Judul: Penggunaan Metode Perturbasi Homotopi untuk Menyelesaikan Persamaan Burgers dan Penerapannya pada Masalah Arus Lalu Lintas
Abstrak: Traffic flow problems are frequently referred as problems of congestion, accidents and traffic violations. Traffic accidents often occur because the vehicle drivers can not control the speed of their vehicle. One of the efforts that must be made by the vehicle drivers to control the speed of their vehicle is driving under the road speed limit. On this traffic flow problems, the road speed limit will be assessed based on the Burgers equation. The Burgers equation can be solved by the homotopy perturbation methods. The results of the homotopy perturbation method will be compared to the results of numerical methods.
Keyword: traffic flow problems, homotopy perturbation method, Burgers equation

Judul: Implementasi Penyelesaian Persamaan Burgers dengan Metode Beda Hingga dalam Bahasa Pemrograman Julia
Abstrak: Persamaan Burgers merupakan salah satu persamaan diferensial parsial yang digunakan untuk memodelkan beberapa kejadian yang berkaitan dengan fluida. Karya ilmiah ini membahas tentang penyelesaian persamaan Burgers dengan metode beda hingga. Dalam karya ilmiah ini, telah diketahui beberapa parameter bagi persamaan Burgers dan digunakan beberapa kasus partisi dalam metode beda hingga. Berdasarkan hasil yang diperoleh dapat diketahui bahwa semakin banyak partisi yang digunakan maka hasil numerik yang didapatkan akan semakin mendekati hasil eksaknya. Pada karya ilmiah ini, perhitungan secara numerik dilakukan dengan bantuan bahasa pemrograman Julia., Burgers equation is one of the partial differential equations used to modelling several events related to fluids. This study discusses solving burgers equations with the finite difference method. Several parameters have been known for the Burgers equation and several cases of partitions are used in finite difference methods. Based on the result obtained, it can be seen that the more partitions used, the numerical result obtained will be closer to the exact result. In this study, calculations are numerically carried out with the help of Julia programming language.
Keyword: Julia, metode beda hingga, persamaan diferensial parsial, persamaan Burgers, Burgers equation, finite difference method, partial differential equation

Judul: Phycocyanin Extract From Spirulina platensis for as an Antioxidant and Biopigment for Spherificated Caviar Product
Abstrak: Fikosianin merupakan pigmen alami berwarna biru cerah yang kaya manfaat dengan kandungan antioksidan yang tinggi. Antioksidan memiliki peran yang sangat penting untuk mencegah kerusakan tubuh pada level molekuler yang disebabkan oleh radikal bebas. Radikal bebas dapat mengakibatkan kerusakan DNA, pembelahan sel abnormal (kanker), penuaan dini, inflamasi, penyakit jantung, dan beragam efek negatif lainnya. Pigmen fikosianin tersedia secara melimpah pada Spirulina platensis yang merupakan ganggang hijau biru (mikroalga) yang mudah dikultivasi dan dikondisikan serta dapat tersedia sepanjang tahun. Sebagai pigmen alami, fikosianin cenderung tidak stabil terpapar oksigen, cahaya, suhu, dan pH tertentu. Pemanfaatan pigmen fikosianin harus mampu menjaga kestabilan kandungan bioaktif pigmen dan tetap menarik bagi konsumen. Pengolahan pigmen fikosianin sebagai food additive pewarna pada produk spherificated caviar dapat dilakukan. Spherificated caviar dibuat dengan teknik spherification yang berfungsi sebagai penyalut yang melindungi bahan inti. Tujuan dari penelitian yaitu mempelajari pengaruh penambahan pigmen fikosianin kedalam produk spherificated caviar terhadap stabilitas kandungan antioksidan pigmen serta penerimaan konsumen terhadap produk. Metode yang dilakukan meliputi ekstraksi pigmen fikosianin dengan metode maserasi, kemurnian pigmen, analisis aktivitas antioksidan, dan uji organoleptik. Hasil menunjukan ekstrak pigmen dalam jangkauan warna biru kehijauan, pemurnian ekstrak menghasilkan angka 1,541 dengan kategori food grade. Analisis antioksidan menghasilkan nilai IC50 2,81 untuk ekstrak, dan nilai IC50 10,54 setelah diolah menjadi produk, keduanya termasuk kedalam kategori antioksidan kuat. Variasi konsentrasi pigmen fikosianin tidak memberi perbedaan nyata terhadap penerimaan konsumen dalam atribut warna, rasa, dan tekstur produk. Kata kunci: antioksidan, fikosianin, pigmen, spherificated caviar, Spirulina platensis, Phycocyanin is a bright blue natural pigment that has great beneficial and rich in antioxidant content. Antioxidant has an important role in preventing molecular damage on the body that is caused by free radicals. Free radicals could cause DNA damage, abnormal cell growth (cancer), premature aging, inflammation, heart diseases, and other negative effects. Phycocyanin pigment is found abundance in Spirulina platensis which is a blue green algae (microalgae) that is easy to cultivated and conditioned, also able to produce throughout the year. As a natural pigment, phycocyanin is prone to be unstable when exposed to oxygen, light, and to a certain temperature and pH. The utilization of phycocyanin pigment as colorant food additive in spherificated caviar product could be considered. Spherificated caviar is made with spherification technique that acts as coat / encapsulating that protects the main substance. The objective of this research is to study the effect of adding phycocyanin pigment into spherificated caviar product and also consumer preference of the product. Methods that are used including phycocyanin extractions with maceration method, phycocyanin pigment purity ratio, antioxidant activity analysis, and organoleptic test. The result shows phycocyanin pigment extraction produce bluish green colour, phycocyanin purification resulting in 1,541 value which belongs in the food grade category. Antioxidant analysis resulting in IC50 value of 2, 81 for phycocyanin extract, and IC50 value of 10,54 after being processed into spherificated caviar product, both value fall under very strong antioxidant category. Variants of phycocyanin pigment concentration added into the product did not affect consumer preferences in color, taste, and texture of the product. Keywords: antioxidant, phycocyanin, pigment, spherificate caviar, Spirulina platensis
Keyword: antioxidant, phycocyanin, pigment, spherificated caviar, spirulina platensis