Judul: Studi Patogenesis Infark Jantung Pada Beruang Coklat (Ursus Arctos).
Abstrak: Penelitian ini bertujuan untuk mengetahui patogenesis infark miokardium pada beruang coklat (Ursus arctos) betina berusia 39 tahun dengan pengamatan secara makroskopis dan mikroskopis. Pengamatan mikroskopis dilakukan dengan menggunakan pewarnaan hematoksilin-eosin (HE) dan Masson’s Trichrome (MT). Hasil pemeriksaan makroskopis menunjukkan bahwa secara umum mukosa terlihat pucat. Pengamatan makroskopis lainnya menunjukkan adanya pneumonia interstitial dan edema pulmonum, peradangan kataralis dan hemoragi pada saluran pencernaan, adanya kista dan perdarahan pada ovarium kanan, deplesi pulpa putih pada limpa, kongesti dan nekrosis multifokal pada hati, nefritis interstitial dan infark pada ginjal, serta infark multifokal pada jantung. Pengamatan histopatologi menunjukkan adanya kongesti dan degenerasi hidropis disertai nekrosis multifokal pada hepatosit, deplesi pulpa putih dan splenitis pada limpa, nefritis interstitial kronis disertai infark dan pembentukan kolagen pada ginjal, serta infark multifokal, degenerasi dan vaskulitis pada miokardium. Gambaran histopatologi menggunakan pewarnaan Masson’s Trichrome menunjukkan bahwa beberapa daerah miokardium telah digantikan oleh jaringan fibrosis dan kolagen. Nefritis interstisialis pada ginjal diduga menjadi faktor predisposisi pembentukan iskemik dan infark miokardium.
Keyword: Beruang coklat, infark, makroskopis, mikroskopis, miokardium

Judul: Electrocardiogram of Pigs (Sus scrofa domestica) as Animal Model Candidate of Artificial Myocardial Infarction
Abstrak: Penelitian ini bertujuan mengetahui perubahan aktivitas listrik jantung akibat infark miokardium pada hewan model babi (Sus scrofa domestica) menggunakan elektrokardiografi (EKG). Pengambilan data dilakukan pada tiga ekor babi jantan dengan umur 4-5 bulan. Perekaman data EKG dilakukan sebelum dan setelah prosedur operasi pembuatan infark miokardium pada babi. Parameter yang diamati adalah durasi P, amplitudo P, interval PR, interval QRS, amplitudo R, amplitudo T, interval QT, segmen ST, dan frekuensi denyut jantung yang direkam pada sadapan II. Data yang diperoleh dianalisis menggunakan uji paired sample T test dan dinyatakan dalam nilai rata-rata serta standar deviasi. Hasil rekaman EKG menunjukkan adanya perbedaan nyata pada parameter interval PR, gelombang T, interval QT, segmen ST, dan frekuensi denyut jantung. Hal ini menunjukkan bahwa kondisi infark miokardium mempengaruhi konduksi listrik atau aktivitas kelistrikan jantung.
Keyword: animal model, electrocardiogram, myocardial infarction, Sus scrofa domestica

Judul: Draft force and energy reduction of soil tillage by Selfexcited Vibration method
Abstrak: Soil compaction potentially inhibits plant growth and reduces crop productivity. To loosen the compact soil, however high draft force and energy consumption are needed. The cause of which is due to soil cohesion, adhesion and friction between soil and tillage tool. It’s well known that vibratory-tillage could reduce that soil cohesion, adhesion and friction between soil and tillage tools so that the draft force and energy consumption required is reduced. In this research, soil tillage by self-excited vibration (SEV) method has been conducted. The objective of this research was to obtain vibratory-system of self-excited vibration vibratory-tillage (SEVVT) so that the vibration of the tillage tool will reduce draft force and energy consumption during tillage operation. The research was divided into three steps, i.e.: analytical study, equipment design and experiment study. In the analytical study, the vibration of SEVVT was simulated as a vibration with single degree of freedom system (SDOF) and two degrees of freedom system (TDOF). The vibration of tillage tool was exerted by natural excitation of the varying cutting force. The elasticity of the elastic spring or the inertia of the tillage tool was optimized such that the tillage tool vibrates violently around its resonant frequency. Draft force reductions about 22-47 % were observed. In the second step, the equipment was designed methodologically using VDI2221, with focus on the conceptual design. The embodiment design was then conducted to exemplify that the conceptual design was simple, easy to understand, and economically realizable. In the last step, soil tillage was conducted in a soil bin with the dimension of 1.2 m long, 0.3 m wide and 0.4 m depth. Clay loam soil was conditioned in soil bin into two layer namely hardpan and top soil. The tillage tool was connected to a fixed structure using a new model of semi-elliptical spring. The tillage speeds used were 0.158, 0.212 and 0.265 m/s. Five treatments were tested, i.e.: Non vibratory-system (NST), SDOF with rear spring orientation (RST), SDOF with front spring orientation (FST), TDOF system (TST) and low energy vibratory-system (VST). In the RST orientation, the draft force raised the elevation of the tillage tool tip, and the draft force caused the tillage tool tip elevation decrease in the FST orientation. Compared to NST, the average draft force in the FST orientation showed an increase of up to 46-96 %, whereas a draft force reduction were found in the RST and in the TST treatment. In the VST treatment, a small unbalance mass of 0.24 and 0.35 kg was rotated 530 and 1150 rpm respectively and causing tillage tool vibrate with low amplitude. Compared to NST, draft force reduction about 7.3-38.3 % and energy reduction about 4.8- 14.4% were found.
Keyword: Low energy vibratory-system, Tillage tool, Agricultural machine