Compressive strength is one of the mechanical properties of rock behavior. This study focuses on the Balikpapan and Kampungbaru Formations located in the Kutai Kartanegara area, East Kalimantan. The Schmidt Hammer testing method was applied due to the lack of previous studies utilizing this tool to evaluate rock hardness in correlation with compressive strength. The research site is situated in the Kutai Kartanegara area, specifically in the districts of Muara Badak, Muara Jawa, and Sanga-Sanga. Field observations revealed the presence of claystone slopes at predetermined locations. Based on the test results, the uniaxial compressive strength (UCS) values for the Balikpapan Formation range from 3.453 MPa to 5.454 MPa, while the Kampungbaru Formation ranges from 3.317 MPa to 8.571 MPa. The Schmidt Hammer rebound number (RN) values for the Balikpapan Formation range from 17 to 19.6, and for the Kampungbaru Formation from 15 to 23.7. A negative correlation was found between the rebound number and UCS, where higher RN values tend to correspond with lower UCS values. This is supported by the linear regression analysis showing a negative coefficient (-0.450).
 

To preserve the environment and culture, the people of Tawun Village in Ngawi Regency routinely carry out the Keduk Beji tradition once a year. This tradition is an annual ritual to clean Sendang Tawun, which aims to maintain ecological balance and prevent the emergence of disasters or plagues. The routine of the Tawun community in carrying out this tradition is based on the oral tradition of “the legend of Sendang Tawun” regarding the origin of Tawun Village. The existence of a tradition that is closely related to the environment has a significant impact on the ecological balance in Tawun Village. This study aims to (1) describe the correlation between Keduk Beji tradition and the legend of Sendang Tawun, (2) describe the procession of the Keduk Beji tradition, and (3) describe the implementation of deep ecology environmental ethics in the Keduk Beji tradition. This research is qualitative research with the object of study being the Keduk Beji oral tradition carried out in Tawun Village, Ngawi Regency. The method used in this study is ethnography, which provides a comprehensive understanding of the impact of implementing the Keduk Beji tradition. Data collection techniques are done through interviews, observations, and documentation studies. The study results show that the Tawun community applies environmental ethics (principles of deep ecology), which are guided by the values ??inherited from their ancestors. This study distinguishes between empirical reality in the form of cultural practices of the community in the Keduk Beji tradition and ideal values contained in the principles of deep ecology as a reference in environmental conservation.

Disposal area is an area at an open pit mine that is used as a place to store or dispose of worthless materials. Disposal must also follow the specified safety factor standards, if the disposal design is not safe after being analyzed by a geotechnical engineer, the design must be redesigned to achieve the desired safety factor value. One way to increase the fk value is to make a Counterweight plan in making disposal. Where Counterweight is a fill material that is made with special treatment so that the soil bearing capacity increases which functions to withstand the load on it. Landslides on disposal slopes are one of the serious problems faced in mining activities, especially in areas with vulnerable geological and topographic conditions. PT Jembayan Muarabara, which operates in Marangkayu District, Kutai Kartanegara Regency, East Kalimantan Province, is no exception to this challenge. The A–A’ cross section shows a safety factor value of 1.118 in saturated conditions, which indicates that the slope is at a stable limit and needs to be improved through engineering such as adding counterweights. The B–B’ cross-section has a safety factor value of 2.332, which is included in the safe category and has met the provisions of the ESDM Ministerial Decree No. 1827 K/30/MEM/2018. The C-C’ cross-section has a safety factor value of 1.511, which is included in the safe category and has met the provisions of the ESDM Ministerial Decree No. 1827 K/30/MEM/2018.

The mining system applied by PT Bukit Baiduri Energi is an open pit mining system utilizing the open-pit method. The application of the open-pit method creates a depression that has a high potential to become a catchment area for both surface runoff and groundwater. In the mining pit of PT Bukit Baiduri Energi, there is a sump located at an elevation of -86 meters above sea level (mdpl). The planned mining boundary is at an elevation of -110 mdpl. Therefore, this research aims to determine the area of the catchment, runoff discharge values, sump capacity, and pump capacity, so that the volume of incoming water can be known, allowing for the control of the sump to prevent overflow that could disrupt mining activities.. Based on the data obtained and the calculations performed, the catchment area was found to be 103.42 ha. In the calculation of runoff discharge using the rational method, the total runoff discharge entering sump A9 was found to be 4,211.66 m3/day. The capacity of the sump was measured at 125,187.62 m3. In the pump capacity calculation, the pump capacity based on the pumping discharge was found to be 2,926.80 m3/day.

Students' understanding of the concept of motion of objects on inclined planes still shows obstacles, especially when applied in real practice. This study aims to see the extent to which students understand the concept through simple experiments and questionnaires. The main focus of the study was on the results of the practicum, where the block slid faster on a smooth plane (an average of 1.25 seconds) than on a rough plane (an average of 1.61 seconds). This time difference reflects the effect of friction on the motion of objects, but some students were unable to explain the difference correctly. This indicates that there are still misconceptions in understanding the concepts of force and motion. Meanwhile, the results of the questionnaire only reinforced that most students felt the need for direct practice to understand this material. Thus, a practice-based learning approach is very important to strengthen students' conceptual understanding in Basic Physics courses.
 

West Java is a province rich in history, culture, and traditions that form an essential part of Indonesia's national identity. Culture-based education plays a strategic role in shaping the character and cultural appreciation of younger generations toward the nation's heritage. This study employs a qualitative approach by introducing elements of West Javanese culture to students at SDN Sepang, Serang City, through visual learning media. The visuals depict cultural elements such as Jaipong dance, Wayang Golek puppetry, Angklung musical instruments, traditional clothing, and regional cuisine. The findings indicate that visual media effectively enhances students' interest and understanding of local culture while fostering a sense of pride and love for cultural heritage. The pedagogical approach, inspired by the Montessori method, offers students the freedom to explore, thereby promoting creativity and independence in learning about culture. This cultural learning not only preserves traditional values but also serves as a means of social transformation in addressing the challenges of globalization. The study emphasizes the importance of integrating local culture into the formal education curriculum, the need for teacher training, and community involvement to support sustainable cultural education. Therefore, culture-based education can serve as a strong foundation for cultivating knowledgeable, culturally-rooted, and character-driven future generations, contributing to sustainable national development.

This study aimed to develop a competency-based performance evaluation model for mathematics teachers at the junior secondary level. Recognizing the crucial role of teacher quality in student achievement, the study focused on measurable aspects of performance, including content mastery, instructional management, and professional commitment. A quantitative approach was employed using a research and development (R&D) framework, supported by a quasi-experimental design with pretest-posttest control groups. Data were collected via structured questionnaires, classroom observations, interviews, and expert validations through focus group discussions. Statistical analyses included descriptive statistics, ANOVA, t-tests, and confirmatory factor analysis using SPSS and LISREL. The results indicated that the developed model effectively differentiated teacher performance across various school categories, with 45% categorized as good, 53% adequate, and 2% poor. Student achievement was positively correlated, with 82% achieving the minimum competency threshold. The factor analysis confirmed a valid measurement model: F1 = 0.505ZX1 + 0.475ZX2 + 0.308ZX3, explaining 57.92% of the variance in teacher performance. The findings suggest that teacher evaluation must integrate multidimensional competencies and contextual factors to be accurate and actionable. This study contributes a validated, data-driven evaluation framework aligned with national standards and global educational expectations, offering practical implications for policy, supervision, and teacher development.

This study discusses the concept and online buying and selling transactions that comply with sharia principles. This study aims to analyze the validity of online buying and selling transactions based on the perspective of fiqh muamalah. This study uses qualitative descriptive and literature research methods by examining materials related to the Analysis of Online Shopping Transactions in the Perspective of Fiqh Muamalah and Sharia compliance. The results of the study indicate that online shopping transactions can be considered valid according to sharia if they meet four main requirements, namely the existence of the transacting parties, the existence of ijab and qabul, clarity of the object of the transaction, and a halal purpose. In addition, the principles of transparency, honesty, and freedom from usury and gharar are important requirements in maintaining the justice and validity of online buying and selling according to Islamic law.Keywords : Online buying and selling, Islamic jurisprudence, Sharia compliance, Transaction validity, Offer and acceptance

Students in the Information Systems Program at UIN Sumatera Utara tend to have irregular eating patterns with high consumption of fast food. This habit contributes to various health problems such as digestive disorders and decreased concentration. This study was conducted to investigate the eating patterns of students in the Information Systems Program at UIN Sumatera Utara and their relationship with their health conditions. Through a quantitative survey of 50 respondents, the results showed that most students eat less than three times a day, with the highest frequency being twice a day (48%). Additionally, the majority of students consume fast food 1–2 times a week (60%). Analysis using the Chi-Square test revealed a significant association between the frequency of fast food consumption and students' health conditions (p < 0.05). Many students experienced health issues such as stomach problems and fatigue related to their unhealthy eating patterns. These findings emphasize the need for nutrition education and the implementation of practical healthy eating patterns to support students' health and academic performance.

The implementation of coal mining activities with an open pit system at the end of its activities will leave behind the remains of former mining holes. Control of acid mine water is something that needs to be done during mining activities until the end of the mining process because acid mine water can cause a decrease in the quality of surface water and groundwater and have an impact on the survival of humans and biota that live on land and water. The initial characteristics of water using the floating treatment method of wetland, the pH, TSS, Fe, and Mn values ??of ex-mining lake water do not meet the quality standards of the Government Regulation of the Republic of Indonesia Number 22 of 2021. The ability of water hyacinth plants to increase pH for 25 days is quite good with an initial pH value of 4.13 to 7.34. For 25 days, the TSS parameter of water hyacinth plants is also good at reducing TSS levels with an initial value of 6 mg/L to 3 mg/L, the Fe parameter of water hyacinth plants is also good at reducing iron levels with an initial value of 1.06 mg/L to 0.34 mg/L, while the Mn parameter of water hyacinth plants is quite good at reducing manganese levels with an initial value of 1.13 mg/L to 0.32 mg/L.