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Simulation and experimentation of Propeller-Savonius turbine tested underwater surface

CLEAN ENERGY 2024年第3期8卷 20-33页

作者： Wuryanti, Sri Sasono, Teguh Manunggal, Bambang P. Mursanto, Wahyu B. Sugianto politekn negeri Bandung Politeknik Negeri Bandung Bandung Indonesia politekn negeri padang Dept Mech Engn Padang Indonesia

Indonesia's vast maritime territory offers a unique opportunity for harnessing the potential Energy of seawater currents. This study explores the effectiveness of a combined Savonius and propeller-type turbine system. The Savonius turbine, known for its efficiency in capturing ocean currents due to its large sweep area, is combined with a propeller-type turbine to enhance rotational speed and power generation. A novel approach is employed to induce turbulence and optimize energy extraction, first channeling water through the propeller turbine and then into the Savonius turbine. A comprehensive investigation is conducted through simulations and experimental tests within a controlled tunnel environment. The study explores the performance of two-bladed and three-bladed Propeller-Savonius configurations at varying inlet water velocities (0.1, 0.3, 0.6 and 1.0 m/s). The simulation incorporates a turbulence model with 5% intensity and a hydraulic diameter of 0.216 m. Results indicate that the proposed configuration achieves a maximum power output of 2.0293 W with an impressive efficiency of 63.339% in simulation. Concurrently, experimental testing yields a peak efficiency of 61.335% and turbine power of 0.3951 W. The findings demonstrate the feasibility of the combined turbine system and highlight the importance of turbulence in optimizing energy extraction from seawater currents. This research contributes valuable insights into the design and performance of hybrid turbines for harnessing oceanic Energy, emphasizing the potential for sustainable power generation in maritime regions. The methodology and results presented herein offer a foundation for further exploration and refinement of seawater current energy conversion technologies. The study combines a Savonius turbine and a propeller turbine to enhance rotational speed and power generation. CFD simulations and experiments document performance at different water velocities. The findings show that this system is promisi

关键词： hydro-turbine propeller -Savonius renewable energy water WIND TURBINE PERFORMANCE BLADES CFD RATIO

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The Effect of Uncaria gambir on Optical Properties and Thermal Stability of CNF/PVA Biocomposite Films

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Journal of Renewable Materials 2024年第9期12卷 1593-1603页

作者： Remon Lapisa Anna Niska Fauza Dieter Rahmadiawan Krismadinata Dori Yuvenda Randi Purnama Putra Waskito Nandy Putra Hairul Abral Mechanical Engineering Department Universitas Negeri PadangPadang25173Indonesia Centre for Energy and Power Electronics Research Universitas Negeri PadangPadang25173Indonesia Department of Mechanical Engineering National Cheng Kung University(NCKU)Tainan70101Taiwan Mechanical Engineering Department Universitas IndonesiaDepok16424Indonesia Mechanical Engineering Department Universitas AndalasPadang25163Indonesia

Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding *** all types of cellulose materials available,cellulose nanofiber(CNF)has great potential to be utilized in a diverse range of applications,including as a film *** this study,CNF biocomposite film was prepared by using polyvinyl alcohol(PVA)as a matrix and Uncaria gambir extract as a *** study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced *** formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy,their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter,while their reflectance was determined using a reflectance *** results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties,as indicated by the lower percentage of transmittance in the visible region,10%–70%.In addition,its reflectance increased to 10.6%compared to the CNF film without the addition of Uncaria gambir ***,the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400℃–500℃.In conclusion,the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.

关键词： Cellulose nanofiber biocomposite film optical properties Uncaria gambir thermal stability

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Enhanced Dye Adsorption and Bacterial Removal of Magnetic Nanoparticle-Functionalized Bacterial Cellulose Acetate Membranes

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Journal of Renewable Materials 2024年第9期12卷 1605-1624页

作者： Heru Suryanto Daimon Syukri Fredy Kurniawan Uun Yanuhar Joseph Selvi Binoj Sahrul Efendi Fajar Nusantara Jibril Maulana Nico Rahman Caesar Komarudin Komarudin Centre of Advanced Material for Renewable Energy(CAMRY) Universitas Negeri MalangMalang65145Indonesia Department of Mechanical and Industrial Engineering Universitas Negeri MalangMalang65145Indonesia Department of Food and Agricultural Product Technology Faculty of Agricultural TechnologyAndalas UniversityPadang25163Indonesia Department of Chemistry Institut Teknologi Sepuluh NopemberSurabaya60111Indonesia Study Program of Aquatic Resources Management Faculty of Fisheries and Marine ScienceBrawijaya UniversityMalang65145Indonesia Institute of Mechanical Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical Sciences(SIMATS)Saveetha UniversityChennai602105India Faculty of Vocational Universitas Negeri MalangMalang65145Indonesia

Utilizing biomass waste as a potential resource for cellulose production holds promise in mitigating environmental *** current study aims to utilize pineapple biowaste extract in producing bacterial cellulose acetate-based membranes with magnetic nanoparticles(Fe_(3)O_(4)nanoparticles)through the fermentation and esterification process and explore its *** bacterial cellulose fibrillation used a high-pressure homogenization procedure,and membranes were developed incorporating 0.25,0.50,0.75,and 1.0 wt.%of Fe3O4 nanoparticles as magnetic nanoparticle for *** membrane characteristics were measured in terms of Scanning Electron Microscope,X-ray diffraction,Fourier Transform Infrared,Vibrating Sample Magnetometer,antibacterial activity,bacterial adhesion and dye adsorption *** results indicated that the surface morphology of membrane changes where the bacterial cellulose acetate surface looks *** crystallinity index of membrane increased from 54.34%to 68.33%,and the functional groups analysis revealed that multiple peak shifts indicated alterations in membrane functional ***,adding Fe_(3)O_(4)-NPs into membrane exhibits paramagnetic behavior,increases tensile strength to 73%,enhances activity against *** and ***,and is successful in removing bacteria from wastewater of the river to 67.4%and increases adsorption for anionic dyes like Congo Red and Acid Orange.

关键词： Bacterial cellulose dye adsorption Fe3O4 nanoparticles membrane pineapple waste

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Spirooxindoles:Recent report of green synthesis approach

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Green Synthesis and Catalysis 2024年第1期5卷 1-13页

作者： Agus Rimus Liandi Antonius Herry Cahyana Diva Naufal Alfariza Rahma Nuraini Renita Wulan Sari Tio Putra Wendari Department of Chemistry Faculty of Science and TechnologyUniversitas Islam Negeri Syarif Hidayatullah JakartaTangerang Selatan 15412Indonesia Department of Chemistry Faculty of Mathematics and Natural SciencesUniversitas IndonesiaDepok 16424Indonesia Department of Chemistry Faculty of Mathematics and Natural SciencesUniversitas AndalasPadang 25163Indonesia

Spirooxindole is a compound with a unique framework and broad bioactivities in *** this study,we have reviewed various approaches or methods in synthesizing spirooxindole derivatives focused on green *** of spirooxindoles is mainly carried out through multicomponent reactions combined with various green approaches such as the use of heterogeneous catalysts(nano-sized,magnetic,metal-complex,and metal-organic framework catalysts),deep eutectic solvent,solvent-free reactions,catalyst-free reactions,as well as the use of ultrasonic and microwaves *** green method is carried out in addition to obtaining high yields,it also offers reductions in the use of hazardous chemicals,energy use,purification processes,and waste *** a result,green synthesis methods in the synthesis of spirooxindole derivatives are more environmentally friendly.

关键词： Spirooxindoles Green synthesis Catalysis Nanoparticle Ultrasonic irradiation

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Generalized Normalized Euclidean Distance Based Fuzzy Soft Set Similarity for Data Classification

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Computer Systems Science & Engineering 2021年第7期38卷 119-130页

作者： Rahmat Hidayat Iwan Tri Riyadi Yanto Azizul Azhar Ramli Mohd Farhan Md.Fudzee Ansari Saleh Ahmar Faculty of Computer and Information Technology Universiti Tun Hussein Onn MalaysiaBatu PahatMalaysia Department of Information Technology Politeknik Negeri PadangPadangIndonesia Department of Information System Universitas Ahmad DahlanYogyakartaIndonesia Department of Statistics Universitas Negeri MakassarMakassarIndonesia

Classification is one of the data mining processes used to predict predetermined target classes with data learning *** study discusses data classification using a fuzzy soft set method to predict target classes *** study aims to form a data classification algorithm using the fuzzy soft set *** this study,the fuzzy soft set was calculated based on the normalized Hamming *** parameter in this method is mapped to a power set from a subset of the fuzzy set using a fuzzy approximation *** the classification step,a generalized normalized Euclidean distance is used to determine the similarity between two sets of fuzzy soft *** experiments used the University of California(UCI)Machine Learning dataset to assess the accuracy of the proposed data classification *** dataset samples were divided into training(75%of samples)and test(25%of samples)*** were performed in MATLAB R2010a *** experiments showed that:(1)The fastest sequence is matching function,distance measure,similarity,normalized Euclidean distance,(2)the proposed approach can improve accuracy and recall by up to 10.3436%and 6.9723%,respectively,compared with baseline ***,the fuzzy soft set method is appropriate for classifying data.

关键词： Soft set fuzzy soft set classification normalized euclidean distance similarity

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Numerical analysis of horizontal temperature distribution in large buildings by thermo-aeraulic zonal approach

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Building Simulation 2022年第1期15卷 99-115页

作者： Nisrine Laghmich Zaid Romani Remon Lapisa Abdeslam Draoui FSTT-ETTE-UAE/U 70FST-Abdelmalek Essaadi University BP 416 TangierMorocco LaRAT National School of Architecture of TetouanMorocco Faculty Engineering Universitas Negeri PadangPadangIndonesia

The commercial and public services sectors including shopping centers,worship buildings,theatres,and other types,account for more than 20%of the electricity consumption in the *** building typologies are characterized by large spaces and high and temporary ***,the horizontal temperature distribution in these buildings becomes one of the important parameters on occupant's comfort and energy *** the present study,a thermo-aeraulic zonal model using TRNSYS and CONTAM simulation tools is developed to analyze the spatial temperature distribution in a large *** studies relating to mesh discretization of building volume are performed to optimize the computational time and *** computational simulation is carried out to analyze the impact of building height,internal loads,natural ventilation and climatic conditions on the spatial temperature distribution,building energy performance,and thermal *** developed simulation model in this study is effective to predict the horizontal temperature distribution with reasonable computation time compared to CFD *** results show that the internal heat gains lead to an increase in the horizontal temperature gradient which should not be negligible especially in the case of large *** the other side,natural night ventilation can reduce the peak tempearture in building by 3℃ for normal occupation building with limited internal ***,good spatial temperature distribution can decrease annual building energy needs about 32%.It can be helpful for architects and building developers to make an optimal choice regarding to building envelope and HVAC design.

关键词： building simulation mesh grid discretization thermo-aeraulic zonal model-large building spatial temperature distribution

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The Influence of Hedonistic Culture to Minangkabau Juveniles’Social Behaviors in the Twenty-first Century

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Fudan Journal of the Humanities and Social Sciences 2021年第3期14卷 465-481页

作者： Remiswal Remiswal Martin Kustati Besral Besral Zainimal Zainimal Arham Junaidi Firman Department of Islamic Education Faculty of Teacher Training and EducationUniversitas Islam Negeri Imam Bonjol Padang’PadangWest SumatraIndonesia Department of English Education Faculty of Teacher Training and EducationUniversitas Islam Negeri Imam Bonjol PadangPadangWest SumatraIndonesia Department of Islamic Broadcasting Communication Faculty of DakwaUniversitas Islam Negeri Imam Bonjol PadangPadangWest SumatraIndonesia

This study is based on the emergence of teenagers1 behaviors which is deviated from the tradition of Minangkabau *** aims to determine how hedonism affects Minangkabau's local pearls of wisdom.A qualitative approach with phenomenology research design was used where 25 Minangkabau teenagers,religious and traditional leaders who live in Lima Puluh Kota,Tanah Datar,and Agam involved in the *** data taken from observation,interview,and *** results reveal that the paradigm shift of young Minangkabau's social behavior is caused by hedonism that can be seen in both positive and negative *** positive ways,they live their lives mainly to fulfill their needs,add experiences,create a sense of secure for the community,and be open ***,in negative ways,traditions based on Islamic laws and the Holly Quran were regarded only as *** hedonism tends to trigger crime,individualism,laziness,free-sex,insecurity,and ***,this kind of behavior was caused by the absence of religious and custom education they had in the family and social lives.

关键词： Hedonistic culture Local wisdom Minangkabau juwcmle Social behaviors Social lives

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An English as a Lingua Franca(ELF) Perspective in Asian English Language Teaching

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Chinese Journal of Applied Linguistics 2016年第4期39卷 401-420,498页

作者： Salam MAIRI Universitas negeri padang Indonesi

The global spread of English as a Lingua Franca （ELF） has implications for practice in English Language Teaching （ELT） classrooms. This paper presents a study on attitudes toward ELF which is crucial to its incorporation because attitudes influence the learning output in ELT. It uses a mixed method approach through a questionnaire survey on attitudes toward ELF, which contains a modified Verbal Guise Technique （VGT）, complemented with semi-structured interviews. Seventy university students and 4 lecturers from three English departments in Japan （Waseda University and Sophia University） and Indonesia （Universitas negeri Jakarta） were involved in filling out the questionnaire and semi structured interview sessions. The results highlight positive attitudes towards ELF and its incorporation into ELT （Japan： 3.71, and Indonesia： 3.51）. In addition, factors which influence these attitudes （aspects related to language learning experience） were proven significant. The interview sessions also suggest ways to incorporate an ELF perspective into the ELT classrooms. Further, it addresses the issue of the gap between theory and practice in research on Global Englishes in Language Teaching （GELT） where a ＂conceptual gap＂ is often found. The study is of value to those interested in ELT curriculum evaluation and design to meet the needs of both ELT and ELF community in countries like Japan and Indonesia.

关键词： English as a lingua franca (ELF) verbal guise technique (VGT) global Englishes in language teaching (GELT)

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Hydrothermal synthesis of ABi_(2)Ta_(2)O_(9)Aurivillius phase:A comparative study of A-site cation size on structure,dielectric,optical properties

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Journal of Advanced Dielectrics 2022年第2期12卷 1-7页

作者： Ilona Bella Tio Putra Wendari Novesar Jamarun Nandang Mufti Zulhadjri Department of Chemistry Universitas AndalasKampus Limau ManisPadang 25163Indonesia Center of Advanced Materials for Renewable Energy Universitas Negeri Malang Jl.Semarang 5Malang 65145Indonesia

In this study,the double-layered Aurivillius phases CaBi_(2)Ta_(2)O_(9)(CBT)and PbBi_(2)Ta_(2)O_(9)(PBT)were prepared through a hydrother-mal route with NaOH as a *** analysis confirmed that the CBT and PBT compounds were successfully formed and adopted an orthorhombic crystal structure with an A21am *** Bail refinements of XRD data indicated that the unit cell volume of CBT was smaller than PBT and is associated with the smaller ionic radius of Ca^(2+)compared to Pb^(2+).The surface mor-phology of both samples,as determined using SEM,demonstrated plate-like grains with anisotropic grain *** was found that the different ionic radii of A-site cations(Ca^(2+)and Pb^(2+))strongly affected the structural,optical and electrical properties of the Aurivillius *** occupation of smaller Ca^(2+)cations induced a higher structural distortion,which resulted in higher bandgap(Eg)energy and ferroelectric transition temperature(Tc)of CBT,compared to those of PBT.

关键词： Aurivillius phase hydrothermal synthesis Le Bail refinement relaxor-ferroelectric anisotropic grain optical properties

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Long-Term Land Deformation Monitoring Using Quasi-Persistent Scatterer (Q-PS) Technique Observed by Sentinel-1A: Case Study Kelok Sembilan

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Advances in Remote Sensing 2018年第4期7卷 277-289页

作者： Pakhrur Razi Josaphat Tetuko Sri Sumantyo Daniele Perissin Hiroaki Kuze Physics Department Universitas Negeri Padang Sumatra Indonesia Center for Environmental Remote Sensing Chiba University Chiba Japan Lyle School of Civil Engineering Purdue University West Lafayette IN USA

Located on the mountainous area, Kelok Sembilan flyover area in West Sumatra, Indonesia has a long history of land deformation, therefore monitoring and analyzing as continuously is a necessity to minimize the impact. Notably, in the rainy season, the land deformation occurs along this area. The zone is crucial as the center of transportation connection in the middle of Sumatra. Quasi-Persistent Scatterer (Q-PS) Interferometry technique was applied for extracting information of land deformation on the field from time to time. Not only does the method have high performance for detecting land deformation but also improve the number of PS point, especially in a non-urban area. This research supported by 90 scenes of Sentinel-1A (C-band) taken from October 2014 to November 2017 for ascending and descending orbit with VV and VH polarization in 5 × 20 m (range × azimuth) resolution. Both satellite orbits detected two critical locations of land deformation namely as zone A and Zone B, which located in positive steep slope where there is more than 500 mm movement in the Line of Sight (LOS) during acquisition time. Deformations in the vertical and horizontal direction for both zone, are 778.9 mm, 795.7 mm and 730.5 mm, 751.7 mm, respectively. Finally, the results were confirmed by ground truth data using Unmanned Aerial Vehicle (UAV) observation.

关键词： Interferometry Synthetic Aperture Radar Land Deformation Q-PS Technique Kelok Sembilan

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