Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- ...Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.展开更多
Inorganic scintillators play an important role in detection and spectroscopy of gamma, X-rays and alpha particles as well as neutrons and charged particles. Scintillation crystals based on cesium iodide (CsI) are matt...Inorganic scintillators play an important role in detection and spectroscopy of gamma, X-rays and alpha particles as well as neutrons and charged particles. Scintillation crystals based on cesium iodide (CsI) are matters with relatively low hygroscopicity, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, pure CsI crystal and bromine doped CsI crystals were grown using the Bridgman technique. The concentration of the bromine doping element (Br) was studied in the range of 1.5 × 10-1 M to 10-2 M. The distribution of the doping element in the crystalline volume was determined by neutron activation. The result obtained with neutron activation analysis (NAA) has found that the mean values of Br found in grown crystals are consistent with those introduced in salt CsI, showing the incorporation of Br in the matrix structure of CsI. The optical transmittance assays were performed at a wavelength range of 110 nm to 1100 nm. Analyses were carried out to evaluate the developed scintillators, concerning alpha particles and gamma radiation.展开更多
文摘Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.
文摘Inorganic scintillators play an important role in detection and spectroscopy of gamma, X-rays and alpha particles as well as neutrons and charged particles. Scintillation crystals based on cesium iodide (CsI) are matters with relatively low hygroscopicity, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, pure CsI crystal and bromine doped CsI crystals were grown using the Bridgman technique. The concentration of the bromine doping element (Br) was studied in the range of 1.5 × 10-1 M to 10-2 M. The distribution of the doping element in the crystalline volume was determined by neutron activation. The result obtained with neutron activation analysis (NAA) has found that the mean values of Br found in grown crystals are consistent with those introduced in salt CsI, showing the incorporation of Br in the matrix structure of CsI. The optical transmittance assays were performed at a wavelength range of 110 nm to 1100 nm. Analyses were carried out to evaluate the developed scintillators, concerning alpha particles and gamma radiation.
