Judul: The sea surface salinity monsoonal and interannual variability; their implications on the catch rate of small pelagic fish, Java Sea
Abstrak: The monthly average of sea surface salinity (January 1994–December 2010 with a spatial resolution of 1o x1o) from Estimating Circulation and Climater of Ocean (ECCO) Dataset is used as a primary data, Dataset of wind (European Center For Medium Range Forecast, ECMWF) as a secondary parameter (monthly averages both for east-west (zonal) component and north-south (meridional) component, it is derived from 10 meters above sea level within period of January 1994–December 2010, with a spatial resolution of 2.5o x 2.5o) in this study. Time series analysis is conducted to obstain a complete picture of the Sea Surface Salinity (SSS) seasonal fluctuations. Results showed that SSS in the Java Sea has seasonal variability, which is shown by appearences of two SSS maximum and two SSS minimum annually. Based on monthly average in the northern part of Java Seas, the SSS is having range of 32 and 34,4 psu. In the first transitional season (March-April-May), SSS is relatively lower than the other season, i.e. NW monsoon, SE monsoon. The second transitional season (September-October-November), where it is found a low core SSS consentrated in the western part of the Java Sea and also in the south of Makassar strait. Results of the analysis shows that the catch varies according to temporal (monthly, seasonal, and annual), and to spatial in the Java Sea during the period 1990 to 1995. In the Java Sea, there are seven fishing ground of small pelagic fish, namely in the waters of north Pekalongan-Tegal, Java Karimun Islands, Bawean Island, Masalembo-Masalima Island, Matasiri Island, the southern Makassar Strait, and on the Kangean Island. Based on the total catch from the of seven regions, the average monthly percentage of the catch of round scads (Decapterus spp.), mackerels (Rastrelliger kanagurta), flat sardinella (Sardinella spp), round sardinella (Sardinella lemuru), bigeye scads (Selar crumenophthalmus), and yellowstripe scads (Selaroides leptolepis) are 48.50%, 16.97%, 14,15%, 10.80%, 8.65% and 0.93% respectively.
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Judul: Variability of Chlorophyll-a Concentration and Sea Surface Temperature in the Western Java Sea Using MODIS Satellite Data on Fish Catches
Abstrak: Konsentrasi klorofil-a (Chl-a) dan Suhu Permukaan Laut (SPL) adalah parameter penting yang berpengaruh terhadap keberadaan sumberdaya ikan. Tujuan penelitian ini adalah menganalisis variabilitas konsentrasi klorofil-a dan SPL dari satelit Moderate Resolution Maging Spectroradiometer (MODIS), serta hasil tangkapan ikan di Perairan Laut Jawa bagian barat. Selain itu data pendukung lainnya berupa El Nino Southern Oscillation (ENSO) bulanan dan Indeks Dipole Mode (DMI) bulanan juga digunakan dalam peneltiian ini. Penelitian ini dilaksanakan pada bulan Desember 2021-Juli 2022 di Perairan Laut Jawa bagian barat. Data SPL dan klorofil-a dianalisis berdasarkan data rata-rata bulanan dari hasil estimasi satelitMODIS selama 12 tahun (Januari 2010-Desember 2021). Hasil penelitian menunjukkan nilai konsentrasi klorofil-a berada dikisaran 0.42 mg/m³–1.55 mg/m³ yang mengalami peningkatan pada musim barat dan timur serta mengalami penurunan pada musim peralihan 1 dan 2. Nilai SPL berada dikisaran 29.05°C-30.71°C dan mengalami peningkatan saat musim peralihan 1 dan 2 yang dipengaruhi oleh peningkatan intensitas radiasi matahari dan pergerakkan massa air dari Timur Laut menuju Barat Daya. Variabilitas SPL dan klorofil-a memiliki kecenderungan terhadap hasil tangkapan ikan tembang di Perairan Laut Jawa bagian barat dan sekitarnya. Pada saat fenomena La Nina (ENSO Indeks positif) dan Dipole Mode Index bernilai negatif terjadi secara bersamaan, nilai klorofil-a relatif lebih tinggi dari normalnya dan nilai SPL relatif lebih rendah dari normalnya., Concentration of chlorophyll-a (Chl-a) and sea surface temperature (SST) are important parameters that affect the existence of fish resources. The purpose of this study was to analyze the variability of chlorophyll-a concentrations and SST from the Moderate Resolution Maging Spectroradiometer (MODIS) satellite, as well as fish catches in the western Java Sea. In addition, other supporting data in the form of monthly El Nino Southern Oscillation (ENSO) and monthly Dipole Mode Index (DMI) are also used in this study. This research was carried out in December 2021-July 2022 in the western part of the Java Sea. SST and chlorophyll-a data were analyzed based on monthly average data from the estimation results of the MODIS satellite for 12 years (January 2010-December 2021). The results showed that the concentration of chlorophyll-a was in the range of 0.42 mg/m³–1.55 mg/m³ which increased in the west and east monsoons and decreased in transition seasons 1 and 2. SST values were in the range of 29.05°C-30.71°C and experienced increase during transitional seasons 1 and 2 which are influenced by increased intensity of solar radiation and movement of water masses from the Northeast to the Southwest. The variability of SST and chlorophyll-a has a tendency to catch tembang fish in the western Java Sea and its surroundings. When the La Nina phenomenon (positive ENSO Index) and negative Dipole Mode Index occur simultaneously, the chlorophyll-a value is relatively higher than normal and the SST value is relatively lower than normal.
Keyword: Klorofil-a, Musim, Suhu Permukaan Laut, Chlorophyll-a, Season, Sea Surface Temperature

Judul: Katalis Zink Ferit Tersubstitusi Cu untuk Oksidasi Benzil Alkohol
Abstrak: Katalis berperan dalam menurunkan energi aktivasi. Katalis ZnFe2O4 dan ZnFe2O4 tersubstitusi Cu disintesis menggunakan metode kopresipitasi untuk digunakan dalam oksidasi benzil alkohol. Katalis dicirikan dengan spektrofotometer inframerah (FTIR) dan difraktometer sinar-X. Spektrum FTIR menunjukkan puncak serapan dari ikatan Zn-O dan Fe-O masing-masing pada rentang 559‒575 cm-1 dan 419‒447 cm-1. Difraktogram menunjukkan terbentuknya fase tunggal Zn0.6Cu0.4Fe2O4 pada katalis ZnFe2O4 tersubstitusi Cu 20%. Benzil alkohol dioksidasi dengan sistem refluks. Konversi benzil alkohol meningkat dengan meningkatnya suhu. Kadar benzaldehida yang dihasilkan dengan katalis ZnFe2O4 tersubstitusi Cu 20% lebih tinggi dibandingkan dengan katalis ZnFe2O4 yang tidak tersubstitusi dan yang tersubstitusi Cu 60 dan 80%. Hal tersebut menunjukkan bahwa katalis ZnFe2O4 tersubstitusi Cu 20% memiliki kinerja yang lebih baik dalam oksidasi benzil alkohol menjadi benzaldehida dengan kadar benzaldehida 8.763%.
Keyword: Benzil alkohol, katalis, oksidasi, ZnFe2O4