Judul: Thermal Dispersion Modelling of Wastewater (Cooling Water) Gas and Steam Power Plant (PLTGU) in Coastal of Pemaron, Singaraja-Bali.
Abstrak: Suhu merupakan variabel yang paling penting untuk kelangsungan hidup, pertumbuhan, dan reproduksi organisme akuatik. Salah satu sumber pencemaran termal di laut berasal dari aktivitas Pembangkit Listrik Tenaga Gas dan Uap (PLTGU). Sumber daya pesisir seperti ikan dan terumbu karang berpotensi menerima dampaknya. Penelitian ini dilakukan pada bulan April 2011 hingga Oktober 2011. Pemodelan berupa simulasi model dispersi termal berbasis hidrodinamika yang dicuplik berdasarkan kondisi ekstrim pasang surut, serta pengaruh angin musim di Indonesia. Input data model pola arus adalah batimetri, angin, pasang surut, selanjutnya untuk model sebaran termal menggunakan data ambient dan gradient suhu lingkungan. Data sebaran termal yang digunakan dalam pemodelan ini merupakan hasil survei lapang tim FPIK-IPB pada tahun 2005 terkait rencana pembangunan PLTGU di perairan pantai Pemaron, Singaraja-Bali. Pada musim barat arus cenderung bergerak ke barat laut saat surut, dan ke tenggara saat pasang, dengan kisaran kecepatan antara 0,10-0,50 m/s. Pada musim timur arus cenderung bergerak ke barat saat surut, dan ke timur saat pasang, dengan kecepatan antar 0,05-0,10 m/s. Hasil pemodelan sebaran suhu air pendingin PLTGU Pemaron mengikuti pergerakan massa air laut dengan jarak sebaran maksimum pada kondisi pasang (flood). Sebaran maksimum sejauh 3,40 km musim barat dan 2,60 km musim timur ke arah timur laut dengan akibat menaikkan suhu perairan sekitar 0,25-0,50 0C di atas suhu alami. Suhu air buangan panas ketika memasuki perairan sebesar 1,28 hingga 1,35 0C lebih tinggi dari suhu alami (29 0C). Suhu mulai terlihat mendekati suhu normal ketika menyebar sejauh 400 m ke arah utara. Terumbu karang masih dapat menerima toleransi kenaikan suhu hingga 3-4 0C pada radius 1-2 km. Populasi lumba-lumba terdapat pada jarak 7,50 km dari pantai pemaron sehingga pengaruh kenaikan suhu terhadap lumba-lumba tidak terlalu signifikan.
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Judul: Thermal Dispersion Modelling of Labuan Power Plant Wastewater Discharge
Abstrak: Pembangkit Listrik Tenaga Uap (PLTU) Labuan dengan kapasitas total 600 MW berpotensi menyebarkan limbah air panas hasil proses pendinginan ke perairan pantai Labuan. Penelitian ini bertujuan untuk mengkaji pola sebaran limbah air panas serta menganalisis luas dan jarak sebaran limbah tersebut di PLTU Labuan. Sebaran limbah air panas disimulasikan melalui model dispersi termal 2-dimensi menggunakan perangkat lunak MOHID Studio 2016. Validasi model dengan data observasi diperoleh koefisien korelasi sekitar 0,922 (elevasi pasang surut), 0,071 (arus zonal), 0,114 (arus meridional), dan 0,877 (suhu air laut). Pola sebaran arus permukaan di perairan Labuan dominan bergerak menuju daratan saat kondisi pasang dan menjauhi daratan saat kondisi surut dengan kecepatan arus maksimal sekitar 0-1 ms-1. Di bagian barat domain model arus cenderung bergerak ke arah selatan-barat daya, namun di wilayah dekat dengan daratan arus cenderung bergerak ke utara-timur laut menyusuri pantai. Sebaran limbah air panas PLTU terjadi maksimum pada kondisi surut. Air buangan pada skenario normal memiliki interval suhu 30 ºC – 37,8 ºC. Pada kondisi surut, luasan limbah air panas dengan suhu >32 ºC pada skenario normal adalah 1,0475 km² dan menyebar sampai jarak 1.200 m dari titik outlet. Air buangan pada skenario maksimum memiliki interval suhu 30 ºC – 40 ºC. Pada kondisi surut, luasan limbah air panas dengan suhu >32 ºC pada skenario maksimum sekitar 1,365 km² dan menyebar sampai jarak 1.350 m dari titik outlet., Labuan Power Plant with a total capacity of 600 MW has the potential to spread thermal waste water from the cooling process to the Labuan coastal waters. This research aimed to study the distribution pattern of thermal waste water and to analyze the area and distance of the distribution of the waste at Labuan Power Plant. Thermal distribution was simulated through a 2-dimensional thermal dispersion model using MOHID Studio 2016 software. Validation of the model with observation data obtained correlation coefficients of around 0,922 (tidal elevation), 0,071 (zonal current), 0,114 (meridional current), and 0,877 (sea surface temperature). The pattern of surface currents in Labuan waters is dominantly moving towards the mainland during high tide conditions and away from the mainland during low tide conditions with maximum current velocity of around 0-1 ms-1. In the western part of the research domain, currents tend to move to south-southwest, but in areas close to the mainland, currents tend to move to north-northeast along the coast. The distribution of Power Plant thermal waste water is maximum at low tide. Wastewater in the normal scenario has a temperature interval of 30 °C - 37.8 °C. At low tide, the thermal waste water area with a temperature >32 °C in the normal scenario is around 1,0475 km² and spreads to a distance of 1.200 m from the outlet point. Wastewater in the maximum scenario has a temperature interval of 30 °C – 40 °C. At low tide, the thermal waste water area with a temperature >32 °C in the maximum scenario is around 1,365 km² and spreads to a distance of 1.350 m from the outlet point.
Keyword: limbah air panas, model dispersi termal, PLTU Labuan, sistem MOHID, Labuan Power Plant, MOHID system, thermal dispersion model, thermal waste water

Judul: Categorization in Macaca fascicularis.
Abstrak: Categorization is an ability to group individuals or events into different classes mediated by conceptualized mental images. There are several levels of categorization and within a taxonomy the levels are nested. At the most concrete level of categorization, all or most members of the category shared common physical attributes that differ from other categories. The higher the level of category, the fewer common attributes between members of the group. In addition to humans, the ability to categorize has also been proposed in animals. One example of categorization in animal is species discrimination. Using matching-tosample task, present experiment tested ability of the long-tailed macaque (Macaca fascicularis) in discriminating dichotomous-stimuli of different animals. The species has been shown to be able to see photos as representations of real object so I used facial photos of humans and animals for the stimuli. First, I tested their ability to classify humans and macaques into separate group. Second, I tested their ability to discriminate their conspecific from other macaques. And the last, I tested whether the subjects were able to discriminate non-human animals from humans. In all of these experiments I found that the subjects showed high performance in categorizing objects, even when I discarded details of visual informations, such as color and local shapes. The ability to identify objects with reduced representation of physical properties means the subjects were able to generalize attributes of members of the group. This would indicate that the subjects created a higher level abstraction. On the other hand, in discriminating intrageneric macaque species I found that they were able to extract uniqueness of each species. More over, I also found that the subjects were able to put photos of non-human animals that shared very few similarities in physical percepts into one group. I suggested that the subjects could create a more abstract concept based on non-percepts relations as a basis to put the objects into one category. Thus, I concluded that M. fascicularis were able to perform multiple levels of categorizations.
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