Judul: Physicochemical, Antioxidant, and Organoleptic Properties of Yogurt with the Addition of Moringa Leaf Powder (Moringa Olifera)
Abstrak: Yogurt susu sapi merupakan salah satu jenis minuman dari hasil proses fermentasi yang memiliki kandungan yang baik. Penambahan ini berguna untuk menambah kandungan gizi pada yogurt. Daun kelor mengandung banyak zat gizi yang dapat mengatasi masalah gizi buruk. Penelitian ini bertujuan menganalisis sifat fisikokimia, antioksidan dan organoleptik yogurt susu sapi dengan penambahan serbuk daun kelor. Taraf pemberian serbuk daun kelor tersebut adalah 0% (P1) sebagai kontrol, 5% (P2), 10% (P3), 15% (P4). Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan tiga kali pengulangan. Pengujian yogurt daun kelor terdiri dari analisis fisikokimia (nilai pH, viskositas, kadar abu, dan kandungan protein), sifat antioksidan (aktivitas dan kapasitas antioksidan) dan Uji organoleptik terhadap warna, aroma, dan rasa, tekstur dari produk yogurt daun kelor. Hasil penelitian ini menunjukkan bahwa penambahan serbuk daun kelor pada yogurt berpengaruh nyata (P<0,05) terhadap pH, viskositas, kadar abu, kadar protein, dan antioksidan. Selain itu hasil hedonik dan mutu hedonik menunjukan berpengaruh nyata (P<0,05) pada parameter warna, aroma, rasa, dan tekstur., Cow's milk yogurt is one type of beverage from the fermentation process that has good content. This addition is useful for increasing the nutritional content of yogurt. Moringa leaves contain many nutrients that can overcome the problem of malnutrition. The purpose of this research is to analyze the physicochemical, antioxidant and organoleptic properties of cow's milk yogurt with the addition of Moringa leaf powder. The level of administration of Moringa leaf powder was 0% (P1) as a kontrol, 5% (P2), 10% (P3), 15% (P4). This study used a completely randomized design (CRD) with three repetitions. Moringa leaf yogurt testing consisted of physicochemical analysis (pH value, viscosity, ash content, and protein content), antioxidant properties (antioxidant activity and capacity) and Organoleptic Test on color, aroma, taste, texture of Moringa leaf yogurt products. The results of this study showed that the addition of Moringa leaf powder to yogurt had a significant effect (P<0.05) on pH, viscosity, ash content, protein content, and antioxidants. In addition, the results of hedonic and hedonic quality showed a significant effect (P<0.05) on the parameters of color, aroma, taste, and texture.
Keyword: antioksidan, daun kelor, yogurt

Judul: Sifat Fisik, Kimia, dan Organoleptik Gelato dengan Penambahan Ekstrak Daun Kelor
Abstrak: Gelato adalah salah satu jenis es krim yang berasal Italia yang marak ditemui dan digemari masyarakat Indonesia namun memiliki zat gizi yang kurang lengkap. Penelitian ini bertujuan menganalisis karakteristik fisik, kimia, dan uji organoleptik gelato dengan penambahan ekstrak daun kelor. Rancangan Acak Kelompok (RAK) digunakan pada uji sifat fisik, kimia, dan organoleptik gelato dengan perlakuan persentase penambahan 0%, 3%, dan 6% dengan 3 kali pengulangan. Data dianalisa dengan ANOVA dan Friedman Test untuk data organoleptik. Hasil penelitian menunjukkan bahwa penambahan ekstrak daun kelor berpengaruh nyata terhadap sifat fisik yakni overrun, daya leleh, dan pH dan sifat kimia gelato. Hasil uji hedonik menunjukkan bahwa penambahan ekstrak daun kelor berpengaruh nyata (P<0,05) terhadap parameter warna sedangkan pada uji mutu hedonik berpengaruh nyata (P<0,05) terhadap parameter warna, rasa, dan aroma. Penggunaan ekstrak daun kelor 6% pada gelato merupakan formulasi terbaik pada penelitian ini berdasarkan pengujian fisik, kimia, dan organoleptik., Gelato is a type of ice cream that originates from Italy and is widely found and loved by the people of Indonesia but it has a less complete nutritional profile. This research aims to analyze the physical, chemical, and organoleptic characteristics of gelato with the addition of moringa leaf extract. A randomized complete block design (RAK) was used for the physical, chemical, and organoleptic properties of gelato with treatments of 0%, 3%, and 6% addition percentages with three times replicated. The data is analyzed using ANOVA and Friedman Test for organoleptic data. The results showed that the addition of moringa leaf extract significantly affected the physical properties such as overrun, meltdown resistance, and pH, and the chemical properties of gelato. Hedonic test results indicated significant effects (P<0.05) of moringa leaf extract addition on color parameters, while significant effects (P<0.05) were observed in hedonic quality tests for color, taste, and aroma parameters. The use of 6% moringa leaf extract in gelato was found to be the best formulation based on physical, chemical, and organoleptic tests in this study.
Keyword: daun kelor, sifat kimia, uji organoleptik, gelato, sifat fisik

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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