Browsing by Author "Koc, Kemal"

Now showing 1 - 4 of 4

Direct Determination of Radiation Dose in Human Blood
(2016) Tamir, A.Gunes; Gulec, Ozge; Sahiner, Eren; Bolukdemir, Mustafa H.; Koc, Kemal; Meric, Niyazi; Keles, Sule K.
In this work, it has been shown that it is possible to determine the radiation doses in human blood exposed to internal or external ionizing radiation treatment, both directly and retrospectively. OSL counts from the waste blood of a patient injected with a radiopharmaceutical for diagnostic or treatment purposes and from a blood sample having a laboratory-injected radiation dose were both used for measurements. The dose values obtained the bloods were found as similar to 0.46 Gy for the 1-5Gy dose range and as similar to 0.51 Gy for the 0.143-0.858 Gy dose range using the optically stimulated luminescence technique. The blood aliquots from a healthy person were exposed to different external laboratory doses. The dose values corresponding to a 10Gy laboratory dose from the aliquots exposed to external radiation were found as 10.94 +/- 3.30 Gy for Disc 3 and 10.79 +/- 3.28 Gy for Disc 1. This study shows that the dose received by a person can be measured simply and retrospectively, using only a very small amount of blood. The results may have important ramifications for the medicine and healthcare fields in particular.
Investigation of Interactions Between Low Energy Positrons and DNA Using the Monte-Carlo Method
(2015) Cetin, Ahmet; Koc, Kemal
Positron Emission Tomography (PET) is the imaging system used to diagnose an illness. Positrons from a radioactive nucleus are injected into the patient. There are few existing papers on the energy loses of positrons especially with low energy in the biological target. So, in this study, the goal was to investigate how low kinetic energy positrons (20eV-10keV) interact with DNA by using the Monte-Carlo simulation. In the simulation, screened Rutherford scattering Formula where Wentzel screening parameter was used for elastic collisions, algorithm proposed for the electron-matter interactions of re-edited version of positron interaction was used for inelastic collisions. Because positron-matter interaction involves randomness, the simulation was done using the Monte Carlo Method. In this simulation the screened Rutherford scattering formula using Wentzel screening parameters for elastic collisions and the electron-matter interaction model suggested by Liljequist for inelastic collisions were rearranged in order to determine positron interaction. The stopping powers of adenine, guanine, thymine, cytosine compounds and DNA were determined and compared with that of other related results. The results were found to be considerably higher than reported in some other papers.
Kinetic Study on the OSL Technique Using Human Blood Sample
(2018) Koc, Kemal; Tanir, Gunes; Aksoy, Gulper; Bolukdemir, M. Hicabi
It is dear that humans are exposed to ionizing radiation both of internally or externally in radiotherapy. The determination of ionizing radiation dose in human blood has been previously performed by us using optically stimulated luminescence technique. OSL technique is based on measuring the luminescence intensity from a sample that has been exposed to ionizing radiation. In this study, the detrapping constants for human blood samples were investigated using Curve-Fitting, Active OSL-Approximation and Linear Modulation techniques. The Active OSL-Approximation was based on the radioactive decay law of successive disintegration. It allows obtaining the peak forms of luminescence signal. It has been observed that the decay rates for blood sample exposed to different radiation doses were changed with dose. AOSL- Approximation is appropriate for separating the peaks that correspond to decay rates.
Measurement of The Distribution of Radiation in The Area Surrounding The Target Mass Using Optically Stimulated Luminescence Technique
(2017) Tanir, A. Gunes; Yedek, Hatice; Koc, Kemal; Bolukdemir, M. Hicabi; 27829183
The scattered doses received by the area surrounding the target that has been subjected to x-rays were investigated. Two experiments were carried out: 1-Al2O3: C was used as dosimeter and the luminescence counts was measured using both the RisO TL/OSL system and an ion chamber. 2- BeO aliquots were used and the counts were read using the IBEOX/OSL system. According to the results, the doses absorbed by the area surrounding the target are significantly amount.