPB with CEV added was prepared,and the specific heat capacity,thermal conductivity,and uniaxial compressive strength(UCS)of CPB with different cement-tailing ratios and CEV addition ratios were tested,the influence of the above variables on the thermal and mechanical properties of CPB was analyzed.The results show that the maximum encapsulation capacity of expanded vermiculite for CaCl_(2)·6H_(2)O is about 60%,and the melting and solidification enthalpies of CEV can reach 98.87 J/g and 97.56 J/g,respectively.For the CPB without CEV,the specific heat capacity,thermal conductivity,and UCS decrease with the decrease of cement-tailing ratio.For the CPB with CEV added,with the increase of CEV addition ratio,the specific heat capacity increases significantly,and the sensible heat storage capacity and latent heat storage capacity can be increased by at least 10.74%and 218.97%respectively after adding 12%CEV.However,the addition of CEV leads to the increase of pores,and the thermal conductivity and UCS both decrease with the increase of CEV addition.When cement-tailing ratio is 1:8 and 6%,9%,and 12%of CEV are added,the 28-days UCS of CPB is less than 1 MPa.Considering the heat storage capacity and cost price of backfill,the recommended proportion scheme of CPB material presents cement-tailing ratio of 1:6 and 12%CEV,and the most recommended heat storage/release temperature cycle range of CPB with added CEV is from 20 to 40℃.This work can provide theoretical basis for the utilization of heat storage backfill in green mines. 展开更多
关键词 CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials cemented paste backfill thermal property mechanical property
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Endoscopic transluminal pancreatic necrosectomy using a self-expanding metal stent and high-flow water-jet system 被引量:10
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作者 István Hritz Roland Fejes +5 位作者 András Székely Iván Székely László Horváth gnes Sárkány ron Altorjay László Madácsy 《World Journal of Gastroenterology》 SCIE CAS 2013年第23期3685-3692,共8页
Walled-off pancreatic necrosis and a pancreatic abscess are the most severe complications of acute pancreatitis. Surgery in such critically ill patients is often associated with significant morbidity and mortality wit... Walled-off pancreatic necrosis and a pancreatic abscess are the most severe complications of acute pancreatitis. Surgery in such critically ill patients is often associated with significant morbidity and mortality within the first few weeks after the onset of symptoms. Minimal invasive approaches with high success and low mortality rates are therefore of considerable interest. Endoscopic therapy has the potential to offer safe and effective alternative treatment. We report here on 3 consecutive patients with infected walled-off pancreatic necrosis and 1 patient with a pancreatic abscess who underwent direct endoscopic necrosectomy 19-21 d after the onset of acute pancreatitis. The infected pancreatic necrosis or abscess was punctured transluminally with a cystostome and, after balloon dilatation, a non-covered self-expanding biliary metal stent was placed into the necrotic cavity. Following stent deployment, a nasobiliary pigtail catheter was placed into the cavity to ensure continuous irrigation. After 5-7 d, the metal stent was removed endoscopically and the necrotic cavity was entered with a therapeutic gastroscope. Endoscopic debridement was performed via the simultaneous application of a high-flow water-jet system; using a flush knife, a Dormia basket, and hot biopsy forceps. The transluminal endotherapy was repeated 2-5 times daily during the next 10 d. Supportive care included parenteral antibiotics and jejunal feeding. All patients improved dramatically and with resolution of their septic conditions; 3 patients were completely cured without any further complications or the need for surgery. One patient died from a complication of prolonged ventilation severe bilateral pneumonia, not related to the endoscopic procedure. No procedure related complications were observed. Transluminal endoscopic necrosectomy with temporary application of a self-expanding metal stent and a high-flow water-jet system shows promise for enhancing the potential of this endoscopic approach in patients with walled-off pancreatic necrosis and/or a pancreatic abscess. 展开更多
关键词 Acute NECROTIZING pancreatitis Walled off PANCREATIC necrosis ENDOSCOPIC NECROSECTOMY Selfexpanding metal stent Water-jet system
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Determination of the load bearing capacity of pre-stressed expandable props for ground support in underground mines
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作者 Kunmeng Li Kaiyuan Jiang +3 位作者 Yuanhui Li Xin Wang Kai Liu Shuai Xu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第8期977-990,共14页
This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the... This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the expandable device could have much higher strength(>89 MPa)by laboratory tests,and the load bearing capacity of the expandable prop may depend on the stability of the supporting steel pipe structure.A good agreement was found between the laboratory test and numerical results in terms of the load bearing capacity and the final macro-bending failure pattern for expandable props with heights of 1.5 and 2.7 m,and the theoretical calculation for the strength of traditional steel structures is not directly suitable for the expandable props.Moreover,additional numerical simulations were performed for the expandable props with different normalized slenderness ratiosλ_(n)and loading eccentric distances e.The variation of stability coefficient of the expandable prop is in line with the Perry-Robertson equation and its correlation coefficients are fitted as a of 0.979 and b of 0.314.For estimating the load bearing capacity of the expandable props,the strength equation for traditional steel structures is improved by introducing a bending magnification factor and by modifying the normalized slenderness ratio to a converted slenderness ratio.Based on the underground field monitoring for the strength of expandable props with different heights,the empirical eccentric distances were back calculated,and a safety factor is introduced to obtain the designed strength of the expandable prop.In addition,a four-step design procedure is proposed for the expandable prop. 展开更多
关键词 Pillar stability Load bearing capacity expandable prop Slenderness ratio Eccentric distance
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Study on Load Bearing Characteristics of Novel Expandable Deepwater Drilling Conductor Based on Laboratory Experiment and Field Test
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作者 ZHANG Ming-he YANG Jin +2 位作者 YANG Yu-xiang XU Dong-sheng ZHOU Yi-su 《China Ocean Engineering》 SCIE EI CSCD 2023年第1期16-28,共13页
A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical ... A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical and lateral bearing capability of expandable conductors was depicted based on the ultimate subgrade reaction method and pile foundation bearing theory. The load-bearing characteristics of a laboratory-scale expandable conductor were analyzed through laboratory experiments. The serial simulation experiments are accomplished to study the bearing characteristics(vertical ultimate bearing capacity, lateral soil pressure, and lateral displacement) during the conductor soaking process. The laboratory experimental results show that the larger the length and thickness of expandable materials are,the higher the bearing capacity of the wellhead will be. During the conductor soaking process, the soil pressure around the three expandable conductors increases faster, strings representing a stronger squeezing effect and resulting in higher vertical bearing capacity. Furthermore, the lateral displacement of novel expandable conductor is smaller than that of the conventional conductor. All the advantages mentioned above contributed to the reduction of conductor’s jetting depth and soaking time. Lastly, the application workflow of a novel expandable deep-water drilling conductor was established and the autonomous expandable conductor was successfully applied in the South China Sea with a significant reduction of conductor’s jetting depth and soaking time. According to the soil properties and designed installation depth of the surface conductor, the arrangement of expandable materials should be designed reasonably to meet the safety condition and reduce the construction cost of the subsea wellhead. 展开更多
关键词 novel expandable surface conductor deep water subsea wellhead laboratory experiment field test
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Study on Sustained-Release Pesticides Blended with Fosthiazate-Stearic Acid/Expanded Perlite
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作者 Huimin Huang Zijun Wu +3 位作者 Zhijian Zhou Qiulin Xu Jie Yan Qiaoguang Li 《Journal of Renewable Materials》 SCIE EI 2023年第1期257-272,共16页
The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release con... The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary. 展开更多
关键词 expanded perlite FOSTHIAZATE stearic acid sustained release release kinetics
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Experimental study on lightweight expanded clay at particle level:Breakage of isolated grains
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作者 Elías Roces-Alonso Jose Estaire +1 位作者 Miriam Martín-Ruiz Jesús González-Galindo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第7期1846-1858,共13页
