MEASUREMENT THE EFFECT OF γ-IRRADIATION DOSES ON AlCu8.5 BY POSITRON ANNIHILATION DOPPLER-BROADENING SPECTROSCOPY

2007 ◽  
Vol 21 (22) ◽  
pp. 3901-3907
Author(s):  
M. A. ABDEL-RAHMAN ◽  
M. ABDEL-RAHMAN ◽  
M. ABO-ELSOUD ◽  
M. F. EISSA ◽  
YAHIA A. LOTFY ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Irradiation Dose ◽  
Room Temperature ◽  
Doppler Broadening ◽  
Γ Irradiation ◽  
Second Stage ◽  
S Parameter ◽  
Controlling Mechanism ◽  
Γ Ray ◽  
Two Stages

The effect of irradiation dose (kGy) on a set of AlCu 8.5 samples has been studied. The samples were irradiated to doses of 10, 30, 50, 70, 100, 300, 500, 700 and 1000 kGy of 60 Co γ-source at room temperature. The effect of γ-ray irradiation on the values of the S- and W-parameters reveals two stages. In the first stage, the S-parameter increases, while the W-parameter decreases up to 70 kGy. In the second stage, the S- and W-parameters decrease and increase respectively in the dose region from 100 to 1000 kGy. The dominant controlling mechanism of the S- and W-parameters was observed.

The Influence of Heat and Two Stages Precipitation in the Process of Natural Polymer Purification from the Byproduct of Bioethanol Process Base on Empty Palm Fruit Bunch

2015 ◽  
Vol 1123 ◽  
pp. 177-181
Author(s):  
Achmad Hanafi ◽  
Harry Budiman ◽  
Fauzan Aulia
Keyword(s):  
Sulfuric Acid ◽  
Sodium Hydroxide ◽  
Room Temperature ◽  
Black Liquor ◽  
Ash Content ◽  
Natural Polymer ◽  
Palm Fruit ◽  
Second Stage ◽  
Direct Precipitation ◽  
Two Stages

The biopolymer material, lignin, was recovered from the black liquor by acidification of the black liquor using sulfuric acid. Several purification techniques were carried out to produce the high purity of lignin such as gradual precipitation of lignin from black liquor (first stage: precipitation at pH 7, second stage: precipitation at pH 2) and the diluting of crude lignin by sodium hydroxide then followed by re-precipitation at different temperature. Subsequently, the impurities of lignin product resulted from each purification techniques was determined as ash content that analyzed using temperature program furnace; and the content of lignin was investigated using spectrophotometer UV-Vis. The result showed that the content of lignin of material produced from gradual precipitation was approximately 77.6%. It was higher than the content of lignin about 3.4% of material produced from direct precipitation to pH 2. In addition, the elevating of temperature from 40 to 60°C was no considerably affect to the content of lignin in precipitate produced from re-precipitation of crude lignin solution in sodium hydroxide. Nonetheless, the content of lignin of precipitate improved 15% when the temperature of re-precipitation of crude lignin solution in sodium hydroxide was raised from room temperature to 40-60°C.

The Evolution Behavior of Defects in the Nanofilms of W/Cu and W Probed by Doppler Broadening Positron Annihilation Spectroscopy

2017 ◽  
Vol 373 ◽  
pp. 104-107
Author(s):  
Ling Wang ◽  
Ai Hong Deng ◽  
Kang Wang ◽  
Yong Wang ◽  
Xiao Bo Lu ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Positron Annihilation ◽  
Room Temperature ◽  
Storage Time ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Radio Frequency Magnetron Sputtering ◽  
Helium Ions ◽  
Near Surface ◽  
Evolution Behavior

W/Cu multilayer nanofilms and pure W nanofilms were prepared in pure Ar and He/Ar mixing atmosphere by radio frequency magnetron sputtering method. The defect evolution of the samples was characterized by Doppler broadening positron annihilation spectroscopy (DB-PAS).The results show that plenty of defects can be produced by introducing helium (He) into W/Cu multilayer nanofilms. With the natural storage time increasing, the helium located in the near surface of W/Cu multilayer nanofilm would be released gradually and induce the coalescence of the helium related defects due to the diffusion of the helium and defects. In addition, the pure W nanofilms were irradiated by 30 keV helium ions and 40 keV hydrogen (H) ions in sequence at room temperature. From the DB-PAS analysis, it can be shown that a large number of vacancy-type defects are produced due to the He and/or H irradiation. H ions would be trapped by He related defects and produced He-H-V complexes.

