Artigos de revistas: "Stepped repair"

1

Li, Hui, Cheng Chen, Tongguang Wang e Long Wang. "Experimental Study of Stepped-Lap Scarf Joint Repair for Spar Cap Damage of Wind Turbine Blade in Service". Applied Sciences 10, n.º 3 (31 de janeiro de 2020): 922. http://dx.doi.org/10.3390/app10030922.

Texto completo da fonte

Resumo:

The objective of this paper was to design configuration parameters for a stepped-lap scarf joint repair, which can be used for spar cap damage of a wind turbine blade in service and to realize the post-repair monitoring. Two experimental studies were included. First, tensile test for the unidirectional tape specimens with a large aspect ratio repaired using a multiple stepped-lap scarf joint method was carried out. The results showed that the reinforcement layer could effectively improve the load-carrying capacity of the repaired zone. The stepped-lap joint surface was identified as the weak part of the spar cap repair, which should be monitored. Second, by embedding carbon nanotube buckypaper sensors on the stepped-lap joint surface of the repaired specimens, quasi-static tensile tests and fatigue tests were carried out. According to the resistance response of the sensors, the quasi-static tensile test confirmed the failure processes, namely the stiffness turning point, damage evolution, crack propagation, and fracture. The fatigue test could accurately identify the progressive failure, namely the initial damage, damage accumulation, initial cracking, and crack propagation to structural failure. The above tests provided an important configuration parameter basis for evaluating the spar cap repair scheme and presented a promising method for the health monitoring of a spar cap after repair.

Estilos ABNT, Harvard, Vancouver, APA, etc.

2

Psarras, Spyridon, Theodoros Loutas, Magdalini Papanaoum, Orestis Konstantinos Triantopoulos e Vasilis Kostopoulos. "Investigating the Effect of Stepped Scarf Repair Ratio in Repaired CFRP Laminates under Compressive Loading". Journal of Composites Science 4, n.º 4 (19 de outubro de 2020): 153. http://dx.doi.org/10.3390/jcs4040153.

Texto completo da fonte

Resumo:

In this work the effectiveness of stepped repairs to damaged fiber reinforced composite materials is investigated by using previously validated numerical models which were compared with tested repaired composite plates. Parametric studies were carried out in order to assess the scarf ratio (i.e., step length to ply thickness ratio) influence on ultimate forces, displacements, stresses and stiffnesses. FE models with repair scarf ratios varying from the value of 20 to the value 60 with a step increase of 10 were developed. The numerical models allowed a direct comparison of the influence that the scarf ratio had to the strength and stiffness restoration of the repaired composite structure. The study verifies that the restoration of the strength of a damaged laminate depends largely on the size of the repair patch. Generally, the bigger the size of a patch, the stronger the repaired structure is, up to a critical threshold size. To maximize the strength restoration, it is advised that the number of steps in each patch are no less than the number of plies on the base laminate.

Estilos ABNT, Harvard, Vancouver, APA, etc.

3

Collombet, Francis, Yves Davila, Sergio Avila, Alexander Morales, Laurent Crouzeix, Yves-Henri Grunevald, Hilario Hernandez, Nathalie Rocher e François Cénac. "Proof of a composite repair concept for aeronautical structures: a simplified method". Mechanics & Industry 20, n.º 8 (2019): 812. http://dx.doi.org/10.1051/meca/2020056.

Texto completo da fonte

Resumo:

This paper provides an illustration of all stages of primary aeronautical composite structure repair by using industrial tools and scientific methodologies, as well as numerical tools to simplify the cross-over analysis of the mechanical behaviour of the repaired area. Economically and scientifically speaking, one of the main challenges of composite repair (for monolithic long fiber composite parts) consists of promoting a bonded composite patch option without additional riveted doublers. To address this challenge, size reduction of the patch could be mandatory. A patent (jointly owned by ICA, Bayab Industries and CES), entitled “Method for repairing a wall consisting of a plurality of layers”, is devoted to reducing repair patch dimensions of monolithic composite parts provided the bonding zone has a stepped-lap geometry. This patent is based on a simple idea that no overlapping length is required between composite plies for load transfer except in the fiber directions of the plies (unidirectional or biaxial long fiber reinforcements with epoxy matrix). To prove this concept, we consider on one hand, a situation unusual in the literature by studying a composite specimen without fibers aligned along the main loading axis, and on the other hand, a classical situation of where the shape of the specimen is adapted to be studied by uniaxial tension tests. After different manufacturing steps, the studied specimen contains three zones representing both the influence of the total thickness of a repair patch, the stepped-lap area assembled with an adhesive film and the parent composite part. Basically, a simple parent structure consisting of 16 plies of UD Hexply® M21/35%/268/T700GC (close to Airbus composite raw materials on board in A380) is manufactured with a stacking sequence of [+45/−45/−45/+45/+45/−45/−45/+45]s. Then, the parent structure is machined by the Airbus Abrasive Water Jet machine and the final repair area has a stepped-lap geometry by overlapping successive plies of the same nature as the parent plate and after having previously applied an adhesive film (cured at 180 °C). Furthermore, 3 values of overlap length (respectively, 6, 8 and 13 mm) are investigated to include the mean value required by Airbus in the case of the use of the studied prepreg. After abrasive water jet machining of the composite parent part, repair patch manufacturing was performed according to Airbus requirements. The studied specimens were cut from the final plate (involving the parent plate, the stepped lap zone and the zone of the patch itself) and tested in an uniaxial tensile configuration with a loading direction shifted 45° with respect to the fiber direction. Furthermore, studying uniaxial tensile tests on multilayer-pasted interface is innovative in the literature. In this paper, it is shown that the stepped-lap area assembled with an adhesive film is not the weak link of the mechanical response but rather the parent area, i.e. the unrepaired monolithic composite. Numerical calculations confirm this proof of concept by underlying that the level of shear stress in the adhesive film, for these three overlapping values, is below the chosen limit value. These results show that the patch size reduction is possible.

Estilos ABNT, Harvard, Vancouver, APA, etc.

4

Psarras, Spyridon, Maria-Panagiota Giannoutsou e Vassilis Kostopoulos. "A Design Optimization Study of Step/Scarf Composite Panel Repairs, Targeting the Maximum Strength and the Minimization of Material Removal". Journal of Composites Science 8, n.º 7 (30 de junho de 2024): 248. http://dx.doi.org/10.3390/jcs8070248.

Texto completo da fonte

Resumo:

This study aimed to optimize the geometry of composite stepped repair patches, using a parametric algorithm to automate the process due to the complexity of the optimization problem and various factors affecting efficiency. More specifically, the algorithm initially calculates the equivalent strengths of the repaired laminate plate according to a max stress criterion, then calculates the dimensions of several elliptical repair patches, taking into account several design methods extracted from the literature. Next, it creates their finite element models and finally, the code conducts an assessment of the examined patch geometries, given specific user-defined criteria. In the end, the algorithm reaches a conclusion about the optimum patch among the designed ones. The algorithm has the potential to run for many different patch geometries. In the current research, five patch geometries were designed and modeled under uniaxial compressive loading at 0°, 45° and 90°. Overall, the code greatly facilitated the design and optimization process and constitutes a useful tool for future research. The results revealed that elliptical stepped patches can offer a near-optimum solution much more efficient than that of the conservative option of the circular patch, in terms of both strength and volume of healthy removed material.

