Judul: Study of Dairy Cattle Diseases Incidence Rate in Koperasi Serba Usaha (KSU) Tandangsari Sumedang 2014-2019
Abstrak: Studi ini bertujuan untuk mengetahui kejadian kasus penyakit pada sapi perah yang sering terjadi dan dugaan hubungannya dengan cuaca serta faktor lain di KSU Tandangsari, Sumedang. Data studi diambil dari laporan mahasiswa PKL PPDH FKH IPB periode 2014-2019. Data direkap dalam bentuk periode tiga bulanan berturut-turut (trimester). Penyakit yang dibahas pada studi ini yaitu 10 kejadian penyakit yang paling sering dilaporkan. Sebanyak 10 penyakit tersebut yaitu mastitis klinis, hipokalsemia, timpani rumen, enteritis, endometritis, laminitis, indigesti rumen, abses, carpal/tarsal arthritis, dan left displaced abomasum (LDA). Total penyakit yang dilaporkan berjumlah 34 penyakit dengan jumlah kasus yang terjadi dari total penyakit tersebut sebanyak 358 kasus. Faktor cuaca diduga berpengaruh terhadap tingkat kejadian penyakit mastitis klinis, hipokalsemia, endometritis, laminitis, dan LDA. Penyakit lain seperti timpani rumen, abses, indigesti rumen, carpal/tarsal arthritis, dan enteritis belum dapat diduga dipengaruhi oleh kondisi cuaca karena kejadian kasus yang hampir sama jumlahnya pada kedua musim. Kejadian penyakit yang sering terjadi juga dapat dipengaruhi oleh faktor lain seperti kebersihan dan sanitasi kandang, perubahan dan komposisi pakan, perkembangan mikroorganisme kandang, dan penggunaan material pada kandang yang kurang tepat., The objectives of this study were to analyze the incidence rate of dairy cattle internal diseases case and the alleged relationship with weather and external factors at KSU Tandangsari, Sumedang. The study data was taken from the reports of PKL PPDH FKH IPB students for the period 2014-2019. The data was recapitulated in the form of three consecutive months (trimester). The diseases discussed in this study were the 10 most frequently reported disease cases which were clinical mastitis, hypocalcemia, tympanic rumen, enteritis, endometritis, laminitis, rumen indigestion, abscess, arthritis carpal/tarsal, and left displaced abomasum (LDA). The total number of diseases reported were 34 variants of cases from 358 individual cases. Weather factors were assumed to affect the incidence of clinical mastitis, hypocalcemia, endometritis, laminitis, and LDA. Other diseases such as rumen tympanic, abscess, rumen indigestion, carpal/tarsal arthritis, and enteritis cannot be predicted to be influenced by weather conditions because the cases incidence is almost similar in both seasons. The disease incidence can also be influenced by other factors such as cleanliness and sanitation of the cage, changes and composition of feed, the development of microorganisms in the cage, and the use of material in the cage which was not appropriate.
Keyword: Dairy cattle, Incidence of disease, KSU Tandangsari, Weather factors

Judul: Analysis of the Dairy Cattle Internal Diseases Cases Occurrence at KPSBU Lembang During 2015-2019
Abstrak: Studi ini bertujuan mengetahui tingkat kejadian kasus penyakit dalam pada sapi perah di KPSBU Lembang tahun 2015-2019 dan dugaan hubungannya dengan faktor cuaca. Data kejadian penyakit diperoleh dari Laporan Praktik Lapang Pelayanan Kesehatan Klinik Sapi Perah oleh mahasiswa PPDH IPB di KPSBU Lembang tahun 2015-2019. Data kejadian penyakit yang didapatkan kemudian dibandingkan dengan dinamika cuaca di daerah Lembang. Kejadian penyakit dikelompokkan berdasarkan trimester kejadian waktu yaitu trimester pertama (Januari – Maret), trimester kedua (April – Juni), trimester ketiga (Juli – September), hingga trimester keempat (Oktober – Desember). Didapatkan sepuluh besar penyakit yang paling banyak terjadi. Penyakit yang diduga berhubungan dengan cuaca terutama musim hujan adalah artritis, enteritis, dan timpani. Penyakit yang diduga tidak berhubungan dengan cuaca adalah mastitis, parturient paresis/milk fever, pododermatitis, dan abses. Penyakit yang diduga berhubungan dengan cuaca kering/musim kemarau adalah retensi plasenta., The objectives of this study were to analyses the internal disease cases incidences rate in KPSBU Lembang since 2015 until 2019 and its suspected correlation to the weather. Data were collected from Laporan Praktik Lapang Pelayanan Kesehatan Klinik Sapi Perah written by PPDH FKH IPB students at KPSBU Lembang since 2015 until 2019. The collected data were compared to the weather dynamics at Lembang region. The diseases occurrence was classified based on monthly trimester, the first trimester (January – March), second trimester (April – June), third trimester (July – September), and fourth trimester (October – December). Based on the data, there were ten most frequent diseases that occurred at KPSBU Lembang. Diseases which were suspected to correlate with the rainy weather were arthritis, enteritis, and tympany. The disease which was suspected to correlate with the dry weather was placenta retention. Diseases that were not suspected to correlate with the weather were mastitis, parturient paresis/milk fever, pododermatitis, and abscess.
Keyword: dairy cattle, internal diseases, KPSBU Lembang, trimester, weather

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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