Judul: Kandungan Logam Berat (Hg, Cd, Pb, dan Cu) pada Ikan Baronang Siganus javus (Linnaeus, 1766) di Perairan Teluk Banten dan Sekitarnya
Abstrak: Kegiatan antropogenik dapat memberikan masukan limbah berupa logam berat sehingga konsentrasinya di perairan meningkat dan menyebabkan akumulasi, khususnya pada ikan baronang. Penelitian ini bertujuan menduga tingkat akumulasi kandungan logam berat (Hg, Cd, Pb, dan Cu) pada daging ikan baronang (Siganus javus) di perairan Teluk Banten dan sekitarnya. Pengambilan 30 g hingga 50 g sampel daging ikan dilakukan setiap bulan dari bulan Agustus hingga Oktober 2020 dan analisis kandungan logam berat (Hg, Cd, Pb, dan Cu) pada daging ikan baronang dilakukan pada Februari 2021 menggunakan metode atomic absorption spectrophotometry (AAS). Kandungan logam berat Hg, Cd, dan Pb pada daging ikan baronang berada di bawah batas deteksi AAS, sedangkan kandungan logam berat Cu pada daging ikan kecil berkisar 0,348 mg kg-1 hingga 1,530 mg kg-1 dan ikan besar kurang dari 0,015 mg kg-1 hingga 5,390 mg kg-1. Bioakumulasi logam Cu pada ikan baronang ukuran kecil dan besar termasuk akumulasi rendah hingga tinggi sedangkan untuk jenis logam lainnya termasuk akumulasi rendah. Batas aman konsumsi daging ikan baronang untuk orang dewasa (50 kg) yaitu 32,468 kg daging/minggu sedangkan untuk anak-anak (15 kg) sebanyak 9,740 kg daging/minggu., Anthropogenic activities contribute heavy metals so that their concentration in the waters increases and causes accumulation, especially in streaked spinefoot. This study aims to estimate the level of accumulation of heavy content (Hg, Cd, Pb, and Cu) in the meat of streaked spinefoot (Siganus javus) in the waters of Banten Bay and its surroundings. Sampling of 30 to 50 grams of fish meat is carried out every month from August to October 2020 and analysis of heavy metal content (Hg, Cd, Pb, and Cu) in streaked spinefoot meat was carried out in February 2021 using atomic absorption spectrophotometry (AAS). The content of heavy metals Hg, Cd, Pb in the meat of streaked spinefoot is below the detection limit AAS, while the content of heavy metal Cu in the small fish ranged from 0.348 to 1.530 mg kg-1 and large fish is less than 0.015 mg kg-1 to 5.390 mg kg-1. Bioaccumulation of Cu metal in small and large streaked spinefoot included low to high accumulation, while for other types of metal it was low. The safe limit for consumption of streaked spinefoot meat for adults (50 kg) is 32.468 kg of meat/week, while for children (15 kg) it is 9.740 kg of meat/week.
Keyword: Akumulasi, Ikan baronang, logam berat, Teluk Banten, Accumulation, Banten Bay, heavy metals, Streaked spinefoot

Judul: Kandungan Logam Berat Hg, Cd, Pb, dan Cu pada Ikan Bandeng Chanos chanos (Forsskal, 1775) di Perairan Bojonegara, Teluk Banten
Abstrak: Perairan Bojonegara sebagai bagian dari Teluk Banten, merupakan perairan yang mendapat pengaruh dari aktivitas industri, perkapalan, dan domestik. Aktivitas tersebut dapat menimbulkan pencemaran berupa logam berat. Penelitian ini bertujuan untuk menentukan tingkat akumulasi logam berat (Hg, Cd, Pb, dan Cu) pada daging ikan bandeng serta menentukan batas aman dalam mengkonsumsi ikan bandeng (Chanos chanos) di perairan Bojonegara, Teluk Banten. Pengambilan contoh ikan dan pengamatan perairan dilaksanakan dari bulan Agustus hingga Oktober 2020. Pengukuran kandungan logam berat pada daging ikan dilakukan dengan menggunakan AAS (Atomic Absorption Spectrophotometer). Kandungan logam berat Hg, Cd, dan Pb masih berada dibawah limit deteksi alat AAS dan masih berada di bawah baku mutu. Kandungan logam Cu pada ikan bandeng ukuran besar berkisar antara 2,87- 16,87 mg/kg, sedangkan ukuran kecil berkisar antara 0,273-0,481 mg/kg. Kandungan logam Cu pada ikan bandeng ukuran kecil masih berada di bawah baku mutu, sedangkan ikan bandeng ukuran besar telah melebihi baku mutu yang telah ditetapkan. Akumulasi logam Hg, Cd, dan Pb pada ikan bandeng tergolong akumulasi rendah, sedangkan akumulasi logam Cu tergolong akumulasi rendah hingga tinggi. Kandungan logam berat Hg, Cd, Pb, dan Cu terhadap ukuran ikan besar dan kecil tidak berbeda nyata., Bojonegara waters as part of Banten Bay, are waters that are affected by industrial, shipping and domestic activities. These activities can cause pollution in the form of heavy metals. This study aims to determine the level of accumulation of heavy metal (Hg, Cd, Pb, and Cu) in milkfish meat and determine the safe limit for consuming milkfish (Chanos chanos) in Bojonegara waters. Measurement of heavy metals content in fish meat was carried out using AAS (Atomic Absorption Spectrophotometer). The content of heavy metals Hg, Cd, and Pb is still below the detection of the AAS tool and is still below the quality standard. The content of Cu metal in large milkfish ranges from 2,87-16,87 mg/kg, while the small size ranges from 0,273-0,481 mg/kg .The content of Cu metal in small milkfish is still below the quality standard, while large milkfish has exceeded the established quality standard. The accumulation of Hg, Cd, and Pb in milkfish is classified as low accumulation, while the accumulation of Cu metal is classified as low to high accumulation. The content of heavy metals Hg, Cd, Pb, and Cu on the size of the large and small fish is not significantly different.
Keyword: Banten Bay, Bojonegara waters, heavy metals

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology