Hydrodynamics of a turbulent fluidized bed is studied by means of the concurrent application of fiber optic sensors It is observed that in the vicinity of the column wall there is a high bubble activity region. Low bubble activity and A temperature increase from 22 to 145°C results in a more homogeneous turbulent fluidized bed with smaller bubbles Mass transfer coefficients between bubble-emulsion (kbe) and bubble-annulus (kh) are evaluated. The dominant mass and a helium tracer. negative bubble velocities are reported for the dense phase near the column centre-line region. and more gas flowing through an expanded dense bed emulsion phase.transfer path was the one from the bubbles to the annular region with kba being several times greater than kbe.On a etudi6 I'hydrodynamique d'un lit fluidise turbulent au moyen de I'application simultanee de capteurs a fibres On a observe dans la region de la paroi de la colonne une zone de forte activite de bullage. Une faible activite de bullage Une augmentation de la temperature de 22 a 145°C rend le lit fluidise turbulent plus homogene avec des bulles plus (Nakajima et al., 1991). Thus, there is limited data on turbulent fluidized beds operated at conditions other than room temperature. Studies at more elevated temperatures and relatively low superficial gas velocities were mainly concerned with the effect of temperature on minimum fluidization velocity and bed voidage (Otake et al., 1975; Mii et al., 1973;Sishtla et al., 1986). Reactor size, in most of these studies, was limited to bench scale or laboratory scale units (Kai and Furusaki, 1985;Yamazaki et al., 1986;Cai et al., 1988; Hatate et al., 1988; Rapagna et al., 1994).Modelling of fluidized beds requires the use of data from bubble sensors and tracers. Ege et al. (1999, in through a gate valve (V4). This valve was used to adjust the air flow. Air, before being fed to the fluidized bed, was heated using an electrical oven (0). Conditions of the preheated air were selected to adjust the fluidized bed reactor temperature. Air exiting the oven expanded into a plenum chamber,

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Lung imaging radiopharmaceuticals are helpful agents for measuring pulmonary blood flow and allow detection of pulmonary embolism and lung cancer. The goal of this study was to develop a novel potential radiopharmaceutical for lung imaging. Zolmitriptan (a selective serotonin receptor agonist) was successfully labeled with Tc via direct labeling method under reductive conditions studying different factors affecting the labeling efficiency.Tc-zolmitriptan was obtained with a maximum labeling yield of 92.5 ± 0.61 % and in vitro stability up to 24 h. Molecular modeling was done to predict the structure of Tc-zolmitriptan and ensure that radiolabeling did not affect binding ability of zolmitriptan to its receptor. Biodistribution studies showed that maximum lung uptake ofTc-zolmitriptan was 23.89 ± 1.2 % injected dose/g tissue at 15 min post-injection and retention in lungs remained high up to 1 h, whereas the clearance from mice appeared to proceed mainly via the renal pathway. Scintigraphic images confirmed the biodistribution results showing a high resolution lung image with low accumulation of radioactivity in other organs except kidneys and urinary bladder. Tc-zolmitriptan is not a blood product and so it is more safe than the currently availableTc-MAA, and its lung uptake is higher than that of the recently discovered I-IPMPD,Tc(CO)I and Tc-DHPM. So,Tc-zolmitriptan could be used as a hopeful radiopharmaceutical for lung scintigraphic imaging.

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Shaped fields are widely used in radiotherapy to protect critical organs and to avoid unnecessary normal tissue irradiation. The most common system for photon-beam shaping consists in a low-melting point alloy. The structure and the attenuation coefficient of normally casted Bi-Pb-Sn fusible alloys have been investigated. These normal casting fusible alloys have an adequate half-value layer and attenuation coefficient, as compared to lead metal. Also some physical properties of quenched Bi-Pb-Sn alloys have been studied and analyzed. These Bi-Sn-Pb quenched alloys have better mechanical properties, such as a high elastic modulus and hardness and a lower melting point. These advantages make Bi-Pb-Sn fusible alloys very important for radiotherapy shielding blocks and industrial applications with a reduced quantity of lead.