Judul: Waxes, policosanols and aldehydes in sugarcane (Saccharum officinarum L.) and okinawan brown sugar (kokuto)
Abstrak: Waxes, long chain alcohols and aldehydes were found in several variants of sugarcane (Saccharum officinarum L.) and Kokuto, a non-centrifuged Okinawan cane brown sugar. Long chain alcohols, policosanols, have been reported to have beneficial effect to human health. The composition of wax in sugarcane was analyzed using HPLC with an evaporative light scattering detector. Sugarcane wax composed of 55–60% aldehydes, sterol esters and wax esters, 32–40% alcohols, and small amounts of triacylglycerols, acids and sterols. Extraction of policosanols performed effectively with hexane and methanol (20:1 v/v), while that of long chain aldehydes was with chloroform and methanol (2:1 v/v). Their composition was determined using GC with a flame ionization detector, whereas their compounds were identified using GC-MS. Sugarcane rinds contained up to 500 mg policosanols and 600 mg aldehydes per 100 g sample of Ni 22 cultivar. The content of policosanol and long chain aldehyde in Kokuto was influenced by its production systems. Compositional analysis of the end product confirmed the presence of policosanols and aldehydes up to 85 mg and 8 mg respectively per 100 g sample of Kokuto A, a product of brown sugar manufacture with open pan heating system. Octacosanol and octacosanal were found to be the major wax components in both sugarcane and Kokuto samples. This study revealed significant difference in content and composition of waxes, policosanols and long chain aldehydes between sugarcane parts, cultivars and harvesting times; also between Kokuto types and production methods.
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Judul: Sintesis Surfaktan Alkil Poliglikosida dari Fatty Alcohol (C16) Sawit dan Glukosa Cair 85% dengan Perlakuan Perbedaan Nisbah Mol.
Abstrak: Surfactants (surface active agents) are the surface tension active compounds that can be produced synthetically chemically or biochemically. Surfactants are used in industry as a bleaching, wetting, foaming materials, as well as emulsifier and others. The addition of the surfactant is expected to optimize the performance of the active ingredient used. This provides opportunities to develop further research. One type of surfactant that is being developed is poliglicoside alkyl surfactants (APG). APG Surfactant is a nonionic surfactant type commonly used in the formulation of some products such as herbicide formulations, personal care products, cosmetics, textile fabric bleaching and surfactants solution for Enhanced Oil Recovery. Raw material of APG surfactant are fatty alcohol from coconut oil oleochemicals or palm kernel oil (fatty alcohol C16) and glucoside 85%. Fatty alcohol is hydrophobic (lipophilic), while glucose is hydrophilic. In this research APG surfactant was synthesized from fatty alcohol palm oil (C16) and 85% liquid glucose. The Purpose of this research is to obtain the best reactant mole ratio of surfactant alkyl Poliglicoside the best of Fatty alcohol (C16) oil with Liquid glucose 85%. This study used a completely randomized experimental design with one factor and two repetition. The treatment used was reactant mole ratio with five concentration level ie 1.5, 2, 2.5, 3 and 3.5. The process used in this research was 2-stage of processes, there are butanolisis and transacetalitations. The best formula was obtain from the ratio of 1 mol glucoside with 1.5 mol fatty alcohool. This product resulted on the lowest interfacial tension of 5.56 x 10-2 dyne/cm. This APG was processed at a temperature of 120-130OC for 2 hours.The pH value was in the range of 8.2-8.52
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Judul: Teknik penentuan posisi bintang berdasarkan pelat foto overlapping
Abstrak: Bintang adalah salah satu objek langit yang menarik untuk diamati. Untuk itu, pengetahuan tentang posisi bintang sangat diperlukan. Posisi bintang di langit dapat dihitung melalui foto bintang. Fotografi astronomi atau astrometri merupakan ilmu yang mempelajari metode untuk menentukan posisi bendabenda langit seperti bintang berdasarkan pelat foto (Kamp, 1967). Sebuah pelat foto berisi citra bintang-bintang yang sudah diketahui posisinya berdasarkan katalog dan citra bintang-bintang yang belum diketahui posisinya. Posisi bintang yang ada di katalog dinyatakan dengan (a,3). Bintang yang belum diketahui posisinya lebih banyak jumlahnya daripada bintang yang sudah diketahui posisinya. Citra bintang pada pelat foto berupa sebuah titik dalam bentuk tetap. Posisinya pada pelat merupakan hasil pengukuran pada bidang kartesius dan dinyatakan dengan (1;,fl). Hasil pengukuran tersebut kemudian direduksi menjadi koordinat terukur (x,y). Hubungan antara (a,3) dan (x,y) didekati dengan sebuah deret dengan konstanta-konsranta deret merupakan konstanta pelat. Nilai konstanta pelat diperoleh dengan menggabungkan hasil pengukuran posisi bintang pada masing-masing pelat menjadi sebuah persamaan normal (Jefferys, 1963). Hasil akhir dari gugus persamaan normal tersebut dijabarkan dalam bentuk nOlasi matriks partisi dan berupa sebuah sistem persamaan linier Ax = b di mana A adalah matriks jarang, dan x merupakan konstanta pelar yang akan dicari nilainya. Untuk menyelesaikan sistem persamaan linier terse but digunakan metode transformasi given. Konstanta pelat yang sudah diperoleh dengan menyelesaikan sistem persamaan linier di atas, kemudian disubtitusi ke sebuah persamaan untuk memperoleh posisi bintang yang tidak tercantum dalam katalog. .
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