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: Penjadwalan Mata Pelajaran di Sekolah: Studi Kasus di SMPIT Nurul Fajar Bogor
Abstrak: Scheduling is one of the problems faced by many institutions including schools. However, the conventional scheduling is often sub-optimal. In this work, the scheduling problem is modeled mathematically using integer programming approach. In this paper the problem of scheduling of courses was formulated into integer nonlinear programming. The model is then implemented to solve the courses scheduling problem in SMPIT Nurul Fajar School Bogor. The computer software LINGO 11.0 was used to obtain optimal solutions in the form of courses and satisfying all constraints of subject and teachers’ schedules.
Keyword: Bogor Agricultural University (IPB), school., courses, scheduling, integer nonlinear programming

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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