Estilos ABNT, Harvard, Vancouver, APA, etc.

5

Kim, Yun-Hae, Kyo-Moon Lee, Seong-Jae Park, Kyung-In Jo e Soo-Jeong Park. "Repair and cryogenic mechanical properties with resin film infused (RFI) GFRP in out-of-autoclave processing". Modern Physics Letters B 34, n.º 07n09 (10 de março de 2020): 2040014. http://dx.doi.org/10.1142/s021798492040014x.

Texto completo da fonte

Resumo:

Prepreg technology generates air pockets at the interface of laminates under heating and pressurization. The air pockets cause defects in the through-thickness direction. This includes poor adhesion between layers, which degrades material properties. Therefore, in this study, cryogenic mechanical properties were compared to obtain uniform properties by using prepreg laminated and resin film infused glass fiber reinforced plastic (GFRP) composites (“PP-only” and “RF-only”, respectively) while maintaining the constituent contents of the fiber and polymer. Moreover, stepped repair was applied to extend the life of composites. The results demonstrated that the stiffness of the composites improved, and the brittleness increased in cryogenic environments. In the case of PP-only, numerous voids were observed inside the polymer, which showed higher bending strength than RF-only; however, it exhibited significantly lower interfacial bonding strength. When applied to secondary bonding of stepped repair, RF-only as repair layers showed high strength recovery rate in homogeneous materials, and not in heterogeneous materials. In contrast, the high strength PP-only as a parent material and RF-only as repair layers showed relatively good interfacial bonding strength due to primary damage in the PP of a parent material. Hence, the RF-only can be considered useful as a repair material.

Estilos ABNT, Harvard, Vancouver, APA, etc.

6

Mercado-Pagán, Ángel E., e Yunzhi Peter Yang. "Bridging the gap: engineering bone for skeletal injuries". Biochemist 40, n.º 1 (1 de fevereiro de 2018): 12–15. http://dx.doi.org/10.1042/bio04001012.

Texto completo da fonte

Resumo:

For years, mechanical fixators, grafts and cements have provided a surgical solution to bone injuries. However, the inherent restrictions of these treatments have prompted the search for newer options that can fully repair bone and restore its function. But, what are these approaches? What is the future of bone repair? Tissue engineering has stepped up efforts to tackle this difficult topic.

Estilos ABNT, Harvard, Vancouver, APA, etc.

7

Gillespie, David I., Andrew W. Hamilton, Robert C. Atkinson, Xavier Bellekens, Craig Michie, Ivan Andonovic e Christos Tachtatzis. "Defect Detection in Aerospace Sandwich Composite Panels Using Conductive Thermography and Contact Sensors". Sensors 20, n.º 22 (23 de novembro de 2020): 6689. http://dx.doi.org/10.3390/s20226689.

Texto completo da fonte

Resumo:

Sandwich panels consisting of two Carbon Fibre Reinforced Polymer (CFRP) outer skins and an aluminium honeycomb core are a common structure of surfaces on commercial aircraft due to the beneficial strength–weight ratio. Mechanical defects such as a crushed honeycomb core, dis-bonds and delaminations in the outer skins and in the core occur routinely under normal use and are repaired during aerospace Maintenance, Repair and Overhaul (MRO) processes. Current practices rely heavily on manual inspection where it is possible minor defects are not identified prior to primary repair and are only addressed after initial repairs intensify the defects due to thermal expansion during high temperature curing. This paper reports on the development and characterisation of a technique based on conductive thermography implemented using an array of single point temperature sensors mounted on one surface of the panel and the concomitant induced thermal profile generated by a thermal stimulus on the opposing surface to identify such defects. Defects are classified by analysing the differential conduction of thermal energy profiles across the surface of the panel. Results indicate that crushed core and impact damage are detectable using a stepped temperature profile of 80 ∘C The method is amenable to integration within the existing drying cycle stage and reduces the costs of executing the overall process in terms of time-to-repair and manual effort.

Estilos ABNT, Harvard, Vancouver, APA, etc.

8

Kozlov, V. B., A. B. Istomin e I. N. Gemba. "Repair and restoration of shafts, couplings, splined and keyed joints". Glavnyj mekhanik (Chief Mechanic), n.º 7 (11 de junho de 2021): 32–42. http://dx.doi.org/10.33920/pro-2-2107-03.

Texto completo da fonte

Resumo:

The article provides an overview of the methods of restoration and repair of various parts of the equipment: shafts, couplings, splined and keyed joints. Recommendations on the choice of methods, equipment and tools are given. In case of wear, the keyway is repaired by welding the face with subsequent milling. At the same time, the keyway size set by the standard is maintained. Such repairs are also possible: the keyway is expanded and deepened, completely eliminating the traces of wear, after which a stepped key is made to it. However, with such repairs, a high-quality connection is not provided and, therefore, it is used in exceptional cases (during inspections and ongoing repairs). When repairing keyed joints, the worn keyed joints are not repaired, but new ones are made, fitting them to achieve a firm contact with the side surfaces of the grooves of the connected parts. The exception is the taper keys: they are driven into the keyway with a hammer blow so that they are jammed in height. The taper key should also be hammered in such a way that, when loosened, it can be deposited. Between the head of the key and the end of the part, there must be a distance equal to the height of the key. The connection with the help of splines is used for fixing gears, gear wheels, and bushings on the shafts. It has a number of advantages over other types of connection. The component parts of this joint are more easily centered. This significantly reduces mechanical deformations at the bushing boundary. During operation, under the influence of various loads, the spline joint loses its properties. In this case, the splines or grooves in which they are placed are restored. Splines of small rollers are usually not repaired; the parts with worn splines are mostly replaced with new ones. Such work is carried out in specialized workshops. In some cases, the repair and restoration of such products is carried out in a small workshop, but equipped with the necessary machines.

Estilos ABNT, Harvard, Vancouver, APA, etc.

9

Ibyldaev, M. H. "PRINCIPLES OF PRESSURE REHABILITATION OF STANDARD SHAFTS". MECHANICS & TECHNOLOGIES, n.º 3 (30 de setembro de 2023): 98–104. http://dx.doi.org/10.55956/spca7436.

Texto completo da fonte

Resumo:

The reliability and performance indicators of the known methods currently used in the country's repair industry for the restoration of stepped shafts cannot compete with the indicators of new parts. The most progressive method of restoring step shafts is the method of hot volume stamping. The technical characteristics of pressure-remanufactured parts indicate that their quality is not inferior to serial parts.

Estilos ABNT, Harvard, Vancouver, APA, etc.

10

Xu, Jian Xin, Chen Dou e Ding He Li. "Stress-Based Health Assessment of Composite Open-End Cylindrical Laminated Shell with Stepped-Lap Repairs". Advanced Materials Research 393-395 (novembro de 2011): 297–303. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.297.

Texto completo da fonte

Resumo:

A three-dimensional finite element model was created in PATRAN to perform stress distribution into the influence of disbonded adhesive in stepped-lap repairs of composite open-end cylindrical laminated shell. Extracted and studied the value of the stress on every ply, and every node, ordered by the X coordinate. A study has been presented that the rim of patch is greatly affected by disbonded types, however, the central area of the patch is less affected relatively, especially between ±20mm, that the diameter is equal to the diameter of the damage, the stresses are flatly changed. And for the whole model, the maximum is in the sixth layer, so that the internal area is the most easily to be damaged. Therefore, it should be force on this special area in experimental health assessment such as using piezoelectric elements. It could provide certain maintenance basis for the future practical repair.

Estilos ABNT, Harvard, Vancouver, APA, etc.

11

ZHENG, Shengwu, Xiongmei HUANG, Jing ZHUANG, Ling ZHANG, Genhui LIN e Yu YANG. "Expanded Forehead Stepped Flaps for Delayed Three-Stage Repair of Midface Skin Lesions". Chinese Journal of Plastic and Reconstructive Surgery 2, n.º 4 (dezembro de 2020): 212–56. http://dx.doi.org/10.1016/s2096-6911(21)00040-6.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

12

Bendemra, Hamza, Paul Compston e Phillip J. Crothers. "Optimisation study of tapered scarf and stepped-lap joints in composite repair patches". Composite Structures 130 (outubro de 2015): 1–8. http://dx.doi.org/10.1016/j.compstruct.2015.04.016.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

13

MacLellan, Jennifer, e Adelaide Aduboffour. "Confidence and Competence: Evaluation of a Stepped Perineal Suturing Simulator Package". Practising midwife 26, n.º 4 (1 de abril de 2023): 8–13. http://dx.doi.org/10.55975/grcn3173.

Texto completo da fonte

Resumo:

Perineal trauma following birth is extremely common. However, midwives continue to report a lack of confidence in perineal assessment and repair. Dominance of online training and lack of support in practice are some of the possible reasons for practitioners to avoid suturing. Simulation training is an effective method of teaching midwifery skills but pelvic models and suturing simulators have been described as not fit for purpose. A mixed methods evaluation of a three-model stepped simulation package of responsive but robust models show that quality simulators and a supportive environment to practise increase midwives’ confidence in perineal suturing.

Estilos ABNT, Harvard, Vancouver, APA, etc.

14

Park, Gene, e Steven Vogel. "Japan in 2006: A Political Transition". Asian Survey 47, n.º 1 (janeiro de 2007): 22–31. http://dx.doi.org/10.1525/as.2007.47.1.22.

Texto completo da fonte

Resumo:

Prime Minister Koizumi Junichiro stepped down in September 2006 after a five-year term in which he reshaped Japanese politics by undermining his own party's political machine, stretched the constraints on Japan's military role, and promoted a program of ““structural”” economic reform. In his final year in office, he confronted a backlash against his economic reform program and presided over a chill in relations with China and South Korea. Abe Shinzo replaced Koizumi, pledging to repair relations with Japan's neighbors and to promote a pro-growth economic strategy.

Estilos ABNT, Harvard, Vancouver, APA, etc.

15

Zaremba, David, Christian Biskup, Thomas Heber, Nico Weckend, Werner Hufenbach, Frank Adam, Friedrich-Wilhelm Bach e Thomas Hassel. "Repair Preparation of Fiber-Reinforced Plastics by the Machining of a Stepped Peripheral Zone". Strojniški vestnik – Journal of Mechanical Engineering 58, n.º 10 (15 de outubro de 2012): 571–77. http://dx.doi.org/10.5545/sv-jme.2012.305.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

16

Khan, Sohail M. A., F. Benyahia, B. Bachir Bouiadjra e A. Albedah. "Analysis and Repair of Crack Growth Emanating from V-notch under Stepped Variable Fatigue Loading". Procedia Engineering 74 (2014): 151–56. http://dx.doi.org/10.1016/j.proeng.2014.06.240.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

17

Rahman, Alexandre. "Remediation Technology for the Restoration of Polluted Soil". Science Insights 41, n.º 2 (29 de julho de 2022): 593–97. http://dx.doi.org/10.15354/si.22.re071.

Texto completo da fonte

Resumo:

One of the most serious environmental issues is soil pollution. With the increase in contaminated sites, how to safely and effectively remediate these contaminated soils has become an urgent environmental problem in our country. This paper summarizes the most commonly used remediation technologies and research progress for contaminated soil in the United States and abroad, including physical remediation, chemical remediation, and bioremediation. Each repair technique has advantages and disadvantages. To get around the problems with a single method and make the most of the benefits of different remediation technologies, it was suggested that research and development of comprehensive remediation technologies for contaminated soils be stepped up.

Estilos ABNT, Harvard, Vancouver, APA, etc.

18

Liu, Gui Hua, Zhi Jiang, Yi Bian, Guang Sheng Ren e Chun Guo Xu. "Inflluence of Tool Wear on Center Defects of the Workpiece during Cross Wedge Rolling Process". Advanced Materials Research 154-155 (outubro de 2010): 1779–82. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.1779.

Texto completo da fonte

Resumo:

Cross wedge rolling (CWR) technology, which is a new metal forming process to produce stepped shaft in forging industry, has developed rapidly in the last decades. Tool wear is a key factor to influence products’ quality during CWR process in practice. Basing on the analysis of characteristic of the tool wear, the similar outline dimension of the worn tool in service is obtained by blocking up the end of the tool. A series of experiments are completed to research the influence of the tool wear on the center defects of the workpiece, and the available method to repair the worn tools is brought forward.

Estilos ABNT, Harvard, Vancouver, APA, etc.

19

Kondratiev, Andrii, Václav Píštěk, Lina Smovziuk, Maryna Shevtsova, Anna Fomina e Pavel Kučera. "Stress–Strain Behaviour of Reparable Composite Panel with Step-Variable Thickness". Polymers 13, n.º 21 (5 de novembro de 2021): 3830. http://dx.doi.org/10.3390/polym13213830.

Texto completo da fonte

Resumo:

There is an urgent problem of finding an economically viable method of maintenance and restoration of the bearing capacity of structures of various applications. Repair of structures with patches made of polymeric composite materials is one of the most promising repair technologies. However, an improper choice of parameters of the composite patch leads to unjustified increase in the structure mass and the cost of its further operation. These situations result from the lack of reliable methods for developing the repair process, which take into account the influence of the patch geometry and conditions for performance of repair works on the bearing capacity of the repaired structure. The mathematical model of the reparable composite shell–type panel taking into account inhomogeneity of transverse shear deformations at stepped variation of its thickness has been developed. In contrast to the classical theory of layered shells, the model allows simplifying a three-dimensional problem by setting of the displacement field on the layers’ interfaces and their linear interpolation over thickness of the panel, as well as considering the transverse shear deformations resulting from the strength, temperature, or shrinkage loading. According to results, the maximum rise in stresses in the case of a notched panel occurs in the weakened layer, and it is from this layer the failure of the structure will start. In the event of the patch, the panel surface opposite the reinforcement is the most loaded (i.e., susceptible to failure) surface. To confirm the reliability of the developed model, we compared the analytical calculations with the results of experimental and numerical studies of the deformed state of a panel of step–variable thickness by the method of holographic interferometry and modelling by the finite element method. Displacement fields available from experiments correspond to the predicted theoretical results. The resulting maximum error does not exceed 7%. The data obtained during numerical modelling allowed us to conclude that the accuracy of theoretical calculations is sufficient for engineering practice. Results of the work can be used to solve the practical problems such as determination of stress–strain behaviour of a damaged structure or structure after repair, specification of the permissible delamination dimensions, and defining of parameters of the bonded repair process.

Estilos ABNT, Harvard, Vancouver, APA, etc.

20

Damghani, Mahdi, Stephan Bolanos, Amandeep Chahar, Jason Matthews, Gary A. Atkinson, Adrian Murphy e Timothy Edwards. "Design, novel quality check and experimental test of an original variable length stepped scarf repair scheme". Composites Part B: Engineering 230 (fevereiro de 2022): 109542. http://dx.doi.org/10.1016/j.compositesb.2021.109542.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

21

Shrikanth, B., M. Krishna e H. A. Mithun. "Effect of bonded stepped and scarf repair on impact damaged glass fibre reinforced polymer composite properties". International Journal of Materials Engineering Innovation 12, n.º 3 (2021): 234. http://dx.doi.org/10.1504/ijmatei.2021.10039982.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

22

Mithun, H. A., M. Krishna e B. Shrikanth. "Effect of bonded stepped and scarf repair on impact damaged glass fibre reinforced polymer composite properties". International Journal of Materials Engineering Innovation 12, n.º 3 (2021): 234. http://dx.doi.org/10.1504/ijmatei.2021.116946.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

23

Li, Dinghe, Guanghui Qing e Yanhong Liu. "A three-dimensional semi-analytical model for the composite laminated plates with a stepped lap repair". Composite Structures 93, n.º 7 (junho de 2011): 1673–82. http://dx.doi.org/10.1016/j.compstruct.2011.01.013.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

24

Tenchev, Rosen T., e Brian G. Falzon. "An Experimental and Numerical Study of the Static and Fatigue Performance of a Composite Adhesive Repair". Key Engineering Materials 383 (junho de 2008): 25–34. http://dx.doi.org/10.4028/www.scientific.net/kem.383.25.

Texto completo da fonte

Resumo:

Experimental static and fatigue tension-tension tests were carried out on 5HS/RTM6 composite intact coupons and coupons incorporating adhesively-bonded (FM300-2) stepped flush joints. The results show that the adhesive joint, which is widely used in repairs, significantly reduces the static strength as well as the fatigue life of the composite. Both, the static and the fatigue failure of the ‘repaired’ coupons occur at the adhesive joint and involve crack initiation and propagation. The latter is modelled using interface finite elements based on the decohezive zone approach. The material degradation in the interface constitutive law is described by a damage variable, which can evolve due to the applied loads as well as the number of fatigue cycles. The fatigue formulation, based on a published model, is adapted to fit the framework of the pseudotransient formulation that is used as a numerical tool to overcome convergence difficulties. The fatigue model requires three material parameters. Numerical tests show that a single set of these parameters can be used to recover, very accurately, the experimental S-N relationship. Sensitivity studies show that the results are not mesh dependent.

Estilos ABNT, Harvard, Vancouver, APA, etc.

25

Petrica, Dan. "ROBERT MUGABE’S SIEGE ON JUSTICE: THE DEMISE OF THE SADC TRIBUNAL AND SOUTH AFRICA’S JUDICIAL REPARATIONS FOR ZIMBABWEANS". AGORA INTERNATIONAL JOURNAL OF JURIDICAL SCIENCES 14, n.º 2 (11 de janeiro de 2021): 61–67. http://dx.doi.org/10.15837/aijjs.v14i2.4159.

Texto completo da fonte

Resumo:

This research piece investigates how Zimbabwe’s government was successful in rendering a regional court obsolete, with the implicit approval of South Africa. It also tackles how South Africa’s judiciary stepped in to fill the resulting jurisdictional void by enforcing a distinctively detrimental decision on Robert Mugabe’s regime on a particularly controversial subject for both countries: namely, land restitution. In achieving the above, South Africa’s judicial branch managed to repair some of its executive’s missteps in handling Zimbabwe’s descent to authoritarianism — one brimming with human rights infringements and attacks on the rule of law. The article lies at the intersection of two humanities: political science and law, drawing themes and research methods from each. Still, it is not limited to practitioners from the said fields, being specifically constructed to be accessible to any interested reader.

Estilos ABNT, Harvard, Vancouver, APA, etc.

26

Herman, James P., Mark R. Harwood e Josh Wallman. "Saccade Adaptation Specific to Visual Context". Journal of Neurophysiology 101, n.º 4 (abril de 2009): 1713–21. http://dx.doi.org/10.1152/jn.91076.2008.

Texto completo da fonte

Resumo:

When saccades consistently overshoot their targets, saccade amplitudes gradually decrease, thereby maintaining accuracy. This adaptive process has been seen as a form of motor learning that copes with changes in physical parameters of the eye and its muscles, brought about by aging or pathology. One would not expect such a motor-repair mechanism to be specific to the visual properties of the target stimulus. We had subjects make saccades to sudden movements of either of two targets—a steadily illuminated circle or a flickering circle—one of which stepped back during each saccade it elicited, simulating the effect of a hypermetric saccade. Saccade gain (saccade amplitude/target amplitude) decreased by 15% for the target that stepped back versus 6% for the target that did not step back. Most of the change in gain between successive blocks of trials of each type occurred on the first saccade of the block, decreasing by 0.12 on the first trial of a step-back block and increasing by 0.1 on the first trial of a no-step-back block. The differential adaptation of the two targets required postsaccadic feedback of both target types, as shown in a separate experiment, in which saccades to only one target received feedback, and the gain did not differ between the two target types. This demonstration that a context defined by a visual stimulus can serve as an effective cue for switching saccade gain between states suggests that saccade adaptation may have a heretofore unsuspected dimension of adaptability.

Estilos ABNT, Harvard, Vancouver, APA, etc.

27

Brieskorn, Leander, e Wolfgang Hintze. "Automated removal of carbon fiber reinforced plastic layers for the repair by adhesive bonding". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 234, n.º 13 (5 de agosto de 2020): 2011–22. http://dx.doi.org/10.1177/0954410020947913.

Texto completo da fonte

Resumo:

For the industrial repair of carbon fiber reinforced plastics (CFRP), scarfing is used to re-establish the load path. In the industry today, the state of the art removal of CFRP layers for a repair process is done mainly manually, leading to a time-consuming process. Therefore, an automation of this process is desirable. Today, vacuum suction blasting is used to pre-treat CFRP surfaces only for the superficial removal of impurities or the removal of the cover layer before bonding. With the common used blasting agents and nozzle geometries, the even removal of larger areas together with the fiber was not possible. This work shows that the technology of vacuum suction blasting was adapted to be used as an automated scarfing method. A combination of blasting parameters, especially the nozzle geometries together with a blasting agent were found to be able to remove CFRP layers precisely, detecting and correcting errors in-line with a line scanner-measuring unit. The presented method allows treating large-scale surfaces, scarfing the area one single layer at a time, increasing the removal rate in comparison to common blasting. With vacuum suction blasting the grinding dust emissions and process forces are low, post cleaning or further surface activation are not necessary and the removal results can directly be controlled. Challenges still exist with inaccurate removal due to interruptions in the blasting program and the generation of sharp edges for a stepped scarf.

Estilos ABNT, Harvard, Vancouver, APA, etc.

28

Hudz, Hustav, Mykhailo Нlobchak, Roman Pelo e Oleg Kotsjumbas. "Comparative evaluation of dynamics and fuel efficiency indicators of the car with robotic stepped transmission under condition of different diameters of engine cylinders". Vehicle and electronics. Innovative technologies, n.º 19 (1 de maio de 2021): 35–40. http://dx.doi.org/10.30977/veit.2021.19.0.35.

Texto completo da fonte

Resumo:

Problem. Repair dimensions method regulates increment of cylinders by the means of mechanical treatment, which leads to increasing of working volume of the engine. This will cause a change of dynamics and fuel-efficiensy indicators of the car with the certain type of transmission. Goal. The goal is to comparatively evaluate dynamism and fuel-efficiency of automotive vehicle category N2 with two options of engines, which have nominal and repair cylinder sizes. The riding cycle of the cars with robotic stepped gearbox was researched, that is without breaking of force stream while switching gears. Methology. Imitative simulation of cars riding cycle, according to standard, was conducted with the help of Matlab Simulink software. Because of the fact that mathematical model of cars movement during mentioned cycle is based on elementary dependencies, for its realization the only basics avialable blocks of the sofware package were used. The flowchart is given in the paper. Results. Simulation of riding cycle of N2 – category automotive vehicle with robotic gearbox was conducted at full engine’s capacity while running-up. Obtained results have shown that engines with repairment sizes have advantage in dynamism indicators, engines with nominal cylinder sizes have advantages in fuel-efficiency. Originality. For obtaining of comparative evaluation of dynamics and fuel-efficiency indicators of the car with robotic gearbox with different engines, the imitation simulation of riding cycle, according to standarts, was used with the help of Matlab Simulink software. Practical value. Application of the repairment sizes method upon the engine’s cylinder liners has shown improvement of dynamics indicators of car with robotic transmission, which will improve its productivity under excessive engines work conditions.

Estilos ABNT, Harvard, Vancouver, APA, etc.

29

Fadel, Mohei M., Hesham M. Gawish e Mohamed A. Elsheikh. "Clinical and radiological outcomes of arthroscopic subcoracoid decompression for idiopathic coracoid impingement, a stepped approach". International Journal of Research in Orthopaedics 7, n.º 2 (23 de fevereiro de 2021): 203. http://dx.doi.org/10.18203/issn.2455-4510.intjresorthop20210614.

Texto completo da fonte

Resumo:

Background: Idiopathic subcoracoid impingement is considered now as a well-established cause of anterior shoulder pain. There are multiple techniques reported for management of subcoracoid impingement. Open decompression and reattachment of conjoint tendon as well as arthroscopic resection of coracoid tip. The aim of this study was to evaluate the results of arthroscopic stepwise approach for management of idiopathic coracoid impingment.Methods: This prospective therapeutic case series study included 26 consecutive patients suffering from anterior shoulder pain and were diagnosed as subcoracoid impingement. All cases were evaluated preoperatively and followed up for 12 months after surgery both clinically and radiologically. Arthroscopic subcoracoid decompression, coracoplasty and arthroscopic repair of partial subscapularis tear if present were done for all cases.Results: The mean age at the time of surgery was 45.3±5.4years. At the final follow up, the mean VAS score improved significantly to 0.8±0.8points postoperatively (p<0.01). The mean Constant score improved significantly to 87.8±7.8 at the final follow-up (p<0.001). The mean UCLA score improved significantly to 32.1±2.4 at the end of follow-up (P<0.001)Conclusions: Coracoid impingement should be in mind when evaluating any patient with anterior shoulder pain. The arthroscopic management in form of bone, bursal and tendon procedures (triple attack) is a good treatment to relieve clinical symptoms with excellent patient reported outcomes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

30

Chervov, V. V. "The method to remove parts from the multi-step oil well centrifugal pump housing on a workbench". Interexpo GEO-Siberia 2, n.º 4 (18 de maio de 2022): 21–28. http://dx.doi.org/10.33764/2618-981x-2022-2-4-21-28.

Texto completo da fonte

Resumo:

Repair of centrifugal oil pumps requires their total tear-down, with removal of steel parts from the cylindrical housing made of thick-walled steel tubes. This paper describes the technology of removal of steel parts from the tube using an air-driven hammer with a piston of relatively small weight of 40 kg. The complete tear-down of the deep-well centrifugal pump is implemented using a facility with a guiding frame. The frame accommodates the mutually appressed air-driven hammer, a nozzle with a conical seating surface, a tube section with a side window and a stepped flange adaptor. The latter is pressed to the end face of the pump housing. The other end of the housing is butted on the energy sink fastened on the guiding frame. The described facility has a rod passed through the open end hole in the energy sink and along the opening of the housing, which interacts with the parts in the housing via one end and with the drive via the other end.

Estilos ABNT, Harvard, Vancouver, APA, etc.

31

Begum, Nurun Nahar Fatema, Md Ferdousur Rahman Sarkar, Md Ashfaque Ahemmed Khan e Mohammad Nazmul Islam Bhuiyan. "Successful multiple Percutaneous Interventions and Biventricular Surgical Repair in a Child with Pulmonary Atresia with Intact Ventricular Septum— A Case Report". Cardiovascular Journal 13, n.º 1 (7 de dezembro de 2020): 81–85. http://dx.doi.org/10.3329/cardio.v13i1.50569.

Texto completo da fonte

Resumo:

Pulmonary atresia (PA) with intact ventricular septum is a rare, heterogeneous congenital heart defect with varying degrees of right ventricular and tricuspid valve hypoplasia and wide spectrum clinical features. Initial treatment at presentation is to establish systemic to pulmonary shunt or ductus stenting. The treatment options i.e. biventricular, one and half ventricular or one ventricular repair are often dictated by the degree of development of the tricuspid valve and right ventricle. X, 11 years old teenage girl got admitted to Combined Military Hospital (CMH) Dhaka at 5 months of age with severe cyanosis, respiratory distress, acidosis and shock. After immediate stabilization and work up, she was diagnosed as pulmonary atresia with intact ventricular septum, flapped atrial septal defect (ASD) and a small patent ductus arteriosus (PDA). On urgent basis, stenting of PDA done with 3.5 X 11 mm coronary stent at cardiac catheterization laboratory. Her SPO2 stepped up to 90 % from base line SPO2 from 50% following procedure. At 15 months of age she underwent intracardiac repair with short trans annular patch and ASD left open as a vent for RV. On follow up her ASD was getting larger and became desaturated and symptomatic. She was followed up for the right ventricular (RV) and tricuspid valve growth and ASD shunt. As her RV was developing nicely during follow up and achieved TV z score –1, ASD device closure was done with 18 mm Amplatzer ASD device at 5 years of age. She is now asymptomatic and thriving well. Cardiovasc. j. 2020; 13(1): 81-85

Estilos ABNT, Harvard, Vancouver, APA, etc.

32

Camassa, José Arthur De Abreu, Leonardo Augusto Lopes Muzzi, Fernando Yoiti Kitamura Kawamoto, Camila Cardoso Diogo, Ruthnéa Aparecida Lázaro Muzzi, Raquel De Lima e Flávia Maria De Oliveira Borges Saad. "Femoral Fracture Repair in a Ferret (Mustela putorius furo)". Acta Scientiae Veterinariae 44, n.º 1 (16 de janeiro de 2016): 5. http://dx.doi.org/10.22456/1679-9216.84718.

Texto completo da fonte

Resumo:

Background: Ferrets (Mustela putorius furo) are increasingly popular as pets. They require similar medical and surgical care as small animals, and orthopedic lesions are more and more common. Fracture diagnosis is based on history, orthopedic exam, and diagnostic imaging. The preferred treatment for femur fractures is surgery, which has a favorable outcome in the majority of cases. However, surgical fracture repair in ferrets can be challenging due to the small size of the bones. The objective of thispaper is to report the surgical repair of a femoral fracture in a ferret using an external skeletal fxation system type IA connected to an intramedullary pin (tie-in confguration).Case: An adult ferret was referred to the veterinary hospital after being stepped on. The ferret was diagnosed with an oblique diaphyseal fracture of the left femur and surgery was recommended. Open fracture reduction was performed with a 1 mm in tramedullary pin (Kirschner wire) placed in a retrograde direction into the proximal bone segment. After fracture reduction, the intramedullary pin was inserted into the distal bone segment. The external skeletal fxator type IA was created by the insertionof a 1.5 mm Schanz pin into the distal diaphysis and another, also 1.5 mm, inserted into the proximal metaphysis, both percuta neously. The three pins were connected externally to an aluminum bar with the aid of three staples to form a tie-in system. Rest and restriction of activity were recommended during the frst month after surgery. The ferret recovered well and, at 120 days, orthopedic and radiographic exams showed complete fracture healing. The implant was removed and no functional changesrelated to ambulation were observed.Discussion: The orthopedic knowledge applied to ferrets commonly originates in procedures performed on cats and dogs. Overall,the main objective when dealing with fractures is to stabilize the broken bone to allow early ambulation. Due to the location and type of fracture, an external immobilization was contraindicated in this case. A plate was considered, but the small diameter of the femur and the consequent risk of iatrogenic fractures made this option not feasible. Therefore, the external skeletal fxator in a tie-in confguration was selected. This method permitted control of the forces acting on the fracture site and had the advantage of low cost and ease of application and removal. Nevertheless, the vast musculature that covers the femur could hinder the use ofthe external pins and lead to discomfort. The method has been reported with some changes in ferrets, though with inconclusive results due to lack of follow-up. In the present report, a less rigid method, type I, was used since types II and III have a biplanar confguration and were thus inadequate due to the possible contact between the fxator and the abdominal or inguinal region. The precautions taken during placement of the implant were the same as in cats and dogs since their anatomy follows the same pattern. The implant was rigid, light, and effective, allowing early weight-bearing on the affected limb without discomfort to the patient. As such, the external fxator type IA connected to the intramedullary pin in a tie-in confguration was an effective method for the treatment of the oblique diaphyseal femoral fracture in this ferret. Although it is not the recommended method for this type of fracture in cats and dogs, there were no complications in the ferret, with complete fracture healing and return tofunction of the affected limb. Since there has yet to be a consensus on the recommended procedures in these animals, reports of this nature are important due to the growing number of ferret patients in veterinary practice.Keywords: ferret, osteosynthesis, bone fxation, repair of fractures.

Estilos ABNT, Harvard, Vancouver, APA, etc.

33

Soda, Yoshinori, Shingo Ohkawa, Toshiya Kano, Mitsuhiro Nakamura e Nobuo Adachi. "Isolated Lateral Collateral Ligament Injury of the Knee in a Judo Athlete: A Surgical Case Report". Journal of Orthopaedic Case Reports 12, n.º 9 (2022): 84–87. http://dx.doi.org/10.13107/jocr.2022.v12.i09.3328.

Texto completo da fonte

Resumo:

Introduction: We report a rare case of surgical treatment for an isolated lateral collateral ligament (LCL) injury of the knee that was difficult to correctly diagnose considering physical findings alone of a judo athlete. Case Report: The 27-year-old man complained of pain on the lateral side of the right knee and discomfort and balance instability when climbing and descending stairs. During a judo match, he stepped on his right foot to prevent his opponent’s waza (techniques), causing forced varus on his knee in a slight flexion position. His right knee showed no apparent sway in the manual test, but pain around the fibular head was induced in the figure-of-four position, and the LCL could not be palpated. Joint instability was not detected on varus stress roentgenography, but magnetic resonance imaging showed signal changes and an abnormal course in the fibula head insertion at the distal part of the LCL. Although no instability was observed objectively, clinical findings diagnosed LCL as an isolated injury, and surgical treatment was performed. Six months after the operation, his symptoms improved, and he resumed competing in judo. Conclusion: To correctly diagnose an isolated LCL injury of the knee, it is important to consider patient history and physical findings. Repair of the injury could improve subjective symptoms, such as pain, discomfort, and balance instability, even if objective instability is not observed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

34

Boyarshinov, Mikhail, Konstantin Dongauser e Marat Bekmansurov. "NUMERICAL SIMULATION OF WELDING DISTORTION IN LASER METAL DEPOSITION ADDITIVE MANUFACTURING PROCESS". Perm National Research Polytechnic University Aerospace Engineering Bulletin, n.º 68 (2022): 30–37. http://dx.doi.org/10.15593/2224-9982/2022.68.04.

Texto completo da fonte

Resumo:

This article discusses the modeling of the stress-strain state of products during laser powder surfacing using the example of a stepped tubular sample. To calibrate the model, a number of experiments were carried out using an additive powder with a fractional composition of 40–80 μm. During laser powder surfacing of samples, two-point thermometry was carried out, which is necessary for the subsequent calibration of the temperature problem. Powder surfacing was carried out in one layer with pauses between the deposited paths according to the surfacing modes. Helium and argon were used as shielding gases. The creation of an applied tool for the preliminary numerical assessment of warpage and residual stresses in blanks and DSE before carrying out repair technological operations using the powder laser cladding method, which allows for prompt approximate calculations, was the main task of the work. In the model, the element birth/death method was considered, which makes it possible to implement the appearance of hardfacing bodies and is the most convenient in this case. Warping modeling was carried out by dividing the welded part into tracks, which, in turn, are divided into hardfacing bodies. The next stage is the heatingand cooling of each elementary body along the surfacing trajectory, instead of modeling a moving heat source. Command inserts allow you to adjust the surfacing trajectory using automatic numbering of elementary bodies. The proposed technique makes it possible to quickly preprocess the problem and obtain sufficiently accurate calculation results in a short time. The results of modeling and real laser powder surfacing were compared. Verification of the developed model was carried out using the digitized outer surface of the existing experimental samples after surfacing. Calculations show sufficient computational accuracy of the model, however, the use of high-temperature properties of the powder material will reduce the calculation error.

Estilos ABNT, Harvard, Vancouver, APA, etc.

35

Xu, Jian Xin, Lu Chun Zhao e Ding He Li. "Finite Element-Based Parametric Investigations of the Stepped-Lap Repairs to Laminated Cylindrical Shell". Applied Mechanics and Materials 90-93 (setembro de 2011): 2682–90. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.2682.

Texto completo da fonte

Resumo:

A parametric finite element (FE) model was developed to allow a broad investigation into the influence of various parameters, such as load conditions, stacking sequence and the number of steps on the performance of the stepped-lap repairs in composite laminated cylindrical shells. And the peak stresses determined with respect to changes in stacking sequence and the number of steps. Furthermore, the adhesive stress distribution resulting from joining mismatched laminate cylindrical shells was investigated. The results of this investigation provide further insight into the stresses that develop in stepped repairs of composite structures under load. This insight may lead to improve design and analysis techniques of stepped repairs in composite structures.

Estilos ABNT, Harvard, Vancouver, APA, etc.

36

Wang, C. H., V. Venugopal e L. Peng. "Stepped Flush Repairs for Primary Composite Structures". Journal of Adhesion 91, n.º 1-2 (5 de setembro de 2014): 95–112. http://dx.doi.org/10.1080/00218464.2014.896212.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

37

Akulenko, N. M. "Pathological Changes in the Liver Parenchyma of Reptiles as a Factor Influencing the Processes of Hematopoiesis (on the Example of Lacertidae: Eremias arguta)". zoodiversity 58, n.º 5 (2024): 429–34. http://dx.doi.org/10.15407/zoo2024.05.429.

Texto completo da fonte

Resumo:

The influence of liver repair processes on haematopoiesis in scaly reptiles, in particular the steppe runner Eremias arguta (Pallas, 1773) is considered. Specimens with maximum and minimum liver parenchyma damage were selected from the same biotope and their liver myelogram indices were compared. It was shown that macrophage activation during liver repair stimulates lymphoid and myeloid haematopoietic progenitor cells in steppe runners. On the contrary, differentiation of erythroid cells at the normocyte stage is somewhat reduced, probably due to lack of resources.

Estilos ABNT, Harvard, Vancouver, APA, etc.

38

Liu, Bin, Nongyue Gao, Bosen Tang, Yidi Gao, Peng Jin, Zhixian Lu e Zaiguo Fu. "Progressive damage behaviors of the stepped-lap composite joints under bending load". Journal of Composite Materials 54, n.º 14 (21 de novembro de 2019): 1875–87. http://dx.doi.org/10.1177/0021998319889119.

Texto completo da fonte

Resumo:

Due to the high connecting strength and excellent load-transferring efficiency, the adhesively stepped-lap composite bonding has been widely used as joints and repairs in advanced aircraft structures. In the service life of composite structures, they frequently subject to bending loads which are rarely reported by the available reference. Hence, in this paper, three-point and four-point bending experiments are performed on composite stepped-lap structures. Typical damage mode of adhesive on the stepped surface has been found in experiments. And the failure of composite fiber, matrix, interlamination and adhesive materials appeared as competitive behavior. Furthermore, numerical models of stepped-lap composite joints, which used cohesive zone model and 3D Hashin criteria to simulate the inter- and intralaminar damages, were utilized to predict the bending strength and progressive damage. The FEM model, based on progressive damage method, captured the detailed failure as the loading displacement was increasing. The simulation results of load displacement and damage have good agreement with the experiments.

Estilos ABNT, Harvard, Vancouver, APA, etc.

39

Попиков, Petr Popikov, Максименков e Alexey Maksimenkov. "New bandsaw equipment for small businesses of agriculture and forestry". Forestry Engineering Journal 4, n.º 2 (10 de junho de 2014): 159–66. http://dx.doi.org/10.12737/4521.

Texto completo da fonte

Resumo:

New design of energy-efficient, high-speed compact band saw machine for small businesses of agriculture and forestry of forest-deficient steppe and steppe zones of Russia is proposed and justified, providing an increase in the quality and output of business sawn timber for cutting low-quality wood. From domestic and foreign counterparts’ machine differs by simplistic and reliable cutting unit, low power of technological process, capablity of providing high-speed cutting mode, lack of complex electronic circuits, complicating repair and increasing its value.

Estilos ABNT, Harvard, Vancouver, APA, etc.

40

Chushkina, Iryna, Nataliia Maksymova, Dmytro Pikarenia e Olga Orlinska. "Research by Geophysical Methods of Hydraulic Structures of Water Management Purpose". Journal of Lumbini Engineering College 4, n.º 1 (7 de dezembro de 2022): 28–32. http://dx.doi.org/10.3126/lecj.v4i1.49362.

Texto completo da fonte

Resumo:

Yield growth in the Southern Steppe is impossible without irrigation with the introduction of mineral and organic fertilizers, so the repair, restoration, and construction of new irrigation networks are one of the main tasks of regional and district water management. For the repair of water management networks, regulation of pools of irrigation systems it is necessary to use inexpensive effective methods of the establishment of their technical condition. Such methods are geophysical, which allow to identify the areas of filtration, flooding, violations of protective screens in the control pools of irrigation systems. The necessity of localization of areas of filtration water losses to concentrate repair and restoration works in the most disturbed zones is scientifically substantiated, which will significantly reduce the cost of time and money and increase the overall efficiency of the structure.

Estilos ABNT, Harvard, Vancouver, APA, etc.

41

Strilets, Oleh, Volodymyr Malashchenko e Sylwester Kłysz. "Review and complement of methods for changing the movement speed of mechanisms and machines elements". Ukrainian Journal of Mechanical Engineering and Materials Science 7, n.º 1-2 (2021): 9–22. http://dx.doi.org/10.23939/ujmems2021.01-02.009.

Texto completo da fonte

Resumo:

In mechanical drives of machines there is a need to control changes in the speed of their actuators. Stepped and stepless gearboxes are used for this purpose. Known speed control devices have many disadvantages that adversely affect the durability and reliability of drive components and machines in general. These include the design complexity, high material consumption, automation complexity, dynamic loads during transitions from one speed to another, intensive wear of parts due to the friction connections use. The purpose of the work is to develop an algorithm for determining the kinematic, power parameters and dimensions when designing speed change devices through the ring gear of a gear differential with a rotary stopper in the form of a closed-loop hydraulic system based on authors’ previous computer-theoretical research and classical scientific advices. To solve these problems analytical expressions and graphs have been obtained for the relationship between speeds of gear differential links, the efficiency has been determined by the method of potential power – based on friction losses in each gearing. With the help of computer modeling of analytical expressions, using the MATLAB software, graphical dependences of efficiency have been obtained, which made it possible to evaluate the accomplishment of the gear differential in terms of energy consumption and possible self-braking. Based on Lagrange's theory, a dynamic model of a speed change device with a ring gear control has been constructed and a solution of the obtained system of equations has been proposed. The 3D modeling of the device has been executed and at the final choice of the optimum variant of model, after some specifications, development of technical documentation can be started. The results obtained have practical application at the stage of development and design of new speed control devices through the ring gear, allow to evaluate the operation of gear differentials in terms of energy consumption and self-braking and are the basis for further research. The graphical dependences obtained for the efficiency of the gear differentials clearly allow us to trace the change in the value of the efficiency depending on the angular velocity of the ring gear and the gear ratio. For the first time, analytical expressions were obtained to determine the efficiency of the gear differential of a speed-changing device with a driving sun gear, driven carrier, or vice versa, more accurately. The resulting graphical dependences for efficiency visually allow to trace change of efficiency value depending on angular speed of a ring gear, as a control link, and the gear ratio. Results are recommended for introduction into design and engineering practice at development of designs of speed change devices through differential gears of drives of various equipment and in educational process of higher technical educational institutions in discipline of mechanical engineering. Areas of further research – improvement of speed change devices through gear differentials in the design, manufacture, operation and repair.

Estilos ABNT, Harvard, Vancouver, APA, etc.

42

Hao, Runsheng. "Application of S7-300 PLC and Single Axis Motion Controller in Manipulator Control System". Journal of Physics: Conference Series 2200, n.º 1 (1 de fevereiro de 2022): 012006. http://dx.doi.org/10.1088/1742-6596/2200/1/012006.

