Development of Module With Concept Maps and Picture on The Diversity of Living Things Materials for Students Class VII Junior High School

The purpose of this study produce teaching materials in the form of modules that is equipped with concept maps and images for the seventh grade students of junior high school, valid and practical. This study uses three steps of the model 4-D namely, define, design, and development. Subject 4 validators, 2 teachers, and 20 students at 26 public Junior High School in Padang. The data in this study are primary data collected from the questionnaire validity and practicalities. Results of product testing are developed, acquired valid and very practical criteria of the results by the lecturers, teachers, and students

Biosintesis ZnO Nanopartikel dari Ekstrak Air Daun Jambu Biji (Psidium guajava L) dan Ion Zn2+ serta Interaksinya dengan Kitosan sebagai Antibakteri Escherichia coli

The biosynthesis of ZnO nanoparticles and chitosan-ZnO nanoparticles has been carried out. The aims of this research were to modify and characterize of chitosan-ZnO nanoparticles and their application as an antibacterial agent of Escherichia coli. The characterization of chitosan-ZnO nanoparticles was conducted by FTIR spectroscopy and X-Ray diffractometer. ZnO nanoparticle was synthesized by the reaction between leaf extract of the common guava (Psidium guajava L) and zinc acetate dihydrate. Chitosan-ZnO nanoparticles were synthesized by the reaction between chitosan and ZnO nanoparticles. The agar diffusion method was used to study the antibacterial activity of chitosan-ZnO nanoparticles. The result showed that the wavenumber of FTIR spectra chitosan-ZnO nanoparticles appeared at 3427 cm−1. The crystalline size of ZnO nanoparticles was 16.54 nm. The average inhibition zone of chitosan-ZnO nanoparticles at concentration 10,000; 5,000; and 2.500 mg/L were 30.57 ± 0.87; 25.97 ± 1.42; and 23.10 ± 1.61 mm, respectively. The higher the concentration of chitosan-ZnO nanoparticles, the greater the inhibition zone.Pada penelitian ini telah dilakukan biosintesis ZnO nanopartikel dan kitosan-ZnO nanopartikel sebagai antibakteri Escherichia coli. Tujuan dari penelitian ini adalah modifikasi dan karakterisasi kitosan dengan ZnO nanopartikel dan aplikasinya sebagai antibakteri Escherichia coli. Karakterisasi kitosan-ZnO nanopartikel dilakukan dengan menggunakan spektrofotomer FTIR dan difraksi sinar X (XRD). Difraksi sinar X (XRD) digunakan untuk karakterisasi ZnO nanopartikel. ZnO nanopartikel disintesis melalui reaksi antara ekstrak air daun jambu biji (Psidium guajava L) dengan seng asetat dihidrat. Kitosan-ZnO nanopartikel disintesis melalui reaksi antara kitosan dan ZnO nanopartikel. Metode diffusi agar digunakan untuk meneliti kitosan-ZnO nanopartikel sebagai antibakteri. Hasil penelitian menunjukan bahwa bilangan gelombang pada spektra FTIR kitosan-ZnO nanopartikel muncul pada 3427 cm−1. Ukuran kristal ZnO nanopartikel adalah 16,54 nm. Rata-rata zona inhibisi dari kitosan-ZnO nanopartikel pada konsentrasi 10.000, 5.000 dan 2.500 mg/L berturut-turut adalah 30,57 ± 0,87; 25,97 ± 1,42; dan 23,10 ± 1,61 mm. Semakin tinggi konsentrasi nanopartikel kitosan-ZnO, maka semakin besar pula zona hambatnya