bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of neem (Azadirachta indica) seedlings on compost and urea fertilizer dose treatment
Authors: Widnyana I M A , Mahardika I B K , Suarta M , Kartini L , Yuliartini M S , Situmeang Y P
Published: April 2021

Neem (Mimba) is one of the types of plants that are the potential to be developed commercially as plantations and community forests. The purpose of this research is to find outperformance of neem seedlings on compost and urea fertilizer dose treatment. This experiment consisted of two factors arranged factorially using a Randomized Block Design. The first factor is the dose of compost with three levels, namely 200 g, 400 g, and 600 g per pot. While the second factor is the dose of urea fertilizer which consists of two levels, namely 2.5 g and 5 g per pot. The results showed that there was an interaction between compost dose and urea dose and had a very significant effect on root length per seed and significantly affected oven-dry weight per seedlings of neem. The highest root length of the neem seedlings of this experiment indicates that the doses of compost at a 200 g per pot and urea fertilizer of 2.5 g per pot was 28.00 cm and oven-dry weight of the roots of neem plant seeds was 2.81 g.
Physical quality of some types of grass on mixed planting with Arachis pintoi and organic fertilizing
Authors: Wawu F U K , Sudita I D N , S Rejeki I G A D
Published: April 2021

Increased livestock productivity is largely determined by the availability of sufficient forage. Good forage is determined by digestibility, which is related to physical quality. This study aims to determine the physical quality of several types of grass planted with Arachis legumes and the provision of organic fertilizer. This study used a Randomized Block Design with a factorial pattern consisting of 3 types of grass planted with Arachis legumes (factor A) and fertilizing 2 types of solid and liquid organic fertilizer (factor B) with 3 replications. The treatment combinations are: R1C (Paspalum notatum with Arachis pintoi+Compost), R1B (Paspalum notatum with Arachis pintoi+Biourine), R2C (Paspalum conyugatum with Arachis pintoi + Compost), R2B (Paspalum conyugatum with Arachis pintoi +Biourine), R3C (Axonopus compresus with Arachis pintoi+Compost), R3B (Axonopus compresus with Arachis pintoi+Biourine). The results showed no significant difference (P>0.05) both in the mixture of some grass plants with Arachis pintoi and the provision of organic fertilizer on the physical quality of forage. In planting a mixture of Axonopus comprsus grass with Arachis pintoi showed average dry matter (DM), water regain capacity (WRC), and water solubility (WS). Whereas compost gets higher average values than biourine for dry matter, WRC and WS. The combination of mixed planting and fertilizing, compost showed the highest average, especially water solubility (WS). From this research it can be concluded planting a mixture of grass and legumes fed with compost on average is better for the physical quality of the grass, but not significantly different (P>0.05) from all treatments.
Electroanalytical evaluation of antioxidant activity in monofloral honeys
Authors: Suliasih B A , Tawwabin R A , Budi S
Published: April 2021

The objective of this study was to develop an electroanalytical technique for the analysis of antioxidant compounds. Five different samples from five monofloral honeys were used. The electroanalysis experiments were conducted using two different techniques, namely cyclic voltammetry (CV) performed with a scan rate of 50 mV/s and differential pulse voltammetry (DPV) with a pulse amplitude of 50 mV and a scan rate of 10 mV/s. All samples were also analyzed by spectroscopy techniquesusing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) microplate method. The electrochemical index determined using the DPV technique agreed with the spectrometric DPPH measurements. This resultdemonstrates that the electroanalysis method could potentially be utilized for antioxidant analysis of honey samples.
Isolation flavonoid compound chrysoeriol from ethyl acetate extract of zaitun leaves (Olea europaea)
Authors: Supriadin A , Juliani H , Tanyela N
Published: April 2021

The Olive Tree (Olea europaea) is a plant originating in the Middle East. Olea Europaea plant is contained several secondary metabolites such as olive oil, phenolic compounds, flavonoids, triterpen, biphenol. The aims of this research are to isolate and identify a flavonoid compound that extracted in the ethyl acetate of olive leaves. Isolation was carried out by meseration, liquid vacuum chromatography, column chromatography and thin layer chromatography. Isolation results obtained 10 mg isolates were identified using proton nuclear magnetic spectroscopy (1H-NMR) and carbon (13C-NMR). According to spectra analysis, describe that isolate is chrysoeriol.
The comparison characteristics of fermented Virgin Coconut Oil (VCO) on kefir addition
Authors: Karlina M , Windayani N , Helsy I
Published: April 2021

Indonesia is the largest coconut producing country in the world. They are many products from coconut that have high economic value, one of them is VCO. No research has been found in making VCO by kefir fermentation, so the purpose of this research is to describe the comparison of characteristics VCO produced on kefir addition based on organoleptic, water content, and free fatty acid tests. This research was carried out using two replications of the three old coconuts obtained 1.26 L thick coconut milk, then divided into three samples, fermented 48 hours with different treatments (0% kefir for control; 3.5%; 6% kefir). The results of this study obtained the best VCO characteristics in the composition of 3.5% kefir addition, colorless, normal taste, and aroma of coconut aroma, with water content of 0.0028% and a free fatty acid content of 0.23%. The VCO produced are in accordance with SNI VCO 7381: 2008. Further research needs to be conducted to produce an optimal VCO randement with a range of 1-3.5% kefir addition.
Dioscorea alata L anthocyanin extract methanol as a sensitive pH active compound
Authors: Safitri E , Humaira H , Nazaruddin N , Susilawati S , Murniana M , Md Sani N D
Published: April 2021

Anthocyanin from Dioscorea alata L has been successfully extracted using a methanol solvent and has been tested for its sensitivity to pH changes using a UV-Vis spectrophotometer in citrate and phosphate buffer solutions. The extracted anthocyanin showed positive flavonoid and phenol tests. The total yield of crude extract was 1.63% that is related to 3.34 x10−7 M or 16.72 mg/kg dried sample. The maximum absorption against citrate buffer is at a wavelength of 600 nm with a linear range toward pH 4 to 8, sensitivity = 0.121 and R2 = 0.98. Furthermore, the maximum absorption for phosphate buffer occurs at a wavelength of 590 nm that has a response linear in the range of pH 6 to 8 and sensitivity = 0.296 (R2 = 0.97) The optimum concentration of citrate buffer is 0.1M with a linear pH of 4-8 and sensitivity = 0.121 (R2 = 0.98). The optimum buffer concentration for both citrate and phosphate buffer solutions were reached at 0.1M and 0.075 M, respectively. The extracted anthocyanin showed stable response properties against citrate and phosphate buffer for 140 minutes during the test period. This anthocyanin is potential to be used as an active substance to developed optical pH sensors and biosensors based on the determination of pH change.
Molecular docking simulation of interaction between insulin and silica nanoparticle
Authors: Hertadi R , Ivansyah A L
Published: April 2021

Molecular docking simulation has been done in this research by using Hex version 8.0 software package, respectively, to explore the interaction between insulin and silica nanoparticle. Silica nanoparticle acts as receptor and insulin acts as ligand in this research. It was found that insulin form more stable interaction when it is in the pore of silica nanochannel than on the surface of silica nanosheet. Insulin prefer to interact with silica atoms than oxygen atoms in the pore of silica nanochannel
RGB-ColorMeter on smartphones as a simple spectrophotometer: An alternative method of teaching spectrophotometry at the vocational high school of chemical analysts
Authors: Paristiowati M , Moersilah M , Nurjayadi M , Fitria A N
Published: April 2021

This study aims to improve students’ understanding at the Vocational High School of Chemical Analysts on spectrophotometric concepts through experiments using smart phone technology. For this research, The ColorMeter application with matching red green blue (RGB) colors is used as a simple spectrophotometry. The use of smartphone as a simple spectrophotometry in practicum can maximize spectrophotometric learning activities in the classroom since these are often constrained by the limited access to the instrument. Through finding an alternative method, learning objectives can be properly achieved and practical application is easily attained. This RGB – ColorMeter application can be used to read the transmittance of a colored solution by utilizing the complementary colors of the solution being tested. Transmittance data obtained is used to find the absorbance of the solution, so that it can determine the concentration of a substance in the solution. The results showed that the application of RGB - ColorMeter can show a linear graph between concentration and absorbance. The whole process is then carried out individually by each student starting from the stages of designing, utilizing, and reviewing this simple spectrophotometer. Students’ understanding of spectrophotometric concepts increases because each student follows the process thoroughly from the beginning to the final stages of the spectrophotometry practicum. Thus, it can be deduced that the application of RGB-ColorMeter can be used as a simple and accessible spectrophotometer in the spectrophotometry practicum at the Vocational High School of Chemical Analysts.
A robust method of rectifying a tilted image to truly vertical
Authors: Tjahjadi M E , Handoko F
Published: April 2021

Unmanned Aerial Vehicle (UAV) is burgeoning technology for conducting aerial photography ranging from recreational purposes to engineering works. Due to its physical design, a mounted camera onto the UAV body is afflicted by engine and other vibrations during flight data acquisitions. In such condition, it is impossible to maintain the camera optical axis truly vertical while it is directed downward to the ground. Unavoidable aircraft tilts causes captured images to be exposed with the camera axis tilted slightly from vertical. In survey and mapping activity when vertical images are intended, the amount by which the optical axis deviates from vertical of more than 3 degrees is not met the work specification. Truly vertical images are necessary for producing high quality map from aerial images. This paper offers robust solution to rectify tilted images to generate equivalent truly vertical ones. We use exterior orientation parameters of the tilted images to perform double steps of transformation while resampling grid tessellations of the vertical images. To visualize the result, the transformation processes are coded by C++ programing language. The program results show a feasibility of our approach.
The adoption of information technology as decision support system in SMEs
Authors: Tyasari I , Sarwoko E , Nurfarida I N
Published: April 2021

