AbstrakTelah dilakukan penelitian tentang pengembangan media video penggunaan alat gelas di Laboratorium pada mahasiswa tahun I Program Studi Pendidikan Kimia, dengan tujuan menghasilkan video penggunaan alat gelas di laboratorium yang layak digunakan sebagai panduan mahasiswa program studi pendidikan kimia FKIP Universitas Khairun dalam melakukan praktikum. Media video pengguaan alat gelas di Laboratorium ini dikembangkan berdasarkan kaidah pengembangan media pembelajaran yang diadaptasi dari tahap pengembangan 4D. Metode pengembangan 4D memiliki 4 tahap pengembangan dinataranya: pendefinisian, perancangan, pengembangan dan penyebaran. Hasil pengembangan berupa video pengenalan dan penggunaan alat gelas di laboratorium dengan durasi 18 menit. Dari segi validitas media video, produk tersebut dinyatakan sangat valid oleh 3 orang validator dengan nilai rata-rata 3,81 dari skala 4 dengan kategori sangat valid. Produk media video juga diukur keterbacaannya oleh 10 mahasiswa prodi pendidikan kimia FKIP Universitas Khairun dengan persentase keterbacaan sebesar 79,17%. Sedangkan angka keterlaksanaan praktikum menggunakan panduan kedua video tersebut di Laboratorium sebesar 67,50%. Kata Kunci: Alat gelas laboratorium kimia; metode 4D, pengembangan video Video Development of Use of Chemical Laboratory Equipment in University Abstract
The optimization of molecular geometry, study of the quantitatife structureactivity relationship (QSAR) and multilinear regression (MLR) on derivatives benzopirazine compounds have been conducted with substitution groups electron (R7) donors such as:-Br,-COOH,-NH2,-NH3,-OH and-C5H6. Molecular structure model have been done with computationally using hyperchem 8.0.10 sofware. Results geometry optimization using the semi-emperical AM1 method show the total energy of each compound by A1-A6. Determine of the relationship between descriptors included Log P, Polari, SAG, SAA, EH, EHOMO, ELUMO, ΔEG, MD and clean charge with antimalarial activity (IC50 Experiments) shows a correlation. Descriptor show a relationship with antimalarian activity (IC50 Experiments) then, determined the best QSAR equal model condocted with multilinear regression analysis using SPSS 22 program. The results of analysis obtained for the best QSAR equation model found in model 4 equation: Log 1/IC50 = 2.357-(0.041) EH + (0.297) Polari-(0.
Sunscreen is an active ingredient capable of absorbing, reflecting, or dissipating UV radiation at a wavelength of 290-400 nm. Sunscreen cream can absorb at least 85 % of sunlight at a wavelength of 290-320 nm [1]. Exposure to excessive sunlight can cause skin wrinkles, black spots, premature aging to cause skin cancer. Ultraviolet rays can be divided into UV-A with wavelengths of 320-400 nm and UV-B rays with wavelengths 280-320 nm and UV-C rays of 100-280 nm length [2]. UV-A rays have less energy than UV-B and UV-C, but have a greater light identity up to the surface of the earth, causing skin discolouration to reddish brown. UV-B rays have greater energy than UV-A but fewer light intensities reach the surface of the earth so that less effect on the body. While UV-C rays are the highest and most dangerous UV rays among other UV rays but will naturally be absorbed by the ozone layer in atmospheres [3]. One way that is done to overcome this is with the use of sunscreen cream. Sunscreen is a compound that can be used to protect the skin from sunburn, especially ultra violet (UV). To protect the skin from UV radiation, it is made cosmetic sunscreen that can absorb ultraviolet rays from sunlight effectively. Sunscreen material can be obtained synthetically or naturally. Synthetic sunscreen materials are often used in sunscreen preparations as physical and chemical absorber. For UV blockers physically commonly used TiO 2 and ZnO to block UVB/UVA [4]. The
The optimization of molecular geometry and the modeling of electronic transition to anti-UV activities on anthocyanin derivatives in computationally have been conducted using the Hyperchem 8.0.10 application. Semi-empirical PM3 method is applied and the parameter of data is measured i.e. charge and total energy. The objective of study is to get a potential model of anthocyanin derivatives as anti-UV agents. The results show that each anthocyanin derivative has optimal geometry in stable energy. Electronic transition modeling of anthocyanin derivatives has been done using semi-empirical ZINDO/s method with a limited change of gradient 0.01 kcal/(Å.mol). The results show that the transition type in 10 anthocyanin derivatives is n → π⃰ and π → π⃰ with anti UV activity in the UV-A and UV-C wavelength regions. Electron excitation for each anthocyanin derivative occurs in four molecule orbitals. The energy difference of HOMO-LUMO shows that malvidin compound has the smallest energy gap which around 5.61, whereas the luteolinidin compound has the biggest energy gap which around 5.94 eV.
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