Judul: Analysis of 144 Years of Rainfall and Air Temperature Conditions and their Association with Climate Variability in Central Jakarta
Abstrak: Penelitian ini bertujuan mengidentifikasi perubahan tren suhu udara dan pola curah hujan, serta mengkaji pengaruh variabilitas iklim terhadap fluktuasi curah hujan dan suhu udara di wilayah Jakarta Pusat selama 144 tahun (1876-2019). Data ini dianalisis menggunakan metode analisis tren, analisis distribusi probabilitas, analisis spektral, dan korelasi curah hujan dan suhu udara dengan indeks El-Nino Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), dan Pacific Decadal Oscillation (PDO). Curah hujan, suhu minimum, suhu rata-rata, dan suhu maksimum mengalami kenaikan dengan laju kenaikan masing-masing sebesar 1,7747 mm/tahun, 0,0161oC/tahun atau 2,4oC, 0,0179oC/tahun atau 2,6oC, dan 0,0208oC/tahun atau 3,0oC selama 144 tahun. Analisis spektral menunjukkan bahwa variabilitas tertinggi curah hujan musim panas berada pada periode 17 bulan, sedangkan musim dingin berada pada periode 22 bulan. Suhu rata-rata dan suhu maksimum musim panas variabilitas tertinggi berada pada periode 83 bulan, sedangkan musim dingin, pada periode 31 bulan dan 83 bulan. ENSO dan curah hujan berkorelasi positif, sedangkan ENSO dan suhu udara berkorelasi negatif. IOD dan curah hujan berkorelasi positif hanya pada musim dingin, sedangkan IOD dengan suhu udara berkorelasi positif pada setiap musim. PDO tidak memiliki hubungan signifikan dengan curah hujan dan suhu udara hampir pada setiap musimnya. Penelitian ini menunjukkan bahwa terjadi peningkatan tren curah hujan dan suhu udara selama 144 tahun (1876-2019)., This study aims to identify changes in air temperature trends and rainfall patterns, and to examine the influence of climate variability on fluctuations in rainfall and air temperature in the Central Jakarta area for 144 years (1876-2019). This data was analyzed using the methods of trend analysis, probability distribution analysis, spectral analysis, and correlation in rainfall and air temperature with the El-Nino Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), and Pacific Decadal Oscillation (PDO) indices. Rainfall, minimum temperature, average temperature, and maximum temperature increased with an increased rate of 1,7747 mm/year, 0,0161oC/year or 2,4oC, 0,0179oC/year or 2,6oC, and 0,0208oC/year or 3,0oC over 144 years, respectively. Spectral analysis shows that the highest variability of summer rainfall is in the 17 months period, while winter is in the 22 months period. The highest variability of summer mean and maximum temperatures are in the 83 months, while the winter is in the 31-month and 83-month periods. ENSO and rainfall are positively correlated, while ENSO and air temperature are negatively correlated. IOD and rainfall are positively correlated only in winter, while IOD and air temperature are positively correlated every season. PDO has no significant relationship with rainfall and air temperature almost every season. This study shows an increasing precipitation and air temperature trend over 144 years (1876-2019).
Keyword: Air Temperature, ENSO, IOD, PDO, Rainfall

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: 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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