Judul: Tata Niaga dan Pendugaan Volume Perdagangan Ilegal Trenggiling (Manis javanica Desmarest 1822)
Abstrak: Perburuan dan perdagangan ilegal trenggiling menyebabkan penurunan populasi trenggiling di alam dan menyebabkan negara mengalami kerugian secara ekologi dan ekonomi. Penelitian ini bertujuan untuk mengidentifikasi alur tata niaga, karakteristik pelaku, serta menduga volume dan nilai perdagangan ilegal trenggiling. Metode yang digunakan yaitu wawancara dengan staf BKSDA Jawa tengah dan BKSDA Yogyakarta, dan studi literatur. Data yang digunakan yaitu data operasi perdagangan satwa liar ilegal tahun 2015-2020 dari Ditjen GAKKUM-KLHK, GAKKUM Sumatera, BKSDA Yogyakarta, BKSDA Jawa Tengah, dan penelusuran dokumen melalui SIPP MA. Data dianalisis menggunakan deskriptif kualitatif dan kuantitatif. Hasil penelitian mengidentifikasi 5 jenis alur tata niaga ilegal yang didominasi oleh jenis alur restricted access 49% dan multiple barriers to market 25%. Alur tata niaga melibatkan warga lokal, bersifat tertutup dan kompleks. Pelaku merupakan usia produktif dan didominasi oleh laki-laki. Pemburu cenderung memiliki mata pencaharian sebagai buruh dan perantara sebagai pedagang. Bagian yang dijual dari trenggiling yaitu trenggiling utuh, sisik dan dagingnya dengan volume perdagangan ilegal trenggiling periode 2015-2020 sejumlah 4100 ekor dan nilai perdagangannya sebesar Rp6.032.202.989,00., Poaching and illegal trade in sunda pangolins cause a decline in population in the wild and detrimental to the country ecologically and economically. This study aims to identify the flow of commerce system, perpetrator’s characteristics, and to estimate the volume and value of illegal trade pangolins. The method used was an interview with the staff of BKSDA Central Java, BKSDA Yogyakarta, and literature studies. Used are data on illegal wildlife trade operations in 2015-2020 from the Directorate General of GAKKUM-KLHK, GAKKUM Sumatra, BKSDA Yogyakarta, BKSDA Central Java, document search through SIPP MA. Data analysis using qualitative and quantitative descriptive. There were 5 types of illegal pangolin commerce systems which were dominated by 49% restricted access and 25% multiple barriers to market. The flow of commerce system involves residents, is closed and complex. Perpetrators are productive age, dominated by men. Hunters tend to have a livelihood as laborers and intermediaries as traders. The parts that are sold from pangolins are whole pangolins, scales, and meat. The illegal trade volume of pangolins for the 2015-2020 period was 4100 animals and illegal trade value was IDR 6.032.202.989.
Keyword: tata niaga, trenggiling, volume perdagangan, commerce system, sunda pangolin, trading volume

Judul: Trading System and Estimating Illegal Trade Volume of Pig-nosed Turtles (Carettochelys insculpta Ramsay 1886)
Abstrak: Praktik perdagangan ilegal satwa liar menyebabkan kerugian secara ekologi dan ekonomi bagi negara. Penelitian ini bertujuan untuk mengidentifikasi alur tata niaga, karakteristik pelaku, dan menduga volume serta nilai perdagangan kura-kura moncong babi. Metode pengumpulan data melalui wawancara dengan pihak KLHK, BKSDA, dan bea cukai. Data transaksi perdagangan pada tahun 2016-2020 diperoleh dari putusan pengadilan negeri dan penelitian terdahulu yang dianalisis secara deskriptif kualitatif dan kuantitatif. Hasil penelitian menunjukkan terdapat empat alur tata niaga yaitu harvester directly to consumer, market space restricted, gatekeeper, dan redundant channels. Peran pelaku perdagangan sebanyak 20 orang yang terdiri dari satu pemburu, 18 perantara, dan satu konsumen. Pendugaan volume perdagangan ilegal kura-kura moncong babi pada tahun 2016-2020 sebanyak 19.064 ekor dari 16 transaksi perdagangan. Total nilai perdagangan kura-kura moncong babi pada tahun 2016-2020 sebesar Rp492.530.000,00 – Rp493.780.000,00., The practice of illegal wildlife trade causes ecological and economic losses for the country. This study aims to identify the flow of the trade system, the characteristics of the actors, estimate the volume and value of trade in pig-nosed turtles. The method of collecting data is through interviews with the KLHK, BKSDA, and custom duty. Trade transaction data in 2016-2020 were obtained from district court decisions and previous research which were analyzed descriptively qualitatively and quantitatively. The results of the study show that there are four channels of illegal trade, harvester directly to consumer, market space restricted, gatekeeper, and redundant channels. The role of the trader is 20 people consisting of one harvester, 18 intermediaries, and one consumer. The estimated volume of illegal trade in pig-nosed turtles in 2016-2020 was 19,064 from 16 trade transactions. The total trade value of pig-nosed turtles in 2016-2020 is Rp.492,530,000.00 – Rp.493,780,000.00.
Keyword: illegal, pig-nosed turtle, trade, wildlife

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.
Keyword: