Judul: Stem Characteristics of Kenaf (Hibiscus cannabinus L.) Hydrothermal Carbonized
Abstrak: Karbonisasi merupakan suatu proses untuk mendapatkan produk arang dengan suhu tertentu umumnya menggunakan suhu rendah dibawah 400 ℃ untuk menghasilkan arang hidro dan suhu tinggi sekitar 600 ℃ untuk menghasilkan arang aktif. Tujuan penelitian ini adalah menganalisis pengaruh suhu dan waktu dari proses karbonisasi hidrotermal terhadap batang kenaf serta menghilangkan hemiselulosa pada batang kenaf dengan proses hidrotermal. Penelitian ini menggunakan proses karbonisasi hidrotermal pada batang kenaf dengan suhu 130 ℃, 150 ℃, 170 ℃ dengan waktu 3 jam, 4 jam, dan 5 jam. Hasil penelitian ini menunjukkan karbon terikat, daya jerap polutan, dan daya jerap iodin arang hidro batang kenaf meningkat seiring kenaikan suhu dan waktu dibandingkan kontrol batang kenaf. Arang hidro batang kenaf terbaik didapat pada suhu 170 ℃ dalam waktu 3 jam dikarenakan total daya jerap iodin yang paling tinggi. Karbonisasi hidrotermal terbukti mampu mengurangi kandungan hemiselulosa., Carbonization is a process to get charcoal products with a certain temperature generally using low temperatures below 400 ℃ to produce hydro charcoal and high temperatures around 600 ℃ to produce activated charcoal. The objective of this study was to analyze the effect of temperature and time from the hydrothermal carbonization process on kenaf stems and to remove hemicellulose from kenaf stems using a hydrothermal process. This study used a hydrothermal carbonization process on kenaf stems with temperatures of 130 ℃, 150 ℃, 170 ℃ with 3 hours, 4 hours, and 5 hours. The results of this study showed that the bound carbon, pollutant adsorption capacity, and iodine adsorption capacity of hydro charcoal kenaf stems increased with increasing temperature and time compared to control kenaf stems. The best kenaf stems hydro charcoal was obtained at a temperature of 170 ℃ within 3 hours due to the highest total iodine adsorption capacity. Hydrothermal carbonization is proven to be able to reduce the hemicellulose content.
Keyword: Arang hidro, batang kenaf, daya jerap, karbonisasi hidrotermal, Adsorption capacity, hydro charcoal, hydrothermal carbonization, kenaf stems

Judul: Characteristics of Pyrolysis Charcoal from Kenaf (Hibiscus cannabinus L.) Stem with Pyrolysis Carbonization
Abstrak: Karbonisasi pirolisis dipilih dalam penelitian ini karena metode ini memiliki kelebihan, yaitu tidak diperlukannya bahan tambah pada saat proses karbonisasi. Karbonisasi pirolisis menghasilkan produk berupa arang pirolisis. Limbah batang kenaf yang cukup banyak dan belum dimanfaatkan dengan optimal, mendasari penggunaan batang kenaf pada penelitian ini. Penelitian ini bertujuan untuk mengetahui pengaruh karbonisasi terhadap karakteristik arang pirolisis batang kenaf, serta mengetahui suhu dan waktu yang terbaik dalam melakukan karbonisasi pirolisis. Pada penelitian ini karbonisasi dilakukan dengan variasi suhu 175 °C, 200 °C, dan 225 °C dengan waktu karbonisasi 3, 4, dan 5 jam. Karakteristik yang diuji meliputi komponen kimia bahan, analisis proksimat arang hasil karbonisasi, daya jerap polutan, dan daya jerap iodin. Hasil pada penelitian ini menunjukkan bahwa, daya jerap polutan dan daya jerap iodin dari arang batang kenaf menjerap dengan baik dibandingkan dengan daya jerap batang kenaf sebelum dijadikan arang. Berdasarkan hasil pengujian daya jerap polutan dan total bilangan iodin, didapatkan arang terbaik pada suhu 225 °C selama suhu 4 jam., Pyrolysis carbonization was chosen in this study because this method has an advantage that it does not require additional materials during the carbonization process. Pyrolysis carbonization produces a product in the form of pyrolysis charcoal. There is a lot of kenaf stems and it has not been used optimally, underlies the use of kenaf stems in this study. This study aims to determine the effect of carbonization on the characteristics of pyrolysis charcoal from kenaf stems, as well as to determine the best temperature and time to carry out pyrolysis carbonization. In this study, carbonization was carried out with variations in temperature of 175 °C, 200 °C, and 225 °C with carbonization times of 3, 4, and 5 hours. The characteristics tested include the chemical components of the material, proximate analysis of carbonized charcoal, pollutant adsorption capacity, and iodine adsorption capacity. The results of this study indicate that the adsorption capacity of the pollutant and the iodine adsorption capacity of the kenaf stem charcoal is better than the adsorption capacity of the kenaf stem before being made into charcoal. Result showed that pollutant adsorption test and the total number of iodine, the best charcoal was obtained at a temperature of 225 °C for 4 hours.
Keyword: Arang pirolisis, batang kenaf, daya jerap iodin, daya jerap polutan, pirolisis, Charcoal pyrolysis, iodine number, kenaf stem, pollutants adsorbtion, pyrolysis

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: