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Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) is the most stable form of calcium phosphate and widely used in various medical applications, mainly in orthopedics and dentistry due to its close similarities with the inorganic mineral component of bone and teeth. This study aims to synthesize hydroxyapatite from duck eggshell using the precipitation method. The duck eggshell was calcined, hydrated (slaking) and underwent carbonation to form Precipitated Calcium Carbonate (PCC).  Afterwards, (NH4)2HPO4 was added to produce HAp by varying the molar ratio of Ca/P by 1.67, 1.77 and 1.87 and stirring speed by 200, 250, 300rpm under basic condition (pH 10 – 11). The best results were obtained at a molar ratio of 1.77 with 200rpm stirring speed. Furthermore, the X-ray Diffraction (XRD) analysis showed that its crystals were hexagonal with sizes of 23.062nm, in the absence of other crystalline phases. Therefore, the hydroxyapatite was obtained in the agglomerates form with a specific surface area of ??55.929m2/g.

Doughnuts are one of the most popular sweet foods for people of all ages around the world. Although made from simple ingredients such as flour, sugar, eggs, yeast, milk powder, salt, water, and margarine, however producing doughnuts requires special techniques to produce good-quality doughnuts. It needs more energy, even physically and electrical equipment. A workshop on doughnut production with autolyze method for Dharma Women Association, Faculty of Engineering, University of Riau, was conducted to increase the knowledge and skills of members of the organization in making healthy dishes for the family. In this workshop, doughnuts were made using the autolysis method, which is mixing bread flour with water and then keeping the dough until gluten was formed. The formation of gluten is one indicator of the formation of smooth, soft, and elastic dough. The workshop results showed high interest among the Dharma Women Association members in making doughnuts with this alternative method.

Liquid waste from processing cassava into tapioca starch is carbohydrate-rich waste and can be used as a growth medium for the Acetobacter xylinum, which is useful in producing one of the fermentation products, i.e. nata. Several factors influence the production of nata, one of them is the addition of nutrients in the form of nitrogen in the fermentation medium. The nitrogen source used is usually from inorganic fertilizers, such as urea and ammonium sulfate. In this study, fermentation of tapioca starch wastewater was developed, using a natural sources of nitrogen derived from soybean and green bean sprouts extract. Nata was made by treating various concentrations of soybean and green bean sprouts extract (3%, 4%, 5%) and fermentation time (6 days, 7 days, 8 days, 9 days and 10 days). The characteristics of the nata product were seen from the thickness and yield of the nata. The nata de cassava product's optimum results were tested for thickness, yield, and moisture content. The results showed that the best type of natural nitrogen source was soybean sprouts extract 5%, fermentation time of 10 days with a thickness of 0.55 cm, the water content of 97.58%, and yield of 63.09%

Plastic is a type of packaging that is often used in everyday life, however, in general, the plastic used is synthetic plastic which takes a very long time to decompose. Bioplastic is an environmentally friendly plastic film made from organic materials so that it can decompose naturally with the help of microorganisms. This study aims to determine the effects which have the potential as a supporting material in increasing bioplastic characteristics such as thickness, water absorption and biodegradation. The research method was to use experiment and analysis of varian. Durian seed flour is carried out through a process of sorting, washing, stripping, soaking, slicing, drying, packing and storing. Meanwhile, the method of making bioplastics is done by mixing tapioca flour, cornstarch, durian seed flour of adding various durian seed flour: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 grams, distilled water, acetic acid and glycerin. The analysis results obtained on the test of bioplastic characteristics, namely, thickness test ranging from 0.63 mm - 0.84 mm and  water resistance test ranging from 71,43%-86,54% which water absorption test ranging from 13.46% - 28.57% and the biodegradability test ranging from 17.78% - 47 , 06%.  Keywords: durian seeds, bioplastics, biodegradability, flour ABSTRAK Plastik adalah jenis pengemas yang sering dimanfaatkan dalam kehidupan sehari-hari, akan tetapi pada umumnya plastik yang digunakan merupakan plastik sintetik yang membutuhkan waktu yang sangat lama untuk  terurai. Bioplastik merupakan film plastik yang ramah lingkungan yang terbuat dari bahan-bahan organik sehingga dapat terurai secara alami dengan bantuan mikroorganisme. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan tepung biji durian yang berpotensi sebagai bahan penunjang dalam meningkatkan karakteristik bioplastik seperti ketebalan, ketahanan terhadap air dan biodegradasi. Metode penelitian adalah menggunakan eksperimen dan sidik ragam data. Tepung biji durian dilakukan melalui proses penyortiran, pencucian, pengupasan, perendaman, pengirisan, pengeringan, penepungan dan penyimpanan. Sedangkan untuk metode pembuatan bioplastik dilakukan dengan mencampurkan tepung tapioka, tepung maizena, tepung biji durian dengan variasi: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 gram, akuades, asam asetat dan gliserin. Hasil analisa yang didapat pada pengujian karakteristik bioplastik yaitu, uji ketebalan yang berkisar 0,63 mm – 0,84 mm, uji ketahanan terhadap air yang berkisar 71,43%-86,54% dengan penyerapan air berkisar 13,46 % - 28,57% dan uji biodegradibilitas yang berkisar 17,78% - 47,06%. Kata kunci: biji durian, bioplastik, biodegradibilitas, tepung.

Brick is a building material that is often used for residential walls. The bricks in this study were bricks with the addition of palm frond charcoal in the manufacturing process. The aims of this study were (1) to determine the effect of adding palm stem charcoal on the manufacture of red bricks in terms of compressive strength, water absorption (Suction rate) and apparent density (apparent density). (2) Comparing the test results with the SNI 15-2094-2000 standard. The manufacture of experimental bricks begins with adding clay with pulverized palm frond charcoal in a ratio of 100:0, 95:5, 90:10, 85:15 and 80:20, then molded, dried, burned and tested for new mechanical properties. brick. In this study, the compressive strength of bricks that enter class 100 is a ratio of 100:0 and 95:5 namely 11.75 Mpa and 10.10 Mpa, then bricks grade 50 is a ratio of 90:10 and 85:15 which is 8.08 Mpa and 6.27 Mpa. The water absorption capacity of bricks that meet the requirements of SNI 15-2094-2000 is a ratio of 100:0 and 95:5, namely 18.65% and 19.74%. The apparent density of bricks that meet the requirements of SNI 15-2094-2000 are the ratios of 100:0, 95:5, 90:10 and 85:15, which are 1.63 g/cm3, 1.54 g/cm3, 1,37 g/cm3 and 1.24 g/cm3. Bricks that meet the standards and are recommended as masonry bricks are bricks with a ratio of 95:5.

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