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Biomass gasification technology is an attractive issue because its necessity has gradually increased amid many efforts to reduce fossil fuel consumption by total substitution or certain combination masses between fossil and biomass feedstock. In this research, catalytic testing was carried out on a bubbling fluidized bed gasification system using local bentonite from Pacitan, East Java – Indonesia as the bed particle. Silica sand was selected to get comparation performance since it is commonly used as bed material in fluidized bed gasification. The Umf values are 0,011 m/s and 0.031 m/s at a pressure difference (ΔP) of around 781 Pa. Gasification in the hot model system was taking place in superficial velocity into 4 Umf with the temperature at 700°C. Bentonite gave better fluidization stability, during sampling addition without significant agglomeration formation based on ΔP activities. The tar reduction was also more effective on bentonite compared to silica sand, shown by a decrement amount of tar that could be trapped in the tar capture system. The tar that was soluble on the acetone solvent in the cold trap sharply decreased becoming 52% from 186.33 g for silica sand to 89.49 g for bentonite application. [ABSTRACT FROM AUTHOR]

Let G be a finite graph having a vertex set V(G), an edge set E(G), and |E(G)| = q. An odd harmonious labeling of G is an injection f: V(G) → {0, 1, 2, ..., 2q − 1} such that the induced mapping f*: E(G) → {1,3,5, ... 2q − 1}, where f*(uv) = f(u) + f(v), is a bijection. If a graph can be labeled by an odd harmonious labeling, then the graph is said to be odd harmonious. A hedge graph Hn is a graph formed from series of n copies of 4 — cycle, C i = x i − 1 v i 1 x i v i 2 x i − 1 , i = 1,2, ..., n, and 2n vertices w i j , j = 1,2 by joining each v i j to w i j. A graph K′(2, nC4) is a graph formed from n copies of 4 — cycle C i = v i 1 u i 1 v i 2 u i 2 v i 1 , i = 1,2, ..., n two vertices, u 0 j j = 0,1 and 2n vertices w i j , by joining all vertices u i j to u 0 j and each vertex v i j to x i j. In this paper we show that hedge graph Hn and graph K′(2, nC4) are odd-harmonious. [ABSTRACT FROM AUTHOR]

This research aims to provide empirical evidence regarding the influence of governance, political connections, state ownership, and tunneling on the performance of Indonesian SOEs. The data is obtained from the annual report published by the SOE. The population used in this study were all Indonesian SOEs with an observation period of 7 years from 2014 - 2020, totaling 700 years of data. The 2014-2020 period was chosen because the Presidential NAWACITA implementation period began in 2014. The sample was determined using a purposive sampling technique where SOEs have complete financial reports from 2014 to 2020, and SOEs have carried out performance assessments with the KPKU. The data were analyzed using multiple linear regression with the help of the Minitab application. The results of this study conclude that governance has a significant positive effect, state ownership has a significant negative influence, and political connections and tunneling do not affect the performance of Indonesian SOEs. The novelty of this study is the use of the KPKU to measure the performance of SOEs. Suggestions for further research are to be able to explore further the impact of the pandemic on the performance of SOEs related to the variables used in this study, where several phenomena occur in the presence of a pandemic. The implications of this research can be input for the government as the majority shareholder of SOEs as well as regulators so that the policies taken related to SOEs can still be directed to improve the performance of SOEs in maintaining their existence and reducing inefficiencies related to the economic and social functions of SOEs. The limitation of this study is that several SOEs do not publish their annual reports, and this research has not been able to provide further descriptions of the impact of the pandemic while the data used is during the pandemic. [ABSTRACT FROM AUTHOR]

The Sikamaseang Integrative Child Social Welfare Service Center (PKSAI) is a child welfare program focusing on the prevention, risk reduction, and handling of children from violence, exploitation, neglect, and other mistreatment. The PKSAI program embodies Gowa Regent Regulation Number 35 of 2016. This program is located under the coordination of the Gowa Regency government through the Social Service, which forms a network of cooperation with several stakeholders. This research is motivated by the many social problems that occur in children, where there are around 113 cases recorded and cannot be resolved in the scope of the Gowa Regency. The goal and focus of the study in this research is the success of the Gowa Regency government in implementing PKSAI. The success of this network-based implementation is seen from three important aspects: rules of action, power relations, and actor strategies. As for answering the three aspects, the researcher uses qualitative research methods. The results showed that the policy network in implementing the Sikamaseang PKSAI program in the Gowa Regency had not been fully successful. [ABSTRACT FROM AUTHOR]

