Judul: Sintesis Nanosilika dari Abu Ketel Industri Gula Mengguakan Metode Ko-presipitasi dengan Template Pati.
Abstrak: Boiler ash is by product of the sugar industry which is not yet widely used. Boiler ash is highly silica content that can be utilized as nanosilica. The purpose of this study to synthesis nanosilica using boiler ash with the addition of tapioca and corn starch as a template. This research aims to know the effect of tapioca and cornstarch on characteristic of nanosilica, and also give information about the aplication of nanosilica with starch template. The researchs consist of four part that is preparation of material, synthesis of silica, synthesis of nanosilica, and characterization of nanosilica. 49,69% bagasse ash is composed of silica and after the furnace at a temperature of 7000 C the furnace ash containing 78,75% silica. Characteristics of nanosilika was multiphase consist of quartz, tridimit, and krisrobalit phase with cristobalite as the predominant phase.The most high crystallinity of nanosilika was 82,070% at treatment without addition of the template and the smallest crystallinity was 49,063% on addition corn starch at 33,33%. Starch contain of amylose that have contributed on decreasing cristalinity of nanosilica. Particle size of nanosilika was more homegen with the addition of corn starch when PDI’s number was above 0,1. Observation by SEM showed that the particle has polygonal form and looks spreads. Commonly, the effect of starch as a template was decreased the particle size, distrubution of particle, cristalinity, and cristal size. Characteristic of nanosilika that produced by starch’s template can aplicate as a silica-polymer nanocomposit and as a filler for ceramic’s material.
Keyword: boiler ash, co-presipitation, nanosilica, starch

Judul: Penambahan Template Kitosan dan Albumin pada Sintesis Nanosilika Abu Ketel Industri Gula dengan Metode Kopresipitasi.
Abstrak: Nanosilica has many potential application in widely sectors. Boiler ash has contains silica that synthesized using precipitation method. Templating was modification process from precipitation method. The objective of this research was to synthesis nanosilica with template from boiler ash using precipitation method, determine the effect of chitosan and albumin templates on the characterization of nanosilica, determine the potential application based on characterization of nanosilica. This research consist of several stages, preparation of boiler ash, silica extraction, synthesis of nanosilica, testing of material, testing and characterization of nanosilica, and analyze of data. Boiler ash contained 49.69% silica and furnace ash contained 78.75% silica. Increasing concentration of chitosan and albumin templates was decrease amount of diffraction peak, diffraction peak intensity, decrease average of crystal size, narrow of crystal size distribution, and narrow of particle size distribution (PDI) curve. Degree of crystallinity nanosilica with chitosan template has ranges 34.40-54.69% and with albumin template has ranges 39.33-68.79%. Crystal size nanosilica has ranges 35.87-61.57 nm. Particle size nanosilica has ranges 228.39-1369.23 nm. PDI value nanosilica has ranges 0.09-0.297. Nanosilica has potential application as compose top layer of ultrafiltration membrane, compose porous support of ultrafiltration membrane, and support component of catalyst.
Keyword: albumin, boiler ash, chitosan, nanosilica, precipitation

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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