The purpose of the study is to develop the information systems (IS) for SMEs as well as to investigate the factors that influence the decision of SMEs to adopt information technology (IT). Using a development research approach, it focuses on developing the Web-based Decision Support System (DSS) IT on SMEs, with the Waterfall model’s implementation. Structured interview (by phone) was conducted with 120 SMEs, and the results were tested using Confirmatory Factor Analysis. It shows that the implementation of the Web-based DSS for SMEs provides benefits for them as a database for management decision-making tools. In addition, it is also beneficial to the Indonesian policy makers in regards to the empowerment of SMEs. The findings of the study confirm the Technological, Organizational and Environmental (TOE) framework, that the decision to adopt IT by SMEs in Indonesia are influenced by technological factors including consideration of benefits, compatibility, and costs; organizational factors include the readiness of companies to adopt technologies including technological infrastructure readiness, relevant systems, and technical skills; environmental factors include customer/supplier pressures and competitor pressures. The findings also show that different sector of SMEs (manufacturing and service sectors) has different considerations in deciding the implementation of IT.
Snake and digital ladder applications involving the behavior of children applying the health protocols
Authors: Ariessanti H D , Gaol F L , Supangkat S H , Ranti B
Published: April 2021

This study defines the problem of how understanding health protocols during a pandemic is correctly conveyed according to age levels. This problem for the Government to implement gamification by modifying game media through snake and ladder game that can socialize health protocols for pre-school. Measuring the acceptance of a snake and ladder game media can be considered as a learning medium from the Government which will refer to four components (game content, ease of play, appearance, and active player involvement). The purpose of this study was to modify online-based games as a learning media and to measure children’s active interaction with parents in practicing health protocols during game play. This study will use a quantitative approach with data techniques through playing together experiments and filling in online research questionnaires from 115 samples as participants (7 Kindergartens). The results show that the snake and ladder digital game can have a significant effect on changes behavior in implementing health protocols. This research can provide a contribution that can be used as a reference for the Government to design a strategy for socialization through gamification.
Analysis of transaction patterns at drug store with Apriori Algorithm
Authors: Kusumo H , Marlina D , Novita M , Anwar M T
Published: April 2021

Data mining is a method for finding hidden data from big data which has been continuously applied in various fields such as marketing, education, bioinformatics and so on. Drug store is one of the business sectors that might take the advantage of the data mining. In the drug store, there is a sales transaction data which contains a big number of data. However, there is a limited number of analysis based on this sales transaction data. There are several information that can be obtained from this big data; one of them is the combination of items that consumers often buy. Apriori Algorithm is a data mining method that has been widely used in order to determine the combinations of frequently purchased products. By using the Apriori Algorithm in the sales transaction data of the drug store.
The development of thematic modules based on Strengthening Character Education (PPK) and Quick Response (QR) code
Authors: Rahayu S , Andayani E D P , Chrisyarani D D , Ladamay I
Published: April 2021

Less attractive and effective learning modules in thematic learning and less reinforcement in character education make students bored and do not really implement strengthening character education in the school environment and society. Therefore, alternative teaching materials are needed in thematic learning and strengthening student character education. The purpose of this research is to develop thematic modules based on PPK and QR code. This study applied the Bog & Gall development research model. The data analysis technique used was quantitative and qualitative data analysis. The research instruments used were observation, questionnaires and documentation. The results of research on the development of thematic modules based on PPK and QR Code, it is known that the results of the analysis of media experts obtained a score of 92.86 percent with a very valid category, material experts obtained a score of 88.64 percent in the very valid category, linguists obtained a score of 75 percent with a fairly valid category, the response of educators obtained a score of 89.92 percent in the very practical category, the response of students obtained a score of 87.78 percent in the practical category. Based on the results of the explanation above, the thematic module based on PPK and QR Code can be used as a supplementary teaching material for the thematic book to make it easier for students to acquire the lesson content and apply characters education in schools and communities.
Rainfall prediction using Extreme Gradient Boosting
Authors: Anwar M T , Winarno E , Hadikurniawati W , Novita M
Published: April 2021

