Judul: Hubungan Panjang-Berat Stichopus Ocellatus (Holothuroidea) Di Kepulauan Seribu, Jakarta
Abstrak: Stichopus ocellatus merupakan teripang ekonomis penting yang ada di Indonesia maupun dunia. Data mengenai spesies ini belum banyak dieksplorasi. Tujuan dari penelitian ini adalah untuk menganalisis hubungan panjang-berat dan keragaman genetik dari Stichopus ocellatus. Metode yang digunakan adalah DNA Barcoding dengan marka mitokondria lokus CO1. Pohon filogenetik dan jarak genetik menunjukkan adanya sedikit perbedaan urutan basa antar individu. Komposisi basa nukleotida Adenin (A) dan Timin (T) lebih banyak dibandingkan Sianin (C) dan Guanin (G). Hal ini berkaitan dengan ikatan hidrogen yang mengikat basa tersebut. Kemungkinan terjadinya transisi lebih besar dari transversi karena berkaitan dengan karakteristik dari purin dan pirimidin. Hubungan panjang-berat menunjukkan pola pertumbuhan allometrik negatif yaitu pertumbuhan panjang lebih dominan dibandingkan pertumbuhan berat. Keragaman genetik termasuk dalam kategori tinggi berdasarkan nilai keragaman haplotipe (0.8498 ± 0.0521) dan keragaman nukleotida (0.0074 ± 0.0042).
Keyword: teripang, DNA Barcoding, hubungan panjang-berat, keragaman genetik, coral triangle

Judul: Identifikasi molekuler dan keragaman genetik spons invasif Terpios hoshinota di Pulau Dapur, Kepulauan Seribu
Abstrak: Terpios hoshinota merupakan salah satu spesies spons invasif yang menyebarluas di perairan Indo-Pasifik. Penyebaran Terpios hoshinota di Indonesia telah ditemukan di Kepulauan Spermonde dan Kepulauan Seribu. Namun demikian, spons mempunyai keanekaragaman spesies yang tinggi tetapi dikenal sebagai organisme yang sulit diidentifikasi secara morfologi. Penelitian ini bertujuan mengidentifikasi Terpios hoshinota secara genetik, menganalisis keragaman genetik serta merekonstruksi pohon filogenetik Terpios hoshinota di Pulau Dapur, Kepulauan Seribu. Amplifikasi DNA dengan gen CO1 mengidentifikasi Terpios hoshinota dengan tingkat kemiripan 95 % - 99 %. Rata-rata panjang nukleotida 679 basepairs, rata-rata komposisi timin (T)= 37 %; sitosin (C)= 18.6 %; adenin (A)= 23 % dan guanin (G)= 21.4 %. Keragaman genetiknya yaitu 0.0962 (keragaman haplotiope) dan 0.4412 ± 0.2574 (keragaman nukleotida). Hasil analisis filogenetik menggunakan model Neighbor Joining Treedengan model substitusi Kimura 2-parameter menunjukkan 6 individu sampel Terpios hoshinota di Pulau Dapur mempunyai kekerabatan yang dekat.
Keyword: identification, molecular, DNA Barcoding, Terpios hoshinota

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