Judul: Kombinasi Pretreatment Asam Perasetat dan Deep Eutectic Solvents Choline Chloride Oxalic Acid pada Residu Ulva lactuca untuk Produksi Bioetanol
Abstrak: Ulva lactuca merupakan rumput laut hijau yang dapat diekstrak menghasilkan ulvan. Residu ekstraksi ulvan berpotensi menjadi sumber bahan baku bioetanol. Deep Eutectic Solvent (DES) dan asam perasetat (PAA) adalah senyawa kimia ramah lingkungan dapat digunakan untuk residu. Penelitian ini bertujuan menentukan pengaruh suhu dan waktu kombinasi pretreatment DES dengan asam perasetat pada residu U. lactuca berdasarkan analisis, rendemen, derajat putih, gula reduksi, dan gugus fungsi. Penelitian ini dilakukan meliputi sintesis DES, preparasi bahan, ekstraksi ulvan, pretreatment DES, dan pretreatment PAA. Residu U. lactuca dengan pretreatment DES dan PAA masing-masing menghasilkan rendemen 32,92-56,55%, dan 24,64-41,73%, nilai derajat putih sebesar 44,49-57,44%, dan gula reduksi 0,80-1,20 mg/mL. Faktor suhu dan waktu memiliki pengaruh negatif pada rendemen DES dan PAA serta gula reduksi dan berpengaruh positif terhadap derajat putih. Pretreatment dapat mengurangi kadar lignin, hemiselulosa, dan selulosa dibuktikan dari bilangan gelombang 1627cm-1, 1160 cm-1, dan 1030 cm-1 sehingga potensial untuk produksi bioetanol., Ulva lactuca is a green seaweed that can be extracted to produce ulvan. While the residue from ulvan extraction holds potential as a raw material for bioethanol. Deep Eutectic Solvent (DES) and peracetic acid (PAA) are environmentally friendly chemical compounds that can be used for U. lactuca residues. These alternatives can be considered for the efficient utilization of U. lactuca residues. This studied aimed to determine the effect of temperature/time combination of DES pretreatment with PAA on residue based on analysis, yield, whiteness, reduced sugars and functional groups. This researched included DES synthesis, material preparation, ulvan extraction, DES and PAA pretreatments. U. lactuca residue with DES and PAA pretreatment produced yields of 32.92-56.55%, and 24.64-41.73%, respectively with white degree valued of 44.49-57.44%, and reduced sugar 0.80-1.20 mg/mL. Temperature and time negatively affected DES, PAA yields and reduced sugars, and positively affected whiteness. Pretreatment could decrease lignin, hemicellulose, and cellulose concentrations as prove by waved numbered of 1627cm-1, 1160 cm-1, and 1030 cm-1, made it potential for bioethanol generation.
Keyword: bioetanol, DES, PAA, residu ulvan, bioethanol, ulvan residual

Judul: Extraction of Ulvan from Seaweed Ulva lactuca Using Different Types and Concentration Deep Eutectic Solvents (DES)
Abstrak: Ulva lactuca atau biasa disebut selada laut adalah rumput laut hijau yang memiliki pertumbuhan tiga kali lebih cepat dibanding dengan jenis rumput lain dan kandungan polisakarida bersulfat tinggi yang dapat dimanfaatkan untuk aktivitas biologisnya. Deep Eutectic Solvents (DES) muncul sebagai alternatif untuk mengekstrak ulvan karena sifatnya yang biodegradable, ramah lingkungan, dan tidak berbahaya. Penelitian ini bertujuan menentukan jenis dan konsentrasi DES yang dapat menghasilkan karakteristik ekstrak ulvan terbaik berdasarkan analisis rendemen, FTIR, dan viskositas serta uji kadar air dan kadar sulfat. Tahapan penelitian yang dilakukan meliputi preparasi dan karakteristik bahan baku, sintesis DES, ekstraksi, serta analisis dan uji lanjutan. Perbedaan jenis dan konsentrasi DES berpengaruh terhadap hasil analisis. Hasil uji menunjukkan rendemen ulvan tertinggi terdapat pada perlakuan jenis DES kolin klorida-urea 30% (KKU30), sedangkan nilai kadar sulfat, dan viskositas tertinggi terdapat pada perlakuan kolin klorida-gliserol 30% (KKG30). Gugus fungsi ulvan pada perlakuan kolin klorida-gliserol 30% (KKG30) menunjukkan hasil pita serapan yang serupa dengan perlakuan HCl., Ulva lactuca commonly called sea lettuce is a green seaweed that grows three times faster than other types of grass and contains high sulfated polysaccharides which can be utilized its biological activity. Deep Eutectic Solvents (DES) have emerged as an alternative to extract ulvan because of their biodegradable, environmentally friendly, and harmless properties. This study aims to determine the type and concentration of DES which can produce the best characteristics of ulvan extract based on yield, FTIR, viscosity also tests for water content and sulphate content. DES synthesis, extraction, further analysis and testing. Different types and concentrations of DES affect the result of the analysis. The test results showed that the highest yield of ulvan was found in the type treatment choline chloride-urea 30% (KKU30), whereas the highest sulfate content, and viscosity were found in the DES treatment choline chloride-gliserol 30% (KKG30). The ulvan functional group in the treatment choline chloride-gliserol 30% (KKG30) showed similiar absorption band to the HCl treatment.
Keyword: DES, extraction, polysaccharide, Ulva lactuca, ulvan

Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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