Judul: Design of a Dryer in UPLCT
Abstrak: Rajungan merupakan komoditas hasil laut yang memiliki nilai ekonomi tinggi di Indonesia dengan kapasitas produksi 47.895 kg/hari, sehingga ada potensi limbah cangkang sebanyak 25.187 kg/hari yang tersebar di pesisir Indonesia. Hal ini menunjukkan adanya potensi terkait peningkatan nilai tambah limbah cangkang rajungan. Permasalahan yang terjadi adalah cangkang yang tersebar, jumlahnya beragam, dan menimbulkan bau akibat pengeringannya yang tidak efisien. Dalam meningkatkan nilai tambah limbah cangkang rajungan membutuhkan unit pengelolaan limbah cangkang terpadu (UPLCT) yang dapat mengeringkan cangkang dengan kualitas yang sesuai dengan kebutuhan industri pengolah cangkang. Proyek ini bertujuan mendesain alat pengering yang efisien dan ekonomis, memiliki kapasitas yang memadai, menghasilkan kualitas cangkang yang sesuai, mudah dioperasikan, serta mengurangi pencemaran lingkungan. Jenis pengering yang dipilih menggunakan matahari karena dapat menghemat biaya, kualitas yang dihasilkan sesuai (tersortir dengan kadar air < 16 %), mudah dioperasikan, dan dapat mengurangi pencemaran. Alat pengering ini memiliki kapasitas 270 kg/alat dengan dimensi (4,15 x 2,15 x 1,61) m dan lama waktu pengeringan 6,2 jam. Hasil validasi prototipe menunjukkan bahwa desain alat pengering yang diberikan diterima oleh mitra (APRI), pemangku kepentingan dan dapat menjawab permasalahan yang ada., Blue swimming crab is a marine product commodity that has high economic value in Indonesia with a capacity of 47,895 kg/day, so there is a potential for shell waste of 25,187 kg/day scattered on the coasts of Indonesia. This indicates the potential for increasing the added value of crab shell waste. The existing problem are shells that are scattered, have various capacities, and inefficient drying. In order to increase the added value of crab shell waste, an UPLCT is needed which can dry the shells to the specifications desired by the shell processing industry. This project aims to design a dryer that is efficient and cost-effective, has sufficient capacity, produces appropriate shell quality, has an easy process, and reduces environmental pollution. Solar drying was chosen as the drying method because it can save costs, the quality produced is appropriate (sorted with a moisture content <16%), easy to operate, and can reduce pollution. This dryer has a capacity of 270 kg per unit with dimensions (4.15 x 2.15 x 1.61) m and a drying time of 6.2 hours. The prototype validation results show that the dryer design provided is accepted by partners (APRI), stakeholders and can answer existing problems.
Keyword: crab shells, drying, solar drying

Judul: Desain Aliran Proses dan Tata Letak Unit Pengelolaan Limbah Cangkang Rajungan Terpadu (UPLCT)
Abstrak: Cangkang rajungan merupakan sisa limbah hasil produksi rajungan yang belum termanfaatkan dengan baik sampai saat ini. Namun, cangkang rajungan sebenarnya memiliki potensi nilai tambah yang dapat dimanfaatkan dalam berbagai industri. Kandungan nutrisi yang tinggi menjadikan cangkang berpotensi sebagain pupuk dan juga pakan ternak, kemudian kandungan senyawa bioaktif bisa dijadikan produk kitin dan kitosan. Dalam mencapai nilai tambah yang dinginkan perlu penanganan yang tepat, oleh karena itu di desain unit pengelolaan limbah cangkang rajungan terpadu (UPLCT). Desain aliran proses dan tata letak merupakan aspek penting dalam perencanaan UPLCT, desain aliran proses yang baik dapat mengoptimalkan aliran bahan baku, tenaga kerja dan juga efisiensi waktu. Desain tata letak memperhitungkan aliran proses agar penempatan setiap aktivitas sesuai dengan keterkaitannya masing-masing dan meningkatkan produktivitas kerja. Desain tata letak yang dihasilkan memerlukan area seluas 26m x 21m. Desain aliran proses dalam UPLCT dimulai dari penerimaan bahan baku, pengeringan, pengepresan, pengemasan, dan penyimpanan. Rute penjemputan dari UPLCT ke setiap miniplant menempuh jarak sejauh 4210m. Validasi ke semua pemangku kepentingan, bahwa desain disetujui dan sesuai dengan area yang tersedia., The crab shell is the remaining waste from crab production which has not been utilized properly until now. However, crab shell actually has potential added value that can be utilized in various industries. The high nutritional content makes the shells potentially used as fertilizer and also animal feed, then the content of bioactive compounds can be used as chitin and chitosan products. In achieving the desired added value, proper handling is needed, therefore an integrated crab shell waste management (UPLCT) was designed. Process flow design and layout is an important aspect in UPLCT planning, a good process flow design can optimize the flow of raw materials, labor and also time efficiency. The layout design takes into account the flow of the process so that the placement of each activity is in accordance with their respective relationships and increases work productivity. The resulting layout design requires an area of 26m x 21m. Process flow design in UPLCT starts from receiving raw materials, drying, pressing, packaging, and storage. The pick-up route from UPLCT to each miniplant covers a distance of 4210m. Validation to all stakeholders, that the design is approved and in accordance with the available area.
Keyword: Crab Shell, Layout, Process Flow, UPLCT

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model