Judul: Distribusi Logam Berat pada Kerang Hijau (Perna viridis) dari Perairan Kamal Muara, Tangerang-Jakarta
Abstrak: Shells are filter feeder animals which use gills to shift feed. This process accumulated metallic substance in the body. The nature of major heavy metal is difficult be degraded, so easy to be accumulated in aquatic environment and natural substance. The research was carried out at Laboratory of Raw Material Characteristic of Aquatic Product, Departement of Aquatic Product Technology, Faculty of Fisheries and Marine Science for preparation; metal analyses at Laboratory MIPA Bersama, Faculty of Animal Science, Bogor Agriculture University from November 2013 to January 2014. Objectives of this study is to determine the distribution of heavy metal on variety of size and body part of green mussle that are meet, gills, and viscera using Atomic absorption spectrophotometer. Result showed the highest metal in sample is Cu. Based on the size shells metal distribution on meat, gills, and the viscera were large (1.667 ± 0.104 ppm; 1.329 ± 0.05 ppm; and 1.542 ± 0.064 ppm), medium (1.517 ± 0.05 ppm; 1.427 ± 0.073 ppm; and 2.512 ± 0.05 ppm), and small (1.521 ± 0.210 ppm; 1.101 ± 0.028 ppm; and 1.655 ± 0.127 ppm).
Keyword: green shell (Perna viridis), viscera, gills, meat

Judul: Analisis Kandungan Logam Berat Hg, Cd, Pb, dan Cu pada Kerang Hijau Perna viridis (Linnaeus, 1758) di Perairan Teluk Banten
Abstrak: Teluk Banten mendapatkan masukan limbah yang menyebabkan konsentrasi logam berat di perairan meningkat dan menyebabkan akumulasi pada biota air terutama kerang-kerangan. Kerang hijau bersifat filter feeder yaitu memakan dengan cara menyaring partikel yang berada di perairan sehingga mudah mengakumulasi logam berat dalam tubuhnya. Penelitian bertujuan untuk menentukan tingkat akumulasi logam berat Hg, Cd, Pb, dan Cu pada kerang hijau (Perna viridis) dengan ukuran berbeda di Teluk Banten. Penelitian dilakukan pada bulan Agustus-Oktober 2020 di Teluk Banten. Analisis kandungan logam berat menggunakan metode Atomic Absorption Spectropotometer (AAS). Secara umum kualitas air perairan Bojonegara, Teluk Banten di bawah nilai baku mutu. Kandungan logam berat Hg, Cd, Pb, dan Cu berada di bawah baku mutu. Kerang hijau ukuran kecil dan besar mengalami bioakumulasi logam berat Cu termasuk ke dalam akumulasi tinggi, namun pada bulan Agustus kerang hijau ukuran kecil mengalami bioakumulasi sedang. Bioakumulasi logam berat Pb, Hg, Cd termasuk ke dalam akumulasi rendah. Waktu pengambilan sampel tidak berpengaruh secara signifkan terhadap kandungan logam berat Cu pada daging kerang hijau ukuran kecil dan besar., Banten Bay are continuously receiving waste input so that it is suspected that heavy metal concentrations in the waters have increased and caused accumulation in aquatic biota especially shellfish. Green mussels are filter feeder, they eat by filtering particles in the water so that they can easily accumulate heavy metals in their bodies. This study aims to determine the level of accumulation of heavy metals Hg, Cd, Pb, and Cu in green mussels (Perna viridis) of different sizes in Banten Bay. The study was conducted from August to October 2020 in Banten Bay. Analysis of heavy metals content using the Atomic Absorption Spectrophotometer (AAS) method. In general, the water quality in Bojonegara, Banten Bay is below the standard quality value. Heavy metals Hg, Cd, Pb, and Cu which are below the quality standards. Small and large green mussels size have high bioaccumulation of copper, but small green mussels in August have moderate biaccumulation. Bioaccumulation of heavy metals Hg, Cd, Pb is included in the low accumulation. Sampling time did not significantly affect the Cu heavy metal content in small and large green mussel meat.
Keyword: accumulation, Banten Bay, heavy metal, Perna viridis

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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