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Indonesia commits to reducing emissions by 29% (unconditional) or 41% (conditional) in 2030, which can be achieved by encouraging the use of new and renewable energy (NRE) by 23% in 2025 while realizing national energy security. A biofuel development plan through a mandatory biodiesel program and green fuel utilization is the main priority to reduce fossil fuel consumption and achieve the energy mix target. As of January 1, 2020, through the mandatory biodiesel program, biodiesel utilization reached 30% (B30) for all diesel engine sectors, which is the highest biodiesel blending program in the world. However, the gap between government policies with emission regulation and existing vehicle technologies in this country might provide challenges in strengthening the sustainability of mandatory biodiesel programs. This study used a normative juridical method to assess the policy and enhance the regulation of the mandatory biodiesel program by obtaining library materials, theories, concepts, principles, and existing rules related to the law perspective. An appropriate and consistent energy mix policy, including its long-term strategy to increase biofuel utilization and maintain a mandatory biodiesel program, is needed to achieve a reducing emissions target. It is essential to strengthen and clarify the policy and road map. The vehicle technology and fuel quality were also crucial for enhancing emission regulation and eliminating low-quality fuels, maintaining a sustained biodiesel program, and achieving national energy security.

We discussed a method to accelerate an adiabatic quantum dynamics of XY spin model by using the fast-forward method proposed by Masuda and Nakamura. The Accelerated scheme is constructed by adding the driving Hamiltonian to the original Hamiltonian and speeding it up with a large time-scaling factor and an adiabatic parameter that realizes adiabatic quantum dynamics in a shortened time. Accelerated adiabatic dynamics start by assuming the candidate of driving Hamiltonian consists of the pair-wise exchange interaction and magnetic field. The driving Hamiltonian terms multiplied by the velocity function together with the original Hamiltonian give fast-forward driving for adiabatic states. We apply our method to XY spin model by considering three spin systems on the Kagome lattice. In this model, we obtained the XY pair-wise exchange interaction of nearest neighbors and next-nearest neighbors should be added to the original Hamiltonian as a driving interaction to accelerate the adiabatic motion. This pair-wise driving interaction in the fast-forward scheme guarantees the complete fidelity of accelerated states.

We have analysed the recently extended series for the number of self-avoiding walks (SAWs) $C_L(1)$ that cross an $L \times L$ square between diagonally opposed corners. The number of such walks is known to grow as $\lambda_S^{L^2}.$ We have made more precise the estimate of $\lambda_S,$ based on additional series coefficients provided by several authors, and refined analysis techniques. We estimate that $\lambda_S = 1.7445498 \pm 0.0000012.$ We have also studied the subdominant behaviour, and conjecture that $$ C_L(1) \sim \lambda_S^{L^2+bL+c}\cdot L^g,$$ where $b=-0.04354 \pm 0.0001,$ $c=0.5624 \pm 0.0005,$ and $g=0.000 \pm 0.005.$ We implemented a very efficient algorithm for enumerating paths on the square and hexagonal lattices making use of a minimal perfect hash function and in-place memory updating of the arrays for the counts of the number of paths. Using this algorithm we extended and then analysed series for SAWs spanning the square lattice and self-avoiding polygons (SAPs) crossing the square lattice. These are known to also grow as $\lambda_S^{L^2}.$ The sub-dominant term $\lambda^b$ is found to be the same as for SAWs crossing the square, while the exponent $g = 1.75\pm 0.01$ for spanning SAWs and $g = -0.500 \pm 0.005$ for SAPs. We have also studied the analogous problems on the hexagonal lattice, and generated series for a number of geometries. In particular, we study SAWs and SAPs crossing rhomboidal, triangular and square domains on the hexagonal lattice, as well as SAWs spanning a rhombus. We estimate that the analogous growth constant $\lambda_H=1.38724951 \pm 0.00000005,$ so an even more precise estimate than found for the square lattice. We also give estimates of the sub-dominant terms., Comment: 58 pages, 30 figures

This study aimed to determine the influence of storage on the structural damage of vegetable-tanned goat skin by microbes. The storage time was divided into three treatments, namely treatment P0 (0 months, storage), treatment P1 (6 months, storage), and treatment P2 (12 months, storage). The observation parameters for investigation included microbe contamination, pH levels, and levels of oil/fat. This study was conducted with Analysis Variance Completely Randomized Design (ANOVA) and Duncan Multiple Range Test (DMRT) to determine the differences between treatments. In contrast, analysis regression was used to obtain the optimum level. The research found that the highest amount of microbial contamination on the leather occurred at month 12, with the amount of microbial contamination reaching 4.46x103 CFU. The best storage for pH levels occurred at month 14 and pH 5.16. The skin with the best oil content is in the third month, with an oil/fat content of 7.97%.

The middle phase emulsion is the most important parameter in the compatibility test that determines the success of the surfactant in the Enhanced Oil Recovery (EOR) process. The purpose of this research was to observe the mid-phase emulsion formed on the use of Sodium Lignosulfonate (SLS) surfactant at various concentrations. One of the compatibility tests that will be used is the phase behavior test. Phase Behavior is carried out to determine whether SLS surfactant forms a middle phase emulsion when used in a crude oil. The method used in the phase behavior test is 2 mL of surfactant solution with a certain concentration mixed with 2 mL of crude oil which is inserted into a scaled test tube. Then the surfactant and crude oil solution in the test tube was shaken slowly. During the test, the test tube was placed in an oven at a temperature of 60° C for 21 days. The first observations were made during the first shaking process, then observed at 30 minutes, 60 minutes, 2 hours, 1 day, 2 days, 7 days, 14 days and 21 days. The formation water salinity were used at 40,000 ppm, 60,000 ppm and 80,000 ppm. From the results of this phase behavior test, the best mid-phase emulsion was formed at a surfactant concentration of 2.5% at 40,000 ppm of formation water salinity with an emulsion value of 11.3%. While the 60,000 ppm and 80,000 ppm formation water salinity formed the upper phase emulsion. From this research, it can be concluded that the formation of the middle phase emulsion of SLS surfactant bagasse in the intermediate crude oil was influenced by the salt content of the formation water used.

Home Industry has a positive impact on absorbing labor, but is still lacking in supervision. Bakpao Arum Jaya’s home industry is a small-scale industry that uses noise-producing equipment. The purpose of this study is to determine the description of noise intensity when the machine is working during the production process. This research uses the quantitative descriptive method. The data used are primary data from field measurements and secondary data. The measurement points were carried out in the grinding room and steam area. The results showed that the Leq of the milling room was 89.36 dB(A) which exceeded the TLV and the Leq of the steam area was 77.34 dB(A) which did not exceed the TLV. Playing music through speakers can also increase the noise in the work area. In the steam area, if measurements are taken on three steam equipment that is turned on simultaneously, the noise value will be greater than the measurement results and may exceed the allowable TLV. Exposure to noise every day will have an impact on health problems for workers. Forms of mitigation that can be done are administrative mitigation, worker health checks, use of protective equipment, and reducing noise from the source.

In the realm of urban planning and design practice, understanding urban morphology can be the basis for the physical development of the built environment that is adaptive and transformative to the uncertain and rapid changes in urban areas. This study aims to identify the physical form that is expected to represent the character of the development of Indonesia’s urban areas in Yogyakarta as the ‘Inner City’ and Semarang as a ‘Coastal City’. The research used an NDBI map within two different timescales to identify the figure and ground of both case studies to generalize the urban tissue pattern. The initial results show that the two districts have a similar tendency to develop heterogeneously and dispersed with the predominant configuration of figures arranged through field blocks and open system urban fabric. However, the two districts also have differences that represent the physical characteristics of the inner city in the form of a low-density continuous development pattern and a coastal city in the form of a linear development pattern. The characters show the process of shifting from closed urban fabric to open-fragmented peri-urban fabric.

This paper reports the fatigue analysis for a failure of a shaft in a wind turbine in which reinforced-welding elbow to support the shaft load. The shaft was broken near the reinforcing elbow. When designing mechanical and structural components, the diameter and the characteristics of materials have been considered not to exceed the permissible limit. However, after 40 days of the cycle operation, the shaft was broken at the accepted loading conditions within reasonable limits at a wind speed of 6-10 m/s. The crack initiate fatigue in the shaft is influenced by many variables that may due to uniaxial, bending, torsion, the shape of loading curve, part size, part finish, operating temperature, and atmosphere. For these reasons, it is important to investigate the fatigue behavior on the failure of the shaft. The main goal is to investigate and analyze the fatigue behavior on a broken shaft of the wind turbine gearbox to determine the features that cause the failure. A microscopic investigation of the fatigue-fracture surface was done. The microscopic analysis was carried out in terms of the chemical composition using ARL Spark Spectrometer, energy dispersive spectroscopy (EDS), the morphology of the fatigue by using scanning electron microscopy (SEM) and hardness test. Moreover, a theoretical analysis was made to illustrate the results and comparison between these results and the corresponding stress distribution data from a finite element method (FEM) simulation to know how the fatigue fracture began and propagated along the shaft. The result of the analysis shows that the fatigue occurred due to the unbalanced of the bending and torsion stress in the junction of the reinforced-welding elbow with hardness testing at the extreme cracking area is 435 HV. It is emphasized that the microstructure of fatigue surface structure shows sensitization to facilitate intergranular cracking and fatigue corrosion.

The depletion of solid fuels in the world triggers the requirement for the existence of an alternative fuel product as a substitute. In several studies, briquettes have become one of the alternatives used to deal with this problem. However, the selection of briquette material that considers its impact on economic, social, and environmental aspects has not been widely carried out. To solve this problem, the selection of raw materials for briquettes must be determined using the concept of sustainable product development (SPD). SPD is a concept that can be used to determine a new product by considering various aspects, including economic, environmental, and social aspects. Briquette fuel that is derived from leaf waste and rejected fruit as a binding agent can be an alternative to renewable solid fuels since the raw materials come from wastes that have no selling value. The methodology used in this research is by conducting a survey at five markets in Surabaya and proceeding with interviews with the local government official. Pugh Matrix Concept Selection (PMCS) method is used to determine the suitable raw materials and to analyze the sustainability of the product development. Through PMCS, the results show that the best material for briquette production based on economic, social, and environmental aspects is a mixture of Samanea saman leaf waste with a 12.83 rating value and rejected papaya as the binding agent with a 10.44 rating value. Briquette with a mixture of 95% Samanea saman leaf waste and 5% rejected papaya is produced with a mesh size of 60 or 250 μm and a compression pressure of 2 MPa and is identified to have a heating value of 4025.87 Kcal/Kg.

This paper is about the selection process of packaging design for liquid organic fertilizer made of chicken slaughterhouse waste in South Jakarta. The purpose of using packaging is to contain, transport, protect, provide product-related information, and market the product. The research aims to determine the most appropriate design, additional features, and the type of plastic as the liquid organic fertilizer container that applies the reverse logistics concept: refillable. Quality Function Deployment (QFD) is applied to select the best packaging type that fulfils consumers’ requirements. This QFD method analyses the features and helps to select the best design out of various liquid container designs available in the market. The results showed that the liquid organic fertilizer to be used is made of thick High-Density Polyethylene (HDPE) plastic bottle with sprays on its screw-type lid that enables the reverse logistics concept.

In this paper we consider the central force problem in the special theory of relativity. We derive the special relativistic version of the Binet equation describing the orbit of a massive body. Then, the motion of a planet in a solar-like system where the gravitational potential is modified by adding a term that is proportional to the inverse of the square of the radial coordinate is discussed. Using perturbative method, we obtain the explicit orbital function. At the end, the orbital precession of the planet and its relation to the result from general relativity are also discussed.

Acacia (Acacia crassicarpa) is a fiber source for pulp industries, adaptive on tropical peatlands and has been planted intensively since the early seventies. Considering the fragility of peat and its low nutrient content along with the complication to manage water conducive environment to the tree growth, the sustainability of this plantation is under rudimentary inquiry. Peat loss may occur due to subsidence, emission, and surface runoff whilst biomass accumulation will result in carbon enhancement. This study aims 1) to evaluate growths of Acacia trees planted on tropical peatlands with different peat thicknesses; 2) to obtain allometric model to represent the growth of the tree parts; and 3) to estimate biomass and carbon accumulations and their rate in a few rotations. Destructive samples were taken from three different sites with different peat thicknesses and separated into the root, knud (buttress root), stem, branch, and leaf. An allometric model was introduced to represent each growth of the tree parts and to estimate the accumulation of biomass and carbon. The result shows Acacia grew better in thick peatlands, larger than 1 meter. The model can relate the tree parts specifically to estimate the tree biomass. In one hectare of one rotation within 5 years, total biomass ranges 36.3–443.7 tonnes, and total carbon absorbed ranges 17.4–213.0 tonnes. Thus, successive rotations would potentially result in additional thickness of organic matter at the rate of 0.07– 2.08 cm/y, and carbon enrichment at the rate of 1.74–19.98 tonnes/y. This biomass and carbon enrichments would lessen the losses and greenhouse gas emission from the peatlands.

In this study, we performed Molecular Dynamics (MD) Simulation to investigate the significance of diameter during heat treatment of Aluminum nanoparticle. Structure information along with thermodynamics evolution is analyzed to explain the significance. Different sizes of nanoparticle diameter, i.e., 5 nm, 10 nm, and 15 nm, were investigated with same heating rate. The results show that smallest diameter is suffered for total melting, while for larger nanoparticle small fractions remains. Thermodynamics information indicated the relation that smaller diameter will experience faster pressure oscillations period. While for larger system, the period is longer, but the pressure value become stronger. Structure analysis confirmed that the nanoparticles are melted at the end of the simulation.