PERLINDUNGAN PETIR, SISTEM PENTANAHAN, DAN RESISTIVITAS TANAH: STUDI BIBLIOMETRIK

Increased lightning intensity generally causes an increase in the level of hazards such as infrastructure damage and death. To mitigate these hazards, research is necessary. Research developments can be seen from the various literature published in journals or books. This study aimed to quantitatively assess the development of research on lightning protection, grounding systems, and soil resistivity. The bibliometric method is used by searching based on keywords in the Scopus basis data, then visualizing it using VOSviewer. The results showed that the total identified publications were 706 publications all years, the first publication in 1967 and the highest in 2014-2020 with 481 publications (68.1%). The countries that dominate are China and Brazil. Universidade Federal de Minas Gerais was the most productive institution, while Silverio Visacro was the most productive writer. Engineering and energy are the most widely written subjects, while topics related to multidisciplinary are still rare (0.2%). Electric Power Systems Research Journal is the top journal that publishes this research topic. The publication progress map based on co-occurrences consists of 9 clusters. The few research topics include electrical safety, substation, and backfill materials, while current topics include towers, wind turbines, bentonite, natural enhancement materials, and electromagnetic models

GEOLOGI DAN PETROKIMIA ENDAPAN ZEOLIT DAERAH BAYAH DAN SUKABUMI

Zeolit dijumpai pada batuan piroklastik di daerah Cikembar (Sukabumi) dan Bayah (Banten) dari zona fisiografi pegunungan Bogor dan Bayah. Karakteristik, genesa batuan, dan tipe zeolit di kedua lokasi tersebut belum dijelaskan, terutama kaitannya dengan potensi pengkayaan unsur tanah jarang (UTJ) pada batupasir tufan di daerah Cikembar dan tuf teralterasi di daerah Swakan. Metode yang digunakan pada studi ini terdiri dari pengamatan geologi lapangan, petrografi, difraksi sinar-X (XRD), dan kimia batuan (whole rock) menggunakan XRF dan ICP-MS. Tujuannya adalah untuk mengungkap genesa pembentukkan zeolit dan UTJ di Swakan dan Cikembar. Batupasir tufan dari Cikembar dan tuf dari Swakan menunjukkan kehadiran zeolit bertipe mordenit dan klinoptilolit. Zeolit di daerah Cikembar terdapat sejajar perlapisan, sedangkan di daerah Swakan berasosiasi dengan kumpulan mineral alterasi. Pengendapan zeolit Cikembar dipengaruhi oleh air meteorik yang dicirikan oleh anomali negatif Ce pada pola diagram laba-laba yang di normalisasi terhadap kondrit. Total (∑UTJ) pada batupasir tufan dari Cikembar 82– 94 ppm dan pada tuf Swakan 71–83 ppm. Perbedaan kandungan ∑UTJ tersebut lebih mencerminkan komposisi UTJ pada batuan asal.ABSTRACT – Geology and petrochemistry of zeolite deposits of Bayah and Sukabumi areas. Zeolites are found in pyroclastic rocks in Cikembar (Sukabumi) and Bayah (Banten) from the Bogor and Bayah mountainous physiographic zones. The characteristics, rock genesis, and types of zeolites from these two locations have not been explained, especially in relation to the potential of REEs (Rare Earth Elements) enrichment in Cikembar tuffaceous sandstone and Swakan altered tuff. The method used in this study consists of field geological observations, petrography, X-ray diffraction (XRD), and whole rock geochemistry using XRF and ICP-MS. The aim is to uncover the formation of zeolites and REEs in Swakan and Cikembar. The Cikembar tuffaceous sandstones and the Swakan tuffs show the presence of mordenite and clinoptilolite types of zeolites minerals. The zeolites in Cikembar area are parallel to the bedding plane, while in Swakan area are associated with alteration mineral assemblages. The deposition of Cikembar zeolite was influenced by meteoric water which is characterized by the negative Ce anomalies in chondrite-normalized spider diagram pattern. The total (∑REEs) concentration in Cikembar tuffaceous sandstones are 82–94 ppm and Swakan tuffs are 71–83 ppm. The difference in the ∑REE content more likely reflects the parent’s rock REEs composition

Tropical Volcanic Residual Soil

In West Lampung, Sumatra, Indonesia, tropical volcanic residual soils are formed from weathering of volcanic breccias in hydrothermal alteration areas with a thickness of up to 20 m. This soil has the characteristics of clayey silt, low to high plasticity, brownish-red color, has the potential to swelling, easily eroded, and slide when it is saturated, and contains the minerals kaolinite, halloysite, illite, dickite, nacrite, montmorillonite, despujolsite, hematite, and magnetite. The results showed that this soil can cause corrosion of steel and is widely used by the community as a medium for growing plants and vegetables and as a foundation for infrastructure (for example, houses). The volcanic residual soil of the research area had Low Rare Earth Element (LREE) potential and specific uses. The soil with characteristic low plasticity has Liquid Limit (LL) brine value 50%, was more ideal for the primary forest

KARAKTERISTIK MINERAL LEMPUNG PADA JALAN RAWAN LONGSOR JALUR LIWA-BUKIT KEMUNING BERDASARKAN ANALISIS SEM DAN XRD

Tanah residu vulkanik jalur transek Liwa-Bukit Kemuning, Lampung Barat dijadikan objek penelitian dengan tujuan untuk mengetahui karakteristik mineral lempung yang terkandung. Analisis SEM dan XRD dilakukan terhadap lima sampel tanah permukaan. Berdasarkan kedua analisis tersebut mineral lempung yang hadir adalah kaolinite, illite, dan halloysite. Kaolinite memiliki karakteristik triklin, melembar dan berlapis. Illite memiliki karakteristik lembaran-lembaran menekuk dan menyerat. Sedangkan halloysite hanya hadir di analisis XRD

Characterization of Sedimentary Features of the 2018 Palu Tsunami Event, Sulawesi, Indonesia

We report the sediment features of the 2018 Palu tsunami in Indonesia based on the results of laboratory analysis. The mechanism for generating the 2018 Palu tsunami was a combination of an earthquake and a landslide, and several previous studies classified the tsunami as having a shorter wavelength and period. The characteristics of the deposits of tsunamis with shorter wavelengths and periods are not well recognized. We analysed samples of tsunami deposits along two transects on the east coast of Palu Bay. Grain size analysis showed that the deposits were generally fining upward along the transect, except for the seaward sites at Kayumalue. At both transects, grain sizes were mostly unimodally distributed. The organic and carbonate content in the tsunami deposits fluctuated, but in general the carbonates were higher in the tsunami deposits than in the pre-tsunami deposits. Organic matter tended to be higher in the pre-tsunami sediments. The content of geochemical elements also fluctuated. The content of foraminifera in the tsunami deposits was dominated by benthic species. The dominant sources of tsunami deposits were the transition to inner neritic zones, with minor contribution from pre-tsunami sediments. We conclude that the short-wave tsunami deposits of the Palu event are characterized by thin deposits with a dominant unimodal grain size distribution, sourced mostly from the shallow areas of Palu Bay