Judul: Analisis keragaman genetik dan sintasan sejumlah isolat bekteri fotosintetik anoksigenik asal laut
Abstrak: Eighty isolates of anoxygenic photosynthetic bacte- ria were isolated from 49 samples collected from a number of Indonesian seashores. All of the isolates showed similar color (i.e. photosynthetically in red to brownish red) when grown Sea Water Complete (SWC) medium. under illumination of tungsten light (± 200 lux). Many of the isolates were gram-negative, rod shape bacteria. However, genetic analysis employing Asel-schizotyping of 45 selected isolates indicated extensive genetic diversi- ty which apparently did not show any biogeographic relat- edness. A number their survival of selected isolates in sterile sea water were examined for supplemented with peptone (0,1 g/1) and yeast extract (0,02 g/1). All of the isolates demonstrated significant growth until 5 days of incubation and most of them maintained their viability up to 7 days of incubation. However, SKX121 is the only isolate which could maintain its viability up to 2 x 109 cell/ml after 7 days of incubation. From 47 isolates examined, 35 isolates were signifi- cantly more tolerant to Na2S (up to 100 µg/ml than isolate MW4, a reference isolate which has been known as sulphide tolerant anoxygenic photosynthetic bacteria.
Keyword: keragaman genetik, Bakteri fotosintetik, laut

Judul: Identification of Bacterial Isolates IR5 and IR9,  Relationships, Optimization of Media, and Synthesized Pigments
Abstrak: Bakteri isolat IR9 dan IR5 merupakan bakteri fotosintetik ungu yang biasa ditemukan di laut dan diketahui dapat menghasilkan pigmen. Isolat IR5 dan IR9 telah berhasil diisolasi dari laut. Penelitian ini bertujuan menganalisis kekerabatan antar kedua isolat tersebut berdasarkan sekuens 16S rRNA, mengoptimasi media pertumbuhan, dan mengidentifikasi jenis pigmen yang dihasilkan oleh kedua isolat tersebut. Analisis kekerabatan kedua isolat berdasarkan kemiripan sekuens 16S rRNA menunjukkan isolat IR5 dan IR9 tergolong ke dalam spesies Rhodovulum sulfidophilum. Kedua isolat tersebut diduga merupakan strain yang berbeda. Berdasarkan pengamatan secara kualitatif pada tingkat kepekatan warna kultur, isolat IR9 memiliki pertumbuhan yang lebih baik apabila dibandingkan dengan isolat IR5 pada media pertumbuhan yang sama. Komposisi media pertumbuhan yang paling optimum dan direkomendasikan untuk pertumbuhan isolat IR5 dan IR9 adalah 1% gula pasir + 0,5% NPK + 2,5% NaCl kasar. Media yang mengandung NPK mendukung pertumbuhan bakteri yang lebih optimum dibandingkan dengan media yang mengandung TSP tanpa NPK. Isolat bakteri IR9 mengalami pertumbuhan optimum pada hari ke-3. Identifikasi berdasarkan serapan panjang gelombang pada spektrofotometer UV-VIS menunjukkan bakteri tersebut mampu menghasilkan beberapa jenis pigmen, yaitu bacteriopheophytin, β-carotene, canthaxanthin, dan bacteriochlorophyll a.
Keyword: Identifikasi pigmen, kurva tumbuh, optimasi media, pohon filogenetik Rhodovulum sulfidophilum, Identifikasi pigmen, kurva tumbuh, optimasi media, pohon filogenetik Rhodovulum sulfidophilum

Judul: Modeling of inverted pendulum system with oblique trackand parameter characterizationon optimal tracking error problem
Abstrak: Inverted pendulum is an important device in education and research for control engineering. Many results of research are reached through study to pendulum system. The primary objective of this thesis is to characterize the inverted pendulum system with oblique trackon the optimal tracking error problem in terms of the system of parameters. We first derive the equations of motion for the pendulum system with flat track and the next endittothe system with oblique track.We then derive the analytical expressions of the optimal tracking error problem for both systems. It is shown that the expressions are completely determined by the pendulum’s parameters. Furtherm ore, its is shown that the lowest possible tracking error can be attained as long as the ratio between pendulum and motor masses is equal to a certain constant, regardless the material of the pendulum.
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