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Ari Bawono P
Department of Physics, Universitas Diponegoro Semarang

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SIFAT ELEKTROOPTIS SEBAGAI PARAMETER INDIKASI MUTU BERBAGAI JENIS MINYAK GORENG KEMASAN Murni, Sri; Firdausi, K Sofjan; Hidayanto, Eko; Bawono P, Ari
BERKALA FISIKA Vol 15, No 4 (2012): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract In this paper, we introduce the change of polarization angleβ induced by external electric field, as a quality indication of several edible oils without preliminary treatment. The averagevalue ofβ in the interval of applied potential difference plays important role as level of number offree radicals produced in the edible oils. The samples used were olive oil, extra olive oil, palm oil,and corn oil. Theβ value was obtained by measurement of the change polarization angle as the function of magnitude the electric field on the samples. The electric field was produced by DCvoltage power supply on two parallel plates in a separated distance of 2.5 cm and in area of 5 cm× 3 cm. The source of light used was He-Ne laser 1 mW (λ=633 nm). The experiment result showsthat for all the fresh frying oil samples the polarization angle has value between 2.3× 10/V and3.3× 10-4 0/V in the experimental condition. The extra olive oil has the smallest value while palmoil has the greatest. According to the previous study, the olive oil is relatively the best oil.Keywords: frying oil, electrooptics, polarization angle
REVIEW PENGUJIAN HUKUM MALUS DAN SIFAT OPTIS AKTIF LARUTAN GULA MENGGUNAKAN SISTEM DETEKSI CAHAYA Amitasari, Ria; Istiyawan, Wardono; Sugito, Heri; Bawono P, Ari; Firdausi, K Sofjan
BERKALA FISIKA Vol 16, No 1 (2013): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract In this paper, we review the test results of Malus’ Law and optical activity of sugarsolution using a system light detector. Two polarizers were used in the experiment to serve thechoice of a certain direction of electric field of light and to determine the change of polarizationangle. The change of transmitted intensity were measured using LDR detector which was thenacquisitioned by microcontroller and displayed via LCD and computer using  Microsoft Visual Studio C#. The experiment result is in agreement to the Malus’ Law with correlation coefficient of 0.99, and by using the equipment we obtain linearity between the change of polarization angle andconcentration of sugar solution, which is appropriate to the theory, as well. The specific rotarypower is (54±2) o/dm(g/mL) in the experimental uncertainty.Keywords: Malus law, change of polarization angle, light detector
KOMPUTERISASI TABEL SIFAT-SIFAT TERMODINAMIK DARI H2O, R-12, DAN R-22 (PROTAMIK) Khuriati RS, Ainie; Detika, Detika; Bawono P, Ari
BERKALA FISIKA Vol 16, No 1 (2013): Berkala Fisika
Publisher : BERKALA FISIKA

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A computer program has been created which is used to display the thermodynamic properties (T, p, v, u, h, and s) of the working fluid of the commonly used on the power generation and processindustries,  H2O, R-12, and R-22. It  also calculates  the thermodynamic properties as function of  saturationtemperature and quality and saturation  pressure and quality. Program was developed using the thermodynamic properties of steam properties from 1967 ASME Steam Table [1] andASHRAE tables [5].Keywords: thermodynamics, properties, steam tables, refrigerant tables, quality.