Judul: Kelimpahan Mikroplastik pada Sedimen di Muara Sungai Citarum, Bekasi, Jawa Barat
Abstrak: Lingkungan perairan yang baik sangat penting bagi kehidupan biota perairan. Kerusakan lingkungan perairan akan memiliki dampak terhadap lingkungan perairan dan biota. Sampah plastik yang terdiri dari makroplastik dan mikroplastik merupakan salah satu sumber kerusakan lingkungan perairan. Mikroplastik di sedimen dapat berdampak negatif bagi biota perairan dan rantai makanan. Tujuan penelitian ini untuk mendeskripsikan sebaran dan kelimpahan mikroplastik pada sedimen. Pengambilan contoh dilakukan di Desa Pantai Bahagia, Muara Gembong, Sungai Citarum, Kabupaten Bekasi, Jawa Barat pada bulan Oktober dan Desember 2018. Pada penelitian ini dilakukan dua analisis, yaitu analisis kelimpahan mikroplastik dan FT-IR. Uji statistik yang digunakan yaitu Kruskal Wallis dan Mann Whitney. Hasil yang ditemukan paling dominan mikroplastik dengan tipe fiber dan hal ini menunjukkan mikroplastik lebih banyak berasal dari monofilamen jaring ikan, tali, dan kain sintesis. Kelimpahan mikroplastik paling tinggi ditemukan di stasiun yang paling dekat dengan laut, sebaran mikroplastik semakin mendekati laut kelimpahannya semakin tinggi.
Keyword: biota perairan, mikroplastik, sedimen

Judul: Kelimpahan Makroplastik dan Mikroplastik pada Sedimen di Muara Sungai Cisadane, Kabupaten Tangerang
Abstrak: Plastik merupakan jenis sampah yang paling dominan tersebar di perairan. Muara sungai merupakan bagian sungai yang paling besar menerima bahan pencemar. Sampah plastik yang berukuran makro dan mikro tersebar di permukaan dan sedimen dasar perairan, sehingga menyebabkan ketidakstabilan ekologi dan menurunkan kualitas lingkungan perairan. Penelitian bertujuan menganalisis kelimpahan makroplastik, kelimpahan mikroplastik berdasarkan tipe, warna, ukuran, dan jenis polimer pada sedimen di muara Sungai Cisadane. Pengambilan contoh dilaksanakan pada Juli-November 2018 di tiga titik muara Sungai Cisadane, Kabupaten Tangerang. Contoh mikroplastik dihitung dan diamati berdasarkan tipe, warna, ukuran, dan jenis polimer. Analisis jenis polimer dilakukan dengan menggunakan FTIR. Potongan plastik merupakan jenis makroplastik yang paling banyak ditemukan. Nilai kelimpahan mikroplastik berkisar 17448-23086 partikel kg-1 sedimen kering. Kelimpahan mikroplastik didominasi oleh tipe film berwarna hitam dan putih. Adapun ukuran mikroplastik paling banyak ditemukan pada ukuran 1 (20-40 μm) untuk tipe film dan fragmen, sedangkan tipe fiber dominan pada ukuran 14 (1000-2000 μm). Jenis polimer yang ditemukan yaitu polystyrene, acrylonitrile butadiene, polypropylene, low-density polyethylene, high-density polyethylen, latex, dan nylon. Jumlah potongan plastik paling banyak ditemukan di daerah intertidal pada bulan Juli. Kelimpahan tertinggi mikroplastik terdapat pada daerah muara di bulan November. Secara keseluruhan, kelimpahan mikroplastik didominasi oleh tipe film, kelompok warna hitam dan putih, serta kelompok ukuran 1 dan 14.
Keyword: makroplastik, mikroplastik, muara sungai, pengelolaan, polimer

Judul: Algorithm Construction of HLI Hash Function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice