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The effect of fiber volume fraction on tensile and impact properties of eleusine indica grass reinforced polypropylene bio composite

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IOP Conference Series: Materials science and engineering 2019年第1期539卷

作者： I P Lokantara N P G Suardana I W Surata I N S Winaya Doctoral Study Program of Engineering Science Faculty of Engineering Udayana University Kampus Sudirman Denpasar-Bali Indonesia Mechanical Engineering Department of Udayana University Street of Bukit Jimbaran Badung Bali Indonesia

The purpose of this research was to investigate the tensile strength and impact strength of eleusine indica grass fiber-reinforced polypropylene recycle composite. In this study, the fiber was treated with alkali at 5% NaOH for 2 hours. The eleusine indica grass fiber cut with a length of 3 cm and the matrix used recycle polypropylene. In this research, the volume fraction of eleusine indica grass fiber varied by 20%, 25%, and 30% respectively. The composite molded with a hot press at temperature 200°C with a holding time for 2 hours. Tensile test used ASTM D3039 and impact test used ASTM D256. The highest tensile and impact strength results on fiber volume fraction 30%.

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Effects of slurry concentration and rotational speeds of drum drier to the characteristics of pregelatinized breadfruit (Artocarpus altilis) flours

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IOP Conference Series: Materials science and engineering 2019年第1期557卷

作者： T C Sunarti W S L Br. Sinaga C Pandji Department of Agroindustrial Technology Faculty of Agricultural Engineering and Technology Bogor Agricultural University Indonesia Program Study of Food Science Faculty of Science and Technology University of Pelita Harapan Tangerang Indonesia

Breadfruit is one alternative carbohydrate source in Indonesia. However, breadfruit is seasonal and climacteric crops; it should be processed immediately to produce flour. Native breadfruit flour has many limitations since it is difficult to be solubilized and swollen in cold water. The flour is modified physically by pregelatinization to improve its properties. Pragelatinized breadfruit flour can be used as instant food, porridge, and baby food. This research is aimed to investigate the effect of slurry concentration (20 and 30%) of native breadfruit flour and rotational speeds (4, 6 and 8 rpm) of double drum drier to the chemical composition and physico-chemical properties of the pregelatinized flours. The results showed that pregelatinization did not influence to the chemical composition. Pregelatinization of the flour improved the water solubility and swelling power on room (30°C) and hot (70°C) solutions, reduced the freeze-thaw stability, caused partial gelatinization which is monitored by losing the birefringence of starch granule, and darkened the flour. The pregelatinization also reduced the gelatinization temperature and had low final viscosity. Low concentration of slurry and low rotation speed of drum increased the gelatinized part of the flour, which is influenced to the cold and hot water solubility.

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Expert system for risk prediction of cesarean section delivery with Dempster Shafer method

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AIP Conference Proceedings 2020年第1期2314卷

作者： Ismaiba Riries Rulaningtyas Katherine Ernawati 1Biomedical Engineering Program Study Faculty of Science and Technology Universitas Airlangga Campus C Zip Code: 60115 Surabaya East Java Indonesia 2Fetomaternal Division of Obstetrics and Gynecology Department Faculty of Medicine Universitas Airlangga Campus A Zip Code: 60131 Surabaya East Java Indonesia

The maternal mortality rate in Indonesia is related to the lack of knowledge of mothers regarding high-risk pregnancies, especially with cesarean delivery. In this case, the prediction system designed is done as an effort to increase the awareness of mothers or women who were preparing for high-risk pregnancies. In this article, an Android-based prediction application will be presented using an expert system with the Dempster Shafer method. This method is based on a mathematical theory which consists of a combination of belief function and plausible reasoning from the risk parameters of each labor class by representing the knowledge obtained from experts. This study uses 16 risk parameters as input based on Poejo Rochati's high-risk pregnancy card with 2 outputs, with risk or no risk of having cesarean delivery. The result obtained from this system is 85%, concludes that the prediction system is able to predict the risk of cesarean delivery.

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Limits on Simultaneous and Delayed Optical Emission from Well-localized Fast Radio Bursts

arXiv

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arXiv 2022年

作者： Hiramatsu, Daichi Berger, Edo Metzger, Brian D. Gomez, Sebastian Bieryla, Allyson Arcavi, Iair Howell, D. Andrew McKinven, Ryan Tominaga, Nozomu Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138-1516 United States The NSF AI Institute for Artificial Intelligence and Fundamental Interactions United States Department of Physics Columbia Astrophysics Laboratory Columbia University 538 West 120th Street New YorkNY10027 United States Center for Computational Astrophysics Flatiron Institute New YorkNY10010 United States Space Telescope Science Institute 3700 San Martin Dr BaltimoreMD21218 United States School of Physics and Astronomy Tel Aviv University Tel Aviv69978 Israel CIFAR Azrieli Global Scholars program CIFAR 661 University Ave. TorontoONM5G 1M1 Canada Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States Department of Physics McGill University 3600 rue University MontréalQCH3A 2T8 Canada McGill Space Institute McGill University 3550 rue University MontréalQCH3A 2A7 Canada National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Physics Faculty of Science and Engineering Konan University 8-9-1 Okamoto Hyogo Kobe658-8501 Japan The University of Tokyo Institutes for Advanced Study The University of Tokyo 5-1-5 Kashiwanoha Chiba Kashiwa277-8583 Japan

We present the largest compilation to date of optical observations during and following fast radio bursts (FRBs). The data set includes our dedicated simultaneous and follow-up observations, as well as serendipitous archival survey observations, for a sample of 15 well-localized FRBs: eight repeating and seven one-off sources. Our simultaneous (and nearly simultaneous with a 0.4 s delay) optical observations of 13 (1) bursts from the repeating FRB 20220912A provide the deepest such limits to date for any extragalactic FRB, reaching a luminosity limit of νLν 1042 erg s−1 ( 2 ×1041 erg s−1) with 15–400 s exposures;an optical-flux-to-radio-fluence ratio of fopt/Fradio 10−7 ms−1 ( 10−8 ms−1);and flux ratio of fopt/fradio 0.02– 2 × 10−5 ( 10−6) on millisecond to second timescales. These simultaneous limits provide useful constraints in the context of FRB emission models, such as the pulsar magnetosphere and pulsar nebula models. Interpreting all available optical limits in the context of the synchrotron maser model, we find that they constrain the flare energies to 1043–1049 erg (depending on the distances of the various repeating FRBs, with 1039 erg for the Galactic SGR 1935+2154). These limits are generally at least an order of magnitude larger than those inferred from the FRBs themselves, although in the case of FRB 20220912A our simultaneous and rapid followup observations severely restrict the model parameter space. We conclude by exploring the potential of future simultaneous and rapid-response observations with large optical telescopes. © 2022, CC BY.

关键词： Pulsars

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Analysis of tsunami hazard in the Southern Coast of West Java Province - Indonesia

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IOP Conference Series: Earth and Environmental science 2020年第1期618卷

作者： W Windupranata N R Hanifa C A D S Nusantara G Aristawati M R Arifianto Research Group of Coastal Ocean and Maritime Engineering Faculty of Earth Sciences and Technology Institut Teknologi Bandung – Indonesia Research Laboratory of Hydrography Faculty of Earth Sciences and Technology Institut Teknologi Bandung Centre for Earthquake Science and Technology Research Centre for Disaster Mitigation Institut Teknologi Bandung Study Program of Geodesy and Geomatics Engineering Faculty of Earth Sciences and Technology Institut Teknologi Bandung

The Southern Coast of West Java Province in the Java Islands is one of prone and exposed area to tsunami hazard. It has about 428 kilometers coastline length, covering 5 administrational regencies (i.e. Sukabumi, Cianjur, Garut, Tasikmalaya, and Pangandaran). It is a strategic area that support many economic activities including tourism, fisheries, electricity power plants, agricultures, markets as well as social factors such as coastal villages, schools and other public facilities. The existence of this strategic area is threatened by the potential for a tsunami disaster mainly from megathrust along the Southern Coast of Java Island. On 2006, a tsunami earthquake of M7.7 occurred off Pangandaran Regency with tsunami height of 5-8 meters and inundated about 500 meters along southern coast of West and Central Java Province. The tsunami caused more than 600 casualties and damage to buildings, public facilities and insfrastructure. Yet, the Indonesia National Earthquake Source and Hazard Map suggest a bigger threat of a plausible M8.7 – M9.2 megathrust earthquake off Java island. This research aims to analyze and map potential areas affected by the tsunami in the South Coast of West Java Province based on numerical modelling carried out with Cornell Multi-grid Coupled Tsunami Model (COMCOT) v1.7 based on the several megathrust earthquake scenarios in southern off West Java. The results of tsunami modelling show that the highest impact is generated in the Sunda Straits & West Java - Central Java Megathrust Scenarios with highest tsunami inundation and the fastest travel time occurred in Cianjur Regency with 26,7 meters height and estimated arrival time of tsunami wave approximately 10 minutes after the mainshock, while the farthest inundation distance is estimated in Sukabumi Regency about 5.8 kilometers from the coast due to existence of river.

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Correction to: Far eastern curlew and whimbrel prefer flying low - wind support and good visibility appear only secondary factors in determining migratory flight altitude

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Movement ecology 2021年第1期9卷 51页

作者： Batbayar Galtbalt Amanda Lilleyman Jonathan T Coleman Chuyu Cheng Zhijun Ma Danny I Rogers Bradley K Woodworth Richard A Fuller Stephen T Garnett Marcel Klaassen Centre for Integrative Ecology School of Life and Environmental Science Deakin University Geelong Victoria Australia. batbr19@***. Threatened Species Recovery Hub National Environment Science Program Research Institute for Environment and Livelihoods Charles Darwin University Ellengowan Drive Casuarina Northern Territory 0909 Australia. Queensland Wader Study Group 22 Parker Street Shailer Park 4128 Australia. Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary Institute of Biodiversity Science School of Life Sciences Fudan University Shanghai 200433 China. Department of Environment Water Land and Planning Arthur Rylah Institute PO Box 137 Heidelberg Victoria 3084 Australia. Australasian Wader Studies Group Melbourne Victoria Australia. School of Biological Sciences University of Queensland Brisbane Queensland Australia. Centre for Integrative Ecology School of Life and Environmental Science Deakin University Geelong Victoria Australia. Victorian Wader Study Group Melbourne Victoria Australia.

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A first-principles study on the quantum tunneling of methylhydroxycarbene isomerization in various solvents

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Journal of Physics: Conference Series 2020年第1期1568卷

作者： E D Susanti F Rusydi I Puspitasari R N Fadilla N D Aisyah A Ahmad Research Center for Quantum Engineering Design Faculty of Science and Technology Universitas Airlangga Jl. Mulyorejo Surabaya 60115 Indonesia Department of Physics Faculty of Science and Technology Universitas Airlangga Jl. Mulyorejo Surabaya 60115 Indonesia Visiting Researcher at Precision Sciences & Technology and Applied Physics Graduate School of Engineering Osaka University Suita 565-0871 Japan Information System Study Program Faculty of Science and Technology Universitas Airlangga Jl. Mulyorejo Surabaya 60115 Indonesia School of Chemical Science and Food Technology Faculty of Science and Technology Universiti Kebangsaan Malaysia Bangi Selangor 43600 Malaysia

Quantum tunneling phenomenon allows a high-barrier reaction to occur even though thermal energy is not sufficient to surmount the barrier. The phenomenon has been suggested to exist in the isomerization of methylhydroxycarbene which occured at 11 K. Here we study the quantum tunneling that occured in the isomerization of methylhydroxycarbene to acetaldehyde and to vinyl alcohol based on density functional calculations. The isomerization pathways are determined under the effect of various solvents which are modeled by polarizable continuum model (PCM). We use Wentzel-Kramers-Brillouin (WKB) approximation to calculate the tunneling probability (T) and extend the usefulness of T into isomerization rate. The results show that the solvents give a significant effect on the isomerization rate of methylhydroxycarbene to acetaldehyde but an insignificant one on the isomerization rate to vinyl alcohol.

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Renewable energy education framework for prospective physics teachers

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AIP Conference Proceedings 2022年第1期2468卷

作者： Dindin Nasrudin Agus Setiawan Dadi Rusdiana Liliasari 1Science Education Universitas Pendidikan Indonesia Jl. Dr. Setiabudhi No.229 Bandung Indonesia 2Physics Education Study Program UIN Sunan Gunung Djati Bandung Jl. AH. Nasution No. 105 Bandung West Java Indonesia 3Department of Mechanical Engineering Education Universitas Pendidikan Indonesia Jl. Dr. Setiabudhi No.229 Bandung Indonesia 4Departement of Physics Education Universitas Pendidikan Indonesia Jl. Dr. Setiabudi No. 229 Bandung Indonesia 5Departement of Chemistry Education Universitas Pendidikan Indonesia Jl. Dr. Setiabudi No. 229 Bandung Indonesia

Teachers play an important role in spreading energy literacy to students at all level of education. Teacher education must be able to provide learning related to renewable energy education. This study aims to describe the framework of renewable energy education for prospective physics teachers. The research method used is Qualitative Document Analysis (QDA), followed up by the Focus Group Discussion (FGD) method. The results show (1) The development of energy education programs at the university level must support the achievement of graduate profiles (2) There are several physics issues or topics at the high school level that are relevant to renewable energy, including climate change, environmentally friendly technology, global warming, and alternative energy (3) There are several global and national policies on renewable energy development that can be accommodated in the program. Renewable energy education framework for prospective teachers must consider four main points: content, context, and learning outcomes (multiple literacy and skills), which are focused on strengthening the profile of graduates. This study recommends the translation of this framework into a more operational and scalable program.

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The analysis of mortar concrete with the variety of sands in jepara (keling sand, bangsri sand) using strong pressure method

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Journal of Physics: Conference Series 2019年第1期1363卷

作者： Yayan Adi Saputro Rachmat Mudiyono Antonius Magister Of Civil Engineering Faculty of Engineering Islamic University of Sultan Agung Semarang Semarang Indonesia Civil Engineering Program Study Faculty of Science and Technology Islamic University of Nahdlatul Ulama Jepara Central Java Indonesia

Along with the increasing of infrastructure development in Indonesia especially in jepara, so the necessary of material also increase, for example: sand. Nowadays, muntilan is the sand that often be used in making infrastructure in the government because it is considered that it has the good quality, whereas in the other hand the river sand is also abundant, but the government perverted mintilan sand as the development material. River sand is usually used by the middle to lower county because the house because the price is cheaper than muntilan sand. After doing this research we hope that: can know the quality of the river sand if it is used in infeastructure, knowing the river sand in jepara that have the good quality, such as: keling sand, bangsri sand, The stages of this research are: preparation, sand inspection (mud content and organic faces, filter analysis, moister content and weight, and specific gravity), making spacimens based on SKSNI 03-6825-2002 ASTM C 305, making compressive strength test. The test result show that at 3,7,14,21,28 days old show that keling sand (93,2 kg/cm2), bangsri sand (135,2 kg/cm2). The use of river sand as the construction material by the government and community will have consequence on the balance kf muntilan sand and river sand. The specific treatment on the river sand will that quality that is almost same as muntilan sand.

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Compressive strength evaluation and phase analysis of pulp capping materials based on carbonate apatite-SCPC using different concentration of SCPC and calcium hydroxide

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Key engineering Materials 2018年 782卷 15-20页

作者： Cahyanto, Arief Restunaesha, Muga Zakaria, Myrna Nurlatifah Rezano, Andri El-Ghannam, Ahmed Department of Dental Materials Science and Technology Faculty of Dentistry Universitas Padjadjaran Jl. Raya Bandung-Sumedang KM 21 Jatinangor45363 Indonesia Graduate Student of Faculty of Dentistry Universitas Padjadjaran Jl. Raya Bandung-Sumedang KM 21 Jatinangor45363 Indonesia Department of Endodontology and Operative Dentistry Program Study of Dentistry Faculty of Medicine Universitas Jenderal Achmad Yani Jl. Terusan Jenderal Sudirman PO BOX 148 Cimahi Indonesia Department of Anatomy Physiology and Cell Biology Faculty of Medicine Universitas Padjadjaran Jl. Raya Bandung-Sumedang KM 21 Jatinangor45363 Indonesia Department of Mechanical Engineering and Engineering Science University of North Carolina at Charlotte CharlotteNC28223 United States

The mechanical strength of pulp capping material based on carbonate apatite and silica calcium-phosphate composite (CO3Ap-SCPC) is one of the key factors for the success of the material in protecting the vitality of the pulp during the formation of apatite and dentin reparative. Modifying the material in the powder phase was known to increase the mechanical strength. The purpose of this study was to determine whether the addition of SCPC and calcium hydroxide in pulp capping materials based on CO3Ap-SCPC would affect the compressive strength of this pulp capping material. In this study, three cement groups were used, each group consisted of dicalcium phosphate anhydrous and vaterite which added by SCPC concentration 0%, 5% and 10% and calcium hydroxide concentration 0%, 5% and 10%, respectively. All groups were tested by a compressive strength test and X-Ray diffraction (XRD) for phase analysis. The mean value of compressive strength with addition of 0% SCPC and 10% Ca(OH)2 was 16.54 ± 1.35 MPa, addition of 5% SCPC and 5% Ca(OH)2 was 18.55 ± 2.81 MPa, addition of 10% SCPC and 0% Ca(OH)2 was 9.22 ± 1.21 MPa. The addition of SCPC and Ca(OH)2 show statistically significant in compressive strength (p2 could improve the mechanical strength and the apatite formation of the CO3Ap-SCPC pulp capping material. © 2018 Trans Tech Publications, Switzerland.

关键词： Compressive strength

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