Judul: Kohabitasi Ruang Lutung Sentarum (Presbytis chrysomelas cruciger) di Kawasan Bukit Semujan Taman Nasional Danau Sentarum.
Abstrak: Lutung sentarum (Presbytis chrysomelas cruciger) termasuk dalam kategori Critically Endangered (CE) atau terancam punah. Tujuan dari penelitian ini yaitu untuk memetakan wilayah, mengetahui tumpang tindih, dan bentuk kohabitasi primata. Penelitian ini dilaksanakan pada bulan Januari 2022 dengan menggunakan metode ad libitum sampling dan scan sampling. Hasil dari penelitian ini diketahui luas wilayah jelajah lutung sentarum sebesar 25,2 ha dan monyet ekor panjang sebesar 7,0 ha. Tumpang tindih ruang kedua primata ini terjadi pada strata C. Nilai tumpang tindih dianalisis menggunakan Indeks Jaccard penggunaan ruang vertikal lutung sentarum dan monyet ekor panjang yaitu 0,13, sedangkan Indeks Jaccard terhadap jumlah jenis pakan sebesar 0,56. Nilai tumpang tindih kedua primata berdasarkan jenis pakan dengan perhitungan MacArthur dan Levin sebesar 0,82. Perhitungan luas relung ekologi menggunakan persamaan Smith untuk lutung sentarum pada taraf nyata (selang kepercayaan 95%) adalah FT =0,795 dengan nilai batas bawah dan batas atas sebesar 0,625 ≤ FT ≥ 0,918, monyet ekor panjang senilai FT = 0,664 dengan nilai batas bawah dan batas atas sebesar 0,846 ≤ FT ≥ 0,429. Kata kunci: Danau Sentarum, kohabitasi, Lutung sentarum, Monyet ekor panjang, Bornean Langur (Presbytis chrysomelas ssp. cruciger) is included in the Critically Endangered (CE) category or threatened with extinction. The purpose of this study was to map the area, find out the overlap, and the form of cohabitation of the primates. This research was conducted in January 2022 using ad libitum sampling and scan sampling methods. The results of this study indicated that the roaming area of the Bornean langur is 25,2 ha and the long-tailed monkey is 7,0 ha. The spatial overlap of these two primates occurs in strata C. The value of the overlap was analyzed using the Jaccard Index of using vertical space for langur sentarum and long-tailed monkeys, which is 0.13, while the Jaccard Index for the number of types of feed is 0.56. The overlapping value of the two primates based on the type of feed calculated by MacArthur and Levin was 0.82. Calculation of ecological niche area using Smith's equation for langur sentarum at a significant level (95% confidence interval) for langur sentarum is FT = 0.795 with the lower and upper limit values of 0.625≤ FT ≥ 0.918, long-tailed monkeys worth FT = 0.664 with the lower and upper limit values of 0.846 ≤ FT ≥0.429. Keywords: Bornean Langur, Cohabitation, Long tailed monkey, Sentarum Lake
Keyword: Kohabitasi, Danau Sentarum, Lutung Sentarum, Monyet Ekor Panjang

Judul: Analysis of habitat types of tricolour langur (Presbytis  chrysomelas ssp. cruciger, Thomas 1892) in Danau Sentarum National Park, Analysis of habitat types of tricolour langur (Presbytis  chrysomelas ssp. cruciger, Thomas 1892) in Danau Sentarum National Park
Abstrak: Lutung sentarum merupakan primata endemik Kalimantan yang saat ini berada pada status Critically Endangered (kritis) berdasarkan daftar merah IUCN dan belum dilindungi undang-undang. Penelitian ini bertujuan menganalisis tipe habitat lutung sentarum di kawasan Bukit Semujan dan mengkaji kelimpahan tumbuhan sumber pakan yang merupakan salah satu unsur daya dukung habitat. Hasil penelitian menunjukkan bahwa habitat lutung sentarum di kawasan Bukit Semujan terkategorikan ke dalam tiga tipe hutan, yaitu hutan rawa; peralihan; dan bukit. Terdapat 83 spesies dari 40 famili tumbuhan menyusun kawasan Bukit Semujan. Hutan rawa didominasi famili Myrtaceae, hutan peralihan didominasi Cluciaceae, dan hutan bukit didominasi oleh famili Dipterocarpaceae. Secara struktur, vegetasi penyusun habitat lutung memiliki permudaan yang melimpah sehingga menjadi indikasi bahwa habitat lutung mampu beregenerasi. Selain itu, sebanyak 16 jenis tumbuhan penyedia pakan lutung sentarum tersebar di seluruh tipe habitat dan dimungkinkan dijangkau oleh lutung karena kondisi tajuk antar habitat yang saling interkoneksi. Kata kunci: endemik, hutan rawa, IUCN, regenerasi, Tricolour langur is an endemic primate of Borneo which is currently in Critically Endangered based on the IUCN red list and not protected by government’s law. Aim of this research is to analyze the habitat type in the Bukit Semujan and assess the abundance of vegetation that provides food, which is one element of the carrying capacity of the habitat. The results showed that the tricolour langur habitat in the Bukit Semujan area was categorized into three types of forest based on topographic and edaphic differences, namely swamp forest; transition; and hills. There are 83 specieses from 40 plant families that make up the Bukit Semujan area. The swamp forest is dominated by the Myrtaceae, the transitional forest is dominated by the Cluciaceae, and the hill forest is dominated by the Dipterocarpaceae family. Structurally, the vegetation that makes up the lutung habitat has abundant regeneration so that it is an indication that the lutung habitat is able to regenerate. In addition, as many as 16 specieses of plants that provide food for tricolour lutung are spread across all types of habitats and it is possible for langurs to reach them due to the interconnection of canopy conditions between habitats. Keywords: endemic, IUCN, regeneration, swamp forest
Keyword: endemik, hutan rawa, IUCN, regenerasi

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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