ANALYSIS OF CLASSIFICATION METHODS FOR MAPPING SHALLOW WATER HABITATS USING SPOT-7 SATELLITE IMAGERY IN NUSA LEMBONGAN ISLAND, BALI

Shallow water habitat maps are crucial for the sustainable management purposes of marine resources. The use of a better digital classification method can provide shallow water habitat maps with the best accuracy rate that is able to indicate actual conditions. Experts use the object-based classification method as an alternative to the pixel-based method. However, the pixel-based classification method continues to be relied upon by experts in obtaining benthic habitat conditions in shallow water. This study aims to analyze the classification results and examine the accuracy rate of shallow-water habitats distribution using SPOT-7 satellite imagery in Nusa Lembongan Island, Bali. Water column correction by Lyzenga 2006 was opted, while object-based and pixel-based classification was used in this study. The benthic habitat classification scheme uses four classes: substrate, seagrass, macroalgae, and coral. The results show different accuracy is obtained between pixel-based classification with maximum likelihood models and object-based classification with decision tree models. Mapping benthic habitats in Nusa Lembongan, Bali, with object-based classification and decision tree models, has higher accuracy than the other with 68%

ANALISA KONTAK CERAMIC-ON- CROSSLINKED UHMWPE PADA SAMBUNGAN TULANG PINGGUL BUATAN MENGGUNAKAN METODE ELEMEN HINGGA

Analisa kontak yang terjadi pada permukaan acetabular cups perlu terus dikembangkan dengan mengaplikasikan new material ceramic formulations sebagai femoral head dan crosslinked UHMWPE sebagai acetabular cup. Penelitian ini menggunakan metode elemen hingga dengan software bantu Abaqus. Tujuan penelitian ini adalah untuk mengetahui pengaruh penggunaan new material ceramic formulations sebagai femoral head dan highly crosslinked UHMWPE sebagai acetabular cup terhadap hasil distribusi tekanan kontak dan von Mises stress yang terjadi pada sistem sambungan tulang buatan jika diberi beban statik selama kurun waktu tertentu. Hasil yang didapat dari penelitian ini menunjukkan bahwa distribusi tekanan kontak yang terjadi pada ceramic-on-polyethylene akan berkurang dengan semakin besarnya angular koordinat. Perbedaan meterial femoral head tidak berpengaruh pada tekanan kontak yang terjadi baik pada saat awal pembebanan (t = 1 detik) maupun akhir pembebanan (t = 300 detik). Tekanan kontak maksimum yang terjadi pada tiap pasangan besarnya relatif sama satu dengan yang lain. Dari hasil pemodelan tersebut juga terlihat perbedaan besar von Mises stress dari ketiga pasangan tidak signifikan. Namun besar tekanan kontak dan von Mises stress yang terjadi mengalami perubahan terhadap waktu. Fenomena perubahan ini hanya terjadi pada bagian acetabular cup karena pada bagian ini material terbuat dari polyethylene yang bersifat viscoelastic. Kata kunci: Sambungan tulang pinggul buatan, crosslinked UHMWPE, ceramic, metode elemen hingg

Ecological Value of Soil Organic Matter (SOM) at Tropical Evergreen Aglaia-Streblus Forest of Meru Betiri National Park, East Java, Indonesia

As part of carbon pools, forest soil stores soil organic matter (SOM) that contains many elements including organic C, N, P, and K. These elements contribute nutrients for biogeochemical cycles within the ecosystem. This study was done to determine the ecological value of forest soil organic matter at tropical evergreen Aglaia-Streblus forest of Meru Betiri National Park (MBNP), East Java, Indonesia. The data were sampled along gradient topography in Pringtali tropical forest of TMBNP. Direct measurements of soil moisture, temperature, and pH were taken in the field. The soil samples were extracted from 6 points of soil solum using soil auger, and then oven-dried to get value of dry-weight. The elements content of organic C, N, P, and K were analyzed and estimated at the laboratory. The ecoval of SOM was appraised using developed ecological valuation tool. The result showed that SOM contributed higher ecoval of organic C (66.03 Mg ha-1) than other elements. Compared to P and K elements, N had the highest stock of element content. However, comparing to other two tropical forest ecosystems of Asia the ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features.The ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features. The ecovals contributed about 2.440,64 - 6.955,50 USD or  31.271.923,73 - 89.120.837,23  IDR per hectare of ecological value (d) to the ecosystem. This value was mainly contributed by organic C stock in the TMBNP forest SOM. It means the forest SOM had higher element content of organic C than N, P, and K elements. This d value is an indicator for TMBNP to protect the SOM elements meaning protecting their resources to sustain the biogeochemical cycles in the forest ecosystem. All the management and policy correlated to this protected area should consider this valuable information for their plan and actions

Pollen Viability and Pollen Tube Growth of IPB's Papaya

The purpose of the research was to examine the pollen germination process and growth rate of pollen tubes of papaya. Pollen tube growth of nine genotypes of papaya (IPB 1, IPB 2, IPB 3, IPB 4, IPB 5, IPB 7, IPB 8, IPB 9, and IPB 10) was investigated in this experiment in order to study their pollen germination rate and pollen viability. The fresh pollen were excised from the fl owers of papaya grown at Tajur Field Station of Research Center for Tropical Fruit, Bogor Agricultural University (IPB), Bogor. The extracted pollen was cultured aseptically on the Brewbaker and Kwack medium (pH 7.3) at ambient temperature of 26-28 °C. Pollen germination and pollen tube growth was observed under optical microscope with 100 and 400 magnifi cation. Papaya pollen viability was not associated with size-based categories of papaya fruits. IPB 4 had the longest pollen tube at fi rst 30 minutes after germination (115.5 µm), whereas IPB 10 had the shortest (99.5 µm). The distance from stigma to ovary in hermaphrodite fl owers varies with genotypes, ranging from 7.38 to 13.44 mm. Average length of pollen tube within four hours of germination for small papaya fruit category (IPB 1, IPB 3, and IPB 4) was 1,030.67 ± 19.14 μm, while the distance between stigma and ovary was short (14.85 ± 2.19 mm) so that the expected of fertilization process occurred sooner. At the end of the experiment (four hours after germination), IPB 1 genotype had the longest pollen tube (1,052 µm) while IPB 9 genotype (913 µm) had the shortest pollen tube. Genotype with the highest percentage of germination at the end experiment was IPB 2 (65.65%), whereas the lowest was IPB 7 (42.56%)