An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we p...An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we propose a contour expansion scheme to construct rough paths. Different wiring features of the switchgear are used to connect rough local paths. All the paths are represented in a uniform data structure and forma path network. Finally, an improved A* algorithm is used to search the wiring path between the components in the routing network; the evaluation model is considered as heuristic rules for path searching. The result can satisfy the practical requirements of switchgear design. Experimental results are also provided.展开更多
This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data i...This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data interface response, and finally introduced the system wiring switchover function, and gave an example.展开更多
Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for ...Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.展开更多
Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harn...Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harness and the characteristics of wiring harness components, we established the model of wiring harness graph. Then we research the algorithm of identifying technology processes automatically, finally we describe the relationships between processes by introducing the constraint matrix, which is in or- der to lay a good foundation for harness process planning and production scheduling.展开更多
MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world le...MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world leading experts in her field of study and visited state-of-the-art laboratories during her first trip to China.展开更多
Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically orie...Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically oriented figure-of-8. Methods： We used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners, lnterfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. Results： Placement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% （p 〈 0.05, Tukey post ]hoc test）. On cyclic loading, all the constructs with vertical figure-of-eight but none with a horizontal construct failed （p = 0.01; Fisher＇s exact test）. Permanent fracture displacement after cyclic loading was ,57% lower with horizontal figure- of-eight constructs （p 〈 0.05; t test）. Conclusion： Placing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it f...This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it fully testable. The BIST resource insertion isguided by the results of symbolic testability analysis. It takes into consideration both BISTregister cost and wiring overhead in order to obtain the minimal area designs. A Simulated Annealingalgorithm is used to solve the overhead minimization problem. Experiments show that consideringwiring area during BIST synthesis results in smaller final designs as compared to the cases when thewiring impact is ignored.展开更多
Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact...Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact toughness and the tensile and flexuralstrengths of whole PWB with a laminated structure resultin great energy consumption and severe abrasion of thecutters during multi-level crushing.In addition,the hightemperatures occurring in continual crushing probablycause the decomposition of the polymer matrix.A thermalcrackmethod using residual steam as the heating mediumhas been developed to pre-treat waste PWBs.Thistreatment reduces the mechanical strength in order toimprove the recovery rate of valuable materials insubsequent mechanical recycling.The changes of thePWBs’macro-mechanical properties were studied toevaluate thermal expansion impacts associated withchanges in temperature,and the dynamic dislocationmicro-structures were observed to identify the fracturemechanism.The results showed that thermal cracking withsteam at the temperature of 500 K can effectively attenuatethe mechanical properties of waste PWBs,by reducing theimpact,tensile and flexural strengths respectively,by59.2%,49.3%and 51.4%,compared to untreated PWB.Thermal expansion can also facilitate the separation ofcopper from glass fiber by reducing peel resistance by95.4%at 500 K.It was revealed that the flexural fracturewas a transverse cracking caused by concentrated stresswhen the heating temperature was less than 500 K,andshifted to a vertical cracking after exceeding 500 K.展开更多
Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached rega...Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached regarding whether combined cable cerclage is required during intramedullary nailing treatment.This study is performed to compare the clinical effects of intramedullary nailing with cerclage and non-cerclage wiring in the treatment of irreducible spiral subtrochanteric fractures.Methods:Patients with subtrochanteric fractures admitted to our center from January 2013 to December 2021 were retrospectively analyzed.The patients were enrolled in the case-control study according to the inclusion and exclusion criteria and divided into the non-cerclage group and the cerclage group.The patients'clinical data,including the operative time,intraoperative blood loss,hospital stay,reoperation rate,fracture union time,and Harris hip score,were compared between these 2 groups.Categorical variables were compared using Chi-square or Fisher's exact test.Continuous variables with normal distribution were presented as mean±standard deviation and analyzed with Student's t-test.Nonnormally distributed variables were expressed as median(Q_(1),Q_(3))and assessed using the Mann-Whitney test.A p<0.05 was considered significant.Results:In total,69 patients were included in the study(35 patients in the non-cerclage group and 34 patients in the cerclage group).The baseline data of the 2 groups were comparable.There were no significant difference in the length of hospital stay(z=-0.391,p=0.696),operative time(z=-1.289,p=0.197),or intraoperative blood loss(z=-1.321,p=0.186).However,compared with non-cerclage group,the fracture union time was shorter(z=-5.587,p<0.001),the rate of nonunion was lower(χ^(2)=6.030,p=0.03),the anatomical reduction rate was higher(χ^(2)=5.449,p=0.03),and the Harris hip score was higher(z=-2.99,p=0.003)in the cerclage group,all with statistically significant differences.Conclusions:Intramedullary nailing combined with cable cerclage wiring is a safe and reliable technique for the treatment of irreducible subtrochanteric fractures.This technique can improve the reduction effect,increase the stability of fracture fixation,shorten the fracture union time,reduce the occurrence of nonunion,and contribute to the recovery of hip joint function.展开更多
In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires...In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.展开更多
Monofilament type of polyaromatic amide(PA)and carbon nanotube(CNT)composite fibers is presented.A concept of a lyotropic liquid crystal(LLC)constructed via a spontaneous self-assembly is introduced to mitigate the ex...Monofilament type of polyaromatic amide(PA)and carbon nanotube(CNT)composite fibers is presented.A concept of a lyotropic liquid crystal(LLC)constructed via a spontaneous self-assembly is introduced to mitigate the extremely low com-patibility between PA and CNT.These approaches provide an effective co-processing route of PA and CNT simultaneously to fabricate the uniform,continuous,and reliable composite fibers through a wet-spinning.Interestingly,the addition of a small amount PA into the dope solution of CNT governs the LLC mesophase not only in a spinneret stage but also in a coagulant region.Thus,the developed PA/CNT composite fibers have the high uniaxial orientational order and the close interfacial packing compared to the pure CNT fibers.The PA/CNT composite fibers achieve the outstanding tensile strength,electrical conductivity,and electrochemical response,while maintaining a lightweight.They also exhibit the chemical,mechanical,and thermal robustness.All of these advantages can make flexible,sewable,and washable PA/CNT composite fibers ideal nanocomposite materials for use in next-generation information and energy transporting system by replacing conventional metal electrical conductors.展开更多
Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJ...Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJTCs(heated junction thermocouples)are widely used for this purpose due to their ability to withstand extreme temperatures and radiation conditions.This article explores the role of HJTCs in reactor water level measurement and compares the performance of 2-wire and 3-wire connections.While the 2-wire connection is simple and cost-effective,it can introduce measurement inaccuracies due to wire resistance.In contrast,the 3-wire connection compensates for lead resistance,offering more precise and reliable measurements,particularly in long-distance applications.This paper discusses the operational considerations of these wiring configurations in the context of nuclear reactors and highlights the importance of choosing the appropriate connection type to optimize safety and measurement accuracy in PWR and BWR reactors.展开更多
BACKGROUND Accurate surgical fixation of intra-articular distal humerus fractures require olecranon osteotomy.Repair of osteotomy is achieved with a variety of techniques but no consensus has been achieved regarding t...BACKGROUND Accurate surgical fixation of intra-articular distal humerus fractures require olecranon osteotomy.Repair of osteotomy is achieved with a variety of techniques but no consensus has been achieved regarding the optimum technique for fixing the olecranon osteotomy.In this retrospective study,we compared the functional and radiological outcome of the two commonly used techniques of fixing olecranon osteotomy after fixing distal humerus intra-articular fractures.We hypothesized that olecranon osteotomy fixed with 6.5 mm cancellous intramedullary screw alone yielded better radiological and functional outcome than fixation with cerclage wire over cancellous screw applied in figure of eight as tension band wiring(TBW).AIM To determine the radiological