Judul: Desorpsi timbal pada kerang darah (Anadara granosa) menggunakan ekstrak air kulit jeruk siam dan pektinnya
Abstrak: Kerang darah (Anadara granosa) dari beberapa perairan dilaporkan memiliki kadar timbal (Pb) di atas ambang batas yang ditetapkan oleh Standar Nasional Indonesia (SNI). Pada penelitian ini, kadar Pb dalam kerang darah dikurangi menggunakan ekstrak air kulit jeruk siam dan pektinnya. Ekstrak air diperoleh dengan menghancurkan kulit jeruk siam yang ditambahkan air (1:3). Rektin diekstraksi menggunakan HCl 0.1 N pada pH 1.5, suhu 95 °C selama 40 menit. Rendemen pektin yang dihasilkan 10.18%, bobot ekivalen 1180.45 g/ek, Kadar metoksil 6.52% (b/b), kadar asam galakturonat 57.65% (b/b), dan derajat Sterifikasi 64.24% (b/b). Sampel kerang darah yang diambil dari Pasar Anyar Bogor memiliki kadar Pb di bawah ambang batas SNI. Daging kerang darah direndam dalam larutan Pb agar kadar Pb sebelum dan sesudah desorpsi dapat diukur. Proses desorpsi dilakukan dengan merendam daging kerang dalam ekstrak air kulit jeruk siam dan dalam larutan pektin 0.2% selama 60 menit. Ekstrak air kulit jeruk siam menurunkan kadar Pb sebesar 46%, sedangkan larutan pektin menurunkan kadar Pb sebesar 48%...
Keyword: Anadara granosa, Desoption, Lead, Pectin, Siam orange peel

Judul: Desorpsi Timbal pada Kerang Darah (Anadara granosa) Menggunakan Ekstrak Air Kulit Jeruk Siam dan Pektinnya
Abstrak: Blood cockles (Anadara granosa) from some sources were reported to contain lead above the threshold as defined by the Standar Nasional Indonesia (SNI). In this experiment, orange peel extract and its pectin were used to reduce the lead content on blood cockles. Aqueous extract orange peels were obtained by crushing the peels and mixed with in proportion of 1:3. Pectin was extracted from the peels using HCl 0.1 N at pH 1.5, and temperature 95 °C for 40 minutes. The pectin yield was 10.18%, equivalent weight 1180.45 g/eq, methoxyl content 6.52% (w/w), galacturonic acid 57.65% (w/w), and degree of estherification 64.24% (w/w). Samples of blood cockles purchased from Pasar Anyar Bogor. The result showed that lead content was below SNI threshold. The samples of blood cockle meat were soaked in lead solution and desorption of lead could be measured. Desorption process were performed by soaking the samples in the extract solution and in 0.2% pectin solution for 60 minutes. The aqueous extract of orange peel reduced lead content by 46%, whereas pectin solution was able to reduced for 48%.
Keyword: Anadara granosa, desorption, lead, pectin, siam orange peel

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm