Study of Effect of Weight Ratio on Copolymerization of Chitosan and Acrylamide

The use of chitosan as adsorbent in wastewater treatment has received a lot of attention. This is because the price of chitosan is cheap and easy to obtain. The application of chitosan as an adsorbent has the disadvantage of being soluble in acidic medium (pH <6.5), insoluble in water and organic solvents. Other disadvantages of chitosan are low adsorption capacity, and lack of selectivity. In this research, chitosan copolymer synthesis with acrylamide has been carried out by varying chitosan and acrylamide, namely 1:1, 2: 3 and 3: 2 using a microwave oven. The copolymers were characterized using FTIR, XRD, SEM and TGA/DTA. The results of the synthesis of chitosan copolymer with acrylamide were obtained the largest percentage of grafting at a ratio of 2: 3.  From the results of FTIR analysis showed that the copolymer had been successfully synthesized. XRD analysis showed that the copolymers synthesized have amorphous properties compared to chitosan. The results of SEM analysis, the copolymers had a porous structure. Thermal analysis showed that the copolymers have better thermal stability than chitosan. The chitosan-acrylamide copolymer which was synthesized in a ratio of 2: 3 has better properties

PENINGKATAN PENYESUAIAN DIRI SISWA MELALUI LAYANAN INFORMASI

Adaptability is essential for the student, because influence friends and social environment determine its succes. The fact that found in Junior High School 1 Padang Panjang discovered a less harmonious relationship of students with one class in learning. The research aims to uncover how the adaptability of the students before and after the given information services. This research using the method of experiment with the types of the one group pretest-posttest design. Population research is grade VII in Junior Hihg School 1 Padang Panjang the length of 261 student with a total samples of 34 students. The data collected using  the  question  form.  Data  analysis  techniques  using  two  different  test average of samples that are related (paired sample t-tests) by using the help program Statistical Product and Service Solution (SPSS) version 17.0. Research findings  show  there  is  a  difference  of  adaptability  of  students  Junior  Hihg School 1 Padang Panjng, before the give information services received an average score of 123,382. Adaptability of students after being given information services increased by average score of 127,735

Pemodelan Multivariate Adaptive Gamma Regression Spline (Studi Kasus: Persentase Kemiskinan Di Kawasan Timur Indonesia Tahun 2021)

Model regresi merupakan aplikasi model linier yang mengasumsikan bahwa error atau residual berdistribusi normal. Akan tetapi, pada praktiknya, asumsi ini seringkali tidak terpenuhi. Metode alternatif yang bisa diaplikasikan untuk data berdistribusi tidak normal adalah Generalized Linear Models (GLM). Regresi gamma merupakan kasus khusus dari GLM dan sering digunakan untuk memodelkan fenomena kontinu dengan skewness positif. Regresi gamma mengasumsikan bahwa variabel respon Y mengikuti distribusi gamma. Multivariate Adaptive Regression Spline (MARS) merupakan metode nonparametrik yang dapat digunakan untuk mengatasi permasalahan data berdimensi sedang hingga tinggi,3≤p≤20, dan data dengan jumlah sampel sedang,50≤n≤1000. Penggabungan antara metode MARS dan regresi gamma menghasilkan suatu metode baru yaitu Multivariate Adaptive Gamma Regression Spline (MAGRS). Penaksiran parameter model MAGRS menggunakan metode Weighted Least Square (WLS). Pengujian hipotesis parameter secara serentak menggunakan Maximum Likelihood Ratio Test (MLRT), sedangkan pengujian secara parsial menggunakan statistik uji Z. Model MAGRS diaplikasikan pada persentase kemiskinan di Kawasan Timur Indonesia (KTI) tahun 2021. Unit penelitian terdiri dari 176 kabupaten/kota. Variabel prediktor yang digunakan dalam penelitian sebanyak tujuh variabel. Variabel yang berpengaruh signifikan terhadap persentase kemiskinan di KTI adalah kepadatan penduduk, rasio ketergantungan, angka kesakitan, PDRB per kapita, konsumsi rumah tangga, dan Gini ratio, sedangkan pertumbuhan ekonomi tidak berpengaruh. Berdasarkan tingkat kepentingan variabel, tiga variabel yang berkontribusi besar dalam pembentukan model MAGRS pada persentase kemiskinan di KTI adalah kepadatan penduduk, PDRB per kapita, dan Gini ratio. Tingkat kepentingan variabel kepadatan penduduk adalah sebesar 100 persen, PDRB per kapita sebesar 78,2 persen, dan Gini ratio sebesar 59,8 persen. =============================================================================================================================== The regression model is a linear model application that assumes that the error or residual is a normal distribution. However, in practice, this assumption is often not met. An alternative method that can be applied to non-normally distributed data is Generalized Linear Models (GLM). Gamma regression is a special case of GLM and is often used to model continuous phenomena with positive skewness. Gamma regression assumes that the response variable Y follows a gamma distribution. Multivariate Adaptive Regression Spline (MARS) is a nonparametric method that can be used to solve problems with moderate to high dimensional data,3≤p≤20 and data with moderate sample sizes,50≤n≤1000. The MARS method and gamma regression combination produce a new method: the Multivariate Adaptive Gamma Regression Spline (MAGRS). Parameter estimation of the MAGRS model uses the Weighted Least Square (WLS) method. Simultaneous parameter hypothesis testing uses the Maximum Likelihood Ratio Test (MLRT), while partial testing uses the Z test statistic. The MAGRS model was applied to the poverty percentage in Eastern Indonesia in 2021. The research unit consists of 176 regencies/cities. The predictor variables used in the study were seven variables. Variables that have a significant effect on the poverty percentage in Eastern Indonesia are population density, dependency ratio, morbidity rate, GRDP per capita, household consumption, and Gini ratio, while economic growth has no effect. Based on the relative variable importance, three variables that contribute significantly to the formation of the MAGRS model on the poverty percentage in Eastern Indonesia are population density, GRDP per capita, and Gini ratio. The relative variable importance of the population density is 100 percent, GRDP per capita is 78.2 percent, and Gini ratio is 59.8 percent