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Abstrak :
Influences of fluorine containing compounds TiF4 and ZrF4 on hydrogen sorption properties of LiBH4 have been investigated. Thermovolumetric measurements, titration, and XRD technique were used to characterize the samples. The results demonstrated a pronounced beneficial effect of both ZrF4 and TiF4 on the sorption properties of modified LiBH4. After hydrogenation at 400°C and 80 bar, formation of modified LiBH4 was observed as a consequence of F dissolution in LiH (LiH1-zFz). Adding TiF4 and ZrF4 to LiBH4 has been found to modify both thermodynamic and kinetic properties.

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ABSTRAK
Tujuan dari penelitian ini adalah untuk membandingkan efektivitas campuran enzim selulase kasar dari Trichoderma reesei dan Aspergillus niger dengan selulase A. niger komersial dari Fluka Biochemika serta mempelajari pengaruh ratio enzim dengan substrat terhadap unjuk kerja hidrolisis. Enzim kasar dibuat dengan cara fermentasi padat dengan media sederhana. Satu unit aktivitas selulase kasar dari A. niger dicampur dengan dua unit aktivitas selulase kasar dari T. reesei. Jerami padi yang akan dihidrolisis terlebih dahulu digiling dan diayak 120?140 mesh kemudian didelignifikasi menggunakan larutan NaOH 2% selama 6 jam pada temperatur 85oC. Hidrolisis dilakukan dalam beaker glass 300 mL yang dilengkapi dengan pengaduk bermotor. Sampel dianalisis menggunakan metoda dintrosalicylic acid. Hasil percobaan menunjukkan bahwa peningkatan rasio enzim terhadap jerami padi dapat meningkatkan konsentrasi glukosa yang dihasilkan baik untuk enzim komersial maupun campuran enzim kasar. Campuran enzim selulase kasar dari T.reesei dan A. niger yang dihasilkan dari percobaan ini, dua kali lebih efektif menghidrolisis jerami padi menjadi glukosa dibandingkan dengan selulase komersial.

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Abstract
The objective of this work is to compare the effectiveness of mixed crude enzyme cellulase from T. reesei and A. niger with commercial enzyme from A. niger, and to investigate effect of enzyme to substrate ratio to performance of enzymatic hydrolysis of rice straw. The commercial enzyme from Fluka Biochemica was used, and crude enzyme were prepared by solid fermentation with simple media. Before hydrolized, the rice straw was grinded and sieved and then heated at 85oC with 2% sodium hydroxide for six hours. Hydrolysis was conducted in 300 mL beaker flask equipped with mechanical stirrer. Samples were analyzed by dinitrosalicylic acid method and measured by spectrophotometer. Both of commercial and mixed crude enzyme show that, the higher enzyme to substrate ratio was higher the glucose concentration obtained. However, ratio of glucose obtained to enzyme used become smaller. The mixture of crude enzyme from T. reesesi dan A. niger that produced in this work was two fold more effective to hydrolyze rice straw than using cellulase enzyme of A. niger from Fluka Biochemika.

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Studi ini dibuat untuk memenuhi informasi kualitatif aliran dan efek blockage pada interseksi unsymmetrical wing dengan flat surface. Kajian menggunakan computational fluid dynamics untuk memberikan informasi pola pathlines dan distribusi isototal static pressure daerah sambungan. Hasil -hasil penelitian ini menunjukkan pola aliran dipengaruhi angle of attack. Bertambahnya angle of attack menjadikan posisi saddle point bergerak menuju lower side dan menjauhi permukaan wing. Sedangkan, separation line atau imprint horseshoe vortex karena membesarnya angle of attack menjadi terbuka lebih lebar. Hasil - hasil kontur isototal static pressure menunjukkan bahwa lokasi dampak blockage semakin lebar menuju downstream trailing edge. Demikian juga bertambahnya angle of ttack menjadikan daerah efek blockage pada pressure side dan suction side semakin lebar.

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Abstract
The study was made to obtain qualitatively information about flow and blockage effect on unsymmetrical wing with flat surface intersection. The computational fluid dynamics was used in order to gain information of the pathlines patterns and the distribution of isototal static pressure on the junction region. Results show that an increase of angle of attack will move the saddle point to the lower side away from the wing surface. Meanwhile the separation line or imprint horseshoe vortex that resulted by the increase of angle of attack, will become wider. The isototal static pressure contour shows that the location which are effected by blockage are wider toward the downstream trailing edge. And as the an gleof attack increase, the area that are effected by blockage on pressure side and suction side will become even wider.

Abstrak :
Komposit matrik almunium dan penguat keramik termasuk jenis Metal Matrix Composites (MMCs) yang banyak dikembangkan sebagai komponen otomotif. Dalam penelitian ini digunakan matrik aluminium dan penguat serbuk alumina (Al2O3) dengan fraksi volume penguat 10%, 20%, 30% dan 40%. Pelapisan serbuk Al2O3 dengan Al+Mg dilakukan dengan menggunakan metode electroless plating. Berdasarkan hasil penelitian, didapatkan bahwa pada komposit dengan penguat yang dilapisi Al+Mg memiliki kualitas ikatan antar muka yang lebih baik dibandingkan dengan tanpa pelapis. Berdasarkan hasil pengujian kompresi, Modulus elastisitas tertinggi pada komposit Al/Al2O3 terlapisi MgAl2O4 diperoleh pada fraksi volume 40 % yaitu sebesar 259,9 GPa. Sedangkan modulus elastisitas komposit tanpa pelapisan pada fraksi volume 40% sebesar 178,8 Gpa, atau kenaikan sekitar 45%.

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Abstract
Aluminum matrix composite which was reinforced by ceramic is one of MMCs which is developed as automotive part. This current research use aluminum as matrix and alumina (Al2O3) powderas reinforced with volume fraction of 10%, 20%, 30%, 40%. With Almg coatied by electroless. The result show that composite with Al+Mg coating owned better interfacial bonding than composite without coating. The highest elasticity moduli of Al/ Al2O3 is forward at volume fraction of 40% is 259,9 GPa. However elasticity modulus of composite without coating treatment with volume fraction 40% is 178,8 GPa, or increased about 45%.

Abstrak :
PSS (Power system stabilizer) telah digunakan secara luas untuk memperbaiki stabilitas sistem tenaga listrik modern. Dalam makalah ini diusulkan perancangan sistematik PSS dengan Particle Swarm Optimization (PSO) sebagai metode optimasi penalaan parameter PSS. Penalaan parameter PSS dilakukan untuk mendapatkan sistem tenaga listrik yang stabil dan teredam secara optimal. Kriteria optimal yang digunakan dalam proses penalaan parameter adalah indeks performansi Integral of Time multiplied by Absolute Error (ITAE). Performansi dari PSS ini diujikan pada sistem tenaga listrik mesin tunggal dibawah gangguan kecil, kondisi beban dan parameter tertentu. Hasil analisa nilaieigen dan simulasi menunjukkan bahwa osilasi sistem tenaga listrik dapat teredam secara optimal melalui penalaan PSS berbasis PSO ini. Hasil simulasi juga menunjukkan bahwa performansi dinamik PSS berbasis PSO lebih baik dibandingkan PSS yang ditala secara konvensional.

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Abstract
Power system stabilizer (PSS) have been extensively used in modern power system for enhancing stability of the system. This paper presents a new systematic approach for the design of power system stabilizer using PSO (Particle Swarm Optimization). The proposed approach employs PSO search for optimal setting of PSS parameters. The optimal criteria of the Integral of Time multiplied by Absolute Error (ITAE) is used to search optimal setting. The performance of the proposed PSS under small disturbances, loading conditions and system parameters is tested. The eigenvalue analysis and simulation results show the effectiveness of the PSO based PSS to damp out the system oscillations. It is found that the dynamic performance with the PSO based PSS shows improved results, over conventionally tuned PSS.

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Ekstraksi informasi merupakan sebuah tahap awal dari proses analisis data tekstual. Ekstraksi informasi diperlukan untuk mendapatkan informasi dari data tekstual sehingga dapat digunakan untuk proses analisis seperti misalnya klasifikasi dan kategorisasi. Data tekstual sangat dipengaruhi oleh bahasa, jika sebuah data tekstual berbahasa Arab maka karakter yang digunakan adalah karakter arab. Knowledge dictionary merupakan sebuah kamus yang dapat digunakan untuk mengekstraksi informasi dari data tekstual. Informasi yang diekstraksi menggunakan knowledge dictionary adalah konsep. Knowledge dictionary biasanya dibangun secara manual oleh seorang pakar yang tentunya membutuhkan waktu yang lama dan spesifik untuk setiap masalah. Pada penelitian ini diusulkan sebuah metode untuk membangun knowledge dictionary secara otomatis. Pembentukan knowledge dictionary dilakukan dengan cara mengelompokkan kalimat yang memiliki konsep yang sama, dengan asumsi kalimat yang memiliki konsep yang sama akan memiliki nilai simi laritas yang tinggi. Konsep yang telah diekstraksi dapat digunakan sebagai fitur untuk proses komputasi berikutnya misalnya klasifikasi ataupun kategorisasi. Dataset yang digunakan dalam penelitian ini adalah dataset teks Arab. Hasil ekstraksi diuji dengan menggunakan mesin klasifikasi decision tree dan didapatkan nilai presisi tertinggi 71,0% dan nilai recall tertinggi 75,0%.

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Abstract
Information extraction is an early stage of a process of textual data analysis. Information extraction is required to get information from textual data that can be used for process analysis, such as classification and categorization. A textual data is strongly influenced by the language. Arabic is gaining a significant attention in many studies because Arabic language is very different from others, and in contrast to other languages, tools and research on the Arabic language is still lacking. The information extracted using the knowledge dictionary is a concept of expression. A knowledge dictionary is usually constructed manually by an expert and this would take a long time and is specific to a problem only. This paper proposed a method for automatically building a knowledge dictionary. Dictionary knowledge is formed by classifying sentences having the same concept, assuming that they will have a high similarity value. The concept that has been extracted can be used as features for subsequent computational process such as classification or categorization. Dataset used in this paper was the Arabic text dataset. Extraction result was tested by using a decision tree classification engine and the highest precision value obtained was 71.0% while the highest recall value was 75.0%.

Abstrak :
Cassava pulp, a low cost solid byproduct of cassava starch industry, has been proposed as a high potential ethanolicfermentation substrate due to its high residual starch level, low ash content and small particle size of the lignocellulosic fibers. As the economic feasibility depends on complete degradation of the polysaccharides to fermentable glucose, the comparative hydrolytic potential of cassava pulp by six commercial enzymes were studied. Raw cassava pulp (12% w/v, particle size <320 μm) hydrolyzed by both commercial pectinolytic (1) and amylolytic (2) enzymes cocktail, yielded 70.06% DE. Hydrothermal treatment of cassava pulp enhanced its susceptibility to enzymatic cleavageas compared to non-hydrothermal treatment raw cassava pulp. Hydrothermal pretreatment has shown that a glucoamylase (3) was the most effective enzyme for hydrolysis process of cassava pulp at temperature 65°C or 95°C for 10 min and yielded approximately 86.22% and 90.18% DE, respectively. Enzymatic pretreatment increased cassava pulp vulnerability to cellulase attacks. The optimum conditions for enzymatic pretreatment of 30% (w/v) cassava pulp by a potent cellulolytic/ hemicellulolytic enzyme (4) was achieves at 50 °C for 3, meanwhile for liquefaction and saccharification by a thermo-stable α-amylase (5) was achieved at 95°C for 1 and a glucoamylase (3) at 50°C for 24 hours, respectively, yielded a reducing sugar level up to 94,1% DE. The high yield of glucose indicates the potential use of enzymatic-hydrothermally treated cassava pulp as a cheap substrate for ethanol production.

Abstrak :
The increase of fuel price has caused fleet operational and shipping business to be in danger situation. The fuel consumption of a ship is influenced by ship volume or wetted area which contributes directly to the increase of ship resistance and the size of main engine. In order to find out the appropriate answers, a series of investigation into river transportation using monohull, catamaran and trimaran types of vessel was carried out. The work focused on the estimation of total resistance and powering as well as seakeeping characteristics and carried out experimentally using tank test and numerically using a ship design software (Maxsurf). It was found out that the catamaran and trimaran could have less resistance and hence power compared to monohull of similar displacement. The seakeeping characteristics of the multihull vessels were also comparable with those of the monohull. This is a good indication that river catamaran/trimaran is an efficient and comfortable vessel. If a prototype or real vessel is developed, it can be a very efficient ship as well as a ship with high safety standard.

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Kemampuan proses produksi yang dihubungkan dengan state-of-the-art teknologi memungkinkan pembangunan kapal yang disesuaikan dengan peralatan mutakhir akan berdampak pada tingkat produktivitas dan daya saing. Studi ini mengusulkan pendekatan regresi nonparametrik splin kubik dengan 1 knot, 2 knot, dan 3 knot. Aplikasi program Tibco Spotfire S+ menunjukkan bahwa splin kubik dengan 2 knot (4,25 dan 4,50) memberikan hasil terbaik dengan nilai general cross validation (GCV) = 56,21556 dan R2 = 94,03%. Hasil estimasi splin kubik dengan 2 knot untuk PT. Batamec Shipyard = 35,61 MH/CGT, PT. Dok & Perkapalan Surabaya = 27,49 MH/CGT, PT. Karimun Sembawang Shipyard = 27,49 MH/CGT, dan PT. PAL Indonesia = 19,89 MH/CGT.

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Abstract
Ability of production processes associated with state-of-the-art technology, which allows the shipbuilding, is customized with modern equipment. It will give impact to level of productivity and competitiveness. This study proposes a nonparametric regression cubic spline approach with 1 knot, 2 knots, and 3 knots. The application programs Tibco Spotfire S+ showed that a cubic spline with 2 knots (4 .25 and 4.50) gave the best result with the value of GCV = 56.21556, and R 2= 94.03%.Estimation result of cubic spline with 2 knots for the PT. Batamec shipyard = 35.61MH/CGT, PT. Dok & Perkapalan Surabaya = 27.49 MH/CGT, PT. Karimun Sembawang Shipyard = 27.49 MH/CGT, and PT. PAL Indonesia = 19.89 MH/CGT.