Rainfall greatly affects human life in various sectors including agriculture, transportation, etc. and also can affect natural disasters such as drought, floods, and landslides. This situation prompts us to build an accurate rainfall prediction model so that prescriptive measures can be made. Previous research on rainfall prediction uses models that have their limitations and thus produce poor performance. This study aims to build a multivariate rainfall prediction model using the best performing technique to date namely the Extreme Gradient Boosting. This model is built based on 7 years of historical weather data collected by the weather station. The result had demonstrated that the model is capable of producing accurate predictions for daily rainfall estimates with training RMSE of 2.7 mm and the testing MAE of 8.8 mm.
“Say no to coding”: Designing of mobile-app-based learning media using Glide apps
Authors: Rahmawati A I N , Ariffudin I , Latifah L , Soejanto L T
Published: April 2021

Designing mobile-app-based learning media is challenging for educators with minimal programming skills. This paper aims to introduce a conceptual model as a framework for designing learning media. In this paper, we discuss steps by step a mobile-app-based learning media designer by using glide apps. Descriptive qualitative with literature review design was used in this article. Based on the literature review, it can be known that glide app can design a mobile app which easy to use, build without code, applicable for the m-learning era, and used for free. However, the creation of a mobile app in education should be careful, because it needs to be adjusted to the age level and psychological characteristics of students. Therefore, educators can use the glide app as an alternative to m-learning media designers.
“States of Matter” electronic worksheet assisted by Powtoon based on Sigil
Authors: Hakim A R , Yulia N K T
Published: April 2021

The purpose of this research was to describe the development of worksheets based on Sigil and Powtoon. This research and development used ADDIE Model. The research subjects were III grade elementary school students. The data collection instruments used a validation sheet and a questionnaire. Data analysis techniques used qualitative and quantitative data. The results of the evaluation of material experts and media experts obtained valid criteria with an average score of 86.36% for material experts and 87.5% for media experts. The responses given by students on this worksheet were 92.91% in the “very interesting” category. Based on these findings, it can be concluded that Sigil and Powtoon-based worksheets are suitable for use as instructional materials.
Probing time series multiplicative model and fuzzy relation methodologies
Authors: Pratiwi H I , Heriadi Y , Lukas L , Wibowo A
Published: April 2021

Probing of a question between two methodologies of the multiplicative model of Time Series and Fuzzy Relation is challenging to answer, without exploring each of both theories. This paper aims to discern any discrepancies or similarities in them, since each has detailed items that could lead to practical advantages to proceed on forecasting or decision making. Pseudo coding is a chance to explore theories and to surface those practical advantages. The finding states that the multiplicative model of time series factually has components that could have dependencies one to another, and the fuzzy relations help to map each point along their processes to determine how much dependency contained in the system that could conclude of a decision making.
Design of information systems of reporting the performance of honorary employees at the web based office of communication and informatics in Blitar Regency
Authors: Setiyaningsih W , Purwanto H L , Susanto G , Ahsan M , Eko A Y , Trestiarso Y , Daryanto D
Published: April 2021

The Office of Communication and Informatics of Blitar Regency carries out its main tasks supported by temporary personnel with their respective work targets. To find out the number of performance targets that have been carried out and performance appraisals per year, the temporary staff must make daily and monthly performance reports to the leadership. So far, technical reporting uses Microsoft Excel which must be printed one by one before being reported. If there are errors on the report must edit one by one. Each sheet stores daily reports so that many sheets are used to store reports in one month. Reports submitted to the leadership are still in copy which is prone to loss. This has a negative impact on the deadlines for collecting reporting and monitoring by the leadership. Based on these problems, a Web-Based Performance Reporting Information System was built to optimize performance reporting. The system is built with 3 access rights: admin, leadership, and non-permanent personnel, employee mastering and performance targets with targets, as well as daily and monthly reporting transactions. From the test results, the system with UAT 89.8% has been able to optimize performance reporting with the output of performance values per month and per year completed with graphs of performance targets.
Fault tolerance strategy to increase Moodle service reliability
Authors: Zaini A , Santoso H , Sulistyanto M P T
Published: April 2021

Moodle is one of online Learning Management System that can be downloaded and installed on our server for free. Moodle is suitable solution for universities to organize online learning. Changing all learning activities from offline to online during a pandemic situation, especially for universities, requires Moodle services to be reliably available. The more students it means the more traffic should be handled by Moodle server. Moodle consists of system, user’s data and a database. To increase Moodle reliability, we can rely on these components. We can use virtualization technology to simplify migration system and recovery process. Distributed file system technology is a best solution to store Moodle user data because it can be replicated into several nodes and support for high availability. Finally, the last component of Moodle is a database, we can replicate the database into several machine to increase availability. At the top of every Moodle component, we need cluster control to make sure all of Moodle components can be accessed. The results show that with the right fault tolerance strategy, all requests can be responded to 100% without error. In addition, this strategy can also increase the response time 12 times faster when compared to a single server.
Innovation of village governance based on technology 4.0: Case study in the new otonom district
Authors: Heri H , Caesar M R , Zakaria M , Suhendar D , Sulaeman A , Alamsyah T , Yusuf M D , Nuryani E , Undang G , Sumardi I
Published: April 2021

The problem in this study is that the use of technology has not been optimal in developing village potentials associated with opportunities for village innovation programs. The problem arises because not all villages have the same capacity in aspects of the potential and capacity of village officials, so that in response to this policy the village innovation program is an alternative solution to the problem of inequality in capacity, resources, and so on. This study uses a dynamic model of village development and innovation to analyze technology-based village innovation governance in new autonomous regions. The method used is a qualitative method which relies on secondary data with descriptive data analysis techniques. The results show that the factors in the dynamic model of rural development and innovation are based on internal and external factors. Internal factors include human resources and knowledge, information and communication, community participation, leadership, local wisdom, local potential, experience, challenges and obstacles. External factors include legal umbrella, networking and cooperation, government support, as well as appreciation and incentives.
ServQual and WebQual 4.0 for usability check academic information system of private university
Authors: Rahmat T , Nuryani E , Siswanto D , Undang G
Published: April 2021

This study aims to determine the level, correlation, and influence of the usability of academic information system services using the ServQual and WebQual 4.0 methods. The research method used is qualitative-qualitative and data collection through a survey verification consisting of 20 statements. The questionnaire statement uses a Likert scale with 100 student respondents as the main users. The sampling technique uses a simple random sampling technique. Then, the data analysis in this study uses path analysis. The results showed that ServQual was at an average score of 2.60, WebQual 4.0 was at an average score of 2.59, and the average score for the User Satisfaction variable was at 2.66. Academic information system improvement will have a major effect on User Satisfaction. This is by the results of the verification analysis which shows that ServQual (X1) and WebQual 4.0 (X2) have a positive effect simultaneously on User Satisfaction (Y), with a total effect of 0.688 or 68.8%. External influence of 0.312 or 31.2%. Thus, the academic information system in small and medium-scale private universities needs to be improved on the WebQual 4.0 variable and can be added by ServQual improvements, and ServQual improvements can also be done without including WebQual 4.0.
BD-Print: An Android based for bilingual digital promotion of integrated tourism in Garut Selatan
Authors: Cahyani R Y D , Hartono H , Sakinah R M N , Putra O N , Setyawati I E , Undang G
Published: April 2021

South Garut has tourism potential areas in Indonesia. However, the lack of government attention and information of the tourist area in South Garut resulted a lack of tourists coming. South Garut tourism will be more accessible by developing an information system that implements the Android system as a promotional medium to introduce tourist objects. This study is undertaken to design an Android-based BD-Print application to assist the development of the regional potential tourism sector in the Southern Garut. The BD-Print system development will use the System Development Life Cycle approach with the Waterfall method. This application has gone through several process such as planning, system analyzing, crafting, implementation, testing and development. Result of the experiment are: 1) The application programs created by using Android run well. 2) The features existed in the application program runs well as the main menu displays other menu options, login menu, tourism menu that displays some options of available tourist destinations, and mapping that displays the route from the current location to the location of the object destination tours. 3) This BD-Print application suits well as a reference for tourists that are going on a vacation without being accompany by tour guide.
Geographic Information System (GIS): Potential mapping of agribusiness in Southern part of West Java
Authors: Maskun T , Masluh M , Resmiawati E N , Tasdik K , Muhafidin D , Undang G , Putra O N
Published: April 2021

In this study, a mapping of the potential for agribusiness in the southern part of West Java was carried out, which serves as a policy material and business development in developing local potential in the agribusiness sector to improve local communities’ welfare. West Java Provincial Regulation Number 12 of 2014 divides the Southern part of West Java into three Growth Center (PP) zones, namely PP Palabuhanratu, PP Rancabuaya, and PP Pangandaran. The agribusiness potential of South West Java is dynamic and varied. However, it has not been developed optimally to improve local communities’ welfare, which is generally scattered in underdeveloped villages. The government and developers (entrepreneurs) have difficulty obtaining digital data updates. The purpose of this research is to map the regional potential in the field of agribusiness in the form of digital data to facilitate the development of agribusiness potential in coastal areas located on the shores of the Indian Ocean (Indonesian Ocean). The research method uses Geographical Information Systems. The results showed that the potential and variants of agribusiness in PP Palabuhanratu are spread across 5 districts. In PP Rancabuaya spread into 5 districts. Meanwhile, PP Pangandaran is spread over 5 districts. This research can be used as policy materials and business development in developing local potential in the agribusiness sector to improve the welfare of the people of West Java.
Decision support system for mapping SMEs batik Bangkalan facing industry 4.0 using SMART method
Authors: Kustiyahningsih Y , Anamisa D R , Mufarroha F A
Published: April 2021

There are many criteria and alternatives in determining recommendations and mapping of SMEs, so a decision-making method is needed. The SMART method is a multi-criteria decision-making technique where each alternative consists of number criteria that have values and describes how important the criteria are compared to other criteria. This weighting is used to assess each alternative in order to obtain the best alternative. Industry 4.0 criteria used are owner education, production results, information technology certified employees, having a marketplace, online payment facilities, online marketing media, e-commerce systems and information systems for SMEs. The purpose of this study is to map SMEs in Bangkalan into 4 levels in order to carry out work programs in the face of the 4.0 industrial revolution using the adaptive SMART method. The results of this study are 35% entered the mature readiness stage of Industry 4.0, 28% entered the early readiness stage and 37% entered the intermediate readiness stage readiness stage. Accuracy results the feasibility of the system by the SMEs cooperative office and SME players was 91.15 %.
The effect of deproteinization temperature on chitosan extraction for iron metal ions adsorption: Case study in Bangka post tin mining water
Authors: Aldila H , Fabiani V A , Dalimunthe D Y
Published: April 2021

This study aims to analyze the effect of deproteination temperature on the chitosan adsorption for iron metal ions in Bangka post tin mining water. Extraction of chitosan was carried out in four steps: deproteinization, demineralization, decolorization and deacetylation of chitin. The effect of deproteinization temperature on deacetylation process was studied. The results shown that the increase of deproteinization from 30°C to 90°C causes the decrease of chitosan deacetylation degree (DD): 65.72%; 64.31% and 63.75% respectively. The increase of deproteinization temperature triggers excess depolymerization which damages the chitin structure so that it has a negative effect on the chitosan DD. The metal content of iron in post tin mining water sample this study reached 6.1 ppm. Adsorption of chitosan on iron metal ions reduced the dissolved levels reaching an average of 99.67% from the initial content. The adsorption of iron lead by chelation mechanism. The reaction of chitosan with iron metal ion lead the formation of complex compounds with chitosan as a ligand and metal ions as the central ion. Based on the ligand strength series in spectrochemistry, the hydroxyl functional group is to the left of the amine group, so that the amine group is stronger than the hydroxyl group in adsorbing metal ions. It is more likely to predict that the valency forces through the sharing of electrons between transition metal cations and adsorbent are the adsorption behaviour may involve.
Prediction on the multiplet energy diagram of α-Al2O3: Mn4+under pressure
Authors: Novita M , Marlina D , Kusumo H , Anwar M T , Ogasawara K
Published: April 2021

To review the recommendations for the production of novel red phosphor materials, in this work we established the multiplet energy diagram of Mn4+in a-Al2O3under pressure. By the discrete variational multi-electron (DVME), the calculations were conducted based on many-electron approaches. Since the experimental data of Mn4+in a-Al2O3at zero pressure was the only data reported so far, the results in this work are our predictions. The effect of increasing pressure is naturally similar with the effect of decreasing bond length. This work indicates that the multiplet energies responsible for the absorption process increase as the pressure increase. Whereas, those responsible for the emission process decrease. These tendencies are the same as our previous calculations on a-Al2O3: Cr3+.
Exploration of self-regulated learning: Mathematical problem solving
Authors: Nugroho A A , Dwijayanti I , Utami R E
Published: April 2021

Self-regulated learning is needed to regulate and direct itself, adjust, and control self-learning. This study aims to get an overview of students’ self-regulated learning in solving junior high school mathematics problems. This research is a qualitative descriptive study with three research subjects. The data collection techniques used math ability tests, problem-solving tests, self-regulated learning questionnaires, and interview guidelines. The results showed the profile of self-regulated learning raised by junior high school students when solving math problems, especially problems related to SPLDV, namely: 1) Planning, thinking and activation stages: (understanding the problem is expressed in using one’s own language or the language of the problem and there is an estimate of SPLDV completion through arithmetic procedures, logic and elimination substitution methods; 2) Monitoring Stage: monitoring is carried out on the correctness of the variables with or without involving the whole conversation; 3) Control stage: answer checking with reverse technique; and 4) Reaction and Reflection Stage: Explore the difficulties faced related to routine and non-routine problems.
Covid-19 sir model with nonlinear incidence rate
Authors: Fayeldi T , Dinnullah R N I
Published: April 2021

Covid-19 is part of worldwide pandemic since early 2020. Various mathematical models have been proposed to understand the behaviour of the disease, but most of them were failed to predict the biological phenomenon of this infectious diseases since they use incorrect assumptions due to early stage symptoms. The aim of this paper is to develop a covid-19 mathematical model with nonlinear incidence rate. We use some logical assumption to develop the model. We discretize the model by using Euler method. We use literature review in our research methodology. Then, we simulate the model by using computer software. We found that this model has two equilibrium points, namely disease free equilibrium point and endemic equilibrium point. The stability of the model is changed by increament or decreament of the step-size. If the step-size of the model is large enough, then it lead numerical solution to blown up. Finally, we also found that this model is fair enough to simulate the pandemic in our case. Also, we found some interesting phenomenon from our simulation that is the effect of government policies or social distancing. Further work is needed to analyze the stability of the model and the effect of delay.
The effectiveness of using magic book Math in Mathematics learning during the Covid-19 pandemic in Senior High School
Authors: Buchori A , Prasetyowati D , Wijayanto W
Published: April 2021

This study aims to find out the effectiveness of using augmented reality-based magic book math at State Senior High School 15 Semarang on student achievement. The type of research used was Quasy Experimental research. The population of this study was X grade students of State Senior High School 15 Semarang. With random sampling technique, two classes were selected, X grade of IPA 4 as the experimental class and X grade of IPA 2 as the control class. Data processing with t comparative test and regression effect test. The results showed that learning was said to be effective which was indicated by: a) the average value of learning achievement in the experimental class was 89.57 which exceeded the Passing Grade 70 limit; b) the effect of student responses can be seen from the value of R square = 0.882 which means 88.2% of student achievement was influenced by student response factors in learning using magic book math based on augmented reality; and c) the average learning achievement of the experimental class was 89.57 while the control class was 70.84, so the experimental class had a significantly better final score average than the control class average.
Misconceptions of prospective Mathematics teacher on graphing function
Authors: Syarifuddin A , Sari A F
Published: April 2021

Good learning outcomes supported by a good understanding of concepts. A good understanding of the concept is an understanding that do not contain misconceptions. This study aims to identify the misconceptions of prospective mathematics teacher on graphing function. This research was conducted on 8 undergraduate students. This study used a descriptive research design. Descriptive research is used to analyse conceptual understanding and student misconceptions based on test results using diagnostic test instruments and interview results. The questions used were 5 questions that had been validated by 2 mathematics lecturers with valid results. The results showed that most of the students were still doing plotting without identify of the domain dan characteristics of the function. Some of them were also still stuck with using integers as the reference.
Augmentation time series model with Kalman filter to predict foreign tourist arrivals in East Java
Authors: Purnaningrum E , Cahyaningtias S , Kusumawardhani D A
Published: April 2021

One of the focuses of Indonesia’s development is on the tourism sector. In addition, one of the supporters of the sector’s sustainability is the customer. So, customer satisfaction who comes and their desire to come back again, as well as an indirect promotion to other potential visitors. The availability and convenience of infrastructure and facilities are important to support this. In other words, the prediction of visiting foreign tourists is one form of alertness in preparing future tourism projections. However, the fluctuation of data for foreign tourists affects the effectiveness of the model in making predictions. Kalman filter is a stochastic deterministic model that can solve this problem. This study combines the time series model with the Kalman filter to determine the prediction of the number of foreign tourists visiting East Java. The results of these predictions can be concluded that the Kalman filter is able to handle fluctuating data with RMSE close to 0. The prediction for this paper could be help enterprise to decide future plan for give the tourist discount.
Geometry material: Profile of creative thinking process of prospective teachers with reflector learning style in proposing and solving problems
Authors: Ferdiani R D , Manuharawati M , Khabibah S
Published: April 2021

The purpose of this study was to describe the creative thinking process of students in reflector learning style in proposing and solving review problems from the Wallas stage. This research is a qualitative research. The subjects of this study were students of semester VII of the Mathematics Education Study Program of the University of Kanjuruhan Malang with the following criteria: a) age between 18-25 years, b) of the same gender, c) At least getting a B grade for the course of School Mathematics Development Studies. Researchers in this study acted as the main instrument and the supporting instruments used were Honey and Mumford’s Learning Style Questionnaire (LSQ) questionnaire, test sheets, and interview guides. Questionnaires will be given to research subjects, and subjects with reflector learning styles will be selected. Based on the researchers’ observations, it can be concluded that aperson with a reflector learning style will tend to prefer to observe, be careful in making decisions that will be seen at every stage of his creative thinking process.
Technology of Holobox Augmented Reality Grebeg Pancasila rite for Mathematics learning in Elementary School
Authors: Septinaningrum S , Hakam K A , Setiawan W , Agustin M , Sopandi W , Surur A S
Published: April 2021

The use of technology in learning needs to be encouraged starting from the elementary school level. Another thing that needs to be encouraged is local wisdom-based media to support character learning. This study aims to develop holobox augmented reality technology media of local wisdom of the Grebeg Pancasila rite for mathematics learning in elementary schools. This research produces multimedia based on technology Holobox Augmented Reality (AR) with the content of material Grebeg Pancasila for learning mathematics and building spaces in elementary schools. The method in media development using the Development Life Cycle developed by Luther consists of six stages, namely: concept, design, material collection, assembly, testing, and distribution. The media produced meets the standard of feasibility and can provide information and knowledge about understanding the concept of flat and space structures through the flag and gunungan symbols in the Rite Grebeg Pancasila. The implication of this study is that cultural diversity in local wisdom of the Rite Grebeg Pancasila can be used as a medium for learning mathematics in elementary schools (MI/SD) through Technology Holobox. Augmented Reality.
Analysis of mathematical problem-posing ability
Authors: Isrokatun I , Haryani C S , Rahmi N I
Published: April 2021

Problem-posing is the ability of students to raise the problem. Problem-posing ability is important, owned by students in mathematics. It is because integrative mathematics learning students need to do scientific activities. The scientific activities comprise observing, questioning, gathering information and communicating. By having problem-posing abilities, expected students to motivate to overcome the problems raised themselves. The purpose of this research analyze problem-posing ability in mathematics in third-grade students at the elementary school levels. The method used qualitative research using descriptive analysis. Here, problem-posing ability in third-grade students in mathematic is still low. It proved this by tests conducted in two elementary schools in Sumedang and got 37.7 and 42.5 scores. Based on the analysis of students’ answers, there are some difficulties experienced by students, namely unable to answer what they know, they cannot find the most important problems, they could not overcome the initial problems, and make questions. The indicators in problem-posing interrelated, that is looking for most important problem by making questions. It is because students will make questions based on the important information which they have already known. With this research, the teacher can easily determine the teaching method by the teacher to improve students’ problem-posing abilities.
3D Grapher application: Mathematical spatial ability
Authors: Kusnadi F N , Rachmawati T K , Syaf A H , Sugilar H
Published: April 2021

3D Grapher application is a user-friendly application that supports learning to three-dimensional geometry. The purpose of this study was to determine the increase of students’ mathematical spatial ability by using the 3D Grapher application. This study uses quasi-experiment method with a tutorial model conducted on class VIII students one of junior high school in Bandung City. The instruments research by test and the research data were analyzed by t-independenttest. Based on the results of research that improves mathematical spatial ability of students who get 3D Grapher based tutorial learning with an average n-gain score 0,56 better than students who get conventional learning with an average n-gain score 0,44. Thus learning through the 3D Grapher application can be used as an alternative to improve the mathematical spatial abilities.
Mathematical communications through project based learning based on android
Authors: Susilawati W
Published: April 2021

The lack of multimedia applications in schools and the low mathematical communication ability of students, as an alternative to using Android. The purpose of this research is to improve students’ mathematical communication ability through android based learning project. Using the quasi experimental method. This research conducted at Junior High School in Bandung with 55 students as samples, 29 students in class VIII C as an experimental class and 26 students in class VIII D as a control class. Mathematical communication ability test instrument. Data analysis: independent T test, two way ANOVA test. The findings: Improved communication of students who get learning on Android based learning projects was higher than students who get conventional learning. There were no difference in the achievement of mathematical communication between students who get an Android based learning project and conventional learning based on mathematical basic knowledge in the high, medium and low categories. There is the influence of the interaction between the type of project based learning with android applications and expository learning and prior knowledge mathematics category (high, medium, and low) on the ability of students’ mathematical communication. Android based learning project facilitates inventions process, reflective, the material is easy to understanding so that students’ mathematical communication skills increase.
Improving understanding of addition and subtraction concept in first grader through utilization of flipped classroom
Authors: Susilowati T , Rasmita R , Sumantri M S , Martini A
Published: April 2021

This class action research was conducted to see the effectiveness of the flipped classroom method on improving the concept of addition and subtraction. Flipped classroom method was chosen because it is in accordance with the current development of digital learning media that utilizes technology in learning. Flipped classroom performed by providing learning videos that can be viewed online by students at home then followed by problem solving activities through discussion activities in class with mentoring provided by the teacher. Based on this study an increase of 28.6% was obtained so that 83.3% of 42 students scored more than the minimum competencies criteria. The implications of this research can be utilized in other mathematical learning concepts.
Students’ problem solving on mathematical proportion
Authors: Sesanti N Y , Triwahyuningtyas D
Published: April 2021

This study analyzed problem solving abilities of the students on mathematical differential. Descriptive qualitative applied in this study with 26 students of secondary school; 16 males and 11 females. Data analysis reveals the ability of students’ problem solving abilities, namely understanding the problem, drawing up a problem solving plan, implementing the solution and re-checking the solution. The instruments used were test and interview. The findings showed that more than 50% mistake happened on drawing up a problem solving plan and re-checking the solution. So that to reduce the mistake we as lecturer should train the students in mathematical problem solving strategies.