Judul: Karbonisasi Nano Serat Selulosa Asetat dari Kapas yang Dibuat Dengan Metode Electrospinning
Abstrak: Cellulose content of cotton is 94%. The high value cellulose content of cotton makes the extraction cellulose in cotton will be easier. One method to making nano fiber that is electrospinning technique. Electrospinning method can produce nano fibers at a flow rate 1 ml/h, but at flow rate 1.75 ml/h and 2.5 ml/h produce nano spheres based on images of SEM. After carbonized of sample graphite formed, based on XRD data visible from the highest peak in the 2θ is 26.2o which is the typical peak of Graphite Carbon based on the data pattern JCPDS No. 41-1487. EDX results showed that the carbonized result containing 90.10% carbon and 9.9% oxygen. Previously cellulose containing 47.49% Carbon, 48.40% Oxygen and 4.11% gold which was the result of the coating for sample preparation for SEM. While the FTIR results are unreadable due to carbonization change in the sample which makes the previous sample is polar to non-polar. Based on the results generated LCRmeter sample after carbonized is a good conductor.
Keyword: Bogor Agricultural University (IPB), XRD, graphite, FTIR, electrospinning, cotton

Judul: Pembuatan Serat Nano Kitosan/ Polyvinyl Alcohol/ Polyethylene Glycol dengan Metode Electrospinning : Kajian Viskositas Larutan
Abstrak: Metode electrospinning dalam pembuatan serat nano semakin banyak dikembangkan dari waktu ke waktu, karena proses sintesis yang cukup sederhana dan efektif dalam pembuatan serat nano. Sintesis serat nano dengan metode ini dilakukan pada sampel larutan PVA 7.5% dan 10% yang dicampur dengan larutan kitosan dan PEG. Hasil sintesis serat yang dihasilkan dilakukan pengujian mekanik, FTIR, dan SEM. Hasil uji tarik tertinggi didapat pada sampel PVA 7.5% dengan perbandingan konsentrasi PEG+kitosan:PVA 1:9 nilai Ultimate Tensile Strength (UTS) yaitu 8.843 MPa dan pada sampel PVA 10% dengan perbandingan PEG+kitosan:PVA 3:7 nilai Ultimate Tensile Strength yakni 8.85 MPa. Karakterisasi FTIR menujukkan adanya gugus fungsi pada PVA, PEG, dan kitosan. Morfologi serat nano dianalisis dengan menggunakan Scanning Electron Microscope (SEM). Serat yang dihasilkan berada pada rentang skala serat nano yakni mulai dari 60 nm sampai 200 nm.
Keyword: electrospinning, kitosan, PEG, PVA, serat nano, viskositas, electrospinning, kitosan, PEG, PVA, serat nano, viskositas

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model