Judul: Processing data radar cuaca C-Band Doppler untuk curah hujan: studi kasus Jabodetabek
Abstrak: Rainfall is one of the most important element of the weather in a region. The study of rainfall has be done with a lot of method. One of them is by using the weather radar. The weather radar is classifeid in many group according to its frequency. This radar using the Doppler Concept in its process. This research is indicated to learn the processing of weather radar C-Band Doppler including its software to get the rainfall data in Jabodetabek region and to see the movement of rain fall region with weather radar data. The processing of this radar is in the computer with Linux Operating System with many software must be included, C, Fortran, Perl, and NetCDF. The processing needs some of script which can turn the primary data which is RAW format into the rain fall data (mm/hr). Cressman modification was used in the process, in order to turn the Raw format into reflectivity. The process needs the equivalence of Marshall-Palmer, in order to turn the reflectivity into CAPPI data format and Image CAPPI format. The result of this process is in text format, which is contain longitude, altitude, height, and rain fall. This rainfall value will be able to create many weather and climate infomation, such as rain fall region, floods, and more. In this research, the aplication of rainfall data is limited into the condition of rainfall region. The rain fall data will show the movement of the rain fall in a region. Jakarta, Bogor, Depok, Tangerang, and Bekasi were area case of study. According to result, the maximum of rainfall region is happening in the east and south of Jabodetabek, one of them is Bogor. Results data also showed the decrease in altitude, precipitation will be smaller.
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Judul: Perbandingan Metode Koreksi Data Radar Cuaca Dengan Penakar Hujan Wilayah Bengkulu
Abstrak: Weather radar data can provide spatio temporal rainfall forecast at high- resolution. Radar covers a large area and captures the spatial variability of rainfall that increases a short-term predictability of rain. However, the rainfall derived from radar is inherently an estimated value that may contain bias. Also, the estimated value is derived indirectly from the radar reflectivity equation. Therefore, adjusting the estimated rainfall value based on the local observed rain gauge remains a research challenge. This study employed Bengkulu weather radar data and combined with the rainfall from automatic weather station at the Bengkulu Climatology Station. Observed rainfall datasets from 34 rain gauges over Bengkulu for 2015 to 2020 were used for the analysis, we selected December-February as representative of wet season, whereas June-August was for the dry season. Correction of radar data with rain gauge is calculated using the Mean Field Bias (MFB), Local Bias Correction (LBC), and Quantile Mapping (QM) approaches. MFB is a method for estimating the overall bias (average) for radar in a large domain. The LBC correction is a correction by considering the distance factor of the rain gauge to the radar location. Correction of bias QM corrects the data distribution using the probability approach. The Conversion of reflectivity to intensity using three different Z-R relationship, namely Marshall Palmer, Rosenfeld, and the new Z-R equation refers to previous research on the island of Sumatra. The results of analyses in the present study strongly indicated an improvement in radar data quality after the correction method was applied. The Local Bias Correction (LBC) method gives the best results compared to the MFB and QM methods for the Bengkulu region, with the highest correlation of 0.51. The best Z-R relationship is obtained from the Marshall Palmer equation. Bias correction performance in the wet season (DJF) has better results than in the dry season (JJA).
Keyword: Reflectivity, radar, correction, rain, method

Judul: Lignin Terlarut Asam dan Rasio Siringil-Guaiasil Lignin Pada Enam Jenis Kayu Eukaliptus
Abstrak: Lignin merupakan salah satu komponen kimia penyusun kayu selain dari selulosa, hemiselulosa dan ekstraktif. Sifat kimia lignin yang penting untuk diketahui diantaranya adalah kadar lignin dan reaktivitasnya. Pada penentuan kadar lignin dengan metode Klason, bisa diperoleh informasi kadar lignin Klason (lignin tidak larut asam) dan lignin terlarut asam. Sifat reaktivitas lignin dinyatakan dalam rasio siringil-guaiasil (rasio S/G) yang merupakan komposisi penyusun lignin. Berdasarkan penelitian terdahulu, lignin terlarut asam berkorelasi positif dengan kandungan metoksil. Sementara itu, kandungan metoksil juga berkorelasi positif dengan rasio siringil-guaiasil. Berdasarkan hal tersebut, proporsi siringil guaiasil diduga merupakan faktor penting dalam pembentukan lignin terlarut asam. Penelitian ini bertujuan untuk menentukan kadar lignin terlarut asam dan rasio siringil-guaiasil enam jenis kayu Eukaliptus dan korelasi antara keduanya, serta kemungkinan implikasinya terhadap sifat kayu, pengolahan dan penggunaannya sebagai bahan baku pulp. Penentuan kandungan lignin terlarut asam diukur dari filtrat penentuan lignin Klason. Lignin Klason merupakan fraksi padatan setelah penyaringan sedangkan lignin terlarut asam ditentukan dengan pengukuran penyerapan UV dari filtrat pada panjang gelombang 205 nm menggunakan koefisien absorpsi 110 lg-1 cm-1. Pengujian rasio siringil dan guaiasil penyusun molekul lignin dilakukan dengan metode Alkaline Nitrobenzene Oxidation seperti yang dilakukan oleh Chen (1992). Rasio siringil terhadap guaiasil dinyatakan sebagai perbandingan antara (siringaldehida+siringic acid)/(vanilin+vanilic acid). Hasil penelitian menunjukkan kadar lignin beragam antar jenis kayu yang berbeda dalam satu genus kayu Eukaliptus. Terdapat kecenderungan kadar lignin Klason yang lebih rendah diikuti oleh kadar lignin terlarut asam yang lebih tinggi. Lignin terlarut asam mempunyai korelasi yang kuat dengan rasio siringil-guaiasil. Lignin terlarut asam yang tinggi diperoleh dari lignin kayu yang memiliki rasio siringil guaiasil yang tinggi pula. Hubungan antara lignin terlarut asam dan rasio siringil-guaiasil dapat menjadi parameter penduga kemudahan suatu jenis kayu untuk didelignifikasi selama proses pulping.
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