Judul: Analysis of Extreme Rainfall in Indonesia During The Period of June-July-August from 1979-2021
Abstrak: Kejadian anomali ekstrem basah di Indonesia pada periode Juni-Juli-Agustus telah menjadi perhatian utama dalam penelitian meteorologi. Penelitian ini bertujuan untuk menganalisis kejadian anomali ekstrem basah di Indonesia pada periode Juni-Juli-Agustus tahun 1979-2021. Penelitian ini menunjukkan bahwa periode Juni-Juli-Agustus pada tahun 1979-2021 memiliki kejadian curah hujan ekstrem paling sedikit satu kejadian yaitu berjumlah 33 tahun yaitu 1979, 1980, 1981, 1983, 1984, 1985, 1986, 1988, 1989, 1990, 1992, 1993, 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2016, 2017, 2019, 2020 dan 2021. Terjadinya anomali ekstrem basah pada tahun-tahun tersebut tidak lepas dari oleh fenomena La Niña, IOD negatif dan La Niña Modoki. Pergeseran pita curah hujan terjadi pada tahun-tahun tertentu seperti pada tahun 1998 dan tahun-tahun lainnya. Suhu permukaan laut yang menghangat tercatat pada tahun-tahun tertentu seperti pada tahun-tahun tertentu. OLR menjelaskan kejadian curah hujan ekstrim pada tahun terjadi pada fenomena El Niño dan IOD Positif yaitu pada tahun-tahun tertentu. Mean sea level pada semua wilayah kejadian anomali curah hujan ekstrem menunjukan anomali negatif., The occurrence of extreme wet anomalies in Indonesia during the period of June-July-August has been a major concern in meteorological research. This study aims to analyze the occurrence of extreme wet anomalies in Indonesia during the period of June-July-August from 1979 to 2021. The study shows that the period of June-July-August from 1979 to 2021 had at least one extreme rainfall event, with a total of 33 years, namely 1979, 1980, 1981, 1983, 1984, 1985, 1986, 1988, 1989, 1990, 1992, 1993, 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2016, 2017, 2019, 2020 and 2021. The occurrence of extreme wet anomalies in those years was due to La Niña phenomenon, negative IOD and La Niña Modoki. Shifts in rainfall bands occurred in certain years such as in the year of 1998 and other years. The sea surface temperature has been recorded to be warm in certain years, such as in the years you mentioned. OLR explains that extreme rainfall events occur during El Niño and positive IOD phenomena, which happen in certain years. The mean sea level in all regions of extreme rainfall anomalies shows negative anomalies.
Keyword: Anomaly, Sea Surface Temperature, Zonal Wind, Meridional Wind, Precipitation

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 Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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