Integrasi Metode Resistivitas, Seismik Refraksi, Geologi Berbasis Geospasial untuk Identifikasi Potensi Longsor di Srimartani, Yogyakarta

Kabupaten Bantul merupakan salah satu kabupaten yang berpotensi terjadi tanah longsor, tepatnya di daerah Srimartani, Kecamatan Piyungan. Penelitian ini dilakukan dengan tujuan untuk mendapatkan data dan informasi mengenai parameter metode geofisika daerah longsor dan mengetahui dugaan zona potensi longsor. Metode yang digunakan dalam penelitian ini adalah survei lokasi, akuisisi metode seismik refraksi, akuisisi metode resistivitas, dan pemetaan foto udara (geospasial). Dari penampang bawah permukaan seismik refraksi metode hagiwara didapatkan bahwa lapisan lapuk pada daerah riset berupa soil dan pasir tuffan dikarenakan memiliki sifat permeable dan bidang gelincirnya yang bersifat impermeable. Pada penampang bawah metode seismik refraksi lapisan pertama yaitu soil dengan kecepatan V1 sekitar 313.8 m/s – 461.6 m/s dan lapisan kedua yaitu pasir dengan kecepatan V2 sekitar 459 m/s – 1567 m/s. Sementara penampang bawah permukaan metode resistivitas konfigurasi dipole – dipole didapatkan lapisan lapuk tersebut memiliki nilai resitivitas yang kecil dikarenakan lapisan tersebut bersifat lunak sehingga ada kemungkinan lapisan tersebut dalam kondisi basah. Pada penampang resistivitas memiliki nilai 126 ohm.m hingga lebih dari 301 ohm.m, daerah tersebut diperkirakan terdapat batuan breksi batuapung dari formasi semilir yang diduga sebagai bidang gelincir. Dari segi geologi, daerah penelitian sangat rentan terjadi tanah longsor dikarenakan kondisi lereng searah dengan kondisi struktur regional di daerah penelitian yaitu barat-timur, didukung oleh kondisi batuan yang ada berupa breksi batuapung dan tuff yang sangat rawan terjadi longsor. Dengan adanya penelitian ini, diharapkan dapat menambah pengetahuan mengenai antisipasi masyarakat dalam meminimalisir dampak yang ditimbulkan dari adanya tanah longsor. Bantul Regency is one of the districts that have the potential for landslides to occur, precisely in the Srimartani area, Piyungan District. This research was conducted with the aim of obtaining data and information about the parameters of the geophysical method of landslide areas and knowing the alleged landslide potential zone. The methods used in this research are site survey, seismic refraction acquisition method, resistivity method acquisition, and aerial photography (geospatial) mapping. From the subsurface seismic refraction of the Hagiwara method, it was found that the weathered layer in the research area was soil and sand due to its permeable properties and impermeable slip plane. . In the lower section of the seismic refraction method, the first layer is soil with a V1 velocity of around 313.8 m/s – 461.6 m/s and the second layer is sand with a V2 velocity of about 459 m/s – 1567 m/s. While the subsurface resistivity method of the dipole - dipole configuration found that the weathered layer has a small resistivity value because the layer is soft so there is a possibility that the layer is in a wet conditionIn the cross section resistivity has a value of 126 ohm.m to more than 301 ohm.m, the area is estimated to contain pumice breccia from the breccia formation which is thought to be a slip plane. In terms of geology, the research area is very susceptible to landslides because the slope conditions are in line with the regional structural conditions in the research area, namely west-east, supported by the existing rock conditions in the form of pumice breccia and tuff which are very prone to landslides. With this research, it is hoped that it can increase knowledge about community anticipation in minimizing the impact of landslides.

Dislocation Topological Evolution and Energy Analysis in Misfit Hardening of Spherical Precipitate by the Parametric Dislocation Dynamics Simulation

Interaction of a single dislocation line and a misfit spherical precipitate has been simulated by the Parametric Dislocation Dynamics (PDD) method in this research. The internal stress inside the precipitate is deduced from Eshelby’s inclusion theory, the stress of the dislocation line and outside the precipitate is calculated by Green’s function. The influence of different relative heights of the primary slip plane on dislocation evolution is investigated, while the cross-slip mechanism and annihilation reaction are considered. The simulation results show three kinds of dislocation topological evolution: loop-forming (Orowan loop or prismatic loop), helix-forming, and gradual unpinning. The dislocation nodal force and the velocity vectors are visualized to study dislocation motion tendency. According to the stress–strain curve and the energy curves associated with the dislocation motion, the pinning stress level is strongly influenced by the topological change of dislocation as well as the relative heights of the primary slip plane.

Internal Stress and Dislocation Interaction of Plate-Shaped Misfitting Precipitates in Aluminum Alloys

The fine misfit precipitates in age-hardenable aluminum alloys have important roles due to their excellent age-hardening ability, by their interaction with dislocations. The present study focused on the internal stress field of plate-shaped misfitting precipitates to evaluate their roles in dislocation overcoming the precipitates by means of micromechanics based on Green’s function method. The stress field of misfit precipitates on {001} and {111} habit planes were reproduced by homogeneous misfit strain (eigenstrain) of the precipitate (Eshelby inclusion method), and the dislocation motion vector on the primary slip plane was predicted by the force acted on the dislocation by the Peach–Koehler formula. According to simulation results, the dislocation interaction strongly depends on the stress field and geometry of misfit precipitates; repulsive and attractive forces are operated on the dislocations lying on the primary slip plane when the dislocation approaches the misfit precipitates. The hardening ability of different orientations of precipitation variants was discussed in terms of interaction force acted on the dislocation.

Geoelectric Method Application of Dipole-Dipole Configuration for Identification of Landslide Prone Areas in Poka Village, Ambon

Landslide disaster is one type of disaster that often occurs in Indonesia which causes many casualties and loss of property. Ambon City is an area with high potential for landslides. This is because Ambon City is an area with steep slopes and high rainfall, so a study is needed to overcome this as a disaster mitigation effort. This study aims to determine the area of landslide slip and direction of landslides as a basis for identifying landslide-prone areas using the dipole-dipole configuration geoelectric method. This research was conducted in Poka Village, Ambon City, Maluku Province. Geoelectric measurements using the AGI Ministing tool with data retrieval as much as 5 tracks. Based on the results of the analysis, it was found that the soil layer was dominated by clay and limestone. The reconstruction results show that the topography of the area is a slope with a slope of 45o-80o, and the slip plane has each path with a resistivity contrast of ± 25-60 Ωm at a depth of 5-15 meters, while the direction of the landslide is directed to the southeast.

Probing anisotropic mechanical behaviour in carbamazepine form III

Nanoindentation measurements in single crystals of carbamazepine form III show that the (020) face is stiffer and harder than the (002) and (101) faces. AFM imaging and molecular simulations reveal that the (020) plane is the most likely slip plane.