bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of CPS-Based Assessment Instrument for Critical Thinking Ability in Stoichiometry
Authors: Agustini  , Rery Usman , Anwar Lenny 
Published: November 2020

Abstract
The purpose of this study was to determine the characteristics (validity, reliability, difficulty indices and discrimination indices) of the items in the developed assessment instruments. Subjects in the study were 30 students of class X Science 1 SMA Negeri 2 Bantan. The samples in this study were chosen by purposive sampling technique, in which the samples were selected based on the researchers’ consideration. Then, the approach used to develop the assessment instrument was Research and Development (R&D) adapting Borg & Gall Model. In this study, the feasibility test was carried out to see the construct validity, reliability, difficulty indices, and discrimination indices of the instrument. The CPS-based assessment instrument for critical thinking ability on Stoichiometry was developed in the form of essay questions. This instrument produced 10 items that were declared valid and reliable with a reliability value of 0.749. Thus, this study concluded that CPS-based assessment instrument for critical thinking ability provided more comprehensive information about the characteristics of the instruments that have been developed.
The Development of Schoology as Media to Supporting Blended Learning on Stoichiometry Topic
Authors: Linda Roza , Anggraini Citra , Abdullah  
Published: November 2020

Abstract
This study aims to develop Schoology media as a support for Blended Learning on the subject of Stoichiometry. This research used a Research and Development (R&D) design with the Plomp model. The Plomp models have four steps faces (investigation, Design, construction and validation). The data was collected used an instruments in the form of validation sheets given to four validators and response sheets to two chemistry subject teachers and 20 students in Senior High school. The data was analyzed by calculating the percentage of the validation score and the user's response. The results obtained that the Schoology learning media are valid with an average score 93.98%, while, the teachers responded when they used the media learning was very good with the percentage of response scores 94.32% and the average student response score of 85.15 %. Based on the results of the study, it can be concluded that the Schoology media as a support for Blended Learning on the subject of developed stoichiometry is declared valid.
Readiness in Teaching Science: Early Childhood Education Teacher’s Online Experience
Authors: Novianti Ria , Puspitasari Enda , Solfiah Yeni , Febrialismanto  , Maria Ilga , Garzia Meyke 
Published: November 2020

Abstract
This research provides an overview of early childhood education teacher’s readiness in teaching science online during Covid-19 pandemic. This research uses descriptive quantitative method with 159 early childhood education teachers as the subject. Questionnaire designed based on holistic model of learning readiness that consist of three indicators, emotive-attitudinal readiness, cognitive readiness, and behavior readiness. The sampling technique used is simple random sampling. Data analysis techniques are present in a percentage form. The overall of early childhood education teacher’ readiness in designing science online learning in ready category.
Application of Soil Resistivity Testing using Geoelectrical Method For Landslide Identification
Authors: Ervianto Edy , Marpaung Noveri Lysbetti , Amri Rahyul , Azzmi Amirul Latief 
Published: November 2020

Abstract
Vulnerable area is an area whereas landslide materials move. One of avalanche causes is slip surface or shear surface. Geoelectrical Method is measuring potential different of voltage and current caused with electrical current injection into ground through a pair of current electrodes. Potential different is measured through a pair of potential electrodes.This study aims to calculate Resistivity-Values from underground soil layer, so it is used to get soil resistivity map and determine whether an area/road is susceptible for landslide by using Dipole-Dipole Configuration in Geoelectrical Method and Res2Dinv-Software. This research is conducted in Muara Lembu Village, Riau Province as far as 80 meters from both sides of road. Each value of Soil Resistivity can be represented with certain colour of Natural Material. Resistivity-Values from Top Soil at 0.854m–4.62m depths upto Lowest Layer at 11.8m–17.9m depths are smaller. Resistivity-Value from Trajectory-I Top Soil is H>328.5Ωm, whereas A<15.85Ωm Lowest Soil Layer, whereas Trajectory-II Top Soil is H>350.5Ωm and A<21.05Ωm Lowest Layer. Resistivity-Values from both sides of road can be different but Natural Material form them are same. As conclusion, Top Layer upto Lowest Layer of Trajectory-I and Trajectory-II are in Middle-Conductor Range, means these areas are susceptible for landslide.
Simulating of Microbial Growth Scale Up in a Stirred Tank Bioreactor for Aerobic Processes using Computational Fluid Dynamics
Authors: Hernandez S , Niño L , Gelves G 
Published: November 2020

Abstract
In this paper, the effects of some empirical scale up criteria (Reynold's number and Impeller power per bioreactor volume) on gas-liquid mass transfer and microbial growth rates are analyzed using computational fluid dynamics simulations in a stirred tank bioreactor. The effects of turbulence, fluid flow and bubbles dynamics were simulated by using a two equation turbulence model, a multiple reference frame and a population balance, respectively. The impeller power per bioreactor volume scale up criterion showed better microbial growth rates than Reynold's number scale up criterion. However, high cellular damage due to turbulence in animal cell culturing are still challenges in large scale up bioreactor prototyping.
Tempeh Extract Protects HepG2 Cells Against Oxidative Stress-Induced Cell Death
Authors: Surya Reggie , Romulo Andreas 
Published: November 2020

AbstractTempeh is an Indonesian fermented traditional food made from soybeans inoculated withRhizopus oryzaeand/orRhizopus oligosporus.It exerts antioxidant activities mainly due to the presence of bioactive compounds known as isoflavones. We previously observed that tempeh ethanol extract increased the basal expression of some cellular antioxidant enzymes including catalase and superoxide dismutases in HepG2 cellsin vitro.In this study, we showed that pretreament with tempeh extract protected HepG2 cells from oxidative stress triggered by TBHP (tert-butyl hydroperoxide) by reducing cellular ROS (reactive oxygen species) generation, TBARS (thiobarbituric acid reactive species) levels, caspase-3 activity and eventually cell death. We hypothesize that the resistance of cells pretreated with tempeh extract towards the toxicity of TBHP was in part due to the upregulation of cellular antioxidant enzymes. Taken together, our findings highlight the antioxidative potentials of tempeh, particularly in an attempt to develop tempeh as a functional food offering health-related benefits to humans.
Performance of TiO2/Graphene (cocoPAS) Composite as Photocatalyst for Removal of Phenols in Aqueous Solution
Authors: Heltina D , Ulfa F , Komalasari  
Published: November 2020

Abstract
As one of the hazardous industrial wastes, an excessive amount of phenol in the environment can cause damage to the biological ecosystem and nutrient cycle. Phenol removal can be done by photocatalysis process using photocatalyst materials such as titanium dioxide (TiO2). The photocatalysis activity of TiO2 can be improved by making TiO2-graphene (cocoPAS) composite. The obtained TiO2-graphene (cocoPAS) composite was characterized by Scanning Electron Miscroscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared absorption spectroscopy (FTIR), and Breneur Emmet Teller (BET). The performance of the TiO2-graphene (cocoPAS) composite in phenol degradation was tested in a photocatalysis process with variation are the concentration of phenol (10, 20, and 30 ppm, respectively) and photocatalysis temperature (30, 40, and 50 °C, respectively). TiO2 particle loaded on the graphene sheet and Ti-O-C bond was formed at 719 cm−1. The size of anatase and rutile crystals are 26.39 nm and 27.39 nm with the fraction of anatase and rutile are 57% and 43%. The surface area of the TiO2-graphene (cocoPAS) composite is 40.9 m2/g. The highest efficiency of phenol degradation was achieved when the concentration of phenol is 10 ppm and photocatalysis temperature is 50°C which efficiency of phenol degradation is 96.9%. The higher concentration of phenol will decrease the efficiency of degradation but the degradation efficiency of phenol increases with an increase in photocatalysis temperature.
Utilization of Dairy Industry Wastewater for Nutrition of Microalgae Chlorella vulgaris
Authors: Handayani Titin , Mulyanto Adi , Priyanto Fajar Eko , Nugroho Rudi 
Published: November 2020

Abstract
This experiment utilized dairy industry wastewater, which is located in Sukabumi, West Java, Indonesia. The aim of this experiment was to evaluate the biomass production and dairy wastewater treatment using Chlorella vulgaris. The experiment lasted for 6 months (July – December 2019). Monthly water analyses for a variety of physical-chemical factors were also investigated. Microalgae were cultivated in a 10 m3 raceway bioreactor type. The results indicated that a decrease in the concentration chemical substances of the wastewater, namely 74% N-amonia, 77% total nitrogen (TN), 78% total phosphate (TP), 92% Chemical Oxygen Demand (COD), and 77% Biological Oxygen Demand (BOD) within 10 days of the process. A maximum of 1.2 g/L dry biomass was obtained in 18 days. The percentage lipid content was determined by soxhlet extraction and was shown to be 25%. To sustain the growth of microalgae, it was necessary giving 3.5 mg NPK/L on the tenth day and then continuously added.
Preliminary Investigation of Geothermal Potential in Pawam Site, Rokan Hulu, Indonesia
Authors: Febriani Riski , Islami Nur , Muhammad Juandi 
Published: November 2020

Abstract
The site of research area is located in the back arc basin of Sumatra. It has the potential for the hot springs. This research used a Dipole-dipole array of geoelectrical resistivity method. The length of the survey line varies due to in the research location there are many buildings that become tourist attractions. The results showed that the subsurface structure consisted of silt, sandstone and meta sediment. The resistivity distribution shown that there was found the silt layer of soft wet mud in the hot spring zone. The distribution pattern of hot spring in this site is an overflow flow type. The flow is controlled by a fault zone. The direction of this flow is west of the river flow.
Traffic Noise Model for Urban Area Study Case Pekanbaru City
Authors: Hasan Indra , Erwin  , Zulkarnaini  , Isranuri Ikhansyah , Junaidi Abdul Khair 
Published: November 2020

Abstract
Traffic noise is a major problem in urban area that becoming complicated environment issues. The traffic noise has different characters in each of main road due to different size and weight of vehicles that go through the road in which resulted different noise intensity. In this study, the noise traffic measurement was conducted to get the data. The purpose of this study is to present the traffic noise model which compared to the actual traffic noise level that resulted from vehicle flow on the roads. The two models of predictive noise traffic have the similarities to the actual noise traffic.
World Wide Fund for Nature (WWF) Attempt to Resolve Environmental Damage in Kampar River Basin, Riau (Case Study: Koto Panjang Hydroelectric Power Plant)
Authors: Harto Syafri , Habibie Dedi Kusuma , Amri Khairul , Akbar Fachrul Reza 
Published: November 2020

Abstract
This study aims to investigate the World Wide Fund for Nature (WWF) attempt to resolve environmental damage in the Kampar river basin, Koto Panjang hydroelectric power plant, Riau. Various problems related to the function of the river basin that has changed in the long term will hinder the sustainability of community life and damage the environment. This study used qualitative research methods with a descriptive-analytic approach. Interview and observation were used as data collection techniques to see how WWF's role in resolve environmental damage in the Kampar river basin. This research reveals WWF's role in protecting the environment and empowering communities through the use of river basins, such as Forest and Land Rehabilitation run by local communities, Ecosystem Approach of Aquaculture (EAA) application as sustainable aquaculture management, and community empowerment through processed fish products
Composition Modification of Iron Oxide Particles Using Activated Carbon for Adsorbtion of Cooper-Polluted Water From Siak River Water Pekanbaru, Riau
Authors: Mardhatillah Wirdati , Amiruddin Erwin , Taer Erman 
Published: November 2020

Abstract
Modification of magnetite (Fe3O4) nanoparticles with activated carbon of Pulai leaveshas been carried out. Magnetite (Fe3O4) nanoparticles were synthesized from natural sand of Padang beach West Sumatra and activated carbon was extracted from Pulai leaves. Structural and morphological properties of magnetite nanoparticles were studied using X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM) respectively. Elemental composition of the samples was identified using X-Ray Fluorescence Spectroscopy (XRF). The heavy metal (cooper) adsorption was determined using Ultra Violet Visible light Spectroscopy (UV-Vis). The ability of magnetite(Fe3O4) nanoparticles modified with activated carbon for adsorbing the cooper ion in Siak river water is discussed.The results indicate that magnetite (Fe3O4) nanoparticlesmodified with activated carbon of Pulai leavescan absorb heavy metal Cu contained in Siak river water.
Bamboo-Based Activated Carbon as Binder-Free Electrode of Supercapacitor Application
Authors: Taer Erman , Sihombing Martauli , Taslim Rika , Agustino  , Apriwandi  
Published: November 2020

Abstract
Activated carbon has been an ideal material for supercapacitor electrodes. Its extensive used due to abundant, renewable, and cost-effective production. In this work, we developed activated carbon monolith materials through carbonizing bamboo stems wastes and treating them with ZnCl2 in high-temperature pyrolysis as binder-free electrode of supercapacitor application. ZnCl2 impregnation carried out in one-step, two-step, and three-step. Different steps of ZnCl2 impregnation were employed to evaluate the activated carbon preparation variables including one-step, two-step, and three-step. The reduction of monolith dimensions has been reviewed as physical properties. Furthermore, the symmetric supercapacitor was performed with cyclic voltammetry in sandwich-type at 1 M H2SO4. In addition, the thicknesses of electrode carbon monoliths were varied such as 0.1 mm, 0.2 mm, and 0.3 mm. The one-step ZnCl2 impregnation in 0.1 mm thickness of carbon monolith were exhibit best electrochemical performance with highest specific capacitance of 145 F g−1 and followed by two-step and three-step impregnation as high as 132 F g−1 and 131 F g−1 in low scan rate of 1 mV s−1, respectively. These results demonstrate that the bamboo stem-based activated carbon monolith materials are promising as binder-free electrode for supercapacitor energy storage.
Mathematical analysis of physical stability in the design of bipolar amplifiers through a computer tool
Authors: Ramírez-Carvajal L , Puerto-López K , Ramírez-Mateus J 
Published: November 2020

AbstractThis article presents a computer tool that allows to carry out a mathematical analysis of the physical stability of the bipolar transistor in the design of amplifiers. The tool allows to introduce the values of voltage gain, output impedance and input impedance, current gain of transistors and power supplies, to give as a result the values of the resistances. It also allows modifying the transistor operating point and graphing in real time the behavior of the load line and the output signal of the amplifier. Different designs were made with the tool and the results obtained were compared with academic software approved by the scientific community. The errors in all variables evaluated were less than 1.5%. The results are important for semiconductor physics, taking into account that they reaffirmed the directly proportional relationship between the stability of the transistor in its amplification state and the power required to operate. Finally, we conclude that the computer tool allows us to design amplifiers with bipolar transistors with precision and, depending on the need or application of the amplifier, the operating point Q is located in the load line to obtain an output signal without distortion and with the least power dissipation.
Estimation of the energy contributions of a hydroelectric power station using space parameter exploration
Authors: Mesa F , Devia D M , Ospina R 
Published: November 2020

Abstract
From the study of nonlinear dynamics, the study of chaotic dynamics in deterministic systems has been developed. If a system is deterministic, its behavior would be easy to predict. However, there are systems in which their behavior seems to be unpredictable due to the complexity of the dynamics of the system, which is reflected in an aperiodic behavior. This article presents the application of parameter exploration techniques for the study of aperiodic deterministic systems using time constraint estimation through the calculation of the Lyapunov exponent in order to estimate future system values. This technique is developed on a part of the energy matrix of the Colombian system, especially with hydroelectric production.
Developmental perspectives of numerical thinking for the interpretation of physical quantities
Authors: Valbuena O , Salazar-Torres J , Diaz J A , Rincón-Leal O , Bravo A 
Published: November 2020

Abstract
This research reveals the perspectives in the teaching of numerical thinking through a documentary review. The representation of physical elements such as functions, vectors and operators, and their subsequent interpretation through numerical thinking gives meaning to the physical quantities that such elements represent. A documentary sample integrated for 40 sources on numerical thinking such as articles published in indexed journals, postgraduate dissertations, and books is considered. A qualitative content analysis method is used. First, an encoding procedure is applied for tagging the extracted information from the source documents. Then, a split and merge procedure is considered in order to establish from the tags the dimensions and categories that allow determining the conceptual relationships that support the developmental perspectives of numerical thinking. The method reveals that the numerical thinking can be developed in the global context from four perspectives, namely, historical, theoretical, curricular, and social perspectives. From these results, an incorporation of the such perspectives can be institutionalized for promoting curricular, didactic and evaluative new proposals for numerical thinking teaching.
Conceptual computation in artificial mathematical intelligence as a paradigm-shifting technique in physics and mathematics
Authors: Gómez-Ramírez D A J , Herrera-Jaramillo Y A 
Published: November 2020

Abstract
We describe in a very concise way the multidisciplinary program of artificial mathematical intelligence and the need of a new and improved paradigm of formal computation based on conceptual generation, called conceptual computation, with the potential of being a global paradigm-shifting technique in theoretical physics and computational mathematics. Furthermore, we describe some of the most outstanding results regarding fundamental cognitive abilities needed for the materialization of conceptual computation such as analogical reasoning, metaphorical thinking and conceptual blending. Finally, we present a concrete example of the conceptual computation of the notion of binary continuous operation as a formal blend (i.e. many-sorted first order categorical colimit (pushout)) of the notions of continuous function between topological spaces and perfect square topological space.
Lateral interaction of local geosystems of outwash valley landscapes of the Lower Vyatka
Authors: Matushkin A S , Prokashev A M 
Published: November 2020

Abstract
The paper presents the results of the analysis of lateral interaction of outwash valley landscapes on mesorelief slopes in various parts of the Medvedsky Pine Forest Nature Sanctuary in the lower Vyatka valley. The baseline data were the results of the authors’ field and laboratory analytical studies of more than 120 landscape facies. These elementary landscapes occupy various geomorphological stages in the relief: I, II and III terraces above the floodplain as well as a strip of alluvial glaciofluvial deposits which graduates to the slope of the river valley. The mesorelief within each of these stages is also heterogeneous: it includes aeolian dunes and knobs, interdunal and interknob basins, karst basins and sub-horizontal surfaces. Three models of slope geosystems of the outwash valley are presented: ancient aeolian, marsh and karst. An original method for evaluating the strength of lateral interaction between certain units of slope geosystems based on the degree of difference in their states is proposed.
Rationale for the production of hard-to-recover deposits in carbonate reservoirs
Authors: Mukhametshin V Sh 
Published: November 2020

Abstract
Based on the study towards oil recovery by deposits in the carbonate reservoirs of the Volga-Ural oil and gas province of Kashiro-Podolsk age, an express method is proposed for estimating recoverable oil reserves and service life through the parameters that can be determined at the stage of geological exploration with a sufficient degree of precision. As a follow-up to a series of feasibility studies, the method provides a rationale for the need to stimulate the production of similar deposits with hard-to-recover reserves.
Designing measures to increase oil recovery based on the identification and grouping of deposits
Authors: Mukhametshin V S , Andreev V E , Yaskin S A 
Published: November 2020

Abstract
The article provides a grouping of development objects using the method of the main components of the fields developed by the Langepasneftegaz TPP and identifies landfill sites. Based on the geological and field analysis, a set of measures has been substantiated to increase the efficiency of development of objects in four groups. The identified patterns allow us to make informed technological decisions aimed at increasing oil recovery, reducing water inflow and increasing the efficiency of the facilities development, taking into account the peculiarities of the geological structure of the deposits.
Determination of the gas factor of oil at Western Siberia fields
Authors: Almukhametova E M , Mikhaylov M O , Stepanova R R 
Published: November 2020

Abstract
The article presents the results of applying the method for determining gas factors at the wellhead of the support network of wells and separation sites of LUKOIL-Western Siberia LLC. The object is systems of oil separation and treatment, collection and transportation of gas from fields developed by LUKOIL-Western Siberia LLC. The aim is to measure the amount of gas produced together with oil, and specify gas factors by fields. The article describes and analyzes the existing oil treatment systems and gas collection and transportation systems. The tie-in points for field measurements of gas consumption have been determined. Instrumental field measurements of gas consumption in pipelines at all separation facilities and laboratory studies of properties and composition of gas were conducted. The relevance of the research is due to the increasing attention to the rational use, reduction of losses and an increase in the overall level of use of gas extracted from the subsoil