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International Conference on Solid-Solid Phase Transformations in Inorganic materials 2015, PTM 2015

作者： Escobar, Julian D. Faria, Guilherme Wu, Leonardo Mei, Paulo R. Ramirez, Antonio J. Brazilian Nanotecnology National Laboratory P.O. Box 6192 Campinas-SP Brazil School of Mechanical Engineering State University of Campinas 200 Rua Mendeleyev Campinas-SP Brazil Dept. of Materials Science and Engineering Ohio State University 1248 Arthur E. Adams Drive ColumbusOH United States

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Optimal Path Planning and Resource Allocation for Active Target Localization

Optimal Path Planning and Resource Allocation for Active Tar...

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American Control Conference

作者： Charles Freundlich Philippos Mordohai Michael M. Zavlanos Dept. of Mechanical Engineering and Materials Science Duke University Durham NC 27708 USA Dept. of Computer Science Stevens Institute of Technology Hoboken NJ 07030 USA

ISBN: (纸本)9781479917730

This paper addresses optimal path planning and resource allocation for active multi-target localization. For each target, we solve a local Dynamic program (DP) that plans optimal trajectories in the joint state-space of robot positions and target location uncertainties, captured by a cumulative error covariance matrix. The transitions in the space of robot positions are governed by the robot dynamics, while the transitions in the space of target uncertainties are regulated by a Kalman filter (KF) that fuses new information about the target locations with the current beliefs. The fused target uncertainties enter the objective function of the local DP using the trace of the associated covariance matrix. Using the optimal sensing policies local to each target, we construct a global DP to determine how far along the single target optimal trajectories the sensor should travel before transitioning to the next target. The integrated system jointly optimizes the collective target localization uncertainty and the total distance traveled by the sensing agent. The proposed control scheme is more computationally efficient than methods that use only the sensor configuration to compute future uncertainty and more exact than methods that abstract away the filtered sensing uncertainty.

关键词： Robot sensing systems Uncertainty Covariance matrices Silicon Eigenvalues and eigenfunctions

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Microstructure analysis of synthesized iron substituted Ni44Fe6Mn32Al18 Heusler alloy

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AIP Conference Proceedings 2016年第1期1729卷

作者： Hamdan Akbar Notonegoro Deni Ferdian Yus Prasetyo Azwar Manaf 1PPS Materials Science Physics Dept. FMIPA Universitas Indonesia Depok Indonesia 2Mechanical Engineering Dept. FT-UNTIRTA Jl. Jend. Soedirman KM.3 Cilegon 42435 Indonesia 3Metallurgy and Materials Engineering Dept. Fakultas Teknik Universitas Indonesia Depok Indonesia

Chlorofluorocarbons (CFCs) which emitted to the atmosphere have been recognized to cause damage to the ozone layer. Alternative materials to replace the CFC’s role are those which have properties of the magneto caloric effect (MCE) like Heusler alloys. In this paper, we report results of synthesis studies of the magneto caloric materials based on Ni-Mn-Al which possesses the structure of Heusler alloy. Crystallographically, the alloy is a single phase system with a general formula of X2YZ which possesses the L21 (the Strukturberichte - SB) crystal structure. An iron substituted Ni44Fe6Mn32Al18 alloy was successfully casted by means of melting in a vacuum arc melting furnace. Series of microstructure as cast alloy which studied under SEM observation and EDAX analysis reveals that the cast sample consisted of at least 4 phases. These are the main phase of Ni-Mn-Al system with the additional minor phases of Al rich, Al-oxide and Al deficit main phases, respectively. Annealing process at 900 °C in oxygen free atmosphere for 48 hours have transformed dendritic structure into equaixed grain with fine particle scattered on the entire grain surfaces.

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A demonstration of improved constraints on primordial gravitational waves with delensing

arXiv

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arXiv 2020年

作者： Ade, P.A.R. Ahmed, Z. Amiri, M. Anderson, A.J. Austermann, J.E. Avva, J.S. Barkats, D. Thakur, R. Basu Beall, J.A. Bender, A.N. Benson, B.A. Bianchini, F. Bischoff, C.A. Bleem, L.E. Bock, J.J. Boenish, H. Bullock, E. Buza, V. Carlstrom, J.E. Chang, C.L. Cheshire, J.R. Chiang, H.C. Chou, T.-L. Citron, R. Connors, J. Moran, C. Corbett Cornelison, J. Crawford, T.M. Crites, A.T. Crumrine, M. Cukierman, A. de Haan, T. Dierickx, M. Dobbs, M.A. Duband, L. Everett, W. Fatigoni, S. Filippini, J.P. Fliescher, S. Gallicchio, J. George, E.M. Germaine, T.St. Goeckner-Wald, N. Goldfinger, D.C. Grayson, J. Gupta, N. Hall, G. Halpern, M. Halverson, N.W. Harrison, S. Henderson, S. Henning, J.W. Hildebrandt, S.R. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Huang, N. Hubmayr, J. Hui, H. Irwin, K.D. Kang, J. Karkare, K.S. Karpel, E. Kefeli, S. Kernasovskiy, S.A. Knox, L. Kovac, J.M. Kuo, C.L. Lau, K. Lee, A.T. Leitch, E.M. Li, D. Lowitz, A. Manzotti, A. McMahon, J.J. Megerian, K.G. Meyer, S.S. Millea, M. Mocanu, L.M. Moncelsi, L. Montgomery, J. Nadolski, A. Namikawa, T. Natoli, T. Netterfield, C.B. Nguyen, H.T. Nibarger, J.P. Noble, G. Novosad, V. O’Brient, R. Ogburn, R.W. Omori, Y. Padin, S. Palladino, S. Patil, S. Prouve, T. Pryke, C. Racine, B. Reichardt, C.L. Reintsema, C.D. Richter, S. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Schillaci, A. Schmitt, B.L. Schwarz, R. Sheehy, C.D. Sievers, C. Smecher, G. Soliman, A. Stark, A.A. Steinbach, B. Sudiwala, R.V. Teply, G.P. Thompson, K.L. Tolan, J.E. Tucker, C. Turner, A.D. Umiltà, C. Veach, T. Vieira, J.D. Vieregg, A.G. Wandui, A. Wang, G. Weber, A.C. Whitehorn, N. Wiebe, D.V. Willmert, J. Wong, C.L. Wu, W.L. Kimmy Yang, H. Yefremenko, V. Yoon, K.W. Young, E. Yu, C. Zeng, L. Zhang, C. Cardiff University CardiffCF10 3XQ United Kingdom SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Department of Physics and Astronomy University of British Columbia VancouverBCV6T 1Z1 Canada Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States Department of Physics University of Colorado BoulderCO80309 United States Department of Physics University of California BerkeleyCA94720 United States Harvard-Smithsonian Center for Astrophysics 60 Garden Street CambridgeMA02138 United States California Institute of Technology MS 249-17 1216 E. California Blvd. PasadenaCA91125 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Physics University of Melbourne ParkvilleVIC3010 Australia Department of Physics University of Cincinnati CincinnatiOH45221 United States Jet Propulsion Laboratory PasadenaCA91109 United States Department of Physics Harvard University CambridgeMA02138 United States Minnesota Institute for Astrophysics University of Minnesota MinneapolisMN55455 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada School of Mathematics Statistics & Computer Science University of KwaZulu-Natal

We present a constraint on the tensor-to-scalar ratio, r, derived from measurements of cosmic microwave background (CMB) polarization B-modes with "delensing," whereby the uncertainty on r contributed by the sample variance of the gravitational lensing B-modes is reduced by cross-correlating against a lensing B-mode template. This template is constructed by combining an estimate of the polarized CMB with a tracer of the projected large-scale structure. The large-scale-structure tracer used is a map of the cosmic infrared background derived from Planck satellite data, while the polarized CMB map comes from a combination of South Pole Telescope, Bicep/Keck, and Planck data. We expand the Bicep/Keck likelihood analysis framework to accept a lensing template and apply it to the Bicep/Keck data set collected through 2014 using the same parametric foreground modelling as in the previous analysis. From simulations, we find that the uncertainty on r is reduced by ∼ 10%, from σ(r)= 0.024 to 0.022, which can be compared with a ∼ 26% reduction obtained when using a perfect lensing template or if there were zero lensing B-modes. Applying the technique to the real data, the constraint on r is improved from r0.05 Copyright © 2020, The Authors. All rights reserved.

关键词： Cosmology

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Cyclic behavior of AZ31B Mg: Experiments and non-isothermal forming simulations

Cyclic behavior of AZ31B Mg: Experiments and non-isothermal ...

