Judul: Pengaruh suplementasi Zn dan vitamin E dalam ransum terhadap kualitas telur itik yang disimpan selama 21 hari
Abstrak: Kuning telur mengandung asam lemak omega-3 dan omega-6 yang mudah teroksidasi selama penyimpanan, sehingga harus dilindungi. Penelitian ini bertujuan untuk menguji pengaruh penambahan Zn dan vitamin E di dalam ransum terhadap kualitas fisik telur itik lokal yang telah mengalami penyimpanan pada suhu ruang (29.29°-30.07°C) dan di dalam lemari es (5°C) selama 21 hari. Penelitian menggunakan rancangan acak lengkap, dengan 15 perlakuan dan 3 ulangan. Perlakuan merupakan kombinasi dari perlakuan ransum (R1, R2, R3, R4, R5), suhu penyimpanan (T1 and T2), dan lama penyimpanan (D0 and D21). Perlakuan ransum diantaranya: R1 (ransum kontrol), R2 (R1 + 40 IU Vitamin E), R3 (R1 + 80 IU Vitamin E), R4 (R1 + 100 ppm Zn Organik), dan R5 (R1+ 200 ppm Zn Organik). Penelitian ini menggunakan 90 ekor itik petelur. Peubah yang diamati adalah bobot telur, bobot kerabang, bobot albumen, bobot yolk, haugh unit, skor warna kuning telur, dan ketebalan kerabang. Suplementasi 80 IU vitamin E dapat mempertahakan kualitas fisik telur pada telur yang disimpan selama 21 hari pada suhu ruang (29.29- 30.07°C). Suplementasi 200 ppm Zn organik dapat mempertahankan kualitas fisik telur pada telur yang disimpan selama 21 hari pada suhu 5°C.
Keyword: Duck eggs, Physical quality egg, Storage, Vitamin E, Zn organic, Eggs yolk, Omega-3, Omega-6, Egg weight, Eggshell weight, Albumen weight, Yolk weight, Haugh unit

Judul: Quality of Eggs Stored without Egg Trays in Room Temperature and Refrigerator Temperature
Abstrak: Telur merupakan pangan asal hewan dengan kandungan nutrisi yang lengkap, seperti protein, lemak, vitamin, dan mineral. Lama dan suhu penyimpanan dapat mengakibatkan penurunan kualitas telur. Penelitian ini bertujuan untuk mengevaluasi perubahan nilai Haugh Unit, indeks kuning telur, dan indeks albumin telur yang disimpan tanpa rak selama 21 hari. Penelitian ini menggunakan 40 butir telur ayam. Sebanyak 20 telur disimpan pada suhu ruang dan 20 telur lainnya disimpan pada suhu refrigerator. Seluruh telur disimpan dalam wadah tanpa diatur. Pengujian dilakukan terhadap nilai Haugh Unit (HU), indeks kuning telur (IKT), dan indeks albumin (IA) pada hari ke-0, ke-7, ke-14, dan ke-21 penyimpanan dari setiap suhu perlakuan. Setiap pengujian menggunakan 5 sampel telur. Desain penelitian menggunakan metode rancangan acak lengkap dua faktorial dan uji Tukey. Hasil penelitian menunjukkan terjadinya penurunan nilai HU, IKT, dan IA. Penurunan nilai HU, IKT, dan IA berbeda nyata (p < 0,05) antara suhu kamar dan refrigerator. Suhu dingin (refrigerator) dapat mempertahankan kualitas telur ayam., The egg is one of the food of animal origin containing complete nutrients, e.g., proteins, fats, vitamins, and minerals. Storage period and temperature can decrease egg quality. This study aimed to evaluate the change in Haugh Unit, yolk index, and albumin index of eggs that storaged for 21 days without egg tray. This study used forty chicken eggs. Twenty eggs were stored at room temperature, while the twenty other eggs were stored at refrigerator temperature. All eggs were put in bowl. The examination of eggs were carried out for Haugh Unit (HU), yolk index (YI), and albumin index (AI) at the storage of day 1, 7, 14, and 21 from each storage temperature. Every examination used 5 eggs. The study was designed using randomized block design with two factorials and Tukey test. This study showed that HU, YI, and AI of eggs in both temperature decreased. The decrease of HU, YI, and AI was significantly different (p < 0,05) between both temperatures. The storage of eggs in refrigerator could keep the quality of eggs.
Keyword: Haugh Unit, indeks albumin, indeks kuning telur, suhu refrigerator, suhu ruang

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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