and functional outcome of olecranon osteotomy fixation with cancellous screw alone vs cancellous screw combined with cerclage wiring applied as TBW.METHODS This retrospective study was conducted in Lady Reading Hospital Peshawar Pakistan.Intra-articular distal humerus fractures fulfilling the inclusion criteria and operated during 2023 to 2025 were included.Olecranon osteotomy fixation with 6.5 mm cancellous screw alone was labelled as group A while cerclage wire over cancellous screw in figure of eight as TBW were labelled as group B.The demographics,radiological and functional outcome in both groups were compared at one year using Mayo Elbow Performance Score and Quick Disabilities of the Arm,Shoulder,and Hand Score.RESULTS We included 32 patients in this study.The mean age of group A patients was 34±5.5 years while group B had a mean age of 34±6.2 years.Radiological union of olecranon osteotomy was achieved in all cases in both groups.Functional outcome however was significantly better in group A than in group B(P<0.05).The Mayo Elbow Performance Score was excellent in 14(87.5%)and good in 2(12.5%)patients in group A while 7(43.47%)patients had excellent outcome,5(31.25%)good and 4(25%)had fair outcome in group B.The mean Quick Disabilities of the Arm,Shoulder,and Hand Score was 24.5±2.1 and 78.1±12.1 in group A and B respectively(P<0.05).CONCLUSION Similar radiological union was achieved in all patients of olecranon osteotomy treated with intramedullary screw alone and intramedullary screw with TBW.Functional outcome however was significantly better in intramedullary screw alone than in intramedullary screw with TBW.展开更多
Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distri...Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.展开更多
The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully ci...The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),respectively.With the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire deposits.Microstructure characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α phases.The mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and discussed.The mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat treatment.No fracture occurred within the interfacial area,further suggesting the robust interface.The findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.展开更多
Amongst the many known techniques used for the management of fractures of the patella, the tension band wire fixation is a reliable treatment modality and has given consistently good results. In transverse patellar fr...Amongst the many known techniques used for the management of fractures of the patella, the tension band wire fixation is a reliable treatment modality and has given consistently good results. In transverse patellar fractures, a combination of cerclage wiring and tension band fixation gives a good mechanical stability and an environment conducive to healing. The fracture described herein is classified as 45-C1 (based on Orthopaedic Trauma Association classification) of the right knee of a forty three years old male patient. It was fixed with three vertical 1.5 mm K wires and double cerclage wire looped proximally through the quadriceps tendon and distally through the patellar ligament in a double figure-of-eight configuration. The average follow-up period was 7 months. The Activity of Daily Living Scale (ADLS) of the Knee Outcome Survey was used to assess symptoms and functional capability of the knee. The fracture union was achieved at an average of 10 weeks. Full range of knee motion was achieved by end of the third postoperative month. No complications, such as infection and implant failure were noted. The technique aims to stress the advantage of giving a balanced fixation addressing the bony elements (the fractured ends) as well as the soft tissue (the extensor apparatus).展开更多
基金Supported by National Key Technologies R&D Program of China(2015BAF23B03)National Nature Science Foundation of China(61672307)
文摘An automatic 3D wiring method for switchgear design is proposed in this paper. First, wiring constraints are created, and a corresponding evaluation model is proposed. Then, based on the structure of the cabinet, we propose a contour expansion scheme to construct rough paths. Different wiring features of the switchgear are used to connect rough local paths. All the paths are represented in a uniform data structure and forma path network. Finally, an improved A* algorithm is used to search the wiring path between the components in the routing network; the evaluation model is considered as heuristic rules for path searching. The result can satisfy the practical requirements of switchgear design. Experimental results are also provided.
文摘This paper introduces the necessity and superiority of auxiliary wiring WEBGIS, as well as system implementation difficulties and countermeasures. Then explained the general concept of auxiliary wiring systems, data interface response, and finally introduced the system wiring switchover function, and gave an example.
文摘Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.
基金Supported by Chinese national Science Foundation (61070124)the Fundamental Research Funds for the Central Universities (2012HGBZ0195)
文摘Identifying each process and their constraint relations from the complex wiring harness drawings quickly and accurately is the basis for formulating process routes. According to the knowledge of automotive wiring harness and the characteristics of wiring harness components, we established the model of wiring harness graph. Then we research the algorithm of identifying technology processes automatically, finally we describe the relationships between processes by introducing the constraint matrix, which is in or- der to lay a good foundation for harness process planning and production scheduling.
文摘MASEGO Dibetle, an information and communications technology （ICT） student at Tshwane University of Technology in South Africa, looks utterly delighted. Over the last two weeks, the 20-year-old has met with world leading experts in her field of study and visited state-of-the-art laboratories during her first trip to China.
文摘Purpose： Tension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires （K-wires） and a stainless steel wire loop placed in a vertically oriented figure-of-8. Methods： We used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners, lnterfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. Results： Placement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% （p 〈 0.05, Tukey post ]hoc test）. On cyclic loading, all the constructs with vertical figure-of-eight but none with a horizontal construct failed （p = 0.01; Fisher＇s exact test）. Permanent fracture displacement after cyclic loading was ,57% lower with horizontal figure- of-eight constructs （p 〈 0.05; t test）. Conclusion： Placing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
文摘This paper describes a built-in self-test (BIST) hardware overheadminimization technique used during a BIST synthesis process. The technique inserts a minimal amountof BIST resources into a digital system to make it fully testable. The BIST resource insertion isguided by the results of symbolic testability analysis. It takes into consideration both BISTregister cost and wiring overhead in order to obtain the minimal area designs. A Simulated Annealingalgorithm is used to solve the overhead minimization problem. Experiments show that consideringwiring area during BIST synthesis results in smaller final designs as compared to the cases when thewiring impact is ignored.
基金This study was funded by the project from the National Natural Science Foundation of China(Grant No.20777043/B070204)the National Science and Technology Support Program(2006BAC02A18).
文摘Mechanical waste-processing methods,whichcombine crushing and separation processes for therecovery of valuable materials,have been widely appliedin waste printed wiring board(PWB)treatment.However,both the high impact toughness and the tensile and flexuralstrengths of whole PWB with a laminated structure resultin great energy consumption and severe abrasion of thecutters during multi-level crushing.In addition,the hightemperatures occurring in continual crushing probablycause the decomposition of the polymer matrix.A thermalcrackmethod using residual steam as the heating mediumhas been developed to pre-treat waste PWBs.Thistreatment reduces the mechanical strength in order toimprove the recovery rate of valuable materials insubsequent mechanical recycling.The changes of thePWBs’macro-mechanical properties were studied toevaluate thermal expansion impacts associated withchanges in temperature,and the dynamic dislocationmicro-structures were observed to identify the fracturemechanism.The results showed that thermal cracking withsteam at the temperature of 500 K can effectively attenuatethe mechanical properties of waste PWBs,by reducing theimpact,tensile and flexural strengths respectively,by59.2%,49.3%and 51.4%,compared to untreated PWB.Thermal expansion can also facilitate the separation ofcopper from glass fiber by reducing peel resistance by95.4%at 500 K.It was revealed that the flexural fracturewas a transverse cracking caused by concentrated stresswhen the heating temperature was less than 500 K,andshifted to a vertical cracking after exceeding 500 K.
文摘Purpose:Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages.However,no definitive conclusion has been reached regarding whether combined cable cerclage is required during intramedullary nailing treatment.This study is performed to compare the clinical effects of intramedullary nailing with cerclage and non-cerclage wiring in the treatment of irreducible spiral subtrochanteric fractures.Methods:Patients with subtrochanteric fractures admitted to our center from January 2013 to December 2021 were retrospectively analyzed.The patients were enrolled in the case-control study according to the inclusion and exclusion criteria and divided into the non-cerclage group and the cerclage group.The patients'clinical data,including the operative time,intraoperative blood loss,hospital stay,reoperation rate,fracture union time,and Harris hip score,were compared between these 2 groups.Categorical variables were compared using Chi-square or Fisher's exact test.Continuous variables with normal distribution were presented as mean±standard deviation and analyzed with Student's t-test.Nonnormally distributed variables were expressed as median(Q_(1),Q_(3))and assessed using the Mann-Whitney test.A p<0.05 was considered significant.Results:In total,69 patients were included in the study(35 patients in the non-cerclage group and 34 patients in the cerclage group).The baseline data of the 2 groups were comparable.There were no significant difference in the length of hospital stay(z=-0.391,p=0.696),operative time(z=-1.289,p=0.197),or intraoperative blood loss(z=-1.321,p=0.186).However,compared with non-cerclage group,the fracture union time was shorter(z=-5.587,p<0.001),the rate of nonunion was lower(χ^(2)=6.030,p=0.03),the anatomical reduction rate was higher(χ^(2)=5.449,p=0.03),and the Harris hip score was higher(z=-2.99,p=0.003)in the cerclage group,all with statistically significant differences.Conclusions:Intramedullary nailing combined with cable cerclage wiring is a safe and reliable technique for the treatment of irreducible subtrochanteric fractures.This technique can improve the reduction effect,increase the stability of fracture fixation,shorten the fracture union time,reduce the occurrence of nonunion,and contribute to the recovery of hip joint function.
基金Funded by Hunan Provincial Natural Science Foundation(No.2023JJ40074)Hunan Provincial Education Department Excellent Youth Project(No.21B0757)Hunan Provincial Engineering Technology Center(No.2022TP2036)。
文摘In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.
基金supported by Korea Institute of Science and Technology(KIST)Open Research Program(ORP)and K-Lab Program,and grants from Mid-Career Researcher Program(2021R1A2C2009423)Korea Government MSIT(2021R1R1R1004226)Korea Research Institute for defense Technology planning and advancement(DAPA KRIT-CT-21-014).
文摘Monofilament type of polyaromatic amide(PA)and carbon nanotube(CNT)composite fibers is presented.A concept of a lyotropic liquid crystal(LLC)constructed via a spontaneous self-assembly is introduced to mitigate the extremely low com-patibility between PA and CNT.These approaches provide an effective co-processing route of PA and CNT simultaneously to fabricate the uniform,continuous,and reliable composite fibers through a wet-spinning.Interestingly,the addition of a small amount PA into the dope solution of CNT governs the LLC mesophase not only in a spinneret stage but also in a coagulant region.Thus,the developed PA/CNT composite fibers have the high uniaxial orientational order and the close interfacial packing compared to the pure CNT fibers.The PA/CNT composite fibers achieve the outstanding tensile strength,electrical conductivity,and electrochemical response,while maintaining a lightweight.They also exhibit the chemical,mechanical,and thermal robustness.All of these advantages can make flexible,sewable,and washable PA/CNT composite fibers ideal nanocomposite materials for use in next-generation information and energy transporting system by replacing conventional metal electrical conductors.
文摘Accurate water level measurement in nuclear reactors,particularly in PWRs(pressurized water reactors)and BWRs(boiling water reactors),is essential for ensuring the safety and efficiency of reactor operations.K-type HJTCs(heated junction thermocouples)are widely used for this purpose due to their ability to withstand extreme temperatures and radiation conditions.This article explores the role of HJTCs in reactor water level measurement and compares the performance of 2-wire and 3-wire connections.While the 2-wire connection is simple and cost-effective,it can introduce measurement inaccuracies due to wire resistance.In contrast,the 3-wire connection compensates for lead resistance,offering more precise and reliable measurements,particularly in long-distance applications.This paper discusses the operational considerations of these wiring configurations in the context of nuclear reactors and highlights the importance of choosing the appropriate connection type to optimize safety and measurement accuracy in PWR and BWR reactors.
文摘BACKGROUND Accurate surgical fixation of intra-articular distal humerus fractures require olecranon osteotomy.Repair of osteotomy is achieved with a variety of techniques but no consensus has been achieved regarding the optimum technique for fixing the olecranon osteotomy.In this retrospective study,we compared the functional and radiological outcome of the two commonly used techniques of fixing olecranon osteotomy after fixing distal humerus intra-articular fractures.We hypothesized that olecranon osteotomy fixed with 6.5 mm cancellous intramedullary screw alone yielded better radiological and functional outcome than fixation with cerclage wire over cancellous screw applied in figure of eight as tension band wiring(TBW).AIM To determine the radiological and functional outcome of olecranon osteotomy fixation with cancellous screw alone vs cancellous screw combined with cerclage wiring applied as TBW.METHODS This retrospective study was conducted in Lady Reading Hospital Peshawar Pakistan.Intra-articular distal humerus fractures fulfilling the inclusion criteria and operated during 2023 to 2025 were included.Olecranon osteotomy fixation with 6.5 mm cancellous screw alone was labelled as group A while cerclage wire over cancellous screw in figure of eight as TBW were labelled as group B.The demographics,radiological and functional outcome in both groups were compared at one year using Mayo Elbow Performance Score and Quick Disabilities of the Arm,Shoulder,and Hand Score.RESULTS We included 32 patients in this study.The mean age of group A patients was 34±5.5 years while group B had a mean age of 34±6.2 years.Radiological union of olecranon osteotomy was achieved in all cases in both groups.Functional outcome however was significantly better in group A than in group B(P<0.05).The Mayo Elbow Performance Score was excellent in 14(87.5%)and good in 2(12.5%)patients in group A while 7(43.47%)patients had excellent outcome,5(31.25%)good and 4(25%)had fair outcome in group B.The mean Quick Disabilities of the Arm,Shoulder,and Hand Score was 24.5±2.1 and 78.1±12.1 in group A and B respectively(P<0.05).CONCLUSION Similar radiological union was achieved in all patients of olecranon osteotomy treated with intramedullary screw alone and intramedullary screw with TBW.Functional outcome however was significantly better in intramedullary screw alone than in intramedullary screw with TBW.
基金funded by the National Natural Science Foundation of China(Grant No.42325503)the Hubei Provincial Natural Science Foundation and the Meteorological Innovation and Development Project of China(Grant Nos.2023AFD096 and 2022CFD122)+1 种基金the Natural Science Foundation of Wuhan(Grant No.2024020901030454)the Beijige Foundation of NJIAS(Grant No.BJG202304)。
文摘Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.
基金financially supported by the Agency for Science,Technology and Research(A*Star),Republic of Singapore,under the Aerospace Consortium Cycle 12“Characterization of the Effect of Wire and Powder Deposited Materials”(No.A1815a0078)。
文摘The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),respectively.With the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire deposits.Microstructure characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α phases.The mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and discussed.The mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat treatment.No fracture occurred within the interfacial area,further suggesting the robust interface.The findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.
文摘Amongst the many known techniques used for the management of fractures of the patella, the tension band wire fixation is a reliable treatment modality and has given consistently good results. In transverse patellar fractures, a combination of cerclage wiring and tension band fixation gives a good mechanical stability and an environment conducive to healing. The fracture described herein is classified as 45-C1 (based on Orthopaedic Trauma Association classification) of the right knee of a forty three years old male patient. It was fixed with three vertical 1.5 mm K wires and double cerclage wire looped proximally through the quadriceps tendon and distally through the patellar ligament in a double figure-of-eight configuration. The average follow-up period was 7 months. The Activity of Daily Living Scale (ADLS) of the Knee Outcome Survey was used to assess symptoms and functional capability of the knee. The fracture union was achieved at an average of 10 weeks. Full range of knee motion was achieved by end of the third postoperative month. No complications, such as infection and implant failure were noted. The technique aims to stress the advantage of giving a balanced fixation addressing the bony elements (the fractured ends) as well as the soft tissue (the extensor apparatus).
