Judul: Production of Alginate-Silica-Nanocellulose Composites with Cinnamon Essential Oil for Antimicrobial Sachet
Abstrak: Food safety become important requirement that must be fulfilled before being consumed by people. The use of food packaging materials is an important role in maintaining food quality and safety. Antimicrobial sachet is one of the innovative technological concepts of active packaging that can inhibit undesirable microorganisms so that it can extend the shelf life of products. Silica and calcium alginate is used as a carrier material for antimicrobial compounds for the production of sachets. Nanocellulose is used as a filler in carrier matrix composite. One source of nanocellulose is oil palm empty bunches (OPEFB). The purpose of this final project is to produce the antimicrobial sachet using mixture of alginate and silika as the carrier materials with addition of nanocellulose (0, 1, 3, 5%) as a filler, and cinnamon essential oil as antimicrobial agent. The obtained nanocellulose and composites was analyzed by several analysis such as, morphologhy was observed by scanning electron method (SEM), chemical component by fourier transform infrared (FTIR), hardness by texture analyzer, thermal properties by thermogravimetric analysis (TGA), and crystallinity by X-ray diffraction (XRD). The performance of antimicrobial sachet was tested by release of essential oil and antimicrobial test. Addition of nanocellulose to the composite showed good mechanical properties and the morphologhy BDNC5 more compact and spherical than others. The antimicrobial sachet with addition of nanocellulose was proven to slow down the release of CEO from composite beads significantly, and had high inhibitory to microbial activity. The sachet that had good suppress the microbial growth is BDNC5. Almost all microorganisms tested by sachet BDCN5 showed high inhibitory, 5.43% in Escherichia coli, 5.19% in Salmonella sp, 3.36% in Aspergillus sp, and 8.72% in Staphylococcus aureus.
Keyword: antimicrobial sachet, nanocellulose, cinnamon essential oil

Judul: Rekayasa proses sintesa nano seng oksida dari hasil samping industri galvanis sebagai bionanokomposit untuk kemasan antimikroba.
Abstrak: Galvanizing industry is an developer where fulfill metal-based product requirement in the society. Generally, galvanizing industry is involving plating process to avoid corrosion, with zinc is the metal commonly used for the purpose. This industry produces seng dross as byproduct that still contains zinc of 96.57%. Seng dross could be utilized using hydrometallugical method with glacial acetic acid extraction which would produce zinc acetate that could act as precursor. One of the materials commonly used in nanotechnology is nano zinc oxide. Zinc oxide nano particle is having antimicrobial properties. Zinc oxide nano particle could be used as additive that has antimicrobial effect of packaging, to prolong shelf life of product without addition of preservatives. Packaging material used is natural polymer of bionanocomposite. This material could be degraded and safe for the environment. The aims of this research are to obtain zinc acetate extraction process from zinc dross, obtaining method and process condition of zinc oxide nano particle synthesis, to produce nano particle of zinc oxide, to obtain the formulation of bionanocomposite containing zinc oxide, and to obtain the formulation of bionanocomposite antimicrobial packaging. This research was conducted in several stages, namely: (1) Zinc dross extraction into zinc acetate. Three variables were used in this process, namely temperature (130o C, 150o C,and 170o C), acetic acid concentration (20%, 40% and 60%), and processing time (1, 2, and 3 hours). (2) Nano zinc oxide synthesis, using combined method of sol-gel,sonochemistry and calcination. Variables used were pH (8, 10, and 12), sonication time (45, 60, and 75 minutes). (3) Bionanocomposite production process. Variables used were polyvinyl alcohol concentration (0.5%, 1%, and 1.5%) and nano zinc oxide (0.05%, 0.10% and 0.15%). In application test, nano zinc oxide acts as antimicrobial compound on fresh meat packaging, using variables of zinc oxide nanoparticles (0%, 1%, 2%, 3% and 4%), and storage time (2, 4, 6, and 8 days) Results show that optimum condition of seng dross extraction on glacial acetic acid was at 130o C, acetic acid concentration 60% and processing time of 1 hour. This condition gives zinc acetate with zinc content of 75.39% and solubility of 99%. Optimum process condition of nano zinc oxide production was pH 10 and sonication time of 60 minutes. This condition produces zinc oxide nano particle with size of 120 nm, nanorod shapes, regular and homogenous, and containing zinc 87.31%. Optimum condition of bionanocomposite development was at polyvinyl alcohol concentration of 1.0%, and nano zinc oxide concentration of 0.10%. On application of bionanocomposite as antimicrobial packaging the optimum condition was nano zinc oxide concentration of 2% and storage time of 8 days. Antimicrobial bionanocompositepackaging material composition is found on the ration of tapioca : carrageenan : glycerol : polyvinyl alcohol : nano zinc oxide is 5 : 1 : 1 : 1 : 1 : 2. Application of antimicrobial bionanocomposite packaging material for fresh meat show that after 8 days in temperature of 9o C, the aroma and color organoleptic properties was maintain at good quality. Increase in pH was observed, therefore no E. coli bacteria was growing.
Keyword: zinc dross, nano zinc oxide, bionanocomposite, antimicrobial

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular