Judul: Variation of Weekly Home Range Characteristics  of Sumatran Elephants (Elephas maximus sumatranus) in Bentang Seblat
Abstrak: Bentang Seblat merupakan salah satu wilayah konflik gajah sumatra dengan manusia yang timbul karena permasalahan penggunaan ruang. Gajah sumatra memiliki preferensi tertentu terhadap karakteristik habitat dan berpengaruh terhadap pergerakan dan wilayah jelajahnya. Penelitian ini bertujuan untuk mengidentifikasi karakteristik wilayah jelajah mingguan dan menganalisis hubungan antara wilayah jelajah mingguan dengan karakteristik habitat gajah sumatra di bentang Seblat. Data GPS Collar pada November 2020 hingga Agustus 2022 diperoleh dari Balai Konservasi Sumber Daya Alam Provinsi Bengkulu Lampung dan karakteristik habitat diperoleh dari citra landsat 8. Data yang diperoleh dianalisis menggunakan uji chi-square dan analisis regresi berganda (MRA) dengan lima peubah yaitu tutupan lahan, kelerengan, jarak dari sumber air, jalan, dan pemukiman. Hasil penelitian menunjukkan bahwa wilayah jelajah mingguan bernilai 2,67 ha–239,98 ha dengan nilai rata-rata 46,1 ha. Persentase tertinggi dari masing masing karakteristik habitat meliputi hutan sekunder (55,38%), kelerengan datar1 (59,01%), jarak 0-450 m dari sumber air (35,11%), jarak 0-400 m dari jalan (70,81%), dan jarak 6-8 km dari pemukiman (50,37%). Luas wilayah jelajah mingguan sangat berhubungan dengan seluruh karakteristik habitat dengan tingkat signifikansi hubungan tertinggi adalah kelerengan datar dan jarak dari pemukiman., Bentang Seblat is one of the areas of conflict between Sumatran elephants and humans arising from space use problems because sumatran elephants have specific preferences for habitat characteristics. This study aims to identify the characteristics of the weekly home range and analyze the relationship of weekly home range with habitat characteristics of Sumatran elephants in bentang Seblat. GPS collar data on November 2020 until August 2022 was obtained from the Natural Resources Conservation Agency of Bengkulu-Lampung Province and habitat characteristics were obtained from landsat 8 imagery. The data obtained were analyzed using chi-square test and multiple regression analysis (MRA) with five variables: land cover, slope, distance from water sources, roads, and settlements. The results showed that the weekly home range was worth 2,67 ha – 239,98 ha, averaging 46,1 ha. The highest percentage of each habitat characteristic includes secondary forest (55,38%), flat slopes (59,01%), distances of 0-450 m from water sources (35,11%), distances of 0-400 m from roads (70,81%), and distances of 6-8 km from settlements (50,37%). The weekly home range is closely related to all habitat characteristics with the highest level of relationship significance is flat slope and distance from settlement.
Keyword: bentang Seblat, habitat, sumatran elephant, variation, weekly home range

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: Hydrothermal Synthesis of Biphasic Calcium Posphate
Abstrak: Biphasio calsium phosphate (BCP), which was a mixture of hydroxypatite (HA) and tricalcium phosphate (TCP), was synthesized by hydrothermal method followed by sintering process. Hydroxyapatite was produced by using natural calcium source CaO from hen's eggshell and (NH4)2HPO4 as phosphate souce, other hydroxyapatite sample was produce by using synthetic calcium source Ca(OH) and H3PO4 as phosphate source.
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