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1
Huang, Wen Kang, Xing Mei Huang, Hua Yang, Dong Sheng Liang e Ya Jun Zhou. "Innovative Design of a New Household Multi-Functional Shoe Cabinet". Advanced Materials Research 823 (ottobre 2013): 121–26. http://dx.doi.org/10.4028/www.scientific.net/amr.823.121.
Testo completoAbstract (sommario):
A new household multi-functional shoe cabinet was designed and prototyped. This shoe cabinet not only maintained the features of multi-function and intelligent control of the traditional one, but also made an innovation in its shortages. Through geometric space analysis and computation, selected rotary shoe rack for shoe storage for its space utilization rate is 1.6 times larger than the traditional one. A fully automatic shoe-cleaning device was designed and prototyped by using profiling mechanism, electronic timers and cam mechanism. Ozone disinfection and PTC dryer were used in shoes maintenance. The results in the performance test demonstrates that this shoe cabinet can accommodated 18 pairs of shoes in common use and clean and maintain shoes of size 34 ~ 45.
2
Gui, Wei, Zhi Chu Huang e Hong Chang. "The Design of the Rolling-Shoe Bearing Device Based on Rotary Cylinder". Advanced Materials Research 1037 (ottobre 2014): 95–98. http://dx.doi.org/10.4028/www.scientific.net/amr.1037.95.
Testo completoAbstract (sommario):
In this paper ,design a kind of rolling-shoe bearing device for supporting rotary cylinder, compare the characteristics of sliding shoe, roller, Rolling-Shoe Bearing, introduce the work principle of r Rolling-Shoe Bearing device, describe the overall structure of Rolling-Shoe Bearing device, the roller arrangement scheme, the design scheme of the raceway cover and structure of the main parts of the device. Research shows Rolling-Shoe Bearing device improves the stability, the reliability of the equipment operation, reduces the cost, and prolongs the service life of equipment.
3
Lin, Li Zong, Cheng Bing Cao, Hua Tao Cui e Sai Fei Wang. "Measurement Data Restoring Method of Shoe Last Based on Numerical Cutting Technology". Advanced Materials Research 472-475 (febbraio 2012): 1771–76. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.1771.
Testo completoAbstract (sommario):
From the perspective of Analytic Geometry, the spatial equation of milling cutter rotary surface is obtained. According to the measurement and machining of shoe last, a new measurement data restoring technology that is named Numerical Cutting is presented, and the Numerical Blade is defined. The working principle of Numerical Cutting Technology is introduced in detail, and it is used to restore the measurement data of shoe last. Then the discrete model of shoe last is gotten by shoe last CAD software. Finally, an application example of Numerical Cutting Technology is presented.
4
Mitka, Monika, Maciej Gawlik, Mariusz Bigaj e Wojciech Szymanski. "Continuous Rotary Extrusion (CRE) of Flat Sections from 6063 Alloy". Key Engineering Materials 641 (aprile 2015): 183–89. http://dx.doi.org/10.4028/www.scientific.net/kem.641.183.
Testo completoAbstract (sommario):
The study relates to a process of continuous rotary extrusion (CRE), also known under the name of a Conform Process. This method is used more and more extensively for the plastic working of metals and alloys. In CRE, the feedstock is fed into a profiled groove on the rotating extrusion wheel and is pressed by the pressing wheel. The friction of the extruded material against the rotating wheel generates a force that is pushing the material into the deformation chamber followed by extrusion through the die orifice. The extrusion by CRE was performed on an MC-260 device supplied by Meltech-Confex and installed at IMN - OML for processing of the 6063 aluminium alloy. The feedstock was composed of annealed rods. Two parameters were controlled during extrusion: the temperature of the shoe (element of the housing pressing the extruded material to the wheel) and the speed of the driving wheel. The 6063 alloy was extruded using the wheel speed of 2, 5, 10 and 15 rpm and the shoe temperature of 90°C and 105°C. The extruded flat sections were examined visually for continuity and quality of the resulting surface. In the feedstock rod and in the extruded flat sections (before and after heat treatment), the microstructure and grains were examined by light microscopy. Mechanical properties were also determined (static tensile test and hardness measurement). The study shows how the structure and the mechanical properties of the extruded flat sections are changing depending on the extrusion parameters applied. From the 6063 alloy rods extruded by CRE, flat sections of satisfactory quality were obtained. It was found that CRE yields the highest mechanical properties combined with the correct structure and high surface quality when the feedstock is extruded with the wheel rotational speed of 10 rpm and the shoe temperature of 105°C.
5
Chen, Lan, Lu Zhen Chen, Xiao Juan Yang e Ya Ping Yu. "Effects of Feed Shoe Wheel Speed on Tablet Weight Variability". Key Engineering Materials 492 (settembre 2011): 497–500. http://dx.doi.org/10.4028/www.scientific.net/kem.492.497.
Testo completoAbstract (sommario):
In many manufacturing industries, e.g. powder metallurgy, pharmaceuticals, ceramics and foodstuff, die compaction is widely applied. Although die filling has attracted increasing attention recently, very few published studies are available to predict powder flow rate from a moving feed shoe to dies. In this research, a feed shoe with three wheels of a high-speed rotary tablet press was studied. The powder discharge rates from the feed shoe and the tablet weight variability at different feeding wheel paddle speeds were investigated experimentally and numerically. The results of the two methods were in good agreement. According to the experimental results, the minimum deviation of tablet weight was obtained at the speed of 60 rpm. However, the wheel speed of 55 rpm was likely to be the better one on account of the calculations, which will be studied in the future experiments.
6
Lindenberg, Kelly M., e Christopher R. Carcia. "Muscle response times between shoe and no-shoe conditions following a weight-bearing rotary perturbation are similar in females". Journal of Electromyography and Kinesiology 19, n. 5 (ottobre 2009): e329-e333. http://dx.doi.org/10.1016/j.jelekin.2008.06.004.
Testo completo
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Wahyono, Wahyono, Eko Nugroho, Sulis Dri Handono e Eko Budiyanto. "Analisa uji ketahanan fatigue Aluminium scrap hasil remelting sepatu rem (brake shoe) terhadap variasi beban menggunakan tipe rotary bending". ARMATUR : Artikel Teknik Mesin & Manufaktur 1, n. 2 (18 settembre 2020): 96–107. http://dx.doi.org/10.24127/armatur.v1i2.340.
Testo completoAbstract (sommario):
Used brake shoes are a component of a two-wheeled vehicle that has a type of aluminum material. Therefore, we can do remelting aluminum from brake shoes that can no longer be used for advanced application use and utilization of brake shoe waste which still has a sale value. This study aims to determine the best value or the one that approximates the fatigue limit endurance value of each loading variation given to the specimen and to determine the characteristics of the fracture surface from the differences in given loading. The research method used for fatigue testing is by using a literature study and direct observation or observation. Before doing the fatigue testing, first, do the tensile test to get the yield strength value where this value is used for the loading that will be given to the fatigue test, the loading variations are given for the fatigue test are 40%, 50%, and 60 % of the yield strength value. From the results of fatigue testing at a load of 60% with the stress of 100.2 MPa and a given load of 3.81 kg, it can be seen that the value of material fracture at 27,421 cycles and in the timeframe 00:18:16. Then at 50% loading with the stress of 83.5 MPa and a given load of 3.18 g, it can be seen that the fracture value of the material in the 51,659 cycles in the fracture period is 00:34:35. Then in the next test with a load of 40% and given the stress of 66.8 MPa and a load of 2.5 kg, it is known that the fracture value of the material in the 106,930 cycles in the fracture period reaches 01:11:17. From the test data, it can be concluded that the ratio between cycle and time with voltage is inversely proportional, that is, the smaller the voltage the greater the cycle and time obtained, and vice versa, the greater the voltage, the smaller the cycle and time will be obtained.
Keywords: Used brake shoes, Aluminum, Remelting, load variation, fatigue test.
8
Vermeulen, G. D., J. J. Klooster, M. C. Sprong e B. R. Verwijs. "Soil Tare and Relative Soil Adherence after uprooting Sugar Beet by a Share Lifter, a Driven Rotary-shoe Lifter and a Grab Lifter". Biosystems Engineering 86, n. 2 (ottobre 2003): 167–78. http://dx.doi.org/10.1016/s1537-5110(03)00117-x.
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Gębura, Andrzej, e Tomasz Radoń. "Failures of avionic generators and contactors operated under harsh ambient conditions". Research Works of Air Force Institute of Technology 30, n. 1 (1 ottobre 2012): 153–76. http://dx.doi.org/10.2478/v10041-012-0010-4.
Testo completoAbstract (sommario):
The paper outlines failures of selected avionic electric power devices operated onboard of combat helicopters in Iraq and Afghanistan. While the authors were examining the electric power system of aircrafts in order to prolong their operation life they paid attention to numerous symptoms of wear demonstrated by some units of aircrafts. It was peculiar that such symptoms have never appeared during similar examinations of aircrafts operated in our country. By all accounts, the weird wear of components results from high intensity of flights and specific features of operating missions, but harsh climatic conditions seem to be the crucial factor. The authors believe that many of spotted failures experienced by electric power equipment may also happen to aircrafts operated in Poland but obviously, due to much lower intensity of operation and mild impact of environmental factors, such failures shall occur much later. The authors focused their attention on two groups of electric devices and associated destructive factors: 1. Air-cooled electric rotary machines. Fine-grained sand sucked together with air leads to very quick abrasion of protective paint coatings inside the machines. Not frequent but intense rainfalls are the reason for appearance of corrosion pits that lead to such effects as increase of pole shoe volumes. This, in turn, results in shearing of winding insulations with breakdowns (shorts) to ground and, as a final consequence, considerable drop of power demonstrated by an electric machine. 2. Contactors and electromagnets, which are allegedly tight. However, dust penetrates anyway via microfissures and disables operation of moving parts.
10
Wibowo, Dwi Basuki, e Ismoyo Haryanto. "KEGAGALAN FUNGSI PENGEREMAN BIS DAN TRUK AKIBAT RUSAKNYA KOMPONEN RAKITAN KAMPAS REM". ROTASI 17, n. 1 (1 gennaio 2015): 19. http://dx.doi.org/10.14710/rotasi.17.1.19-28.
Testo completoAbstract (sommario):
Federal Motor Vehicle Safety Standard (FMVSS) mengklasifikasikan kendaraan bis dan truk (trailer dan container) sebagai heavy duty vehicle dimana rem, kopling, dan ban adalah komponen-komponen yang harus diperiksa secara rutin karena berkaitan dengan keamanan dan umur pemakaiannya yang relatif pendek. Sebagai komponen utama material gesek kampas rem memang harus bagus dan harus lolos serangkaian test sebagaimana diatur dalam berbagai standard yaitu SNI 09-0143-1987, ASTM G0115-04, ASTM D3359-02. Tetapi menurut The American Public Transportation Association (APTA BTS-SS-RP-003-07), kinerja sistim pengereman bis dan truk tidak semata-mata ditentukan oleh kualitas material kampas rem saja tetapi juga oleh kondisi brake shoe dan prosedur pemasangan (rebuild) kampas pada brake shoe. Dari hasil survey banyak pengusaha transportasi bis di Indonesia yang mengabaikan prosedur rebuild kampas rem yang telah distandarkan oleh APTA BTS-SS-RP-003-07 tersebut. Akibatnya kampas rem cepat aus, rem terkunci, dan yang paling parah adalah rem blong (rem tidak berfungsi). Fokus utama penelitian ini adalah mengkaji kemungkinan kerusakan brake shoe assembly (komponen rakitan kampas rem) saat pengereman yang berpotensi menyebabkan terjadinya kegagalan fungsi pengereman pada bis/truk.
11
Russig, Christoph, Markus Bambach e Gerhard Hirt. "A New Tool Concept for Rotary Peen Forming with Defined Impact Positions". Key Engineering Materials 504-506 (febbraio 2012): 925–30. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.925.
Testo completoAbstract (sommario):
Rotary peen forming (RPF) has been developed as a new peen forming process in which the shot is held by a flexible connection and moved on a circular trajectory (see Fig. 1 below). The main advantage compared to a traditional shot peen forming (SPF) processes is that RPF does not need refeed of shot particles. Hence, RPF offers a compact machine design and a flexible use. The RPF process causes localized plastic deformation just as in traditional shot peen forming but involves tangential components which can create shear deformation in the plastic layer. These tangential components depend on the connection used for the setup. Compared to traditional shot peen forming, RPF shows different process characteristics in terms of coverage and the shape of indentations created on the surface of the workpiece. In this paper, a new tool concept for rotary peen forming is evaluated using experiments and numerical investigations of the process. The set-up uses a spring-attenuator system, which leads to more deterministic impact positions than previously used wire-based impactor concepts.
12
Suryo, Sumar Hadi, e Bambang Yunianto. "Pengaruh Kekuatan Bahan pada Track Shoe Excavator Menggunakan Pengujian Abrasive Wear dengan Metode Ogoshi Universal High Speed Testing". ROTASI 20, n. 1 (2 gennaio 2018): 5. http://dx.doi.org/10.14710/rotasi.20.1.5-15.
Testo completoAbstract (sommario):
Excavator adalah alat berat yang biasa digunakan dalam industri konstruksi, pertanian atau perhutanan. excavator memiliki fungsi utama untuk menggali dan memuat suatu material seperti tanah bebatuan dan lain - lain. Excavator memiliki 3 bagian, diantaranya ada attachment, base frame, dan undercarriage Salah satu bagian undercarriage excavator yang paling sering mengalami perawatan adalah track shoe. Track shoe merupakan crawler atau roda terluar pada excavator yang berfungsi sebagai penggerak pada excavator. Bagian ini selalu berkontak langsung pada tanah sehingga dapat menyebabkan keausan. Dalam penelitian ini akan dibahas mengenai perbandingan material track shoe sebelum di heat treatment dan setelah di quenching dengan media oli. Material yang digunakan adalah AISI 1526. Analisa yang dilakukan adalah uji mikorgrafi dimana untuk material non heat treatment terdapat fasa ferit dan pearlit, sedangkan untuk material yang di heat treatment berubah mejadi fasa martensit, uji kekerasan yang dilakukan pada matrial non heat treatment bernilai 41 HRC sedangkan untuk material heat treatment bernilai 45,3 HRC, uji keausan yang dilakukan pada material non heat treatment bernilai 1,28 mm3/day, lalu untuk material heat treatment bernilai 1,12 mm3/day dan uji korosi. Untuk material non heat treatment meiliki nilai laju keausan sebesar 0,51 mm/yr dan untuk material heat treatment 0,34 mm/yr. Pemeriksaan struktur mikro dari sampel dilakukan dengan mikroskop optik, uji kekerasan sampel dilakukan dengan menggunakan rockwel hardness tester, uji keausan dilakukan menggunakan metode Ogoshi High Speed Universal Wear, dan uji korosi menggunakan metode polarisasi potensiodinamik. Dari hasil analisa didapat nilai kekerasan berbanding terbalik dengan nilai keausan dan nilai korosi, semakin keras material nya, semakin kecil tingkat keausannya
13
Gottschalk, Markus, Markus Bambach e Gerhard Hirt. "Robot Controlled Rotary Peen Forming by Laser-Assisted Distance Control". Key Engineering Materials 651-653 (luglio 2015): 1084–89. http://dx.doi.org/10.4028/www.scientific.net/kem.651-653.1084.
Testo completoAbstract (sommario):
Surface curvature radii required for aircraft fuselage as well as structural components can be produced by peen forming processes. The innovative process idea of Rotary Peen Forming is a modification of the well-known Shot Peen Forming. Here, the impactors are flexibly connected to a rotating hub and thus moving on circular trajectories. As a consequence, there is no need to pressurize and recirculate the shots, as it is essential in Shot Peen Forming. Using a six axes robot, the rotating hub can be guided flexibly. The resulting machine design is more compact compared to traditional Shot Peen Forming.However, in Rotary Peen Forming not only principal stresses but also shear stresses are caused in the deformation zone which has a fundamental influence on the curvature. In order to generate defined curvatures on the workpiece, the capability to precisely adjust the intrusion depth of the impactors is essential.In this paper, a laser-assisted distance control for the Robot Controlled Rotary Peen Forming is introduced. By means of a point laser, the set-up allows for a distance control to adjust and keep a determined intrusion depth. This way, the machine design provides a mechanism to readjust the intrusion depth of the impactors while the desired curvature is formed during the process by the introduced plastic strains at the specimen’s surface. Using the distance control, the resulting curvature is two to four times bigger compared to experiments without a readjustment of the intrusion depth.
14
Russig, Christoph, Markus Bambach e Gerhard Hirt. "Experimental Investigations of Different Tool Concepts for Rotary Peen Forming". Key Engineering Materials 549 (aprile 2013): 53–60. http://dx.doi.org/10.4028/www.scientific.net/kem.549.53.
Testo completoAbstract (sommario):
Rotary Peen Forming (RPF) is a new peen forming process, comparable to Shot Peen Forming (SPF), in which the shot is held by a flexible connection and moved on a circular trajectory. Hence, RPF uses less machine components and therefore offers a compact machine design and a more flexible use than SPF. Just as conventional Shot Peen Forming the RPF process causes localized plastic deformation but involves tangential components which can create shear deformation in the plastic layer. In this paper, three different RPF tool concepts are compared and the applicability of Rotary Peen Forming for the production of slightly curved parts is analyzed. The first design offers a stochastic impact distribution, the second design leads to deterministic impacts. The third one is a further enhancement of the previous designs and combines the advantages of both. In contrast to previous tests a new, stiffer testing setup was used which offers good comparability of the tool concepts. Particularly the forming potential in terms of the realization of high curvatures and the surface quality are investigated. Depending on the tool concept the surface quality differs significantly, but generally RPF allows the forming of curvatures that are commonly used for aerospace structural parts.
15
Holzknecht, Eugen. "Economic blast cleaning with rotary barrel shot blast machines". Metal Finishing 105, n. 5 (maggio 2007): 37–40. http://dx.doi.org/10.1016/s0026-0576(07)80549-6.
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Marukovich, E. I., A. M. Branovitskiy, A. A. Kruglov, V. A. Dement’ev e N. P. Sadovskiy. "PRODUCTION OF ROTARY ENGINES’ PARTS FROM ALUMINUM ALLOYS USING LOST FOAM CASTING PROCESS". Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), n. 1 (6 aprile 2018): 16–21. http://dx.doi.org/10.21122/1683-6065-2018-1-16-21.
Testo completoAbstract (sommario):
The production technology of casting details for rotary engine from the aluminum alloy АК12М2 is developed. The bulk density of expanded polystyrene to ensure the best quality of the surface of castings has been experimentally established. The lost foam casting shop was organized in the experimental department of the Institute.
17
Oh, Kwang Keun, Yeon Wook Kim e Jae Hoon Kim. "High Cycle Fatigue Characteristics of Aluminum Alloy by Shot Peening". Advanced Materials Research 1110 (giugno 2015): 142–47. http://dx.doi.org/10.4028/www.scientific.net/amr.1110.142.
Testo completoAbstract (sommario):
An aluminum alloy is used in airplanes and aerospace to reduce the weight of structures. Recently, researchers have studied how to intensify the strength of aluminum alloys. Shot peening is one of method to reinforce strength by hitting the surface of materials to make residual stress. In this study, high cycle fatigue characteristics of aluminum alloy Al 7075-T6 and Al 2024-T4 were analyzed. Fatigue characteristics of before and after the shot peened materials were tested by cantilever-rotary bending fatigue test machine (YRB 200, Yamamoto). Also, fractographic analysis was performed by a Scanning Electron Microscopy (SEM). The results showed that the fatigue life of both shot peened materials increased more than others.
18
Wen, Ai Ling, Sheng Wu Wang, Rui Ming Ren e Xiu Xia Yan. "Effect of Combined Shot Peening on Fatigue Limit of TC4 which Have Different Microstructure". Applied Mechanics and Materials 55-57 (maggio 2011): 1138–41. http://dx.doi.org/10.4028/www.scientific.net/amm.55-57.1138.
Testo completoAbstract (sommario):
The rotary bending fatigue tests were to investigate the effect of the combined shot peening for surface nanocrystallization (CSPN) on the fatigue limit of titanium (TC4). CSPN formed nano-crystallization in surface layer of TC4, and may reduce and reducing the surface damage of TC4 by high energy shot peening. In the case of equiaxed microstructure, the fatigue limit of TC4 specimen treated by high-energy shot peening is increased by 13%, while the fatigue limit of TC4 specimen treated by the CSPN is increased by 34%. But in the case of lamellar microstructure, the fatigue limits of the specimens by either the surface treatment process both of the high energy shot peening and CSPN. The main reason of fatigue improvement change is due to that the effect of surface nanocrystallization and surface damage repairing by CSPN is changed between the different microstructure of TC4.
19
Hayashi, Chihiro, Masayoshi Akiyama e Tomio Yamakawa. "Advancements in Cone-type Rotary Piercing Technology". Journal of Manufacturing Science and Engineering 121, n. 3 (1 agosto 1999): 313–20. http://dx.doi.org/10.1115/1.2832683.
Testo completoAbstract (sommario):
A cone-type piercing mill was developed by the authors for materials with poor hot workability. This piercing mill is called “the super piercer” in Europe. It has a pair of cone-type main rolls supported at both ends with their roll axes inclined and crossed so as to enable piercing at high feed and cross angles. In order to ensure the best performance of the rotary piercing, disc rolls are adopted instead of plate guide shoes. The super piercer was put into practice at the small-diameter seamless tube plant operated in 1983. The recent progress in our research and development on the super piercer has resulted in the concept of “the new super piercer,” which allows expansion piercing. Namely, the development of the skewing technology for disc roll axes and its application to the cone-type piercing technology has realized remarkable increase in the expansion ratio. The new super piercer was adopted as the core technology of the new medium-diameter seamless tube plant operated in 1997. In this paper, studied in detail were the influences of the expansion ratio, feed and cross angles on the rotary forging effects, redundant shear deformations and power consumption.
20
Wibowo, Dwi Basuki. "Pengukuran Distribusi Beban Telapak Kaki Manusia Saat Berdiri Tegak Menggunakan Sensor FSR 402". ROTASI 20, n. 1 (2 gennaio 2018): 22. http://dx.doi.org/10.14710/rotasi.20.1.22-28.
Testo completoAbstract (sommario):
Manusia saat berdiri tegak ke dua telapak kaki bagian tumit menanggung beban 60% dari berat tubuh. Saat berjalan dan tumit menghentak di landasan, beban satu kaki bisa mencapai 70% dari berat tubuh. Beban yang besar di area tumit ini bisa menimbulkan nyeri hebat pada penderita calcanea spur (tumbuhnya taji di tulang tumit). Penelitian ini bertujuan mengetahui efektifitas penggunaan sensor FSR 402 buatan Interlink Electronics untuk mengukur distribusi beban di telapak kaki saat subyek berdiri tegak. Delapan sensor dipasang di sol sepatu dalam (shoe in-sole) disesuaikan dengan kecembungan kontur telapak kaki setiap subyek hasil pemindaian menggunakan 3D scanner. Hasil pengukuran menunjukkan beban rata-rata di area tumit pada tinggi hak sepatu 0 cm sebesar 27% dari berat tubuh atau lebih rendah 2% dibanding hasil penelitian sebelumnya. Menaikkan tinggi hak sepatu terbukti dapat menurunkan beban di area tumit dan menggesernya ke bagian tengah dan depan telapak kaki, juga sesuai dengan yang telah dilakukan oleh peneliti sebelumnya.
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Li, Xuejun, e Satyandra K. Gupta. "Geometric algorithms for automated design of rotary-platen multi-shot molds". Computer-Aided Design 36, n. 12 (ottobre 2004): 1171–87. http://dx.doi.org/10.1016/j.cad.2003.11.003.
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Kumar, Sudhir, P. Ratnakar, NV Murali Krishna Chakka, Sanjib Das, Anandamy Bagchi e Lavanya Anumula. "Do NiTi Instruments show Defects before Separation? Defects caused by Torsional Fatigue in Hand and Rotary Nickel-Titanium (NiTi) Instruments which Lead to Failure during Clinical Use". Journal of Contemporary Dental Practice 13, n. 6 (2012): 867–72. http://dx.doi.org/10.5005/jp-journals-10024-1243.
Testo completoAbstract (sommario):
ABSTRACT Aims Visual and microscopic evaluation of defects caused by torsional fatigue in hand and rotary nickel titanium (NiTi) instruments. Materials and methods Ninety-six NiTi greater taper instruments which were routinely used for root canal treatment only in anterior teeth were selected for the study. The files taken include ProTaper for hand use, ProTaper Rotary files and Endowave rotary files. After every use, the files were observed visually and microscopically (Stereomicroscope at 10×) to evaluate the defects caused by torsional fatigue. Scoring was given according to a new classification formulated which gives an indication of the severity of the defect or damage. Statistical analysis Data was statistically analyzed using KruskallWallis and Mann-Whitney U test. Results Number of files showing defects were more under stereomicroscope than visual examination. But, the difference in the evaluation methods was not statistically significant. The different types of defects observed were bent instrument, straightening/stretching of twist contour and partial reverse twisting. Endowave files showed maximum number of defects followed by ProTaper for hand use and least in ProTaper Rotary. Conclusion Visible defects due to torsional fatigue do occur in NiTi instruments after clinical use. Both visual and microscopic examinations were efficient in detecting defects caused due to torsional fatigue. This study emphasizes that all files should be observed for any visible defects before and after every instrumentation cycle to minimize the risk of instrument separation and failure of endodontic therapy. How to cite this article Chakka NVMK, Ratnakar P, Das S, Bagchi A, Kumar S, Anumula L. Do NiTi Instruments show Defects before Separation? Defects caused by Torsional Fatigue in Hand and Rotary Nickel-Titanium (NiTi) Instruments which Lead to Failure during Clinical Use. J Contemp Dent Pract 2012;13(6):867-872.
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Balaji, D. S., Thangasamy Jeyapoovan e C. Guhan. "Experimental Investigation and Process Optimization on Shot Peening of Aluminium Alloy (AA6061)". Applied Mechanics and Materials 852 (settembre 2016): 171–77. http://dx.doi.org/10.4028/www.scientific.net/amm.852.171.
Testo completoAbstract (sommario):
Shot peening operation is used to improve the mechanical properties of the materials. In this study new rotary peening machine is fabricated. The Hardness and Compressive stress were investigated with help of Vickers Hardness and UTM respectively. The peening parameters such as number of balls (75,100,125), diameter of ball (8,10,12mm), speed (200,300,400rpm) is considered and experimental setup is formulated by L9 orthogonal array. The above parameters are optimized by Taguchi method and MINITAB software. The microstructures of the sample are viewed with help of SEM images.
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Cecchini, Massimo, Francesca Piccioni, Serena Ferri, Gianluca Coltrinari, Leonardo Bianchini e Andrea Colantoni. "Preliminary Investigation on Systems for the Preventive Diagnosis of Faults on Agricultural Operating Machines". Sensors 21, n. 4 (23 febbraio 2021): 1547. http://dx.doi.org/10.3390/s21041547.
Testo completoAbstract (sommario):
This paper aims to investigate failures induced by vibrations on machines, focusing on agricultural ones. The research on literature has brought to light a considerable amount of data on the driven vehicles and not much on the operating machines, including the ones that we looked for. For this reason, it was decided to direct a survey with the people who work with agricultural machinery every day: operators, sub-contractors, and producers. They were asked about the most frequent breakage, particularly in relation to the rotary harrow, the topic of this work. The questionnaire results showed the types of failures the harrow is most vulnerable to, indicating the times of failure and reparation and the need to set up a potentially useful preventive maintenance supporting system on these machines. Part of the work was then focused on the proposition of a method to investigate bearing failures in the rotary harrow, considering that these have been analyzed in the technical literature and in the survey as the most at-risk components. The proposed method in this work serves as a beginning for the development of a future on board sent-shore-based maintenance system for continuous monitoring of the bearing.
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Wang, Ji, Shu-Xia Tang e Miroslav Krstic. "Adaptive output-feedback control of torsional vibration in off-shore rotary oil drilling systems". Automatica 111 (gennaio 2020): 108640. http://dx.doi.org/10.1016/j.automatica.2019.108640.
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Elemam, Ranya F., JA Capelas, Mário AP Vaz, Nuno Viriato, ML Pereira, A. Azevedo e John West. "Evaluating Transportation by Comparing Several uses of Rotary Endodontic Files". Journal of Contemporary Dental Practice 16, n. 12 (2015): 927–32. http://dx.doi.org/10.5005/jp-journals-10024-1783.
Testo completoAbstract (sommario):
ABSTRACT Aim To evaluate the frequent use of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) systems on shaping ability of root canal utilizing Solidworks (2014, Dassault Systèmes) software. Materials and methods Thirty-six root canals in clear resin blocks (Dentsply-Maillefer) were allocated into six experimental groups (n = 36). Six new sets of PTN instruments (Dentsply Maillefer, Ballaigues, Switzerland) were used six times to shape the resin blocks. A #15 K-file was inserted to the working length (WL), followed by ProGlider (PG) to create a glide path. Sequential use of PTN instrumentation in a crown-down technique was used to reach size (30/07) apically. Macroscopic photos of the blocks were taken before and after instrumentation, layered by Paint Shop Pro 9 from JascSoftware®, and then canal transportation was measured using Solidwork 2014. The data were analyzed by SPSS software version 22. Multivariate statistical analysis general linear model (GLM) was also applied. Bonferroni correction test was used in multiple comparisons and the statistical significance was set to 0.05. Results There was no difference in canal transportation resulted from utilizing PTN files after six multiple uses; in addition, the PTN files showed ability to maintain the original canal anatomy, especially in the apical level, where lowest total mean value of canal center displacement was seen (3 mm level) (0.019 ± 0.017). Conclusion ProTaper Next files can be used to prepare single and multiple canals in a single furcated tooth. Clinical significance ProTaper Next nickel-titanium (NiTi) file system is a safe instrument that respects the canal shape, allows practitioners to treat difficult cases with good results, and low risk of separation. How to cite this article Elemam RF, Capelas JA, Vaz MAP, Viriato N, Pereira ML, Azevedo A, West J. Evaluating Transportation by Comparing Several uses of Rotary Endodontic Files. J Contemp Dent Pract 2015;16(12):927-932.
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Lippmann, Thomas C., Edward B. Thornton e Timothy P. Stanton. "The Vertical Structure of Low-Frequency Motions in the Nearshore. Part I: Observations". Journal of Physical Oceanography 46, n. 12 (dicembre 2016): 3695–711. http://dx.doi.org/10.1175/jpo-d-16-0014.1.
Testo completoAbstract (sommario):
AbstractField observations of oscillating currents in the surfzone of a natural beach show significant vertical structure in energy, phase, and rotation at low frequencies around 0.005 Hz, where most of the energy is associated with vorticity motions. Energy levels in the cross-shore component of the flow seaward of the sandbar decay near the bottom. Shoreward of the bar crest, the flow decays nearly linearly over the water column. Conversely, a weaker alongshore component of the flow increases near the bottom seaward of the sandbar and is roughly depth-uniform inside the bar crest. Near this 0.005-Hz frequency band, the coherence between the uppermost and successive vertically separated sensors drops off quickly, with as much as a 70%–80% coherence drop over the water column (ranging from 2.5 to 4 m). The phase relative to the uppermost sensor shifts approximately linearly over depth, with as much as 50° phase lag at the bottom that can lag or lead the surface. Rotary coefficients also vary across the surfzone and are generally nonzero with rotational directions (cyclonic or anticyclonic) and orientation that depend on sensor position relative to the sandbar and alongshore current profile. The rotary coefficients are generally not uniform with depth and can change sign in the vertical. The observed behavior is qualitatively predicted by boundary layer theory (discussed in the companion paper by Lippmann and Bowen). The nonuniform vertical structure has implications to the interpretation of field data and horizontal nearshore mixing.
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Rosa, Joedy Maria Costa Santa, Fábio Roberto Dametto, Cicero Romão Gadê-Neto, Rejane Andrade de Carvalho, Diana Santana de Albuquerque, Cornelis Pameijer, Mário Tanomaru-Filho e Renato de Toledo Leonardo. "Influence of the rotary and/or oscillatory reciprocating systems in the morphological changes of narrow and curved molar root canals anatomy". Revista de Odontologia da UNESP 41, n. 5 (ottobre 2012): 353–59. http://dx.doi.org/10.1590/s1807-25772012000500010.
Testo completoAbstract (sommario):
OBJECTIVE: This study evaluated four mechanized Endodontic systems, ProTaper Universal, K3 Endo, Twisted file (rotary) and the oscillatory reciprocating system Endo - Eze TiLOS, in order to verify and measure alterations in original anatomy with deviations at cervical, medium and apical root canal thirds. MATERIAL AND METHOD: It was used MB root canals of 60 extract human lower molars, to produce a line of severe angles, according to the classification of Schneider. Samples were included in Ester vinyl resin, mounted in the Teflon Furnace, transversally sectioned at the cervical, middle and apical thirds, which were subsequently photographed using a digital camera Cyber Shot DSC-TX10,attached to an operating microscope 3101XY DFVasconcelos with 40× magnification in order to measure the anatomical transversal area of the root canal, using the software AutoCAD 2008, comparing pre and post-instrumentation. All samples assembled in the Furnace also were submitted to x-ray in a standardized way to enable the comparison of the angle of Schneider pre-and post-instrumentation. Once collected the data, they were compared statistically using the program BioEstat 5.0. RESULT: The analysis of the results showed that in the cervical third, rotary systems were more effective than Endo-Eze TiLOS System with statistically significant differences (p ≤ 0,05). Apical and middle third changes in anatomy were similar, but apically, the ProTaper system caused more deviations when comparing the angle of Schneider,and areas before and after instrumentation(p ≤ 0,05). CONCLUSION: It was concluded that all the systems caused alteration in the original anatomy of the root canal when parameters as angle of Schneider and areas before and after preparation were used.
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Junda, James, Erick Greene e David M. Bird. "Proper flight technique for using a small rotary-winged drone aircraft to safely, quickly, and accurately survey raptor nests". Journal of Unmanned Vehicle Systems 3, n. 4 (1 dicembre 2015): 222–36. http://dx.doi.org/10.1139/juvs-2015-0003.
Testo completoAbstract (sommario):
Small rotary-winged unmanned aerial vehicles or “drones” mounted with a small video camera were successful in surveying the nest contents of four species of raptor, including Osprey (Pandion haliaetus), Bald Eagle (Haliaeetus leucocephalus), Ferruginous Hawk (Buteo regalis), and Red-tailed Hawk (B. jamaicensis) in an accurate and safe manner when the proper flight technique was employed. A total of 110 surveys were completed in 2013 and 2014 with quality images of nest contents obtained in 106 or (96.4%) of flights. A successful and safe flight requires two personnel: the pilot who controls the aircraft and the spotter who monitors the behaviour of the adult birds defending the nest and keeps the pilot updated on all potentially dangerous interactions between aircraft and the birds. With the video camera recording, the aircraft is flown above the nest to a predetermined location that allows an unobscured camera shot of the nest. This technique can be readily adapted to a variety of habitat types and species. The accuracy of data obtained combined with the flexibility, low cost, and speed of this technique make it a useful technological alternative to the safety risks and obtrusiveness associated with traditional survey techniques.
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Carpenter, Chris. "Rotating Cement Heads Improve Results of Zonal Isolation in Colombia". Journal of Petroleum Technology 73, n. 05 (1 maggio 2021): 70–71. http://dx.doi.org/10.2118/0521-0070-jpt.
Testo completoAbstract (sommario):
This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 198970, “Casing Rotating Cement Heads: A Custom-Fit Solution To Improve Zonal Isolation Results In Colombia—A Field-Proven Case,” by Jose Vela, SPE, Henry Arias, and Edwin Sanchez, Ecopetrol, prepared for the 2020 SPE Latin American and Caribbean Petroleum Engineering Conference, held virtually 27–31 July. The paper has not been peer reviewed. In the current challenging drilling environment, effective annular zonal isolation is required for long-term integrity. Among proven cementing practices, casing rotation has been widely applied to liners but not as commonly to full casing strings. The complete paper describes the use of custom-fit rotating cement heads (RCH) to improve cementing results. Cementing Practices in Colombia The following methods of cementing, described in detail in the complete paper, are applied currently in Colombia: - Preflushes and spacers - Slurry design - Casing standoff - Borehole conditioning - Mud circulation and conditioning - Casing movement during the cement job - Monitor job parameters compared with design - Pressure testing and surface-equipment installation Most of these best cementing practices have been followed on a daily basis for all production and intermediate casing. Rotation practice has been widely applied to liners but not for casing strings. This observation led to the introduction of RCH, a technology that arose as the most- appropriate link to connect the top drive or rig prime mover with the casing so that rotation for a full string of casing could be achieved. RCH Use and Implementation Before the implementation of RCH, cement evaluation logs did not show the expected response. Evidence of fluid channeling and fluid contamination was very common, and fair casing to cement bonds was a concern, particularly in washed-out sections and very long cement columns. RCH provides a technical solution for the need to rotate the casing strings while maintaining best practices common to all cement jobs. Rotation has shown to be mandatory for intermediate and production casing to obtain a better log response by enhancing displacement fluid efficiency and mud removal. Well-design and cement objectives vary according to regional sedimentary basins around the country. In the Llanos Basin, the intermediate casing shoe integrity and the isolation of the T1 sand unit are primary objectives; the most-common wellbore problems are the presence of very washed-out sections in front of the E3 and E4 shale formations. The T1 sand unit is located between them and is prone to water or gas influx. Next, the production section is drilled with a lighter mud so that a high negative differential pressure is induced around the casing shoe once the shoe track is drilled. If shoe integrity is not suitable, an influx can be promoted when drilling the productive zone.
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Tsai, Ming-Yi, Yue-Feng Lin, Jihng-Kuo Ho e Jing-Guang Yang. "Ultrasonic-Assisted Innovative Polyurethane Tool to Polish Mold Steel". International Journal of Automation Technology 13, n. 2 (5 marzo 2019): 199–206. http://dx.doi.org/10.20965/ijat.2019.p0199.
Testo completoAbstract (sommario):
High-quality die and mold production is becoming increasingly important in modern mass production. Surface quality is one of the most frequent and stringent customer specifications for machined parts, of which the major consideration and indication of quality is their surface roughness. In this study, a novel ball-ended polishing tool made of polyurethane impregnated with micro cubic boron nitride (CBN) was developed. The polishing tool was mounted on a three-axis machining center; the rotary polishing action was achieved via ultrasonics. Polishing experiments were conducted on specimens of hardened Stavax stainless mold steel. Four types of polishing tools – containing 10 wt% of pure CBN particles and Al2O3coated CBN with two different degrees of hardness (Shore 25 and 45) – were fabricated; the results of the experiments were compared with those obtained using a traditional elastic-ball polishing tool. It was found that the surface quality achieved using the Al2O3coated CBN tool was superior to that with pure CBN particles because the hardness of the polishing tool increased with the increase in the surface roughness of the workpiece. In addition, ultrasonic-assisted polishing yielded a better surface finish.
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Sampathkumar, M., A. Sakthivel, P. Tharun Prasad, S. Vinothkumar e R. Vinothkumar. "Design and fabrication of electromagnetic braking system for four wheeler". South Asian Journal of Engineering and Technology 8, n. 1 (8 febbraio 2019): 1–3. http://dx.doi.org/10.26524/sajet190802.
Testo completoAbstract (sommario):
These brakes designed by controlling for equipment, automobiles and movers are suitable for AC&DC power supplies up to 12 v to 220 v and are suitable for wide range of drum sizes 10 to 380 mm dia these brakes are suitable with a rated torque ranging from 100kg-cm for the smallest brake up to 2000 kg-cm for a 380mm dia at 50% coil rating, the coil remains in circuit for a maximum 5 min out of every 10min. Since these brakes are closed position, the release of brake shoes is affected by energizing the electromagnetic coil which over comes the spring force and shoes are moved clear of drum by lever system so that the drum is free to rotate without any friction. When the power given to the electromagnetic coil the coil gets energized and in turns the plunger pulls down. The plunger in turn operates the arm of the brake and the brake opens. When specied brake drum both pin bush type and flexible geared type can be supplied along with the brakes.
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Houdijk, Han, Jos J. de Koning, Maarten F. Bobbert e Gert de Groot. "How Klapskate Hinge Position Affects Push-Off Mechanics in Speed Skating". Journal of Applied Biomechanics 18, n. 4 (novembre 2002): 292–305. http://dx.doi.org/10.1123/jab.18.4.292.
Testo completoAbstract (sommario):
In speed skating, the conventional skate has been replaced by the klapskate, in which the shoe can rotate around a hinge between shoe and blade. It has been hypothesized that the improved performance with klapskates vs. conventional skates can be attributed to the difference in the anterior/posterior position of the foot’s center of rotation relative to the ice. This study investigated the effect of the position of the foot’s center of rotation on push-off mechanics in speed skating. Eight elite speed skaters skated four 2000-m trials on instrumented klapskates at a fixed velocity. In each trial the hinge was placed at a different position between the 5th metatarso-phalangeal joint and the tip of the toes. 3-D kinematics and pushoff forces were measured to analyze push-off kinematics and kinetics. Shifting the hinge from the most posterior to the more anterior positions resulted in a delayed onset of foot rotation and longer duration of push-off. This delay coincided with an increase in angular displacement and peak angular velocity of the knee and hip joint, an increase in the flexing knee joint moment at the end of the push-off, and a reduction in work generated at the knee joint. Total work per stroke was similar for the various hinge positions. Besides the similar work per stroke, the observed effects are in accordance with the differences between klapskating and conventional skating. It was concluded that the position of the foot’s center of rotation affects the timing of foot rotation, and therefore the balanced pattern of segmental rotations. Although it could not be proven in this study, it was shown that this constraint could affect work per stroke and might explain the difference between klapskates and conventional skates.
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Cohen, R., M. G. Lipton, M. Q. Dai e B. Benhabib. "Conceptual Design of a Modular Robot". Journal of Mechanical Design 114, n. 1 (1 marzo 1992): 117–25. http://dx.doi.org/10.1115/1.2916904.
Testo completoAbstract (sommario):
In flexible automation approach to batch or job-shop production the main emphasis has always been on the re-programmability of the elements of a manufacturing system. The assumption that lies behind this philosophy is that “system flexibility” can be achieved through (mainly) software flexibility and limited hardware flexibility. Modular robots introduce a new dimension to flexible automation in terms of hardware flexibility, when compared to conventional industrial robots, in terms of yielding individual global optimal arm geometries for each of the tasks at hand. The objective of our ongoing research in the area of “mechanical design of modular robots” is to develop an inventory of basic modular units, which will allow a user to configure the most suitable robot geometry for a task (or a set of tasks) at hand. Standardization of these units and minimization of the size of the inventory constitute the two main goals of this research. In this paper some of our research results on the conceptual design of a modular robot are presented. The individual modular robot units that are presented include: one degree-of-freedom (dof) main joints (rotary and prismatic types), one dof end effector joints (Yaw, Pitch and Roll types), links and connectors.
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NANBU, Koichiro, Katsushi SARUKI e Satoru KONDO. "The Influence that Shot Peening and Micro Straight Notch Give to Rotary Bending Fatigue Strength of the High Si Hard-Drawn Wire". TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A 76, n. 762 (2010): 198–204. http://dx.doi.org/10.1299/kikaia.76.198.
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Han, Rui, Feng Ling Zhang, Shu Xia Guo, Peng Yin e Lei Wang. "Hub Eccentricity Measurement Based on Machine Vision". Advanced Materials Research 718-720 (luglio 2013): 409–14. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.409.
Testo completoAbstract (sommario):
In this investigation, a measurement system based on machine vision applied for auto-hubs eccentricity between the center hole and the pitch circle of bolt holes was proposed. The measurement system was integrated by a CCD camera with a telecentric lens, a diffuse bright-field back light illumination system, a rotating platform, a rotating encoder and an industrial computer. The camera was fixed at a suitable location from the rotation center, which ensured that one bolt hole and a part of the center hole could appear in its visual field. All bolt holes were shot when the auto-hub was rotating, while a rotary encoder recorded these angles. Then a global image of the auto-hub could be tiled by these pictures. An image-processing algorithm integrating morphology, circle fitting, affine transformation and edge extracting was used to measure the auto-hubs eccentricity. According to the measurement of a standard block that had 50um-eccentricity and was manufactured by WEDM-LS (Wire Cut Electrical Discharge Machining-Low Speed), the maximum deviation between measuring value and real value was less than 0.013mm, eccentricitys standard deviation was 0.0035mm and the standard deviation of eccentricitys direction angle was 2.37°. Meanwhile the experimental data of real auto-hubs gave an eccentricitys standard deviation less than 0.013mm and a direction angles standard deviation less than 2.1°.
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Бойко, П. І., Н. П. Коваленко e М. М. Опара. "ЕФЕКТИВНІ РІЗНОРОТАЦІЙНІ СІВОЗМІНИ У СУЧАСНОМУ ЗЕМЛЕРОБСТВІ". Вісник Полтавської державної аграрної академії, n. 3 (25 settembre 2014): 20–32. http://dx.doi.org/10.31210/visnyk2014.03.04.
Testo completoAbstract (sommario):
Розглянуто стратегію удосконалення та інноваціїструктури посівних площ і науково обґрунтованихсівозмін з урахуванням ґрунтово-кліматичних умовта спеціалізації господарств. Встановлено, що висо-копродуктивними й екологічно безпечними є різноро-таційні: короткоротаційні 3–4–5-пільні й довгоро-таційні 6–10-пільні зернові, зерно-просапні, зерно-паро-просапні, просапні, кормові сівозміни із широ-кими межами насичення зерновими, технічними йкормовими культурами. Виявлено, що ефект сівозмі-ни підвищується за збільшення різновидності сільсь-когосподарських культур і довжини ротації, що по-трібно враховувати в процесі розробки проектів зем-леустрою для забезпечення еколого-економічного об-ґрунтування сівозмін і впорядкування угідь, їхньогоскладу й змісту.
Strategy of improvement and innovation of structure of sowing areas and scientifically reasonable crop rotations is considered taking into account ground-climatic terms and specialization of economies. It is set that high-performance and environmentally sounds different term: shot term 3–4–5-fields and long term 6–10-fields grain, grain-growing, grain-par-growing, cultivated, forage crop rotations with the wide limits of satiation grain, technical and forage crops. It is discovered that the effect of crop rotation rises for the increase of variety of agricultural cultures and length of rotary press, that it is needed to take into account at development of projects of organization of the use of land for providing of eco-economical ground of crop rotations and organization of lands, their composition and maintenance.
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Liu, Su Yi, Yun Xu e Min Yin. "Analysis on Degree of Freedom of Leg Joint of Humanoid Robot for Fashion Show". Applied Mechanics and Materials 29-32 (agosto 2010): 1728–31. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.1728.
Testo completoAbstract (sommario):
According to the effect of the human joints and the motion characteristics of the models’ footstep, combining with the distribution condition of degree of freedom of biped robots lower extremity structure in and abroad, we determine the number of the degree of freedom of robots legs is 12. Hip joint which has the characteristics of left and right axial rotation at horizontal direction, anteroposterior axis rotation and vertical axial rotation has 3 degrees of freedom. Ankle joint has 2 degrees of freedom which can rotate in left, right, pre and post directions is similar with the human ankle. Knee joint has a degree of joint and it extend the legs. The key of the design of humanoid robots is the joints design. The design of degrees of freedom of the joint is very important for whether the robots can walk successfully.
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Костюк, І. М., Н. В. Сова, Б. М. Савченко, Р. Ш. Іскандаров e Б. П. Савчук. "ПОЛІМЕР-ПОЛІМЕРНИЙ КОМПОЗИТ ОТРИМАНИЙ ШЛЯХОМ ПЕРЕРОБКИ ВІДХОДІВ ПВХ ЛІНОЛЕУМУ". Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 122, n. 3 (4 ottobre 2018): 45–51. http://dx.doi.org/10.30857/1813-6796.2018.3.6.
Testo completoAbstract (sommario):
Development of technology for the processing of mixed waste of vinyl flooring by their joint milling and plasticization. The determination of the MFI was carried out according to ISO 1133: 1997 on a capillary viscometer with a constant pressure and temperature (190 ± 0.5) ° C and a weight of 2.16 kg. The thermostability and melting temperature were determined on the Hipro RM 200C plastograph. Mechanical properties were determined on a breaking machine according to ASTM D638. Hardness - using a Shore D durometer, hydrostatic weighing density on an analytical balance RADWAG AS-X2. Equipment for milling and plasticization of a mixture of PVC / PET waste was selected. Qualitative milling of mixed waste is achieved by using a low speed rotary knife grinder with rotor speed of 300 rpm. The properties of the reinforced PVC were obtained. The strength of this film compared with the classic recipe is lower but when by using such materials in the composition it is possible to obtain a material with high physical and mechanical properties and achieve maximum non-waste production which will also have a positive effect on the economy of the enterprise. The technology for joint processing of mixed vinyl flooring waste was developed for the first time. The features of reinforcing PVC matrix with fibers of a PET was obtained at the receipt of films from mixed vinyl flooring waste. The developed technology allows to provide non-waste production of vinyl flooring at enterprises.
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Nickerson, William C. "U.S. Naval Aviation: operational airframe experience with combined environmental and mechanical loading". Corrosion Reviews 33, n. 6 (1 novembre 2015): 285–91. http://dx.doi.org/10.1515/corrrev-2015-0067.
Testo completoAbstract (sommario):
AbstractAirframe structure is the core capability for all aviation operations, whether fixed or rotary wing, manned or unmanned, or ship-based or shore-based. Airframe materials are the underlying enabling technology for all air vehicle structures. Airframe maintainability is the primary availability and readiness driver for U.S. Naval Aviation. Traditionally, airframe structures are designed for immediate mechanical performance and loads-only structural response, and the degradation of properties over the life cycle and sustainment during operations are often an afterthought. Galvanic management and corrosion-resistant materials selection have never been done systematically as part of the structural analysis and lifing process. Additionally, the lack of true failure mechanism understanding of load path effects, crack initiation and growth behaviors, and nonuniform material response has often resulted in underdesign/overdesign, limits on new material insertion, costly life extension programs, and unexpected early in-service failures. Advances in structural and materials science for airframes offer significant opportunity for improvements in availability, readiness, reduced sustainment requirements, fatigue life enhancement, reduced weight and improved range, and enhanced design tools and standard practices. These science and technology advances would be realized in large part through the engineering and operational communities by facilitating mission profile-specific life prediction and operational requirement-tailored functionality, increasing operational readiness, reducing life-cycle costs, reducing logistics footprint, and lowering the maintenance burden on uniformed personnel. Durability can therefore be incorporated into the design and construction phase, where the largest return can be realized.
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Wang, Pengcheng, Zhongjie He, Keith R. Thompson e Jinyu Sheng. "Modulation of Near-Inertial Oscillations by Low-Frequency Current Variations on the Inner Scotian Shelf". Journal of Physical Oceanography 49, n. 2 (febbraio 2019): 329–52. http://dx.doi.org/10.1175/jpo-d-18-0047.1.
Testo completoAbstract (sommario):
AbstractNear-inertial oscillations (NIOs) on the inner Scotian shelf are studied using observations, a simple slab model, and two operational shelf circulation models. High-frequency radar and ADCP observations from December 2015 to February 2016 show that individual NIO events forced by time-varying wind stress typically lasted for three to four inertial periods. NIOs with speeds exceeding 0.25 m s−1 were observed in the offshore part of the study region, but their amplitudes decreased shoreward within ~40 km of the coast. The NIOs had spatial scales of ~80 and ~40 km in the alongshore and cross-shore directions, respectively. The NIO phases varied moving from west to east, consistent with the typical movement of winter storms across the study region. Evolving rotary spectral analysis reveals that the peak frequency fp of the NIOs varied with time by ~7% of the local inertial frequency. The variation in fp can be explained in part by local wind forcing as demonstrated by the slab model. The remaining variation in fp can be explained in part by variations in the background vorticity associated with changes in the strength and position of the Nova Scotia Current, an unstable baroclinic boundary current that runs along the coast to the southwest. Two operational shelf circulation models are used to examine the abovementioned features in the high-frequency-radar and ADCP observations. The models reproduce the spatial structure of the NIOs and, in a qualitative sense, the temporal variations of fp.
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Shanthini, J., P. Arunkumar, S. Karthik e N. Karthikeyan. "Interpretation of Gait Supervising Mechanism Using Sensor Integrated Makeshift and Analysing Pattern by K-Means Clustering Algorithm". Journal of Medical Imaging and Health Informatics 11, n. 10 (1 ottobre 2021): 2598–609. http://dx.doi.org/10.1166/jmihi.2021.3847.
Testo completoAbstract (sommario):
Human mobility or walking pattern(gait) is described as the interpreter movements of the rotatory body to achieve extensive range of locomotion. Gait analysis is foremost widely used technique for identifying abnormalities in the lower extremities and gait characteristics essentially support HAT (Head, Arm & Trunk). The act of walking is unconscious when there are no dysfunctions, but for ambulated the continuous monitoring is required. The existing clinical analysis method couldn’t achieve the daily walking routine within the confinement of a room.The proposed method focuses on developing an ambulatory system on daily routines by incorporating feasible techniques for achieving the gait pattern which is not confined to a room atmosphere where all possibilities of walking pattern can’t be reached.This system has expounded an ideology, to interpret the gait parameters using an insole type shoe integrated sensor system. Here, a wearable gait system which is incorporated with force resistive sensors, piezo sensors, inertial sensors and IR sensors are interfaced to the ESP 32. The corresponding sensors extract the data of kinematic angles, kinetics, foot pressure, step count and foot stride investigations.The system proved to be efficient in finding the phases and orientation of the individual by interpreting values from the device. Acquired data can be clustered together to find the abnormal and normal values by applying K-Means clustering algorithm, later the values are utilized in biomechanics for rectifying posture or movement related problems.The device will have several applications in sports, rehabilitation medicine and post-surgery treatment.
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Kumar, Nirnimesh, Falk Feddersen, Yusuke Uchiyama, James McWilliams e William O’Reilly. "Midshelf to Surfzone Coupled ROMS–SWAN Model Data Comparison of Waves, Currents, and Temperature: Diagnosis of Subtidal Forcings and Response". Journal of Physical Oceanography 45, n. 6 (giugno 2015): 1464–90. http://dx.doi.org/10.1175/jpo-d-14-0151.1.
Testo completoAbstract (sommario):
AbstractA coupled wave and circulation model that includes tide, wind, buoyancy, and wave processes is necessary to investigate tracer exchange in the shelf region. Here, a coupled Regional Ocean Model System (ROMS)–Simulating Waves Nearshore (SWAN) model, resolving midshelf to the surfzone region of the San Pedro Bay, California, is compared to observations from the 2006 Huntington Beach experiment. Waves are well modeled, and surfzone cross- and alongshore velocities are reasonably well modeled. Modeled and observed rotary velocity spectra compare well in subtidal and tidal bands, and temperature spectra compare well in the subtidal band. Observed and modeled mid- and inner-shelf subtidal velocity ellipses and temperature variability determined from the first vertical complex EOF (cEOF) mode have similar vertical structure. Although the modeled subtidal velocity vertical shear and stratification are weaker than observed, the ratio of stratification to shear is similar, suggesting model vertical mixing is consistent with observations. On fortnightly and longer time scales, the surface heat flux and advective heat flux divergence largely balance on the inner shelf and surfzone. The surfzone and inner-shelf alongshore currents separated by 220 m are unrelated. Both modeled and observed subtidal alongshelf current and temperature are cross-shelf coherent seaward of the surfzone. Wind forcing explains 50% of the observed and modeled inner-shelf alongshore current variability. The observed and modeled inner-shelf alongshelf nonuniformities in depth-averaged alongshore velocities are similar. Inferred, inner-shelf, wave-induced, cross-shore exchange is more important than on the U.S. East Coast. Overall, the coupled ROMS–SWAN model represents well the waves and subtidal circulation dynamics from the midshelf to the surfzone.
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Eron’ko, S. P., S. M. Gorbatyuk, M. Yu Tkachev e E. V. Oshovskaya. "DESIGN IMPROVEMENT AND OPERATION MODELING OF EAF GAS EXHAUST SYSTEM OF A FOUNDRY SHOP". Izvestiya. Ferrous Metallurgy 62, n. 1 (22 febbraio 2019): 34–41. http://dx.doi.org/10.17073/0368-0797-2019-1-34-41.
Testo completoAbstract (sommario):
As a result of a survey of gas exhaust systems of low-tonnage electric arc furnaces (from 3 to 10 tons) operated in the foundries of machine-building enterprises, the bottlenecks were identified, due to which a large amount of gas-dust emissions gets into the production rooms and pollutes the air in the working areas. First of all, it occurs due to the design schemes imperfection of the evacuation systems of gas and dust ejected from the furnace cavity through the outlet channel, the working window, gaps between its body and the roof, between edges of the holes in its upper part and the electrodes lowered through them. In particular, joint units of the rotary collection hoods with the gas exhaust pipelines in these systems do not provide proper sealing of movable joints. In this regard, the authors have proposed an improved design of rotation mechanism of the furnace collection hood, which involves the use of two sand gates. These gates eliminate the possibility of harmful emissions release between movably connected elements of the system into the environment. To begin designing of the industrial sample of a modernized mechanism, a method for calculating the energy-power parameters of its drive has been developed. A preliminary validation of the correctness of the taken technical decisions and of the obtained calculating dependencies was performed on the operating model of the investigated system manufactured on a 1:10 scale relative to the industrial sample. For the model research an instrumentation complex that included strain gauge transducer, AC amplifier, analogto-digital converter and computer was used. During this research the load acting on the model drive of the collection hood rotation mechanism when it was transferred from the working position to the parking one and back was fixed. At the same time, the load was measured for two cases: in the absence and in the presence of sand in the gates which ensure sealing of the movably joint elements of the investigated mechanical system. It was established that the portion of resistance forces arising in two sand gates during relative rotation of the moving element is 20 – 26 % of total load on the mechanism drive depending on angular velocity of the cantilever with collection hood. Similarly, this indicator calculated from obtained theoretical dependences was in the range of 17 – 23 % for the rotation mechanisms of collection hood of arc furnaces with a tonnage of 3 to 10 tons. Video filming of the smoke movement patterns, which flows from the furnace model through the existing gaps between its body and roof during the steelmaking process imitating, confirmed the reliability of the sand gates that provide complete sealing at the joint units of the moving parts of the collection hood rotation mechanism. Practical use of the proposed technical solution allows increasing of efficiency of evacuation of the harmful gas and dust emissions from the working zone of smelting furnaces used in the foundry.
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Smith, Lloyd, e James Sherwood. "Engineering our Favorite Pastime". Mechanical Engineering 132, n. 04 (1 aprile 2010): 44–48. http://dx.doi.org/10.1115/1.2010-apr-6.
Testo completoAbstract (sommario):
This article describes the equipment and technology advances in baseball and softball games. Research efforts are currently being pursued by the authors to develop a layer-by-layer finite element model of a baseball. While work on improved ball models is ongoing, a number of significant accomplishments have been made with current models. These include comparing bat performance, describing the plastic deformation (denting) observed in metal bats, and the failure modes observed with wood bats. To simulate the bat/ball impact at game-like speeds, a durability machine is used to fire balls at a bat at speeds up to 200 mph, at the rate of 10 per minute. After a ball is shot, it falls into a trough and is loaded back into the magazine, which holds up to 36 balls. The bat-support mechanism simulates the grip and flexibility of a batter and can be programmed to rotate the bat between hits to simulate the use of hollow bats or to remain “label up” as is needed for wood bats.
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Horan, Kate, James Coburn, Kieran Kourdache, Peter Day, Dan Harborne, Liam Brinkley, Henry Carnall et al. "Influence of Speed, Ground Surface and Shoeing Condition on Hoof Breakover Duration in Galloping Thoroughbred Racehorses". Animals 11, n. 9 (3 settembre 2021): 2588. http://dx.doi.org/10.3390/ani11092588.
Testo completoAbstract (sommario):
Understanding the effect of horseshoe–surface combinations on hoof kinematics at gallop is relevant for optimising performance and minimising injury in racehorse–jockey dyads. This intervention study assessed hoof breakover duration in Thoroughbred ex-racehorses from the British Racing School galloping on turf and artificial tracks in four shoeing conditions: aluminium, barefoot, aluminium–rubber composite (GluShu) and steel. Shoe–surface combinations were tested in a randomized order and horse–jockey pairings (n = 14) remained constant. High-speed video cameras (Sony DSC-RX100M5) filmed the hoof-ground interactions at 1000 frames per second. The time taken for a hoof marker wand fixed to the lateral hoof wall to rotate through an angle of 90 degrees during 384 breakover events was quantified using Tracker software. Data were collected for leading and non-leading forelimbs and hindlimbs, at gallop speeds ranging from 23–56 km h−1. Linear mixed-models assessed whether speed, surface, shoeing condition and any interaction between these parameters (fixed factors) significantly affected breakover duration. Day and horse–jockey pair were included as random factors and speed was included as a covariate. The significance threshold was set at p < 0.05. For all limbs, breakover times decreased as gallop speed increased (p < 0.0005), although a greater relative reduction in breakover duration for hindlimbs was apparent beyond approximately 45 km h−1. Breakover duration was longer on turf compared to the artificial surface (p ≤ 0.04). In the non-leading hindlimb only, breakover duration was affected by shoeing condition (p = 0.025) and an interaction between shoeing condition and speed (p = 0.023). This work demonstrates that speed, ground surface and shoeing condition are important factors influencing the galloping gait of the Thoroughbred racehorse.
