Judul: Fraksi Aktif Antioksidan dari Ekstrak Kulit Kayu Sungkai (Peronema canescens Jack.)
Abstrak: Sungkai (Peronema canescens Jack.) bark extract is potentially containing extractive materials with antioxidant properties. The objective of this research was to fractionate 70% of ethanol extract of sungkai bark, hydrolize the n-hexane residue, determine fraction content and antioxidant activity using in vitro testing, and analyze chemical compounds found in three of the most active fraction. Fractionation was conducted using solvent-solvent extraction with n-hexane and ethyl acetate. Antioxidant activity was examined using 1,1-difenil-2-pikrilhidrazil (DPPH) method. The chemical components of three most active fraction were analyzed by gas chromatography mass spectrometry (GC-MS). Extract value of n-hexane fraction was the highest levels.. The three most active fractions with antioxidant properties are non-hydrolized etil acetate, n-hexane, and hydrolized ethyl acetate (IC50 43.67, 44.55, and 53.34 μg/mL). Phenolic compound identification shows several dominant compounds: quinic acid, guaiacol, hydroquinone, isovanillic acid, genkwanin, catechol, and benzoic acid. Those compounds are categorized as phenol and own strong antioxidant activity
Keyword: phenol, sungkai, antioxidant

Judul: Total Fenolik dan Flavonoid serta Aktivitas Antioksidan Ekstrak Kulit Kayu Sengon (Paraserianthes falctaria (L.))
Abstrak: (Paraserianthes falcataria (L)) is widely used in wood industry and resulted many wastes. The leaf was found to have antioxidant activity, but the bark is still reused. The researches about (Paraserianthes falcataria (L)) bark that have been conducted was not studied to show potency of natural antioxidant. This research was performed to determine the antioxidant activity of (Paraserianthes falcataria (L)) bark extract. Phytochemical scavenging showed that aqueous, ethanol 70%, and 96% bark extracts were positively reacted to saponin, flavonoid, tanin, steroid, and triterpenoid test, while the only negative result was happened to alkaloid test. The highest ammount of total phenolic and flavonoid was found in ethanol 70% extract, those were 161.57 ± 3.93 GAE (mg/g) and 64.46 ± 2.94 CE (mg/g) respectively. The highest IC50 value was found in ethanol 96% extract with value of 40.17 ± 0.65 mg/L.
Keyword: antioxidant, flavonoid, phenolic, Paraserianthes falcataria (L) bark

Judul: Implementasi Space Time Composite (STC) Data Model Menggunakan Model Data Relasional
Abstrak: The data model is a concept that describes the data stored in the database and the relationship between the data to the user in logic. Development of data models is very important in the design of the database as the basis of the stage of database design to be made. This study aims to apply the concept of Space Time Composite (STC) on the Model Data storage vector data types that can store enough information and describes the process of drafting objects and objects spatiotemporal evolution over time. From the results of the test queries on the data model that have been created, queries in a system are acquired that can help display the information preparation of objects from time to time and know the history of the object polygon and arc that has undergone changes in topology.
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