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Navy's CFC & Halon elimination program

NAVAL ENGINEERS JOURNAL 2000年第1期112卷 91-112页

作者： Toms, GS Breslin, DA Brunner, GP Thill, JC Gregory S. Toms RE:is the CFC & Halon Elimination Program Manager for the Naval Sea Systems Command (NAVSEA). He received a master of science degree in mechanical engineering from the University of Maryland and a B.S. degree in mechanical engineering from West Virginia University. From 1984 to 1997 he was employed at the Naval Surface Warfare Center Carderock Division Annapolis Detachment (formerly David Taylor Research Center) where he worked on the development of advanced centrifugal compressor air conditioning plants for shipboard applications. He received the Stratospheric Ozone Protection Award in 1998 from the U.S. Environmental Protection Agency in recognition of his exceptional leadership and technical achievements in eliminating ozone-depleting substances from Navy ships. He is licensed as a registered Professional Engineer in the state of Texas. David A. Breslin P.E.:is the Director of Technical Operations for the Naval Surface Warfare Center and is the Chairperson of the ASNE Committee on Environmental Engineering. He received a master of science in aerospace engineering from Virginia Tech in 1991 a master of engineering administration in industrial & systems engineering from Virginia Tech in 1991 and a bachelor of engineering in mechanical engineering from Stevens Institute of Technology in 1985. From 1993 to 1997 he was the program manager of the Naval Sea Systems Command's CFC & Halon Elimination Program. Because of his many efforts he received a Stratospheric Ozone Protection Award in 1995 from the U.S. Environmental Protection Agency in recognition of “exceptional contributions to global environmental protection”. Gregory P. Brunner:was employed by the Carderock Division of the Naval Surface Warfare Center and Naval Sea Systems Command (NAVSEA) from 1983 until 1997. From 1993 to 1997 he served as the R&D program manager for the NAVSEA CFC & Halon Elimination Program Office. Program efforts resulted in the development of new refrigerants for backfit into existing shipboard air-conditioning

The domestic production of the most powerful Ozone-Depleting Substances (ODSs) has permanently ceased and the abundant supplies of a number of inexpensive refrigerants, fire-fighting agents, and solvents, once taken for granted, are now a thing of the past. The Navy's original strategy of conserving ODSs, converting systems and processes where feasible, relying on strategic reserves where necessary, and developing "ozone-friendly" equip ment for new-design surface ships and submarines is succeeding. The purpose of this paper is to document the Navy's efforts to date relative to combating the threat to uninterrupted Fleet operations posed by the cessation of ODS production. Specifically, this paper addresses the Navy's shipboard conversion programs for air-conditioning and refrigeration (AC&R) systems, the development of next-generation AC&R systems, the selection of halon substitutes for new-construction fire-fighting systems, and the Navy's alternative to CFC-113 in the cleaning of critical oxygen systems.

关键词： conversion program Ozone depleting substances trichlorotrifluoroethane GRANTS fire fighting strategic reserves Solvents oxygen systems Submarine Halons

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Using an adjacent pulse repetition interval length as a scale for length measurement directly linked to a femtosecond optical frequency comb

Using an adjacent pulse repetition interval length as a scal...

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Frontiers in Optics, FIO 2012

作者： Wei, Dong Matsumoto, Hirokazu Global COE Program Mechanical Systems Innovation School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo 113-8656 Japan Department of Precision Engineering The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo 113-8656 Japan

The possibility of using an adjacent pulse repetition interval length (APRIL) as a scale, which is directly linked to a femtosecond optical frequency comb length standard tool, is investigated and demonstrated. ©... 详细信息

ISBN: (纸本)9781557529565

关键词： Natural frequencies

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The effect of stiffness and curvature on the haptic identification of surfaces

The effect of stiffness and curvature on the haptic identifi...

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World Haptics Conference

作者： V.S. Chib J.L. Patton K.M. Lynch F.A. Mussa-Ivaldi Biomedical Engineering Laboratory for Intelligent Mechanical Systems Northwestern University USA Biomedical Engineering Northwestern University USA Laboratory for Intelligent Mechanical Systems Mechanical Engineering Northwestern University Sensory Motor Performance Program Biomedical Engineering Department of Physiology Northwestern University

We perform experiments to investigate how humans acquire an internal representation of virtual objects through the execution of reaching movements across the object surface. Subjects were instructed to make reaching movements between points lying on the boundary of a planar virtual surface of varying stiffness. Results suggest two types of internal representation: force perturbations and object boundaries. In the first case, a rectilinear hand movement is enforced by opposing the interaction forces. In the second case, the trajectory is conformed to the object boundary so as to reduce interaction forces. While this dichotomy is evident for very rigid and very soft objects, the likelihood of identifying a surface boundary depended, in a smooth and monotonic way, on the average force experienced in the first movements. This continuum of interactive behaviors suggests that the nervous system uses a weighted combination of two control strategies, one generating a compensatory response, the other a compliant motion.

关键词： Haptic interfaces Biomedical engineering Laboratories Intelligent systems Intelligent sensors mechanical systems Humans mechanical engineering Physiology Nervous system

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Enhancing range of transport in Optical Tweezers assisted microfluidic chambers using automated stage motion

Enhancing range of transport in Optical Tweezers assisted mi...

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ASME 2013 International Design engineering Technical Conferences and Computers and Information in engineering Conference, IDETC/CIE 2013

作者： Chowdhury, Sagar Švec, Petr Thakur, Atul Wang, Chenlu Losert, Wolfgang Gupta, Satyandra K. Department of Mechanical Engineering University of Maryland College Park College Park MD 20742 United States Department of Mechanical Engineering Indian Institute of Technology Patna Patliputra Patna 800013 Denmark Department of Physics Biophysics Program University of Maryland College Park College Park MD 20742 United States Department of Mechanical Engineering Institute for Systems Research University of Maryland College Park College Park MD 20742 United States

ISBN: (纸本)9780791855843

In this paper, we present a planning approach for automated high-speed transport of cells over large distances inside an Optical Tweezers (OT) assisted microfluidic chamber. The transport is performed in three steps that combine the optical trap and motorized stage motions. This includes optical trapping and transporting the cells to form a desired cell-ensemble that is suitable for a long distance transport, automatically moving the motorized stage to transport the cell-ensemble over a large distance while avoiding static obstacles, and distributing the cells from the ensemble to the desired locations using OT. The speeds of optical traps and the motorized stage are determined by modeling the motion of the particle under the influence of optical trap. The desired cell-ensemble is automatically determined based on the geometry of the microfluidic chamber. We have developed a greedy heuristic method for optimal selection of the initial and the final location of the cell-ensemble to minimize the overall transport time while satisfying the constraints of the OT workspace. We have discussed the computational com- plexity of the developed method and compared it with exhaustive combinatorial search. The approach is particularly useful in applications where cells are needed to be rapidly distributed inside a microfluidic chamber. We show the capability of our planning approach using physical experiments. Copyright © 2013 by ASME.

关键词： Cells

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Folding angle and wing flexibility influence the flight performance of origami winged fruits

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Nonlinear Dynamics 2024年第13期112卷 10995-11011页

作者： Cai, Jing-Fang Hsu, Ya-Chun Yen, Yu-Chen Lee, Yun-Chung Peyton, Bernie Huang, Mei-Jiau Yu, Hon-Tsen Juang, Jia-Yang Department of Mechanical Engineering National Taiwan University Taipei106319 Taiwan Department of Life Science National Taiwan University Taipei106319 Taiwan Berkeley CA United States Program in Nanoengineering and Nanoscience Graduate School of Advanced Technology National Taiwan University Taipei106319 Taiwan Degree Program of Genome and Systems Biology National Taiwan University Taipei106319 Taiwan

Winged fruits possess a unique flight mechanism relying on simple geometric structures rather than neuromuscular control. This study proposes an innovative approach using origami techniques to create three-winged model fruits, serving as a proxy for understanding the flight dynamics of natural winged fruits. Paper is employed to simulate inherent wing flexibility, with the option to add plastic frames for rigidity. We comprehensively investigate the free fall motion of both rigid and flexible winged fruits through experimental and numerical analyses. Velocity–time curves reveal a three-stage descent pattern—acceleration, deceleration, and steady states. The overshoot phenomenon is attributed to rapid lift increase due to leading-edge vortices attaching stably to the wings. This insight sheds light on aerodynamics governing fruit flight. Compared with rigid wings, flexible wings exhibit two key properties—slower descent and higher self-orienting capability—that facilitate a more stable and longer-distance dispersal of seeds under crosswind conditions. Our study demonstrates the potential benefits of flexible wings in natural seed distribution. This study advances our understanding of winged fruit flight dynamics, utilizing origami as a powerful tool for biomimetic investigations. The findings have broad implications, from improving aerodynamic designs to developing efficient micro air vehicles and electronic microfliers, and understanding seed dispersal evolution. Graphical abstract: (Figure presented.). © The Author(s), under exclusive licence to Springer Nature B.V. 2024.

关键词： Fruits

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Wavelet neural network approach applied to biomechanics of swimming

Wavelet neural network approach applied to biomechanics of s...

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2013 13th UK Workshop on Computational Intelligence, UKCI 2013

作者： Puchalski, Weslly Mariani, Viviana Cocco Schauenburg, Felipe Fidelis Dos Santos Coelho, Leandro Industrial and Systems Engineering Graduate Program PPGEPS Pontifical Catholic University of Parana Curitiba Brazil Department of Mechanical Engineering PPGEM Pontifical Catholic University of Parana Federal University of Parana Curitiba Brazil Department of Electrical Engineering Pontifical Catholic University of Parana Federal University of Parana Curitiba Brazil

ISBN: (纸本)9781479915682

An artificial neural network (ANN) consists of a number of interconnecting artificial neurons and employs mathematical or computational models for information processing. ANNs are suitable for handling large amounts of dynamic, noisy and nonlinear data. On the other hand, the wavelet theory provides a multi-resolution approximation for discriminate functions. The combination of the wavelet transforms theory with the basic concept of ANNs leads to new mapping networks called wavelet neural networks (WNNs) or wavenets, which are proposed as an alternative to feedforward ANNs for approximating arbitrary nonlinear functions. Generalized from radial basis function ANNs, WNNs are in fact feed-forward neural networks with one hidden layer, radial wavelets as activation functions in the hidden nodes and a linear output layer. The contribution of this paper is to evaluate the WNNs to model a parathlete swimmer behavior. The parathlete swimmer swims the breaststroke style using biomechanics data generated by the software tool called SWUMSUIT, which was developed in Tokyo Technological Institute in Japan. The forecasted results clearly show that WNN has good prediction properties. The proposed WNN modeling approach can benefit disabled swimmers (parathletes) to gain competitive advantage by studying the biomechanics involved in the sport and considering the help of simulations systems. © 2013 IEEE.

关键词： Biomechanics

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Motion Detection Method of Electrostatic MEMS Resonators Operating in Aqueous Media 6

Motion Detection Method of Electrostatic MEMS Resonators Ope...

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6th International Youth Conference on Radio Electronics, Electrical and Power engineering, REEPE 2024

作者： Hemid, Mohamed Alattar, Basil Ghommem, Mehdi Ahmed, Alaaeldin Abdel-Rahman, Eihab Sabouni, Rana Mechatronics Graduate Program American University of Sharjah Sharjah United Arab Emirates American University of Sharjah Mechanical Engineering Department Sharjah United Arab Emirates Systems Design Engineering University of Waterloo Ontario Canada American University of Sharjah Chemical Engineering Department Sharjah United Arab Emirates

ISBN: (纸本)9798350382891

This paper introduces an experimental method to detect the motion of an electrostatic Micro-Electro-mechanical systems (MEMS) resonator in aqueous media. The resonator comprises a micro cantilever beam subject to electrostatic actuation through a side electrode. A Finite Element Method (FEM) model of the resonator is developed to determine the in-plane mode shapes and their natural frequencies in order to facilitate the experimental study. The motion of the resonator lead to variations in its capacitance and induce a current. The developed experiments demonstrate that motion-induced current can be measured and analyzed to detect the motion of the resonator's higher-order modes and can be used in chemical sensing. © 2024 IEEE.

关键词： Electrostatics

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Modeling of a 2-DOF Piezoelectric Micromanipulator at High Frequency Rates through Nonlinear Black-box System Identification

Modeling of a 2-DOF Piezoelectric Micromanipulator at High F...

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2018 Annual American Control Conference, ACC 2018

作者： Ayala, Helon Vicente Hultmann Rakotondrahe, Micky Coelho, Leandro Dos Santos Pontifical Catholic University of Rio de Janeiro Department of Mechanical Engineering Brazil Industrial and Systems Engineering Graduate Program Pontifical Catholic University of Paraná Brazil FEMTO-ST Institute Université Bourgogne Franche-Comté CNRS Besançon France Department of Electrical Engineering Federal University of Paraná Brazil

ISBN: (纸本)9781538654286

In the present paper we proceed the data-driven modeling of a two degrees of freedom (2-DOF) piezoelectric micromanipulator through models with the Nonlinear AutoRegressive with eXogenous inputs (NARX) structure and real acquired data. We show the results when the system is excited at high frequencies, aiming towards rapid and precise micropositioning. The order of NARX the models are increased until they satisfy the statistical tests based on higher-order correlations and the multiple correlation coefficients, which are close to unity for both measured outputs. The results herein presented encourage the use of data-driven methods for modeling piezoelectric micromanipulators. © 2018 AACC.

关键词： Data models Mathematical model Micromanipulators Analytical models Actuators"

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Hardware-based parallel firefly algorithm for embedded applications

Hardware-based parallel firefly algorithm for embedded appli...

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2013 NASA/ESA Conference on Adaptive Hardware and systems, AHS 2013

作者： Muñoz, Daniel M. Llanos, Carlos H. Dos Santos Coelho, Leandro Ayala-Rincón, Mauricio Electronics Engineering Graduate Program Faculty of Gama University of Brasilia Brasilia DF Brazil Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia DF Brazil Industrial and Systems Engineering Graduate Program LAS/PPGEPS Pontifical Catholic University of Parana Curitiba Parana Brazil Departments of Computer Science and Mathematics University of Brasilia Brasilia DF Brazil

ISBN: (纸本)9781467363839

The firefly algorithm (FA) is a new population-based metaheuristic bioinspired on the behavior of the flashing characteristics of fireflies. As a population-based algorithm, the FA suffers from large execution times specifically for embedded optimization problems with computational limitations. For reducing execution times we propose a hardware parallel architecture of the FA algorithm that facilitates the implementation in Field programmable Gate Arrays (FPGAs). In addition, this work proposes the application of the opposition-based learning (OBL) approach to the FA algorithm. The respective hardware implementation (HPOFA) was mapped into a Virtex5 FPGA device and numerical experiments using four well-known benchmark problems demonstrate that the opposition-based approach allows the FA algorithm to improve its functionality, preserving the swarm diversity and avoiding the premature convergence problem. Synthesis results point out that the HPOFA architecture is effectively mapped in hardware and is suitable for embedded applications. © 2013 IEEE.

关键词： Parallel architectures

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Characteristic study on the optimization of micro pin-fin heat sink with staggered arrangement

Characteristic study on the optimization of micro pin-fin he...

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作者： John, T.J. Mathew, B. Hegab, H. College of Engineering and Science Louisiana Tech University Ruston LA 71272 United States Micro and Nano Systems Track College of Engineering and Science LA Tech. Ruston LA 71272 United States Mechanical Engineering Program College of Engineering and Science LA Tech. Ruston LA 71272 United States

ISBN: (纸本)9781600867453

The effect of the Pin-fin shapes on the overall performance of the micro Pin-fin heat sink with staggered arrangement is studied in this paper. Six different shapes of micro Pin-fins, square, rectangle, circle, rhombus, triangle and ellipse are subjected to study in this paper. The optimization processes are carried out using computer simulations performed using COVENTORWARE™. The study is carried out over a range of Reynolds number ranging from 50 to 500 and a figure of merit term (FOM) consisting of both the thermal resistance and the pumping power is developed for the overall performance evaluation of different models. A weighted average scheme is used for developing the FOM term. The results of the study revealed that at low values of Reynolds numbers (Re200) rectangle showed the best performance. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Reynolds number

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