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

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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.

Geometric modeling and geometric optimization of Fe(III)-1,10-phenantroline (Fe-Phen), Ni II)-1,10-phenantroline (Ni-Phen) and Zn(II)-1,10-phenantroline (Zn-Phen) compounds have been carried out computing using the semi-empirical method of PM3. The spectral measurements and the study of complex electronic compositions using the UV-Vis spectrophotometer and simulation of ZINDO/s (Zerner's Neglect of Differential Overlap) calculations. The optimum result of the geometry of complex molecule found there is a change of charge in each complex with stable energy. The UV-Vis spectra measurements showed λmax in the Fe-Phen complex: 315.50 nm, Ni-Phen complex: 325.00 nm and Zn-Phen complex: 315.00 nm. The electronic transition occurring at these three complexes shows the transition characteristics of electrons at the level of the molecular orbitals π to π* and the degree of the molecular orbitals n to π⃰. Electron transition energy in complex orbital molecules can be observed in the energy changes of each molecular orbitals.

Infrastructure in the coastal area is mostly made of steel and reinforced concrete steel which is susceptible to corrosion due to direct contact with sea water and also climatic conditions. There are several ways that can slow down the rate of corrosion reaction, one of which is by adding certain substances that act as inhibitors of corrosion reactions. This study is to determine the effect of using Rice Husk Ash as a natural inhibitor to reinforcing reinforced concrete reinforcement. The inhibitors used were rice husk ash mixed with reinforced concrete mixture as much as 5% and 10%. This corrosion measurement by calculating the weight lost from the reinforcement (inhibition efficiency). From the experimental results show that the higher the concentration given the lower the corrosion rate, and the optimal conditions obtained the effect of the use of natural inhibitors (rice husk ash) to reinforcing steel corrosion on the addition of 10% inhibitor of rice husk ash ash by 96%.

An investigation on dolabellane derivatives to understand their potential in inhibiting the SARS-CoV-2 main protease (3CLpro) using an in silico approach.