Judul: Mapping the Habitat Suitability of the Sumatran Elephant (Elephas maximus sumatranus Temminck 1847) within Bukit Barisan Selatan National Park
Abstrak: Gajah adalah spesies kunci di Taman Nasional Bukit Barisan Selatan (TNBBS). Sebagai salah satu upaya konservasi spesies ini perlu dilakukan studi kesesuaian habitat. Tujuan penelitian ini adalah untuk memodelkan kesesuaian habitat dan mengidentifikasi faktor yang memengaruhi sebaran populasi gajah sumatera. Pemodelan habitat dilakukan menggunakan software Maxent, sedangkan variabel bebas yang digunakan adalah ketinggian, kelerengan, suhu, jarak dari jalan, jarak dari sungai, jarak dari perkebunan, jarak dari semak, jarak dari area terbuka, jarak dari pemukiman, serta tutupan lahan hutan yang diolah menggunakan software RStudio yang menghasilkan nilai class area, mean shape index, mean patch size, men patch fractal dimensional, dan number of patch. Titik kehadiran gajah diperoleh dari data sekunder GPS collar dari pihak BBTNBBS. Hasil pemodelan menunjukkan habitat yang sangat sesuai bagi gajah Sumatera di TNBBS yaitu seluas 16.901,61 ha dan 51.185,74 ha sebagai habitat yang sesuai. Beberapa faktor yang mempengaruhi kesesuaian habitat dan sebaran populasi gajah sumatera di TNBBS yaitu ketinggian, tutupan lahan hutan, dan jarak dari sungai., The Sumatran elephant (Elephas maximus sumatranus) plays a pivotal role as a keystone species within the Bukit Barisan Selatan National Park (BBSNP). Conservation efforts necessitate a thorough examination of its habitat suitability. This study aims to model the habitat suitability for the Sumatran elephant and identify factors that influence the distribution of Sumatran elephant. Habitat modeling was carried out using Maxent software, while the independent variables used were height, slope, temperature, distance from roads, distance from rivers, distance from plantations, distance from bushes, distance from open areas, distance from settlements, and cultivated forest land cover using RStudio software which produces class area, mean shape index, mean patch size, mean patch fractal dimension, and number of patches. Elephant presence data were derived from secondary GPS collar data within BBSNP. The modeling results reveal extensive areas of highly suitable habitat totaling 16,901.61 ha, with an additional 51,185.74 ha identified as suitable habitat. Factors influencing habitat suitability and the distribution of the Sumatran elephant population in BBSNP include elevation, forest cover, and distance from rivers.
Keyword: Habitat suitability, modeling, sumatran elephant, BBSNP

Judul: Spatial Distribution of Traces of Sumatran Elephant (Elephas maximus sumatranus Temminck, 1847) Activity in Pemerihan Resort Bukit Barisan Selatan National Park
Abstrak: Penurunan populasi gajah Sumatra mengindikasikan pentingnya kajian penelitian terkait jejak aktivitas gajah Sumatra. Penelitian ini bertujuan untuk mengidentifikasi jenis jejak aktivitas, menduga bentuk sebaran spasial jejak aktivitas, dan menganalisis hubungan jejak aktivitas dengan karakteristik habitat gajah Sumatra di Resort Pemerihan. Metode yang digunakan adalah pengamatan langsung pada jalur transek sepanjang 1 km dan studi literatur. Hasil penelitian menunjukkan bahwa jenis jejak aktivitas gajah Sumatra terdiri dari feses dan tapak. Jejak aktivitas yang paling banyak ditemukan adalah feses di hutan sekunder. Bentuk sebaran spasial jejak aktivitas gajah Sumatra adalah mengelompok dengan nilai IM=2,61. Sebaran spasial jejak aktivitas gajah Sumatra hubungan dengan karakteristik habitat yaitu tipe tutupan lahan (hutan sekunder), kelas topografi (datar), jarak dari sumber air (<1000 m), dan jarak dari permukiman (1000-2000 m). Pengelolaan habitat dan populasi gajah Sumatra melalui pengayaan pakan dan kegiatan penangkaran diperlukan sebagai bentuk upaya konservasi gajah Sumatra., The decline in the sumatran elephant population indicates the importance of research studies related to the traces of Sumatran elephant activities. This study aims to identify the types of activity traces, estimate the shape of the spatial distribution of activity traces, and analyze the relationship between activity traces and the characteristics of the Sumatran elephant habitat at Pemerihan Resort. The method used is direct observation on a 1 km transect line and literature study. The results showed that the types of traces of Sumatran elephant activity consisted of feces and footprints. The most traces of activity found were feces in secondary forest. The form of the spatial distribution of the Sumatran elephant's activity traces is clustered with a value of IM=2,61. The spatial distribution of Sumatran elephant activity traces is related to habitat characteristics, namely land cover type (secondary forest), topographic class (flat), distance from water sources (<1000 m), and distance from settlements (1000-2000 m). Management of the habitat and population of Sumatran elephants through enrichment of feed and captive activities is needed as a form of Sumatran elephant conservation efforts.
Keyword: activity traces, Pemerihan Resort, spatial distribution shape, Sumatran elephant

Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
Keyword: