Judul: Kajian sifat listrik dan fisik berbagai jenis buah jeruk pada tingkat ketentuannya
Abstrak: Penelitian mengenai mutu jeruk ditinjau dari sifat listrik dan fisiknya belum dilakukan, sejauh ini penentuan kualitas buah jeruk ditentukan dari segi tampilan fisik. Penelitian dilaksanakan di labratorium biofisika dan instrumentasi fisika IPB dengan menggunakan sampel tiga jenis jeruk pasca panen, masing-masing jenis dibedakan kedalam 8 tipe yang dibedakan berdasarkan tingkat ketuanya. Tiap-tiap sampel jeruk utuh dari sari dilakukan karakterisasi fisik (kerapatan, TPT dan pH) dan listriknya (kapasitansi, konduktansi dan loss coefficient).
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Judul: Kajian kapasitansi listrik buah jeruk garut dan sifat fisiko kimianya
Abstrak: Garut citrus is the halimark and trademark of Garut regency and as a constituent component of local symbol Garut regency. Altough the benefits of changes a lot, but it can not be useful with good if not pay attention to the quality of citrus fruit itself. Assuring the quality of fruit can be obtained through postharvest handling. As it is we need a study of the characteristics thet lead to quality evaluation, that include the use of electrical Capacitance and physicochemical evaluation. Study of citrus properties base on electrical capacitance measurement have been doned using alternating current signal of law frequency. The electrical capacitance of citrus was investigated on frequency from 50 Hz to 1 MHz. The cell system was used acrilic and electrode plate conductor from Cuprum. The sample of citrus was put at inside of plate, as dielectric material. Hi LCR Tester Hioki 3532-50 was used to measure electrical capacitance of sample. This equipments was provided with the current source which its frequency earn variation. In addition, the study was conducted physico chemical measurements of citrus fruit. Parameters measured in this study is hardness, total dissolved solids, and acidity. Hardness measurement carried out to indicate the level of fruit maturity. Fruit maturity level is characterized by levels of total dissolved solids and acidity increased. This is different from the hardness. The more mature fruit, the smaller hardness. On the electrical properties, experiment result showed that spectrum of electrical capacitance of citrus was exponentially decreasing. Correlation between electrical capacitance at 1 MHz and total dissolved is positive. Correlation between electrical capacitance and acidicy shaw quadratic.
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Judul: Mathematical model of Hematopoietic Stem Cell in Chronic Myelogenous Leukemia with and without Therapy
Abstrak: Leukemia or blood cancer is a diverse group of neoplastic disease, characterized by the multiplication of abnormal leukocytes or malignant transformation of blood-forming cells in bone marrow and lymphoid tissues. One of the most common types of leukemia is Chronic Myelogenous Leukemia (CML), which is usually diagnosed by the presence of certain chromosomal abnormalities, the so-called Philadelphia chromosome (Ph). One of the treatments of CML is Granulocyte Colony-Stimulating Factor (G-CSF). In this paper, we discuss two Hematopoietic Stem Cell (HSC) models, i.e. HSC without treatment and HSC with G-CSF treatment. The model of HSC without treatment included three equations representing the dynamics of HSC, leukocyte and platelet. Whereas, the model of HSC with G-CSF treatment includes the previous three equations and adds two more equations representing G-CSF injection and G-CSF circulation. The stability behavior of the system approaching the equilibrium points in the simulation study is carried out using Mathematica 7.0. The simulation results show that the G-CSF treatment can successfully decrease the number of HSC, which means reducing the CML.
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