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The study of curcumin degradation has been carried out by optimizing the effect of pH and solvents using the UV-Vis spectrophotometric method. The stability of curcumin decreased as pH increased. Curcumin was degraded rapidly in alkaline solutions. Curcumin has different maximum wavelengths in the different solvents. The UV spectrum of curcumin shifted as the pH increased. The UV spectra of curcumin shifted towards a smaller wavelength in alkaline solution. The shift in the UV spectra was due to curcumin degradation in an alkaline solution. In addition, Density functional Theory (DFT) calculation was carried out to simulate the curcumin and its degradation product ground states and excited states. The absorption spectra calculated using the TDDFT method showed that the maximum wavelength of curcumin and its degradation products agreed with the experimental data. [ABSTRACT FROM AUTHOR]

Solid Polymer Electrolyte (SPE) has been made by the solution casting method. SPE consists of PVA as host polymer mixed with chitosan (CS) biopolymer, NaClO4 as salt, and SiO2 synthesized from bagasse ash as a filler to increasethe ionic conductivity of the electrolyte system. Using chitosan biopolymer and SiO2 filler from bagasse ash to obtain environmentally friendly SPE, reduce waste problems, and lower production costs. The use of NaClO4 salt as a source of sodium ions and the addition of fillers is done so that the crystallinity of the polymer is reduced and high ionic conductivityis obtained. In this study, a thin SPE film was produced that was not easily torn. XRD test results showed a decreased crystallinity after the addition of NaClO4 salt and SiO2 filler. The FTIR spectra showed that NaClO4 binds to the polymer and SiO2 acts as a filler only. From the characterization results, it was concluded that the addition of NaClO4 and SiO2 salts as fillers could increase the ionic conductivity of the electrolyte system. The maximum ionic conductivity of 3.00×10−4 S cm-1 at room temperature is obtained from the ratio of PVA:CS:NaClO4 (3:2:4) and 5% SiO2. [ABSTRACT FROM AUTHOR]

Indonesia has an average wind speed above 4-6 m/s. Based on these conditions, Indonesia has not maximized using wind energy as an electricity generator. This study aims to analyze the performance of a generator windmill with the Dynamo Torch that can convert energy, identify the LED lights that are connected to the generator due to the motion of the windmill, and make recommendations for designing a generator windmill with the Dynamo Torch as a STEAM learning medium. This research uses the Research and Development (R&D) method, which produces a prototype. Manipulate the size of the windmill and fan speed by controlling the components used in the prototype. The research results obtained are windmill generators with Dynamo Torch that can convert wind energy through mechanical energy into electrical energy. The windmill can move with a wind source from a fan and rotating algae. Propeller 1, which has a smaller size (8 cm), can light up the LED brighter than propeller 2 (9 cm). Designing a generator windmill with the Dynamo Torch as a STEAM learning medium can be used as an effort to provide students with an understanding of energy conversion. In further research, we can develop the application of other material concepts to physics learning using STEAM media. Apart from energy conversion, there is a connection between global warming solutions, wind power generator prototypes, and the application of electromagnetic induction materials. [ABSTRACT FROM AUTHOR]

21st-century learning in Indonesia emphasizes 4C skills for students. The Merdeka curriculum integrates Pancasila characters with local culture, while ethnoscience and ethno-physics learning combine community beliefs with scientific knowledge. This research examines the validity, reliability, and DIF of ethno-physics test instruments using Rasch analysis to identify gender bias and student domicile. The research examines the impact of gender and domicile bias on students' responses to an ethnophysics test at a public senior high school in Madura, Indonesia. The research involved 36 native Madurese students familiar with Kerapan Sapi culture. Results showed that 95% of items did not contain bias, with five biases in indicators at item number 3 and 4. The research found no bias from village, city, or male and female student groups. [ABSTRACT FROM AUTHOR]

Local wisdom is a tradition or habit passed down by a group of people in the past and arises from a strong understanding of the surrounding environment. Heaven fire is a local wisdom that can be used as a medium for understanding physics concepts for students to make them easier to understand. Heaven fire occurs because of a burst of natural gas from the ground, which is ignited by fire until it burns and does not go out even when it rains. Methods This research was conducted qualitatively with data collection techniques through interviews and literature. Based on the analysis of the data that has been done, it is found that making Heaven Fire a tourist spot is an effective conservation effort by the conditions and capabilities of the surrounding community. In the phenomenon of heaven fire, there is a concept of physics, namely the concept of heat that causes the black body radiation and piezoelectric. Black body radiation is seen on a rock around the fire, the fire of heaven fire makes the temperature of the rock increase and makes it glow or emit an electromagnetic wave. Different temperatures of a rock emit different wavelengths of electromagnetic waves. The other physical phenomenon of Heaven fire is piezoelectric, which is an electric phenomenon that has the most probability of causing Heaven fire. It can make a spark because of pressure, and that spark is the first fire of heaven fire. [ABSTRACT FROM AUTHOR]

This research aims to develop physics learning media that integrate local wisdom in schools or communities and analyze the ethnoscience concept of Ancak Robyong. The research method used in this research is a qualitative approach. In addition, there is a literature study of journal sources, books, writings related to the problem, observation, and interviews. The results of this study are the analysis of physics concepts in the local wisdom activities starting from the process of making Ancak Robyong there is the concept of equilibrium, the lifting process there is the concept of the Newton First Law, the process of carrying there is the concept of equilibrium of a rigid body, the shaking process there is the concept of the Newton Third Law, the arak-arak process there is the concept of effort which is the movement from one place to another and the reflection of Ancak Robyong colour to know the process of reflecting light so that residents can see the beauty of Ancak Robyong. Thus, the local wisdom of Ancak Robyong is used as a learning medium, especially in Physics, to improve science-physics knowledge (Ethnophysics) into real scientific knowledge. [ABSTRACT FROM AUTHOR]

Indonesia is a multicultural country with various local wisdom that can be integrated into physics learning. The purpose of this study is (1) to Analyze the distribution of Indonesian local wisdom in physics learning research, (2) to Analyze the research network and visualization of Indonesian local wisdom in physics learning research, and the contribution of local wisdom in physics learning (3) Analyze author collaboration and top counties Indonesian local wisdom in physics learning research. The bibliometric analysis uses VOSviewer with Scopus database in the 1986-2023 period. The result showed that researchers are more interested in publishing their articles at international conferences. The most chosen conferences and journals are UPINCASE 2020 and JPCS, with the most publishers being IoP Publishing and the most productive authors being Kuswanto H. and Misbah M. Research trends related to Indonesian local wisdom in physics learning increased in 2017-2020 the number of publications and the highest number of citations in 2017 and 2019 with articles that were trending from Indonesian authors "The development of physics teaching materials based on local wisdom to train Saraba Kawa characters." The integration of local wisdom of physics learning can be divided into three parts: content, learning material, and learning media. Author collaboration about physics and local wisdom can be divided into 5 clusters, and Indonesia is the most productive country in publishing documents. The recommended research about physics local wisdom is the content survey about cultural value in local wisdom. [ABSTRACT FROM AUTHOR]

In Indonesia, many regions have traditions that are called customs or local wisdom. This study aims to analyse the concept of fluid physics in the Javanese local wisdom tradition known as "Larung Sembonyo". It is a community tradition that is carried out as an expression of gratitude, a request for smooth farming and abundant marine products. The concept of fluid physics that dominates in this tradition is Archimedes' law. Besides that, other concepts that support the course of this tradition are sea waves, effort, and energy. The method used in this research is descriptive with a qualitative approach. The analysis was carried out by identifying the concepts of fluid physics contained in Larung Sembonyo and explaining the relationship between these physics concepts and aspects of tradition. Relevant physics concepts include the buoyant force that keeps the boat afloat on the surface of the water, boat motion that is affected by water currents, and boat stability in preventing overturning or overturning during the launching process. This understanding can help appreciate aspects of physics in local wisdom traditions and relate them to more general physics knowledge. This research can also provide new insights into how physics concepts are applied in the context of local culture and traditions. [ABSTRACT FROM AUTHOR]

This research aims to utilize robotics technology to create an Arduino-based automatic trash can innovation with an infrared sensor that integrates STEAM learning based on problems in the surrounding environment during the Covid-19 pandemic. This study follows the research procedure of the Research and Development (R&D) model. The innovations made in this automatic trash can include being able to open and close automatically, being able to find out the capacity of the remaining trash can, and being able to provide feedback in the form of thanks for the efforts of the community who have disposed of their trash in the right place. The innovation of making automatic trash cans that are integrated with the STEAM approach can be used as alternative learning that can improve students' critical, creative, and logical thinking skills and scientific work and can trigger students' enthusiasm to be able to continue to innovate in solving problems in the surrounding environment. In addition, with the innovation of the automatic trash can, it is hoped that it can inspire and educate the public to dispose of waste according to the place provided. [ABSTRACT FROM AUTHOR]

This research aims to determine students' learning difficulties in the concept of statistical electricity through descriptions of problems. Participants were 89 first-year physics students taking the Basic Physics II course. Students complete 14 reasoned multiple-choice questions to measure their understanding of the concept. The results of students' work are analyzed by determining statistics on students' concept understanding scores and supporting data in the form of answers to students' reasons to explore students' difficulties in answering questions. Based on the results, it was found that there were still many students who had trouble understanding the concept of statistical electricity. Students' conceptual understanding still needs to improve in line with the average score. The solution that was found needed clarification when comparing the electrostatic force between two charges with different charge sizes due to students' incomplete knowledge, namely by not using Newton's third law. Another solution is to determine electrostatic forces and electric fields, causing students' learning in applying vector concepts, namely vector quantities, to be still not good. These findings are the basis that in understanding the concept of fluid statistics, related concepts need to be given so that students are able to view physics as a single unit. [ABSTRACT FROM AUTHOR]

This study aimed to develop sound resonance measuring tools for an Android-based Sound Level Meter as an innovation in physics experimental tools in learning. This tool is designed to facilitate students' understanding of sound waves and sound resonance through interactive experiments. The resonance tube is the main component combined with the SLM Android microphone, sound system, wireless probe, and audio generator. This study evaluates the feasibility of the device through practical trials, which involve measuring the frequency and intensity of sound in a resonant tube. Practicum results data show that there is a significant increase in sound intensity along with an increase in frequency. This is consistent with the theory that frequency and intensity are directly proportional. However, the measurement results are also affected by factors such as the cross-sectional area of the resonant tube, the amplitude, and the material used. Based on this feasibility test, the SLM Android-based sound resonance tube measuring instrument was declared ready to be used in school physics learning. Thus, the SLM Android-based resonant tube measuring instrument is expected to increase the effectiveness of physics learning and provide a more exciting learning experience for students at school. [ABSTRACT FROM AUTHOR]

Over time, the use of fossil energy in everyday life is increasing. One effort can be made to replace fossil fuels with other renewable fuels, such as solar energy. The STEAM integrated solar panel fan development aims to analyze the STEAM concept in solar panel fans, analyze solar panel fans to reduce the use of fossil fuels and analyze the fan propeller speed obtained from the solar panels used. The research used the ADDIE Model and literature studies from Google Scholar and other journals. The trial was carried out at the researcher's house by manipulating the weather, time of day, and the magnitude of sunlight. Based on the research, it was found that the STEAM integrated solar panel fan can be used properly. Fans using energy sources from sunlight can reduce the consumption of fossil fuels and are environmentally friendly. The speed of the fan blades constantly changes based on weather conditions and time of use. Fans can work optimally in sunny weather and high magnitudes of sunlight, usually during the day. [ABSTRACT FROM AUTHOR]

STEAM educational projects foster 21st-century skills. Integrating STEAM technologies into public school curriculums can engage students, develop laboratory skills, and establish STEAM pedagogy in the classroom. The prototype kit led with mode MCU ESP 8266 sensor is a technology that already uses the ability to transfer data over a network without requiring human-to-human interaction. This prototype uses ESP 8266 MCU mode, project board, red LED lights, jumper cables, 100Ω resistors, and micro-USB cables. Programming is carried out on the Arduino application, where data is transmitted to the mode MCU ESP 8266. A bright red LED indicates the success of the circuit. This series can represent high school physics material, namely dynamic electricity taught in class XII. [ABSTRACT FROM AUTHOR]

The objective of this research is to design a Savonius wind turbine with a horizontal axis optimized for low wind speeds and to measure the power output and efficiency generated by the turbine. The research methodology employed in this study is experimental. The turbine design incorporates 0.3 mm thick transparent PVC as the material for the turbine blades, with a configuration featuring three helical-shaped blades measuring 93 cm in length, 16 cm in width, and having an 8 cm radius. The turbine frame is constructed using 20 mm×20 mm aluminum profiles, with dimensions of 100 cm in length, 30 cm in width, and 35 cm in height. Data collection involves conducting 10 repetitions for each wind speed variation ranging from 1 m/s to 10 m/s. The highest power output increase occurred at a wind speed of 6 m/s, with a power of 0.46 Watt increasing by 0.13 Watt. It resulted in an average shaft rotation of 132.28 rpm, average power output of 0.27 Watt, and average efficiency of 7.10% for wind speed variations ranging from 2 m/s to 6 m/s. [ABSTRACT FROM AUTHOR]

The aims of this study are to describe how the interest of biology teacher students towards the use of three-dimensional software in the study of plant anatomy courses and see how the relationship between 3D representation using software and learning outcomes that have been done in the process of learning plant anatomy courses. This research uses quantitative methods with an associative and descriptive approach. Associative data analysis is conducted between 3D representation using blender software with the learning results of prospective biology teachers, to descriptively by analyzing the results of students' interest in biology teachers on learning using three-dimensional software. Sampling was done by purposive sampling by looking at the completeness of instrument data obtained by 63 students of prospective biology teachers. The instruments used are 3D representation scores, learning score and interest questionnaires. The results showed a strong relationship between 3D representation of learning outcomes, with a correlation coefficient value of 0.74, the relationship obtained was also significant. For the highest interest in student learning, it is about student activities, because students feel that they make their own 3D representations, often ask questions, and always follow the learning well. [ABSTRACT FROM AUTHOR]

The local wisdom of Karapan sapi is the original culture of the land of Madura, which can make it easier for students to learn and accept and understand the physics material presented, so that there is a potential in its development which is then studied in this study. The purpose of this research is to analyse the potensial of developing a local wisdom of Madura karapan sapi as teaching material in supporting physics learning. The type of research used is descriptive qualitative research using literature studies and bibliometric analysis. The research was conducted by studying literature, with the object of research is the local wisdom of Madura in the form of karapan sapi. The application of local wisdom in learning can be carried out by developing a teaching material to assist the implementation of learning. From the bibliometric data obtained, it is known that local wisdom is related to learning. Karapan sapi which is a local wisdom has the potential to be integrated with learning. There is a potential in developing teaching materials based on local wisdom of Madura cow karapan to be applied in physics learning. [ABSTRACT FROM AUTHOR]

In the current study, gold nanoparticles (AuNPs) were prepared using an electrochemical synthesis method. The effect of electrolysis potential on the absorption value of gold nanoparticles and their stability time has been studied. The first step is to determine the maximum wavelength of synthesized AuNPs in the wavelength range of 300 to 800 nm and the maximum absorbance value was obtained. The electrolysis potential variations used in this study were 50, 53 and 55 Volts. The stability time of the synthesized gold nanoparticles was studied by observing the absorbance value on measurement days 1, 2, 3 to day 20. The results showed that the maximum wavelength of the synthesized AuNPs was 525nm with an absorbance value of 0,626 A. The maximum gold nanoparticles absorbance was obtained at the electrolysis potential of 55 Volts. The absorption of gold nanoparticles showed almost the same value at a wavelength of 526nm during the observation period of 20 days. [ABSTRACT FROM AUTHOR]

Ammonia was known as a chemical marker that can be found in the urine of patients with chronic kidney disease. The ammonia detection, usually, based on spectrophotometric method that require sample preparation such as derivatization which was complex and time-consuming. Chromatographic method was very accurate, but the investment and operation of this method was relatively expensive. Therefore, research to detects ammonia using gas sensor array in two types of testing: qualitatively and quantitatively, was carried out. This study emphasizes that the combination of sensor array with cross selective and cross sensitive characteristics, namely MQ-3, MQ-4, MQ-6, and MQ-8 sensors, capable to qualitatively and quantitatively to determine ammonia. In the qualitative test, the research was carried out by injecting 100 µL of ammonia, acetone, ethanol, and acetic acid in a gas sensor array chamber with 10 replications. Clustering analysis such as Principal Component Analysis (PCA) and K-Means Clustering, shows that gas sensor array can distinguish ammonia from the other test compounds. The quantitative analysis was done by injecting ammonia : distilled water in four different ratios i.e., 25%, 50%, 75%, and 100% as much as 100 µL with 5 replications. PCA, Agglomerative Clustering, and Decision Tree Classifier show that the sensor array can detect the ammonia based on their ratio accurately. [ABSTRACT FROM AUTHOR]

Plasma nitriding and plasma nitrocarburizing are thermochemical processes used to increase the surface hardness of materials without significantly reducing toughness. This work investigated the increase in surface hardness of commercially pure titanium due to plasma nitriding and plasma nitrocarburizing processes and compared them. Plasma nitriding and nitrocarburizing processes were carried out at temperatures of 350 °C and 450 °C for 2, 3, 4, and 5 hours. The hardness of untreated commercially pure titanium was 105.75 VHN. The maximum hardness achieved in this research for the nitriding process was 227.46 VHN while for the plasma nitrocarburizing process it was 312.68 VHN. It could be concluded from this research that plasma nitriding and plasma nitrocarburizing could increase the hardness of commercially pure titanium. The hardness value achieved by the plasma nitrocarburizing process was higher than that of plasma nitriding. [ABSTRACT FROM AUTHOR]

From the general people perspective, sunrise and sunset are often associated with myths that have been rooted in society. The research aims to scientifically discuss the colour differences of the sky due to the apparent daily movement of the Sun. The discussion is related to the concept of Rayleigh Scattering, scattering of electromagnetic waves from Sun by the Earth's atmosphere, using Photovoice techniques. The data was taken by taking pictures and analyzed by photovoice technique using various scientific sources. In the studies discussed in the article, the object used is photos of sky conditions at sunrise, during the day, and at sunset. The phenomena of the apparent daily motion of the Sun, which results in the transition of day and night, makes the colour of the sky appear different. These events occur due to the scattering of white light radiated by the Sun by particles of the Earth's atmosphere. At dusk, the scattered light will pass through a further away path than during the day. This phenomenon causes the scattered light to be a large wavelength, namely red and orange. The blue colour does not appear at dusk because it has been scattered in areas that experience daylight. [ABSTRACT FROM AUTHOR]

Monitoring the activities of the surrounding area using a wireless sensor network is very important to help support human work such as bridge surveillance, agricultural supervision, and others. Wireless sensor networks work in real time requiring a large amount of power source. In order for the wireless sensor network to work optimally and last, it is necessary to minimize the working energy of communication protocols on wireless sensor networks as in this study is a link layer protocol used for savings in the use of resources in wireless sensor network transmission systems. In large-scale use, wireless sensor networks use multiple nodes. In order to use less energy for the most efficient use of wireless sensor networks with many nodes, the most appropriate way to perform a clustering system that divides nodes into groups with each cluster there is a head cluster that serves as a data aggregation in each node member on their respective clusters. In this study the clustering system used the LEACH protocol. If a wireless sensor network uses multiple nodes, it is vulnerable to attack. To provide security in the wireless sensor network used Tiny Sec protocol based Tiny OS. So in performing energy minimization wireless sensor network protocol can also consider the security aspects of the sensor network. The parameters analyzed in this study are the relationship of the use of working energy with the lifetime of the sensor network. The data found in this study is with the addition of Tiny Sec, the power consumption and data used become minimal and the working energy that is able to survive by using 100 nodes and working energy 2 J then the maximum usage time is about 500 seconds. [ABSTRACT FROM AUTHOR]

Torrance Test Creative Thinking (TTCT) figural form was developed to measure creativity based on Guilford's theory. This test measures fluency, flexibility, originality, and elaboration scales. The state-of-the-art assessment involves a human rater to judge respondent responses to creative thinking tests. Such a judging process is time-consuming and subjective preferences. We, therefore, propose a novel assessment of creative thinking to address the issues, partially for elaboration scales. Elaboration scale is the ability to detail and deepen initial ideas which increase their complexity and improves presentation. In image analysis, this scale is determined by estimating the number of objects in an image. The Maximum Excess over Sub Array (MESA) distance predicts image density values by estimating low-level features and sharing the advantages of general regression-based methods, while also maintaining location information. The maximum counting error performs all rectangular subregions as a learning objective function. The result statistically confirmed that the proposed method has no significant difference from human rater judging. In other words, the proposed method is reasonable to judge respondent responses to the creative thinking test. [ABSTRACT FROM AUTHOR]

Online learning has become a new trend during the Covid-19 pandemic. These affect a lot of the students. The viewpoints of students from the Electrical Engineering Department (JTE) Universitas Negeri Surabaya (Unesa) are important to increase the quality of online learning in the future. The purpose of this research is to find out the students' viewpoint regarding (1) online learning that has been running; (2) Eligibility of online learning to continue after the covid-19 pandemic; (3) Student opinion for the improvement of online learning in the future. The method used in this research is descriptive qualitative, by distributing questionnaires. The total respondents of this research are 90 students from JTE. The results of this study indicate that JTE students are satisfied with the online learning that has been carried out. Therefore, they hope to continue this even though the covid-19 pandemic is over. In conclusion, online learning in JTE has been good even though there are various opinions for future improvements. [ABSTRACT FROM AUTHOR]

This study aims to obtain information about the interaction between the use of learning models and work motivation on the competence of knowledge, attitude, and skill in Programmable Logic Control Subject. The research conducted at this Vocational High School is an experimental research using the "Non Equivalent Control Group Design" research design, which involves two research subject, namely: (1) Class XI Electrical Power Installation Engineering Expertise Program-1 (taught by using a learning model). Based on problem); and (2) Class XI Electrical Power Installation Engineering Expertise Program-2 (taught by using the direct learning model). The study found: (1) there is a significant interaction between the use of learning models and work motivation on knowledge competence in Programmable Logic Control Subjects in Vocational High Schools, (Fcount=21.261 with a significance level of 0.000 <0.05); (2) there is a significant interaction between the use of learning models and work motivation on attitude competence in Programmable Logic Control Subjects in Vocational High Schools (Fcount=8.902 with a significance level of 0.004 <0.05); and (3) there is a significant interaction between the use of learning models and work motivation on skill competencies in Programmable Logic Control Subjects in Vocational High Schools (Fcount=9.206 with a significance level of 0.004 <0.05). [ABSTRACT FROM AUTHOR]

This study aims to describe the mathematical literacy ability of junior high school students in solving PISA questions. The type of research used is descriptive with a quantitative approach. The research was conducted on the eighth-grade students of SMPN 10 Madiun as many as 28 students. Collecting data using PISA test questions to determine students' mathematical literacy skills. The indicators of mathematical literacy in this study refer to aspects of content, context, process, and level of PISA. The results showed that the mathematical literacy ability of junior high school students in solving PISA questions in the content aspect was included in the sufficient category with an average score of 56.65, the context aspect was included in the sufficient category with an average score of 55.22, and the process aspect was included in the enough with an average value of 47.02. The mathematical literacy ability of junior high school students at the PISA level is included in the sufficient category with an average score of 54.56. [ABSTRACT FROM AUTHOR]

Commercially pure titanium has excellent hardness and wear resistance. However, if commercially pure titanium is utilized as a friction component, hardness and wear resistance must be increased. The goal of this research is to improve the surface hardness and wear resistance of commercially pure titanium. Plasma Nitriding was carried out on commercially pure titanium with temperature variations of 350 oC and 450 oC. While the process durations were 2, 3, 4, and 5 hours, respectively. On untreated and plasma nitrided commercially pure titanium, hardness testing with a Vickers hardness tester, wear testing with an Ogoshi High-Speed Universal Wear Testing Machine, metallographic observations with a Scanning Electron Microscope, and composition testing with the X-Ray Diffraction method was performed. Hardness test on plasma nitrided commercially pure titanium at 350 oC with process durations of 2, 3, 4, and 5 hours resulted in surface hardness of 135.84 VHN, 156.54 VHN, 171.34 VHN, and 179.86 VHN, respectively. In the same way, the hardness test on plasma nitrided commercially pure titanium at a temperature of 450 °C with a process duration of 2, 3, 4, and 5 hours resulted in surface hardness of 149.52 VHN, 183.16 VHN, 227.46 VHN, and 193.64 VHN, respectively. The results of the wear test on the untreated and plasma nitrided commercially pure titanium at a temperature of 450 oC showed a wear value of 4.0148 × 10−8 mm²/kg and 7.89 × 10−9 mm²/kg. The metallographic test showed the formation of a thin layer with a thickness of 1.09 µm. X-Ray Diffraction test showed that this thin layer was formed from Titanium Nitride compound. Based on the findings of this investigation, it was established that plasma nitriding might improve the surface hardness and wear resistance of commercially pure titanium. [ABSTRACT FROM AUTHOR]

