Judul: Penjadwalan Mata Kuliah dengan Meminimumkan Banyaknya Ruangan
Abstrak: Course scheduling at Common First Year Program of Bogor Agricultural University (also known as TPB IPB) is determined by the number of available classrooms and the number of courses that are offered at TPB IPB. The university has to offer all of the courses that have to be taken by all of the first year students at IPB. All of the students are divided into a number of paralel classes. The size of the first year students implied the number of paralel classes is large, and this will increase the complexity of scheduling process.This study presents an optimization model for class scheduling at TPB IPB. Optimization model uses integer programming whose objective function is to minimize the number of required classrooms. The solution of the model is the schedule for each class for each course offered by TPB IPB, and the schedule obtained requires the minimum number of classrooms.
Keyword: Bogor Agricultural University (IPB), scheduling, integer programming, optimization

Judul: Scheduling of Lectures at the Educational of General Competence  Program IPB
Abstrak: Penjadwalan perkuliahan merupakan masalah yang sering dihadapi oleh setiap perguruan tinggi termaksud Program Pendidikan Kompetensi Umum (PPKU) Institut Pertanian Bogor (IPB). PPKU menyusun penjadwalan perkuliahan untuk semua mahasiswa baru dari berbagai program studi di IPB. Penjadwalan ini perlu memperhatikan banyak aspek-aspek seperti waktu, ruangan, dan sebagainya. Pemodelan ini dimodelkan dalam bentuk integer programming dengan tujuan meminimalkan kegiatan perkuliahan pada waktu-waktu tertentu yang dihindari, yaitu periode waktu yang dianggap terlalu pagi (07.00-08.00 WIB), waktu istirahat makan siang (12.00-13.00 WIB), terlalu sore (17.00-18.00 WIB), dan Rapat Rabuan dosen (10.00-12.00 WIB). Dari hasil implementasi, diperoleh penjadwalan perkuliahan yang memenuhi segala ketentuan yang ada., Lecture scheduling is a problem often faced by every university, including the Educational of General Competence Program (PPKU) at Bogor Agricultural University (IPB). PPKU prepares lecture schedules for all new students from various study programs at IPB. Scheduling requires attention to details such as time and location. This modeling is in the form of integer programming with the goals to minimize class schedules at specific avoided times, namely the earliest time slot (07.00-08.00 WIB), lunch break (12.00- 13.00 WIB), the latest time slot (17.00-18.00 WIB), and regular Wednesday lecturer’s meeting (10.00-12.00 WIB). After analyzing the implementation results, we have obtained a lecture schedule that satisfies all the given conditions.
Keyword: courses, educational of general competence program, integer programming, scheduling

Judul: Extraction and Characteristic of Collagen and Nanoparticle Collagen from the Skin of Stingray Fish (Pastinachus solocirostris) as Ingredient of Cosmetics.
Abstrak: Isolation of collagen from the skin of stingray fish (Pastinachus solocirostris) has been successfully conducted with three stages: first soaked in 0.05 M NaOH with a sample/solution ratio of 1:10 (w/v) for 6 hour, second soaked in 0.1 M acetic acid with a sample/solution ratio of 1:6 (w/v) for 2 hour, and third extraction with destilated water at temperature 40 C for 2 hour with a yield of 14.475 % (wet base). Nanoparticle collagen was made with desolvation method using etanol as a desolvating agent with a collagen solution/etanol ratio of 1:1. Yield of nanoparticle collagen was 9.64% (wet base) with particle size of 185.24 nm. Collagen and nanoparticle collagen is in the form of white powder with whiteness degree 72.48% and 60.03%, respectively. Protein is the major component in collagen and nanoparticle collagen (86.97% and 86.18%) with trace amount of ash (0.17% and 0.13%) and fat (0.19% and 0.25%), respectively. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns, amino acid composition, and fourier transform infrared (FTIR) spectra of both collagen and nanoparticle collagen were characterized as type I collagens. Nanostructural analysis of collagen and nanoparticle collagen by Scanning Electron Microscopy (SEM) shows that both were separate aggregates. Other characteristics of collagen and nanoparticle collagen were: Tmax of 165.88 C and 156.63 C; Viscosity 292.33 cP dan 110 cP; pH 5.00 dan 4.93; respectively. Collagen has highest solubility at pH 7 and the isoelectric point at pH 6, 9, and 10. Therefore, nanoparticle collagen has highest solubility at pH 3 dan and the isoelectric point at pH 6. Collagen and nanoparticle collagen from skin of stingray fish (Pastinachus solocirostris) has a characteristic for a potential use as a cosmetic ingredient.
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