Tension Wire Research Articles

Разработка программно-аппаратного комплекса поддержки принятия решений по режимам эксплуатации контактной сети с помощью машинного обучения

Рассмотрены особенности работы и функциональная схема программно-аппаратного комплекса поддержки принятия решений по режимам эксплуатации контактной сети с применением технологии машинного обучения. Предлагаемый комплекс осуществляет сбор, накопление и обработку информации о техническом состоянии объектов наблюдения, а также дает рекомендации оперативно-техническому персоналу для принятия продуктивных решений (снижение скорости движения на участке, усиление готовности обслуживающего персонала и т.д.). Работа комплекса представлена на примере определения натяжения проводов контактной сети с помощью диагностических сенсоров и модели дерева решений для классификации цифровых отпечатков. Обучение математической модели классификации проведено в MATLAB Classification Learner на массиве виброускорений проводов контактной сети, смоделированном конечно-элементной моделью при различных вариантах натяжения. Предлагаемый программный комплекс может быть интегрирован в аналогичные системы диагностики и контроля работы электрооборудования с целью поддержки принятия решений персоналом сферы электроэнергетики.

OPEN SURGERY FOR PATELLAR TENDON RUPTURE AND TIBIAL TUBEROSITY AVULSION FRACTURE IN PRE-EXISTING OSGOOD SCHLATTER LESION: A CASE REPORT

Background: In Osgood Schlatter Disease, despite being a self-limiting disease during adolescence, various complications of Osgood Schlatter Disease could also present in adulthood. An uncommon injury pattern requires surgical treatment. This study aims to understand the implementation of surgery in managing complications case of Osgood Schlatter Disease.Case Report: We present a rare case of complete patellar tendon rupture and tibial tuberosity avulsion fracture following a low-energy motor vehicle accident landing on his left knee in a 42 years old active male, who later discovered is having a pre-existing Osgood Schlatter Disease. This patient is treated with an open surgery fixating the tibial tuberosity using a single lag screw and eight tension wires, followed by primary repair of the patellar tendon, including its retinaculum.Discussion: Weakened structure from pre-existing Osgood Schlatter lesion may cause uncommon and profound injury pattern that requires surgical treatment. Conservative treatment no longer has a place in this case. The various surgical treatment methods have been reported; however, surgical modification technique is performed accordingly due to the complicated case presentation.Conclusion: Surgical treatment is the most suitable treatment option in managing this uncommon injury pattern complication of Osgood Schlatter Disease.

Effect of Pantograph’s Main Structure on the Contact Quality in High-Speed Railway

In general, the electrical energy is provided to the high-speed train through the pantograph-catenary sliding contact. The variation of the dynamic contact force is expected to be small enough to keep the good current collection quality and to extend the service life of the pantograph-catenary system. In this paper, the two tension wires of the catenary are discretized by the sine-series expansions, a multibody dynamics theory based on relative coordinates is adopted to describe the dynamic behavior of the pantograph, and the standard deviation (STD) of dynamic contact force is used as the indicator to evaluate the contact quality. The objective is to investigate how the variations of the pantograph’s main structure influence the contact quality, which may support the structural design and parameter optimization of the pantograph in high-speed railway.

Design Procedure and Ultimate Capacity of New Turnbuckle for Measuring Tensile Force

A turnbuckle is a device that is installed between tension wires or rods for the purpose of adjusting the tensile force and length of tension members. Tensile force can be adjusted by rotating the body of turnbuckle but the conventional turnbuckle is incapable of measuring tensile force without specific measurement equipment such as a load cell, accelerometer and data logger, etc. New turnbuckles have therefore been developed for adjustment and easy measurement of tensile force. In previous works, the newly developed turnbuckles have been tested and analyzed in order to establish their size, shape and measurable load capacity. The present study addresses the design process and ultimate capacities of new turnbuckles having measurable load capacities of 100, 200 and 300 kN. The ultimate load capacities are obtained via experimental investigation. For each turnbuckle the ultimate loads and the first yield loads are about 5 times and 1.5 times the service load, respectively.

FEMORAL LENGTHENING USING MODIFIED LOW PROFILE ILIZAROV FIXATOR IN ADOLESCENTS: DESCRIPTION OF THE TECHNIQUE AND EARLY EXPERIENCE

We modified the original Ilizarov frame described for femoral lengthening and used two full rings fixed by 3 tensioned wires for each with an osteotomy in the distal metaphyseal area. Four femoral lengthenings were performed and followed up for at least 30 months. Average age of our patients was 15 years and length gain was 74±18mm with one patient had concomitant correction of valgus deformity. The planned lengthening was achieved in all patients with healing index 19±2 days/cm. Advantages for this low profile frame are mainly less bulky external fixator and fewer transosseous elements and therefore pin site problems.

Reconstruction of infected nonunion of the distal humerus by Ilizarov external fixator.

Infected nonunion of the distal humerus represents a true challenge as the fragment is usually small and difficult for fixation. The aim of the present study is to assess the results of Ilizarov external fixator in management of infected nonunion of the distal third humerus. Twenty-three patients with infected nonunion of the distal humerus were included in this study. The ages ranged from 19 to 58 years with an average of 35 years. Seventeen cases were males and 6 were females. All patients were treated by radical debridement and application of Ilizarov external fixator in one stage surgery. Bony union was achieved in all cases. Bone graft was required in 12 patients with hypotrophic nonunion. The external fixation time ranged from 4 to 9 months with an average of 5.6 months. Infection was controlled in all cases without recurrence during the period of follow up. The complications included pin tract infection in 7 cases, radial nerve injury in one case, elbow stiffness in 4 cases and refracture after frame removal in one case. Ilizarov external fixator is effective in management of infected nonunion of the distal humerus. The thin tensioned wires produce good grip in the small or osteoporotic bone fragments.

Effect of cutting parameters on surface integrity of monocrystalline silicon sawn with an endless diamond wire saw

The cutting of silicon wafers using multi-diamond wire sawing is a critical stage in solar cell manufacturing due to brittleness of silicon. Improving the cutting process output requires an in-depth understanding of phenomena associated with cutting parameters. In order to investigate the influence of diamond wire sawing on surface integrity of monocrystalline silicon, a looped diamond wire was used and cutting parameters wire cutting speed, feed rate and wire tension were varied. The surface morphology was observed by scanning electron microscopy. Surface roughness Sa was measured with a non-contact profilometer. The brittle-ductile transition was identified by presence of residual phases on sawn surface. A bevel-polishing method was employed to determine the microcrack depth. The results show that with higher feed rate the surface presents deeper and wider craters because of deeper penetration of diamond grain. On increasing wire cutting speed, there were more regions formed in ductile mode. The higher Sa values was observed on increasing both feed rate and wire tension, while Sa decreased with an increase in wire cutting speed. The brittle mode was predominant with an increase in feed rate, resulting in Si-I phase in regions formed in fragile mode. Material removal in ductile mode led to appearance of a-Si phase at high wire cutting speed. No significant effect was observed on increasing wire tension. Subsurface microcracks mainly initiating from bottom of grooves generated by cutting mechanism. The most appropriate set of cutting parameters is the lowest feed rate and wire tension and highest wire cutting speed.

Prediction intervals for load‐sharing systems in accelerated life testing

AbstractBased on accelerated lifetime experiments, we consider the problem of constructing prediction intervals for the time point at which a given number of components of a load‐sharing system fails. Our research is motivated by lab experiments with prestressed concrete beams where the tension wires fail successively. Due to an audible noise when breaking, the time points of failure could be determined exactly by acoustic measurements. Under the assumption of equal load sharing between the tension wires, we present a model for the failure times based on a birth process. We provide a model check based on a Q‐Q plot including a simulated simultaneous confidence band and four simulation‐free prediction methods. Three of the prediction methods are given by confidence sets where two of them are based on classical tests and the third is based on a new outlier‐robust test using sign depth. The fourth method uses the implicit function theorem and the δ‐method to get prediction intervals without confidence sets for the unknown parameter. We compare these methods by a leave‐one‐out analysis of the data on prestressed concrete beams. Moreover, a simulation study is performed to discuss advantages and drawbacks of the individual methods.

Death due to Accidental Electrocution: Social Aspects: A Case Report

Background: The passage of electric current through human body can produce multiple effects, commonly known as Electrocution. The passage of electric current through the body produces wide range of effects, varying from insignificant localized spasm, little or no contact burns, fatality with little or no burns or extreme severe burning. Case Report: A detailed history of the incident revealed that the bike rider skid and fell on the water logged road in rainy season and came in contact with the high tension wire and was electrocuted. The second person tried to attend to the bike driver and he also came in contact with the same wire and died instantly. Autopsy revealed external electrocution injuries on both deceased. Both these deaths were accidental in nature and were preventable. Histopathological examination of the electric contact point showed elongation and streaming of nuclei with focal inter-epidermal and epidermal-dermal separation. Conclusion: This present article focuses on need for proper development of water drainage system especially during rainy season and also to generate public awareness regarding regular supervision of roadside Electric pole and wires which could prevent similar accidents. A detailed history regarding the incidence, scene visit, circumstantial evidence, statement of witness and proper postmortem examination with the histopathological examination are recommended prior to concluding the cause of death in case of alleged death due to electrocution. The data can be used for further planning and implementation of adequate measures to prevent accidents and thereby benefit the society.

Failure cause of bridge tie-down cables after 30 years of service

The paper approaches the sensitivity to stress corrosion cracking of zinc-coated, high-strength, eutectoid steel wires extracted from collapsed prestressing strands after 30 years of service as tie-down cables of a cable-stayed bridge. The observed damage of wires consisting of pitting corrosion, cross-section losses and even failure, varied in intensity from one cable to another and allowed the assessment of the effect of damage level on the mechanical behavior of wires, as well as that of the susceptibility of the galvanized wires to aggressive environments. The results were obtained by performing fracture tests of service-damaged wires under constant load and under increasing load at low strain rate, while exposed to an aggressive media (ammonium thiocyanate - FIP solution). The SEM analysis of the fracture and lateral surfaces of the tested wires proved the similitude between the service and laboratory-induced damage. It also provided evidence of hydrogen embrittlement in the failure mechanism of the wires. Accordingly, the service ruptures were attributed to progressive cracking by environmentally assisted, hydrogen embrittlement propitiated by the partial dissolution and cracking of the zinc coating in the tensioned wires.

Electromagnetic Field and Changing the Ambient Temperature of High Tension Wires

Electromagnetic Field and Changing the Ambient Temperature of High Tension Wires

Incorporation and validation of clinically relevant performance metrics of simulation (CRPMS) into a novel full-immersion simulation platform for nerve-sparing robot-assisted radical prostatectomy (NS-RARP) utilizing three-dimensional printing and hydrogel casting technology.

To incorporate and validate clinically relevant performance metrics of simulation (CRPMS) into a hydrogel model for nerve-sparing robot-assisted radical prostatectomy (NS-RARP). Anatomically accurate models of the human pelvis, bladder, prostate, urethra, neurovascular bundle (NVB) and relevant adjacent structures were created from patient MRI by injecting polyvinyl alcohol (PVA) hydrogels into three-dimensionally printed injection molds. The following steps of NS-RARP were simulated: bladder neck dissection; seminal vesicle mobilization; NVB dissection; and urethrovesical anastomosis (UVA). Five experts (caseload >500) and nine novices (caseload <50) completed the simulation. Force applied to the NVB during the dissection was quantified by a novel tension wire sensor system fabricated into the NVB. Post-simulation margin status (assessed by induction of chemiluminescent reaction with fluorescent dye mixed into the prostate PVA) and UVA weathertightness (via a standard 180-mL leak test) were also assessed. Objective scoring, using Global Evaluative Assessment of Robotic Skills (GEARS) and Robotic Anastomosis Competency Evaluation (RACE), was performed by two blinded surgeons. GEARS scores were correlated with forces applied to the NVB, and RACE scores were correlated with UVA leak rates. The expert group achieved faster task-specific times for nerve-sparing (P = 0.007) and superior surgical margin results (P = 0.011). Nerve forces applied were significantly lower for the expert group with regard to maximum force (P = 0.011), average force (P = 0.011), peak frequency (P = 0.027) and total energy (P = 0.003). Higher force sensitivity (subcategory of GEARS score) and total GEARS score correlated with lower nerve forces (total energy in Joules) applied to NVB during the simulation with a correlation coefficient (r value) of -0.66 (P = 0.019) and -0.87 (P = 0.000), respectively. Both total and force sensitivity GEARS scores were significantly higher in the expert group compared to the novice group (P = 0.003). UVA leak rate highly correlated with total RACE score r value = -0.86 (P = 0.000). Mean RACE scores were also significantly different between novices and experts (P = 0.003). We present a realistic, feedback-driven, full-immersion simulation platform for the development and evaluation of surgical skills pertinent to NS-RARP. The correlation of validated objective metrics (GEARS and RACE) with our CRPMS suggests their application as a novel method for real-time assessment and feedback during robotic surgery training. Further work is required to assess the ability to predict live surgical outcomes.

Surface Deformation Monitoring for a Concrete-face Rockfill Dam

Deformation monitoring is very important in the management of water dams. For rockfill dams, the surface deformation in run-time stage can be tiny and the true values can be easily covered by measuring errors when using traditional methods. In this paper, the Tension Wire Alignment System and the Hydro-static Leveling System are employed to measure the surface deformation of Zeya dam. The collected data indicates the good performance of the systems. The deformation patterns are then analyzed based on the monitoring data.

THE DEVELOPMENT OF A TECHNIQUE OF DYNAMIC TESTS OF SUPPORTS

Known methods of testing supports create longitudinal and transverse static load applied to the support. In real conditions the majority of the damage of the supports is connected with the influence on them of dynamic loads, which can exceed the static. The proposed method allows to conduct experimental studies of cascade processes of destruction of anchor site due to a wire breakage, when the potential energy of the tension wires is converted into a dynamic influence on the design of supports.

Application of Pre-stranded Tensile Clamp for Aluminum Composite Carbon Fiber Core

The growth of electricity demand has put forward higher requirements for transmission line performance. Aluminum composite carbon fiber cores (ACCC) has better performance than traditional steel core aluminum conductor and can better meet the requirements of power transmission and transformation field. However, at present, the wedge-shaped self-locking tension clamp is usually used for aluminum composite carbon fiber cores, which is complicated in construction technology and poor in economy, which restricts the promotion and application of aluminum composite carbon fiber cores.In order to solve the above problems, three kinds of tension clamp structures applied to different specifications of aluminum conductors composite core are optimized. Through the strength and grip test of the clamp, it is verified that the grip force of the clamp structure designed can reach 95% of the rated tensile strength of the conductor. Finally, through the comparative analysis of construction and installation, it is concluded that the pre-twisted tension wire clamp designed has a good economic effect.

Dynamic Behavior of Floating Tidal Current Power Device Considering Turbine Specifications

Tidal current power is one of the energy sources of the ocean. Electricity can be generated by converting the flow energy of the current into the rotational energy of a turbine. Unlike tidal barrage, tidal current power does not require dams, which have a severe environmental impact. A floating-type tidal current power device can reduce the expensive support and installation cost, which usually account for approximately 41% of the total cost. It can also be deployed in relatively deep water using tensioned wires. The dynamic behavior of a floater and turbine force are coupled because the thrust and moment of the turbine affect the floater excursion, and the motion of the floater can affect the incoming speed of the flow into the turbine. To maximize the power generation and stabilize the system, the coupled motion of the floater and turbine must be extensively analyzed. However, unlike pile-fixed devices, there have been few studies involving the motion analysis of a moored-type tidal current power device.In this study, the commercial program OrcaFlex 10.1a was used for a time domain motion analysis. In addition, in-house code was used for an iterative calculation to solve the coupled problems. As a result, it was found that the maximum mooring load of 200 kN and the floater excursion of 5.5 m were increased by the turbine effect. The load that occurred on the mooring system satisfied the safety factor of 1.67 suggested by API. The optimum mooring system for the floating tidal current power device was suggested to maximize the power generation and stability of the floater.

Joint-preserving treatment for type 3 sequelae following fracture of the proximal humerus with small head fragments

BackgroundAlthough nonunions of the proximal humerus are rare, they cause significant disability to patients. Surgical reconstruction is challenging, especially with small and excavated head fragments. A promising surgical option is open reduction and stabilization using the Humerusblock device along with tension wires. The aim of this retrospective investigation was to evaluate the clinical and radiological results of this procedure. Materials and methodsFifteen patients with symptomatic surgical neck nonunions were treated with open reduction and internal fixation using the Humerusblock device without bone grafting. All patients showed a loss of bone stock, leading to excavated head fragments. The mean interval from injury to the described treatment was 6.2 months (range, 3.4–10.7). At a mean follow-up of 40.5 months, the Constant-Murley score was documented, pain and patient satisfaction were evaluated using a visual analogue scale, and x-rays were taken in two planes. ResultsThe patients’ mean age was 69.7 years (range, 52–83). The mean Constant-Murley score improved from 24 points before surgery to 62 points at follow-up, which was an average of 80.8% of the score obtained for the contralateral arm. Radiological examination confirmed bony healing in 14 patients. All but one patient felt satisfied with the results. Three patients required revision surgery because of a hematoma, and early metal removal was performed in one patient because of infection. ConclusionNonunions of humeral surgical neck fractures can be successfully treated by fixation using the Humerusblock device along with tension wires without the need for additional bone grafting. Especially in patients with flat, concave head fragments, this procedure remains a promising reconstructive option to arthroplasty. Level of EvidenceLevel IV; Therapeutic retrospective case series.

Development of the method of dynamic tests support of air transmission lines

Known methods of testing supports create longitudinal and transverse static load applied to the support. In real conditions the majority of the damage of the supports is connected with the influence on them of dynamic loads, which can exceed the static. The proposed method allows to conduct experimental studies of cascade processes of destruction of anchor site due to a wire breakage, when the potential energy of the tension wires is converted into a dynamic influence on the design of supports.

Bilateral Proximal Humerus Fracture - a Rare Combination with a High Complication Rate after Surgery.

Bilateral acute proximal humerus fractures are rare. There are no data available about these bilateral injuries. The aim of the study was to analyse bilateral proximal humerus fractures retrospectively in terms of incidence, complications and revisions. All bilateral proximal humerus fractures were evaluated retrospectively using the institution's database, with the focus on cause of the injury, fracture severity and the clinical course compared to published information on monolateral proximal humerus fractures. Bilateral posterior dislocation fractures were excluded, because these fractures are a separate entity. Between 2005 and 2016, n = 17 patients were primarily treated within our hospital for an acute proximal humerus fracture on both sides (n = 12 female, n = 5 male, average age: 68 years; overall 34 proximal humerus fractures). The general trauma mechanism was a fall on both arms (82% [18% polytrauma]). There were 65% displaced 3-/4-part proximal humerus fractures. Angle-stable plate osteosynthesis was performed predominantly (64%), followed by fracture prosthesis (18%; tension wiring: 3%; non-operatively: 15%). Overall, n = 10 patients (59%) or n = 18 (53%) proximal humerus fractures developed a complication, primarily with loss of reduction or implant loosening (44%). In n = 14 (78%) of the complications further operations were necessary. Alcohol abuse was increasingly found in 29% of the cases within the bilateral patient cohort compared to patients with monolateral fractures. Bilateral proximal humerus fractures are mainly associated with comminuted displaced fractures and a higher complication rate in comparison to monolateral fractures after surgical treatment.

Isolated Medial Malleolus Fractures: Conventional Techniques Versus Headless Compression Screw Fixation

The aim of the present study was to evaluate the clinical and radiologic results of surgically treated isolated medial malleolar fractures and compare the clinical and radiologic results of the fixation methods of headless cannulated fully threaded compression screws and cancellous lag screws and tension band wiring. We included 32 patients who attended the final follow-up examination. Group 1 consisted of 11 patients (34.4%) treated with headless cannulated fully threaded compression screws. Group 2 consisted of 10 patients (31.2%) treated with cancellous lag screws. Group 3 consisted of 11 patients (34.4%) treated with Kirschner wires and intraosseous tension wiring. Standard ankle radiographs, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, and visual analog scale for pain were assessed. No statistically significant differences were found among the groups in regard to age, gender, preoperative fracture type, follow-up time, radiologic bone union time, and baseline AOFAS scale scores. The interval to fracture healing was 2.2 ± 0.42 months in group 1, 2.5 ± 0.71 months in group 2, and 2.45 ± 0.52 months in group 3. The AOFAS ankle-hindfoot scale score was 96.73 ± 5.55 in group 1, 93.1 ± 5.43 in group 2, and 93.73 ± 5.52 in group 3. Hardware removal was not required in any patient in group 1 but was required in 2 patients (20%) in group 2 and 3 patients (27.3%) in group 3. The visual analog scale score for pain on palpation at the medial malleolus was significantly lower statistically in the headless compression screw group (group 1; p = .003).