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RY cam yıldızının tayf analizi
R Y Cam, M3IIIvar tayf ışınım değişim dönemi yaklaşık 134 gün olanSRb türü bir yarıdüzenli değişen yıldızdır. Hipparcos Kataloğu RY Cam `ın, 0.16açısaniyesi ötede bir astrometrik bileşeni olduğunu belirlemiştir. Daha önce RTT150'yetakılan Coravel fotoelektrik hızmetre ile Vilnius Üniversitesi ile yürütülen projesırasında (J. Sperauskas, Z. Aslan, S. Bartasiute, R.P. Boyle, Baltic Astronomy, Vol.11,465, 2002) RY Cam'da, radyal hız değişimi görülmüştür.B u çalışmamda Vega yıldızının gözlem verilerinin eçhelle tayfının IRAFprogramıyla indirgenmesine yer verdim ki devamında benzer şekilde üzerinde çok fazlaçalışma yapılmamış olan RY Cam yıldızının gözlem verilerinin echelle tayfının IRAFprogramıyla indirgenmesini inceleyeceğim.
Design and construction of a toolbox for measurements of light and temperature
In this study, a simple toolbox containing a digital lux meter and a digital thermometer has been constructed. Two different light sensors, a photo-resistor and a photo-transistor, and a well calibrated temperature sensor are used. Light sensors are calibrated against a reference photometer. The optical and thermal data are acquired by means of Arduino Uno and measurement results are printed on an LCD screen. In addition a Graphical User Interface using MATLAB has been developed to analyze and visualize the illumination and temperature data in desired time interval.
Investigation of thermal quenching and fading characteristics of Eu doped CaMoO4
In this thesis, the heating rate effect on the dose response and TL glow curves of CaMoO4:Eu+3 have been investigated by using the supralinearity function, f(D). The dose response functions have been evaluated using the total areas at different heating rates between 1 oC.s-1 and 10 oC.s-1. The results of this work have showed that, the curves have linear (f(D)=1) behavior at very low doses then they are supralinear (f(D)>1) up to nearly 102 Gy, after this dose level the peaks saturate and go into sublinear (f(D)<1) region the heating rates of 1 oC.s-1, 2 oC.s-1, 3 oC.s-1, 5 oC.s-1, 6 oC.s-1 and 10 oC.s-1. But the curves show very different behavior at heating rates of 4 oC.s-1. They show linear (f(D)=1) behavior nearly up to 100 Gy, and after this dose level the peaks suddenly saturates and goes into sublinear (f(D)<1) region. Also the temperatures of all peaks are shifted higher temperatures and the integrated peak area of the curves decreases by about 15 % as the heating rate increases as expected in theory because of the thermal quenching effect.
Evropyum katkili CaMoO4'ün sentezlenmesi ve termolüminesans özellikleri
Rare-earth ion doped calcium molybdate (CaMoO4) has attracted much interest due to its wide luminescence applications. These include optical filters, solid state lasers, LED (light emitting diodes), scintillators, microwave dielectrics, cryogenic detectors and fluorescent lamps. Moreover, some of its attractive features include a high melting point (1445–1480 oC), refractive index (1.98), effective average decay time (14 µs), photo electron yield (9%) and it is also chemically resistant and non-hygroscopic. CaMoO4 shows a broad blue and/or green luminescence emission peak in the range 350–650 nm with a peak maximum around 500 nm. In the given study Eu doped Calcium Molybdate phosphors have been sythesized using the complex polymerization method (cpm) and the thermoluminescence properties were investigated in detail. Computerized glow deconvolution (CGCD) method was used to determine the kinetic parameters namely the order of kinetics (b), activation energy (Ea) and the frequency factor (s) associated with the dosimetric thermoluminescent (TL) glow peaks of CaMoO4: Eu after different dose levels with β irradiation.
Calculation of alpha half-lives of radiosotopes by using different techniques
AbstractCalculation of Alpha Half-Lives of Radioisotopes byUsingDi¤erent TechniquesSÜR, SerapM. Sc in Engineering PhysicsSupervisor: Prof. Dr. Zihni ÖZTÜRKJuly 2005The estimations and comparisions of alpha half-lives of alphaemitting isotopes of odd-odd, even-even, odd-even and even-odd nu-clei are made by using di¤erent methods. Tunnelling probabilitiesare determined by the breaking the Coulomb barrier into segments.The obtained succesive tunnelling probabilities are multiplied toobtain tunnelling probability utilized to determine alpha half-lives.The advantages and disadvantages of the model are discussed. Itis observed that an application of the simple model based on thetunnelling probability provides quite satisfactory results comparedto some other techniques.Key words: Alpha Decay, Tunnelling Probability, Half-life.1
Investigation of thermoluminescence properties of calcite
ABSTRACTInvestigation of ThermoluminescenceProperties of Calcite (CaCO3)GÜN EsenM.Sc., in Physics EngineeringSupervisor: Assist. Prof. Dr. R.Güler YILDIRIMFebruary 2006, 65 pagesThe thermoluminescence characteristics of calcite samples of annealedand unannealed has been studied that were beta irradiated at different dose levelsin this study. The additive dose (AD), variable heating rate (VHR), initial rise(IR), computer glow curves deconvolution (CGCD) and peak shape (PS) methodshave been used for the evolution of TL glow peaks. These methods were used todetermine the number of peaks and kinetic parameters (activation energy E,attempt-to-escape frequency factor s and kinetic orders b). The calcite samplesthat were collected from Gaziantep city exhibit two main TL peaks following βirradiation between the dose levels 0.9 Gy and 864 Gy. The results indicate thatkinetic parameters that obtained vary fairly from the different methods. The glowcurves of annealed and unannealed sample irradiated with beta dose show mainpeaks at (115 and 254 0C). The enhancement in TL sensitivity was found to bedepending on the annealing temperature and time. The measurement of the doseresponses and fading process are very useful in radiation dosimetry andarcheological dating. The dose response of all peaks have shown a similar pattern.First they follow strong linearity and then saturate at different dose levels. Afterthe storage at room temperature for four weeks, peak 1 was completelydisappeared from the glow curves, but peak 2 was not affected during this period.Peak 1 is reduced to typically 36% of its original value at the end of 2 hours and70% its original value at the end of 6.5 hours. The glow curve structure of calcitewas also studied by additive dose method in this study and it was observed that itsglow curve is the superposition of at least two first order glow peaks.Keywords: thermoluminescence, annealing, unannealing, kinetic parameters,calcite.