Synthesis and Characterization of Polystyrene-starch Polyblend

Polystyrene foam (PS) is a polymer that is widely used but not biodegradable. Therefore, PS-starch polyblend was developed. In this research the effect of glycerol as plasticizer was evaluated based on mechanical and thermal analyses. PS-starch polyblends were produced by mixing PS and starch solution with composition ratios of 60:40, 65:35, 70:30, 75:25, and 80:20 percent by weight. Polylactic acid (20%) was added as compatibilizer. The polyblends were analyzed its tensile strength, thermal properties, and density. The PS-starch polyblends were white opaque in color and fragile. The properties of tensile strength and density of the polyblends were in the range of that of pure PS. The tensile strength and density increases as PS constituents increasing with the best composition ratio of 80 PS to 20 of starch. Peak of glass transition and melting point seen a single on composition ration 80 PS to 20 of starch. Additional amount of glycerol did not affect the thermal property, but has caused a slight decrease in tensile strength and density

PENGARUH MODEL PEMBELAJARAN PROBLEM SOLVING SEARCH, SOLVE, CREATE, AND SHARE TERHADAP HASIL BELAJAR SISWA SMK PADA MATA PELAJARAN TEKNIK ELEKTRONIKA DASAR

Abstrak Penelitian ini bertujuan untuk mengetahui hasil belajar dan aktivitas belajar siswa dengan model pembelajaran problem solving search, solve, create, and share dibandingkan dengan model pembelajaran konvensional pada mata pelajaran teknik elektronika dasar di kelas X TAV SMK Negeri 2 Surabaya. Hasil belajar dan aktivitas siswa tersebut dibandingkan untuk mengetahui model pembelajaran dengan hasil yang terbaik. Jenis penelitian yang digunakan dalam penelitian ini adalah Jenis penelitian eksperimen. Desain penelitian yang digunakan adalah Nonequivalent Control Group Design yang termasuk kategori Quasi Experimental Design. Pengambilan sampel untuk kelas eksperimen dan kelas kontrol tidak dipilih secara acak, Kelas eksperimen menggunakan model pembelajaran problem solving search, solve, create, and share, sedangkan untuk kelas kontrol menggunakan model pembelajaran konvensional. Data penelitian berupa hasil belajar siswa diambil dengan teknik tes yang berupa pilihan ganda dan uraian. Hasil penelitian dan analisis data menunjukkan bahwa model pembelajaran problem solving search, solve, create, and share lebih baik dibandingkan model pembelajaran konvensional. Hal tersebut dibuktikan dengan hasil uji-t dimana t hitung > t tabel dengan taraf signifikansi α = 0,05 yakni hasil belajar kelas eksperimen diperoleh t hitung sebesar 2,78 dan t tabel sebesar 1,67 dan siswa yang menggunakan model pembelajaran problem solving search, solve, create, and share lebih aktif dibandingkan model pembelajaran konvensional yaitu sebesar 85,30% untuk kelas eksperimen dan 77,08% untuk kelas kontrol. Kata Kunci: Model pembelajaran problem solving search, solve, create, and share, Model pembelajaran konvensional, Hasil belajar siswa. Abstract This research aims to find out differences of student achievement and student learning activities, for student with  problem solving learning model type search, solve, creat and share compared by conventional learning model in basic of electronics subject in X TAV Classroom of SMK Negeri 2 Surabaya. both of student achievement and student learning activities are compared to determine which one the learning models with the best result. This research used experiments of research. The design is a nonequivalent control group design that included the category of Quasi Experimental Design. Sampling for the experimental class and the control class, not randomly chosen, the experimental class of problem solving learning model type search, solve, create, and share, while for control class using conventional learning models. Research data were taken in the form of student learning achievement with techniques test such as multiple-choice tests and descriptions. The results of the research and analysis of the data shows that the problem solving learning models type search, solve, create, and share better than conventional learning models. This is evidenced by the results of t-test where t count > t table with a significance level α = 0.05 the student achievement in experimental class obtained  2.78 for t count and 1.67 t table and student with problem solving learning models type search, solve, create, and share more active in learning than the student with conventional learning models, its determine by 85,30% for experiment class and 77,08% for control class. Keywords: Problem solving learning models type search, solve, create, and share, conventional learning models, student achievement

Determinan Kesediaan Nelayan Mengagunkan Sertifikat Hak Atas Tanah dan Dampaknya terhadap Pendapatan

This study aimed to analyze factors which influence or encourage the fishermen as the participants in land right certification program to be willing to secure their land certificate to obtain loans and to analyze the impact of land certification program for the fishermen to increase their income and welfare. The study was conducted in Indramayu as an area which has a fisherman land certification program. The data obtained in this study were analyzed by logistic regression and multiple linear regression. The logistic regression analysis was performed by using feasibility test model (goodness of fit) and Nagelkerke R Square Coefficient. Moreover, the multiple linear regression analysis was performed by using F Test and determination coefficient analysis (R²). The results showed that the fishermen status and educational background, land width, ownership of other assets and side business are included as factors that significantly influence the interest to use their land certificate obtained from "Fishermen Empowerment Program and Small-Scaled Fishery Businesses through the Certification of Land Right” as their collateral. The results were supported by highlighting that p-value for each variable is smaller than 0,10 and the educational factor has a significant effect which is higher than 0,009 compared to other factors. Having a higher education level encourages the fishermen to secure their land certificates in order to obtain capital in increasing their income and welfare

Studi Pemasangan Damping Reaktor untuk Mengatasi Feroresonansi pada Incoming 20 KV GIS Tandes

Pada studi ini, dilakukan simulasi pemasangan damping reaktor sebagai salah satu teknik mitigasi feroresonansi dengan menggunakan ATP Draw. Damping reaktor sebagai teknik mitigasi feroresonansi menggunakan elemen resistor yang dipasang di sisi primer transformer. Hasil dari simulasi pemasangan damping reaktor yang diperoleh berupa respon arus dan respon tegangan yang berubah terhadap waktu yang menunjukkan apakah feroresonansi dapat diredam atau tidak. Dari hasil simulasi pemasangan damping reaktor pada studi ini diperoleh bahwa feroresonansi dapat diredam dengan pemasangan nilai damping yang tepat. Sehingga dalam studi ini akan dibahas mengenai sejauh mana keefektifan dari pemasangan damping untuk meredam feroresonansi

Design new voltage balancing control series connected for HV-IGBT`s

The insulated gate bipolar transistors (IGBTs) are widely used in various applications as they require low gate drive power and gate voltage. This paper proposes an active gain circuit to maintain voltage stability of series-connected IGBTs for high voltage applications. The novel gate driver circuit with closed-loops control amplifies the gate signal while restricting the IGBT emitter voltage below a predetermined level. With the proposed circuit, serial-connected IGBTs can replace high-voltage IGBTs (HV-IGBTs) for high-voltage applications through the active control of the gate signal time delay. Closed-loop controls function is to charged current to the gate to restrict the IGBT emitter voltage to a predetermined level. This paper also presents the experiment on the gate driver capability based on a series-connected IGBTs with three IGBTs and a snubber circuit. The experimental results show a voltage offset with active control with a wide variation in load and imbalance conditions. Lastly, the experimental results are validated with the simulation results, where the simulation results agree with the experimental results

Reversing conditional orderings

We analyze some specific aspects concerning conditional orderings and relations among them. To this purpose we define a suitable concept of reversed conditional ordering and prove some related results. In particular we aim to compare the univariate stochastic orderings ≤ st, ≤ hr, and ≤ lr in terms of differences among different notions of conditional orderings. Some applications of our result to the analysis of positive dependence will be detailed. We concentrate attention to the case of a pair of scalar random variables X, Y ​. Suitable extensions to multivariate cases are possible