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LITHOLOGICAL IDENTIFICATION USING RESISTIVITY GEOELECTRIC METHOD IN LANDSLIDE AREA IN BENGLE VILLAGE
No full textDesa Dlepih, tepatnya di Dusun Bengle, merupakan wilayah yang mengalami bencana tanah longsor pada tanggal 28 November 2017. Bencana tanah longsor ini terjadi di permukiman penduduk dan mengakibatkan 2 orang meninggal dunia sehingga diperlukan tindakan mitigasi. Salah satu langkah awal mitigasi adalah mengidentifikasi litologi di area tanah longsor. Penelitian ini bertujuan untuk mengetahui litologi di area tanah longsor dengan menggunakan metode geolistrik resistivitas dipole-dipole. Pengambilan data dilakukan dengan menggunakan seperangkat instrumen Naniura Resistivity Meter pada empat lintasan pengukuran. Lintasan pengukuran berada pada Formasi Semilir yang terdiri dari batuan sedimen. Hasil penelitian menunjukkan bahwa daerah longsor tersebut terdiri dari lapisan tanah dengan nilai resistivitas 2,32 Ωm – 6,69 Ωm dan ketebalan 1,26 m – 11,39 m, lapisan batulempung dengan nilai resistivitas 6,69 Ωm – 160 Ωm dan ketebalan 11 m – 40,5 m, dan lapisan batuan andesit dengan nilai resistivitas lebih dari 160 Ωm dan ketebalan 5,25 m – 37,71 m
Experimental Study on The Infiltration and Compressive Strength of Porous Paving Blocks Composed of Fly Ash and Zeolite Mixture
Full text linkMaximizing the absorption of water into the soil to reduce puddles in developing areas can be done by using porous paving blocks as cover for soil reports with water escape capabilities. Paving block porous materials need to be considered qualified quality according to their use. Fly ash as one of the coal-burning wastes can be used as a substitution material for cement. Zeolite instead of gravel is a source of considerable mining material, structured hydrate aluminum silicate with a high specific surface area and has a great potential for use as an absorbent material that can pass through water. This study investigates the use of fly ash as substitute of cement and zeolite as aggregates in porous paving block. The research aims to identify optimal composition of fly ash and zeolite for achieving desirable compressive strength and infiltration. Porous paving block were manufacture using ratio 1 (segment): 4 (grains) of binder to aggregate. Fly ash waste used in a mixture of porous paving block materials varies by 10%, 20%, 30% and 40% using rough aggregates of zeolite. Compressive strength tests are performed at 7 days, 14 days and 28 days and for infiltration tests at 28 days. Research showed compressive strength values of 31.40 MPa, 36.75 MPa, 37.50 MPa, 32.42 MPa, and 32.67 MPa, respectively, can be used as a parakeet cover layer. The infiltration coefficients are 0.0611 cm/s, 0.4376 cm/s, 0.1218 cm/s, 0.0621 cm/s and 0.1012 cm/s, respectively, which are capable of passing water from the surface to the ground. This study highlights the potential of utilizing waste material fly ash and zeolite in quality of porous paving blocks, contributing to sustainable construction and stormwater management in urban areas
Microplastic Contamination in Yogyakarta's Rivers: Spatial Analysis and Factor Assessment to Identify Key Pollutants
Full text linkRiver water quality monitoring aims to determine the state of river water quality and to ensure its safety for human health and the sustainability of its use. Some important parameters that are often used to measure river water quality include chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), pH, Temperature, and microplastic content. This study uses multiple linear regression to determine which factors contribute significantly to river water quality. Samples were collected from the Winongo, Gadjah Wong, Bulus, Oyo, Belik, Tambakbayan, Opak, and Kuning rivers in Daerah Istimewa Yogyakarta (DIY) and distributed in 20 points. The results of the correlation matrix show the relationships between the variables in the data. The DO variable has the most substantial relationship with microplastics, suggesting that water quality, measured by oxygen levels, may be related to microplastic pollution. The relationship between pH and Temperature is also moderate. However, other relationships tend to be weak, suggesting that other factors may be more influential in determining these variables' relationships. The multiple linear regression model shows that an increase in pH, a decrease in Temperature, an increase in DO, and a decrease in TSS will increase the amount of microplastics. Furthermore, through spatial analysis and geographically Weighted Regression (GWR) modelling, DO significantly affects 12 observation points and does not affect eight. The spatial approach shows that the causes of river water pollution are different in each location. Therefore, each site's treatment is also different according to its characteristics
Preliminary Design of a Catamaran Ship for Water Tourism in Lake Sunter
Full text linkLake Sunter, an man-made lake built since the 1970s and covering approximately 33 hectares, is commonly referred to as Lake Podomoro. Positioned as an urban recreational space, its scenic vistas offer potential for diverse water-based activities. In order to increase tourist engagement with the lake, it is imperative to diversify the available attractions. Among these attractions, tourist boats emerge as a viable option to capture public interest. Accordingly, this study attempts to design a catamaran tour boat equipped with motorcycle propulsion, tailored for operation on Lake Sunter. In the first stage, the primary dimensions of the catamaran vessel are determined using the linear regression method, resulting in dimensions of L = 3.2m, H = 1.15m and T = 0.4m, with a passenger capacity of 3 persons. The ship's stability is then assessed in accordance with the criteria of the IMO A.749 (18) Code On Intact Stability, Chapter 3, which applies to all ship designs. This assessment includes Load Case I and Load Case II conditions to determine the stability of the ship under different scenarios
Optimasi Pola Tanam pada Daerah Irigasi Baru Wilayah Cluring Kabupaten Banyuwangi dengan Menggunakan Program Linear
Full text linkDaerah Irigasi Baru mengalami permasalahan pola tanam yang berdampak pada ketersediaan pangan. Optimasi pola tanam telah dilakukan oleh peneliti terdahulu yakni pada tahun 2016 dan diperoleh pola tanam padi/palawija – padi/tebu – padi/palawija/tebu dengan intensitas tanam 300% dan keuntungan hasil pertanian yang diperoleh selama setahun adalah Rp. 224,826,400.00. Optimasi ulang perlu dilakukan untuk mendapatkan pola tanam paling optimal pada saat ini. Optimasi ulang dilakukan menggunakan data curah hujan dan klimatologi dari tahun 2012-2021 dengan metode program linear menggunakan software POM-QM 3. Berdasarkan optimasi luas lahan tanam, didapatkan intensitas tanam dalam setahun sebesar 300% dan keuntungan hasil pertanian dalam setahun sebesar Rp. 2,145,200,000,000.00 pada alternatif pola tanam 1 skenario B dengan pola tanam padi/palawija/jeruk - padi/palawija/jeruk - padi/palawija/jeruk. Berdasarkan optimasi keuntungan hasil pertanian, didapatkan intensitas tanam dalam setahun sebesar 300% dan keuntungan hasil pertanian dalam setahun sebesar Rp. 2,443,395,000,000.00 pada alternatif pola tanam 1 skenario A dengan pola tanam jeruk – jeruk - jeruk
Manajemen Dan Rekayasa Lalu Lintas Simpang Menggunakan Simulasi PTV Vissim 9.0 (Studi Kasus: Dua Simpang Jln. Cak Doko Kecamatan Oebobo Kota Kupang)
Full text linkTwo adjacent intersections on Cak Doko Street, Oebobo District, Kupang City cause traffic jams, so evaluation and simulation of Traffic Management and Engineering recommendations are needed. The analytical method used is intersection evaluation using the PTV Vissim 9.0 simulation programs and PKJI 2023. The results of the PTV Vissim 9.0 evaluation will be calibrated and validated and then used as a basis for recommended traffic management and engineering simulations. The intersection evaluation results for intersection delay values at intersections 1 and 2 are 15,392 sec/veh and 13,738 sec/veh (PKJI 2023) and 41,755 sec/veh and 28,379 sec/veh (PTV Vissim), while the respective LOS values are LOS E and LOS D. The most effective traffic menagement is recommendation 2, namely the installation of a median with a U-turn ban at both ends of the median, with the performance results for intersections 1 and 2 being LOS B with intersection delays of 11,497 sec/veh and 10,565 sec/veh, respectively.Dua simpang tiga yang berdekatan pada Jl. Cak Doko, Kecamatan Oebobo, Kota Kupang menyebabkan terjadinya kemacetan sehingga perlu adanya evaluasi serta simulasi rekomendasi Manajemen Dan Rekayasa Lalu Lintas (MRLL). Metode analisis yang digunakan adalah evaluasi simpang menggunakan simulasi program PTV Vissim 9.0 dan PKJI 2023. Hasil evaluasi PTV Vissim 9.0 akan dikalibrasi dan divalidasi untuk kemudian digunakan sebagai dasar simulasi manajemen dan rekayasa lalu lintas yang akan direkomendasikan. Hasil evaluasi simpang untuk nilai tundaan simpang pada simpang 1 dan 2 masing-masing sebesar 15,392 det/kend dan 13,738 det/kend (PKI 2023) serta 41,755 det/kend dan 28,379 det/kend (PTV Vissim), sedangkan nilai LOS masing-masing adalah LOS E dan LOS D. Rekomenasi MRLL yang paling efektif dilakukan adalah rekomendasi 2 yakni pemasangan median dengan larangan putar balik pada kedua ujung median, dengan hasil kinerja simpang 1 dan 2 adalah LOS B dengan tundaan simpang masing-masing sebesar 11,497 det/kend dan 10,565 det/kend.
Design of Toll Road Embankment With Secondary Compression Mitigation After Pvd Installation and Solutions For The Probolinggo – Banyuwangi Toll Road Construction Project Package 2 Sta 16+300 – Sta 16+700
Full text linkIn the Probolinggo-Banyuwangi Toll Road construction project package 2, there are several areas where the subgrade consists of soft soil, one of which is at STA 16+300 – STA 16+700. In this section, soft soil with a depth of up to 12 meters is found. The primary issue in constructing on soft soil is settlement. Settlement occurs due to the high compressibility of clay, where consolidation takes an extended period. This condition may pose problems during both the construction and operational phases of the toll road due to ongoing settlement.Consolidation consists of primary consolidation and secondary compression. Primary consolidation occurs first, followed by secondary compression. The method used in this study to accelerate primary consolidation and secondary compression involves prefabricated vertical drains (PVD) combined with preloading. The study was conducted at STA 16+300 – STA 16+700, where compressible soil with a depth of 12 meters is present, but the embankment height varies. For this study, embankment heights of 4m, 6m, and 8m were analyzed. Once the magnitude of primary consolidation and secondary compression from year 2 to year 15 was determined, the results were evaluated based on the Binamarga standards. Specifically, the settlement requirements are as follows: during the 2nd and 3rd years, settlement must be less than 2 cm; during the 2nd and 12th years, it must be less than 10 cm with a construction period of 2 years and maintenance of 1 year; and during the 5th and 6th years, it must be less than 2 cm; while during the 5th and 15th years, it must be less than 10 cm with a construction period of 3 years and maintenance of 2 years. From these results, the required embankment heights for which preloading is necessary were identified.Slope stability analysis for the embankment was also conducted to determine whether the stability meets the required standards. If the stability requirements were not met, reinforcement using geotextile material was applied. Therefore, for each embankment variation, the necessary amount of geotextile was determined.The results of this study show that the settlement requirements of Binamarga were met during the 2nd and 3rd years, the 5th and 6th years, and the 5th and 15th years, but not during the 2nd and 12th years, indicating the need for preloading. Regarding embankment stability, the factor of safety for all embankment variations was found to be below the required standard, necessitating the use of geotextile reinforcement. Based on these results, this study serves as input for selecting the appropriate method and ensuring a faster implementation period for the toll road construction
Functionalization of Carbon Nanotubes as Support Material of Pt/CNTs Catalyst for Proton-Exchange Membrane Fuel Cell
