[en] Turkey's strategic location makes it a natural 'energy bridge' between major oil producing areas in the Middle East and Caspian Sea regions on the one hand and consumer markets in Europe on the other. Natural gas is the fastest growing primary energy source in the world. Worldwide gas use more than doubles in the reference case projection, reaching 4.92 trillion cubic meters in 2020 from 2.32 trillion cubic meters in 1996. Current gas production in Turkey meets 2.8% of domestic consumption requirements. Turkish natural gas is projected to increase dramatically in coming years, with the prime consumers expected to be industry and power plants. Turkey has chosen natural gas as the preferred fuel for the massive amount of new power plant capacity to be added in coming years. (author)

[en] A simple and fast technique of micro gel electrophoresis of single cells (DNA Comet Assay) was used to detect DNA comets in irradiated quail meat samples. Quail meat samples were exposed to radiation doses of 1.05, 2.00 and 4.00 kGy in gamma cell (Gamma cell ⁶0Co, dose rate 1.31 kGy/h) covering the permissible limits for enzymatic decay and stored at 4 degree C. The cells isolated from muscle (chest, thorax) in cold PBS were analysed using the DNA comet assay on 1, 4, 8 and 11 day post irradiation. The cells were lysed between 2, 5 and 9 min in 2.5% SDS and electrophoresis was carried out at a voltage of 2 V/cm for 2 min. and then prospidium iodide staining was employed to visualize DNA. After prospidium iodide staining, the slides were evaluated through a fluorescent microscope (Olympus BX 51 model with florescence and DIC attachments). In all irradiated samples, fragmented DNA stretched towards the anode and damaged cells appeared as a comet. The density of DNA in the tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short tails only.

[en] Escherichia coli O157:H7 was conclusively identified as a pathogen in 1982 following its association with two food-related outbreaks of an unusual gastrointestinal illness. The infectious dose of E. coli O157 is very low, and as a result the organism can be transmitted efficiently not only via contaminated foods but also person to person (Doyle 1991, Karch et al. 1996). Although not definitely linked, consumption of undercooked meats and mainly hamburgers has been strongly implicated in hemorrhagic uremic colitis and hemolytic uremic syndrome. Water and unpasteurized milk are also recognized as sources of outbreaks (Yu and Bruno 1996 , Venkateswaran et al. 1997). Meat and milk products are the most important foods for E. coli O157:H7 outbreaks. Apple cider, drinking and swimming waters are also important for outbreaks. Literature reveals that E. coli O157:H7 is not resistant to the application of radiations. Gamma rays obtained from ''6''0Co ve ''1''3''7Gs sources find wide application in the food protection as these rays eliminate various pathogen including E.coli O157:H7 in the solid foods. Irradiation of food is less effective at temperature below freezing point. In USA beef is allowed to prevent E.coli O157:H7 infection (Farkas et al.1998;Fujikawa et al.1992; Harewood et al.1994;Park et al.1999)

[en] To inhibit Escherichia coli O157:H7 and determine a indicator bacteria for irradiation procedure in minced meat, this study evaluated increased irradiation doses on five strains of each of the following bacteria: 5 strains E. coli type 1 and 4 strains E. coli O157:H7. E. coli type 1 mixture was added into the mixed in ratio 1:100000 of E. coli type l to samples and E. coli O157:H7 mixture was added into the mixed in five different ratios namely 1:10, 1:100, 1:1000, 1:10000, 1:100000 of E coli O157:H7 in the minced meat. A range of irradiation doses from 1 kGy to 4 kGy was investigated for the inhibition of E. coli O157:H7 and the resistance of E. coli type 1 to irradiation. After irradiation, E. coli O157:H7 and E. coli type 1 were counted in the irradiated minced meat by using MPN techniques. D₁₀ values of each bacteria were be measured as 0.3 kGy and 0.55 kGy for E. coli 0157:H7 and E. coli type 1 respectively. This study showed that 1.5 kGy irradiation can inactivate 10⁵ g/O157:H7 serotype and 10³ g / E. coli type 1, this inactivation level is adequate for safety consumption of minced meat such as hamburger even if undercooking conditions. Increased irradiation doses were the most effective on E. coli O157:H7. The results show that E. coli type 1 is more resistant to than E. coli O157:H7 and other natural non-Pathogenic cohabitant bacteria and E. coli type 1 is an adequate indicator for the efficiency of irradiation against to O157:H7 serotype in minced meat

[en] In this study, the various dosimetric properties of the thermoluminescent (TL) phosphor of CaF₂:natural including response characteristics, sensitivity to thermal annealing and decay of stored energy were investigated in detail. The analysis of the peak temperature values and the half widths of the resolved components in the glow curves, by using the Computerized Glow Curve Deconvolution (CGCD) Method, resulted in the activation energy (E) of 0.85–1.83 eV and frequency factor (s) of 6.17E+9–2.90E+15 s⁻¹. The effects of pre-irradiation thermal annealing on the radiation-induced sensitization of the thermoluminescent response of CaF₂:natural were presented. An enhancement of sensitivity after being subjected to a high beta particle exposure was clarified. The effect was complicated by the influence of heat treatments before the exposure to radiation. Replicate runs on CaF₂:natural after irradiation with 1 Gy absorbed dose indicated good reproducibility of peak temperatures and intensities; they can be re-used for repeated measurements. It appeared that the main dosimetric peak at 280 °C exhibits negligible fading over 4 weeks and may be used for dosimetry. This study has demonstrated that the potential exists for the use of CaF₂:natural for TL radiation dosimetry.

[en] The characteristics of natural calcium fluoride from Cicekdagi Massif (Akcakent) in Turkey have been studied by analysing its thermoluminescence glow curve structure between 30 and 450 deg. C for the purpose of radiation dosimetry. A variety of thermoluminescence measurement regimes have been examined to determine the most effective and appropriate annealing temperature, heating rate and dose range for the proper and accurate use of this phosphorescent material. After a high temperature annealing as TL readings, optimum values for low temperature annealing and heating rate were obtained as 60 deg. C for 24 h and 1 deg. C s^-1, respectively. In the dose range of 0.5 Gy-1 kGy, the intensity of individual glow peaks and overall glow curve shape changed. The peak intensities of all glow curves located at 100 and 120 deg. C (overlapping considerably), and at 215 deg. C, at 310, 350 and 410 deg. C (overlapping) increase linearly with increasing ionizing radiation over a range of from 0.5 Gy to 10 Gy.