In this study,more than 1500 particles of lightweight expanded clay aggregate(LECA)are individually loaded up to breakage,following different patterns of contact(from 2 to 7)using a purpose-built apparatus.Consequentl... In this study,more than 1500 particles of lightweight expanded clay aggregate(LECA)are individually loaded up to breakage,following different patterns of contact(from 2 to 7)using a purpose-built apparatus.Consequently,a statistical model for predicting the number of fragments into which a grain breaks as a function of the number of contacts and their diameter is proposed.The number of fragments is found to follow a statistical binomial-type distribution function that depends on the number of contacts.In addition,a model based on Bayesian networks,capable of assessing the number of fragments and their size(measured as normalized weight)as a function of the number of contacts,is implemented.The proposed method is applicable when performing discrete element method(DEM)simulations on granular media in which grain breakage plays a relevant role. 展开更多
关键词 Lightweight expanded clay aggregate(LECA) Grain fragmentation Grain breakage Biaxial grain load
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ZnO-Embedded Expanded Graphite Composite Anodes with Controlled Charge Storage Mechanism Enabling Operation of Lithium-Ion Batteries at Ultra-Low Temperatures
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作者 Kun Ryu Michael J.Lee +1 位作者 Kyungbin Lee Seung Woo Lee 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期31-39,共9页
As lithium(Li)-ion batteries expand their applications,operating over a wide temperature range becomes increasingly important.However,the lowtemperature performance of conventional graphite anodes is severely hampered... As lithium(Li)-ion batteries expand their applications,operating over a wide temperature range becomes increasingly important.However,the lowtemperature performance of conventional graphite anodes is severely hampered by the poor diffusion kinetics of Li ions(Li^(+)).Here,zinc oxide(ZnO) nanoparticles are incorporated into the expanded graphite to improve Li^(+)diffusion kinetics,resulting in a significant improvement in lowtemperature performance.The ZnO-embedded expanded graphite anodes are investigated with different amounts of ZnO to establish the structurecharge storage mechanism-performance relationship with a focus on lowtemperature applications.Electrochemical analysis reveals that the ZnOembedded expanded graphite anode with nano-sized ZnO maintains a large portion of the diffusion-controlled charge storage mechanism at an ultra-low temperature of-50℃ Due to this significantly enhanced Li^(+)diffusion rate,a full cell with the ZnO-embedded expanded graphite anode and a LiNi_(0.88)Co_(0.09)Al_(0.03)O_(2)cathode delivers high capacities of 176 mAh g^(-1)at20℃ and 86 mAh g^(-1)at-50℃ at a high rate of 1 C.The outstanding low-temperature performance of the composite anode by improving the Li^(+)diffusion kinetics provides important scientific insights into the fundamental design principles of anodes for low-temperature Li-ion battery operation. 展开更多
关键词 diffusive and capacitive charge storages expanded graphite composites anode lithium-ion battery low-temperature operation transition metal oxide
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Current approach for Boerhaaves syndrome:A systematic review of case reports
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作者 Ippei Yamana Takahisa Fujikawa +1 位作者 Yuichiro Kawamura Suguru Hasegawa 《World Journal of Meta-Analysis》 2023年第4期112-124,共13页
There is no consensus on the appropriate therapeutic strategy for Boerhaave syndrome due to its rarity and changing therapeutic approaches.We conducted a systematic review of case reports documenting Boerhaave syndrom... There is no consensus on the appropriate therapeutic strategy for Boerhaave syndrome due to its rarity and changing therapeutic approaches.We conducted a systematic review of case reports documenting Boerhaave syndrome.AIM To assess the therapeutic methods and clinical outcomes and discuss the current trends in the management of Boerhaave syndrome.METHODS We searched PubMed,Google scholar,MEDLINE,and The Cochrane Library for studies concerning Boerhaave syndrome published between 2017 and 2022.RESULTS Of the included studies,49 were case reports,including a total of 56 cases.The mean age was 55.8±16 years old.Initial conservative treatment was performed in 25 cases,while operation was performed in 31 cases.The rate of conservative treatment was significantly higher than that of operation in cases of shock vital on admission(9.7%vs 44.0%;P=0.005).Seventeen out of 25 conservative cases(68.0%)were initially treated endoscopic esophageal stenting;2 of those 17 cases subsequently underwent operation due to poor infection control.Twelve cases developed postoperative leakage(38.7%),and 4 of those 12 cases underwent endoscopic esophageal stenting to stop the leakage.The length of the hospital stay was not significantly different between the conservative treatment and operation cases(operation vs conservation:33.52±22.69 vs 38.81±35.28 days;P=0.553).CONCLUSION In the treatment of Boerhaave syndrome,it is most important to diagnose the issue immediately.Primary repair with reinforcement is the gold-standard procedure.The indication of endoscopic esophageal stenting or endoluminal vacuum-assisted therapy should always be considered for patients in a poor general condition and who continue to have leakage after repair. 展开更多
