Landslides in Bone Bolango Regency have increasingly impacted the population, with data showing a rise in affected areas from 2020 to 2021. To mitigate these risks, mapping areas with potential landslides is crucial for providing early warnings, although such efforts remain incomplete. Therefore, this research aims to determine the potential for landslides in Bone Bolango Regency, especially in Suka Damai Village. The geophysical method used in this research is the geomagnetic method because it utilizes the magnetic properties of rocks below the surface and can interpret subsurface structures in areas with the potential for landslides. Based on the research results, it was identified that the research location is dominated by diorite and granodiorite igneous rocks, where diorite rocks dominate from the surface to a depth of 40 meters with a susceptibility contrast value of 3 – (2.5) SI. Meanwhile, granodiorite rocks are found at a 20 – 110 m depth with a susceptibility value of 1.5 – 3 SI. Based on 3D visualization, it was found that diorite rock acted as landslide material, and granodiorite rock acted as sliding rock. Besides that, material movement forms slopes caused by shear failure that occurs along one or more landslide planes. This research confirms that the research area is a potential landslide area with a level of stability in category D, which means it is less stable.
A DSSC has a good performance seen from the ability of the photoanode to absorb sunlight. The use of photoanodes uses a semiconductor material, namely ZnO. However, in use, ZnO has the disadvantage of low optical and electrical properties, which results in low DSSC efficiency. So in this research, efforts are made to add Cu-Ag double doping to improve optical and electrical properties that will increase the efficiency of DSSC. ZnO/Cu-Ag photoanodes were prepared using the sol-gel spin coating method with doping variations of 0%, 1%, 2%, and 3%. Characterization was carried out using a UV-Vis spectrophotometer to see the absorption area and determine the band gap energy of the ZnO photoanode. I-V Keithley was used for current and voltage characterization to determine the conductivity of the ZnO photoanode and the efficiency of the DSSC. The results of the research show the effect of increasing the optical properties of ZnO photoanodes by decreasing the band gap energy along with the increase in doping concentration, namely 3.29 eV, 3.24 eV, 2.44 eV, and 2.40 eV. In addition, there is an increase in conductivity on the ZnO photoanode with the highest conductivity at doping concentration of 3% which is 0.1006 Ω-1m-1 with an increase of 6 times compared to the pure ZnO photoanode of 0.0163 Ω-1m-1. The improved optical and electrical properties of ZnO/Cu-Ag photoanodes have an impact on increasing the efficiency value of DSSC with the optimum efficiency achieved at 1% doping concentration of 0.0291% with an increase of 16 times compared to the use of pure ZnO photoanode of 0.00018%. The addition of Cu-Ag doping to ZnO improves the optical and electrical properties of the photoanode, enhancing DSSC efficiency with an optimum at 1% doping concentration.
The island of Java is an interesting place to study geology because of the various tectonic processes that occur starting from volcanic activity, changes in relief, and the relative movement of faults. The aim of this research is to determine the distribution of geological structures spread throughout Java Island based on fault analysis from gravity satellite data. Gravity data was taken via the ICGEM website with a data resolution of 2 km so that 10,000 data were obtained consisting of gravitational disturbances (GD), geoid, and Digital Elevation Model (DEM). The data processing results represent weak zones on the residual anomaly map where fault movement occurs with low anomaly values, namely -55,147 – (-27,175) mGal which stretches from West Java to southern Madura. On the FHD map, it can be seen that the distribution of maximum gravity anomalies is quite numerous and complex with an anomaly value of 1117.18 mGal. It is suspected that the fault near the mountain occurred due to volcanic processes and the southern part occurred due to the shifting process of the Indo-Australian plate and the Eurasian plate. On the TDR map, the weak zones caused by faults spread across Java Island have low gravity anomaly values ranging from -1,353 – (-0.833) mGal. In the Banten to West Java area there are the Baribis Fault and the Cimandiri Fault. In the Central Java region there are the Ajibarang, Ungaran, Baribis Kendeng and Pati faults, as well as parts of the Special Region of Yogyakarta there is the Opak fault. Meanwhile, in the East Java area there are the Baribis Kendeng, Pasuran and Probolinggo faults.
This research provides an in-depth examination of the physicochemical parameters of borehole water samples in Borokiri Port Harcourt, with an emphasis on temperature, pH, conductivity, total dissolved solids (TDS), and heavy metal concentrations (lead, copper, zinc, and manganese). This research objective is to undertake a complete hydrogeochemical evaluation of groundwater quality in Borokiri, with an emphasis on determining the levels of various physicochemical parameters and heavy metal pollutants. The study included comprehensive field surveys, collecting primary data at borehole locations. Samples were gathered during the rainy season, analyzed in Borokiri's laboratory for physicochemical and microbial parameters using established international methods. Data analysis employed various geochemical techniques, ensuring a thorough assessment of groundwater characteristics and quality. The mean temperature, roughly 29.97°C, is surrounded by a tight clustering, with a modest temperature range of 6.30°C. The average pH of 8.04 shows excellent constancy, as seen by a low standard deviation and a limited range. Conductivity has a mean of 417.00 S/cm, showing significant dispersion with a wider range. The mean total dissolved solids of 199.00 mg/L demonstrate a wide range. Piper and Durov diagrams reveal ion dominance and interaction among samples, supporting judgements on water resource management. The calculated Water Quality Index (WQI) values represent the status of water quality, with most samples displaying "Good" quality and one indicating "Poor" quality due to increased parameter concentrations.
Marine seismic data recordings consist of signals and various types of noise which can reduce the quality of the resulting data processing model. This research purpose to increase the signal to noise ratio of a 2D seismic cross-section using the demultiple and stacking methods. This research method applying the Common Reflection Surface (CRS) stack method with a combination of two seismic noise demultiple methods, namely Surface Related Multiple Elimination (SRME) and Wave Equation Multiple Rejection (WEMR) using ProMAX software. The CRS stack results has been proven to be able to eliminate random noise, increase amplitude, and clarify existing reflector patterns. The radon analysis feature can also assist the data quality control process related to the presence of multiple noise indications. The SRME and WEMR demultiple results can predict different multiple models so that later they can be subtracted from the main data. The multiple SRME prediction results is characterized by shape, size and wavelet pattern, whose overall trace appearance tends to be similar and not too complex. The multiple WEMR prediction results has characteristics of shape, size and wavelet pattern whose overall trace is almost similar and slightly more complex. The combination of the CRS, SRME, and WEMR stack methods is concluded to be able to reduce the presence of noise, so that the main reflector pattern is easier to identify as the actual subsurface layer. However, there are still indications of the existence of multiple residues that have not been completely reduced. Therefore, further research is needed, especially in combining the CRS stack, F-K filter, Radon filter, SRME, and WEMR methods.