Texto completo da fonte

Resumo:

Abstract A set of flexible manufacturing production line training equipment in the college carries materials through a manipulator, which is controlled by S7-300 PLC. The FM353 module in the control system is damaged, and the device cannot be used. In order to repair the control system, this paper proposes a low cost solution. By choosing a single axis motion controller to replace the FM353 module function and S7-300 PLC with the control system/PLC control single axis motion controller can send high speed pulse output to the stepper driver, achieve the position and speed control of the stepper motor, and realize the control of a four degrees of freedom manipulator. Based on the design scheme, the control system of the manipulator is reformed. After modification, the system can run normally, which verifies the rationality and effectiveness of the design.

Estilos ABNT, Harvard, Vancouver, APA, etc.

43

Ghazali, Emna, Marie-Laure Dano, Augustin Gakwaya e Charles-Olivier Amyot. "Experimental and numerical studies of stepped-scarf circular repairs in composite sandwich panels". International Journal of Adhesion and Adhesives 82 (abril de 2018): 41–49. http://dx.doi.org/10.1016/j.ijadhadh.2017.12.008.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

44

Liu, Bin, Qing Han, Xiaoping Zhong e Zhixian Lu. "The impact damage and residual load capacity of composite stepped bonding repairs and joints". Composites Part B: Engineering 158 (fevereiro de 2019): 339–51. http://dx.doi.org/10.1016/j.compositesb.2018.09.096.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

45

Beylergil, Bertan, Alaattin Aktas e Yusuf Cunedioglu. "Buckling and compressive failure of stepped-lap joints repaired with composite patches". Journal of Composite Materials 46, n.º 26 (15 de fevereiro de 2012): 3213–30. http://dx.doi.org/10.1177/0021998312437001.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

46

Devasahayam, Augustine Joshua, Liam Patrick Kelly, John Bradley Williams, Craig Stephen Moore e Michelle Ploughman. "Fitness Shifts the Balance of BDNF and IL-6 from Inflammation to Repair among People with Progressive Multiple Sclerosis". Biomolecules 11, n.º 4 (26 de março de 2021): 504. http://dx.doi.org/10.3390/biom11040504.

Texto completo da fonte

Resumo:

Physical sedentarism is linked to elevated levels of circulating cytokines, whereas exercise upregulates growth-promoting proteins such as brain-derived neurotrophic factor (BDNF). The shift towards a ‘repair’ phenotype could protect against neurodegeneration, especially in diseases such as multiple sclerosis (MS). We investigated whether having higher fitness or participating in an acute bout of maximal exercise would shift the balance of BDNF and interleukin-6 (IL-6) in serum samples of people with progressive MS (n = 14), compared to matched controls (n = 8). Participants performed a maximal graded exercise test on a recumbent stepper, and blood samples were collected at rest and after the test. We assessed walking speed, fatigue, and maximal oxygen consumption (V·O2max). People with MS achieved about 50% lower V·O2max (p = 0.003) than controls. At rest, there were no differences in BDNF between MS and controls; however, IL-6 was significantly higher in MS. Higher V·O2max was associated with a shift in BDNF/IL-6 ratio from inflammation to repair (R = 0.7, p = 0.001) when considering both groups together. In the MS group, greater ability to upregulate BDNF was associated with faster walking speed and lower vitality. We present evidence that higher fitness indicates a shift in the balance of blood biomarkers towards a repair phenotype in progressive MS.

Estilos ABNT, Harvard, Vancouver, APA, etc.

47

Kozyr, V., A. Majstrenko e G. Dimchia. "Feeding level of repair piglets and subsequent productivity of sows in conditions of steppe zone". Visnyk agrarnoi nauky 94, n.º 12 (15 de dezembro de 2016): 33–37. http://dx.doi.org/10.31073/agrovisnyk201612-07.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

48

Jia Baohui, e Zhao Luchun. "Finite Element-based Parametric Investigations of the Stepped-lap Repairs to Laminated Cylindrical Shell with Stiffeners". International Journal of Advancements in Computing Technology 4, n.º 14 (31 de agosto de 2012): 83–91. http://dx.doi.org/10.4156/ijact.vol4.issue14.11.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

49

Lisachov, Artem P., Katerina V. Tishakova, Yakov A. Tsepilov e Pavel M. Borodin. "Male Meiotic Recombination in the Steppe Agama, Trapelus sanguinolentus (Agamidae, Iguania, Reptilia)". Cytogenetic and Genome Research 157, n.º 1-2 (2019): 107–14. http://dx.doi.org/10.1159/000496078.

Texto completo da fonte

Resumo:

Meiotic recombination rates and patterns of crossover distributions along the chromosomes vary considerably even between closely related species. The adaptive significance of these differences is still unclear due to the paucity of empirical data. Most data on recombination come from mammalian species, while other vertebrate clades are poorly explored. Using immunolocalization of the protein of the lateral element of the synaptonemal complex (SYCP3) and the mismatch-repair protein MLH1, which marks mature recombination nodules, we analyzed recombination rates and crossover distribution in meiotic prophase chromosomes of the steppe agama (Trapelus sanguinolentus, Agamidae, Acrodonta, Iguania) and compared them with data obtained for the genus Anolis (Dactyloidae, Pleurodonta, Iguania). We found that, despite a smaller genome size, the total SC length and the MLH1 focus number per cell are much higher in the agama than in the anoles. The distributions of the MLH1 foci in the agama are multimodal in larger chromosomes and bimodal in smaller chromosomes without a significant centromere effect, resembling the patterns known for birds. A possible relationship between karyotype remodeling and the evolution of recombination in Iguania is discussed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

50

Pakasi, Christian Jacob, Romels Lumintang, Irvan Rondonuwu e Charles Punuhsingon. "MODIFIKASI SISTEM ERETAN PADA EMCO COMPACT 5-PC CNC LATHE". Jurnal Poros Teknik Mesin UNSRAT 13, n.º 1 (1 de agosto de 2024): 25–37. http://dx.doi.org/10.35793/jptmu.v13i1.57190.

Texto completo da fonte

Resumo:

The EMCO Compact 5-PC CNC Lathe engine made in Austria in the laboratory majoring in Mechanical Engineering, Sam Ratulangi University has not been operating due to the use and maintenance of machines that have been lasted for years so that they are not maintained and cannot be operated anymore. In order to be operated again, the machine needs to be repaired and modified. The purpose of this study is the modification of the eretan system in the EMCO Compact 5-PC CNC Lathe by adding a belt transmission system and calibrateing the motor stepper using a computer, so that a more precise product can be produced. Modification of the EMCO Compact 5-Pc CNC Lathe eretan system has been successful. The Modification Process of EMCO Compact 5-Pc CNC Lathe carried out is the replacement of old components with new components and assembling the grade system components based on the CAD image that has been created. Then the machine is connected to a computer/laptop to calibrate and adjust the speed of the stepper motor on the X axis, Y axis, and X axis through the GRBL Controller Software so that the resulting movements are the same as those programmed. Keywords: Modification, CNC Lathe, CAD, Calibration, Stepper Motor, GRBL, Arduino Microcontroller

Estilos ABNT, Harvard, Vancouver, APA, etc.

Artigos de revistas sobre o tema "Stepped repair"

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos