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38th IMAC, A Conference and Exposition on Structural Dynamics, 2020

作者： Witteveen, Wolfgang Thomas, Lauss Stefan, Oberpeilsteiner Study Program "Mechanical Engineering" University of Applied Sciences Upper Austria Wels Austria

ISBN: (纸本)9783030476250

FreeDyn (***) is a free multibody simulation (MBS) package consisting of a graphical user interface (GUI) and a C++ solver in which a modified version of the HHT time integration method is implemented. In order to underline the solvers efficiency with respect to CPU time, comparative simulations of FreeDyn and a commercial software product are presented in this paper. The main modelling elements of FreeDyn are rigid and flexible bodies, constraints, forces and measures (angle, position, velocity …). The FreeDyn standard force elements can be specified by user defined expressions. However, if a more advanced force is required, the user can link a user written subroutine (DLL) to FreeDyn. FreeDyn can be used as standalone software, which is controlled via the mentioned GUI. Alternatively, FreeDyn can be linked via a C-Interface as a dynamic link library (DLL) to other software like MATLAB, Scilab or self-written codes. The C-interface provides control functions for time integration and access to model data, which are normally hidden (e.g. mass matrix, constraint forces, Jacobi matrices etc.). Beside industrial applications, FreeDyn can be used in education and research. In Education: Beside the classical teaching elements like the creation and simulation of MBS models, it is furthermore possible, to look deeper inside the structure of the equations. This can be easily done by the use of the access routines of the C-Interface. In Research: FreeDyn enables quick implementations of particular research ideas in the context of MBS. The integration of those ideas can be realized with a user written subroutine and/or alternatively, by the use of the C-Interface. A researcher can focus on the research topic, while FreeDyn handles the MBS model. Moreover, due to the availability of very specific information, the C-Interface of FreeDyn is suitable for extraordinary optimization problems, which is underlined by an example and several literature citations. The paper co

关键词： Dynamics

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Improvement of corrosion resistance and heat dissipation of Mg-6%Al-4%Ca alloy by the addition of Mn, Mm, and the surface treatment

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Keikinzoku/Journal of Japan Institute of Light Metals 2023年第12期73卷 646-650页

作者： Ito, Mizuki Kondo, Natsuki Kirimoto, Yuichi Tsukeda, Tadayoshi Aida, Tetsuo Tabata, Hironobu Kurihara, Hideki Suzuki, Mayumi Program of Materials Science and Engineering Studies in Science and Engineering Graduate School of Science and Engineering University of Toyama 3190 Gofuku Toyama-shi Toyama930-8555 Japan School of Sustainable Design Materials and Engineering University of Toyama Toyama Toyama-shi Japan Department of Nano and Functional Material Science Graduate School of Science and Engineering for Education University of Toyama Toyama Toyama-shi Japan Faculty of Sustainable Design Academic Assembly University of Toyama Toyama Toyama-shi Japan CHUETSU METAL WORKS CO LTD.. Nakaniikawa-gun Toyama Japan Saitama Industrial Technology Center Kawaguchi-shi Saitama Japan Department of Mechanical Systems Engineering Faculty of Engineering Toyama Prefectural University Toyama Imizu-shi Japan

With the recent digitization, electronic equipment housings are required to be thin-walled and have rigidity, heat dissipation, corrosion resistance, and electromagnetic shielding properties. Magnesium alloys are promising materials that satisfy these requirements. Mg-Al alloys have good castability and high strength, but their thermal conductivity decreases. In general, adding alloying elements to magnesium decreases thermal conductivity the effect of aluminum addition is significant. It was found that adding calcium to Mg-Al alloys to form Mg-Al-Ca (AX) alloys results in higher thermal conductivity than that of Mg-Al alloys. However, AX alloys have poor corrosion resistance and require post-treatment such as surface treatment. In this study, AX64, which has high thermal conductivity among the AX series alloys, was used as the basic composition, and corrosion resistance was improved by adding manganese and misch metal, and an attempt was made to improve corrosion resistance and emissivity through surface treatment. The change in thermal conductivity by heat treatment was also investigated. Experimental results showed that the addition of manganese and misch metal improved corrosion resistance and thermal conductivity. Plasma anodization also improved corrosion resistance and emissivity. Heat treatment of these alloys at 400°C improved the thermal conductivity with longer holding time. © 2023 The Japan Institute of Light Metals.

关键词： Corrosion resistance

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Flexible multibody dynamics: Which terms of the equations of motion have to be considered for which problem? 38th

Flexible multibody dynamics: Which terms of the equations of...

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38th IMAC, A Conference and Exposition on Structural Dynamics, 2020

作者： Witteveen, Wolfgang Pichler, Florian Study Program "Mechanical Engineering" University of Applied Sciences Upper Austria Wels Austria

ISBN: (纸本)9783030476250

Scientists often face the task to carry out a "proof of concept" of a research idea. If this is related to multibody simulation of flexible bodies, it is sometimes necessary to implement a simple and problem-oriented multibody simulation code in programs like Matlab or Scilab. The question then arises, which terms of the equation of motion have to be considered when the flexible body is modelled along the Floating Frame of Reference Formulation. The consideration of all effects leads to very complex expressions and also require costly FE preprocessing. A remarkably simplified version can be obtained, by a strict application of the small deformation assumption to the level of the kinetic energy. But what is the truth in the context of a certain problem? Clear rules are provided, so that a researcher can decide for a particular mechanical system, which terms are required and which ones can be neglected. This work reviews a paper that has been recently published by the authors with respect to this question. © The Society for Experimental Mechanics, Inc 2021.

关键词： Equations of motion

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Financial Analysis of Cooling Systems for Environmental Conditioned Strawberry Cultivation in Semi-Closed Greenhouses in Chiang Mai, Thailand

Financial Analysis of Cooling Systems for Environmental Cond...

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Energy and Sustainable Development

作者： Chayanan Thanthong Napassawan Wongmongkol Chatchawan Chaichana Suwimon Wicharuck Department of Mechanical Engineering Graduate master's degree Program in Energy Engineering Faculty of Engineering Chiang Mai University Chiang Mai Thailand Department of Mechanical Engineering Faculty of Engineering Chiang Mai University Chiang Mai Thailand Energy Technology for Environment Research Center Faculty of Engineering Chiang Mai University Chiang Mai Thailand

ISBN: (数字)9798331517076

ISBN: (纸本)9798331517083

Strawberry production is an important crop in the northern region of Thailand that is only available in winter. Theoretically, strawberries can be grown in plant factories that can control the climate conditions strawberries need. Generally, the cooling load from lighting accounts for almost 80% of the total heat load in the plant factory. To reduce the cost of using light energy and the heat load in plant factories, this study was conducted on cultivation methods in semi-closed greenhouses that utilize natural light during the day. Coolness is generated by solar energy during the day and stored in cooling energy storage that stored coolness is used during the night. The total cooling load for year-round strawberry cultivation in the greenhouse was about 814 GJ, consisting of the stages of strawberry floral initiation, flowering, and fruiting at 17%, 17%, and 66%, respectively. In addition, the payback period is around 14.16 - 16.29 years.

关键词： Heating systems Costs Water storage Cooling Net zero Greenhouses Solar energy Flowering plants Machinery Meteorology

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Photocatalytic bio-inspired PDA-RGO/g-C3N4 nanocomposite incorporated PES membrane for removal of environmental antibiotic pollutants

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Journal of Chemical Technology and Biotechnology 2024年第6期99卷 1401-1413页

作者： Govardhanan, B. GokulaKrishnan, S.A. Arthanareeswaran, G. Ashok, M. Chen, Yong-Song Taweepreda, W. Membrane Research Laboratory Department of Chemical Engineering National Institute of Technology Tiruchirappalli Tiruchirappalli India New Generation Materials lab Department of Physics National Institute of Technology Tiruchirappalli Tiruchirappalli India Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-tech Innovations National Chung Cheng University Chiayi County Taiwan Polymer Science Program Division of Physical Science Faculty of Science Prince of Songkla University Hat-Yai Thailand

BACKGROUND: Membrane technology makes it more suitable for the treatment of environmental polluted organic wastewater. Membrane fouling is one of the major concerns in commercial membranes. To overcome this issue, photocatalytic nanomaterials are embedded into the membrane to enhance its surface nature and reusability. In this investigation, polydopamine functionalized graphene oxide (PDA-RGO), graphite carbon nitride (g-C3N4) and PDA-RGO/g-C3N4 nanomaterials were incorporated within polyethersulfone membrane fabricated via a phase inversion technique. These as-prepared membranes’ functional groups and surface morphologies were investigated by Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and field emission electron microscopy (FESEM). These as-prepared membranes were investigated for photocatalytic activity under visible-light-driven photodegradation by environmental pollutants such as Rhodamine B (RhB) and Norfloxacin (NOR). RESULTS: Compared with pristine PES membrane, the PDA-RGO/g-C3N4-PES nanocomposite membrane showed higher photocatalytic activity for Rhodamine B 94.6% and Norfloxacin 96.8%, also reached greater water flux 189 L m−2 h−1. Therefore, the bio-inspired nanocomposite-modified PDA-RGO/g-C3N4 photocatalytic membrane could have huge potential in processing environmentally polluted water. CONCLUSIONS: PDA-RGO/g-C3N4-PES nanocomposite membrane improved the membrane hydrophilicity, water flow, anti-fouling performance, rejection studies and photocatalytic degradation than the pristine membrane. The synergistic result of PDA-RGO and g-C3N4 exhibits better photodegradation efficiency of the membrane towards environmental pollutants. © 2024 Society of Chemical Industry (SCI). © 2024 Society of Chemical Industry (SCI).

关键词： Nanocomposites

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Method on utilization of low quality biogas as a fuel for 4 stroke spark ignition engine of electric generator 11th

Method on utilization of low quality biogas as a fuel for 4 ...

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11th International Conference on Materials and Manufacturing Technology, ICMMT 2020

作者： Negara, I Gede Artha Nindhia, Tjokorda Gde Tirta Surata, I. Wayan Nindhia, Tjokorda Sari Shukla, Shailendra Kumar Master Student at Study Proram of Master in Mechanical Engineering Udayana University Denpasar Bali80361 Indonesia Study Program of Mechanical Engineering Engineering faculty Udayana University Jimbaran Bali80361 Indonesia Faculty of Veterinary Medicine Udayana University Denpasar Bali80113 Indonesia Departmen of Mechanical Engineering IIT Banaras Hindu University Varanasi221005 India

ISBN: (纸本)9783035737226

Biogas quality in many installation of anaerobic digester for processing organic waste are found not optimum, especially in developing country where understanding of anaerobic processing is not well known. The methane content in the biogas are usually low that make it not possible to be utilized as a fuel of the engine. Biogas Purification usually will be introduced as a solution. But this idea is about complicated for simple or small anaerobic digester. Other solution is suggested by using enrichment of biogas by using other fuel such as hydrogen or blended with city gas such as LPG gas. But for preparing hydrogen gas or commercial will also costly. This research introduces simple technique for biogas enrichment by using denatured alcohol. The biogas contents were found around 30% vol. methane (CH4) and around 2% Carbon dioxide (CO2). The price of denatured alcohol is relative cheap because the selling tax is not as much as drinking alcohol. Engine with bigger combustion (420 cc) chamber was prepared for this purpose to make possible to be fuelled with biogas. The compression was set to reach 10 bar. The clearance of the both intake and exhaust valve was set in order to be possible to be running by using biogas. The biogas-air mixer was design for this purpose. The carburetor was set for use of denatured alcohol. It is found that the engine is running well by using biogas fuel that is enriched by using denatured alcohol. The emission was found better comparing using gasoline for the same engine. The fuel consumption is reported for future economic analyses. © 2021 Trans Tech Publications Ltd, Switzerland.

关键词： Carbon dioxide

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Developing an engaging whiteboard animation video for vitamins 4

Developing an engaging whiteboard animation video for vitami...

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4th International Conference on Electrical, Electronics, Informatics, and Vocational Education, ICE-ELINVO 2021

作者： Purwaningsih, S. Anggraeni, A.A. Culinary Science Study Program Faculty of Engineering Universitas Negeri Yogyakarta Indonesia

Whiteboard animation videos are engaging learning media for Generation Z. This study aimed to develop and assess the feasibility of a whiteboard animation video for vitamin in the Nutrition Science subject for class X culinary vocational school. This study was research and development using a 4D approach (define, design, develop, disseminate). The define stage analyzed the curriculum, material, student character, learning media, and school facilities. The design stage included the writing and assessing the material, the writing and assessing of storyboards, and production team selection. The develop stage was making a video and assessing the feasibility. Animation images were created using Paint Tool Sai. Image conversion from JPEG to SVG was performed with Inkscape. The dubber's voice was recorded with Universal Audio using the Apollo Twin audio interface and Avantone CV12 microphone. The audio was edited in Pro Tools 2020.9. To produce a whiteboard animation video, animation images, captions, dubber's voice, and back sound were combined with VideoScribe. Videos used mpg format. In order to maintain video duration below 10 minutes, the video was divided into two parts. The assessment of video feasibility was carried out by one media expert and two content experts. The assessment of feasibility at the disseminate stage was carried out to 30 users. Based on the feasibility assessment, this video was very suitable to be applied as a learning medium. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Animation

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Semi hyper-reduction for nonlinear surface loads on finite element structures by the use of stress modes 38th

Semi hyper-reduction for nonlinear surface loads on finite e...

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38th IMAC, A Conference and Exposition on Structural Dynamics, 2020

作者： Koller, Lukas Witteveen, Wolfgang Pichler, Florian Study Program "Mechanical Engineering" University of Applied Sciences Upper Austria Wels Austria

ISBN: (纸本)9783030476250

The determination of nonlinear state-dependent surface loads, acting on finite element (FE) structures, represents a computationally challenging and costly task in dynamic simulations. While for time integration an enormous reduction of the FE models number of degrees of freedom (DOFs) can be achieved by subspace projection, the computation of nonlinear surface loads usually depends on the non-reduced physical DOFs. In order to overcome this issue, so-called Hyper-Reduction (HR) methods have been introduced. These methods try to compute the surface loads in a reduced subspace as well. In this publication, an intermediate approach is proposed, which is called "Semi Hyper-Reduction" (SHR). The equations for computing the surface loads are built up in the full space and then projected into a lower dimensional subspace via proper force trial vectors. The required force trial vectors, called "stress modes", thereby can be determined a priori without any nonlinear computations using the full DOF model. As a numerical example, a 3D crank drive is used, where the piston and the cylinder are separated by a hydrodynamic lubrication film, which is considered by Reynolds equation. © The Society for Experimental Mechanics, Inc 2021.

关键词： Vectors

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Magnetic and Optical Properties of a-Fe2O3/TiO2 Nanocomposite Derived from Logas Natural Sand for Environmental Application

Magnetic and Optical Properties of a-Fe2O3/TiO2 Nanocomposit...

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2024 International Conference on Applied Sciences and Material Applications, ICASMA 2024

作者： Amiruddin, Erwin Awaluddin, Amir Rini, Ari S. Umar, Lazuardi Rianna, Martha Hadilala, Teguh P. Putri, Novalin Department of Physics Faculty of Mathematics Natural Sciences Riau University Pekanbaru28293 Indonesia Department of Chemistry Faculty of Mathematics Natural Sciences Riau University Pekanbaru28293 Indonesia Department of Physics Faculty of Mathematics and Natural Sciences Universitas Sumatera Utara Medan20155 Indonesia Magnetic Laboratory Faculty of Mathematics and Natural Sciences Riau University Pekanbaru28293 Indonesia Laboratorium Jalan Civil Engineering Magister Study Program Faculty of Civil Engineering Diponegoro University Central Java Semarang50275 Indonesia

In this study, the iron oxide/titanium dioxide (a-Fe2O3/TiO2) nanocomposites derived from Logas natural sand were prepared by ball milling method. The effects of milling time on the magnetic, optical properties and chemical composition of the nanocomposites were investigated using vibrating sample magnetometer (VSM), Uv-Vis spectroscopy and X-ray fluorescence (XRF) spectroscopy, respectively. The magnetization measurement results of all the samples showed the presence of ferromagnetic behaviour characterized by their low coercivity value ranged from 360.10 Oe to 86.50Oe. The optical properties of the samples strongly depend on milling time and showed that the band gaps of the iron oxide/titanium dioxide (a-Fe2O3/TiO2) nanocomposites decrease with increasing milling time. Some other elements such as silicon, aluminium and others were detected, which shows that the milled sample is not purely a-Fe2O3/TiO2 nanocomposites as confirmed by X-Ray Fluorescence. This study demonstrates the simple way of preparing the a-Fe2O3/TiO2 nanocomposites for environmental application. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Milling (machining)

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Trends in citizen influencing willingness to participate in marine debris management and social well-being in Bali metropolitan, Indonesia

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Urban Governance 2024年第4期4卷 362-373页

作者： Suhardono, Sapta Lee, Chun-Hung Suryawan, I Wayan Koko Environmental Sciences Study Program Faculty of Mathematics and Natural Sciences Universitas Sebelas Maret Surakarta 57126 Indonesia Department of Natural Resources and Environmental Studies College of Environmental Studies and Oceanography National Dong Hwa University Taiwan Hualien 97401 Taiwan Department of Environmental Engineering Faculty of Infrastructure Planning Universitas Pertamina Jakarta 12220 Indonesia

In Bali, the high volume of tourists significantly contributes to marine debris, particularly plastics, which threatens the ecological health of beaches and marine life, impacting both tourism and local livelihoods. Effective management is crucial to preserve Bali's natural beauty and sustainability. This study explores the factors influencing the willingness to participate (WTP) in marine debris management among urban communities in the Bali metropolitan area, Indonesia. Utilizing a binary logistic regression model, we examine the impact of key elements for effective marine debris management, risk awareness, learning performance, and higher monthly income and geographic differences between inland and coastal communities. The findings reveal that effective management practices significantly enhance community participation, highlighting the importance of transparency, accountability, and well-organized efforts. Educational initiatives also play a crucial role, with performance in risk awareness and learning showing a marginally significant positive effect on WTP. Conversely, higher income levels negatively influence participation, suggesting a preference for institutional funding over personal contributions. Geographic differences indicate that coastal communities are more inclined to participate than inland communities. These insights provide valuable guidance for policymakers and practitioners in developing strategies to mobilize volunteers, enhance urban resilience, and promote social well-being. By implementing effective management practices, comprehensive educational programs, tailored engagement strategies, and fostering partnerships, urban communities in Bali can become more resilient and actively address environmental challenges. © 2024 The Authors

关键词： Community engagement Debris management Marine sustainability Social well-being Urban resilience

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