Judul: Pengaruh Zat Ekstraktif Kayu Manglid (Magnolia Sumatrana Miq.) terhadap Nilai Kalor Batang Sawit
Abstrak: Zat ekstraktif merupakan komponen kimia dalam kayu yang mudah dilarutkan menggunakan pelarut polar, maupun nonpolar. Walaupun secara kuantitatif kandungan zat ekstraktif relatif kecil tetapi mempunyai peranan yang penting terhadap sifat kayu dan pengolahanya, salah satunya adalah meningkatkan nilai kalor kayu. Penelitian ini bertujuan untuk mengetahui pengaruh zat ekstraktif kayu manglid terhadap peningkatan nilai kalor biomassa sawit. Serbuk kayu manglid dimaserasi dengan menggunakan pelarut dengan polaritas yang berbeda yaitu n-heksana, etil eter, etil asetat, dan aseton. Selanjutnya masing-masing fraksi yang dihasilkan ditambahkan ke biomassa sawit dengan konsentrasi 0%, 2%, 4%, 6%, dan 8%, dan diukur nilai kalornya. Hasil penelitian menunjukan bahwa kadar ekstraktif yang dihasilkan bervariasi antara 0,27% - 0,99%, sedangkan nilai kalor yang dihasilkan 3580 – 3971 kkal/kg. Hasil analisis proksimat menghasilkan kadar air 11,27% - 15,59%, kadar abu 2,48% - 3,08, kadar zat terbang 78,08% - 80,16%, dan kadar karbon terikat 16,92% - 18,79%. Dari penelitian ini dapat disimpulkan bahwa penambahan fraksi n-heksana meningkatkan nilai kalor biomassa sawit tertinggi. Wood extractive substances are chemical components that can be easily dissolved using polar and nonpolar compounds. Although the quantity of extractives is relatively small, it has an important role in the properties of wood and its processing, one of which is increasing the calorific value of wood. The objectives of this study is to analyze the effect of manglid wood extractives to increase caloric value on oil palm biomass. Manglid wood was macerated using n-hexane, ethyl ether, ethyl acetate, and acetone as solvents with different polarities. Furthermore, each fraction was added to the oil palm biomass with concentrations of 0%, 2%, 4%, 6%, and 8% and the calorific value was measured. The results show that the extractive content produced varied between 0.27% - 0.99%, while the calorific value is 3580 - 3971 kcal/kg. Proximate analysis show that moisture content range from 11.27% to 15.59%, ash content range from 2.48% to 3.08%, volatile matter content range from 78.08 to 80.16%, and bound carbon content range from 16.92% to 18 ,79%. From this study, it is concluded that the addition of the n-hexane fraction increased the calorific value of the oil palm biomass.
Keyword: oil palm biomass, oil palm biomass, caloric value, wood extractive, manglid wood, proximate analysis

Judul: Zat Ekstraktif dan Pengaruhnya terhadap Nilai Kalor
Abstrak: Zat ekstraktif merupakan salah satu komponen kimia penyusun kayu yang berpengaruh terhadap nilai kalor kayu. Penelitian ini bertujuan untuk menguji pengaruh penambahan zat ekstraktif dari lima jenis kayu terhadap nilai kalor biomassa sawit sebagai bahan energi. Serbuk kayu dimaserasi dengan pelarut aseton dan ekstrak ditambahkan ke dalam biomassa sawit. Analisis proksimat menunjukkan biomassa sawit setelah penambahan zat ekstraktif memiliki kadar air 18.14 - 21.96%, kadar abu 2.85 - 4.51%, kadar zat terbang 72.07 - 76.41%, kadar karbon terikat 19.60 - 23.97%. Peningkatan nilai kalor setelah penambahan zat ekstraktif kayu pinus, agathis, mahoni, nangka, kaliandra masing-masing sebesar 14.32, 7.59, 11.29, 8.22, dan 5.64%. Berdasarkan karakteristik tersebut biomassa sawit berpotensi menjadi sumber energi terbarukan berkalor tinggi dengan penambahan zat ekstraktif. Hasil penelitian menunjukkan bahwa peningkatan nilai kalor biomassa sawit paling tinggi diperoleh setelah penambahan zat ekstraktif kayu pinus (diatas 4000 kkal kg-1).
Keyword: biomassa sawit, ekstraktif, energi, proksimat

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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