Judul: Faktor-Faktor yang Memengarahui Perubahan Perilaku Owa Jawa (Hylobates moloch, Audebert 1798) di Taman Margasatwa Ragunan Jakarta
Abstrak: Javan gibbon (Hylobates moloch Audebert, 1798) is one of the animals with Endangered conservation status according to the IUCN. One of the conservation activities at the Schmutzer Primate Center, Ragunan Wildlife Park, is breeding the Javan gibbon. the Covid-19 pandemic was an event that affected the behavior of the Javan gibbon but there is no data on the behavior of the Javan gibbon after the pandemic ended. The purpose of this study was to describe the behavior of the Javan gibbon after the Covid-19 pandemic, to identify differences in the behavior of the Javan gibbon during and after the Covid-19 pandemic, as well as the factors that influenced the behavior of these animals. The research was conducted from January to March 2023 at TMR. Behavioral data collection method with instantaneous scan sampling. The results data obtained after the Covid-19 pandemic showed 3 new behaviors during the post-Covid-19 pandemic: shelter-seeking, agonistic and sex. The frequency of moving behavior after the Covid-19 pandemic had the highest percentage, while during the Covid-19 pandemic, the behavior of resting had the greatest frequency. Factors that influence the behavior of the Javan gibbon include the size of the cage, the weather, and the presence of visitors.
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Judul: Dukungan Masyarakat Lokal dan Habitat untuk Konservasi Owa jawa (Hylobates moloch, Audebert, 1798) di Resort Bodogol Taman Nasional Gunung Gede Pangrango
Abstrak: The Javan gibbon (Hylobates moloch Audebert, 1798)), found in Western Java, is one of the rarest and most endangered hylobatids. The role of local community on natural resource management and wildlife conservation in national parks, particularly in Mount Gede Pangrango (Resort Bodogol), is of vital importance. The aims of the study were to analyze the community activities conducted for the population of H. moloch, predict population growth for H. moloch and identify the use of habitat by H. moloch. The study was analyzed descriptively using data collected by questionnaires as well as field observation. Purposive Sampling technique was used to collect data from 100 respondents. The results showed that only 25% of them were active participants regarding conservation of H. moloch. The population of H. moloch consisted of 13 groups with 39 individuals which are 13 adult males and 14 adult females, 5 sub adult males, 4 sub adult females and 3 infantiles. The average population density was estimated at 27 animals/km2, the standard error of 2,61, with coefficient of variance 6,69%.The group studied was composed of one adult male, two adult female, two subs adult and one infant. The results from Focal Animal sampling method within five minutes interval showed that the time proportion of group activities consisted of feeding (33,06%), moving (10,87%), resting (36,26%), calling (4,32%) and social activities (15,45%). The value of sex ratio is 1:1,25 for sub adult, while the value of adult sex ratio was 1:0,92. Both of the sex ratio closes to 1:1. The rate of natality is 0,21, while the mortality rate cannot be calculated due to the lack of direct observation and time constraint. It is found that the diversity of plant species in habitat, consisted of 77 species from 27 families. Keywords: Javan gibbon, habitat, conservation, Bodogol
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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