bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of temperature variation on the fluctuation of a sessile bubble rising in a stagnant medium
Authors: Faik A M E D , Mohammed A A 
Published: February 2021

Abstract
The present work represents an experimental investigation of the flow dynamics and features of a rising isolated bubble within a stagnant water column under variable temperature. The experimental tests have been carried out using high speed imaging with backlighting. Five different values of the water temperature (namely 10, 20, 30, 40, and 50°C) have been implemented during the experiments. The studied features are the bubble size (diameter and circumference), bubble shape (sphericity and aspect ratio), bubble rising velocity, in addition to the bubble zigzag motion features (angle, maximum horizontal diameter, velocity, and occurrence time portion). The obtained results showed that as the temperature increases, the degree of bubble zigzag motion from its vertical path increases, which means the flow of the bubble becomes less stable. Bubble diameter is shown to be irresponsive to temperature for small value increase, whereas, for greater temperature magnitudes (from 30 to 50°C) it is shown to be proportional. All other features are shown to be proportional to temperature variation. The zigzag motion features are also shown to be proportional to water temperature variation except the average occurrence time is inversely proportional to this change.
Practically Examining the Effect of Thermal Loads on Curved Tubes Made of Different Natural Composite Materials
Authors: Jassim Riyadh Fakher , Abdulla Fadhel Abbas 
Published: February 2021

Abstract
This paper examines the effect of changing temperature on the curved natural composite material pipe (Walnut husks powder with polyester) and curvature angle θ= 34° practically. This work involves the design and fabricates of curved pipe samples with an angle of curvature θ=34° at 50 % weight fraction. Also, tensile and thermo-mechanical test were performing to find the mechanical properties of the specimens. Experimental work included design and manufacturing test rig to simulate thermal stress. The experimental results revealed that a maximum hoop strain and longitudinal strain increased with increasing the temperature. The hoop stresses at crown and intrados positions were more than the hoop stress at extrados position by 150.762% and 138.363% respectively, and the von mises stresses at crown and intrados positions were more than the von mises stress at extrados position by 218.259% and 178.193% respectively. In the curved pipe, the hoop strains at intrados and crown positions were more than the hoop strain at extrados position by 114.583% and 60.416% respectively.
Evaluate the Performance of Jalan Otista Bandung with on-Street Parking
Authors: Fadriani Hetty , Afiyah Salamatul , Liklikwatil Yakob , Haris Samun , Hidayat Iman , Hidayat Rahmad 
Published: February 2021

Abstract
Road performance is the ability of a road to serve traffic flow which can be determined by its capacity, free-flow speed, and degree of saturation. The performance problem of Jalan Otto Iskandar Dinata (Otista) Bandung, which is located in an office and trade area, occurs due to high side activity, namely on-street parking marked by congestion. Analysis conducted using the Indonesian Road Capacity Guidelines (PKJI 2014) to the traffic data collected on weekdays and weekends. This research tries to find a solution by eliminated on-street parking. The existing condition shows the volume on weekend at noon at 3242 pcu/hr, side friction is classified as very high with the proportion of on-street parking at 76%, spoot speed of 12 km/hr, the free flow speed of 36.89 km/hr, a capacity that occurs is 3324 pcu/hr, and degree of saturation is 0.98 with the level of service E. The road performance improvement scenario is carried out by setting on-street parking which gives the free flow speed value greater than the existing condition, class of side friction becomes very low, increased capacity, degree of saturation below 0.85 as determined by PKJI 2014 by improving the level of service to C.
Transmission Coefficient Testing on Sweatbatching Model with Artificial Reef Brick-1 Armor
Authors: Mahardika Andrew Ghea , Ramady Givy Devira 
Published: February 2021

Abstract
In Indonesia, planning ocean breakwater (breakwater) has not been done because of the expensive construction costs, while Indonesia is a country that has the fourth-longest coastline in the world and there are plenty of beaches due to damage from waves. This issue is of interest to researchers for study. The purpose of this study was to determine the characteristics of the wave transmission coefficient when using an armor breakwater sink with a brick-first artificial reef. Tests on laboratory models and multiple linear regression analysis methods are used to look at some of the variables expected to affect the size of the transmission coefficient (Kt). Of the model used the results showed that the wave comes (Hi), height (h), and width of the structure (b) of the breakwater, the water surface distance (F) with the breakwater where all variables are divided by gT2, significantly influence the transmission coefficient.
Anti Fuzzy Line Graphs
Authors: Nusantara Toto , Rahmadani Desi , Asmianto  , Trisanti Yuliana , Bin Gani Abdullah 
Published: February 2021

Abstract
In crisp graphs, if a graph G is given then we can define line graph L(G) of it. In a similar way, for a given fuzzy graph, we can determine its fuzzy line graph. A number of important results about fuzzy line graphs have been obtained. However, study of anti fuzzy line graphs is still open. Motivated by this, we are interested in studying anti fuzzy line graphs. In this paper, we define the concept of anti fuzzy line graphs. We derive a necessary and sufficient condition for an anti fuzzy graph to be isomorphic to its corresponding anti fuzzy line graph. We investigate when an isomorphism between two anti fuzzy graphs follows from an isomorphism of their corresponding anti fuzzy line graphs. We conjecture a necessary and sufficient condition for an anti fuzzy graph to be the anti fuzzy line graph of some anti fuzzy graph. In particular, we give some result related to regular anti fuzzy line graphs.
DNA Amplification of Methanogenic Bacteria from The Sewage of Coconut Water by Specific Primer 16S rRNA and Specific Methanogenic Gene
Authors: Kapahang Ardi , Bintang Maria , Solihin Dedy D 
Published: February 2021

Abstract
This study aims to transform metanogenic bacterial plasmid into E. coli C600 and to identify the products of methane from E. coli transformants. Isolate of methanogenic bacteria from cow’s feces as a positive control, named A and B. The transformation of isolate from the sewage of coconut water (P and M) plasmid to E.coli C600 using “Blind Test” method Fermentation of coconut water by E.coli transformant that yield gas was quality-analyzed by burning and quantity-analyzed by GC. The result of gen 16S rRNA analysis by PCR, there is a similarity of nucleotide around 1088 bp, which is the same as isolate A and B from cow’s feces. The result of gen mcrA’s PCR on isolate P, M and isolate A and B have the similarity of nucleotide which is around 600 bp. The sequencing of gen 16S rRNA isolate P yielded nucleotide with composition respectively G 31.25%, C 20.58%, A 27.11%, and T 21.04% while the isolate M with composition respectively G 31.25%, C 20.31%, A 27.02, and T 21.32%. The identification of isolate M is similar with Clostridium tyrobutyricum (100%) and isolate P is almost similar with Clostridium tyrobutyricum (99%).
The role of information technology on the online learning success based on self-regulated learning data
Authors: Sulisworo Dwi , Maryani Ika , Kusumaningtyas Dian Artha 
Published: February 2021

Abstract
Strategies in Covid-19 mitigation positively acquire changes in individuals’ conduct. Teachers and students hurry to vary their interaction using online learning. In online learning, where learning control is higher in students, self-regulated learning or SRL becomes a fundamental issue to check. This research could be a quantitative descriptive study to elucidate how the SRL profile of scholars in Covid-19 emergencies. The information was gathered using Google Form. The SRL questionnaire covers four subscales: planning (5 items), monitoring (6 items), controlling (6 items), and reflecting (5 items). Profile of SRL is grouped at high, moderate-low, and low SRL compared to the common SRL of all students. However, students as an entire tend to own quite high SRL. So it is often expected that students won’t encounter learning problems by using online learning.
Gamification in Learning using Quizizz Application as Assessment Tools
Authors: Handoko Wiwin , Mizkat Eva , Nasution Auliana , Hambali  , Eska Juna 
Published: February 2021

Abstract
Nowadays, Teaching and learning activities in the world of education must always follow the development of technology. The use of these technologies will make these activities more effective and efficient. Gamification is part of innovation in education. In this research, gamification is used as a tool for studying activities in project management information systems subject. The method used is technology-based applied research. The Assessment Tool in this study uses Quizizz. Quizizz is used on midterms. This exam was attended by 29 students of the information systems department STMIK Royal. The questionnaire was made using a Mentimeter. The use of Quizizz has a positive impact. The level of student answers questions correctly is 51%. Then 66% prefer Quizizz as assessment tool compared to paper and google forms.
Technical Guidance for Learning Management in a Video Conference with the Zoom and Youtube application in the Covid-19 Pandemic Era
Authors: Agusriadi Agusriandi , Elihami Elihami , Mutmainnah Mutmainnah , Busa Yunus 
Published: February 2021

Abstract
Learning conducted by teachers and lecturers will not take place without online management in the current pandemic covid-19. Therefore, the technical guidance organized by LPPM University of Muhammadiyah Enrekang aims to provide teachers and lecturers with understanding and skills on how to manage learning online or online. This stage of research includes analyzing the need for an online learning management platform, conducting technical guidance, and conducting evaluations. After the technical guidance activity, the participants liked the material and speakers in the technical guidance which indicated that the participants understood the material presented by the resource persons. Based on the evaluation results it was found that the implementation of this activity was successful with a high level of attendance of the participants, a level of likeness that was evenly distributed in all material presented by the resource persons, and a very high level of satisfaction with the guidance committee services.
Kahoot Application for Elementary School Students: Implementations of Learning Process from Distance during Pandemic period of COVID 19
Authors: Djannah Mahfira , Zulherman  , Nurafni  
Published: February 2021

Abstract
Kahoot Applications has been one of the media of the learning process to be developed further. It can become media of the learning process as well as a tool for measuring/index of the target. These analyses observe the result of the learning process based on Kahoot Application towards the fifth grade of elementary students in the context of single and complexes theory. This kind of Media of learning process is more likely effective used in the argent situation of the Pandemic COVID 19 period that is inevitable for the mechanism of the learning process from home which should be supported by internet connection. This product is made by the learning development of ADDIE. The method of analysis used is the method of surveying. The Data taken from surveying uses a Likert scale from a score within 1 to 5. They are three expertise from material aspects and the media aspect, 5 teachers from the fifth grade of elementary from different schools, and is examined for 149 students from 5 different schools to examine the result. The result stated that Kahoot’s application as the media of the learning process is efficient and proper being used as a learning and teaching process because Kahoot applications allow enhancing students’ interest and motivations to be more likely focus to on learning process for the better result of learning mechanism.
Factor Affecting E-Learning User Acceptance: A Case Study of AULA
Authors: Effendy Faried , Kurniawati Octa Dwi , Priambada Guntung 
Published: February 2021

Abstract
E-learning is a strategy that is expected to transform ordinary learning into a learning philosophy that can be adapted, shared, reusable, and versatile. Based on previous research, e-learning acceptance is influenced by many factors. However, there are still some things that have not been determined and discussed; Therefore, they need further investigation. Based on previous assumptions, this study is an attempt to examine the factors that influence student acceptance of e-learning at Airlangga University, Indonesia. In this study, the Technology Acceptance Model (TAM) and (Information System) IS Success Model were combined to test intention, user satisfaction, and actual use of e-learning. This research was conducted by distributing online and offline questionnaires to 100 student respondents; then processed the data using SmartPLS 3.0. The results showed that e-learning user satisfaction was influenced by the quality of education, service quality, and information quality. At the same time, the intention to use is influenced by the quality of education. In addition, user satisfaction and intention to use e-learning affect the actual use of e-learning. This research is expected to help decision-makers from higher education to better understand the effectiveness of using e-learning by students.
Teacher’s intention to use online learning; an extended technology acceptance model (TAM) investigation
Authors: Ngabiyanto  , Nurkhin Ahmad , Widiyanto  , Saputro Iwan Hardi , Kholid Al Mamnukhin 
Published: February 2021

Abstract
Pandemic covid-19 requires teachers everywhere to take advantage of online learning. This study aims to investigate the factors that affect the teacher’s intention to use online learning based on the extended Technology Acceptance Model (TAM) approach. The extended TAM developed from the previous research. The population of this study were the teachers at Al Asror Islamic Boarding School. The data was obtained by using a questionnaire. The analytical method used was multiple regression analysis. The result showed that only perceived usefulness and teacher’s readiness had positive and significant impact on teachers’ intention to use online learning. There was negative and significant influence of perceive of ease of use on teachers’ intention to use online learning. Prior experience and computer knowledge didn’t have significant impact. The results also showed that prior experience and computer knowledge had a significant and positive effect on perceived ease of use and perceived usefulness. Teacher’s readiness was the most dominant factor among other variables.
LMS-Google Classroom Digital Platform: Impact on the Critical Thinking Ability, Self-Concept, and Mathematics Anxiety of Pre-Service Mathematics Teachers During the Covid-19 Pandemic in Indramayu, Indonesia
Authors: Mellawaty  , Taufan Mochammad 
Published: February 2021

Abstract
The purpose of this study was to determine the effect of self-concept and mathematics anxiety on the ability to think critically pre-service teachers of mathematics at the time of a pandemic Covid-19 in Indramayu, Indonesia with used digital platforms LMS-Google Classroom. This type of quantitative research uses one group pre-test post-test design. By using the purposive sampling technique, the research sample taken is the fourth-semester students who take the Abstract Algebra of Theory Ring course as many as 19 people. Research instrument in the form of critical thinking skills tests, self-concept questionnaires, and mathematics anxiety. Data analysis using ANOVA test. Based on the results, there is a direct influence self-concept and mathematics anxiety on the ability to think critically pre-service teachers of mathematics at the time of a pandemic Covid-19 in Indramayu, Indonesia by using a digital platform LMS-Google Classroom. There are other findings obtained, namely: the readiness of the lecturer in preparing the learning process must be very correct and can add applications that can face virtual eyes with students, such as the use of Zoom Meeting; the readiness of pre-service teacher in following the lecture process in the form of stable internet use because 90% of pre-service teacher come from the border area of Indramayu district and surrounding districts.
Media Information Communication and Technology (ICT) Development Strategy in Education Learning
Authors: Yusuf Achmad , Munif  , Hasyim Mochamad , Anan Asrul , Hadi Muhammad Nur 
Published: February 2021

Abstract
In the era of globalization in the learning process educators are more likely to use media based on information and communication technology (ICT). ICT-based learning media is a tool used in pai learning process by utilizing information technology. This is because the development of ICT has implications for the development of the education system, from the basic level to the higher education level. Some strategies that can be done in the learning process through ICT Development in multicultural-based PAI learning included; Active learning, Collaborative learning, Creative Learning, Integrative learning, and Evaluative learning. Media development with ICT has a purpose; first, the availability of flexibility for students in choosing study time, as well as regardless of stress due to the influence of geographical location. Second, through the ICT facilities available, students are expected to be able to explore and also discover new ideas or innovations from experts around the world. And third, the existence of ICT in the education system allows some enforcement activities, such as the delivery of lectures to students, monitoring the progress of students, and assessments can be done on time.
Temperature Effect on Particulate Matter Concentrations PM 10 during the heating season in Burgas
Authors: Hasan F B , Midyurova B N , Mihalev T M 
Published: February 2021

Abstract
In the present paper, the dynamics of particulate matter (PM) concentration during the heating season was studied with respect to the seasonal dynamics of the temperature recorded at two measuring sites from the National system for monitoring of air quality in Burgas. The automated measuring stations (AMS) selected for the present study are located in Dolno Ezerovo (DE) and Meden Rudnik (MR) in the municipality of Burgas. This study looks at the impacts of Temperature on localised PM10 concentrations in an urban area of Burgas over the winter period. The levels of PM 10 pollution is an important characteristic for the quality of life in urban environment. The main source of PM 10 emissions is considered to be the domestic heating with wood which varies with the values of the temperature during the heating season.
Juniperus waste wood as a source for obtaining pellets by single-screw extrusion method
Authors: Simitchiev A T , Lazarov L V , Fidan H N , Bozadzhiev B V , Stoyanova A S 
Published: February 2021

Abstract
Waste wood (biomass) is one of the most valuable and multifunctional environmental, long term resources of Earth. The aim of this paper was to study the possibilities for obtaining pellets from Juniperus. excelsa M. Bieb. biomass by a single-screw extrusion pre-treatment method. Biomass obtained after aqueous distillation of J. excelsa was used. The sample was grounded and sieved into dp ⩽ 500 μm and dp ⩽ 500 μm particle in size. The experiments were carried out on a single-screw laboratory extruder “Brabender 20 DN”. According to our results, the pellets with dp < 500 μm particle size were characterized with the following indicators: the mass flow rate (1.92 kg/h), sectional expansion index (1.03), specific mechanical energy (215.65 kJ/kg), density of the extrudates (0.44 g/cm3) and volumetric flow rate (4337.58 cm3/h). The samples obtained with dp > 500 μm particle size showed the following characteristics: the mass flow rate (1.30 kg/h), sectional expansion index (1.09), specific mechanical energy (535.23 kJ/kg), density of extrudates (0.48 g/cm3) and volumetric flow rate (2719.78 cm3/h). The biomass was a potential source for biofuel production. Pellets produced from biomass with a particle size dp > 500 μm had a higher density and sectional expansion index than those with a particle size dp ⩽ 500 μm. However, their production was more economically impractical, which is due to their lower mass and volumetric flow rate, as well as higher specific mechanical energy.
Theoretical determination and analysis of the length of the non-working move and of the width of the headland when performing a fishtail turn with a curvilinear reverse move by a machine-tractor unit with a mounted machine in an irregularly shaped field
Authors: Trendafilov Krasimir 
Published: February 2021

Abstract
Machine-tractor units with mounted machines most often perform fishtail turns with a curvilinear reverse move when changing the direction of movement at the end of the field. In an irregularly shaped field, the shape of turn and the width of the headland depend on the angle between the direction of the working move and the field boundary and the direction in which the working moves alternate in the field. The article presents dependences for determining the length of open and closed fishtail turns with a curvilinear reverse move and the width of the headland. An analysis of the influence of the angle between the direction of movement and the field boundary on the length of the non-working move and the width of the headland is made. It has been found that when the unit moves in the field from right to left, the length of the non-working move is the smallest and constant, except in cases where the angle between the direction of movement of the unit and the field boundary is very small. The headland has a smaller width in open turn from left to right and closed turn from right to left. When the angle between the direction of movement and the field boundary is small, the closed turn must be performed when moving in the field from left to right.
Experimental evaluation of the effectiveness of a diesel fuel additive
Authors: Mihaylov V , Ivanov Z , Belchev S , Petkov D 
Published: February 2021

Abstract
One of the ways to reduce carbon emissions is by lowering the energy consumption of vehicles. Electrical or hybrid cars can help for lower emissions from transport in nearby future, but a big step can be achieved now if there is a way to reduce fuel consumption in current fleet. The use of fuels with improved characteristics or use of fuel additives, which can affect fuel physical and combustion properties, are promising measures in this direction. Due to advances in chemistry science and the research done in this area, it is of practical interest what the achievable benefits are nowadays. The aim of this research is to study how a popular present day commercial additive affects the fuel consumption and environmental performance of a high-speed diesel engine. In this paper are shown the results from performed studies on a direct injected diesel engine when working with additive, aimed to improve its energy consumption and hence its reduction in carbon emissions. The results show improvement in some of the harmful emissions, but no improvement of engine’s efficiency.