The effect of geometrical parameters on the radon emanation coefficient and different radon parameters

El-Araby Entesar H.,Azazi A. 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11

Radon is a radioactive gas produced from the uranium-238 series. Radon gas affects public health and is the second cause of lung cancer. The study samples were collected from one area of the city of Jazan, southwest of the Kingdom of Saudi Arabia. The influence of engineering and physical parameters on the emanation coefficient of gas and other gas parameters was studied. Parameters for radon were measured using a CR-39 Solid-State Nuclear Track Detector (SSNTD) through a sealed emission container. The results showed that the emanation coefficient was affected directly by the change in the grain size of the soil. All parameters of measured radon gas have the same behavior as the emanation coefficient. The relationship between particle size and emanation coefficient showed a good correlation. The values of the emanation coefficient were inversely affected by the mass of the sample, and the rest of the parameters showed an inverse behavior. The results showed that increasing the volume of the container increases the accumulation of radon sons on the wall of the container, which increases the emission factor. The rest of the parameters of radon gas showed an inverse behavior with increasing container size. The results concluded that changing the engineering and physical parameters has a significant impact on both the emanation coefficient and all radon parameters. The emanation coefficient affects the values of the radiation dose of an alpha particle.

Creep and stress relaxation of a FeMnSi-based shape memory alloy at low temperatures

Leinenbach, C.,Lee, W.J.,Lis, A.,Arabi-Hashemi, A.,Cayron, C.,Weber, B. Elsevier Sequoia 2016 Materials science & engineering. properties, micro Vol.677 No.-

<P>The creep and stress relaxation behavior of a Fe-17Mn-5Si-10Cr-4Ni-1(V,C) (wt%) shape memory alloy at low homologous temperatures (-45 degrees C < T < 50 degrees C) was systematically studied in stress and strain controlled tensile tests. At constant stresses at -45 degrees C, the alloy exhibits pronounced creep up to 0.6% at 600 MPa after only 30 min holding time. If the strain is kept constant, a pronounced stress relaxation of up to 10% of the initial stress was observed. The final creep strains, the creep rates at a constant stress as well as the stress relaxation at a constant strain increase with decreasing temperature. In addition, the change of the recovery stress as a function of time in a restrained sample after 4% elongation and heating to different constant temperatures was monitored. It was observed that the increase of the final recovery stress is more pronounced when the holding temperature is increased. This behavior was explained with the time and temperature dependent formation of stress induced epsilon-martensite from the parent gamma-austenite phase during mechanical loading according to the model of Kajiwara et al. as well as with the increased number of stacking faults at lower temperatures, which serve as nucleation sites for the epsilon-martensite formation. (C) 2016 Elsevier B.V. All rights reserved.</P>

A novel approach to the synthesis of a wide range of ink jet printer pigment from yellow to magenta for tiles via gold nanoparticles

Sh. Saket,S. Rasouli,A. M. Arabi,M.A. Faghihi Sani 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.3

In this study, synthesis of Au and Au/Ag nano-pigments has been investigated. The results showed that pH controlling agents(PCAs) (NH4OH or NaOH) play an important role on the physical properties of Au/Ag nano-pigments and inks. X-raydiffraction (XRD) patterns indicated that pure metallic phase is formed by NH4OH PCAs. Morphological studies revealed theformation of nanometric spherical particles. The smallest size is belonged to Au particles prepared by NH4OH PCA. Becauseof the comparable hue and saturation of synthesized metallic pigments to the commercial inks, the obtained samples have beenintroduced as a suitable candidate for ceramic ink jet printing for tiles.

Optimal Design Parameters of Exhaust Valve Spring in IC Engines UsingMetaheuristic Algorithms

A. Arabi,H. osman 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

The exhaust valve is responsible for the engine"s smooth operation. Exhaust gases are directed from the combustion chamber to the exhaust manifold via the exhaust valve. Valve springs are subjected to tensile strains as a result of gas pressure fluctuations, fluctuating loads, and elasticity loosening as the IC engine runs. Excessive valve noise and internal engine damage can be caused by weak or cracked exhaust valve springs in an IC engine. Recent Metaheuristic Algorithms, such as Sin-Cos, PSO, GPSO, Cukoo, and ABC, are utilized in this study to find the best design parameters for the exhaust valve spring while keeping the spring"s deflection, shear stresses, and fatigue in mind. The PSO and Sin-Cos algorithms outperform the others in terms of speed of convergence, while the GPSO achieves a helical spring weight of 2.1N.

Molecular Characterization of Some Antilisterial Bacteriocin Genes from Enterococcus faecium and Pediococcus pentosaceus

El-Arabi, Nagwa I.,Salim, Rasha G.,Abosereh, Nivien A.,Abdelhadi, Abdelhadi A. The Korean Society for Microbiology and Biotechnol 2018 한국미생물·생명공학회지 Vol.46 No.3

Food bio preservation is of major interest in the food industry. Many types of antimicrobial compounds can be produced by lactic acid bacteria (LAB), including bacteriocins. Bacteriocins increase the shelf-life of food by decreasing some food-borne diseases. In this study, a multi-coding sequence of bacteriocin genes was used for primer design to produce bacteriocin genes in Enterococcus faecium AH2 strain and Pediococcus pentosaceus AH1. Multi-coding sequences were aligned to detect conserved sequences in the bacteriocin gene. Eight genes encoding proteins involved in bacteriocin production were isolated and sequenced, including six from E. faecium AH2 (entA, entI, entF, entR, orfA2, orfA3) and two from P. pentoceseus AH1 (papA, pedB), and all gene sequences were deposited in the Gen Bank database under accession numbers LC064146-LC064151, LC101300, and LC101789, respectively. P. pentosaceus AH1 and E. faecium AH2 strains displayed bacteriocin activities of $2610AU\;mL^{-1}$ and $690AU\;mL^{-1}$ and inhibition zones of 26 mm and 19 mm, respectively. Overexpression of entA in E. faecium AH2 increased the bacteriocin and antimicrobial activities.

Molecular Characterization of Some Antilisterial Bacteriocin Genes from Enterococcus faecium and Pediococcus pentosaceus

( Nagwa I. El-arabi ),( Rasha G. Salim ),( Nivien A. Abosereh ),( Abdelhadi A. Abdelhadi ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 한국미생물·생명공학회지 Vol.46 No.3

Food bio preservation is of major interest in the food industry. Many types of antimicrobial compounds can be produced by lactic acid bacteria (LAB), including bacteriocins. Bacteriocins increase the shelf-life of food by decreasing some food-borne diseases. In this study, a multi-coding sequence of bacteriocin genes was used for primer design to produce bacteriocin genes in Enterococcus faecium AH2 strain and Pediococcus pentosaceus AH1. Multi-coding sequences were aligned to detect conserved sequences in the bacteriocin gene. Eight genes encoding proteins involved in bacteriocin production were isolated and sequenced, including six from E. faecium AH2 (entA, entI, entF, entR, orfA2, orfA3) and two from P. pentoceseus AH1 (papA, pedB), and all gene sequences were deposited in the Gen Bank database under accession numbers LC064146-LC064151, LC101300, and LC101789, respectively. P. pentosaceus AH1 and E. faecium AH2 strains displayed bacteriocin activities of 2610 AU mL^-1and 690 AU mL^-1and inhibition zones of 26 mm and 19 mm, respectively. Overexpression of entA in E. faecium AH2 increased the bacteriocin and antimicrobial activities.

The comparison of radial and axial flow porous burners from viewpoint of output radiative heat transfer and emissions

Tabari, N. Ghiasi,Astaraki, M.R.,Arabi, A.H. Techno-Press 2012 Coupled systems mechanics Vol.1 No.3

In this paper, two types of porous burners with radial and axial flow have been modeled numerically and compared. For this purpose, governing equations were solved one-dimensionally for methane-air premix gas. The mechanism used in simulating combustion phenomenon was 15 stage reduced mechanism based on GRI3.0. In order to compare the two burners, the inlet flow rate and fuel-air ratio have been assumed equal for the two burners. The results of the study indicated that reduction in speed and increase in cross-section area in the direction of flow have a considerable influence on the behavior of radial burner in comparison to axial burner. Regarding temperature distribution inside the burner, it was observed that the two above mentioned factors can be influential in temperature of flame propagation region. Also, regarding distribution of CO and NO emission, the results indicate that the porous radial burner has lower emissions in comparison to the axial once. The output radiative heat transfer efficiency of the two burners was also compared and in this case also even the radial porous burner was found to be preferable.