Judul: Evaluasi Variabilitas Bobot Bersih Mie Snack Gorengan pada Proses Packing Vertikal di PT XYZ
Abstrak: Mie Snack merupakan pangan olahan berbahan dasar tepung terigu yang pengolahannya menggunakan proses penggorengan. Seiring dengan tingginya permintaan produk mie snack dari konsumen, diperlukan upaya dari PT. XYZ untuk meningkatkan jumlah produksi dan menekan jumlah broken produk karena variasi bobot produk. Tujuan penelitian ini adalah mengidentifikasi dan menganalisa faktor penyebab variasi bobot bersih mie snack gorengan di PT. XYZ serta menghitung nilai Cp (Capability process) dan nilai Cpk (Index capability process) dari proses pengemasan pada mesin packing vertikal. Penelitian ini menggunakan metode PDCA (Plan, Do, Check, Action) dengan alat bantu diagram Ishikawa dan control chart dari seven tools. Hasil penelitian menunjukkan bahwa penyebab variasi bobot produk berasal dari faktor mesin, yang merupakan pengaruh dari pelat takaran yang belum distandardisasi; faktor metode dan manusia, dimana proses pengemasan sangat bergantung pada pekerja dan operator; serta faktor material. Tindakan perbaikan untuk meningkatkan nilai kapabilitas proses pengemasan pada mesin packing vertikal adalah memperkecil ukuran takaran dengan melapisi pelat takaran. Tindakan perbaikan yang dilakukan telah menaikan nilai Cp mie snack ‘Yakisoba’, ‘Migor’, dan ‘Mi Seblak’ sebesar 0,211;0,317;1,586. Namun, hasil observasi pada produk mie snack menunjukkan kurangnya keseragaman komposisi bahan pada produk akhir mie snack. Walaupun nilai Cp proses pengemasan meningkat akan tetapi nilai Cpk indeks kapabilitas proses pengemasan nilainya dibawah satu. Hal ini menunjukkan spesifikasi mesin packing vertikal yang digunakan PT XYZ tidak mampu memproduksi produk mie snack dengan spesifikasi yang ditetapkan perusahaan., Noodles snack is a processed food made from wheat flour using a frying process. Along with the high demand for snack noodle products from consumers, efforts are needed from PT. XYZ to increase the amount of production and reduce the number of broken products due to variations in product weight. The purpose of this study was to identify and analyze the factors causing variations in net weight of fried snack noodles at PT. XYZ and also calculate the value of Cp (Capability process) and Cpk (Index capability process) of the packaging process on vertical packing machine. This study uses the PDCA (Plan, Do, Check, Action) method with Ishikawa diagrams and control charts from SEVEN TOOLS. The results showed that the cause of the variation in product weight came from the engine factor, this was the influence of the measuring plate which had not been standardized; method and human factors, where the packaging process is highly dependent on workers and operators; and material factors. The corrective action to increase the value of the packaging process capability on vertical packing machines is to reduce the size of plate by coating the plate. The corrective action taken has increased the Cp value of ‘Yakisoba’ snack noodles, ‘Migor’ snack noodles, and ‘Mi Seblak’ snack noodles by 0.211; 0.317; 1.586. However, the results of observations on snack noodle products show a lack of uniformity in the composition of the ingredients in the final snack noodle product. Although the Cp value of the packaging process increases, the Cpk value of the packaging process capability index is below one. This shows that the specifications of the vertical packing machine used by PT XYZ are not able to produce snack noodle products
Keyword: PDCA cycles, Capability process, Index capability process, Vertical packing machines

Judul: Evaluasi Penerapan GMP dan Peluang Cross Contamination Area Packing pada Produksi Mi Instan di PT XYZ.
Abstrak: PT XYZ is a ready-to-eat food industry that produces instant noodles. Quality assurance and food safety are essential aspects for businesses to compete effectively. PT XYZ implements the Good Manufacturing Practice (GMP) system to ensure product safety. The implementation of the GMP system is evaluated based on checklists from the Directorate General of Agro Industry Regulation No. 30/IA/Per/12/2011 on Technical Guidelines for the Assessment of the Application of Good Processed Food Production and the Indonesian National Agency of Drug and Food Control (BPOM) Regulation No. 22 of 2021 on Good Processed Food Processing Methods (CPPOB). Based on the checklist of Directorate General of Agro Industry Regulation No. 30/IA/Per/12/2011, PT XYZ is rated at Level I. Level I indicates that the number of deviations found in the minor category is between 0- 6, major deviations are 0-5, and critical deviations are 0. One minor finding from the Directorate General of Agro Industry checklist is the slippery condition of the floor surface. This finding does not affect the quality of the final product but should be considered for the safety of employees and is thus categorized as minor. On the other hand, based on the BPOM Regulation No. 22 of 2021 checklist, PT XYZ is rated at Level A (excellent). Level A indicates that the number of deviations found in the minor category is between 0-6, major deviations are 0-5, critical deviations are 0, and there are no serious deviations. The sanitation and hygiene in the area where complementary seasonings are packed, both on the packaging and among workers, have been done well and effectively, as evidenced by the Total Plate Count test results which are below the company's internal standards. However, sanitation regarding the air in the packing area needs to be improved to maintain product quality and safety. The use of automatic air sanitation equipment can be implemented or used in the complementary seasoning packing area.
Keyword: GMP, food safety, instant noodles, sanitation

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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