This study examines the inversion modelling of one-dimensional Schlumberger configuration resistivity data using the Very Fast Simulated Annealing (VFSA). Detailed identification and mapping of aquifer conditions is very important for the sustainable development of groundwater resources in an area. Vertical electrical sounding (VES) and surface electrical resistivity surveys have proven very useful for studying groundwater due to their simplicity and cost effectiveness. Global optimization inversion method also provides an inversion solution that is not expected to be trapped in a local minimum solution, so that it will get results that are closer to the actual situation. The VFSA method is inspired by phenomena in metallurgy related to the formation of crystals in materials caused by thermodynamic processes. This inversion scheme was tested initially with free noise synthetic data and with noise 5%. Furthermore, the program is applied to field data that has been measured in Ambon City, Maluku, Indonesia. The results of the VFSA inversion on field data obtained four layers consisting of top soil (141.2 ± 0,61 m) with a thickness of 1.43 m, andesite breccia rock (355.90 ± 0.46 m) with a thickness of 4 m, lapilli tuff (93.40 ± 0.31 m) with 30 m thick, then the last is the coarse tuff layer (34.30 ± 0.15 m) which is estimated as an aquifer.

Indonesia is one of the countries with the largest geothermal potential in the world, reaching 40% of the world's potential. In geothermal areas there are several layers such as overburden, reservoirs, fractures and heat sources. Subsurface fluid flow patterns in geothermal areas are a topic that is often discussed, especially for exploration purposes. Fluid flow basically uses the principles of Darcy's law, the principle of continuity and the Navier-Stokes equation. In solving this equation, a numerical approach can be used, where the results are close to the actual value. The numerical method used in this study is the finite element method, where the geometric domain is divided into smaller domains. The shape of the two-dimensional elements used is a non-linear triangle. The purpose of this study is to describe the pattern of fluid flow in porous media, especially in the case of geothermal areas and to determine the effect of rock permeability anomalies on fluid flow patterns. The results of modeling with the finite element method show that rock permeability affects the pattern of fluid flow. Liquid will flow at a higher velocity to an area of higher permeability.

Collisions between two objects can be analyzed using the concept of the law of momentum conservation. In the case of a collision between two objects, namely a bullet and a ball, it is necessary to analyze using a theoretical approach. This research aims to analyze the velocity and height after a collision. Newton's law of conservation of momentum and Newton's second law in friction conditions are used as the basis of Calculation analysis using analytical and numerical methods. There are air friction coefficients with variations of 0.1, 0.2, 0.3, 0.4, and 0.5 N.s/m. This type of bullet used a 9 mm calibre with a velocity of 380 m/s. The mass of the bullet and ball is 0.008 kg and 0.3 kg, respectively. The results showed that increasing the air fraction coefficient resulted in lower velocity and height achieved by bullet and ball. The increasing discretization value makes the results of numerical calculations consistent with analytical calculations.