KURVATEK

THE IMPACT OF TOTAL MOISTURE AND ASH ON CALORIFIC VALUE: COAL RESEARCH IN BERAU SUB-BASIN, EAST KALIMANTAN

Wahyu Sugiarto — 2025-04-29

Coal quality is one of the key factors in determining the effectiveness of processing and utilization. Coal quality assessment involves analyzing physical and chemical aspects to determine its characteristics. Coal quality is also influenced by geological conditions at the mining site, which affect the quality and amount of carbon in the coal. To ensure consistency, it is necessary to implement coal quality control based on physical and chemical parameters from the mining process in the pit to storage in the stockpile. Analysis of the effect of total moisture and ash on the calorific value of coal is the purpose of this study. The method used is a ROM (Run of Mine) coal sample located at the stockpile location. The relationship between Total Moisture and the calorific value of coal shows a negative linear correlation where the influence value for a 1% increase in Total Moisture is -71.343 kcal/kg and so is between Ash and the calorific value of coal 1% increase in Ash is -82.588 kcal/kg, which shows a negative linear correlation. Total Moisture increases by 1%, reducing the calorific value of coal by 71 kcal/kg, and increasing Ash content by 1% reduces the calorific value of coal by 83 kcal/kg.

THE INFLUENCE OF STAKEHOLDERS MANAGEMENT ON TRUST IN CONSTRUCTION PROJECTS

Buddewi Sukindrawati — 2025-04-29

Stakeholders are groups or individuals who can influence or be influenced by the achievement of organizational goals. Stakeholder management is identified as the process by which the project team manages stakeholder needs and ensures their goals are achieved. The purpose of this study is to examine factors that influence stakeholder management on trust in construction projects that have an impact on project success.

The research method used is a quantitative method with a total of 124 respondents in contracting companies in the Yogyakarta Special Region. The analytical method used is multiple linear regression analysis with the help of a computer program data processing tool SPSS 25.0..

The results of the research on the factors that influence stakeholder management on trust in construction projects are prescriptive stakeholders management (X1), intuitive trust (X2), competence trust (X4), honesty (X5), integrity trust (X3), and communication (X6). The result of the analysis states that the most dominant variable which significantly influences the prescriptive stakeholder management (X1), hence it is important for stakeholders mapping, identification, classification, and monitoring from the start of the project

RELATIONSHIP OF SUSTAINABLE TRANSPORTATION INFRASTRUCTURE ELEMENTS IN THE RICE COMMODITY SUPPLY CHAIN IN KULON PROGO

Ridayati Ridayati — 2025-04-29

Adequate and sustainable infrastructure serves as a strong foundation for ensuring the efficiency, effectiveness, and sustainability of the rice supply chain. The rice supply chain is a complex system involving various actors and processes, from farmers to consumers. In-depth studies of this supply chain are crucial given the importance of rice as a staple food. This article aims to provide an overview of the interconnections between infrastructure elements in the rice supply chain. Previous studies on the rice supply chain have been limited to a single perspective, such as from the perspective of farmers as producers or rice as a product. This article attempts to explore new insights by measuring the interconnectedness of key elements in the rice supply chain. The method used is Network Enabling Transport Service (NETS), which is commonly used in the transportation field. Variables studied include infrastructure, traffic, regulations, communication, support services, and skills. The research results show that the weakest link in the rice supply chain network lies in the regulatory variable. Weak regulations can hinder efficiency, fairness, and sustainability in the supply chain. These findings underscore the importance of improving policies and regulations to support better integration of the rice supply chain. Regulations are particularly related to the development of infrastructure for the efficiency and resilience of the rice supply chain in the face of climate change challenges and demand fluctuations. Adequate infrastructure, such as roads, irrigation, and storage, is crucial to ensure the stable availability of quality rice

ANALISIS HIDROLOGI DENGAN MENGGUNAKAN METODE RASIONAL DAN NAKAYASU UNTUK EVALUASI PERIMETER DITCH

M Arif Abdillah — 2025-04-29

RANCANGAN SISTEM PENYALIRAN TAMBANG PADA TAMBANG BIJIH NIKEL PIT HILL ANYER

Zulfikar Aulia Alisaputra Alisaputra — 2025-04-29

Penelitian ini bertujuan merancang sistem penyaliran tambang untuk mengatasi masalah genangan pada lantai pit akibat curah hujan tinggi. Berdasarkan analisis hidrologi menggunakan data curah hujan 15 tahun (2009-2023), metode distribusi Gumbel dipilih dengan curah hujan rencana 75 mm, intensitas curah hujan 16,38 mm/jam, dan periode ulang hujan 2 tahun. Terdapat empat daerah tangkapan hujan (DTH) di area pit, dan desain sistem penyaliran tambang meliputi saluran terbuka, gorong-gorong, dan kolam pengendapan. Dimensi saluran dan gorong-gorong dirancang berdasarkan debit air limpasan masing-masing DTH. Kolam pengendapan terdiri dari tiga kompartemen dengan waktu pemeliharaan 100-1292 hari. Desain ini diharapkan efektif dalam mengelola air limpasan untuk mendukung operasional tambang.

PERENCANAAN PUSAT KESENIAN TRADISONAL DENGAN PENDEKATAN ARSITEKTUR NEO VERNAKULAR DI KABUPATEN BANYUMAS

Elin Dea Putri — 2025-04-29

Indonesia merupakan negara dengan populasi terbesar di Asia Tenggara, yang memiliki keberagaman sumber daya manusia dan budaya. Keragaman bahasa, budaya, dan etnis tersebut telah melahirkan berbagai warisan budaya baik benda maupun non benda yang menjadikan ciri khas serta identitas bangsa Indonesia. Kabupaten Banyumas memiliki beragam kesenian tradisional yang potensial. Terjadinya perubahan secara terus menerus di bidang sosial budaya, yang dipengaruhi oleh pembaharuan di bidang ilmu pengetahuan, teknologi dan terbukanya informasi serta kemudahan dalam mengakses berbagai sumber, bisa menjadi ancaman dan tantangan tersendiri dalam mempertahankan budaya Banyumas tersebut. Untuk itu perlu adanya wadah, sebagai sarana untuk melestarikan dan mengembangkan kesenian tardisional dalam bentuk pusat kesenian tradisional Banyumas. Penerapan konsep Arsitektur neo vernacular menjadi pilihan dalam perancangan, bertujuan untuk memadukan unsur-unsur tradisional lokal dengan langgam modern. Hal ini mencerminkan bahwa budaya local/tradisional setempat mampu menyelesaikan masalah sosial budaya melalui pendekatan arsitektural.

SISTEM DETEKSI KEBAKARAN “SiDinKar” SECARA REAL TIME BERBASIS INTERNET OF THINGS

Chrisna Putra Buana — 2025-04-29

The Fire Detection System emerged because of the many fires in the room. Aims for early detection of room / room conditions from the possibility of fires based Internet of Things. By utilizing internet connectivity in controlling hardware : smoke sensors, fire sensors and buzzer. Displays smoke and gas values and detects the presence or absence of fire in a room and provides notifications when the displayed value exceeds certain limits by using the mobile application on the Android smartphone and buzzer at NodeMCU. This tool uses several devices to connect the process between the response from the sensor and the application. Smoke sensors and fire sensors as data retrieval from objects. NodeMCU is used as a microcontroller. Firebase is used to store temporary data and to link applications with tools. The mobile application, namely SiDinkar, is used to monitor the conditions of gas, smoke and fire in the room. Notification in mobile application is used and buzzer in NodeMCU for alerts under certain conditions. The results of the tests that have been carried out are that the tool is able to display data in the form of smoke and fire taken from Firebase by the Android Application “SiDinKar”. The data displayed on the mobile application is realtime. To access the application in order to monitor realtime requires an internet connection.

ANALYSIS OF NATURAL COMPACTION IN MRT TUNNEL CP201, CENTRAL JAKARTA

Muhammad Adi Naufal — 2025-04-29

This study analyzes the land subsidence caused by natural consolidation in the Thamrin Area, Central Jakarta, along the MRT CP201 tunnel route. Jakarta’s soft soils, particularly clay layers, contribute to land subsidence, with 0.2 to 3.6 meters and rate of subsidence is 1,24 cm/years. Using both analytical (one-dimensional consolidation) and numerical (finite element) methods, subsidence predictions were made based on geotechnical data from three boreholes which is TS-01,TS-02 and TS-03. Results show positive correlation between the two methods, with numerical approach yielding slightly smaller values due to its consideration of both vertical and horizontal deformations. This analysis highlights unavoidable nature of subsidence due to natural consolidation and emphasizes the need for mitigation and adaptation measures, such as spatial planning and monitoring systems, to minimize impacts on infrastructure.

OPTIMALISASI PERENCANAAN PRODUKSI DAN ANALISA POTENSI USAHA BETON GEOPOLIMER BERBASIS FLY ASH DAN BOTTOM ASH

Muhammad Faiz Shafiyurrahman — 2025-04-29

Dry geopolymer-based concrete from fly ash and bottom ash has been widely developed with the aim of advancing infrastructure to build a sustainable industry from the utilization of such waste. Planning for the construction of a concrete derivative product production business needs to be carried out to optimize the utilization of the budget, warehouse stock, and profit. The derivative products used in this study are paving blocks, adobes, and kanstin with compressive strength standards of 25 MPa, 10 MPa and 30 MPa respectively. Based on the compressive strength standard, the FA:BA ratio of each product is successively 3:1; 1:1; and 1:0 [1]. Therefore, the purpose of this study is to maximize profits by optimization production and raw materials based on calculations simplex linear programming method and conducting business feasibility studies using the SWOT method. Based on the calculation results, the business was focused on paving block products with a total production of 431 pcs/h. with total raw material needs of fly ash 1,199 tons / hour and bottom ash 0,399 tons / hour with a total profit of IDR 172,413. Based on the feasibility test of dry geopolymer concrete products using the SWOT method, it can be said to have great opportunities with its advantages.

ANALISIS MANIFESTASI PANAS BUMI MELALUI FAULT FRACTURE DENSITY (FFD) DI WILAYAH KAMOJANG, KECAMATAN SAMARANG, KABUPATEN GARUT

Muhammad Faza Syaddad Ar-rafi — 2025-04-29

Located on the Pacific Ring of Fire, Indonesia has great potential in significant geothermal energy. Kamojang, located in Samarang District, is one of the areas that show this potential. This study aims to assess the existence of geothermal potential in Kamojang through fault density analysis using the Fault Fracture Density (FFD) method. The data used are fault patterns from the National Digital Elevation Model (DEMNas) which are then analyzed to calculate the density of cracks and presented in the form of contour maps. The resulting FFD values range from -0.5 to 9.5 km/km². The results show that the alignment pattern in Kamojang is mostly northwest - southeast, which is closely related to tectonic movements and the formation of active faults in the area. Although the FFD value in this area is relatively low, the presence of active faults still provides a pathway for the movement of geothermal fluids that form geothermal manifestations such as geothermal craters. These results provide important insights to support the management and development of geothermal energy in the Kamojang area.

PENERAPAN METODE ORDINARY KRIGING UNTUK ESTIMASI SUMBERDAYA TIMBAL (Pb) PADA BLOK GOSSAN

Tommy Tommy — 2025-04-29

Pada daerah penelitian merupakan litologi yang kompleks (batuan vulkanik, sedimen, alterasi hidrotermal menyulitkan korelasi lapisan. Sebaran kadar timbal tidak homogen digunakan penerapan ordinary kriging untuk estimasi timbal dengan litologi kompleks dan alterasi hidrotermal. Berdasarkan metode ordinary kriging, sumberdaya timbal (Pb) diklasifikasikan ke dalam tiga kategori, yaitu measured (volume 2.012.325 m³, tonase 15.092.439 ton, kadar Pb 3,7%), indicated (volume 1.555.856,25 m³, tonase 11.668.921 ton, kadar galena 3,9%), dan inferred (volume 7.309,25 m³, tonase 54.819 ton, kadar Pb 4%). Hasil perhitungan menunjukkan nilai RMSE sebesar 0,40, koefisien korelasi (r) 0,67, dan koefisien determinasi (R²) 0,44, yang mengindikasikan akurasi model yang cukup baik dengan hubungan yang kuat antara nilai estimasi dan aktual.

LIMITTING REDUCTION RATIO AS THE SIZE LIMIT FOR MATERIAL REDUCTION OPERATIONS IN A SINGGLE TOGGLE JAW CRUSHER

Erry Sumarjono — 2025-04-29

Reduction Ratio (RR) can be used to estimate the size of product that can be produced by a crusher. The reduction ratio can be calculated in several ways. One calculation that can be done is calculating the Limitting Reduction Ratio (LRR). Limiting Reduction Ratio is a comparison between the largest feed size and the largest product size. This research aims to calculate the Limiting Reduction Ratio in clay stone crushing operations for 30 samples, which was carried out on a laboratory scale, using a single toggle jaw crusher type crusher. Crushed products are separated by hand sieving sizes +4#, 10#, 20#, 40#, 60#,100#, 200#. The research results show that the percentage of crushed products produced is still found in the largest sieve size, namely 4#, with an average amount of 52.33%. The largest feed size ranges from 24 mm to 27 mm and the largest product size ranges from 4 mm to 6 mm. The relationship between total feed weight and total product weight can be expressed in the equation Y = 0.5229 X and R² = 0.9228, while the relationship between the largest feed size and the largest product size is expressed in the equation Y = 0.2044 X and R² = 0.9761. The calculation of the limiting reduction ratio ranges from 4.2 to 6.8, with an average value of 5.02.

Keywords: Crushing, Jaw Crusher, Mineral Processing, Reduction Ratio, Reduksi

DETAIL MORPHOLOGICAL ANALYSIS TO MAPPING SURFACE LITOLOGICAL CHARACTERSTIC UNIT

Febrian Maritimo — 2025-04-29

Regional spatial planning requires accurate data according to the planning scale. One of the problems encountered in the analysis of spatial planning in Indonesia is the unavailability of some basic data that have a level of detail according to planning needs, including geological data. RTRWK requires a map at a scale of 1:50,000, while the availability of a Geological Map at a Scale of 1:50,000 from the Ministry of Energy and Mineral Resources is still very limited. This study aims to produce surface geological distribution data and its characteristics needed in spatial planning with a morphological analysis approach. Detailed morphological analysis is carried out by processing Digital Elevation Model data with a spatial resolution of 8 meters. Detailing of the morphological classification is carried out on the BMB classification. Morphological interpretation is carried out in stages by dividing the land surface from general to detailed, producing classes of high ridged hills, low ridged hills, undulating valleys between hills and plains. Landform interpretation is carried out by adding geological structure data and rock types in the analysis, producing landform classes of high hills elongated fault zones, low hills elongated fault zones, undulating valleys between hills in fault zones, and alluvial plains. Landform units of elongated hills of fault zones can be detailed based on the relief pattern and slope gradient into ridge, steep slope, and gentle slope. Low hills elongated fault zones can be divided into ridge and gentle slope. Meanwhile, the undulating valleys between the hills of the fault zone and the alluvial plains do not show any further variations. The andesite breccia rock unit is the lithology that forms the morphology of elongated ridged hills, the undulating valleys between the hills are formed from andesite breccia colluvium rock units, while the alluvial plains are formed from alluvium rock units. The division of detailed morphology in the hills reflects the differences in the characteristics of the degree of weathering of the rocks and the weathering materials. The andesite breccia rock unit on the ridge experiences strong weathering and produces a lot of in-situ soil material. The andesite breccia bedrock exposed on steep slopes experiences early weathering with thin soil deposits on top and has several andesite boulders deposited in the bends of the slopes. Gentle slopes have surface rock units dominated by colluvium material. This unit consists of andesite breccia boulders scattered on the surface mixed with weathered soil material from ridge and/or steep slopes. The undulating valleys between hills also have characteristics of surface rock units consisting of andesite breccia boulders on the land surface with thick soil resulting from the accumulation of weathered soil from the hills. Alluvial rock units on alluvial plains do not reflect significant variations.

OPTIMIZATION OF HYBRID PHOTOVOLTAIC THERMOELECTRIC GENERATOR SYSTEM FOR IMPROVING SOLAR PANEL EFFICIENCY

Linda Faridah — 2025-04-29

The utilization of solar energy through photovoltaic (PV) technology continues to evolve as a promising renewable energy source. However, the efficiency of solar panels remains limited by heat generated during operation, causing performance degradation as temperature rises. This phenomenon presents a major challenge in optimizing PV technology. This research aims to enhance the efficiency of photovoltaic systems by incorporating Thermoelectric Generator (TEG) modules, resulting in an innovative hybrid Photovoltaic-Thermoelectric Generator (PV-TEG) system. The PV-TEG hybrid system is designed to harness excess heat produced by solar panels, which is then converted into additional electrical energy through TEG modules, utilizing the Seebeck effect. In this experimental study, two heat transfer methods were tested and compared: Micro-Channel Heat Pipe (MCHP) and copper plate. Both methods were evaluated to enhance the temperature gradient across the TEG modules, with the goal of optimizing the hybrid system's performance. The research methodology included design, fabrication, and testing of PV-TEG hybrid system prototypes under various controlled environmental conditions. Measured parameters included operational temperature, output voltage, current, and total power generated. Thermodynamic and electrical analyses were conducted to evaluate energy conversion efficiency and overall system performance. Test results showed that the PV-TEG hybrid system could increase overall efficiency by up to 10% compared to conventional solar panels. The use of copper plates as heat transfer media resulted in higher efficiency compared to MCHP, indicating greater potential for practical implementation. Economic analysis also demonstrated the long-term feasibility of this hybrid system, despite higher initial costs.In conclusion, the developed PV-TEG hybrid system makes a significant contribution to improving the energy efficiency of solar panels.