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作者： Lee, Chung An Lee, Myoung-Gyu Seo, Oh Suk Nguyen, Ngoc-Trung Kim, Ji Hoon Kim, Heon Young Department of Mechanical and Biomedical Engineering Kangwon National University 192-1 Hyoja2-dong Chuncheon Gangwon200-701 Korea Republic of Dept. of Materials Science and Engineering Korea University 145 Anam-Ro Seongbuk-Gu Seoul136-713 Korea Republic of School of Mechanical Engineering Pusan National University 2 Busandaehak-ro 63beon-gil Geumjeong-gu Busan609-735 Korea Republic of School of Mechanical Engineering Purdue University 585 Purdue Mall ME3011 West LafayetteIN47907 United States

Magnesium (Mg) alloys have unique room temperature mechanical properties such as yielding asymmetry, anisotropy, and unusual hardening response under strain path change. Mg alloy sheets often represent inferior formability at room temperature due to their limited active slip systems induced from specific microstructure and texture. This low formability is known to be mitigated as temperature increases, which is the result of active non-basal slip systems. Considering these unique properties, Mg alloy sheets has been often formed at 200 °C or higher. For optimizing the forming process using Mg alloy sheets, accurate constitutive models describing the unique behavior of the materials under non-proportional loading and non-isothermal temperature conditions are vital. In this paper, the mechanical behavior of AZ31B Mg alloy sheets under in-plane tension-compression (or compression-tension) cyclic loading was experimentally measured for various pre-strains and temperatures. Then, a practical hardening model modified from existing advanced hardening law was applied to calculate the stress-strain responses and formability in the cross shape die forming under non-isothermal condition. © 2015 Elsevier Ltd. All rights reserved.

关键词： Magnesium alloys

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The effect of mechanical deformation to the magnetic properties of stainless steel 304

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Journal of Physics: Conference Series 2016年第1期776卷

作者： N. Mubarok H. A. Notonegoro K. A. Zaini Thosin A. Manaf PPS Materials Science FMIPA-Universitas Indonesia Depok 16424 Indonesia Mechanical Engineering Dept. FT-Universitas Sultan Ageng Tirtayasa Cilegon 42435 Indonesia Pusat Penelitian Fisika LIPI Serpong Indonesia

A study of a non-magnetic 304 austenitic stainless steel alloy through mechanical deformation has been done. These specimens are pipe usually used to deliver gas which contains corrosive oil fields. The metallographic observation of a 20% deformation shows the increase in the value of the magnetization, as compensation for the formation of martensite phase as a result of a mechanical treatment. Martensitic phase formed due to a shift in the structure of the z-axis due to the effects of pressure and shear from the cold rolled. The existence of martensite phase and magnetic properties conducted through x-ray diffraction and permagraf investigation. An identified x-ray diffraction pattern shows the presence of a new peak between 10°-30° angle indicate the mechanical deformation in crystallite structure. Furthermore, at in 20% distortion, the value of magnetization is increased above 0.2 T in small coercivity value and caused decreased the ability of corrosion resistant.

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Deformation Zone Distribution of Continuous Extrusion Process

Manufacturing Technology

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Manufacturing Technology 2015年第2期15卷 11-12页

作者： Li, Yong Zhang, Yuxin Cui, Shiqiang Zhang, Ruizhu Zhong, Yi Dept. of Mechanical Engineering North China University of Water Resources and Electric Power ZhengzhouHenan450045 China School of Materials Science and Engineer Shanghai University Shanghai200444 China Kunming University of Science and Technology KunmingYunnan650093 China

Experiments and numerical simulations were conducted to analyze the deformation zone of aluminum cable in the conform extrusion process, and complex metal flow is observed by finite element. In this report, detailed studies were especially focused on the width of the extruding dies mouth and leakage gap which influenced on the metal deformation, then the stress and strain distribution and contact force distribution of arbitrary step were obtained with respect to different technical parameters among random steps. Furthermore, the relationship between the parameters of Δh and W/H was given, indicating that the intense internal Shear Band-IISB and leak gap affect the metal forming behavior, and enlarge obviously plastic deformation zone in a certain range. Consequently, it’s proper to be helpful for metal homogeneous deformation to reduce the entrance width of the extruding mold. © 2015. Published by Manufacturing Technology. All Rights Reserved.

关键词： Metals

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Investigating uncertainty in capability versus cost decision-making 17

Investigating uncertainty in capability versus cost decision...

