Much Azam
Laboratorium Optoelektronika dan Laser, Jurusan Fisika, FMIPA Undip

Published : 4 Documents
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Pengaruh Kenaikan Suhu Cairan Developer Terhadap Densitas Radiograf

BERKALA FISIKA Vol 11, No 3 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

This aim of the research is to obtain an optimal developer temperature. The increase of dilution temperature of developer to radiograph density has been measured. The Research is conducted with measuring radiograph density with a certain exposure factor and materials and varies temperature among 170 C – 320 C.  The result indicates that the higher of temperature is the greater of its density value. The optimal temperature obtained at spanning temperature among 200 C – 230 C.   Key words: The dilution temperature of developer, density of radiograph, optimal temperature

Pengaruh Teknik Tegangan Tinggi Terhadap Entrasce Skin Exposure( ESE ) dan Laju Paparan Radiasi Hambur Pada Pemeriksaan Abdomen

BERKALA FISIKA Vol 11, No 3 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

The measurement for influence of high voltage technique to Entrance Skin Exposure and is Rate of Scattered Radiation Exposure on abdomen inspection has been conducted. The ESE measurement is conducted using Electrometer and is calculated by semi empirical method, while in measurement of rate of scattered radiation exposure using survey meter at a distance of 100 cm from the object by varying data intake points and its direction of detector. The result indicates that the usage of high voltage technique yields absorbent dose of 124 mrad and radiation exposure of 339 mR. It is lower than the standard value of absorbent dose of 322.7 mrad and radiation  exposure of 130,5 mR. The result of measurement is higher than calculation. In measurement of exposure of scattered radiation rate with detector position faced to object, on right side of cathode, it yields 1.03mR/hour with standard voltage and 0.32 mR/hour with high voltage technique. While in measuring  exposure of scattered radiation rate and back-scattered obtained result on A’ and C’ (close to anoda and side of object) and A” and C” nearly same, with highest value of 1 mR/hour and 0.93 mR/hour at standard tube voltage and at high kV technique obtained lower value of 0.29mR/hour and 0.25mR/hour.

Studi Efek Elektrooptis Pada Minyak Goreng

BERKALA FISIKA Vol 12, No 2 (2009): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

The aim of this research is to study differences between fresh palm oil and heated palm oil in the external static electric field. The external electric field used at this research was resulted from two parallel plates of 5 × 3 cm, separated by 2.5 cm and applied by high voltage from 0 to 11 kV. Light sources used here were red laser pointer (= 650 nm) and green laser pointer (= 532 nm) to measure change of polarization angle. The heated oil used here was fresh oil that was heated in circa 16 minutes. The results indicate that fresh oil has less average gradient of electro optic polarization (h) than heated oil, both of 650 nm and 532 nm. Theh’s value is measured more significant for = 532 nm than= 650 nm, and moreover can be used to measure the quality of oils based on fresh or polluted oil.        Keywords: palm oil, electrooptic, polarization.

Penentuan Konduktivitas Listrik dan Frekuensi Karakteristik Sel Ragi dengan Memanfaatkan Proses Dielektroforesis

Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal Vol 27, No 1 (2010)
Publisher : Fakultas Biologi | Universitas Jenderal Soedirman

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Abstract

Dielectrophorestic (DEP), a phenomenon where small particles such as yeast cells are manipulated by non-uniform electric fields. The net dielectrophoretic force is proportional to the polarisability of the cell and cause this cell moving toward higher field. By measuring velocity of the cell on the various frequency of the electric field, it can determine the electrical conductivity and the characteristic frequency of the yeast cells. The results showed that the conductivity of the yeast cell was (10,0 ± 0,4)10-9 Sm-1  and the characteristic frequency was 60 kHz.