Judul: Diversity and Associations of Gastropods in the Mangrove Ecosystem of Lancang Island, Kepualauan Seribu, DKI Jakarta
Abstrak: Ekosistem mangrove merupakan area pada batas pasang surut dengan gradien sifat lingkungan yang tajam. Salah satu biota yang dapat hidup pada ekosistem ini adalah gastropoda. Penelitian ini bertujuan untuk mengetahui keanekaragaman dan hubungan asosiasi gastropoda dan mangrove yang ada di Pulau Lancang, Kepulauan Seribu, DKI Jakarta. Penelitian ini dilakukan menggunakan metode transek garis dan transek kuadran, serta pengukuran kualitas air dan fraksinasi sedimen di empat stasiun. Hasil penelitian menunjukkan bahwa kualitas perairan di Pulau Lancang tergolong baik dengan tipe substrat berpasir. Genus mangrove yang berhasil diidentifikasi adalah Rhizophora, Sonneratia, dan Avicennia. Gastropoda yang teridentifikasi terdiri dari 12 spesies, yang berasal dari 11 genus dan 9 famili. Spesies dengan jumlah terbanyak yaitu Terebralia palustris, Monodonta labio, dan Littoraria scabra. Hasil analisis koresponden menunjukkan bahwa terdapat dua pengelompokkan komunitas gastropoda dengan asosiasi tertinggi pada mangrove Rhizophora. Spesies gastropoda yang berasosiasi dengan Rhizophora adalah Littoraria scabra, Monodonta labio, Tectus pyramis, Nerita albicilla, Cerithidea cingulata, Terebralia palustris, dan Telescopium telescopium., Mangrove ecosystem is an area at the tidal boundary with a sharp gradient in environmental characteristics. One type of biota that can live in this ecosystem is gastropods. This research aimed to understand the diversity and association between gastropods and mangrove on Lancang Island, Kepulauan Seribu, DKI Jakarta. The study utilized line and quadrant transect methods, along with water quality and sediment fractination were measured at four stations. The research findings indicate that the water quality on Lancang Island is relatively good, with substrates dominated by sand. Mangrove genera identified were Rhizophora, Sonneratia, and Avicennia. Gastropods comprised of 12 species, originating from 11 genera and 9 families. The species with highest occurrence were Terebralia palustris, Monodonta labio, and Littoraria scabra. Correspondencce analysis results show that there are two groupings associated, with the highest gastropods composition associated with Rhizophora mangroves. Species associated with Rhizophora include Littoraria scabra, Monodonta labio, Tectus pyramis, Nerita albicila, Cerithidea cingulata, Terebralia palustris, and Telescopium telescopium.
Keyword: Association, Diversity, Gastropods, Mangrove ecosystem

Judul: Diversity and Association of Epifauna Gastropods in Mangrove and Seagrass of Tidung Kecil Island, Seribu Island
Abstrak: Pulau Tidung Kecil memiliki berbagai ekosistem pesisir, seperti ekosistem mangrove dan lamun. Kedua ekosistem tersebut menjadi tempat berlindung, mencari makan, dan memijah bagi gastropoda. Penelitian ini bertujuan menganalisis keanekaragaman dan asosiasi gastropoda epifauna pada mangrove dan lamun Pulau Tidung Kecil, Kepulauan Seribu. Pengamatan data mangrove, lamun, dan gastropoda dilakukan pada 4 (empat) stasiun dengan metode transek garis dan transek kuadrat, setiap stasiun dilakukan pengukuran kualitas perairan. Gastropoda epifauna yang ditemukan pada lokasi penelitian terdiri dari 25 spesies dan 11 famili yaitu famili Cerithiidae, Ellobiidae, Littorinidae, Muricidae, Nassariidae, Naticidae, Neritidae, Potamididae, Strombidae, Trochidae, dan Turbinidae dengan nilai keanekaragaman keseluruhan stasiun tergolong sedang. Spesies gastropoda epifauna yang mendominasi yaitu Terebralia palustris dari famili Potamididae. Spesies mangrove yang ditemukan pada lokasi penelitian yaitu Rhizophora stylosa, sedangkan spesies lamun yaitu Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, dan Halophila ovalis. Kualitas perairan pesisir Pulau Tidung Kecil tergolong baik untuk mangrove, lamun, dan gastropoda dengan tipe substrat lempung berdebu. Hasil analisis CA menunjukkan bahwa famili gastropoda Cerithiidae, Ellobiidae, Muricidae, Naticidae, Neritidae, Strombidae, dan Turbinidae berasosiasi dengan lamun, sedangkan famili gastropoda Littorinidae dan Trochidae berasosiasi dengan mangrove., Tidung Kecil Island has various coastal ecosystems, such as mangrove and seagrass ecosystems. Both ecosystems provide shelter, foraging, and spawning for gastropods. This study aims to analyze the diversity and association of epifauna gastropods in the mangrove and seagrass of Tidung Kecil Island, Seribu Island. Observation of mangrove, seagrass, and gastropod data was carried out at 4 (four) stations using line transect and quadratic transect methods, each station measuring water quality. The epifauna gastropods found at the study site consisted of 25 species and 11 families, namely Cerithiidae, Ellobiidae, Littorinidae, Muricidae, Nassariidae, Naticidae, Neritidae, Potamididae, Strombidae, Trochidae, and Turbinidae with the overall diversity value of the stations classified as moderate. The dominant epifauna gastropod species was Terebralia palustris from family Potamididae. The mangrove species found at the research site was Rhizophora stylosa, while the seagrass species were Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, and Halophila ovalis. The coastal water quality of Tidung Kecil Island was classified as good for mangroves, seagrasses, and gastropods with a silt loam type of substrate. The results of CA analysis showed that the gastropod families Cerithiidae, Ellobiidae, Muricidae, Naticidae, Neritidae, Strombidae, and Turbinidae were associated with seagrass, while the gastropod families Littorinidae and Trochidae were associated with mangrove.
Keyword: lamun, association, diversity, gastropod, mangrove, seagrass, asosiasi, gastropod, keanekaragaman

Judul: Pembuatan Film Tipis Cu2ZnSnS4 sebagai Lapisan Penyerap Cahaya pada Sel Surya Menggunakan Metode Elektrodeposisi
Abstrak: Thin film of Cu2ZnSnS4 (CZTS) is an alternative semiconductor used as light absorber layer on solar cell. CZTS can replace silicon that commonly used as commercial semiconductor. The advantage of using CZTS as absorber layer is due to the abundance of its chemical composer on earth, and its high value of absorption coefficient. The absorber layer was made by using electrodeposition method on ITO glass substrates. The films were deposited at room temperature using potentiostatic mode with a potential of –1.05 V for 30, 45, and 60 minutes. After that, the films were annealed at two different temperatures, 180 ºC and 500 °C, for 45 minutes in N2/H2S atmosphere. Based on X-ray diffraction analysis, the polycrystalline thin film obtained fall into kesterite crystal phase. This type of crystal was obtained when the CZTS was annealed at 500 °C in H2S/N2 atmosphere. The value of optical band gap energy for the CZTS thin film was 2.2 eV with the film thickness about 1.228–6.366 μm. The sample of CZTS with electrodeposition time of 45 minutes and annealing temperature of 500 °C showed the best result and in conformity with absorber layers criteria for solar cells.
Keyword: semiconductor, ITO glass, CZTS thin film, electrodeposition