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17th AIAA Non-Deterministic Approaches Conference 2015

作者： Forster, Edwin E. Beran, Philip S. Kolonay, Raymond M. Bae, Ha-Rok Wright-Patterson AFB 2210 Eighth St. OH45433 United States AFRL/RQVC Wright-Patterson AFBOH45433 United States Multidisciplinary Science and Technology Center AFRL/RQVC Wright-Patterson AFBOH45433 United States Dept. Mechanical and Materials Engineering Wright State University DaytonOH45435 United States

ISBN: (数字)9781624103476

ISBN: (纸本)9781624103476

Decision-making within a technology research organization requires knowledge of forecasting technological possibilities, technology delivery schedule, customer driven requirements, and past performance history. The decision maker’s intent is to maximize the impact of technology development to improve performance of existing applications or introduce new capabilities, within the constraints of resources available – funding, manpower, and time. The decision maker must often rely on deterministic valuations of future capabilities, which are sensitive to variability throughout the research and development process, and will impact costs for production, operation, and maintenance. Further, when considering technology development for an existing application, variability in that platform may alter the final results, potentially yielding much smaller improvements than originally projected. This effort outlines a methodology for developing a capability versus cost metric, application to a generic aerospace platform by selecting appropriate performance and cost parameters, and quantification of uncertainty within the methodology through variation of parameters by probabilistic distribution. Deterministic and non-deterministic results illustrate the intuitive result that there is a maximum efficiency for re-design, where increasing costs outpace increasing capability. © 2015 American Institute of Aeronautics and Astronautics Inc. All rights reserved.

关键词： Decision making

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Open-source, anthropomorphic, underactuated robot hands with a selectively lockable differential mechanism: Towards affordable prostheses

Open-source, anthropomorphic, underactuated robot hands with...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： G. P. Kontoudis M. V. Liarokapis A. G. Zisimatos C. I. Mavrogiannis K. J. Kyriakopoulos Control Systems Lab School of Mechanical Engineering National Technical University of Athens Athens Greece Dept. of Mech. Eng. and Materials Science Yale University New Haven CT USA Sibley School of Mechanical & Aerospace Engineering Cornell University Ithaca NY USA

In this paper we present an open-source design for the development of low-complexity, anthropomorphic, underactuated robot hands with a selectively lockable differential mechanism. The differential mechanism used is a variation of the whiffletree (or seesaw) mechanism, which introduces a set of locking buttons that can block the motion of each finger. The proposed design is unique since with a single motor and the proposed differential mechanism the user is able to control each finger independently and switch between different grasping postures in an intuitive manner. Anthropomorphism of robot structure and motion is achieved by employing in the design process an index of anthropomorphism. The proposed robot hands can be easily fabricated using low-cost, off-the-shelf materials and rapid prototyping techniques. The efficacy of the proposed design is validated through different experimental paradigms involving grasping of everyday life objects and execution of daily life activities. The proposed hands can be used as affordable prostheses, helping amputees regain their lost dexterity.

关键词： Robots Thumb Grasping Prosthetics Open source software Anthropomorphism Indexes

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The mechanical properties of austenite stainless steel 304 after structural deformation through cold work

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AIP Conference Proceedings 2016年第1期1746卷

作者： Naila Mubarok Hamdan Akbar Notonegoro Kemas Ahmad Zaini Thosin Azwar Manaf 1PPS Materials Science FMIPA-Universitas Indonesia Depok 16424 Indonesia 2Mechanical Engineering Dept. FT-Universitas Sultan Ageng TirtayasaCilegon 42435 Indonesia 3Pusat Penelitian Fisika LIPI Serpong Indonesia

The 304 stainless steel (SS) type is widely used in oil and gas operations due to its excellent corrosion resistance. However, the presence of the fine sand particles and H2S gas contained in crude oil could lead the erosion and abrasion in steel. In this study, cold rolled treatments were conducted to the 304 SS in order to increase the wear resistance of the steel. The cold work has resulted in thickness reduction to 20%, 40% and 60% of the original. Various microstructural characterizations were used to analyze the effect of deformation. The hardness characterization showed that the initial hardness value increased from 145 HVC to 395 HVC as the level of deformation increase. Further, the wear resistance increased with the deformation rate from 0% to 40% and subsequently decreased from 40% to 60% deformation rate. Microstructural characterization shows that the boundary change to coincide by 56 µm, 49 µm, 45 µm, and 43 µm width and the grain go to flatten and being folded like needles. The effect of deformation on the grain morphology and structure was also studied by optical metallography and X-Ray Diffraction. It is shown that the deformation by means of a cold rolled process has transformed the austenite structure into martensitic structure.

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