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Core Learning Model and Mathematical Disposition, Against Mathematics Problem Solving Ability of Elementary School Students Irawan, Sonny; Iasha, Vina
Buana Pendidikan Jurnal Fakultas Keguruan dan Pendidikan Universitas PGRI Adi Buana Surabaya
Publisher : Fakultas Pedagogi dan Psikologi Universitas PGRI Adi Buana Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36456/bp.vol17.no2.a3942

Abstract

This research is aimed to reveal the effects of the core learning model and mathematical disposition model to problem-solving skills in elementary school. This research is experimental research with a 2x2 factorial design. The research sample is fourth-grade students, i.e., 44 persons. The instrument is the mathematical disposition and problem-solving skill instrument. The research result shows that the core learning model is a suitable mathematical learning model to develop mathematical problem-solving skills. The core learning model is more appropriately applied on a group of students with a high mathematical disposition. Meanwhile, the conventional model is more suitable to be applied on a group of students with a low mathematical disposition
Optimization of Well Placement Based on Reservoir Fluid Contact Irawan, Sonny
Journal of Earth Energy Science, Engineering, and Technology Vol. 7 No. 3 (2024): JEESET VOL. 7 NO. 3 2024
Publisher : Penerbitan Universitas Trisakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25105/6bwf7771

Abstract

The development of oil fields was often troubled with the predicament of figuring the optimum well location, been it vertical or horizontal wells. The process of hydrocarbon resources extraction from a reservoir which was economically effective is required for producers and injectors to drilled and positioned at an optimal location. One of the contributing factors of decided an optimized location of well is reservoir fluid contact, gas-oil contact (GOC) and oil-watered contact (OWC). Reservoir overlying a strong aquifer typically had high watered cut thus impairing oil production rate also, leads to water coning. The optimized location of well could have affected by water coning mechanism in oil-water and gas-water system differently due to the density difference of the hydrocarbon. Water coning due to increased water cut in the OWC region is the most common phenomena therefore, the purpose of this studied is to observed water cut increment along production period. Besides, monitoring downhole well constraint in water cut and production rate estimation could also be done in ordered to estimate optimal location or placement of horizontal well with respect to GOC and OWC. Vertical and horizontal well placement is simulated with varying downhole constraints to ensured efficient production rate of hydrocarbon. Therefore, estimation of water cut and breakthrough timed is conducted after increased in water cut thus, oil production rate and oil recovery factor against water cut increment could be generated to illustrate which well showed highest productivity and efficiency.
Characterization of Porang and Xanthan Gum Solutions for Polymer Flooding Sutiadi, Andrian; Siahaya, Jacob; Maulida, Fajri; Mardiana, Dwi Atty; Fathaddin, Muhammad Taufiq; Setiati, Rini; Rakhmanto, Pri Agung; Irawan, Sonny
Journal of Earth Energy Engineering Vol. 13 No. 2 (2024)
Publisher : Universitas Islam Riau (UIR) Press

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Porang tubers contain glucomannan which is used in various industries. Porang is a biopolymer that has the potential to be applied in polymer flooding in oil reservoirs. In this research, a combination of porang and Xanthan gum was used for displacing oil in the laboratory. The samples analyzed varied with polymer concentrations of 2000, 4000, and 6000 ppm respectively for porang solution, Xanthan gum, and a mixture of porang and Xanthan gum. The salinity of the formation water used in this research was 6000, 12000 and 18000 ppm. The experiment aimed to observe the characteristics and performance of porang and Xanthan gum including testing for compatibility, viscosity, adsorption and sandpack flooding. Based on the test results, all samples were compatible. The application of a mixture of porang and Xanthan gum provided lower adsorption compared to the application of only Xanthan gum. The highest reduction in adsorption value given was 3.545 mg/gr. The highest viscosity and additional recovery factor were given by a mixture of porang and Xanthan gum with a concentration of 6,000 ppm and a salinity of 18,000 ppm, namely 284.72 cP and 16.1%, respectively.
Evaluation of Indonesia's Upstream Oil and Gas Fiscal Terms in Comparison to Malaysia's Enhanced Profitability Terms (EPT)Case Study of Block X Exploration Field Halim, Yosep; Rakhmanto, Pri Agung; Mardiana, Dwi Atty; Irawan, Sonny; Lalaina, Ramefivololona Hanitra; Aimé, Rajomalahy Julien; Fifaliana, Razakamampianina Valisoa; Harifenitra, Ravololoarimanana
Journal of Earth Energy Science, Engineering, and Technology Vol. 8 No. 1 (2025): JEESET VOL. 8 NO. 1 2025
Publisher : Penerbitan Universitas Trisakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25105/hsn4wb37

