bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of Antibiotic-Producing Bacteria from Extreme Microhabitates in Mangrove Ecosystem
Authors: Effendi Irwan , Tanjung Afrizal , Sari Desy Mutia
Published: November 2020

This study aims to isolate and identify the antibiotic-producing bacteria from extreme microhabitates in the marine ecosystem against fish pathogenic bacteria (V. alginolyticus, A. hydrophila, dan Pseudomonas sp). Microbes from samples were grown on NA and TSA media. Well grown colonies were examined for their ability to produce antibiotics against the pathogens by the streaking and paperdisc diffusion method on MHA. Potential isolates were identified through a series of phenotypic and genotypic test. A number of 4 antibiotic-producing bacteria were selected. DNA of the bacteria were extracted using DNA easy mini column and amplified by using Kappa PCR kit with 16S rDNA 1A and 16S rDNA2A primers. The PCR results were analyzed on a 1.5% agarose gel in Tris-acetat-EDTA (TAE) electrophoresisuffer (4 mM Tris-acetate and 1 mM disodium EDTA at pH 8.0). The electrophoresis process was carried out at 60 mA (100-120 v) for 30-45 minutes read by UV Transilluminator. Isolate Ni5 have a 99% homological similarity to Bacillus amyloliquefaciens strain SH20. Bacterial isolate Xy3 has a 100% homological similarity with Bacillus cereus strain NY180. Isolate S11 has a 97% homological similarity with Enterobacter hormaechei strain CGAPGPBBS-064. Isolate K22 has a 99% homological resemblance to Klebsiella pneumoniae strain MW-W 754.
Thermal Inactivation of Eupenicillium Javanicum Ascospores in Pineapple Juice: Effect of Temperature, Soluble Solids and Spore Age
Authors: Evelyn  , Chairul  , Muria S R , Adella L , Ramadhani R
Published: November 2020

Food spoilage leading to food waste and substantial economic losses is a major issue for the food industry. The spoilage is often due to bacterial and fungal contamination in foods. Spores from microorganism pose a great concern since they can survive pasteurization and grow in specific foods. The obj1ectives of this work were to investigate the effect of temperature (T: 80-90°C), soluble solid concentration (11–20°Brix), and spore age (30–60 days) on the log reductions of Eupenicillium javanicum ascospores in pineapple juice. It was also carried out to estimate the first-order kinetic parameters (D and z-values) from the log survivor curves. Increasing the temperature from 80 to 90°C for 10 min increased the spore inactivation in 11°Brix pineapple juice by 6.4 log. For 5-log inactivation, increasing the percentage weight (% wt.) of sucrose from 11°Brix to 20°Brix at 90°C, increased the time needed to inactivate the spores by 2.6 min. Likewise, increasing the age of ascopores from 30 days to 60 days, also increased the time required by 16.7 min. The estimated D-values for 30-days old spores in 11°Brix juices were 19.84 min at 80°C, 4.99 min at 85°C and 1.45 min at 90°C, with z-values of 8.6-8.8°C. The results obtained provide useful data to design and predict pasteurization process targeting E. javanicum ascospores.
Some structural patterns of the stand of Scotch pine (Pinussylvestris L.) in the conditions of Zavolzhsky - ObshchySyrt province
Authors: Rjabuchina M.V. , Ryabinina Z.N. , Kalyakina R.G. , Gerasimenko V.V. , Maiski R.A.
Published: November 2020

Under the structure of stands is understood the order of combination and the nature of the relationship of the trees that make them up according to the main taxation characteristics, both in statics and dynamics.Since the stand is an unified system where the growth and development of trees are closely interconnected, the study of the structure should be carried out for the entire set of trees without separating any of its constituent parts, as indicated by N.V. Tretyakov.A.A. Makarenko proposed a methodology for studying the structure of stands, based on the construction of distribution curves for 10 classes within the range of variation of taxation features.In the present work, it was found that the distribution of actual values within 9 or 11 steps does not significantly affect the statistics of the distribution series calculated on the same trial plots for 10 classes, and with an increase or decrease in the classes, the difference between these statistics will increase accordingly.
Morphological Variation of Castor Bean (Ricinus communis L.) on Peatland Area in Kepulauan Meranti Riau Indonesia
Authors: Wahibah Ninik Nihayatul , Fitmawati  , Yahya Vanda Julita , Perdana Muhammad Agung , Budiono Rahmat
Published: November 2020

Castor (Ricinus communis L.) has been reported as source of raw material for various products, including biofuel, cosmetic and pharmaceutical industries. This plant is known as an adaptive plant which perform well-growth and development in unfertile soil. We observed that castor plants grow and develop in Kepulauan Meranti, Riau Province, Indonesia where peatland mostly dominates. Objective of the study was to evaluate genetic diversity of castor bean germplasm in Kepulauan Meranti grown in fired-peatland area based on morphological characters. Sampled plants were tagged and parts of plant were photographed and characterized. Some plant organs such as leaves and fruits were taken for more identification. We observed 12 castor accessions showing distinctive phenotypes. Morphological characters that varied among genotypes were plant architecture; stem anthocyanin; stem wax; stem color; adaxial leaf surface; fruit wax; form of racemic; main seed coloration; secondary coloration of seed; and type of secondary coloration of seed. All genotypes showed prickle existence on fruit surface. The result indicates that castor germplasm in Kepulauan Meranti serve diverse genetic variability. Further studies including assessment based on agronomic, biochemical and molecular approaches are still required for supporting castor breeding program to develop new cultivars particularly that adaptive to peat soil area.
Antidiabetic Activity of Triterpenoids from Anisophyllea disticha
Authors: Fikriyah Miftahul , Almurdani Muhammad , Eryanti Yum , Teruna Hilwan Y.
Published: November 2020

Diabetes and its complication are strongly associated with mortality and morbidity rate in Indonesia. The number of diabetes patients is expected to increase every year. α-Glucosidase enzyme inhibitor widely used for treatment of diabetes. It may be obtained by isolation of Indonesian medicinal plants. As medicinal plant which is used by Talang Mamak tribe, Rakit Kulim, Indragiri Hulu, Riau, Anisophyllea disticha has its own attraction to study because its potential secondary metabolites have never been reported scientifically. Therefore, this study aims to determine antidiabetic activity by α-glucosidase inhibition method of metabolites this plant. The isolation of metabolites was based on solvent polarity fractionation by vacuum liquid chromatography method on ethyl acetate extract. Chemical structures of the metabolites were elucidated based on spectroscopic characteristics, included FTIR and 1D H-NMR. The isolated compounds were assumed to be two triterpene derivatives. The IC50 of compound 1, compound 2, and acarbose as a positive control were 46.246 ± 0.166, 80.273 ± 0.08 and 19.737 ± 0.046, respectively. Therefore it can be concluded that both compounds have potential as antidiabetic.
Transesterification of Crude Palm Oil (CPO) to Biodiesel Using Heterogeneous Catalyst K-CaO from Anadara Granosa Synthesized by Sol Gel Method
Authors: Maisarah  , Nurhayati  , Linggawati Amilia
Published: November 2020

This study aimed to synthesize biodiesel from CPO using heterogeneous K-CaO catalyst from blood cockle (anadara granosa) shells. The catalyst was synthesized by sol gel method with variation calcination temperatures of 700, 800 and 900°C. The catalyst was characterized using X Rays Diffraction (XRD) and X-Ray fluorescence (XRF). The XRD results showed the presence of mineral lime, portlandite and calcite. Based on the XRF results that K-CaO heterogeneous catalyst contained 96,538% of calcium oxide (CaO). Biodiesel was synthesized by transesterification reaction with variations in time conditions (1, 2, 3 and 4 hours) and reaction temperature (50, 55, 60 and 65°C). The maximum biodiesel yield of transesterification reaction using heterogeneous K-CaO catalyst from blood cockle shell (anadara granosa) was 92,648% using catalyst calcination at a temperature of 700 °C and the optimum reaction time was 2 hours using 3% (w/w) catalyst, mol ratio of oil: methanol 1:6, stirring speed of 500 rpm and reaction temperature of 60 °C.
Biomass Extraction as Green Corrosion Inhibitor for Low Carbon Steel in Hydrochloric Acid Solution
Authors: Komalasari  , Zultiniar  , Karim Abdul Rahman Marwis , Susanto Reno , Azhari Ilman , Utami Syelvia Putri , Heltina Desi
Published: November 2020

Corrosion is a degradation of metals quality caused by a chemical reaction between a metal and its ambient. The use of a green inhibitor is a natural method to control the corrosion rate of the metal. The objective of this research is to count the efficiency of the green inhibitor from biomass of tea and coffee extract, to find which variable that affect the most of corrosion rate of carbon steel, to determine the best concentration of extracts to control the corrosion rate of carbon steel. The extraction methods are the use method with a solvent ratio 1:4 of ethanol : aqua dest. Weight loss method is used to determine the rate of corrosion with 0,5g/L, 1g/L, and 1,5 g/L variance of inhibitor concentrations and 3, 6, 9, and 12 days immersed times. The lowest corrosion rate is 61,27 mpy at 1,5 g/l of tea extract inhibitor solution with 9 days immersed times and the highest efficiency is 79,02% at 1,5 g/l of tea extract inhibitor solution with 12 days of immersed times.
Analysis of Science Motivation Based on Learning of Conventional, Realistic and Hybrid Image In Chemistry
Authors: Rery Rusman , Copriady Jimmi , alimin Masnaini , wilda albeta Sri
Published: November 2020

Learning outcomes are a description of the development of student knowledge starting from the learning process to the end of the education program when students graduate. This study aims to analyse the differences in student scientific motivation from the aspects of self-efficacy, responsibility and student curiosity in learning chemistry (used a conventional, realistic and hybrid image). The sample of this research was 100 students from high school were surveyed in the Pekanbaru. This study used a science motivation questionnaire with variables of self-efficacy, responsibility and anxiety. The research data were analysed using SPSS by looking at the frequency with which students answered each item of questioner. The results showed that students had high motivation from the self-efficacy aspect. Students also have a sense of responsibility to learn well in the teaching and learning process. And have a high sense of anxiety
Application of Portable Soil Strength Probe on Bengkalis’ Peat
Authors: Yusa M , Koyama A , Yamamoto K , Sutikno S , Nasrul B , Fatnanta F , Fauzi M
Published: November 2020

Peat shear strength measurement in the laboratory is very challenging because undisturbed sampling of very soft peat is very difficult to get. Traditional in-situ test such as standard penetration test (SPT) and cone penetration test (CPT) on peat also have problems i.e. they are very heavy and the measurement is not sensitive on very soft peat. This study described the application of portable soil strength probe on peat. The tool can measure penetration resistance in term of stress and torsion in newton meter. Peat samplings and physical laboratory tests were also conducted. The location of the study is Bengkalis Regency, Riau Province. The result revealed that peat (up to 6-meter depth) at the location is mainly sapric, low ash content with water content more 1000%. Penetration resistance is predominantly 400 kPa. While shear test depicts that peat is mainly frictional with friction angle mainly between 17-21 degrees and very low cohesion i.e. 0.8-3kPa. This study revealed that fibre content correlate moderately with penetration resistance and shear strength. this preliminary work suggested that soil strength probe may be useful for peat characterization.
Development of Internet GIS Application of Traditional Tourism Village Koto Baru, South Solok, West Sumatra, Indonesia
Authors: Afnarius Surya , Akbar Fajril , Hasanah Zikriya , Ikhwan  , Putra Hafid Yoza
Published: November 2020

The halal tourism industry is rapidly developing and has become a current trend. It is a subcategory of tourism geared towards offering services that comply with Islamic principles for tourists. Indonesia has excellent potential for the development of this tourism industry because it is majorly populated with Muslims. For the first time, the country and Malaysia were ranked the world’s best halal tourist destinations in 2019. One of the oldest halal destinations in Indonesia is the Thousand Big Houses Area, in Koto Baru village, West Sumatra. However, due to limited information and technology, this area is less visited by tourists despite being hundreds of years old with the Minangkabau traditional building, which acts as a tourist attraction. Therefore, one of the solutions to help introduce this house to the world is developing an Internet Geographic Information System (GIS) for the village. This research aims to develop this application using the waterfall software development method. The application was programmed using PHP and Javascript, while its user interface was developed using the CSS Bootstrap framework. The results showed that the output was in accordance with the expectations that the app can be used to promote the village.
Potential of Secondary Metabolite from Marine Heterotrophic Bacteria against Pathogenic Bacteria in Aquaculture
Authors: Feliatra F , Mardalisa M , Setiadi J , Lukistyowaty I , Hutasoit A Y
Published: November 2020

Marine bacteria including heterotrophic bacteria are the most numerous organisms in nature and are capable of producing secondary metabolites. The secondary metabolite produced is a molecular compound produced from the secondary metabolic process, generally can be in the form of antibiotics, enzyme inhibitors, toxins, growth regulators, hormones, and insecticides. This study aims to examine the inhibitory ability of secondary metabolites of heterotrophic bacteria to the activity of pathogenic bacteria Aeromonas hydrophilla, Pseudomonas aeruginosa, and Vibrio alginolyticus. Around 10 heterotrophic bacterial isolates from the Marine Microbiology Laboratory collection, Fisheries and Marine Sciences Faculty, University of Riau was tested on pathogenic bacteria based on the Kirby-Bauer disk diffusion method. The results showed that all heterotrophic bacterial isolates were capable of inhibiting the growth of pathogenic bacteria such as A. hydrophilla (P), P. aeruginosa (Q), and V. alginolyticus (R). Vagococus fluvialis isolates are the best heterotrophic bacterial isolates in producing secondary metabolites compared to 9 other isolates. Where the clear zone formed is wider, that is 12.35 mm with the results of the activity test of 1877.78 mm2/ml. Based on the results, the heterotrophic bacteria are capable of producing secondary metabolites that inhibit the growth of pathogenic bacteria.
Development of Learning Flow for KPK Based on Interactive Multimedia Assisted RME Based on Students PGSD UNRI
Authors: Alim J A , Hermita N , Sari I K , Alpusari M , Sulastio A , Mulyani E A , Putra R A , Arnawa I M
Published: November 2020

This study develops a learning trajectory with the Realistic Mathematics Education (RME) approach which is assisted by interactive multimedia that are valid, practical, and effective for learning KPK topics on PGSD UNRI students in low-grade mathematics subjects. The research method used is design research (design research), which is characterized by a cyclical process of preparing for the experiment, conducting the experiment, and retrospective analysis. This research is focused on designing the learning flow, validating it, and then testing it one-to-one and in small groups. The revised learning flow is then implemented in the classroom. Research data were collected through observation, interviews, checklist, video taping, analysis of student work, and tests. The collected data is analyzed by quantitatively and qualitatively. From the research that has been carried out, the KPK learning flow has been generated in the valid students of PGSD UNRI in terms of RME state-of-the art, content and construction. In its implementation, the learning flow that is designed can work in accordance with what was hypothesized, so students can rediscover concepts in the KPK topic through horizontal and vertical processes of mathematical process. The resulting learning flow is also effective in improving students’ mathematical reasoning abilities.
The Effectiveness of Constructivism-based STEM Learning on Student Motivation and Learning Activity
Authors: Yustina
Published: November 2020

Research to examine students’ motivation and learning activities through constructivism-based STEM learning has been carried out from January to April 2020 at “SMP Purnama Pekanbaru”. The design of one group used a purposive sampling technique, that is class IX which chooses extracurricular biotechnology. Data collection used observation sheets of learning activities and questionnaire sheets about student learning motivation. Data of frequency and percentage is calculated and analyzed descriptively.The results show that learning biotechnology through the constructivism-based STEM approach is effective in increasing motivation and recycling activities of waste into fish pellets.
Identification of Misconceptions and Causes of Student Misconceptions on Genetics Concept with CRI Method
Authors: Gusmalini Amelia , Wulandari Sri , Zulfarina
Published: November 2020

This study aimed to identify students’ misconceptions and causes of students’ misconceptions on genetics concepts with Certainty Response Index (CRI). This research was conducted at Sains Tahfizh Islamic Center Senior High School in Siak with a sample is students’ of grade XII science program. Students’ misconceptions were identified by using 20 items multiple choices accompanied by CRI sheets with four scales of beliefs, which are very sure, sure, not sure, and very unsure. The causes of students’ misconception were identified using a students’ response questionnaire with three indicators of misconceptions causes, namely context, students’, and teachers. The data of students’ questionnaire were analyzed using a Likert-4 scale. The result showed 42.1% of students’ experienced misconceptions, 37.8% of students’ know the concepts, and 22.4% of students’ did not know the concepts. The cause of misconceptions in this research is in term of the genetic concept itself. This is evidenced by the result of students’ responses questionnaire analysis which showed an average of 79.6% students’ agreed that the scope of the context of genetics concepts is very broad and has difficult terms, so that it triggers students misconceptions.
Development of the PDEODE-WEB Model in Blended Learning to Improve the Students Critical Thinking Skills
Authors: Mailani T. , Zulfarina  , Syafii W.
Published: November 2020

The purpose of the study was to determine (1) the quality of the predict-discuss-explain-observe-discuss-explain-website (PDEODE-WEB) development in the blended learning of digestive system covered in valid aspects, (2) the impact of the PDEODE-WEB in blended learning on digestive system toward the critical thinking skill of high school students. Type of this research is a 4D that include Define, Design, Development, and Disseminate. Data analysis techniques that used are descriptive and inferential statistics using ANAVA tests. Research shows that (1) the results obtained from the PDEODE-WEB model in Blended Learning with tools, are empirically valid and reliable in learning, (2) the PDEODE-WEB model in Blended Learning has a significant influence on improving the thinking skills of SMA XI students at SMAN 4 Pekanbaru. This result is proven by the ANAVA test results with a Sig < 0.05. Then it can be concluded that there are improved thinking skills of students who learn to use PDEODE-WEB in Blended Learning. Therefore, the PDEODE-WEB model in Blended Learning can effectively improve the students' critical thinking skills on the digestive system material and found an average value of N-Gain of 0.6 with a moderate category.
Improving Critical Thinking Skills Of Senior High School Students Using The Problem Based Learning Model
Authors: Setiawan Heri Jaka , Islami Nur
Published: November 2020

The problem currently faced by physics teacher is the students are less skilled in developing their critical thinking skills. Students critical thinking skill can be improved by applying learning methods that require students to be more active during the learning activities. One method that can be used to improve students critical thinking skill is to use the Problem Based Learning model. This research used qualitative research methods. Qualitative research methods used to obtain a description and analysis of the problem to be researched. This research was conducted in class XII Science 1 of SMA Negeri 1 Rumbio Jaya. The steps that can be used to determine student’s mental activities in critical thinking solve a problem are identify, define, enumerate, analyze, list, and self-correct. The applying of Problem Based Learning models in the learning process in class has a real impact on improving students critical thinking skills.
The Need Analysis in the Development of Students’ Virtual STEM Project for Science Education
Authors: Hakim Lukman , Yennita Y , Zulirfan Z , Hermita Neni
Published: November 2020

The 21st century learning outcomes emphasize high-order thinking skills and information technology literacy. Using these skills, students can solve problems and think innovatively. Even though it has not been implemented optimally, STEM is a learning approach that is considered to be able to build high-level thinking skills of students. This study is an analysis phase in the development of virtual STEM for learning science. There were 52 respondents who participated in this survey. They are science teacher in Riau and Kepulauan Riau province. A questionnaire was used to identify the extent of respondents 'understanding about STEM and STEM implementation. The questionnaire also identified science teachers’ view of virtual STEM and the availability of computer facilities that support virtual STEM both at school and at students' homes. In this study, we found that some science teachers have already understood STEM but have not yet been implemented in their teaching. Especially for electrical circuit material, a virtual STEM project can be used as an alternative to overcome the problem of time constraints in running a project and is expected to improve the ability to think creatively.
Environmental Education in Grammar Learning Process for Junior High School students by using Multifunctional English Learning Media (MELDe)
Authors: Islami Annisa Permata
Published: November 2020

The teaching and learning process is no longer what it used to be. If the learning process is not adapted to the times, students will not be interested and the learning process will be ineffective, likewise with learning English in Indonesia, especially in grammar learning process. The inadequacy of learning media has decreased student enthusiasm and motivation in learning grammar. Previous researchers have relied primarily on one learning model without combining it with other models. This situation can actually lead the students’ tedium because there is no combination of several learning models. Therefore, this paper presents MELDe (Multifunctional English Learning Devices) as a smart solution to overcoming this problem. This research used Research and Development Methodology with 20 islamic junior high school students randomly in Pekanbaru as the samples. The research has distributed the questionnaire and MELDe learning media demo video via Google Form and Youtube to obtain the data needed. The data analysis technique used qualitative data in a descriptive form that described the practicality of MELDe. The practicality observation for MELDe, which used the ADDIE model, aimed to observe the practicality of this learning media as an English learning tool, especially on grammar material. All scores in the assessment aspect have been calculated and got an average score of 77.2% in the 'practical' category. Therefore, MELDe is stated to be ‘practical’ for junior high school students in learning English grammar and can be boosted up the enthusiasm of students in learning process.
Motivation and Skills of Science Teachers’ Online Teaching through Online Learning Training in The Covid-19 Period in Pekanbaru Indonesia
Authors: Taufik Hendra , Yustina
Published: November 2020

The purpose of this study was to analyze the motivation and skills of science teachers' online teaching through online teaching mentoring training in Pekanbaru in the month of May-July 2020. The subject of this descriptive study was the teachers participating in the training. Online training materials include Google classroom, Google form, slides, and videos. The training used the methods of simulation, training, modeling, and production of science teachers' online teaching videos. The research parameters were that five indicators of science teachers' online teaching motivation and ten indicators of skills from 4 aspects, namely the concept of online learning, implementation of Google classroom in learning, modeling of online learning, and online learning video products. Data collection instruments used the Google questionnaire form pretest-posttest and portfolio. Data is presented and analyzed descriptively. The results obtained the average value of teachers' online teaching motivation increased from a mean score of 67.2 (pretest) to 81.8 (posttest) with N-Gain 0.44, which is classified as effective. Teachers' online learning skills increased from a mean score of 55 (pretest) to 78 (posttest) with an N-Gain of 0.56, which is classified as effective. In conclusion, online teaching mentoring training is effective in increasing the motivation and online teaching skills of science teachers during the COVID-19 period in Pekanbaru.
Mathematics Teaching Videos with the Context of Riau Culture to Enhance the Mathematical Problem Solving Ability of Class VIII Students on the Material of Polyhedron
Authors: Yani Casmi Fitri , Murni Atma , Roza Yenita
Published: November 2020

This development research is based on low ability of students to solve mathematical problems (Mathematical Problem Solving Ability or MPSA) and the lack of learning devices which can be used as solution for these problems. This research was originally aimed at developing learning devices which is syllabus, lesson plans (LP), and student worksheet (SW). Due to the Covid-19 pandemic outbreak and online learning must be taken, the learning is supplemented with the preparation of learning videos. The development model used refers to the Borg & Gall model, but it has not gone through all phases. The phases that were completed: research and data collection; plan; development of initial product designs; first field trials; and product revisions. The following stages whose implementation requires formal classes cannot be performed. The resulting products are in the form of syllabus, lesson plans, student worksheet and math learning videos using the discovery learning model with Riau's cultural context on the Polyhedron material. Validity and practicability measurement was performed for syllabus, lesson plans, and student worksheets, while learning videos used directly. The results showed that the learning devices were categorized as valid and very practical for improving MPSA.
Learning Partial Differential Equations from Noisy Data using Neural Networks
Authors: Srivastava Kashvi , Ahlawat Mihir , Singh Jaskaran , Kumar Vivek
Published: November 2020

The problem of learning partial differential equations (PDEs) from given data is investigated here. Several algorithms have been developed for PDE learning from accurate data sets. These include using sparse optimization for approximating the coefficients of candidate terms in a general PDE model. In this work, the study is extended to spatiotemporal data sets with various noise levels. We compare the performance of conventional and novel methods for denoising the data. Different architectures of neural networks are used to denoise data and approximate derivatives. These methods are numerically tested on the linear convection-diffusion equation and the nonlinear convection-diffusion equation (Burgers’ equation). Results suggest that modification in the hidden units/hidden layers in the network architecture have an effect on the accuracy of approximations with a significant rate. This is a further improvement on the previously known denoising methods of finite differences, polynomial regression splines and single layer neural network.
Computational Implementation of Required Industrial Unit Operations for Bio-Plastic Production From Starch Extracted from Banana Peels by Aerobic Fermentation using Rizophus Oryzae
Authors: Bello A , Morales K , Sánchez L , Lidueñez V , Leal A , Gelves G
Published: November 2020

In this research computer modeling was performed with the SuperPro Designer Software to simulate the industrial-scale production of poly-lactic acid using the Rizophus oryzae fungus. The previous to predict the higher output of poly-lactic acid from different strategies: in the first study, a PLA production of 5.56 (kg/h) was obtained with an operating cost of USD 121,722,644/year. Based on the results, improvements were made to the process. The first alternative resulted in a PLA production of 43.64 (kg/h) with a total operating cost of USD 37,356,085/year. The second improved significant differences in terms of the most massive production of PLA was 64.97 (kg/h), with an annual operating cost of USD 55,334,811 being the most promising to be carried on an industrial scale.
Cinema Sound: Characteristics and 3D Acoustic Measurements
Authors: Tronchin L , Scaroni N
Published: November 2020

In 2014, an SMPTE report stated that sound consistency between dubbing stages and performance venues was not respected. SMPTE technical commission studied this issue in 3 commercial cinemas and 3 dubbing stages in Hollywood using the impulse response method. This lack in sound consistency is probably imputable to the use of a wrong calibration system (RTA + Pink Noise Method) that is time-blind and does not mimic the perceptual listening of the human being. A campaign of measurements has been conducted in Rome to test the acoustic properties of a dubbing stage room and a cinema performance room. Two measurement systems were implemented: One for the extraction of ISO 3382 parameters (Omni, Binaural, Soundfield) and one for studying the spatial distribution of sound in the room (EigenmikeTM).
Increasing the Solidity of Masonry Walls Made of Cellular Concrete Blocks of Autoclave Hardening by using Polyurethane Foam Adhesive Composition as a Masonry Solution
Authors: Dzhamuev B K
Published: November 2020

The article presents the results of experimental studies of determining the strength of normal adhesion (under axial tension) in the masonry of cellular concrete blocks of autoclave hardening classes for compressive strength B1.5 ÷ B3.5 on various cement solutions and polyurethane foam adhesives. Tests were carried out in the Laboratory of the Department of «Reinforced Concrete and Stone Structures» of Moscow State University of Civil Engineering on experimental samples representing two cubes of 150x150x150 mm in size, sawn out of cellular concrete blocks and bonded (glued) together using masonry (binding) compositions. The analysis of research results was performed and the value of the percentage of increase in normal adhesion in masonry when using polyurethane foam adhesives in masonry joints instead of cement masonry solutions was determined.
Random Forest for Human Daily Activity Recognition
Authors: Nurwulan Nurul Retno , Selamaj Gjergji
Published: November 2020

Machine learning classifiers are often used to evaluate the predicting accuracy of human activity recognition. This study aimed to evaluate the performance of random forest (RF) compared to other classifiers with considering the time taken to build the models. Human activity daily living data, namely walking, walking upstairs, walking downstairs, sitting, standing, and lying down were collected from smartphone-based accelerometer with sampling frequency of 50Hz. The dataset was evaluated using artificial neural network (ANN), k-nearest neighbors (KNN), linear discriminant analysis (LDA), naïve Bayes (NB), support vector machine (SVM), and random forest (RF). The results of the study showed that RF indeed predicted the activities with the highest accuracy. However, the time taken to build the models using RF was the second-longest after ANN.
Strengthening of Reinforced Concrete Beam Subjected to Shear Loading using Deep Embedment Method
Authors: Ridwan  , Dirar Samir , Jemaa Yaser , Kamaldi Alfian , Kurniawandy Alex
Published: November 2020

This research investigates the behaviour of non-engineered reinforced concrete (RC) beams strengthened with embedded steel bars. Two RC beams, namely control beam (Beam-A) and strengthened beam (Beam-B) were fabricated and tested under shear loading. Beam-B was strengthened with four 12 mm steel bars embedded in the core of the concrete beam. The results showed that Beam-A experienced shear failure while Beam-B failed in flexural tension where most cracks developed in the flexural span. The embedded steel bars were proven to shift failure mode from shear failure on Beam-A to flexural one on Beam-B. Furthermore, the shear capacity of the strengthened beam was enhanced by 31% compared to that of the control beam.
Molecular Weight of Liquid Natural Rubber (LNR) Product from the Chemical Depolymerization Process of High Molecular Weight Narutal Rubber Latex
Authors: Bahruddin  , Fadhillah Ivan , Septian  , Wiranata Arya , Zahrina Ida
Published: November 2020

The molecular weight of natural rubber varies greatly, from only a few hundred thousand to more than one million. Liquid natural rubber (LNR) products generally use natural rubber in the form of latex with a relatively low molecular weight, which ranges from a molecular weight of 600,000 g / mol. This study aims to determine the molecular weight of LNR products made from the chemical depolymerization process of natural rubber latex with a molecular weight of more than one million. The natural rubber used latex with 20% Dry Rubber Content (KKK). The natural rubber depolymerization process used NaNO2 and H2O2 degrading agents with a CoCl2 catalyst at 80 °C. H2O2 levels were kept constant at 1 parts per hundred rubber (phr), and NaNO2 levels vary at 0; 2; 3; and 4 phr. After the reactor temperature reaches 80°C, the CoCl2 catalyst was added, which level varied at 0; 1; 3; and 5 phr. The reaction time was varied, which 7, 8, and 9 hours. The results of LNR product was purified to form a semi-gel, and molecular weight was analyzed using gel permeable chromatography (GPC). The results showed that the lowest molecular weight of the resulting LNR product was 108,335 g / mol from the initial molecular weight of 1,384,638 g / mol.
Production of Cellulase and Xylanase from Eupenicillium Javanicum by Solid-State Fermentation Utilizing Pineapple Crown Leaves Waste as the Substrate
Authors: Evelyn  , Amraini S Z , Pratiwi E D , Ismala U N
Published: November 2020

Vast applications of cellulases and xylanases in many fields over the last few decades and high production cost demand extensive research in improving its quality and finding low cost substrates. These includes pulp and paper, food and feed, brewing, agriculture and biofuel industries. The main objective of this study was to investigate the use of pineapple crown leaves waste as the substrate to produce cellulases and xylanases in solid-state cultures (SSF) of Eupenicillium javanicum InaCC F154. Three SSF temperatures (25°C, 30°C and 35°C) and pH (4.0, 6.0 and 8.0) were tested for 96 h in solid media containing defatted soybean, (NH4)2SO4, NaNO3, CaCl2, and small amount of H2O. Then, its comparison with submerged fermentation (SmF) was also carried out. The SSF results showed that increasing temperature from 25°C to 35°C, increased the production of these enzymes. The pH also affected its activities, except at pH 4.0. The optimum pH and temperature for cellulase and xylanase production were found to be 6.0 and 35°C, respectively. The maximum cellulase obtained was 0.261 U/mL while much higher was obtained for xylanase with activity of 1.683 U/mL. SSF was better than SmF for xylanases (0.501 U/mL vs. 1.683 U/mL). The outcome of this study exhibits the potential of pineapple crown leaves as the substrate for xylanase production from E. javanicum by solid-state fermentation.
Multi-ethnic Settlement Concept in Denpasar City, Bali, Indonesia
Authors: Agustian Endy , Rachmawati Rini , Rijanta R. , Pitoyo Agus Joko
Published: November 2020

Kampung Islam Kepaon settlement is a portrait of Islamic-based community settlements in Denpasar city, Bali with the values of traditions, customs, culture, and traditions of Islamic ancestral heritage in the middle of the Balinese who are Hindus. The characteristics of the Islamic community are provided by cultural acculturation, which is the key to harmony and connecting in establishing relationships with the surrounding community who are Hindus. This research objective is to reveal a multi-ethnic settlement concept in the Kampung Islam Kepaon settlement which is based on the phenomenon of the community in the Kampung Islam Kepoan settlement. The research method used in this research is a qualitative method and when it is carried out is based on natural conditions, as well as with less patterned and specific research. The data found can be interpreted to reveal a variety of uniqueness, describe, understand the meaning of a particular social and can be justified scientifically as a result of the research. The results show that the Kampung Islam Kepaon settlement concept is based on Islamic values which have contributed greatly to every aspect of society, such as the physical aspects of settlements, economic aspects, socio-cultural aspects, and basic values of life aspects.
Community Preparedness on Transboundary Oil Spill Governance in Bintan Island
Authors: Akbar Dhani , Setiawan Azhari , Prayuda Rendi , Putra Ardi , Aznor Ariski , Yudiatmaja Wayu Eko
Published: November 2020

The waters of the Kepulauan Riau have a strategic position, the entry and exit point of the Malacca Strait and connecting Middle Eastern which known as oil producer countries regions and East Asian Industrial countries. The main role to guard the environment and implement the government policies is the local community in the border area. This study applied quantitative method to investigate public perceptions towards oil waste-related issues by identifying knowledge, attitude, perception about impact and future condition foreseeing, attribution of responsibility, political perception, and political attitudes. KMO Measure of Sampling value is greater than. 5 (KMO = .672) and indicates the research instrument was meritorious and statistically significant (<.001). In term of political perception and attitude, we found a high positive correlation (Pearson’s R=.700, p=<.001) between the two variables. High score in attribution of responsibility to TNI indicates a potential further analysis on behalf of securitization theory from Copenhagen School of International Security and International Relations. Respondents tend to believe and demand that security sector must take a major role within the issues since a normal political process was perceived to be not quite enough to overcome the problems. It means that securitization will be perceived to succeed in the bilateral or trilateral framework instead of multilateral one.
Study of Groundwater Pathway in the Shallow Bedrock Area using Very Low Frequency Method
Authors: Islami Nur , Juandi Muhammad
Published: November 2020

In the hard rock and thick forest area, the use of active geophysical method for groundwater exploration is relatively difficult. In this study, very low frequency survey method has been successfully used to explore the possibility of the groundwater pathway in the hard rock area. The very low frequency method used T-VLF with the reding stations of 2 m and 5 m. The data then processed using inhouse software. As the results, the VLF model shows the conductive zones at several sites that are observed at the depth of less than 10 m. These conductive zones are indicating as the zone of water pathway. The study area is dominated by the non-conductive zone which is indicating that there is no possibility of water pathway. Generally, the water pathway has been found between the hot spring and small lake at the southeast of the study area.
Preparation and Characterization Activated Carbon Based on Mesocarp of Bintaro Fruit as Electrode Materials Supercapacitor Cell Application
Authors: Farma Rakhmawati , Siagian Wellny Fransisca , Taer Erman , Awitdrus
Published: November 2020

Supercapacitor is an energy storage device that has high energy and power density. One of the main component in supercapacitor cells is electrode. A production of activated carbon made from mesocarp of Bintaro fruit as a supercapacitor cell electrode has been successfully. Activated carbon electrodes were prepared through a pre-carbonization process, chemical with KOH 0.5 M activator, carbonization process using N2 gas and physical activation using CO2 gas. In this study, the physical activation process was carried out with temperature variations of 650°C, 750°C, 850°C and 950°C which of KAMBB-650, KAMBB-750, KAMBB-850 and KAMBB-950 respectively. Microstructure analysis shows amorphous structure for the carbon electrodes which is by the presence of peaks at an angel of 2θ around 24° and 44°. The increasing physical activation cause smaller Lchigh specific capacitance. In this study, the optimum temperature obtained in 850°C of KAMBB-850 sample. High specific capacitance as high as 267,6 F/g was found on KAMBB-850. The lowest capacitance obtained at carbonization temperature 950°C of KAMBB-650 sample with specific capacitance as high as 71,4 F/g.
Liquid argon photodetection systems for neutrino detectors: A minireview
Authors: Delgado M , Gutiérrez R M , Fuentes F
Published: November 2020

A growing number of experiments with particle detectors using liquid argon are currently being carried out, as this is an excellent means of detecting neutrinos. These experiments develop different capture and measurement systems of the photons generated by the excitation of the argon atoms when a charged particle passes. New low-cost technologies, more sensitive and efficient detection methods, hardware and electronics, optimize and take advantage of the characteristics of the processes involved. This minireview presents the main characteristics of photodetection systems used in some of the most important experiments for the finding of neutrinos, particularly those that use liquid argon at cryogenic temperatures (-186 °C), such as Deep Underground Neutrino Experiment and the Micro Booster Neutrino Experiment. In addition, this article presents a comparison of the advances of each cryogenic photodetection system with the aim of promoting the use of this technology in new research fields.
Rice husk incidence on the physical, thermal and mechanical properties of H10 block from San José de Cúcuta, Colombia
Authors: Colmenares-Uribe A P , Sánchez-Molina J , Díaz-Fuentes C X
Published: November 2020

The generation of new building materials responds to the reduction of energy consumption and regulation of building interior temperatures as strategy to improve energy efficiency in materials engineering and architecture. This research focuses on the study of the rice husk incidence on the physical, mechanical and thermal properties of H10 block manufactured in the metropolitan area of San José de Cúcuta, Colombia. The methodology consists in 4 stages: In first instance, raw material characterization to identify chemical, structural and morphological components of clay and rice husk. Then, H10 blocks manufacturing in 2 clay mixtures, fired at 900 °C, 1000 °C and 1100 °C. Likewise, tests of manufactured samples to analyze its physical and mechanical properties. Parallel to the manufacturing process, transfer and heat fluxes simulations to evaluate surface temperatures and energy concentration of H10 block. In conclusion, rice husk acts as a technological nutrient added to clay mixture and strengthens thermal and insulating capacity of blocks. Nevertheless, the presence of rice husk in clay mixtures increases water absorption capacity of the products, as the percentage of husk increases. And therefore, the compressive strength decreases, which is a factor to consider for the constructive application of H10 block.
Biodegradable thermosets polymers as an alternative solution to pollution generated by plastics
Authors: Paipa-Álvarez H O , Palacios Alvarado W , Medina Delgado B
Published: November 2020

In this research work, a description was made of thermoset polymer materials and their relationship with the environment. The traditional thermoset manufacturing processes make their recycling and reuse complicated. Consequently, most products made with this type of material end up accumulating in landfills and their disposal generates a high environmental impact. This is why a description of thermoset and biodegradable polymers is made to identify the differences between them and the advantages of biodegradable materials. This being so, it is found that the scientific community presents as a proposal or alternative solution to this environmental problem the development of new methodologies and technologies to synthesize families of thermoset biodegradable materials, as for example the case of “glycix”, “titan” and “hydro”, and that from capital investment in science and technology processes in the area of materials engineering, by the productive sector and Universities of countries such as for example; Mexico and Argentina, managed to develop on an industrial scale biodegradable resins that can be processed by all conventional plastic molding methods and significantly reduce the carbon footprint.
Impact of the inquiry based-science methodology on learning physics
Authors: Rodríguez H D , Gamboa-Suárez A A , Avendaño-Castro W R
Published: November 2020

The stigmatization of natural sciences and mathematics as difficult, boring and non-practical subjects, starting at the secondary levels, has caused an increased disarticulation between the significant learning of physics and the student, this can be reflected in a less development of basic competences, an almost instinctive revulsion of a large number of students towards these subjects and poor results in the tests that are carried out. Reflecting on this situation, we apply the inquiry-based science education. The intervention was carried out in a private calendar B school in the town of Chía, Colombia; Latitude: 4.85, Longitude: -74.05 4° 51′ 0″. The participants were 80 students, the instruments used to collect the information were: class observations, surveys, interviews, an entrance, an exit test and another after the exit test. Two specific inquiry based-science type activities were designed: laboratory practices and the manufacture of a device by the student. These two activities in turn had matrices with defined evaluation criteria to evaluate the impact of the intervention. The students found in the investigation, a much more conducive environment for their learning and in the end the proposal allowed to identify positive impacts of the inquiry based-science as well as not so desired results.