Studies on mechanical, thermal and morphological properties of irradiated recycled polyamide and waste rubber powder blends

The aim of this article was to show the effect of gamma irradiation on mechanical and thermal properties of recycled polyamide (rPA) copolymer blended with different content of waste rubber powder (WRP). In order to study the structural modifications of prepared blends have been subjected to irradiation doses up to 200 kGy were applied to all samples. Non-irradiated blends were used as control samples. Mechanical properties, namely, tensile strength (TS), elastic modulus, elongation at break and hardness have been followed up as a function of irradiation dose and degree of loading with rubber content. Furthermore, the influence of radiation dose in the thermal parameters, melting temperature, heat of fusion, ΔH_f of the recycled PA and its blend with waste rubber powder (WRP) was also investigated.     

Effect of absorbed dose and storage length on electron paramagnetic resonance （EPR） signal strength in irradiated alfalfa seeds

1 Introduction Human salmonellosis associated with the con- sumption of alfalfa seed sprouts has been documented in several countries and people have applied several techniques to kill microorganisms in the alfalfa seeds[1]. Gamma irradiation can effectively kill the microorganisms in the seeds over a certain range of absorbed dose[2]. As a prerequisite, a suitable detection method for distinguishing whether or not a kind of food has been irradiated lies not only in whether some differences be…     

Thermal, structural and mechanical properties of neutron irradiated Bayfol nuclear track detector

Samples from sheets of the polymeric material Bayfol have been exposed to neutrons of incident energy in the range 0.8-19.2 MeV. The resultant effect of neutron irradiation on the thermal properties of Bayfol has been investigated using thermo-gravimetric analysis. The onset temperature of decomposition and activation energy of thermal decomposition were calculated. The variation of transition temperatures with neutron energy has been determined using differential thermal analysis. The results indicate Bayfol thermograms characterized by the appearance of an endothermic peak due to melting. Melting temperature was found to be dependent on the neutron energy. Structural property studies using infrared spectroscopy were performed and results indicated that scission takes place at the carbonate site with the formation of a hydroxyl group. Mechanical properties were studied and it is shown that, at the fluence range 0-4.4 MeV, the standard chains and a great number of chain ends weaken and the material may become softer.     

Characteristics of pulsed photo-stimulated luminescence and thermoluminescence for the identification of gamma irradiated poultry eggs

Pulsed photo-stimulated luminescence (PPSL) is a simple screening method that can be employed qualitatively at the spot for the detection of eggs treated with ionizing radiation.Due to the variations in the results during storage,the eggs of ostrich,duck,hen,and quail were irradiated to doses of 0,1,2,and 3 kGy.Most of the samples were incorrectly identified during storage after four months of irradiation.Thermoluminescence (TL) technique was also tried by using egg shells in order to confirm the irradiation treatment in eggs.TL glow curves were recorded between the temperatures 50℃to 400℃at the rate of 5°/s for all the control and irradiated samples.On the basis of integrated areas of first glow curves (TL1),the glow curve ratios (TL1/TL2) and the shapes of maxima of TL1, the irradiation treatment of all the eggs was confirmed.Furthermore,the presence of calcite and aragonite minerals that cause the TL signal in the egg shells were studied using X-ray diffraction spectrometry.     

Investigations on the structural and optical properties of the swift heavy ion irradiated 6HSiC

Single crystal 6HSiC wafers have been irradiated with 150 MeV Ag¹²⁺ ions with fluences ranging from 1 × 10¹¹ to 1 × 10¹³ ions/cm² at 300 K. The defect accumulation as a function of fluence was studied to determine changes in structural and optical properties. The variation in the fundamental Raman modes of the crystalline 6HSiC due to irradiation has been correlated with the disorder accumulation. The creation of defect states due to irradiation in the bandgap affects the blue-green photoluminescence emission in the irradiated samples. The UV-Visible absorption studies support the existence of defect states in the bandgap which is observed by the shift in the absorption edge towards the lower energy side with increasing fluence. Time Correlated Single Photon Counting photoluminescence decay results suggest that the existing defect states are radiative, exhibiting three lifetimes when irradiated with a fluence 5 × 10¹¹ ions/cm². The total number of lifetime components was reduced for a fluence 1 × 10¹³ ions/cm² as the defect states produced increase the non-radiative defect centres. These results suggest that the accumulation of defects due to irradiation at fluences 5 × 10¹¹ and 1 × 10¹³ ions/cm² are degenerate configurations which exhibit multiple lifetimes in photoluminescence studies. It is inferred that the optically active defect states influence the transition rate of charge carriers in this device material.     

Effect of ion beam irradiation on magnetic and structural properties of Pt/Cr/Co multilayers

This paper discusses the effect of ion beam irradiation on the magnetic and structural properties of Pt/Cr/Co multilayers. We observe Co-Cr-Pt ternary alloy phase formation in 1 MeV N⁺ ion irradiated [Pt (2.5 nm)/Cr (0.8 nm)/Co (3.0 nm)]_×6/Si multilayers for a fluence of 1 × 10¹⁶ ions cm⁻² and beyond. The observed phase formation is accompanied by an enhancement in the average grain size, surface roughness and coercivity. Monte Carlo simulation has been performed to study ion-induced defect evolution and atomic displacements to correlate the above observed effects.     

反应堆脉冲中子和γ射线辐照SiGe HBT器件的退火因子及典型直流参数测量分析

本工作测量了反应堆脉冲中子、γ辐照SiGe HBT典型直流电参数和退火因子.在反应堆1×1013 cm2的脉冲中子注量和257 Gy(Si)γ总剂量辐照后,SiGe HBT静态共射极直流增益减小了20%.辐照后基极电流、结漏电流增大,集电极电流、击穿电压减小.初步分析了SiGe HBT瞬态中子、γ辐射损伤机理.     

Effects of Nd:YAG laser irradiation on structural and magnetic properties of Li0.5Fe2.5O4

In the present paper we report our results on the effect of Nd:YAG laser irradiation on the structural and magnetic properties of Li_0.5Fe_2.5O₄ spinel ferrite prepared by solid-state reaction technique. X-ray diffraction analysis was carried out to confirm the formation of the single phase cubic spinel structure. The lattice constant calculated from X-ray diffraction data (XRD) goes on increasing with non irradiated phase to exceeding higher doses of irradiation. The distribution of the substituted ions over the different lattice sites is determined from XRD and infrared spectra. The damage structure and morphological investigations were carried out by using scanning electron microscopy and transmission electron microscopy techniques. It has been observed from our data on magnetic properties that laser irradiation severely affects the magnetization. From the magnetization measurements it has been observed that the saturation magnetization decreases with increase in the laser dose rate. The observed reduction in the saturation magnetization after irradiation is understood on the basis of the partial formation of paramagnetic centers and rearrangement of cations in the lattice.     

Investigations of structural, dielectric and optical properties on silicon ion irradiated glycine monophosphate single crystals

The 50 MeV silicon ion irradiation induced modifications on structural, optical and dielectric properties of solution grown glycine monophosphate (GMP) crystals were studied. The high-resolution X-ray diffraction study shows the unaltered value of integrated intensity on irradiation. The dielectric constant as a function of frequency and temperature was studied. UV-visible studies reveal the decrease in bandgap values on irradiation and presence of F-centers. The fluorescence spectrum shows the existence of some energy levels, which remains unaffected after irradiation. The scanning electron micrographs reveal the defects formed on irradiation.     

辐照红苕酒中醇、酯及酸的毛细管柱气相色谱测定

国内外关于酒分析的报道甚多,国内采用毛细管色谱剖析白兰地酒效果很好。但是有关辐照酒,特别是辐照红苕酒的分析资料尚不多见。本文就红苕酒经γ-射线辐照前后醇、酯及酸的测定结果报告如下。     

Thermoluminescence properties of nanocrystalline K2Ca2(SO4)3:Eu irradiated with gamma rays and proton beam

Thermoluminescence properties of nanocrystalline K₂Ca₂(SO₄)₃:Eu prepared by ball milling technique have been studied and the nanophosphor’s suitability as an effective gamma radiation and proton beam dosimeter material has been examined. It is found that the nanophosphor is suitable for dosimetry over a very wide range of doses ∼1 Gy to 1 kGy for gamma radiation. And for proton beam the same nanophosphor shows a more or less linear response for the dose range 0.1-100 Gy. A comparative study of this nanophosphor with its corresponding microcrystalline form (prepared by solid-state diffusion method) as well as the nanocrystalline form prepared by (the more conventional) co-precipitation technique has shown that the nanophosphor prepared by the ball milling technique is in almost all respects better than the other two forms reported earlier.     

电子束注入PMMA空间电荷分布的Monte-Carlo模拟与实验验证

精确控制和测量电子束注入样品后电荷量以及电荷的沉积分布,对于进行高压电力电缆材料的击穿以及航空器受到高能宇宙射线破坏的研究有着非常重要的意义。本工作结合空间电荷对固体电介质材料击穿影响的研究课题,利用Monte-Carlo方法模拟计算了电子束注入聚甲基丙烯酸甲脂(PMMA)样品中电荷的沉积分布,并通过激光感应压力波法(LIPP)对电子束注入后的PMMA进行测量;实验验证计算结果,吻合较好,为以后实验参数的设计提供了重要依据。     

CLAM钢、EUROFER97钢与钨在HT-7托卡马克中辐照后的表面分析

两种低活化马氏体钢(CLAM、EUROFER97)以及钨被放入HT-7托卡马克的刮削层中,以研究托卡马克装置中高温等离子体与低活化马氏体钢和钨表面的相互作用。通过SEM装置观察,发现某些样品的表面形貌发生了很大变化。低活化马氏体钢的表面起泡比较密集,钨的表面起泡比较稀少,且直径较大。在一些样品的表面,还观察到了等离子体灰尘以及明显的被等离子体冲击后的痕迹。另外,XPS分析发现样品表面的某些元素成分也发生了变化,而且处在托卡马克装置中不同位置处的样品,其表面硅的含量呈现出明显的规律性。     

Effect of swift heavy ion irradiation on structural, optical and electrical properties of Cd2SnO4 thin films

Transparent conducting cadmium stannate thin films were prepared by spray pyrolysis method on Corning substrate at a temperature of 525 °C. The prepared films are irradiated using 120 MeV swift Ag⁹⁺ ions for the fluence in the range 1 × 10¹² to 1 × 10¹³ ions cm⁻² and the structural, optical and electrical properties were studied. The intensity of the film decreases with increasing ion fluence and amorphization takes place at higher fluence (1 × 10¹³ ions cm⁻²). The transmittance of the films decreases with increasing ion fluence and also the band gap value decreases with increasing ion fluence. The resistivity of the film increased from 2.66 × 10⁻³ Ω cm (pristine) to 5.57 × 10⁻³ Ω cm for the film irradiated with 1 × 10¹³ ions cm⁻². The mobility of the film decreased from 31 to 12 cm²/V s for the film irradiated with the fluence of 1 × 10¹³ ions cm⁻².     

Sorption and Desorption Behavior of 60Co, 85Sr,and 137Cs in a Porous Tuff

Sorption experiments of ⁶⁰Co, ⁸⁵Sr and ¹³⁷Cs were carried out to study sorption characteristics onto a porous tuff. Sorption kinetics and rate controlling step were examined. The effects of particle size on sorption and distribution ratio were also investigated. Desorption experiments were carried out by using extracting reagents to distinguish sorption mechanisms such as reversible sorption in groundwater condition, ion exchange, association with ferro-manganese oxides or oxyhydroxides, and irreversible fixation. Strontium sorbed onto the tuff surface mainly by the ion exchange reaction which was fast and reversible. Cobalt and cesium do not sorb by simple step. The main sorptive binding of cobalt was the association with ferro-manganese oxides and the secondary one was the irreversible fixation. Diffusion into the lattice of rock minerals controlled the sorption rate of cobalt. The main sorption of cesium was the irreversible fixation, secondary one was the ion exchange.     

XRF法无标分析人造金刚石原料锭中Fe、Ni、Cr、Co组分及其分布

介绍了用X射线荧光光谱(XRF)法无标分析人造金刚石原料锭样品的制备和测量方法.用车加工制备出了满足XRF测量的分析试样,应用Spectraplus无标分析软件实现了对人造金刚石原料锭中Fe、Ni、Cr、Co组分及其分布的无标分析,该方法简便、快速.     

Migration Behavior of Radionuclides (60Co, 85Sr and 137Cs) in Aerated Sandy Soil Layer

Differences of the migration behavior and desorption process for radionuclides (⁶⁰Co, ⁸⁵Sr and ¹³⁷Cs) in aerated sandy soil layer were studied by sprinkle of distilled water into the contaminated soil with above nuclides in column. Influence of difference desorption process on radionuclide migration was examined by changing the volume of distilled water sprinkled like rain on the contaminated soil.

Quantity of sprinkled water affected the concentration distribution of each radionuclide in soil layer. Each nuclide migrated deeper in the layer according to the increase of water amount, and especially, migration behavior of ⁸⁵Sr was remarkably influenced by water amount. It is observed that as to ⁸⁵Sr maximum contamination part in soil layer moved to deeper layer with increase of water amount, and that, as to ⁶⁰Co and ¹³⁷Cs, it moved almost never. On the other hand, activity concentration of ⁶⁰Co or ¹³⁷Cs in effluent was rather high (10^?6 μCi/ml) compared with that of ⁸⁵Sr, which could not be detected therein.     

Spatial Distribution of Bremsstrahlung in Water and Water-Iron by 22-MeV Electron Bombardment Measured with Activation Detectors

The spatial distributions of bremsstrahlung in water (1 m thick) and water (60 cm thick)-iron (6.3 cm thick) bombarded by 22-MeV electrons were measured by using a new activation method which we developed. These informations are useful for studying shielding, residual activity and radiation damage of accelerator and target materials.

From the measured activities, the bremsstrahlung spectra in water were evaluated with the LYRA and the SAND-II unfolding codes. The evaluated spectra were in good agreement with the analytical calculation by the DIBRE code, except for the higher energy ends. The longitudinal and the lateral distributions of bremsstrahlung flux in water were obtained by integrating the evaluated spectra above 8 MeV. The agreement of the experimental and the calculated flux distributions was very good except for a large angle to beam direction. The total photon number crossing a plane normal to the beam axis attenuates exponentially along the axial depth. The iso-flux contour of bremsstrahlung flux was given by interpolating the flux distribution curves.

Only the saturated activities of gold detectors were obtained for water-iron in good experimental accuracy. The spatial distribution of gold saturated activities in water-iron clearly shows the attenuating effect due to strong absorption in iron.     

Equilibrium Distributions of Actinides and Fission Products in Pyrochemical Separation Systems, (II) LiCl-KCl/Cd System

Equilibrium distributions of actinides and fission products were determined in a LiCl-KCl/Cd system at 800–973 K. The redox potential of the system was controlled with the addition of reductant Li. Different distribution behaviors due to different group elements were observed. The group partitioning in this system was thus supported to be feasible. On reduction, however, the actinide and lanthanide elements were found to be less soluble in the Cd phase and to remain at the interface in the form of their solid intermetallics. A group partitioning process in which reductive extraction is combined with filtration was proposed on the basis of the present observations.