Abstract

Oil and gas sector is one of the main drivers of Indonesia's economy. Thus, it is important to ensure the attractiveness of Indonesia's Production Sharing Contracts (PSC) fiscal terms for investment, especially in comparison with neighboring countries. In 2021, Malaysia introduced the Enhanced Profitability Terms (EPT) PSC, which is considered to provide a better and more reasonable return for oil and gas contractors. The purpose of this study is to analyze and compare the attractiveness of the Cost Recovery and Gross Split fiscal terms in Indonesia with the EPT fiscal terms in Malaysia, based on economic indicators, including their sensitivity. This study uses a quantitative approach by calculating the economic viability of fields (NPV, IRR, POT), their sensitivity, the range of %CT and %GT, and the profitability characteristics of an exploration block field (Block X). From the evaluation and comparison conducted (specific to the assumed case), it was concluded that the Indonesian Gross Split PSC and the Malaysian EPT PSC have improved economic indicators compared to the Indonesian Cost Recovery PSC. Therefore, the Indonesian Gross Split PSC and the Malaysian EPT PSC generally have better economic indicators, including sensitivity to changes in oil prices, operating costs, and production levels, compared to the Indonesian Cost Recovery PSC. To obtain a more complete picture and enrich the evaluation of these fiscal terms, further analysis can be conducted by considering business risks of contractors, simulations with the application of incentives, and other factors that can affect investment decisions.
Modeling and Prediction of Kappaphycus alvarezii Viscosity Using Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System Fathaddin, Muhammad Taufiq; Ridaliani, Onnie; Rakhmanto, Pri Agung; Mardiana, Dwi Atty; Septianingrum, Wydhea Ayu; Irawan, Sonny; Abdillah, Ridho
Journal of Earth Energy Science, Engineering, and Technology Vol. 8 No. 3 (2025): JEESET VOL. 8 NO. 3 2025
Publisher : Penerbitan Universitas Trisakti

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25105/fh90e382

Abstract

This study examines the viscosity behavior of Kappaphycus alvarezii polymer solutions enhanced with TiO2 nanoparticles under varying concentrations, salinity, and temperature. Predictive models were developed using Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) approaches. The experimental work involved preparing Kappaphycus alvarezii solutions with polymer concentrations ranging from 2,000 to 6,000 ppm and TiO2 nanoparticle concentrations from 2,000 to 4,000 ppm at salinities of 6,000–30,000 ppm and temperatures between 30 °C and 80 °C. Results showed that increasing Kappaphycus alvarezii concentration enhanced viscosity by 1.04–21.12%, while TiO2 nanoparticles improved viscosity stability, especially under high-salinity conditions. In contrast, higher salinity and temperature reduced viscosity due to ionic screening and increased molecular motion, although a slight rise was observed at 30,000 ppm salinity. The optimized ANN model (18 neurons, one hidden layer) achieved a superior correlation coefficient (r = 0.9980) compared to ANFIS (r = 0.8769), confirming higher predictive accuracy. These findings demonstrate the potential of Kappaphycus alvarezii–TiO2 nanofluids as sustainable viscosity modifiers for enhanced oil recovery (EOR) and verify the reliability of ANN and ANFIS models in predicting viscosity under complex multivariable interactions.