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Kassai, Miklos. "Energy Performance Investigation of a Direct Expansion Ventilation Cooling System with a Heat Wheel". Energies 12, n. 22 (8 novembre 2019): 4267. http://dx.doi.org/10.3390/en12224267.
Testo completoAbstract (sommario):
Climate change is continuously bringing hotter summers and because of this fact, the use of air-conditioning systems is also extending in European countries. To reduce the energy demand and consumption of these systems, it is particularly significant to identify further technical solutions for direct cooling. In this research work, a field study is carried out on the cooling energy performance of an existing, operating ventilation system placed on the flat roof of a shopping center, located in the city of Eger in Hungary. The running system supplies cooled air to the back office and storage area of a shop and includes an air-to-air rotary heat wheel, a mixing box element, and a direct expansion cooling coil connected to a variable refrigerant volume outdoor unit. The objective of the study was to investigate the thermal behavior of each component separately, in order to make clear scientific conclusions from the point of view of energy consumption. Moreover, the carbon dioxide cross-contamination in the heat wheel was also analyzed, which is the major drawback of this type heat recovery unit. To achieve this, an electricity energy meter was installed in the outdoor unit and temperature, humidity, air velocity, and carbon dioxide sensors were placed in the inlet and outlet section of each element that has an effect on the cooling process. To provide continuous data recording and remote monitoring of air handling parameters and energy consumption of the system, a network monitor interface was developed by building management system-based software. The energy impact of the heat wheel resulted in a 624 kWh energy saving and 25.1% energy saving rate for the electric energy consumption of the outdoor unit during the whole cooling period, compared to the system without heat wheel operation. The scale of CO2 cross-contamination in the heat wheel was evaluated as an average value of 16.4%, considering the whole cooling season.
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Huyer, A., RL Smith, PJ Stabeno, JA Church e NJ White. "Currents off south-eastern Australia: results from the Australian coastal experiment". Marine and Freshwater Research 39, n. 3 (1988): 245. http://dx.doi.org/10.1071/mf9880245.
Testo completoAbstract (sommario):
The Australian Coastal Experiment was conducted off the east coast of New South Wales between September 1983 and March 1984. The experiment was conducted with arrays of current meters spanning the continental margin at three latitudes (37.5�, 34.5�, and 33.0�S.), additional shelf moorings at 29� and 42�S. coastal wind and sea-level measurements, monthly conductivity-temperature-depth probe/expendable bathythermograph (CTD/XBT) surveys, and two satellite-tracked buoys. Over the continental shelf and slope, the alongshore component of the current generally exceeded the onshore component, and the subtidal (<0.6 cpd, cycles per day) current variability greatly exceeded the mean flow. Part of the current variability was associated with two separate warm-core eddies that approached the coast, causing strong (>50 cm sec-1), persistent (>8 days), southward currents over the continental slope and outer shelf. Temperature and geostrophic velocity sections through the eddies, maps of ship's drift vectors and temperature contours at 250 m, and the satellite-tracked drifter trajectories showed that these eddies were similar in structure to those observed previously in the East Australian Current region. Both eddies migrated generally southward. Eddy currents over the shelf and slope were rare at Cape Howe (37.5�S.), more common near Sydney (34.5�S.), and frequent at Newcastle (33.0�S.), where strong northward currents were also observed. Near Sydney, the eddy currents over the slope turned clockwise with depth between 280 and 740 m, suggesting net downwelling there. Repeated CTD sections also indicated onshore transport and downwelling at shallower levels; presumably, upwelling occurred farther south where the eddy currents turned offshore. Periodic rotary currents over the continental slope near Sydney and Newcastle indicated the presence of small cyclonic eddies on the flank of a much larger anticyclonic eddy. Between early October and late January, no strong southward currents were observed over the continental margin near Sydney. Data from this 'eddy-free' period were analysed further to examine the structure and variability of the coastal currents. Much of this variability was correlated with fluctuations in coastal sea-level (at zero lag) and with the wind stress (at various lags). The coherence and phase relationships among current, wind-stress, and sea-level records at different latitudes (determined from spectral analysis and frequency-domain empirical orthogonal functions) were consistent with the equatorward propagation of coastal-trapped waves generated by winds in phase with those near Cape Howe. Time-domain empirical orthogonal functions show that the current fluctuations decayed with distance from shore and with depth, as expected of coastal-trapped waves.
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TRUSCOTT, TADD T., e ALEXANDRA H. TECHET. "Water entry of spinning spheres". Journal of Fluid Mechanics 625 (14 aprile 2009): 135–65. http://dx.doi.org/10.1017/s0022112008005533.
Testo completoAbstract (sommario):
The complex hydrodynamics of water entry by a spinning sphere are investigated experimentally for low Froude numbers. Standard billiard balls are shot down at the free surface with controlled spin around one horizontal axis. High-speed digital video sequences reveal unique hydrodynamic phenomena which vary with spin rate and impact velocity. As anticipated, the spinning motion induces a lift force on the sphere and thus causes significant curvature in the trajectory of the object along its descent, similar to a curveball pitch in baseball. However, the splash and cavity dynamics are highly altered for the spinning case compared to impact of a sphere without spin. As spin rate increases, the splash curtain and cavity form and collapse asymmetrically with a persistent wedge of fluid emerging across the centre of the cavity. The wedge is formed as the sphere drags fluid along the surface, due to the no-slip condition; the wedge crosses the cavity in the same time it takes the sphere to rotate one-half a revolution. The spin rate relaxation time plateaus to a constant for tangential velocities above half the translational velocity of the sphere. Non-dimensional time to pinch off scales with Froude number as does the depth of pinch-off; however, a clear mass ratio dependence is noted in the depth to pinch off data. A force model is used to evaluate the lift and drag forces on the sphere after impact; resulting forces follow similar trends to those found for spinning spheres in oncoming flow, but are altered as a result of the subsurface air cavity. Images of the cavity and splash evolution, as well as force data, are presented for a range of spin rates and impact speeds; the influence of sphere density and diameter are also considered.
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Kirillov, Sergei, Igor Dmitrenko, Søren Rysgaard, David Babb, Leif Toudal Pedersen, Jens Ehn, Jørgen Bendtsen e David Barber. "Storm-induced water dynamics and thermohaline structure at the tidewater Flade Isblink Glacier outlet to the Wandel Sea (NE Greenland)". Ocean Science 13, n. 6 (22 novembre 2017): 947–59. http://dx.doi.org/10.5194/os-13-947-2017.
Testo completoAbstract (sommario):
Abstract. In April 2015, an ice-tethered conductivity–temperature–depth (CTD) profiler and a down-looking acoustic Doppler current profiler (ADCP) were deployed from the landfast ice near the tidewater glacier terminus of the Flade Isblink Glacier in the Wandel Sea, NE Greenland. The 3-week time series showed that water dynamics and the thermohaline structure were modified considerably during a storm event on 22–24 April, when northerly winds exceeded 15 m s−1. The storm initiated downwelling-like water dynamics characterized by on-shore water transport in the surface (0–40 m) layer and compensating offshore flow at intermediate depths. After the storm, currents reversed in both layers, and the relaxation phase of downwelling lasted ∼ 4 days. Although current velocities did not exceed 5 cm s−1, the enhanced circulation during the storm caused cold turbid intrusions at 75–95 m depth, which are likely attributable to subglacial water from the Flade Isblink Ice Cap. It was also found that the semidiurnal periodicities in the temperature and salinity time series were associated with the lunar semidiurnal tidal flow. The vertical structure of tidal currents corresponded to the first baroclinic mode of the internal tide with a velocity minimum at ∼ 40 m. The tidal ellipses rotate in opposite directions above and below this depth and cause a divergence of tidal flow, which was observed to induce semidiurnal internal waves of about 3 m height at the front of the glacier terminus. Our findings provide evidence that shelf–basin interaction and tidal forcing can potentially modify coastal Wandel Sea waters even though they are isolated from the atmosphere by landfast sea ice almost year-round. The northerly storms over the continental slope cause an enhanced circulation facilitating a release of cold and turbid subglacial water to the shelf. The tidal flow may contribute to the removal of such water from the glacial terminus.