Science education is increasingly integrating elements from different disciplines to increase student understanding and engagement. One approach that is gaining increasing attention is the integration of STEAM (science, technology, engineering, arts, and mathematics) and design thinking. This combination combines scientific methods with creativity and innovation in the science learning process. This research aims to conduct a bibliometric analysis of scientific literature that discusses the integration of STEAM and design thinking in science education. Bibliometric methods will be used to identify key trends, patterns, and research contributions in this area. The results of this analysis provide an in-depth insight into developments and research directions in integrating STEAM and design thinking in science education. It is hoped that the implications of these findings will guide the development of more effective curricula and teaching practices in the context of modern science education. [ABSTRACT FROM AUTHOR]

Tooth brushing is a self-care daily activity that is easy to learn for normal children. Teaching tooth brushing to children with Autism Spectrum Disorder (ASD) need a special strategy since children with ASD have limitation in communication, language, and interaction. Children with ASD have a preference for learning with the visual method. The aim of this research is to explore the evidence base of structural-visual strategies in teaching tooth brushing in children with ASD. An electronic search was performed in 3 databases: PubMed, Cochrane, and PsycINFO. Two authors selected the articles, and the third author was involved in deciding eligible articles. A total of 31 publications were considered after the electronic search, 28 of which were included after removing 3 duplicate articles. Twelve articles were included after the title and abstract review, and finally, after reading the full text, 9 articles were included in this study. The study concludes that the structural-visual learning method is appropriate for teaching tooth brushing in children with ASD. [ABSTRACT FROM AUTHOR]

The form and dimensions of the maxillary and mandibular dental arches are essential in diagnosing and treating orthodontics. Factors including age, heredity, and hormonal changes during puberty impact how the jaws (maxilla and mandible) grow and develop. Also, one of the age ranges of children experiencing puberty is those aged 9 - 11 years. Therefore, this research's purpose is to make certain whether gender influences the dental arch's size in children aged 9 to 11 years. As the subject of this cross-sectional study, 108 children between the ages of 9 and 11 who fulfilled the inclusion criteria were categorized by gender. In each cohort, 54 pairs of dental study models representing 54 children were utilized. The dimensions of the dental arch were ascertained using digital sliding calipers, beginning at the midline between the right and left permanent central incisors and extending perpendicular to the inter-canines and inter-molars in the maxilla and mandible. MANOVA test exhibited p-values of < 0.05, indicating significant effects of gender on the dental arch's size. Hence, it can be concluded that there is an effect of gender on dental arch size at 9-11 years with normal nutritional status. [ABSTRACT FROM AUTHOR]

Drugs called bisphosphonates are used to treat metabolic abnormalities brought on by several types of cancer, including osteoporosis, bone disease and pain. Numerous studies have been conducted utilizing different kinds of bisphosphonates to promote anchoring and prevent tooth relapse in orthodontic treatment. Nevertheless, using bisphosphonates clinically can result in jaw osteonecrosis, which depends on the dose, duration, and dosage form applied. Hence, applying bisphosphonates as edible film strips (efs) is anticipated to prevent the negative effects. This literature review aims to explore the potential of bisphosphonate risedronate in the dosage form of efs to prevent tooth relapse. Efs is an alternative dosage form to help those with difficulties taking medications in bigger dosage forms. This form has drawn interest since, in contrast to synthetic preparations, it is non-toxic and can biodegrade naturally. Efs will be absorbed directly and enter the systemic circulation without going through hepatic first-pass metabolism and increases bioavailability, which will reduce the dose required to achieve the desired pharmacological effect, thereby reducing side effects and toxicity. In the oral cavity, this system works by dissolving the drug in the salivary fluid of the oral mucosa in a short time, thus providing a rapid release of the active ingredient. Patients after orthodontic treatment have the good dental condition and no longer require invasive procedures, such as tooth extraction which can trigger side effects of osteonecrosis of the jaw. Using bisphosphonate risedronate as edible film strips can potentially prevent relapse after orthodontic tooth movement and avoid side effects. [ABSTRACT FROM AUTHOR]

This study aims to determine students' mathematical literacy ability through an integrated enumeration module of Islamic values. This type of research is quantitative descriptive using a pre-experimental design. The research subjects were 26 students in the fifth grade of elementary schools in Palembang. This research was conducted in an elementary school in Palembang. The time used in this research is the odd semester of the 2021/2022 academic year. The test results showed that five high-ability students were able to write precisely and correctly what was known and asked about each item and formulate the problem into a mathematical model. They can design and use mathematical concepts well to solve problems correctly. Students can also interpret and conclude the results of the solution correctly. There are 15 students in the medium category. Most students can formulate problems by writing down things that are known and asked in each item and can apply the mathematical concepts used in solving and designing appropriate solving strategies but have yet to be able to interpret the final results. Meanwhile, six people in the low category needed help understanding the problem, so they could not design a solution strategy and solve the given situation. [ABSTRACT FROM AUTHOR]

The government has begun to develop Green Infrastructure in every stage of infrastructure development in the capital, especially in areas that often experience of floods. The application of green infrastructure with the concept of eco-drainage in the drainage system in the Kelapa Gading area is a hope for holistic benefits from an environmental perspective. This study aims to find a flood control model based on eco-drainage through a feedback system between all components in the flood control system and to find out the optimal scenario as the basis for recommending flood control policies. The analytical method of this research uses a dynamic system approach, which is a modeling method of a dynamic and complex system. by forming a certain scenario based on elements that interact with each other in the form of feedback or Causal Loop Diagrams. In this dynamic system, the problem will be seen as a whole based on the relationship between variables that influence each other. The development of a dynamic system model will be assisted using the Powersim Studio Version 10 software. The results of this study have revealed, based on the built model, that use of eco-drainage has benefits in groundwater conservation (S = 15.56), suppression of the rate of land subsidence (S = 1.001), and decrease the flood rates (s = 0.67). According to the simulation between the existing and moderate scenario, the moderate scenario is the best solution. This finding has important implication for the strategic policies implemented. The strategic is the policy of limiting the use of groundwater by 10%, the construction of 3500 eco-drainage points, and the use of polder infrastructure in Kelapa Gading with a pump capacity of 7 m3/s as many as 2 units. This study also has implication the optimal amount of eco-drainage depending on the saturated condition of the soil layer. [ABSTRACT FROM AUTHOR]

This study aims to analyze the TPACK of prospective physics teacher students in making physics learning videos. It uses descriptive methods. Student TPACK measurements are carried out through performance assessments in the form of learning videos and lesson plans. The TPACK assessment uses a questionnaire consisting of 34 items and is followed up with interviews. The research subjects were 18 third year physics teacher candidates at UIN Antasari Banjarmasin who took physics learning multimedia courses. The results showed that 16,7% of students had a high TPACK category, 61,1% in the medium category, and 22,2% in the low category. Technology Knowledge got the highest average (86.25) compared to other dimensions. It because students are familiar with technology. Meanwhile, Pedagogical Content Knowledge got the lowest average (79.56) because prospective physics teacher students had problems in the absence of interaction with students when teaching via video. Thus, it is necessary to have certain treatments to develop the ability of prospective physics teacher students in changing teaching methods in the form of videos. [ABSTRACT FROM AUTHOR]

One way to support the achievement of food self-sufficiency is to utilize the potential of existing domestic resources, for example, by using apple pomace as a raw material for pectin production. Imports meet the need for pectin due to Indonesia's absence of a pectin processing industry. So far, apple pomace has only been used as animal feed and biofuel, whereas in apple pomace, there are still many pectins that can replace the role of gelatin in the food industry. Pectin is a complex polysaccharide that composes plant cell walls, usually found in the middle lamella and the primary cell wall, which is bound to cellulose and hemicellulose. This study extracted pectin using live cells of Aspergillus niger and Trichoderma reesei through solid-state fermentation. The combination of the two microbes produces cellulase enzymes with the best composition. Ultrasound pretreatment was used to optimize the enzyme's penetration into the apple pomace's cell wall. This study was designed using one-factor-at-a-time (OFAT) optimization with three factors: the concentration of addition of molasses (0%, 6%, and 18%), the ratio of spores (1:1, 5:1, and 1:5), and the delay time of inoculation (0, 1, 2, and 3 days). The addition of 6% molasses concentration, spore ratio of T. reesei: A. niger of 5:1, two days delay time inoculation, and six-day fermentation obtained the optimum result in terms of the galacturonic acid content and yield, 43.38±0.29% and 14.52±0.48%, respectively. [ABSTRACT FROM AUTHOR]

Energy demand is increasing with the growth of the human population and the development of technology. In Indonesia, the supply of energy is dominated by fossil fuels which are not sustainable. To reduce the demand for fossil fuels, it is important to develop renewable energy technology and one of them is Biogas. Biogas can be produced from various biomass including Palm oil mill effluent (POME). The utilization of POME as raw material can potentially solve energy problems as well as environmental problems. Several studies have previously been done to produce biogas from POME, however, there is limited study on semi-continuous processes. Thus, in this study, the authors did an experiment to produce biogas from POME in a semicontinuous designed reactor and compared it with a batch process to evaluate and find a better condition to produce higher amount of biogas. In addition, biogas reactor discharge was analyzed and evaluated to be used as fertilizer. In this study, cow manure is used as starter. Biogas production started by preparing cow manure and water and set in the reactor until bubbles appeared in the slurry showing the presence of active microorganisms. The biogas production with a semi-continuous process was done by removing 1 L of biogas slurry from the reactor, then mixing 0.5L of the discharge with 0.5 of POME and recycling it every day. The result shows that the semi-continuous process gives a higher volume of biogas produced. In addition, there is only a small reduction in the number of N and K components after digestion that makes the biogas slurry discharge from POME is as potential as POME to be used as fertilizer. [ABSTRACT FROM AUTHOR]

Urinary tract infection (UTI) is one of most common bacterial infections in women. These infections cause uncomfortableness, morbidity, loss of work time and high cost for therapies. Gold standard examination for diagnosis of UTI is urine culture. Another common laboratory examination for UTI is urinalysis. Urinalysis is faster and easier to do than urine culture. To know how well the ability of urinalysis to detect UTI, urinary leukocytes, nitrite, and leukocyte esterase correlation with urine culture is assessed. This is an analytic observational study using a cross sectional design. Data was obtained from Laboratory Information System (LIS) Clinical Pathology and Microbiology Installation at Dr. Mohammad Hoesin General Hospital Palembang. The population consisted of all of UTI patients whose result of urinary leukocytes, nitrite, leukocyte esterase and urine culture. By using incidental sampling, 163 samples were collected, taken from 1st November 2015 until 31st January 2016 data period. The data was analyzed by descriptive and bivariate methods (Somers'd correlation) and presented in tables and narration. Urinary leukocytes, nitrite, and leukocyte esterase have a very significant correlation with urine culture (p<0.01). Urinary leukocytes have a weak correlation with urine culture (r = 0.295), urinary nitrite has a weak correlation (r = 0.391), and urinary leukocyte esterase has a weak correlation (r = 0.302). [ABSTRACT FROM AUTHOR]

Watersheds play important roles in providing daily necessities, irrigation, and fishponds. Unpredictable rain conditions and low rainfall have a drought-like effect on the surrounding environment. The purpose of this study is to determine the meteorological drought index's value and then compare it to the hydrological drought index, which is used to forecast future droughts. This study analyzed rainfall data for a period of 20 years, from 2001 to 2020. Drought analysis was conducted using two methods: the Standardized Precipitation Index (SPI) and the Hydrological Drought Index (HDI). The highest drought index at Location 1 was -2.47 in November 2009, while the highest drought index at Location 2 was -3.17 in January 2007. According to the HDI Method, the highest drought index occurs on average between July and October with a discharge value of 0 m3/sec, and an infinite HDI value results in the Very Extremely Dry criteria. According to the results of the comparison of the two methods, drought events frequently occur between July and October. [ABSTRACT FROM AUTHOR]

Urban planners often have a good vision for the urban environment, but that vision is usually limited to visual aesthetics. The sound-based qualitative perspective of the urban environment, which includes sonic and ecological diversity in urban design, is generally ignored. The soundscape approach can be the most effective system for application in urban planning. This paper aims to apply the soundscape approach to urban planning and explore the impact of sound on the formation of urban open spaces through a case study of the Surakarta City parks Indonesia. A mixture of quantitative and qualitative research methods was used. The quantitative method was used to measure background noise using a sound level meter and visualize with a surfer mapping software. The qualitative method was used to observe behavior, the physical environment and perception through interviews. In this context, the paper concludes that the concept of the soundscape is a well-established theme in acoustic environments to identify acoustic data that is compared with the human perception of the environment. Human perceptions of the natural environment and elements of natural sounds, as physical factors, can shape human settlements into a better living environment. [ABSTRACT FROM AUTHOR]

Maintaining visits can be an effective strategy for developing the tourism sector. The visitors will be word-of-mouth promoters for their relatives in their home countries who will likely be interesting to visit as well. This needs to be done by the South Lampung Regional Government to make plans to increase tourist visits, especially before the COVID-19-19 pandemic subsides. This study aims to develop a model for predicting the motives of revisit intention on several tourism objects in South Lampung based on: 1) visitor sociodemographic; and 2) accompanied by regional service performance strategies to increase revisit intention. The research was conducted in August-October 2020 on several tourist objects in South Lampung by conducting a field survey and the results were analyzed by regression modeling. Based on the model test, shows 1) the variables that affect revisit intention, namely gender, tourist domicile, ticket prices for tourist objects, tourist attraction facilities, and hospitality of service providers so; 2) to increase revisit intention, which is the key to the success tourism, tourism service providers and local governments need to improve services in the performance especially on hospitality services provider by conducting various training and counseling. [ABSTRACT FROM AUTHOR]

Innovative learning tools play an essential role in understanding mathematical concepts. However, there are still teachers who still need to exploit learning technologies fully. This study aims to determine the effectiveness of audiovisual Powtoon tools in teaching integer math. The population consists of all 1st semester SMP Negeri 5 Jepara class VII students for the 2022/2023 academic year, and the sample was drawn using a targeted sampling method. Data collection methods using tests, questionnaires, observation sheets, and interviews. The research method used is ADDIE, Incremental Analysis, Design, Development, Implementation, and Evaluation. However, this article only shows the implementation and evaluation steps. The results showed that (1) the completion rate of students in the experimental class was 90%, (2) the mean learning outcomes of the experimental class were better than those of the control class, and (3) there was an increase, as indicated by an N gains score of 0.76 in the High category From this it can be concluded that the audiovisual medium Powtoon is effective in learning mathematics throughout the material. [ABSTRACT FROM AUTHOR]

Green tea (GT), black tea (BT), and white tea (WT) are common tea which enjoyed immensely. The tea attributes include originality and chemical that are difficult to describe, evaluate and monitor. A traditional method of tea assessment has been sensory monitoring and evaluation, which lacks consistency and impartiality due to personal interest. To address these issues, visible and near-infrared (Vis-NIR) as a rapid, non-destructive, and simple methodology is developed to profiling and classify the GT, BT, and WT based on color and varieties. Vis-NIR spectroscopy with a 400–1,000 nm wavelength in original spectra and pre-processing analysis (SG-S, SG-1st, SNV, and MSC) were applied. Unsupervised analyses, such as Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA), were used in this research. PCA will lead the spectral information of the tea samples, which provides the grouping, classifying, and profiling. PCA result showed that the tea samples were grouped successfully. The dominant pattern shown at the spectral range of 600–700 nm was just corresponding to yellow or red. PLS-DA gave a reliable model, the Y-variables as predicted values were classified as y<1.5 of 1, 1.53.5. Model prediction of accuracy (ACC) was 100% on original spectra, SG-S, SNV, and MSC. Meanwhile, 91% on SG with nine samples were not classified. [ABSTRACT FROM AUTHOR]

One of Indonesia's efforts to solve health problems is to deal with neglected tropical diseases and water-borne diseases, one of which is dengue hemorrhagic fever (DHF). Every year cases of dengue fever have increased. In addition to considering the number of cases, the case fatality rate is also a measure of the severity of dengue cases. Central Java is the province with the first highest case fatality rate, whereas DHF cases in Central Java are the eight lowest in Indonesia. In order to reduce the mortality rate, the modeling of the factors causing DHF was carried out. Because the data on DHF cases is in the form of counts, the modeling method can use Poisson regression. However, because the variance is greater than the mean (overdispersion), the assumption is not fulfilled. Therefore, the mixed Poisson method is used, namely the Poisson Inverse Gaussian (PIG). Several studies have shown that the application of the PIG regression method produces higher accuracy compared to other regression methods such as Negative Binomial. Therefore, the application of the PIG regression method for DHF cases in Central Java is an innovation that provides more accurate and relevant results. Parameter estimation using Maximum Likelihood Estimation (MLE) method with hypothesis testing using Maximum Likelihood Ratio Test (MLRT). Based on data analysis conducted using R software, the altitude of the area significantly affects the number of dengue fever in Central Java in 2021 by 0,205. [ABSTRACT FROM AUTHOR]

The most crucial part of the process of learning mathematics is the understanding of concepts. However, there are still students who have a common understanding of mathematical concepts, especially in the material of straight-line equations. The common understanding of student concepts in the material of straight-line equations results in student learning outcomes not reaching learning completeness criteria. One of the efforts that will be made to improve students' understanding of concepts in the Straight Line Equation material is to utilize GeoGebra media. This article aims to determine the influence of GeoGebra media's use in improving students' understanding of concepts on the material of straight-line equations. This type of research is based on a quantitative approach with its research design, Classroom Action Research (CAR). The study subjects were 16 grade VIII students of Muhammadiyah 10 Andong JHS for the 2021/2022 academic year. This research uses data collection techniques and instruments in the form of Test Techniques and descriptive statistical analysis to describe the test of learning outcomes and student activities in the learning process using GeoGebra. [ABSTRACT FROM AUTHOR]

In informatics engineering major at Universitas Muhammadiyah Sorong, West Papua Indonesia, the study of the Numerical Method begins in fourth semester. In order to understand the definitions, concept, and algorithm involving such contents, students need to handle graphical and iteration representations. GeoGebra is possible tool to create different interactive that can be used as computing and teaching tools to illustrate math. In this article, visualisation of the fundamental concepts of numerical method are shown and study literature are strengthening the theory of numerical method. Moreover, this is emphasizing the iteration algorithm. These tools were used for the numerical method in non-linear equation. This study has aimed (1) the use of GeoGebra as digital technology for teaching Numerical Methods, (2) to make digital mathematics based GeoGebra for Non-linear Equations visualization, (3) to solve Non-linear Equations model based on GeoGebra. As the result, materials learning has been designed as a module, which can assist students in visualisation, iteration, and solve the non-linear equation problems. [ABSTRACT FROM AUTHOR]

This study aims to determine the cultivation of collaboration and problem-solving applied by students in learning activities. This type of research is descriptive qualitative. The subjects of this study were class VIII PK1 students of SMP Muhammadiyah 1 Surakarta totaling 16 students, and one of the mathematics teachers. Data collection techniques were used to test and interview techniques. The validity of the data is carried out by analyzing the test results that have been given. Data analysis techniques are carried out with stages 1) reviewing all the collected data, 2) studying the results of student work 3) concluding the data obtained. The analysis framework was developed based on the problem-solving category with Step Polya. The results of this study obtained that students at SMP Muhammadiyah 1 Surakarta have applied the collaboration method. Students still have difficulty solving mathematical problems, especially the material of straight-line equations. This happens because students are not used to solving questions using the Polya steps and, more often, by answering questions directly. [ABSTRACT FROM AUTHOR]

The aim of this study was to engage students in 21st century learning through the implementation of a Dilemma-Science, Technology, Engineering, Arts, and Mathematics (STEAM) teaching model. The Dilemma-STEAM teaching model integrates dilemma stories with problem solving tasks to support students' thinking and problem solving using the STEAM approach. Qualitative research was employed in three schools involving 25 students in a primary school and 60 students in two junior high schools. The data were collected through semi-structured interviews, reflective journals, and classroom observations. The students discussed a dilemma story about energy and thematic data analysis found that they solved problems and construct their understanding of STEAM concepts such as environmental car, oven, and hydroelectric power plants using a range of different strategies. In solving the problems, the activities helped the students to develop the 21st century skills of critical and creative thinking, and collaboration and communication skills. Finally, a dilemma-STEAM model enabled a multidisciplinary approach to be used in conducting science lessons to provide meaningful learning experiences for students. [ABSTRACT FROM AUTHOR]

This study aims to obtain and determine the secondary metabolite structure of the ethyl acetate fraction of Artocarpus champeden stem and its antioxidant activity using the DPPH method. Ethyl acetate fraction was fractionated using several chromatographic techniques. Data analysis results such as UV-Vis and 1H-NMR showed that the isolated compounds were flavanone derivatives, i.e., Artocarpanone (1), artocarpin (2), and kudraflavone C (3). Antioxidant assay of these isolated compounds using the DPPH method showed that all isolated compounds had a potent antioxidant activity with IC50 values were 99.3, 45, and 17.724 ppm, respectively. [ABSTRACT FROM AUTHOR]

This study aims to explore pre-service teachers' skills and knowledge in a 2-week Technological Pedagogical Content Knowledge (TPACK)-based training program. To achieve the goal, the reflective practice framework is employed in TPACK training with steps of Explore-Engage-Reflection-Transformation. The study employed a qualitative approach with data collection through interviews, reflective practice, and observation. The 30 participants engaged in the training are pre-service teachers (5 male; 25 female) at a public university in Indonesia. The training is provided by lecturers from New Zealand to provide different perspectives on TPACK components in pedagogy, technology, and subject matter. After the training in each topic, the pre-service teachers conducted reflection and envision their future roles. The next step is for them to implement what they have learned in school practices. The study found that the pre-service teachers developed a good understanding of ICT's role in the TPACK framework for creating meaningful learning experiences. They understand their roles as teachers in developing pedagogy and assessment for engaging students and empowering students' agency. Professional learning from the New Zealand education system was introduced within a holistic framework to stimulate students to be creative future-directed teachers and agents of change. The next step of the training is for the participants to inform the lecturers from New Zealand about their reflections and they how they will implement their learning from their TPACK design lessons. The future study will explore their reflections on the implementation of TPACK. [ABSTRACT FROM AUTHOR]

