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Energy transitions as socio-technical processes involves interactions among different actors such as households, firms, and government, thus requiring an integrated approach to explore the transition's dynamics. The present study aims to simulate the socio-technical transitions of photovoltaics (PV) in Indonesia using an empirically based hybrid simulation-optimization model. The model involves households' decision-making, PV supply chain, and government interventions. The hybrid simulation-optimization model consists of integer linear programming to optimize PV's supply chain configuration which was embedded within agent-based modeling and simulation (ABM). The empirical data involving 413 households from 34 provinces in Indonesia was acquired from a survey that was specifically designed based on the Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) to specify and parameterize the model. Export tariff regulation, incentives for PV investment, environmental campaigns, and the combinations of those interventions were evaluated. The findings demonstrate that all of the interventions increase the intention toward PV, but the intention is not necessarily translated into adoption due to either financial or facility constraints. The findings highlight the necessity to include both demand and supply aspects endogenously in the transition model. The export tariffs combined with the incentives, followed by the export tariffs combined with the campaigns, is found to be preferable due to low supply chain unit cost and high reduction of greenhouse gas. Managerial implications and future research are discussed. [ABSTRACT FROM AUTHOR]

This paper describes a numerical model based on discontinuous Galerkin method for thermoacoustic investigation. Numerical investigation was conducted to study the behaviour of thermoacoustic wave propagations induced by thermal effects in 2-dimensional enclosure. The compressible Navier-Stokes equations are used as the governing equations. The spatial domain was discretized by using unstructured discontinuous Galerkin method and the explicit fourth-order Runge-Kutta was used to integrate the temporal domain. The accuracy of the numerical results was assessed against other numerical methods and linear solutions. The comparisons with linear solutions show excellent agreement and comparisons with flux corrected transport (FCT) method show fair agreement. [ABSTRACT FROM AUTHOR]

Indonesia is blessed with numerous variants of energy resources; both renewable and nonrenewable sources. From the plethora of alternatives, natural gas is among those energy resources which are gaining popularity, as evidenced by the significant increase in demand in recent years. Unfortunately, however, this positive increase in demand is not equally followed with the sufficient supply of natural gas. This consequently leads to a gap between the supply of natural gas and the increasing demand from the market. In order to equalize this disparity between supply and demand, numerous experts have raised the idea of further regulating the natural gas aggregator to resolve this issue. This article will provide a general overview of the definition of natural gas aggregators contained under the draft presidential regulation regarding downstream gas management and to compare it with the existing definitions of natural gas aggregators. [ABSTRACT FROM AUTHOR]

We have developed a model capable of predicting the performance characteristics of a wiretype Joule-Thomson mici-ocooler intended for use within a cryosurgical probe. Our objective was to he able to predict cold tip temperature, temperature distribution, and cooling power using only inlet gas properties as input variables. To achieve this, the model incorporated gas equations of state to account for changing gas properties due to heat transfer witlun the heat exchanger and expansion within the capillary. In consideration of inefficiencies, heat in-leak from free convection and radiation was also considered and the use of a 2D axisynimetric finite difference code allowed simulation of axial conduction. To validate simulation results, we have constructed and conducted experiments with two types of microcoolers differing in inner tube material, poly-ether-ether-ketone (PEEK) and stainless steel. The parameters of the experiment were used in the calculations. CO2 was used as the coolant gas for inlet pressures from 0.5 MPa to 2.0 MPa. Heat load trials of up to 550 mW along with unloaded trials were conducted. The temperature measurements show that the model was successfully able to predict the cold tip temperature to a good degree of accuracy and well represent the temperature distribution. For the all PEEK niicrocooler in a vacuum using 2.0 MPa inlet pressure, the calculations predicted a tempel-ature drop of57 K and mass flow rate of 19.5 mg/s compared to measui-ed values of 63 K and 19.4 mg/s, therefo,-e, showing that conventional macroscale correlations can hold well for turbulent microscale flow and heat transfer as long as the validity of the assumptions is verified. [ABSTRACT FROM AUTHOR]