关键词 Boerhaave syndrome Esophageal perforation Self expandable metalic stent Minimally invasive surgical procedures Anastomotic leakage Shock
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Optimizing Grids Demand Reduction through Enhanced Heat Transfer in Low-Temperature Waste Heat Driven ORC Systems
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作者 Cheng Wang Zizeng Gao 《Energy and Power Engineering》 2023年第12期457-467,共11页
With increasing awareness of energy conservation and environmental protection, the Organic Rankine Cycle (ORC) system has gained significant attention. This technology enables the recovery of industrial waste heat, wa... With increasing awareness of energy conservation and environmental protection, the Organic Rankine Cycle (ORC) system has gained significant attention. This technology enables the recovery of industrial waste heat, waste incineration heat, and renewable energy sources such as geothermal heat, biomass energy, and solar energy at lower temperatures. However, the low-grade heat source utilized in ORC systems faces a challenge to achieving high power generation efficiency and output power. Therefore, enhancing the power generation capacity of ORC systems is a key research focus in this field. An entranced heat exchanger ORC system with the screw expander driven by the low-temperature heat source is established to investigate the relevant performance. Hot water temperature from 77°C to 132°C is adopted for performance analysis, while the environmental temperature is approximately 25°C. Refrigerant R245fa is selected as the working fluid, and the screw expander is employed for power generation. It is worth noting that the entranced heat exchanger ORC system has significant potential for low-temperature heat recovery. Experimental results indicate that the maximum power output is 12.83 kW, which is obtained at around 105°C hot water inlet temperature. Correspondingly, the average power output remains 11.75 kW, revealing the system’s high stability for power generation. The implementation of a plate heat exchanger for enhanced heat transfer has enabled a 50% reduction in system size compared to traditional shell-tube type ORC systems. Besides, economic calculations demonstrate substantial benefits associated with the ORC system. The calculations indicate an internal benefit of 560,000 RMB/year, accompanied by notable external benefits such as an energy saving and emission reduction potential of up to 784 t CO2 per year. Moreover, the payback period is 2.23 years. It shows a remarkable improvement in terms of performance and excellent economic benefits. As a result, the novel ORC presents a promising alternative for low-grade heat utilization as compared to conventional small-scale ORC systems. 展开更多
关键词 ORC (Organic Rankine Cycle) Plate Heat Exchanger Screw expander Power Output Economic Analyse Energy Saving
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Even Closer China-Philippines Relations China and the Philippines have shown commitment to managing differences and expanding cooperation,which fosters more confidence in the ongoing stability of bilateral relations over the next six years
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作者 Dai Fan 《China Report ASEAN》 2023年第1期45-47,共3页
On January 3,2023,China welcomed the first visit in the new year by a foreign head of state,Philippine President Ferdinand Marcos Jr.The visit was also the president’s first official state visit to a country outside ... On January 3,2023,China welcomed the first visit in the new year by a foreign head of state,Philippine President Ferdinand Marcos Jr.The visit was also the president’s first official state visit to a country outside ASEAN since he took office in June 2022,which demonstrated the great importance the two countries attach to their bilateral relations.The three-day visit was fruitful despite a tight schedule. 展开更多
关键词 expandING visit BILATERAL
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Expanding Food Security
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作者 GODFREY OLUKYA 《ChinAfrica》 2023年第3期40-41,共2页
China and FAO assist Uganda to become self-sufficent in food production, and serve as the food basket of the region Eighty percent of Uganda’s economy depends on agriculture, according to the Uganda Bureau of Statist... China and FAO assist Uganda to become self-sufficent in food production, and serve as the food basket of the region Eighty percent of Uganda’s economy depends on agriculture, according to the Uganda Bureau of Statistics. For this reason, Frank Tumwebaze, Uganda’s minister of agriculture, animal industry and fisheries, said in an interview recently that since the majority of the country’s population is involved in agriculture. 展开更多
关键词 INTERVIEW AGRICULTURE expandING
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