Full text linkThe Proton Exchange Membrane Fuel Cell (PEMFC) is a type of fuel cell that converts hydrogen fuel into electrical energy. In PEMFC, platinum (Pt) supported by carbon black (CB) is frequently used as a catalyst. The catalyst has several constraints cause it to agglomerate and corrode during fuel cell operations. Carbon Nanotubes (CNTs) are a contender as a catalyst-supporting material because they offer superior properties such as hydrophobicity, conductivity, and surface area. This study used pH modifications in the synthesis process, morphology, and electrochemical performance of the Pt/CNTs catalyst to evaluate the reduced size of Pt particles and increased CNTs surface area. During the catalyst synthesis procedure, colloidal solutions with pH variations of 11 and 13 were utilized. TEM analysis showed that at pH 13, the produced Pt nanoparticles had the least average particle size of 4.2 nm, followed by 5.1 and 7.9 for pH 9 and 11, respectively. The best electrochemical performance was achieved in pH 13 samples with the largest active surface area of 40.33 m2/g, an onset potential of 0.798 V involving 4.01 electrons for the oxygen reduction reaction, and the lowest risk of deterioration
Compressive Strength Performance of High-Volume Fly Ash Concrete with CaCO3 Addition
Full text link This study investigates the compressive strength performance of High-Volume Fly Ash (HVFA) concrete with added CaCO₃ as a sustainable alternative to Ordinary Portland Cement (OPC) for infrastructure applications. The experimental research replaces a significant portion of cement with fly ash—a byproduct of coal combustion—aiming to reduce greenhouse gas emissions associated with concrete production. Two HVFA concrete mixtures were developed, substituting 37% and 47% of cement content with fly ash and adding 3% CaCO₃ to enhance mechanical properties. Material characterization, including XRF and XRD analysis, confirmed the suitability of fly ash for concrete production based on ASTM C618-19 standards. Aggregate gradation, moisture content, and specific gravity tests were conducted to optimize the mix design. Compressive strength tests were performed at 7, 14, and 28 days, showing that HVFA concrete with 37% fly ash substitution achieved higher strength values, reaching 25.92 MPa at 28 days, compared to the 47% mix, which reached 24.68 MPa. Slump tests indicated sufficient workability, with a measured slump of 10 cm for FA37C3 and 12 for FA47C3. These findings suggest that HVFA concrete with moderate fly ash substitution, complemented by CaCO₃ addition, can achieve compressive strength and workability comparable to OPC, supporting the development of environmentally friendly concrete solutions.
Analysis of Passenger Ability and Willingness to Pay for the Surabaya-Yogyakarta Train Route
Full text linkThe Directorate General of Railways of the Ministry of Transportation has been constructing double-track railway lines along the southern route of Java since 2015, covering a distance of 694 km This project aims to connect three major agglomeration cities, namely Jabodetabek, Joglosemar (Jogja - Solo - Semarang), and Gerbangkertosusila (Gresik - Bangkalan - Mojokerto - Surabaya - Sidoarjo - Lamongan). PT Kereta Api Indonesia accelerated travel times for several trains using the south of Java double-track railway starting September 24, 2021, as part of service improvements. In line with the construction of the double-track railway and service improvements by the Directorate General of Railways of the Ministry of Transportation and PT Kereta Api Indonesia, ticket/fare rates need to be reviewed, especially if there is an increase in ticket prices for the economy and executive classes, which include the Wijayakusuma, Sancaka, and Mutiara Selatan trains. This research aims to determine passenger characteristics, Ability to Pay (ATP), and Willingness to Pay (WTP) for the services used and to provide alternative scenarios in the event of fare increases to improve service quality. The methods used to address these issues include collecting primary data through interviews and questionnaires, analyzing respondent characteristics, and analyzing willingness and availability to pay using the Stated Preference approach. Subsequently, the Household Budget method and service user perceptions will be employed to obtain ATP and WTP values. The results of this study for the economy class show an Ability to Pay (ATP) value of IDR 307.249 and a Willingness to Pay (WTP) value of IDR 250.593. For the executive class, the ATP value is IDR 396.943, and the WTP value is IDR 277.462