Judul: Uji Kinerja Pemanfaatan Membran Reverse Osmosis pada Mesin Pendingin Absorpsi LiBr-H20
Abstrak: Absorption refrigeration system LiBr-H2O is an alternative refrigeration system to substitute vapor-compression refrigeration system, which has negative impact to environment and using mechanical energy for its operation. However, the absoption refrigeration system still needs thermal energy to regenerate the refrigerant from its absorber. The purposes of this study is to study the performance of reverse osmosis membrane to regenerate refrigerant H2O from the LiBr-H2O in absorption refrigeration system and to calculate the COP of the system. The experiment was conducted intermittently, where regeneration and refrigeration process occured separately. The study uses 3 level of LiBr-H2O concentration, namely 30%, 25%, and 20% with a variety of pressure treatments. The result of this research shows that COP of the system at concentration of 30% was 0.130 – 0.270, at concentration of 25% was 0.035 – 0.055, and at concentration of 20% was 0.015 – 0.020
Keyword: 

Judul: Exergy Analysis of Membrane Utilization for Solution Separation in LiBr-H2O Absorbtion Refrigeration System
Abstrak: Absorbtion refrigeration system provides prominent advantages in tems of environmental impact and energy consumption. Absorbtion refrigeration system uses natural refrigerant, such as water, which gives no harm to the environment. In terms of energy consumption, it requires heat to regenerate refrigerant from its absorber and provide the refrigeration effect. This form of energy is preferred since heat can be supplied from various sources, including waste heat and renewable energy, and thermodynamically categorized as low quality energy. However, effectiveness of refrigerant regeneration could only be obtained if the temperature is high enough. In this study, the heat utilization in the regeneration process will be eliminated by introducing membranes for separating the refrigerant from the absorber. Specifically, the objectives of this research are to :1) to study the absorbtion mechanism of water vapor by LiBr-H2O solution in a controlled condition, 2) to study the regeneration process of LiBr-H2O using reverse osmosis (RO) membrane and vacuum membrane distillation (VMD) when applied in LiBr-H2O absorbtion refrigeration system, 3) to perform the energy and exergy analysis in LiBr-H2O absorbtion refrigeration system using RO membrane. The membrane was used as a tool to separate the refrigerant from absorbent which performs as regeneration process in conventional absorbtion system. As separation component, RO membrane employs pressure to oppose the osmotic pressure and pass certain component through the pores. While, VMD employs vacuum pressure and thermal, so that the substance to be transported through the membrane is in form of vapor. The result shows that absorbtion rate of water vapor by LiBr-H2O solution was influenced by solution concentration, temperature, humidity and pressure. The highest absorbtion rate was 0.031 g/minute which was occurred at temperature 40°C, RH 70% and solution concentration 60%. Prediction model was developed to calculate the absorbtion parameter inspite of P-T-X diagram.The highest water vapor absorbtion in absorber using spiral wound module-based RO membrane occurred at initial concentration of 30%, wich is the highest concentration used in the experiment. Increasing of operation pressure during separation process will increase permeation flux but decrease rejection factor.Unexpectedly, permeate of the RO membrane still contain LiBr at concentration 7w/w %-9w/w%, which affect the achievable cooling temperature and cooling capacity. Optimization of regeneration using VMD was conducted with response surface methodology (RSM) and the result show that highest permeate flux (0.93 kg.m-2.s-1) can be achived at initial concentration of 47.5%, temperature of 80°C and flow rate of 1.9 L.min-1.COP obtained in absorbtion refrigeration system using RO membran with initial concentration 20% was in the range of 1.147-1.171. Exergy analysis shows that increasing pressure of RO membrane at concentration 20% increased the irreversibity.On the other hand, exergy analysis on VMD shows that higher concentration and temperature will increased irreversibility.
Keyword: refrigeration, absorbtion, reverse osmosis, vacuum membrane distillation, energy, exergy

Judul: Karakteristik Anatomi Skelet Tubuh Badak Jawa (Rhinoceros Sondaicus).
Abstrak: Badak jawa (Rhinoceros sondaicus) merupakan spesies mamalia besar di dunia yang paling terancam punah dan hanya dapat ditemukan di Taman Nasional Ujung Kulon (TNUK), Provinsi Banten, Indonesia. Tujuan dari penelitian ini adalah mempelajari karakteristik spesifik anatomi skelet tubuh badak jawa. Struktur skelet ini dikaitkan dengan fungsinya untuk menunjang ukuran tubuh yang besar dan perilakunya. Penelitian ini menggunakan satu set preparat skelet tubuh badak jawa. Parameter penelitian yang dilakukan adalah mengamati bentuk bagian skelet yang khas, mengukur panjang dan lebar tulang, serta dibandingkan dengan skelet tubuh badak sumatra dan hewan piara lain. Kemudian, sistem penamaan pada setiap bagian tulang dilakukan berdasarkan Nomina Anatomica Veterinaria (ICVGAN 2012). Karakteristik anatomi skelet tubuh badak jawa relatif mirip pada badak sumatera, tetapi memiliki ukuran yang lebih besar. Terdapat beberapa perbedaan yang ditemukan yaitu, ala atlantis lebih panjang, processus spinosus os axis berbentuk segiempat, processus transversus et spinosus tulang leher lebih subur, processus spinosus os vertebrae thoracicae relatif lebih mengarah ke kaudodorsal terutama pada sembilan ossa vertebrae thoracicae di kranial, daerah flank lebih sempit, dan ossa sacrales yang tersusun lebih kompak dan rigid. Secara umum skelet tubuh badak jawa memiliki hubungan yang sangat erat, kokoh, dan kompak, disertai penjuluran-penjuluran dan aspek kasar sebagai tempat melekatnya otot-otot dan ligamenta dengan kuat. Hal ini berperan dalam mempertahankan rigiditas dan menjaga sikap tubuh badak jawa terkait dengan habitat dan perilakunya.
Keyword: anatomi, badak jawa, skelet tubuh