Papers by Keyword: Irradiation

Abstract: This research paper suggests a possible solution for a growing problem of irradiated materials ́ waste processing. Recycled radiation crosslinked polyamide 6 (rPA6_x) was used as a filler into non-modified polyamide 6 (PA6) in several concentrations. Influence of the amount of the filler on mechanical properties of resulting blends was investigated. Tensile test was carried out at two temperatures to determine mechanical behavior. Results show that there is a little difference at all observed material characteristics in comparison with non-modified PA6. According to the results it was proven that there is a possible utilization of such modified materials after the end of their service life but some other properties have to be examined.

Abstract: In this paper, the effect of the electron beam irradiation on the indentation hardness, indentation modulus and indentation creep have been studied by means of the Depth sensing indentation (DSI). Cross-linking is a process in which polymer chains are associated through chemical bonds. Radiation doses of 33, 66 and 99 kGy were used for unfilled polyamide 6 with the 7% crosslinking agent (triallyl isocyanurate). Beta irradiation of the examined thermoplastic caused the growth of values of material parameters as micro-hardness, indentation modulus or indentation creep etc. From this point of view, there may be new application in areas with mechanical properties higher than their original properties. This study compared the mechanical properties of irradiated and non-irradiated PA6.

Abstract: According to the characteristics of high altitude and strong ultraviolet radiation in Tibet, this paper do ultraviolet irradiation experiment research to different strength grades of concrete blocks in a closed laboratory, it is found that ultraviolet rays has promoting effect to early strength growth of test block, but the growth became slow along with the time.

Abstract: The influence of additives on the radiation stability of the concrete will occur through the influence of radiation changes of hardened cement paste on radiation changes of concrete and can be quite significant. The test sequence was produced according to the modified method described in case [11]. The samples were prepared in the form of prisms with the following dimensions: 10 mm x 10 mm, 30 mm. Measurement series were produced after each heating and cooling sequence. Then the difference between the values before and after heating was calculated.

Abstract: The results of the study on hydrogen diffusion through the metal membranes in the process of electrolytic hydrogenation and electron irradiation (energy of 40 keV , the current density is from 3 to 30 mA ) have been presented. It has been established that hydrogen release time from the membrane is determined by the parameters of the electron beam and its duration, and depends on the structure and the phase state of the metal membrane. The analysis of the hydrogen release time was done on a mass spectrometer connected to a vacuum chamber containing an electron gun and an electrolytic cell. The hydrogen diffusion coefficients when exposed to an electron beam were 2-3 times higher than under the same conditions without the electron beam irradiation. The results can be used in the technology of manufacturing of new materials with desired properties.

Abstract: I-V-characteristics of an irradiated transistor in many cases should be measured inside the radiation chamber with long cables, which introduces noticeable measurement error. In this paper IV-characteristics of an irradiated bipolar junction transistor measured with the 4-wire and the 2-wire circuits are presented and compared to direct (without cables) measurements. Significant enlargement of measurement error for the 2-wire method in comparison with the 4-wire method is shown for different currents.

Abstract: Ultraviolet light has been considered a main factor of natural aging threats the oil sealing’s lifetime when using outdoor. In this work, we will compare the behavior of NBR (the mostly used material for sealing) during UV aging. To analyze the characteristics of UV irradiation behavior of NBR,their surface morphology and infrared spectroscopy were measured,after the irradiated at UV environment for period time. The results showed that the surface of rubber occur more white spots and the aging began occurred.

Abstract: Surface modified ELISA plates grafted with methylacrylic acid (MAA) were prepared by ⁶⁰Co γ-Ray irradiation at room temperature in MAA water solution. The optimum conditions of modification were decided by the water contact angle and the absorbency of polystyrene enzyme label plate. FTIR, XRD spectra and AFM images show that MAA and its polymer have been grafted to the surface of the ELISA plates induced by ⁶⁰Co γ-Ray irradiation. The volume concentration of MAA aqueous solutions reached 10%, and the radiative intensity was 10kGy, and correspondingly, the content of carboxyl group on the surface of ELISA plates reached 0.30mmol/cm².

Abstract: Little research was done to investigate possible utilization of irradiated materials after the end of their lifetime. This research paper deals with the possible utilization of irradiated high-density polyethylene (HDPEx) after its service life. Irradiated HDPE was used as filler into the virgin low-density polyethylene (LDPE). Three material combinations were investigated (powder/powder, granules/powder and granules/grit) and influence of the filler on optical behavior was measured. Terahertz spectroscopy at wide range of frequencies was used for refractive index determination. According to measured data there is significant influence by the amount of the filler. Moreover influence of particle size was also observed. All three combinations have similar curve courses; however the most consistent results were achieved at the powder/powder combination. Behavior of virgin LDPE and virgin HDPE is in correlation with previous findings.

Abstract: This research paper deals with utilization of recycled irradiated high-density polyethylene (HDPEx). Grit prepared of irradiated HDPEx was used as a filler into virgin low-density polyethylene (LDPE). Concentrations from 10 to 60 % were made and their influence on mechanical properties was investigated. Tensile test at ambient and elevated temperature was used to describe mechanical properties of resulting blends. Results show that there is an upward trend of elastic modulus and ultimate tensile strength and downward trend of nominal strain at ambient temperature. Similar findings were observed at elevated temperature, which might suggest possible utilization of such modified thermoplastic materials. However other material properties have to be tested to make final conclusion.