Judul: Screening of Active Antibiofouling and Antibiocorrosion&#160;Compounds from Indonesian Marine Organisms Using NMR Spectroscopy&#160;Analysis
Abstrak: Industri maritim sebagai pendorong utama perdagangan global dan pertumbuhan ekonomi mengalami kerugian masif yang disebabkan oleh aktivitas biofouling dan biokorosi. Penelitian ini bertujuan menapis sejumlah 173 sampel lapisan EtOAc dan H2O organisme laut kategori toksisitas lemah hingga nontoksik terhadap serangkaian bioasai (antibakteri, antiquorum sensing, biosurfaktan, antibiofouling, dan antibiokorosi) dan analisis KLT serta NMR 1H. Sejumlah 15 dari total 173 sampel adalah aktif antibakteri terhadap Pseudomonas aeruginosa dan Staphylococcus aureus. Dari 15 sampel, 8 sampel berpotensi mengandung biosurfaktan. Di antara 8 sampel tersebut, 4 sampel adalah aktif sebagai inhibitor quorum sensing terhadap P. aeruginosa. Lapisan EtOAc tunikata (D1-I-0159-22E) memperlihatkan aktivitas terampuh terhadap asai antibiofouling (100 µg/mL, tidak ada kematian dan tidak ada pelekatan byssus) dan antibiokorosi (35 µg/mL, mpy 10,70±1,70). Analisis KLT dan NMR 1H menunjukkan keberadaan senyawa alkaloid dan terpenoid pada lapisan EtOAc tunikata, D1-I-0159-22E, As the primary driver of global trade and economic growth, the maritime industry is experiencing massive losses caused by biofouling and biocorrosion activities. This research aims to screen a total of 173 samples of EtOAc and H2O layers of marine organisms with weak to non-toxic categories against a series of bioassays (antibacterial, antiquorum sensing, biosurfactant, antibiofouling, and antibiocorrosion) and TLC as well as 1H NMR analyses. Among the 173 total samples evaluated, 15 showed antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus. Of the 15 samples, 8 potentially contained biosurfactant properties. Among these 8 samples, 4 were active as inhibitors of quorum sensing against P. aeruginosa. The EtOAc layer of tunicate (D1-I-0159-22E) exhibited the most potent activity in the antibiofouling (100 µg/mL, no death, and no byssus adhesion) and the antibiocorrosion (35 µg/mL, mpy 10.70±1.70) assays. TLC and 1H NMR analyses indicated the presence of alkaloid and terpenoid compounds in the EtOAc layer of tunicate, D1-I-0159-22E.
Keyword: NMR, antibiofouling, antibiokorosi, antiquorum sensing, biosurfaktan

Judul: Analisis Pemanfaatan Senyawa Terpenoid Sebagai Antifouling Agent untuk Menekan Pertumbuhan Teritip (Balanus sp.)
Abstrak: Teritip merupakan inveterbrata yang masuk ke dalam gologan crustacea dan termasuk ke dalam biota biofouling. Banyaknya penggunaan TBT dan tembaga sebagai bahan antifouling yang merupakan bahan yang berbahaya bagi lingkungan maka mendorong terciptanya bahan antifouling dari bahan alami yang ramah lingkungan. Penelitian ini bertujuan untuk menganalisis efek penambahan senyawa antifouling (Terpenoid) terhadap jumlah dan biomassa teritip yang menempel pada substrat yang di tenggelamkan di Pelabuhan Dermaga Muara Angke. Setiap subtrat yang di lapisi formula antifouling, menggunakan dosis yang berbeda. Penelitian ini menggunakan rancangan acak lengkap dengan empat perlakuan dan enam ulangan. Perlakuan pertama terdiri dari kontrol yang menggunakan cat tanpa campuran senyawa terpenoid dan tiga perlakuan lainnya yang menggunakan tambahan senyawa terpenoid dengan dosis masing-masing 40, 50, dan 60 ml. Hasil dari penelitian ini menunjukkan bahwa hasil terbaik yang di peroleh menggunakan formula dengan tambahan senyawa terpenoid sebanyak 60 ml yang menunjukkan jumlah dan bobot teritip yang paling rendah., Teritip is an inveterbrata that is included in the crustacean field and is included in the biofouling biota. The large number of uses of TBT and copper as anti-fouling materials which are harmful to the environment encourages the creation of anti-fouling materials from natural, environmentally friendly materials. This study aims to determine the effect of the addition of antifouling compounds (Terpenoids) on the amount and biomass of trite attached to the substrate submerged in Muara Angke Harbor. Each substrate is coated with an antifouling formula, using a different dosage. This study used a completely randomized design with four treatments and six replications. The first treatment consisted of control using paint without a mixture of terpenoid compounds and three other treatments that used additional terpenoid compounds with doses of 40, 50, and 60 ml, respectively. The results of this study indicate that the best results are obtained using a formula with the addition of 60 ml of terpenoid compounds, which shows the lowest number and weight of teritip
Keyword: Teritip, biofouling, antifouling, Terpenoid

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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