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Effect of oil palm fiber on physical and tribological behavior of unsaturated polyester-oil palm ash composite

AIP Conference Proceedings 2024年第1期3213卷

作者： Diva Almira Syahrul Humaidi Nurdin Siregar Doli Bonardo Post Graduate Program (Physics) FMIPA Universitas Sumatera Utara Jl. Bioteknologi I Kampus USU Medan 20155 Indonesia Department of Physics Faculty of Mathematics and Natural Science Universitas Negeri Medan Jl. Willem Iskandar Pasar V Deli Serdang 20221 Indonesia Refrigeration and Air Conditioning Engineering Study Program Politeknik Tanjungbalai Jl. Sei Raja Sei Tualang Raso Tanjungbalai 21345 Indonesia

Preliminary studies have successfully been conducted on the physical characterization and tribological behavior of oil palm fiber-reinforced composites based on unsaturated polyester and oil palm ash. In an effort to initiate segregation of composite particles, oil palm ash was used as a segregation agent to increase the surface roughness of the material. The composite preparation method was carried out using the hand lay-up technique for 1 hour at 100 °C. Methyl ethyl ketone peroxide was used as a hardening agent to increase the hardness of the composite. The composite that contained 10 wt.% oil palm fiber reinforced unsaturated polyester-oil palm ash showed the lowest porosity and highest density values compared to the other samples. The decrease in porosity and increase in density can be attributed to the incorporation of 10 wt.% oil palm fiber, which promotes increased segregation of the composite particles, leading to an overall volume increase. Furthermore, the increase in density results in a drastic decrease in the rate of water absorption. The sample with the optimal wear level also had the lowest value compared to the other samples, and this reduction in wear and tear is supported by the high coefficient of friction it exhibits.

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The complete chloroplast genome ofArtocarpus altilis(Moraceae) and phylogenetic relationships

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Mitochondrial DNA Part B 2021年第8期6卷 2291-2293页

作者： Ueric José Borges de Souza Raíssa Nunes dos Santos Renisson Neponuceno de Araújo Filho Gil Rodrigues dos Santos Renato Almeida Sarmento Fabien De Bellis Fabrício Souza Campos a Laboratory of Bioinformatics & Biotechnology Federal University of Tocantins Gurupi Brazil b Department of Forestry Engineering Federal University of Tocantins Gurupi Brazil c Laboratory of Phytopathology Federal University of Tocantins Gurupi Brazil b Department of Forestry Engineering Federal University of Tocantins Gurupi Brazild Post-Graduate Program in Plant Production Federal University of Tocantins Gurupi Brazil e CIRAD UMR AGAP Institute Montpellier Francef UMR AGAP Institute University of Montpellier CIRAD INRAE L’Institut Agro Montpellier France

The chloroplast (cp) is an essential organelle in higher plants. The genes of the plastome are well suited to infer phylogenetic relationships among taxa. In this study, we report the assembly of the cp genome ofArtocarpus altilisand its phylogeny among species from Moraceae family. The cp genome ofA. altiliswas 160,822 base pair (bp) in length, comprising one large single-copy region of 88,692 bp, one small single-copy region of 19,290 bp, and a pair of inverted repeat regions (IRs) of 26,420 bp. A total of 113 different genes were predicted, including 79 protein-coding genes, 30tRNA genes, and fourrRNA genes. The phylogenetic analysis of 19 species belonging to the Moraceae family confirmed the phylogenetic proximity of the genusArtocarpusandMorusand the genetic similarity ofA. camansiandA. altilis.

关键词： Plastid genome plastome phylogenetic relationships

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Piecewise Polynomial Interpolation function approach for solving nonlinear programming problems with disjoint feasible regions: Mathematical proofs

arXiv

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arXiv 2020年

作者： Pinheiro, Ricardo B.N.M. Balbo, Antonio R. Nepomuceno, Leonardo Post-graduate program in Electrical Engineering Engineering Faculty Univ Estadual Paulista - UNESP Bauru–SP Brazil Department of Electrical Engineering in the Engineering Faculty Univ Estadual Paulista - UNESP Bauru–SP Brazil Department of Mathematics Science Faculty Univ Estadual Paulista - UNESP Bauru–SP Brazil

The Piecewise Polynomial Interpolation (PPI) function approach is aimed at solving nonlinear programming problems with disjoint feasible regions. In such problems, disjointedness is generally associated with prohibited operating zones, which correspond to bands of values that a variable is not allowed to assume. An analytical implication of such prohibited operating zones is to make the objective function, as well as its domain, discontinuous. The PPI function approach consists in replacing the constraints associated with prohibited operating zones by an equivalent set of equality and inequality constraints, thereby allowing the application of any efficient gradient-based optimization method for solving the equivalent problem. In this paper, we present the definition of the PPI function and provide the mathematical proofs for its properties. Copyright © 2020, The Authors. All rights reserved.

关键词： Constraint theory

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Need Analysis of Interactive Multimedia Development for Virtual Learning in Pandemic

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Journal of Physics: Conference Series 2021年第1期2111卷

作者： J F Lempas S Soenarto A D Barahama Instructional Technology Post-Graduate Program Universitas Negeri Yogyakarta Jalan Colombo 01 Daerah Istimewa Yogyakarta 55281 Indonesia Department of Electronics and Informatics Engineering Education Post-Graduate Program Universitas Negeri Yogyakarta Jalan Colombo 01 Daerah Istimewa Yogyakarta 55281 Indonesia

The pandemic that has not ended has an impact on changing the educational paradigm. Existing conditions demand to continue to use virtual learning. During the epidemic, this study will examine students' demand for interactive multimedia in virtual learning. The interviews reveal that the media that teachers provide in virtual learning during this pandemic has limits. Data was gathered through interviews and questionnaires given to teachers and students. The student requirements questionnaire reveals that interactive multimedia is the most effective instructional medium for pupils. This study is part of a larger investigation of the evolution of multimedia learning during a pandemic.

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Single-Phase AC-DC-AC Five-level X-type Current Source Converter

Single-Phase AC-DC-AC Five-level X-type Current Source Conve...

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Brazilian Power Electronics Conference, COBEP

作者： Louelson A. Costa Montiê A. Vitorino Maurício B. R. Corrêa Post-Graduate Program in Electrical Engineering Federal University of Campina Grande Campina Grande Brazil

ISBN: (数字)9781728141800

ISBN: (纸本)9781728141817

In this paper a new single-phase AC-DC-AC five- level X-type current source converter is proposed. The use of the X-type topology reduces the conduction losses of the converter, whilst the five-level configuration may reduce the total harmonic distortion under lower frequencies, and allows the increase of the power capability of the converter. The novelty of this paper resides on the multilevel configuration being applied to a X-type current source converter. The operation and sine- triangle pulse-width modulation of the proposed converter are presented, as they are validated by simulation results. Besides that, experimental results for the rectifier side (AC-DC) are presented.

关键词： Topology Inductors Synchronization Switches Modulation Oscillators Inverters

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An assessment of rolled stainless steel angles under compression 7th

An assessment of rolled stainless steel angles under compres...

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7th International Conference on Structural engineering, Mechanics and Computation, 2019

作者： da Sirqueira, A.S. da Vellasco, P.C.G.S. de Lima, L.R.O. da Silva, A.T. Rodrigues, M.C. Vellasco, M.M.B.R. PGECIV-Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Electrical Engineering Department PUC-Rio – Pontifical Catholic University of Rio de Janeiro Brazil

ISBN: (纸本)9781138386969

Stainless steel has been used in several types of constructions. Although many of their mechanical properties are similar to the properties of carbon steel, their nonlinear characteristics imply in different design rules. This non-linearity mainly affects the response to local and flexural buckling. The Eurocode 3: Part 1-4 (2006) stainless steel design standard can be applied to hot rolled, welded and cold formed products, but the provisions of this code are rather conservative, with a limited application due to the lack of experimental data. Thus, one of those areas that require attention and study concerns the behaviour of columns made of rolled stainless steel angles. This paper describes an experimental campaign made on rolled stainless steel angles under axial compression. The tests were performed on stainless steel rolled angles with lengths varying from 150 mm to 1400 mm while the collapse involved: flexural-torsional and flexural buckling modes. © 2019 Taylor & Francis Group, London, UK.

关键词： Hot rolling

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Data analysis and data warehouse design based on Pentaho data integration (kettle) to support the determination of student learning achievement

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IOP Conference Series: Materials Science and engineering 2021年第5期1098卷

作者： A D Barahama R Wardani Electronics and Informatics Engineering Education Post-Graduate Program Yogyakarta State University Jalan Colombo 01 Daerah Istimewa Yogyakarta 55281 Indonesia

Data analysis has become a vital requirement in various fields. The results of data analysis can be used as a data warehouse design that is expected to help in solving problems, evaluating learning outcomes and supporting decision making. In the field of education, student achievement is a reference for achieving quality learning. This success can be seen from the achievement of student learning completeness that is the basis for evaluating and making decisions. The data warehouse design can be used as a basis in knowing student learning progress that can be seen from the value obtained. The diversity of data makes managing values difficult and delayed, data warehouse design using Pentaho can help and simplify data integration. The results of the analysis and design of the data warehouse will be presented in a multidimensional form that can be seen through dimension tables and fact tables.

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Design alternative on peat soil

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IOP Conference Series: Materials Science and engineering 2020年第1期1007卷

作者： Vicky Muroby Chaidir Anwar Makarim Civil Engineering Post-graduate Program Faculty of Engineering Universitas Tarumanagara

Construction on peat soil has its own difficulty and challenge due to its properties of low shear strength, high compressibility, high water content, and flammable material. Indonesia ranked 4th on peat land area around the world after Canada, Russia, and United States. Based on recent mapping, peat land covers 14,9 million hectare in Indonesia. This paper presents the finding from literature studies regarding peat soil, construction on peat soil, case studies for road infrastructure construction on peat soil at West Borneo, Indonesia, and provide analysis and recommendation for the problems faced. Construction on peat soil requires special attention, especially on the design and execution. In the event where construction must be performed on a peatland which thickness is < 3m, the approach recommended is peat removal and replacement. If the peat thickness is 3-10 m, adopt the preloading, construction with vertical and sand drain, lightweight fills, surface mattress, stone column, etc. If the peat thickness is < 10m, use pile as foundation. Unit price contract is preferable over lumpsum contract due to the high uncertainties of peat soil. Environment impact due to construction on peat soil need to be accounted for, also the risk of peat fires need to be considered if dewatering used.

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Effect of low temperature and period of storage on the quality of Garlic Seeds (Allium sativum L) 1

Effect of low temperature and period of storage on the quali...

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1st International Conference on Mechanical Electronic and Biosystem engineering, MEBSE 2018

作者： Nurmalia, N. Purwanto, Y.A. Sobir, S. Sulassih, S. Naibaho, N. Post Graduate Program of Postharvest Technology Department of Mechanical and Biosystem Engineering Bogor Agricultural University Indonesia Center of Tropical Horticulture Studies Bogor Agricultural University Indonesia Department of Agronomy and Horticulture Bogor Agricultural University Indonesia

The aim the study was to analyze the effect of temperature storage of garlic seeds including weight loss, sprouting and damage during the storage period. The samples of Garlic seeds are local varieties, cv. Lumbu Hijau and cv. Lumbu Kuning were collected from the farmers in Temanggung Regency. The experiments were set at two different temperature conditions, i.e. 5°C and room temperature (29-31°C) as a control. The relative humidity (RH) of storage conditions was 50-70% for cold storage and 70-80% for storage in room temperature. The amout of sampel used was about 47-68 tubers (500 g) for cv. Lumbu Hijau and around 24-32 tubers (500 gr) for cv. Lumbu Kuning, were placed in cold storage at different temperatures and in dark. The period of storage was design for 5 months. All experiments were carried out in three replications. The results showed that the decrease in weight loss for garlic stored at storage temperatures of 5°C and room temperature were 10.48 and 7.46 % for cv. Lumbu Hijau and 15.03 and 11.38 % cv. Lumbu Kuning, respectively. The higest sprouting percentage was found for those seeds garlic cv. Lumbu Kuning at 5°C, i. e, 22.22 %. The highest percentage of damage after 5 months of storage was found in the seeds of garlic cv. Lumbu Hijau stored at room temperature were 2.30 % and cv. Lumbu Kuning at 5°C were 19.04 %. © Published under licence by IOP Publishing Ltd.

关键词： Cold storage

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Spatial pattern of sediment transport for analysis of precipitation direction and magnitude in the upper Lematang river sub-basin 4

Spatial pattern of sediment transport for analysis of precip...

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4th Geomatics International Conference 2019, GeoICON 2019

作者： Sarino Yuono, Agus Lestari Putranto Dinar, D.A. Civil Engineering and Planning Study Program Faculty of Engineering University of Sriwijaya Jl. Raya Inderalaya Km. 32 Ogan Ilir Regency Inderalaya South Sumatera Province Indonesia Civil Engineering Post Graduate Study Program Faculty of Engineering University of Sriwijaya Jl. R. Soeprapto Bukit Besar Palembang City South Sumatera Province Indonesia

The high level of erosion that occur in Musi river basin has improved a tremendous impact on sedimentation in downstream areas and has resulted in many infrastructure of water is disturbed, such as silting of irrigation channels, siltation of rivers which disrupt the flow of transport stream and increasing the risk of flooding, high sedimentation in the port basin, low quality of water and the rising costs of water treatment. This study utilizes techniques terrain models Digital (Digital Elevation Model/DEM) to analysis the spatial distribution of the potential for erosion and sources of sedimentation, as well as the direction of the flow of sediment into channels as well as its relationship with outlet in branching river as the supplies to be sediment to the river flow. The method used in this study using a spatial model analysis with the help of GIS in analysing and presenting the level of erosion and deposition by utilizing modelling slope and kinetic energy of rainfall to estimate the index erosivity and distribution pattern of sediment into the river channel. This research was conducted at the upper Lematang river sub basin with area 412,638 Ha, which are classified into 11 sub-chatments with the highest altitude is 3.159 m above sea level (Dempo Valley) and the lowest is 126 m above sea level (Talang tinggi Valley). Analytical results have been tested by taking a fine sediment sampling in each sub-watershed in the analysis and is taken along the channel network and compare the observed patterns with the results predicted by the model analysis of soil erosion. Overall, erosion by high intensity tends to occur in the relationship between the different vegetation coverage, the barren land and open land used for farms and land used for mining. Approximately 45-65.5% slope bad condition because the vegetation has been open, so it can be seen the amount of erosion in the area is 2.139 ton/ha/year, at the sloping is 1.8239 ton/ha/year. © 2019 Published under licence

关键词： Erosion

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