Positron Lifetimes and Crystallinity of γ-Irradiated Polypropylenes

2012 ◽  
Vol 733 ◽  
pp. 163-166
Author(s):  
Zhe Chen ◽  
Wei Huang ◽  
Peng Fei Fang ◽  
Wen Yu ◽  
Shao Jie Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Irradiation Dose ◽  
Gamma Ray ◽  
Positron Lifetime ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Γ Ray ◽  
Positron Lifetimes ◽  
Dsc Method ◽  
Low Irradiation

The microstructure of the polypropylenes (PP) irradiated by gamma ray was studied by positron lifetime technique and differential scanning calorimetry (DSC). Lifetime measurement shows o-Ps intensity decreases with increasing γ irradiation dose. The crystallinity of irradiated samples was detected by DSC method. The correlation between o-Ps intensity and crystallinity indicates γ-ray can induce higher crystallinity in the polypropylene at low irradiation dose.

Effect of Buffer on the Optical Properties of Irradiated Hydroxyethyl Methacrylate Copolymer

2002 ◽  
Vol 17 (5) ◽  
pp. 1199-1207
Author(s):  
K. F. Chou ◽  
C. C. Han ◽  
Sanboh Lee
Keyword(s):  
Optical Properties ◽  
Irradiation Dose ◽  
Ph Value ◽  
Bathochromic Shift ◽  
Cutoff Wavelength ◽  
Hydroxyethyl Methacrylate ◽  
Γ Irradiation ◽  
Incident Wavelength ◽  
Γ Ray ◽  
Methacrylate Copolymer

The effect of buffer and γ irradiation on the optical properties of hydroxyethyl methacrylate (HEMA) copolymer was investigated. The transmission of HEMA copolymer decreased with the increase of irradiation dose and/or pH value of the buffer. The cutoff wavelength of HEMA copolymer exhibits a bathochromic shift as the γ-ray dose and/or pH value of buffer increases. The influence of atmosphere during γ-ray irradiation on the optical properties of HEMA copolymer was investigated. The change of optical properties of HEMA copolymer irradiated in air was more pronounced than that irradiated in vacuum. Light was scattered by holes in the polymer. The relationship between scattering intensity (Is) and incident wavelength (λ) can be described by the formula Is ∝ λ−n. The span of holes increases with the irradiation dose regardless of radiation atmosphere and pH value in the range of 4.1–6.5. A boundary between the inner and outer layers of HEMA copolymer irradiated in air was observed, separating two differential morphologies of holes.

Effect of Irradiation Doses on AlCu6.5 Alloy Using Positron Annihilation Doppler Broadening Technique

2008 ◽  
Vol 278 ◽  
pp. 15-24
Author(s):  
M. Abdel-Rahman ◽  
Yahia A. Lotfy ◽  
M.A. Abdel-Rahman ◽  
Emad A. Badawi
Keyword(s):  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Dose Effect ◽  
Doppler Broadening ◽  
Γ Irradiation ◽  
Cu Alloy ◽  
Versatile Tool ◽  
Parameter Values ◽  
Line Shape Parameter

Positron Annihilation Spectroscopy (PAS) is a powerful and versatile tool for the study of the microscopic structure of materials. Doppler Broadening Positron Annihilation Technique (DBPAT) is the fastest technique used among positron annihilation techniques. The dose effect in Al-6.5at. % Cu alloy was investigated by means of DBPAT. An abrupt change in both the S and W line-shape parameter values occurred at 70 kGy of irradiation. The S- and W-Parameters of the trapped positrons at 70 kGy of γ−irradiation dose are about 48 % and 14 % respectively. The S- versus W-parameter reveals a linear relationship indicating the presence of only one type of defect. The S- and W-parameters have been used in the determination of the positron trapping rate and the grain size of the AlCu6.5 alloy.

Temperature Dependence of Radiation Damage in ODS Steel Studied by Triple Beam Irradiation and Positron Annihilation Techniques

2017 ◽  
Vol 373 ◽  
pp. 91-95 ◽  
Author(s):  
Da Qing Yuan ◽  
Qiao Li Zhang ◽  
Ping Fan ◽  
Xian Ping Wang ◽  
Bin Long ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Positron Annihilation ◽  
Ion Beam ◽  
Positron Beam ◽  
Doppler Broadening ◽  
Beam Irradiation ◽  
Single Beam ◽  
Positron Annihilation Lifetime ◽  
Ods Steel ◽  
S Parameter

The oxide dispersed strengthened (ODS) ferritic-martensitic steel was irradiated by 100MeV iron ion whose energy was degraded by using a Ta foil of 4 μm thick, 100 keV Hydrogen and 200 keV Helium at 480, 515, 550 and 580 °C. The irradiation fluences were 1×1016, 1.1×1015 and 6.8×1013/cm2, respectively for Fe, H and He. The techniques of positron annihilation lifetime and Doppler broadening of slow positron beam were utilized to examine the produced radiation damage. At 550 °C the maximal positron annihilation lifetime and S parameter of Doppler broadening were observed, implyin g tha t 550 °C is the pea k temperature of swelling. The S parameter and annihilation lifetime of the sample irradiated at 515 °C by the single Fe ion beam were smaller compared to the triple beam irradiation at the same temperature, implying that the triple beam irradiation caused more severe damage than the single beam irradiation.

Oxidation Kinetics of the Sintered Iron Parts Steam Treated in an Industrial Continuous Furnace

2010 ◽  
Vol 660-661 ◽  
pp. 243-248
Author(s):  
Eduardo Nunes ◽  
Ivan Gilberto Sandoval Falleiros
Keyword(s):  
Oxidation Kinetics ◽  
Continuous Furnace ◽  
Steam Treatment ◽  
Sintered Iron ◽  
Second Stage ◽  
Parabolic Law ◽  
Controlling Mechanism ◽  
Iron Diffusion ◽  
Two Stages ◽  
Kinetics Of

It has been studied a steam treatment process in an industrial continuous furnace for sintered iron parts in a temperature range varying from 490 to 570 °C and sample´s sintered densities of 6,52 and 6,77 g / cm3 . The tests have showed oxidation kinetics with two stages, each of them obeying a parabolic law. The first stage was faster than the second. The oxidation time when the oxidation kinetics of the first stage has changed for the second stage showed off very sensitive to the process temperature and sintered densities of the parts which are in agreement with the process rate controlling mechanism that was found to be the iron diffusion through the oxide layer.

scholarly journals Temporary Shelter Simulation Towards Effectiveness Value of OTTV and Thermal Comfort

2019 ◽  
Vol 36 (3) ◽  
Author(s):  
Dyah Puspa Ayu ◽  
Budi Prayitno ◽  
Agus Hariyadi
Keyword(s):  
Thermal Comfort ◽  
Natural Disasters ◽  
Room Temperature ◽  
Human Life ◽  
Air Humidity ◽  
Value Differences ◽  
Second Stage ◽  
Thermal Transfer ◽  
A Value ◽  
Two Stages

Indonesia is prone to a variety of natural disasters, one of which is earthquakes. Earthquakes are detrimental to human life, causing among other things a loss of shelter. As such, victims of earthquakes need basic assistance in the form of shelter, which the Indonesian government provides in the transition phase of emergency responses. Several innovations in the provision of temporary shelter have arisen in terms of packaging and fast unloading. This research aimed to examine the effective value of OTTV energy (overall thermal transfer value), differences in room temperature, and thermal comfort in existing temporary shelters. OTTV values and thermal comfort are adapted to Indonesia's humid tropical climate, which has a temperature ranging 24–30°C and air humidity of 75%. Temporary shelters were simulated with Rhinoceros and Grasshopper softwares. The simulation was carried out in two stages, with the first stage simulating the temporary shelter materials and the second stage simulating according to a predetermined standard. The results concluded that the effective value of OTTV with the use of Styrofoam-based shelter gives a value of 27.63 W/m2 with a decrease of up to 4.70 W/m2 and the temperature drops to 2–3°C.

Positron Annihilation in Ion-Implanted ZnO

2010 ◽  
Vol 295-296 ◽  
pp. 1-10
Author(s):  
Aman Deep Acharya ◽  
Girjesh Singh ◽  
S.B. Shrivastava
Keyword(s):  
Positron Annihilation ◽  
Atomic Number ◽  
Zno Films ◽  
Doppler Broadening ◽  
Vacancy Clusters ◽  
S Parameter ◽  
Trapping Model ◽  
Ion Implanted

The Diffusion Trapping Model has been used to obtain the positron annihilation Doppler broadening lineshape parameter in ZnO and O+, B+, N+, Al+ implanted ZnO films. The concentration of vacancy clusters is found to be related to the atomic number and the fluence of the implanted ion. The S-parameter is found to be largest in the case of implantation of Al+ ions and is minimum for the implantation of B+ ions. Thus, the vacancy clusters are found to be largest in the case of Al+ implantation. The calculated results have been compared with the experimental value.

INFLUENCE OF Mg CONTENT ON TRAPPING EFFICIENCY IN Al–Mg SYSTEM BY POSITRON ANNIHILATION SPECTROSCOPY

2006 ◽  
Vol 13 (04) ◽  
pp. 485-488
Author(s):  
EMAD BADAWI ◽  
M. A. ABDEL-RAHMAN ◽  
M. O. ABDELHAMED
Keyword(s):  
Positron Annihilation ◽  
Cross Section ◽  
Positron Annihilation Spectroscopy ◽  
Trapping Efficiency ◽  
Doppler Broadening ◽  
Deformation Degree ◽  
S Parameter ◽  
Mean Lifetime ◽  
The Mean ◽  
Mg Content

PLT and Doppler broadening S-parameter were used for Al – Mg alloy, namely 5005, 5051, 5052 and 5083. The trapping efficiency was estimated for the pervious alloys as 2.42 × 109, 2.29 × 109, 2.24 × 109 and 2.27 × 109 s -1 cm 3, respectively and the trapping cross-section was estimated to be as 2.66 × 10-16, 2.14 × 10-16, 2.10 × 10-16 and 3.51 × 10-16 cm 2, respectively. It is clear that the mean lifetime and S-parameter have the same behavior as a function of deformation degree and saturated at the same value of thickness reduction.

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