Judul: Characteristics of Bokashi Fertilizer Residue Salt Seaweed Sargassum sp. Using Local Banana Peel Microorganisms
Abstrak: Residu garam rumput laut Sargassum sp. mengandung makro dan mikronutrien, hormon yang mendorong pertumbuhan, protein, dan vitamin. Salah satu pemanfaatan residu garam rumput laut Sargassum sp. bisa dijadikan sebagai bahan baku dalam pembuatan pupuk bokashi. Limbah kulit pisang uli memiliki potensi untuk dimanfaatkan sebagai bahan baku penumbuhan mikroorganisme lokal (MOL). Penelitian ini bertujuan menentukan konsentrasi terbaik residu garam rumput laut Sargassum sp. yang ditambahkan MOL kulit pisang uli pada pupuk bokashi. Penelitian dilakukan dengan penumbuhan mikroorganisme lokal, pembuatan pupuk bokashi, pengujian pH, C-Organik, N-Total, P2O5, K2O, kadar air, serta analisis data. Konsentrasi terbaik pada pupuk bokashi terdapat pada perlakuan F3 (Residu garam rumput laut Sargassum sp. 53%, sekam 10%, dedak 3%, dan MOL 34%) yang memiliki kandungan pH 8,14, C-Organik 38,25%, N-Total 1,17%, P2O5 0,25%, K2O 6,98%, dan kadar air 26,18%). Kandungan unsur hara pupuk bokashi residu garam rumput laut Sargassum sp. menggunakan mikroorganisme lokal kulit pisang uli memilki unsur hara yang cukup baik untuk tanaman., Seaweed salt residue Sargassum sp. contains macro and micronutrients, hormones that promote growth, protein and vitamins. One use of seaweed salt residue is Sargassum sp. can be used as raw material in making bokashi fertilizer. Uli banana peel waste has the potential to be used as raw material for growing local microorganisms (MOL). This study aims to determine the best concentration of seaweed salt residue Sargassum sp. MOL uli banana peel is added to bokashi fertilizer. The study was conducted by growing local microorganisms, making bokashi fertilizer, testing pH, C-Organic, N-Total, P2O5, K2O, water content, and data analysis. The best concentration of bokashi fertilizer is in the F3 treatment (Sargassum sp. seaweed salt residue 53%, 10% husk, 3% bran, and 34% MOL) which has a pH content of 8,14, C-Organic 38,25%, N-Total 1,17%, P2O5 0,25%, K2O 6,98%, and water content 26,18%). The nutrient content of bokashi fertilizer from Sargassum sp. seaweed salt residue using
Keyword: C-Organik, Fosfor, Hara, Kalium, MOL, dan Nitrogen

Judul: Microscopic structure and functional structure of Seaweed Salt Ulva and Sargassum Polycystum
Abstrak: Rumput laut dapat dikembangkan menjadi garam fungsional yang memiliki manfaat salah satunya antihipertensi. Penelitian ini bertujuan untuk menentukan struktur mikroskopik dan gugus fungsi garam rumput laut dengan beberapa perbandingan konsentrasi residu rumput laut dari rumput laut dari Ulva lactuca dan Sargassum polycytsum. Tahapan penelitian meliputi preparasi sampel, pembuatan tepung dan garam rumput laut serta mengkarakterisasi fisik garam rumput laut. Garam rumput laut Ulva lactuca dan Sargassum polycystum mengandung kadar abu 41,05%, 27,50% dan kadar protein 7,33%, 7,04%. Hasil terbaik pada uji sensori adalah garam rumput laut Ulva lactuca 1:2 dan Sargassum polycystum 2:1. Hasil identifikasi mikroskopis Scanning Electron Microscope (SEM) menunjukkan perbesaran terbaik pada perbesaran 5000x dan Particle Size Analyzer (PSA) menunjukkan ukuran partikel signifikan terbaik 720,25±123,25 (nm) pada garam Ulva lactuca residu 1:2 dengan indeks keseragaman polidispersitas 0.68±0,17. Gugus fungsi yang terdeteksi hasil FTIR yaitu Hidroksil (OH), Medial alkkyne (C≡C), asam karboksilat asimetrik dan simetrik (C=C), amida III (C-N), alifatik berfluor dengan gugus fungsi C-F, aliphatic phosphates (P-O-C), menunjukkan gugus fungsi metal oxygen bonding, gugus fungsi C-H dan gugus fungsi aryl disulfides (S-S)., Seaweed can be developed into functional salts which have antihypertensive benefits. This study aims to determine the microscopic structure and functional groups of seaweed salt with several comparisons of concentrations of seaweed residues from seaweed from Ulva lactuca and Sargassum polycytsum. The stages of the research included sample preparation, manufacture of seaweed flour and salt and physical characterization of seaweed salt. Seaweed salt Ulva lactuca and Sargassum polycystum contain ash content of 41.05%, 27.50% and protein content of 7.33%, 7.04%. The best results in the sensory test were Ulva lactuca seaweed salt 1:2 and Sargassum polycystum 2:1. Microscopic identification of the Scanning Electron Microscope (SEM) showed the best magnification at 5000x magnification and the Particle Size Analyzer (PSA) showed the best significant particle size of 720.25 ± 123.25 (nm) in Ulva lactuca salt residue 1: 2 with a polydispersity uniformity index of 0.68 ± 0.17. The functional groups detected by the FTIR results were Hydroxyl (OH), Medial alkkyne (C≡C), asymmetric and symmetric carboxylic acids (C=C), amides III (C-N), fluorine aliphatic with C-F functional groups, aliphatic phosphates (P O-C), shows the metal oxygen bonding functional group, the C-H functional group and the aryl disulfides (S-S) functional group.
Keyword: FTIR, salt, PSA, seawead, sensory, SEM, PSA

Judul: Penyelesaian Masalah Rotasi Aliran Fluida Kental Von Karman Menggunakan Metode Homotopi
Abstrak: Von Karman equation is an equation that describes fluid viscous flow induced by infinite disk rotation. By assuming steady flow and laminar, viscous incompressible fluid flow is represented in Von Karman equation by an angular velocity and the vertical direction velocity as the independent variables. Von Karman equation is a nonlinear problem that is solved using the homotopy method. The use of homotopy method is done by defining an homotopy function that requires auxiliary parameters to control the convergent region of the solution. The solution is a recursive formula with given initial conditions. Using software based-functional shows that velocity components converge to a value.
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