Plasma nitrocarburizing is a surface hardening method by depositing nitrogen ions and carbon ions on the material's surface to form a hard nitride and carbide phase. This research was aimed to determine the plasma nitrocarburizing's effect on the surface hardness and surface roughness of commercially pure titanium. Phases present in untreated commercially pure titanium were observed with an optical microscope. Then the plasma nitrocarburizing process was performed on commercially pure titanium at an elevated temperature of 450 oC and process duration 4 hours. Surface hardness on untreated and plasma nitrocarburized commercially pure titanium was tested with a micro-Vickers tester. Meanwhile, the surface roughness test was carried out before and after the plasma nitrocarburizing process. The thickness of the thin film was observed with a Scanning Electron Microscope. X-Ray Diffraction Testing was applied to determine the compounds formed on a thin layer. Metallographic testing with an optical microscope showed that the material had only phases α. A thin layer thickness of 1.88 µm was observed with a Scanning Electron Microscope. This thin layer was known to be formed from titanium nitride (TiN) and titanium carbide (TiC) compounds based on the results of X-Ray Diffraction testing. The surface hardness of untreated and plasma nitrocarburized were 105.75 VHN and 312.68 VHN, respectively. The surface roughness of untreated and plasma nitrocarburized were 0.11 Ra and 0.13 Ra, respectively. According to the findings of this study, the plasma nitrocarburizing process increased the surface hardness and surface roughness of commercially pure titanium. [ABSTRACT FROM AUTHOR]

The community who lived around Sipakario Beach, Nipah-Nipah Village were affected by the tourism development in the area. This research examined if the environmental carrying capacity including the natural and socio- physical environment affected the welfare of the community living around Sipakario Beach, Nipah-Nipah Village, Penajam District, North Penajam Paser Regency which area was developed for tourism purposes. In this research, 100 local people participated as samples. The validity of the research instrument was tested using the product moment correlation test, while the reliability was measured using the Cronbach's alpha formula. The data of this research were analyzed in multiple regression analysis. The results showed that community welfare was affected by the environmental carrying capacity which includes natural physical environment and the socio-physical environment. [ABSTRACT FROM AUTHOR]

When used as a friction-prone component, commercially pure titanium must be hardened. Plasma nitrocarburizing can increase the hardness of commercially pure titanium. N2 and CH4 gases are used as nitrogen and carbon ion sources in plasma nitrocarburizing. The objective of this work is to investigate how the ratio of N2 to CH4 gas flow rates affects the thickness and hardness of the thin layer created. At a pressure of 1.6 mbar and a temperature of 450 oC, plasma nitrocarburizing was carried out for 4 hours with different gas flow rate ratios of 1:1, 1:2, 1:3, and 1:4. To analyze the microstructure and surface composition of the material, a metallographic test was performed using a ZEISS EVO Scanning Electron Microscope-Energy Dispersive Spectrometry. To determine the compounds formed, a composition test was conducted using X-ray Diffraction (XRD) with the brand Pw3040 60 X Pert Pro Mpd Diffractometer. The Matsuzawa MMT-X7 Micro Vickers Hardness tester was used to measure surface hardness. Hardness testing on commercially pure titanium nitrocarburized plasma with variations in gas flow rate ratios of 1:1, 1:2, 1:3, and 1:4 resulted in hardness of 312.68 VHN, 134.96 VHN, 111.56 VHN, 109.3 VHN, respectively. The metallographic test by using Scanning Electron Microscope results showed the formation of a thin layer. The thicknesses were 1.88 µm, 1.69 µm, 1.65 µm, and 1.44 µm. This thin layer was confirmed by a composition test formed from TiN and TiC compounds. The plasma nitrocarburizing technique increased the hardness of commercially pure titanium, according to the test results, however, when the flow rate of CH4 was increased by a ratio of 1:2, 1:3, and 1:4, there was a decrease in hardness compared to a ratio of 1:1. Plasma nitrocarburized commercially pure titanium has the potential to be used in the medical field as a material for hip joint arthroplasty. [ABSTRACT FROM AUTHOR]

The silica nanoparticles have been successfully synthesized from sugarcane bagasse using the sol-gel method. Sugarcane bagasse contains abundant silica, so it can used as an alternative source of silica nanoparticles. Sugarcane bagasse was calcined at 650 °C for 2 hours, then it was extracted using NaOH to obtain sodium silicate solution. The solution was titrated with HCl for gelling process. The synthesized of silica nanoparticles from sugarcane bagasse were characterized using FTIR and XRD. Based on the XRD characterization, the results showed that the silica had an amorphous phase, and the FTIR spectra has siloxane and silanol groups. The synthesized silica nanoparticles have an average size of 53 nm which was calculated using Scherrer Formula. From the data obtained, sugarcane bagasse can used as a source of silica nanoparticles. [ABSTRACT FROM AUTHOR]

Wheat production in Indonesia is still low and has not been able to meet the needs of the community. Fertilization is an activity of providing organic and inorganic materials into the soil to replace nutrient losses from the soil, while the provision of seeds per hole can determine the right plant population. The purpose of this study was to determine the effect of the type of fertilizer and the number of seeds per hill on increasing the production of wheat (Triticum aestivum L.) Dewata 162 varieties. This research used a factorial experiment (4 x 2) arranged in a completely randomized block design and repeated three times. The first factors are the kind of fertilizer (cow manure, chicken manure, goat manure, and NPK); the second factors are the number of seeds per hill (one seed and two seeds per planting hill). The results exhibited that the provisions of fertilizer affected some parameters like the number of tillers, the number of productive tillers, plant height, panicle length, dry seed weight per clump, and 1,000 dry seed weight, but it has the same effect on dry seed weight per panicle and dry kernels weight per m2. The provisions of chicken manure gave the highest outcome to the production of wheat on the number of tillers, the number of productive tillers, panicle length, and 1,000 dry seed weight. NPK gives the highest outcome on plant height and dry seed weight per clump. The treatment of the number of seeds per hill gave the same effect on all observed parameters. [ABSTRACT FROM AUTHOR]

Indonesia is a country, which is prone to geological and hydrometeorological hazards, including volcanic eruptions, earthquakes, tsunamis, floods, and droughts. Systematic initial responses based on efforts for pre-disaster prevention and its corresponding countermeasures need to be prepared for the improvement of the capacity of local communities in managing disaster risks and associated recoveries. Education is, then, considered a way of improving basic knowledge necessary for disaster preparedness and promoting a recovery strategy. Learning about earth-related Disaster Risks Reduction (DRR) fits with Science, Technology, Engineering and Mathematics (STEM) education since a disaster could be best examined across multi-disciplines. While the implementation of a STEM-DRR approach in a classroom setting remains challenging, the current study examined a pattern to follow in STEM-DRR as a potential strategy for increasing awareness of disaster risks at schools. The method used in this study is an exploration with a semi-systematic literature review to reduce a possible bias when facing various terms and procedures in the early development of this approach. The results imply a better look for a future direction of integrated research combining disaster education and STEM. This study could lead to an effective strategy for DRR in school environments with two critical aspects as follows: (1) Strategy for STEM-DRR education depends on both the type and location of a disaster, and (2) A follow-up study to handle the shortcomings found from this study needs to be performed with a broader range of research area coverages, including multidisciplinary approaches. [ABSTRACT FROM AUTHOR]

Stainless steel is an important component in the industrialized world with rising growth in world consumption. It has strong, durable, and economically valuable materials. One of the stainless-steel applications is for nuclear power plant facilities. In Indonesian nuclear industry, stainless steel is not only used for component in purpose reactor but also radiometallurgical facility. The component should be improved for its lifetime to minimize failure. One of the methods that can be used is surface hardening through nitrocarburizing. Where in this method would form compound layer which are ε-Fe2-3 (N, C) 1-z and γ-Fe4N1-x. This study used some different variables, which used different gas ratio dan temperature. The gas diffused with ratio 10% C2H2, 50% argon, and 40% nitrogen. The results show that there is an increase in hardness value, by addition of argon gas up to 50% in the nitrocarburizing process, making the sample harder, the hardness increase was obtained based on the temperature difference used, which increase 1.8-2 times from the initial hardness value. When compared with previous studies, the maximum addition of argon is in the range of 10-30% because it provides a more optimal increase in hardness. [ABSTRACT FROM AUTHOR]