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 Gastropods in the Seagrass Ecosystem on Tidung Kecil Island, Seribu Islands.
Abstrak: Gastropoda berperan dalam proses dekomposisi dan kestabilan ekosistem. Penelitian ini bertujuan menganalisis keanekaragaman dan asosiasi gastropoda pada ekosistem lamun Pulau Tidung Kecil, Kepulauan Seribu. Pengamatan menggunakan metode Seagrass Watch di empat stasiun ekosistem lamun. Tiap stasiun diukur parameter lingkungan perairan dan sedimen. Gastropoda yang ditemukan terdiri dari 53 spesies yang tergolong dalam 13 famili dengan kepadatan tertinggi di seluruh stasiun dimiliki oleh famili Cerithiidae yaitu 1503 ind/m2. Spesies dengan nilai kepadatan tertinggi adalah Cerithium punctatum di Stasiun 3 sebesar 303 ind/m2. Spesies lamun yang ditemukan yaitu Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, dan Halophila ovalis. Kualitas perairan di ekosistem lamun masih berada dalam baku mutu gastropoda dengan substrat didominasi pasir. Analisis korespondensi (CA) menunjukkan terdapat tiga kelompok utama asosiasi gastropoda dengan vegetasi lamun. Komposisi gastropoda pada lamun jenis T. hemprichii dan lamun campuran memiliki nilai tertinggi. Analisis korelasi Pearson menunjukkan kerapatan lamun dengan kepadatan gastropoda memiliki hubungan sangat kuat dan searah., Gastropods significantly contribute to ecosystem stability and decompositions. This study examines the diversity and association of gastropods in seagrass ecosystem of Tidung Kecil Island, Seribu Islands. Observations were conducted at four stations using the Seagrass Watch method, measuring aquatic and sedimentary parameters. Gastropods found consisted of 53 species from 13 families with the highest density throughout the stations is Cerithiidae of 1503 ind/m2. The species with the highest density value is Cerithium punctatum at Station 3 of 303 ind/m2. Seagrass species found were Thalassia hemprichii, Enhalus acoroides, Cymodocea rotundata, and Halophila ovalis. The water quality in the seagrass ecosystem aligns with the gastropod life standards with sand-dominated substrate. The results of correspondence analysis (CA) revealed three main groups of gastropod associations with seagrass vegetation. The composition of gastropods in T. hemprichii seagrass and mixed seagrass has the highest value. Pearson correlation showed that seagrass density and gastropod density have a very strong and proportional relationship.
Keyword: association, diversity, gastropods, seagrass

Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4