clay minerals are considered the most important components of clastic reservoir rock evaluation studies. the shurijeh gas reservoir formation, represented by shaly sandstones of the late jurassic-early cretaceous age, is the main reservoir rock in the eastern kopet-dagh sedimentary basin, ne iran. in this study, x-ray diffraction (xrd), x-ray fluorescence (xrf), scanning electron microscopic (s...

Introduction: Crosstalk is a leakage of X-ray or light produced in a matrix of X-ray detectors or array of photodiodes in one element to other elements affecting on image contrast and spatial resolution. In this study, we assessed X-ray crosstalk in a computed tomography (CT) scanner with small detector elements to estimate the effect of various parameters such as X-ray tube voltage, detector e...

Introduction Radiation exposures from diagnostic medical examinations are generally low and are almost always justified by the benefits of accurate diagnosis of possible disease conditions. Therefore, entrance skin dose (ESD), body organ dose (BOD), and effective dose (ED) from adult patients undergoing routine thorax posterior-anterior (PA) and thorax right lateral (RLAT) were estimated in Uni...

Background: Panoramic imaging is one of the most common imaging methods in dentistry. Regarding the side-effects of ionizing radiation, it is necessary to survey different aspects and details of panoramic imaging. In this study, we compared the absorbed x-ray dose around two panoramic x-ray units: PM 2002 CC Proline (Planmeca, Helsinki, Finland) and Cranex Tome (Soredex, Helsinki, Finland).<br ...

Coronal cavities are regions of low coronal emission that usually sit above solar prominences. These systems can exist for days or months before erupting. The magnetic structure of the prominence-cavity system during the quiescent period is important to understanding the pre-eruption phase. We describe observations of a coronal cavity situated above a solar prominence observed on the western li...

Recent calculations of atomic data for Fe XV have been used to generate theoretical line ratios involving n = 3–4 transitions in the soft X-ray spectral region (∼52–83Å), for a wide range of electron temperatures and densities applicable to solar and stellar coronal plasmas. A comparison of these with solar flare observations from a rocket-borne spectrograph (XSST) reveals generally good agreem...

We have obtained spectra for 1273 stars using the 0.9m Coudé Feed telescope at Kitt Peak National Observatory. This telescope feeds the coudé spectrograph of the 2.1m telescope. The spectra have been obtained with the #5 camera of the coudé spectrograph and a Loral 3K X 1K CCD. Two gratings have been used to provide spectral coverage from 3460 Å to 9464 Å, at a resolution of ∼1Å FWHM and at an ...