Judul: Identification of Cross-Equatorial Northerly Surge and Indian Ocean Dipole Phenomenon in Rain Events in West Part of Java
Abstrak: Aliran massa udara yang berasal dari Laut Cina Selatan (LCS) melewati equator dan merambah ke Laut Jawa dan Pulau Jawa bagian Barat dapat menyebabkan peningkatan curah hujan yang dilewatinya, aliran tersebut dapat disebut Cross Equatorial Northerly Surge (CENS). Fenomena CENS bukan satu-satunya penyebab peningkatan atau penurunan curah hujan di Pulau Jawa. Indian Ocean Dipole (IOD) juga dapat menyebabkan perubahan curah hujan di Pulau Jawa. Penelitian ini bertujuan untuk menganalisis pola curah hujan selama kejadian CENS, IOD, dan secara bersamaan. Data yang digunakan pada penelitian ini yaitu data curah hujan lima stasiun pengamatan serta data angin permukaan, Suhu Permukaan Laut (SPL), anomali SPL dan transport kelembaban. Hasil penelitian menunjukkan bahwa peningkatan pola curah hujan yang tinggi di empat stasiun pengamatan selama CENS pada tahun 2004-05, kecuali di Stasiun Geofisika Cemara Bandung. Sementara selama CENS dengan IOD negatif pada tahun 2004 05, peningkatan pola curah hujan terjadi di Stasiun Klimatologi Dramaga Bogor, Meteorologi Kemayoran, dan Meteorologi Kertajati. CENS dengan IOD positif pada tahun 2019 menyebabkan rendahnya curah hujan di lima stasiun pengamatan dibandingkan selama kejadian CENS dan CENS dengan IOD negatif. Meskipun demikian, peran signifikan CENS dalam membawa massa udara lembab dapat mengakibatkan hujan., The airflow originating from the South China Sea (LCS) crosses the equator and extends to the Java Sea and Western Java Island, potentially causing increased rainfall along its path. This flow is referred to as the Cross-Equatorial Northerly Surge (CENS). However, the CENS phenomenon is not the sole factor influencing rainfall variability on Java Island. The Indian Ocean Dipole (IOD) also contributes to changes in rainfall patterns on Java. This study aims to analyze rainfall patterns during occurrences of CENS, IOD, and their combined effects. The data used in this research includes rainfall data from five observation stations, as well as surface wind data, Sea Surface Temperature (SST), SST anomalies, and moisture transport. The results show significant increases in rainfall patterns at four observation stations during CENS in 2004-05, except at the Geophysics Station Cemara Bandung. Meanwhile, during CENS with negative IOD in 2004-05, increased rainfall patterns were observed at the Climatology Station Dramaga Bogor, Meteorology Kemayoran, and Meteorology Kertajati. CENS with positive IOD in 2019 resulted in lower rainfall across the five observation stations compared to the periods of CENS and CENS with negative IOD. Nevertheless, the significant role of CENS in transporting moist air can lead to rainfall.
Keyword: CENS, IOD, Moisture Transport, Rainfall, SST

Judul: The Influence of the ﻿Super Indian Ocean Dipole ﻿(IOD) on Indonesia's Rainfall Anomaly in 2019
Abstrak: Indian Ocean Dipole (IOD) merupakan fenomena interaksi lautan dan atmosfer yang terjadi di kawasan Samudera Hindia. IOD memiliki keterkaitan dengan variasi iklim Indonesia, terutama variabilitas curah hujan. IOD cenderung terjadi bersamaan dengan El-Nino Southern Oscilation (ENSO), Namun hasil penelitian lainnya menemukan bahwa IOD dapat terjadi tanpa diiringi oleh ENSO. Salah satu IOD yang tidak diiringi ENSO adalah IOD (+) 2019. IOD juga memiliki keterkaitan dengan zona konvergensi (ITCZ). Penelitian bertujuan untuk mempelajari kondisi curah hujan Indonesia saat terjadinya IOD (+) 2019 serta keterkaitannya dengan sirkulasi atmosfer dengan menganalisis data-data curah hujan dan atmosfer. Penelitian ini meliputi tahapan analisis klimatologis curah hujan Indonesia, penentuan indeks IOD, analisis korelasi indeks IOD dengan curah hujan Indonesia, analisis anomali curah hujan dan suhu permukaan laut Indonesia tahun 2019, serta analisis klimatologis dan anomali zona konvergensi wilayah Indonesia tahun 2019. Hasil penelitian menunjukan bahwa IOD (+) 2019 menyebabkan penurunan curah hujan Indonesia, terutama saat memasuki periode bulan kering (Juli-September). IOD (+) 2019 juga menyebabkan terjadinya kontraksi/penyusutan ITCZ, sehingga menyebabkan terjadi penurunan curah hujan, terutama di Indonesia bagian Barat., Indian Ocean Dipole (IOD) is a phenomenon of ocean and atmosphere interaction that occurs in the Indian Ocean region. IOD has a relationship with Indonesia's climate variations, especially rainfall variability. IOD tends to occur simultaneously with the El-Nino Southern Oscilation (ENSO), but other studies have found that IOD can occur without ENSO. One of the IODs that is not accompanied by ENSO is IOD (+) 2019. IOD also has a relationship with the convergence zone (ITCZ). This study aims to study the conditions of rainfall in Indonesia during the IOD (+) 2019 and its relationship to atmospheric circulation by analyzing rainfall and atmospheric data. This research includes the stages of climatological analysis of Indonesian rainfall, determination of the IOD index, correlation analysis of the IOD index with Indonesian rainfall, anomaly analysis of rainfall and sea surface temperature in Indonesia in 2019, as well as climatological analysis and anomaly of the convergence zone of the Indonesian region in 2019. The results show that IOD (+) 2019 causes a decrease in Indonesia's rainfall, especially when entering the dry month period (July-September). IOD (+) 2019 also caused a contraction/shrinkage of the ITCZ, causing a decrease in rainfall, especially in western Indonesia.
Keyword: IOD, rainfall, atmospheric circulation, convergence zone

Judul: Synthesis of Chicken Eggshells-Based β-Tricalcium Phosphate Bioceramics and Their Biocompatibility Test as A Tooth Filler
Abstrak: Preservation of alveolar bone following tooth extraction is an important step in dental practices before dental implant placement. This study reported synthesis of β-Tricalcium Phosphate (β-TCP) bioceramics and its biocompatibility test as a tooth filler to maintain the desired alveolar ridge dimension and stimulate the bone healing processes in the area of tooth loss. β-TCP bioceramics was resulted directly from precipitation of calcinated chicken eggshells as calcium source and phosphoric acid. The corresponding β-TCP was mixed with chitosan 2% to get β-TCP pellet for biocompatibility testing. Biocompatibility testing of β-TCP on lower incisor was performed in rabbits and sheep as animal model. In this study, the x-ray diffraction (XRD) profiles showed that 1000 oC calcinated chicken eggshells correspond to calcium oxide (CaO). There was also transformation phase of CaO into Ca(OH)2 observed after more than three months stored. The XRD profiles proved that obtained β-TCP bioceramics by precipitation has the same pattern with that of reference data base and commercial β-TCP. Fourier transform infrared (FTIR) spectra were completely consistent with the result of crystallization processes observed by XRD measurements. Moreover, the purity of the product shown by the atomic absorption spectroscopy (AAS) resulted in Ca/P ratio of 1.48 which was closed to that of standard β-TCP ceramics. The repeatable XRD peaks patterns and FTIR spectra obviously showed the sample reproducibility. Sheep’s alveolar socket that is filled with the corresponding β-TCP demonstrated the expected results. The x-ray radiograph of sheep’s jaw indicated no change on mesio-distal of the edentulous area. Moreover, the histological results were completely consistent with the x-ray radiograph and macroscopic result which is proved by the formation of new bone. In the contrary with sheep’s result, histological results showed no tooth growth on rabbit proved by the presence of lipid and collagen on the extraction site. This result did not correspond to the x-ray radiograph and macroscopic results that demonstrated the tooth growth and erupted tooth. It is clear that the corresponding β-TCP could minimize the bone loss and maintain the dimension of alveolar ridge.
Keyword: β-tricalcium phosphate, chicken eggshells, rabbit, sheep, tooth filler