This study aimed to develop students' computational thinking skills by integrating Design Thinking with STEAM-PjBL. 41 students of a 10th-grade science class in SMAN 1 Rangkasbitung, Banten, Indonesia participated in the research. The study was conducted by utilizing various online platforms such as Zoom Meetings, Google Jamboard, and Edmodo. A qualitative method was used to collect data via interviews, observation, reflective journals, and a chemistry test. The five stages of Design Thinking were used throughout the research process: Empathize, Define, Ideate, Prototype, and Test [1]. The computational thinking skills were assessed using the four indicators developed by Guidry et al. (2014) of Decomposition, Algorithms, Data, and Abstraction. The result shows the computational thinking skill of the student achieved the categories of Problem Solving (level 4/Capestone); Troubleshooting Steps (level 4/Capestone); Relevant Solutions (level 3/Milestone), and Representation Through Technology (level 4/Capestone). Students are encouraged to solve contextual problems related to water pollution due to the use of detergents, as an application of the chemical concept of redox reactions in everyday life with the STEAM-PjBL approach. [ABSTRACT FROM AUTHOR]

The aim of this qualitative study was to analyze preservice chemistry teachers' competencies in designing STEM-TPACK learning during the COVID-19 pandemic. The research data were obtained from 34 preservice teachers learning chemistry through ICT courses in the 115 semesters at the State University of Jakarta. The study discusses the experience of preservice chemistry teachers in designing STEM-TPACK learning using Google. The design of this research is referred to as STEMQuest, which is the application of Webquests to the STEM-TPACK framework. This study resulted in five STEMQuests related to contextual chemical bonding which were then implemented in one school in Jakarta. STEMQuests can be used as resources, applications, and activities that can be developed and expanded to facilitate student learning in chemistry. Research data were obtained through observations, STEM-TPACK questionnaires, reflective journals, and interviews. The results show that the effect of STEM-TPACK, which consists of four elements; TPSK, TPMK, TPEK, and iSTEM, increases well after the STEMQuest design is completed. The preservice chemistry teachers also found that the STEMQuest design effectively achieved X-grade students' learning outcomes related to chemistry bonding concepts and STEM learning through engaging and meaningful learning experiences. [ABSTRACT FROM AUTHOR]

The aim of this study is to develop chemistry students' critical thinking skills using a STEM-Project-Based-Learning (STEM-PjBL) practice. Students developed soap and detergent waste treatment equipment to solve an environmental problem related to acid-base chemistry topics. Twenty-five grade 11 students at an Islamic boarding school in Banten Province, Indonesia, participated in this study. Qualitative methodology was used to gather data from a variety of sources such as classroom observation, interviews, reflective journals, and a critical thinking skills test. An analysis of students' critical thinking skills referred to the following five indicators: identify the question at issue, conceptual understanding, idea connections, assumptions, and inferences with five achievement levels. The study revealed that students reached a mastering and competent level, indicated by their ability to: ask questions and respond critically to a problem presented, use proper and adequate understanding of chemistry concepts, make connections between the issues encountered and the concepts studied; test assumptions accompanied by evidence; and deliver clear and logical conclusions. Therefore, the STEM-PjBL model can be considered an effective way for students to develop their critical thinking skills in chemistry and to support their active involvement in environmental education. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyze students' chemical literacy through implementing an Ethical Dilemma-STEAM teaching model in chemistry acid and base lessons. The model is designed to engage students in values-based learning through dilemma stories that pose environmental problems to be solved through the development of an interdisciplinary project. The study involved 40 grade 11 students from a high school in Jakarta, Indonesia, during the 2021/2022 academic year. A qualitative research method was employed to investigate students' learning experiences through classroom observations, semi-structured interviews, reflective journals, and a chemical literacy test. The model engaged students through five steps of learning: value reflection, problem-solving and decision-making, content integration, STEAM integration, and transformation. In this study students were challenged to develop a jet-powered boat as a solution to an inter-island mobility dilemma. The study found that the Ethical Dilemma-STEAM teaching model supported students' chemical literacy development. The study demonstrated that students were encouraged to think critically by applying their conceptual understanding to practice. They were motivated to look closely at chemistry issues in everyday life, an indication that this model could be used as an alternative way to engage students to see the relevance of chemistry concepts and their application to the local environment. The paper also addresses the difficulties researchers faced in implementing an innovative approach to chemistry education during multiple COVID-19 outbreaks. [ABSTRACT FROM AUTHOR]

This study aims to obtain a profile of students' perceptions of the learning environment through the Culturally Responsive Transformative Teaching (CRTT) approach carried out online in chemistry learning. The research was carried out in a high school in Jakarta in the even semester of the 2020/2021 academic year with 40 participants from class X science. This study uses qualitative methods with data collection techniques: interviews, observations, and reflective journals. They are collecting data related to aspects of the CRTT-based learning environment. Through this approach, students get new experiences that make them open-minded and show empathy to other students. Dimensions of the learning environment based on the results of the learning application with this approach, namely teacher support, student interaction and collaboration, response, access, and self-directedness. The profile of students' perceptions of the learning environment through this approach is through teacher support to form a comfortable classroom environment to increase students' learning ability. Learners who engage in meaningful discussions also tend to show better understanding, so this research positively impacts the learning environment and students' understanding of chemistry learning. [ABSTRACT FROM AUTHOR]

The spread of the Covid-19 virus has changed the social order and led to the emergence of a new era. One of the new habits that emerged is the use of video conferencing for meetings and learning. There are many alternatives to video conferencing that can be found today. This study aims to determine user preferences for video conferencing with criteria based on web equal 4.0. the method used is the Analytical Hierarchical Process (AHP) method with the help of super decision software, which is free and easy to use. Based on the results of this study, it was found that the highest criterion preference was for information criteria followed by interaction and usability. Based on criteria, Google meet is preferred by users, followed by BBB and Zoom. Based on the sensitivity analysis results, it can be concluded that the value of alternative preferences for criteria will not change, regardless of the value of the criteria. [ABSTRACT FROM AUTHOR]

This research involved the synthesis of the SnO2/MnO composites as photocatalysts for the degradation of methylene blue. The photodegradation process involved two variables including the effect of time and the initial concentration of the dye. Composites were made with a mass ratio of SnO2 to MnO at 1:0.02, 1:0.04 and 1:0.07 were characterized using XRD, SEM-EDS and UV-Vis DRS instruments. The results of XRD characterization of SnO2/MnO composites showed that the best mass ratio of SnO2/MnO composites is 1:0.07 with the formation of a typical peak at an angle of 2θ around 33° and a particle size of 14.43 nm. Furthermore, the energy bandgap value of the 1:0.07 SnO2/MnO composite obtained from the UV-Vis DRS characterization was 3.35 eV. The morphological character of the composite characterized using SEM showed a round shape with an uneven surface and elemental composition of Sn (51.96%), O (31.19%) and Mn (2.07%). From the instrumentation results, the composite was chosen as a photocatalyst to degrade methylene blue. The optimum conditions for photodegradation were obtained at a contact time of 180 minutes at pH 5, with percentage effectiveness of reducing the concentration of 83.4%. Meanwhile, for the effect of the initial dye concentration, the the largest percentage decrease is at 1 ppm, which is 63%. The results, therefore, showed that the SnO2/MnO composite was able to degrade methylene blue. [ABSTRACT FROM AUTHOR]

Nickel is a mineral commodity that plays an essential role in the metals trade. The demand for nickel worldwide trends to increase yearly, with a total reserve recorded at 89 million tons, and Indonesia currently has the highest nickel deposits. In addition, nickel production requires bulk energy for processing nickel ores, which would subsequently contribute to increasing Greenhouse gas (GHG) concentration in the atmosphere. This study aims to estimate the carbon intensity per ton product of nickel in Indonesia and to identify its main contributors. A nickel processing plant in Indonesia with a production capacity of 250,000 tons that uses RKEF technology was taken as a case study. The method for estimating the GHG emission is adapted from the Intergovernmental Panel on Climate Change (IPCC). The result of GHG Emissions is divided by the total product of nickel to generate the carbon intensity per ton of nickel product per year. The result showed that a total of 2.6 million tons of CO2-e per year was generated for nickel production. The total carbon intensity of nickel production was 10.5 ton CO2-e/ton nickel product generated by five areas: power plant, construction and engineering, processing plant, auxiliary, and transport logistic. The carbon intensity of nickel production in Indonesia appears to be in the range of carbon intensity of other nickel companies worldwide. In addition, hydrocarbon-based materials utilization such as coal and diesel fuel were found to be the main contributor to high GHG emissions. [ABSTRACT FROM AUTHOR]