background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

We present an improvement of the titration method for binding constant determination with electrospray ionization (ESI) mass spectrometry that is unaffected by differences in ESI response of measured species in solution. The method consists of a calibration and titration, both using an internal standard that allows relative quantitation. This avoids artifacts such as a decrease in overall signa...

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, etc. We report on recent work showing how well multi-scale measurements of the anisotropy power spectrum can resolve these factors. We identify a hypersurface in cosmic parameter...

The separation distances between the pressure, the luminous, the ionization and the current front in a magnetically driven shock tube were investigated under discharge conditions of constant voltage and variable pressures. In order to achieve a steady-state, one-dimensional flowparallelplate electrodes and a constant voltage energy source were chosen, onventional magnetic probe and piezo-electr...

The measurements of the overall bicyclic peroxy radical + NO rate constant for the 1,3,5-trimethylbenzene (1,3,5-TMB) system and of the nitrate product yields for the benzene, toluene, p-xylene, and 1,3,5-TMB systems were performed via the turbulent flow chemical ionization mass spectrometry technique. While the overall rate constant was found to be consistent with the value used in the most de...

Bell’s palsy is an idiopathic peripheral nerve palsy involving the facial nerve. It accounts for 60 to 75% of all cases of unilateral facial paralysis. The main mechanisms to induce BP remain unclear, but infection, ischemic condition and immunodeficiency may contribute to the development of Bell’s palsy. Accumulating evidence has shown several factors can trigger the reactivation of latent...

background: the effectiveness and safety of brachytherapy treatment is mainly concerned with the calibration of sources and their traceability to internationally accepted standards. secondary standard dosimetry laboratory (ssdl) does not offer calibration of ionization chambers with gamma-ray spectrum of high dose rate source 192ir . this work has been carried out to calibrate the high dose rat...

We discuss the method of field strength calibration from energy distributions measurements of free space field ionization. An alternative approach is considered and an improved calibration is suggested. The method of electric field strength calibration from considerations of energy distribution of field ionization in free space above a field ion emitter tip is due to Sakurai and Muller [1,2]. U...

The effect of polymer chalge density on the interaction of tetradecyltrimethylammonium brolnide <TrAB) with poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA) has been investigated usmc a surfactant-sensitive solid-state membrane electrode. The experimental results indi~te that the intenction with PAA begins at about the same equilibrium TTAB concentration wben the degree of ionization (...

The single ionization of inner-shell bound electrons by lepton impact is a fundamental atomic process of particular interest. Recently, essential progress has been achieved in fragmentation experiments due to developments in many-particle imaging techniques, so-called reaction microscopes [1]. The measurements of the multiply differential cross sections become now feasible. We have deduced the ...