Eight new photochromic dihydro 5-azaindolizine-linker-conjugates with a terminal ethylene anchoring group have been synthesized via palladium-catalyzed Negishi coupling. Polychromatic light irradiation of the photochromic dihydro 5-azaindolizines (DHAIs) led to ring-opened colored betaines which underwent reversible thermal 1,5-electrocyclization into their corresponding DHAIs in the second domain. The noteworthy multiaddressable photochromic properties are useful for a plethora of new applications for these materials such as anchoring the ethylene group to metal-oxide nanoparticles.

The superiority of silver-doped titania for photocatalytic oxidation (PCO) of organic compounds inspired us to investigate PCO of 1,2-cyclohexanediol. Ag/TiO2 was prepared, characterized (nanosize 19–24 nm) and used for oxidation of 1,2-cyclohexanediol (1) in acetonitrile. The photolysate was analyzed using GC and GC/MS techniques. The PCO products are 2-hydroxylcyclohexanone (2), 1,2-cyclohexandione (3), 2-cyclohexenone(4), cyclohexanone (5), and adipic acid (6).The formation of electron–hole pair at the surface of the catalyst followed by oxidation reactions was the suggested mechanism. Kinetic studies revealed first-order mechanism for PCO of 1 and rate constant (k) =
0.145 h–1. Copyright © 2012 John Wiley & Sons, Ltd.

The superiority of silver-doped titania for photocatalytic oxidation (PCO) of organic compounds inspired us to investigate PCO of 1,2-cyclohexanediol. Ag/TiO2 was prepared, characterized (nanosize 19–24 nm) and used for oxidation of 1,2-cyclohexanediol (1) in acetonitrile. The photolysate was analyzed using GC and GC/MS techniques. The PCO products are 2-hydroxylcyclohexanone (2), 1,2-cyclohexandione (3), 2-cyclohexenone(4), cyclohexanone (5), and adipic acid (6).The formation of electron–hole pair at the surface of the catalyst followed by oxidation reactions was the suggested mechanism. Kinetic studies revealed first-order mechanism for PCO of 1 and rate constant (k) =
0.145 h–1. Copyright © 2012 John Wiley & Sons, Ltd.

The superiority of silver-doped titania for photocatalytic oxidation (PCO) of organic compounds inspired us to investigate PCO of 1,2-cyclohexanediol. Ag/TiO2 was prepared, characterized (nanosize 19–24 nm) and used for oxidation of 1,2-cyclohexanediol (1) in acetonitrile. The photolysate was analyzed using GC and GC/MS techniques. The PCO products are 2-hydroxylcyclohexanone (2), 1,2-cyclohexandione (3), 2-cyclohexenone(4), cyclohexanone (5), and adipic acid (6).The formation of electron–hole pair at the surface of the catalyst followed by oxidation reactions was the suggested mechanism. Kinetic studies revealed first-order mechanism for PCO of 1 and rate constant (k) =
0.145 h–1. Copyright © 2012 John Wiley & Sons, Ltd.

The superiority of silver-doped titania for photocatalytic oxidation (PCO) of organic compounds inspired us to investigate PCO of 1,2-cyclohexanediol. Ag/TiO2 was prepared, characterized (nanosize 19–24 nm) and used for oxidation of 1,2-cyclohexanediol (1) in acetonitrile. The photolysate was analyzed using GC and GC/MS techniques. The PCO products are 2-hydroxylcyclohexanone (2), 1,2-cyclohexandione (3), 2-cyclohexenone(4), cyclohexanone (5), and adipic acid (6).The formation of electron–hole pair at the surface of the catalyst followed by oxidation reactions was the suggested mechanism. Kinetic studies revealed first-order mechanism for PCO of 1 and rate constant (k) =
0.145 h–1. Copyright © 2012 John Wiley & Sons, Ltd.

LaBr3:Ce scintillating detectors exhibit excellent properties for γ-ray spectroscopy such as high energy resolution and operation under room temperature as well as MHz counting rates. On the other hand, sever background radiations exist due to the internal contamination of radioactive materials that are very difficult to be avoided during the manufacture. To decrease the effect of these background levels, some analytical techniques, e.g. background subtraction, should be applied. In the present work, we investigate the efficiency of the sensitive nonlinear iterative clipping peak (SNIP) method for background estimation and subtraction. Optimization of the clipping window is discussed for range of energy up to 3 MeV. Enhancement of energy resolution up to 50% was obtained.

LaBr3:Ce scintillating detectors exhibit excellent properties for γ-ray spectroscopy such as high energy resolution and operation under room temperature as well as MHz counting rates. On the other hand, sever background radiations exist due to the internal contamination of radioactive materials that are very difficult to be avoided during the manufacture. To decrease the effect of these background levels, some analytical techniques, e.g. background subtraction, should be applied. In the present work, we investigate the efficiency of the sensitive nonlinear iterative clipping peak (SNIP) method for background estimation and subtraction. Optimization of the clipping window is discussed for range of energy up to 3 MeV. Enhancement of energy resolution up to 50% was obtained.

Active interrogation in 235U was demonstrated with LaBr3:Ce scintillation detectors using the nuclear resonance fluorescence (NRF) technique. An NRF experiment was performed at the High Intensity y-ray Source (HlyS) facility using quasi-monochromatic circularly or linearly polarized y-ray beams. Photons scattered at 90o relative to the incident beam were detected with two different sizes of cylindrical LaBr3:Ce detectors. Clear NRF peaks at 1733 and 1815 keV corresponding to de-excitations to the ground state and/or low-lying levels in 235U were observed within 77 minutes of beam time even under the high background due to the self-activity of LaBr3:Ce and the radioactive decay of 214Bi nuclei existing in the 235U target. The present study shows a possibility of using LaBr3:Ce detector to perform NRF experiments, promoting many options for inspection of special nuclear materials.

Active interrogation in 235U was demonstrated with LaBr3:Ce scintillation detectors using the nuclear resonance fluorescence (NRF) technique. An NRF experiment was performed at the High Intensity y-ray Source (HlyS) facility using quasi-monochromatic circularly or linearly polarized y-ray beams. Photons scattered at 90o relative to the incident beam were detected with two different sizes of cylindrical LaBr3:Ce detectors. Clear NRF peaks at 1733 and 1815 keV corresponding to de-excitations to the ground state and/or low-lying levels in 235U were observed within 77 minutes of beam time even under the high background due to the self-activity of LaBr3:Ce and the radioactive decay of 214Bi nuclei existing in the 235U target. The present study shows a possibility of using LaBr3:Ce detector to perform NRF experiments, promoting many options for inspection of special nuclear materials.

A nuclear resonance fluorescence (NRF) experiment was performed on a 235U target with quasi-monochromatic γ-rays at the High Intensity γ-ray Source (HIγS) facility using a 1733 keV resonant energy. A LaBr3(Ce) detector array consisting of eight cylindrical detectors, each with a length of 7.62 cm and a diameter of 3.81 cm, was implemented in this measurement. Moreover, a high-purity germanium (HPGe) detector array consisting of four detectors, each of which has a relative efficiency of 60%, was used as the benchmark for the measurement taken using the LaBr3(Ce) detector array. The integrated cross section of the NRF level, measured with LaBr3(Ce) detectors, showed good agreement with the available data.