Judul: Analisis Tensor Suseptibilitas Rank Empat pada Permukaan dan Bulk Perovskit MAPbI3 dengan Teori Grup
Abstrak: Dalam penelitian ini, tensor suseptibilitas rank empat dari bulk (point group D4h) dan permukaan (point group C2v) perovskit MAPbI3 dihitung dengan teori grup. Pencarian tensor dilakukan dengan mengoperasikan setiap operator simetri pada tiap kelas dari setiap point group. Dengan adanya prinsip Neumann, beberapa elemen tensor menjadi nol dan jumlah elemen independen dari tensor suseptibilitas dapat diperoleh. Ketika frekuensi medan listik yang diberikan hampir sama dengan frekuensi alami perovskit, terdapat 11 komponen independen untuk point group D4h pada bulk dan 21 komponen independen pada permukaan perovskit. Jika frekuensi medan listrik yang datang jauh berbeda dengan frekuensi alamiah perovskit (berlaku simetri Kleinman) maka komponen independen untuk point group D4h dan C2v kembali tereduksi menjadi 4 dan 6 komponen. Sehingga dapat dikatakan bahwa pembentukan generasi harrmonik orde tiga pada Kristal perovskit MAPbI3 pada permukaan dan bulk masing-masing hanya dipengaruhi oleh 4 dan 6 komponen independen.
Keyword: teori grup, grup D4h, grup C2v, perovskit, suseptibilitas

Judul: Separation of Isotropic and Anisotropic Tensor for MAPbI3 Perovskite Crystal Using Group Theory and Simplified Bond Hyperpolarizability Model.
Abstrak: Nonlinear phenomena occur when the electric field from a coherent and high-intensity light source interacts with the atoms in the material so that it oscillates anharmonically along the bond. Optical nonlinearities can be used as a method for analyzing the structure of optoelectronic materials such as perovskite. MAPbI3 is an optoelectronic material that has advantage in conservation efficiency, at room temperature MAPbI3 has an orthorhombic structure with C2v group points on the surface and D4h in the bulk perovskite section. This research separates the isotropic and anisotropic susceptibility tensors in the case of the second harmonic generation and the third harmonic generation and analyzes their contribution to total polarization. there are 6 isotropic non-zero tensor components and 13 non-zero anisotropic components in the C2V rank-3 structure and zero isotropic and anisotropic components in the D4h rank-3 structure. whereas there are 21 isotropic non-zero components at rank-4 of both structures and 20 and 8 non-zero anisotropic components at rank-4 surface and bulk perovskite. the contribution of 2nd order total polarization only occurs in anisotropic while for 3rd order, polarization isotropic and anisotropic contributing to total polarization
Keyword: Anisotropi, Isotropic

Judul: The Effect Cassava Leaves Meal in The Diets on Body Weigbt, Percentage of Digestive Tract and Viscera of Mule Duck.
Abstrak: The mule ducks are the crossbreed between common duck females (Anas plathyrhynchos) and muscovy ducks (Cairino moschata) to improve the meat production in order to meet the animal protein requirement of the people. One of the problems in husbandry farming is highly feed cost. This problem can be solved with using highly available local sources and cheapness. Cassava leaves (Manihot esculenta Crantz) is the one local sources which can be used as an alternative feed, because it contains a rather high protein (24.1%) aud vitamin A (10,000-13,000 IU). A highly Hydrocyanide (HCN) as well as crude fiber in the cassava leaves are the limiting factors to be used as poultry diet. The ducks have more ability in digest the crude fiber than chicken. So that, using some cassava leaves in the diet does not make any problem.
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