Judul: Sugarcane Leaf Lignin Characteristics Isolated with a Low Acid Concentration
Abstrak: Lignin daun tebu merupakan salah satu komponen biomassa yang berpotensi sebagai sumber bahan kimia alami. Sifat kimia dan metode isolasi mempengaruhi sifat bioproduk. Penelitian ini bertujuan mengkaji pengaruh metode sekeunsial pra-perlakuan daun tebu dan metode isolasi lignin terhadap rendeman isolasi lignin, sifat fisikokimia dan termal. Padatan kemudian dikarakterisasi fisikokimia dan termal (TGA dan DSC). Hasil penelitian menunjukkan kadar αselulosa pra-perlakuan asam microwave-basa autoclave lebih tinggi dibandingkan dengan pra-perlakuan asam microwave-basa microwave dengan kelarutan hingga mencapai 94%. Hasil isolasi pra-perlakuan asam microwave-basa microwave lebih tinggi dibandingkan dengan pra-perlakuan asam microwave-basa autoclave yang mencapai diatas 68%. Lignin hasil isolasi kedua proses pra-perlakuan memiliki nisbah S/G yang sama. Isolat lignin menunjukkan keberhasilan proses isolasi yang ditandai dengan adanya gugus fungsi penciri lignin dalam spektra FTIR seperti - CH, C=O dan C-O. Analisis TGA lignin masing-masing pra-pelakuan memiliki karakteristik degradasi termal yang sama. Analisis DSC menunjukkan adanya satu titik transisi glass (Tg) dengan masing-masing suhu Tg hasil pra-perlakuan asam microwave -basa microwave dan asam microwave-basa autoclave yaitu 128,44 oC dan 131,02 oC, Sugarcane leaf lignin is one of the chemical components of biomass that have prospects for natural chemicals. The chemical characteristics and the isolation method of lignin influence the bioproduct properties. The research examined the effect of the sequential pre-treatment method of sugarcane leaf and lignin isolation method on isolated lignin's yield, physicochemical and thermal characteristics. The pulp was then characterized by the chemical component and the yield, while the isolated lignin was analyzed the physicochemical and the thermal (TGA, DSC) characteristics. The results showed that the cellulose content of pretreated with acid microwave-alkaline autoclave was higher than the pre-treatment of the acid microwave-alkaline microwave with the lignin removal reached up to 94 %. The yield of isolated lignin derived from acid microwave-alkaline microwave was higher than the pre-treatment of acid microwave-alkaline autoclave, which was reached 68 %. The isolated lignin from both pre-treatment methods has the same S/G ratio. FTIR spectra indicate the functional groups of typical lignin such as -CH, C=O, and CO, indicating the isolation method's success. TGA analysis of lignin indicated that both lignins have similar thermal degradation characteristics. In contrast, DSC analysis showed a glass transition (Tg) with each Tg temperature to sugarcane trash lignin from the acid microwave-alkaline microwave and acid microwave-alkaline autoclave were 128.44 °C and 131.02 °C, respectively.
Keyword: Daun tebu, fraksionasi bertahap, iradiasi gelombang mikro, karakteristik lignin, pemanasan autoclave, autoclave heating, characteristics of lignin, gradual fractionation, microwave irradiation, sugarcane leaf

Judul: Isolasi, Karakterisasi, dan Pirolisis Lignin Pulp Soda dari Tandan Kosong Kelapa Sawit
Abstrak: Salah satu produk samping industri kelapa sawit adalah tandan kosong, yang volumenya diperkirakan mencapai 54 juta ton pada tahun 2030. Penelitian ini bertujuan mendapatkan hasil isolasi, karakterisasi, dan pirolisis lignin tandan kosong, serta mendapatkan data komponen-komponen yang muncul sebagai produk akhir pirolisis. Lignin diisolasi dengan proses pulp soda menggunakan NaOH dan dinetralkan dengan HCl serta dengan air. Hasilnya dikeringkan dan diuji kadar air, kadar abu, dan dianalisis dengan spektrometer ultraviolet dan inframerah. Sebagian sampel lignin ditambah katalis zeolit terimpregnasi ZnCl2, dianalisis menggunakan teknik termogravimetri dan kalorimetri pemayaran diferensial sebelum akhirnya diuji menggunakan alat pirolisis terintegrasi kromatografi gas-spektrometri massa. Rendemen lignin sebesar 3.4-3.6 g/100 mL lindi hitam. Produk utama pirolisis lignin adalah furfural dan tert-butil glisidil eter. Keberadaan katalis hanya sedikit memengaruhi analisis termal tetapi dapat berpengaruh besar pada komposisi senyawa hasil pirolisis.
Keyword: lignin, pirolisis, proses pulp soda, tandan kosong kelapa sawit

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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