repair operation
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2021 ◽  
Vol 50 (11) ◽  
pp. 3303-3311
Author(s):  
Nurul Syazana Mohamad Shah ◽  
Wan Azman Wan Sulaiman ◽  
Sarina Sulong ◽  
Ahmad Sukari Halim

Non-syndromic cleft lip and/or palate (NSCL/P) is a one of the most common birth defects occurs as a result of multi-factorial determinants such as genetic and environmental factors. Genetic factor has been studying widely across different population in identifying genes causing cleft defects. This study aims to validate the role of fibroblast growth factors (FGFs) and signalling molecules Wingless-type (Wnt) to the occurrence of cleft lip and/or palate among Malay population. Tissue skin was obtained from consented NSCL/P patients who underwent the cleft lip repair operation at the upper lip skin area and non NSCL/P individual was obtained from patient having traumatic injury at the lip area as a control. Expression pattern of FGF8, FGF10, Wnt8a, and LRP5/6 were tested and validated using Western Blot (WB) and quantitative Reverse Transcriptase-PCR (qRT-PCR). The fold change difference of FGF8 (0.614 ± 0.1012-fold), FGF10 (0.7188 ± 0.1017-fold) and Wnt8a protein (0.9051 ± 0.0142-fold) was downregulated by 1-fold in cleft lip (CL) tissues compared to the normal meanwhile LRP5/6 protein (1.2201 ± 0.1404-fold) was found upregulated by 1-fold. Validation testing confirmed that expression of FGF8 (p=0.014), Wnt8a (0.0762 ± 0.0227), LRP5 (0.3577 ± 0.1362) and LRP6 (0.3093 ± 0.2541) were significantly reduced in CL tissues compared to normal. This is the first study identified defective regulation of Wnt8a, LRP5, LRP6 and FGF8 in NSCL/P among Malays. These novel findings clearly explained the important role of growth factors FGF and Wnt signalling pathway in lip and palate formation during craniofacial development.



2021 ◽  
Vol 1 (4) ◽  
pp. 428-439
Author(s):  
Abada Zhour ◽  
Ghoudelbourk Sihem ◽  
DIB Djalel

The detection of faults in a wind turbine chain is of prime importance in order to maintain safety, enhance reliability and improve economic performance. In addition, wind systems have to ensure a continuity of service for a considerable period of time in the event of an electrical fault in the network or a fault in one of the elements of the electromechanical conversion system. This paper presents a fault detection methodology of the power converter within a wind turbine chain, equipped with a Doubly-Fed Induction Generator (DFIG). A configurable, fast, and accurate scheme is developed, the basis of which is the reliable identification of the failed switch. The solution proposed in this work involves the deployment of a redundant arm in the event of a fault; the replacement arm is utilized while waiting for a maintenance or repair operation to be carried out. The approach developed in this paper provides continuity of service after the occurrence of a fault in the network system and fault detection time is reduced. The validity of the proposed identification methodology is assessed by means of simulation of the model of a wind turbine conversion system.



Author(s):  
T. Tatarchuk ◽  
Yu. Kravchuk ◽  
V. Pelykh

Purpose. Analysis of methods of manufacturing centrifugal blades by 3D printing methods on the example of a modernized cooling system of the AI-450M engine of the Mi-2MSB helicopter. Research methods: calculation method of finite elements, analytical. Results. Studies have shown that the use of layer-by-layer printing technology of the centrifugal wheel of the cooling system provides the following opportunities and improvements: - reduce the percentage of rejection of finished products by 8–9 times; - reduce material consumption by 300–400 %; - increase the speed of production, experiments and testing the manufacture of working elements through the development of new technologies for rapid production (rapid fabrication); - easy printing of previously “impossible” geometry. The analysis of possible types of manufacturing of  working centrifugal wheel and the calculated estimation of thermodynamic parameters in the course of step-by-step drawing of layers of metal is carried out. The problem of a large percentage of defects in the process of classical-mechanical milling of blades was solved by changing the type of production to additive one. Scientific novelty. In today's world, the spread of CAD / CAM / CAE / PLM technologies and the accumulation of a wide library of materials open up a large number of new and more efficient, in terms of economy and quality, methods of manufacturing components and units. Following the example of such giants in the production of aircraft engines as Rolls-Royce Motor, General Electric and Pratt & Whitney, it is clear that the use and development of the latest methods of three-dimensional printing is appropriate. Practical value. The obtained results are important in the further process of production and modernization ofMi-2 helicopter of all modifications with the latest engines, as well as for projects for the development of helicopter construction in Ukraine - МСБ-2 “Hope”, МСБ -6 “Otaman”, МСБ-8 and others. The ability to increase the efficiency of manufacturing the main working elements - blades allows you to reduce the cost of components, their further repair, operation. The most important factor is to increase reliability, as in the manufacture reduces the likelihood of defects, which will not be detected at the stages of intermediate and final control.



2021 ◽  
Author(s):  
Melvin Ramcharitar

Approximately thirty to forty percent of all bridges across North America have some form of deterioration on them. Many organizations/agencies across North America are investing significant amounts of money on repairing and rehabilitating their bridges. The reason being, these bridges are deteriorating due to heavy use (overloading from today's oversized trucks), old age (many built in late 1950s and 1960s) and environmental and chemical attacks (deicing salt applications during the winter season). The purpose of this thesis concentrated on one area, namely bridge decks. To better understand how these organizations/agencies were dealing with bridge deck deterioration, a survey containing thirteen questions was developed and sent out throughout North America, to Department of Transportation, Ministry of Transportation, Municipalities, Bridge Authorities and Consultants. The survey was made up of six parts, each focusing on different areas during a bridge rehabilitation/repair operation. Areas looked at were: Condition Surveys, Concrete Removal, Rehabilitation Techniques, Environmental Impacts and Service Life.



2021 ◽  
Author(s):  
Melvin Ramcharitar

Approximately thirty to forty percent of all bridges across North America have some form of deterioration on them. Many organizations/agencies across North America are investing significant amounts of money on repairing and rehabilitating their bridges. The reason being, these bridges are deteriorating due to heavy use (overloading from today's oversized trucks), old age (many built in late 1950s and 1960s) and environmental and chemical attacks (deicing salt applications during the winter season). The purpose of this thesis concentrated on one area, namely bridge decks. To better understand how these organizations/agencies were dealing with bridge deck deterioration, a survey containing thirteen questions was developed and sent out throughout North America, to Department of Transportation, Ministry of Transportation, Municipalities, Bridge Authorities and Consultants. The survey was made up of six parts, each focusing on different areas during a bridge rehabilitation/repair operation. Areas looked at were: Condition Surveys, Concrete Removal, Rehabilitation Techniques, Environmental Impacts and Service Life.



Author(s):  
Zhan Gao ◽  
Jin Yu ◽  
Zewei Zhang ◽  
Jianhua Li ◽  
Jiangen Yu

Aims:This study aimed to investigate the safety, feasibility and availability of perimembranous ventricular septal defect (PmVSD) closure via a left parasternal ultra-minimal trans intercostal incision in children. Methods and results:From January 2015 to January 2019, 131 children with restrictive PmVSDs were enrolled in this study and successfully done in 126 patients (96.18%). PmVSDs were occluded via an ultra-minimal trans intercostal incision (≤1 cm), and the entire occlusive process was guided and monitored by TEE. A pericardium hanging technique was employed without sternal incision. PmVSDs were closed through a short delivery sheath assembled using a concentric occluder device. All patients were followed up for a perid ranging from18 months to 24 months. Thirteen patients with PmVSD had aneurysm of membranous septum (AMS). Multistream (more than or equal to 2) PmVSDs with AMS were found in eleven cases. After the operation, mild residual shunt beside the amplatzer occluder in one patient was found and had self-healing result during the 5-month follow-up period. Five patients transferred to ventricular septal defect repair operation under direct visualization with a cardiopulmonary bypass. One reason was ventricular fibrillation when guide wire passed the PmVSD, another was device dislocation, and others were the guide wire cannot pass through the PmVSD. Conclusions:PmVSDs closure using a concentric occluder via a left parasternal ultra-minimal trans intercostal incision under TEE guidance is feasible, safe, and effective in children. This approach can be considered as an alternative treatment to open-heart surgery for restrictive PmVSDs.



2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xin Niu

In the lossy wireless network routing system based on RPL technology, an improved DODAG construction optimization scheme is proposed for sensor nodes with low-power dissipation in the interference environment. If a node discovers that all paths between it and its neighbors have failed, the node reset action begins. Once the node reset is complete, the DODAG system build process is resumed. This prevents the DODAG root from initiating a global fix by incrementing the DODAG VersionNumer to produce a new version of the DODAG in a disruptive environment. The power loss caused by this global repair operation is avoided. The performance of DODAG in interference environment is enhanced, and the data retransmission rate is reduced.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luc Joyeux ◽  
Allan Javaux ◽  
Mary P. Eastwood ◽  
Felix R. De Bie ◽  
Gert Van den Bergh ◽  
...  

AbstractOpen fetal surgery for spina bifida (SB) is safe and effective yet invasive. The growing interest in fetoscopic SB repair (fSB-repair) prompts the need for appropriate training. We aimed to develop and validate a high-fidelity training model for fSB-repair. fSB-repair was simulated in the abdominal cavity and on the stomach of adult rabbits. Laparoscopic fetal surgeons served either as novices (n = 2) or experts (n = 3) based on their experience. Technical performance was evaluated using competency Cumulative Sum (CUSUM) analysis and the group splitting method. Main outcome measure for CUSUM competency was a composite binary outcome for surgical success, i.e. watertight repair, operation time ≤ 180 min and Objective-Structured-Assessment-of-Technical-Skills (OSATS) score ≥ 18/25. Construct validity was first confirmed since competency levels of novices and experts during their six first cases using both methods were significantly different. Criterion validity was also established as 33 consecutive procedures were needed for novices to reach competency using learning curve CUSUM, which is a number comparable to that of clinical fSB-repair. Finally, we surveyed expert fetal surgeons worldwide to assess face and content validity. Respondents (26/49; 53%) confirmed it with ≥ 71% of scores for overall realism ≥ 4/7 and usefulness ≥ 3/5. We propose to use our high-fidelity model to determine and shorten the learning curve of laparoscopic fetal surgeons and retain operative skills.



2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mehrdad Rostami ◽  
Kamal Berahmand ◽  
Saman Forouzandeh

AbstractThe feature selection is an essential data preprocessing stage in data mining. The core principle of feature selection seems to be to pick a subset of possible features by excluding features with almost no predictive information as well as highly associated redundant features. In the past several years, a variety of meta-heuristic methods were introduced to eliminate redundant and irrelevant features as much as possible from high-dimensional datasets. Among the main disadvantages of present meta-heuristic based approaches is that they are often neglecting the correlation between a set of selected features. In this article, for the purpose of feature selection, the authors propose a genetic algorithm based on community detection, which functions in three steps. The feature similarities are calculated in the first step. The features are classified by community detection algorithms into clusters throughout the second step. In the third step, features are picked by a genetic algorithm with a new community-based repair operation. Nine benchmark classification problems were analyzed in terms of the performance of the presented approach. Also, the authors have compared the efficiency of the proposed approach with the findings from four available algorithms for feature selection. Comparing the performance of the proposed method with three new feature selection methods based on PSO, ACO, and ABC algorithms on three classifiers showed that the accuracy of the proposed method is on average 0.52% higher than the PSO, 1.20% higher than ACO, and 1.57 higher than the ABC algorithm.



2021 ◽  
Vol 37 ◽  
pp. 00103
Author(s):  
Valery Zhdanov ◽  
Elena Logacheva ◽  
Viktor Yarosh ◽  
Alexander Ivashina

Application of mathematical methods of cost optimization for repair and maintenance of electrical equipment of agro-industrial enterprises is one of the important and promising directions for increasing the efficiency of electrical equipment operation management in agriculture. Mathematical programming systems use graphical and related attributive information in solving optimization problems. As graphical information in these systems we used maps, plans, diagrams, schedules of preventive measures from which the list of equipment for certain types of repair and maintenance, their labor intensity for individual objects, types of equipment and in total for the enterprise are established. Databases of electrical equipment are used as attributive information to describe electrical equipment of agro-industrial enterprises. Due to joint processing of graphical and attributive information in optimization systems, all stages of work with spatial data are more operative. Beginning from spatial data search, selection and analysis we can make a specific decision during the operation control of electrical equipment. This article considers maintenance and repair operation (MR) as a task of mathematical programming with cost optimization and deals with three approaches to the organization of this task. The expediency of using each method of solution is analyzed. The structural schemes, equations describing mathematical models, advantages and disadvantages of the presented models are given. We marked prospect of using linear programming programs for the decision of the given optimization problem by means of the inverse matrix method, i.e. the modified simplex method and computing algorithm with a standard sequence of operations.



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