Optical and Electrical Properties of a Metal-Semiconductor-Metal Material Based on Al-Doped ZnO Films for Use as UV Photodetectors

Sorour Jafari,Mohammad Hassan Yousefi,Fahimeh Zahedi 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.11

ZnO and ZnO:Al (aluminum-doped ZnO) thin films were grown on glass substrates at 480$^\circ$C by using a simple flexible spray pyrolysis method. The effects of Al doping on the structural, optical and electrical properties were investigated. X-ray diffraction (XRD) patterns showed successful growth of high-quality polycrystalline films on the substrates. The predominant orientation of the films was the (002) orientation. The microstructural parameters, such as the lattice parameters, the crystallite size ($D$), the microstrain ($\epsilon$), and the dislocation density ($d$) were calculated and found to depend upon the composition. Adding Al to the ZnO crystal structure decreased the crystallite size and increased the residual stress in the thin films. All films were highly transparent in the visible region with an average transmittance of 85 \%. Increasing the amount of the Al dopant increased the optical band gap from 3.26 to 3.34eV. A blue shift of the optical band gap from 400 nm to 380 nm with increasing Al doping percentage was observed in the PL spectrum. The spectrum in the UV range showed 1\% Al emission with a bandwidth of 100 nm (between 350 and 450 nm). Doping improved the electrical conductivity of the ZnO thin films, and the lowest resistivity was found for the thin film with 1\% Al doping. The I-V characteristics of the ZnO:Al thin films were measured in dark and under UV illumination. This study demonstrated that the 1\% Al-doped ZnO thin film exhibited physical properties, allowing better integration in optoelectronic devices.

Prevalence of obesity and overweight in Iranian children aged less than 5 years: a systematic review and meta-analysis

Kamyar Mansori,Sorour Khateri,Yousef Moradi,Zaher Khazaei,Hossein Mirzaei,Shiva Mansouri Hanis,Mehran Asadi Aliabadi,Mehdi Ranjbaran,Fatemeh Varse,Serveh Parang 대한소아청소년과학회 2019 Clinical and Experimental Pediatrics (CEP) Vol.62 No.6

Purpose: The present study aimed to determine the prevalence of childhood obesity and overweight in Iranian children under 5 years of age using a systematic review and meta-analysis. Methods: We searched MEDLINE (PubMed), Web of Science, Google Scholar, Scopus, CINHAL, and the Iranian databases, including Scientific Information Database (www.sid.ir), Iranian Research Institute for Information Science and Technology (Irandoc.ac.ir), Iranmedex (www.iranmedex.com), and Magiran (www.magiran.com), for all articles published between January 1989 and August 2017. Sources of heterogeneity were determined using subgroup analysis and meta-regression. Results: Six articles were ultimately included in the meta-analysis to estimate the pooled prevalence, based on which the prevalence of obesity and overweight were estimated to be 8% (95% confidence interval [CI], 6%–10%) and 9% (95% CI, 7%–11%), respectively. The results of the subgroup analysis showed that the prevalence of obesity in boys and girls was 9% (95% CI, 6%–13%) and 7% (95% CI, 4–10%), respectively, and the prevalence of overweight in boys and girls was 10% (95% CI, 5%–15%) and 9% (95% CI, 5%–13%), respectively. Conclusion: Despite high heterogeneity among the results of the articles included in the meta-analysis, the prevalence of obesity and overweight is higher in Iranian children under 5 years of age. Therefore, parents and the health system must pay more attention to the lifestyle, nutritional habits, and physical activity of these children.

Serum Beta-2 Microglobulin: a Possible Marker for Disease Progression in Egyptian Patients with Chronic HCV Related Liver Diseases

Ouda, SM,Khairy, AM,Sorour, Ashraf E,Mikhail, Mikhail Nasr Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: Egypt has the highest prevalence of HCV infection in the world (~14.7%). Around 10-15% of HCV-infected persons will advance to cirrhosis within the first 20 years. The incidence of HCC is expected to grow in the next two decades, largely due to HCV related cirrhosis, and detection of HCC at an early stage is critical for a favorable clinical outcome. No simple reliable non-invasive marker has been available till now. B2M, a non-glycosylated polypeptide composed of 99 amino acids, is one of the components of HLA class I molecules on the surfaces of all nucleated cells. It has been reported that the level of serum B2M is elevated in patients with chronic hepatitis C and HCV-related HCC when compared to HCV-negative patients or healthy donors. Determining the clinical utility of serum B2M as a marker for disease progression in Egyptian patients with HCV related chronic hepatitis, cirrhosis and hepatocellular carcinoma was the aim of the present study. Materials and Methods: In this analytical cross sectional study 92 participants were included in 4 equal groups: Group (1) non cirrhotic chronic HCV; Group (2) HCV related liver cirrhosis; Group (3) HCC on top of HCV,; and Group (4) healthy controls. History taking, clinical examination, routine labs and abdominal ultrasound were conducted for all patients, PCR and Metavir scores for group (1) patients, and triphasic CT abdomen and AFP for Group (3) patients. B2M levels were measured in serum with a fully-automated IMX system. Results: The mean serum B2M level of Group (1) was $4.25{\pm}1.48{\mu}g/ml$., Group (2) was $7.48{\pm}3.04$, Group (3) was $6.62{\pm}2.49$ and Group (4) was $1.62{\pm}0.63$. Serum B2M levels were significantly higher in diseased than control group (p<0.01) being significantly higher in cirrhosis ($7.48{\pm}3.04$) and HCC groups ($6.62{\pm}2.49$) than the HCV group ($4.25{\pm}1.48$) (p<0.01). There was a significant correlation between B2M Level and ALK, total and direct bilirubin and INR (p<0.05), and a significant inverse correlation between B2M level and albumin, total proteins, HB andWBCS values (p<0.05). There was no significant correlation between B2M level and viral load or Metavir score, largest tumour size or AFP (p>0.05). The best B2M cut-off for HCV diagnosis was 2.6 with a sensitivity of 100%, a specificity of 92%, a positive predictive value (PPV) of 97% and a negative predictive value (NPV) of 100%. The best B2M cut-off for HCC diagnosis was 4.55 which yielded sensitivity, specificity, positive predictive value, negative predictive values of 74%, 62%, 39.5, 87.8% respectively (p-value <0.01) while best cut-off for cirrhosis was 4.9, with sensitivity 74 % and specificity 74%.The sensitivity for HCC diagnosis increased upon B2M and AFP combined estimation to 91%, specificity to 79%, NPV to 95% and accuracy to 83%. Conclusions: Serum B2M level is elevated in HCV related chronic liver diseases and may be used as a marker for HCV disease progression towards cirrhosis and carcinoma.

Dynamic Parameter Adaptation for M-LWDF/M-LWWF Scheduling

Ju Yong Lee,Sorour, S.,Valaee, S.,Wonyoung Park IEEE 2012 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.11 No.3

<P>M-LWWF/M-LWDF scheduling schemes have attracted much interest due to their ability to both stabilize queues whenever possible and control delay through parameter selection. However, a good implementation of these schedulers would require a mechanism to minimize the required fraction of the bandwidth while satisfying its stability and delay requirements. To the best of our knowledge, previous works on these scheduling policies did not address the problem of minimizing the bandwidth utilization while satisfying delay constraints. In this paper, we explore the solution of this problem using a joint bandwidth and weight adaptation approach. We characterize the problem solution space for M-LWWF and M-LWDF scheduling, assuming time-varying traffic. We also show that, starting from any point in the solution space, simple dynamic bandwidth and weight updates can surely lead to the convergence to the optimal operation point in this space. Based on these characteristics, we propose a dynamic parameter adaptation algorithm that is able to track the time-varying optimal operation points for dynamic traffic and channel conditions. Simulation results show the efficiency of our proposed algorithm in tracking the optimal operation points in dynamic traffic and channel settings.</P>

Prevalence of obesity and overweight in Iranian children aged less than 5 years: a systematic review and meta-analysis

Mansori, Kamyar,Khateri, Sorour,Moradi, Yousef,Khazaei, Zaher,Mirzaei, Hossein,Hanis, Shiva Mansouri,Aliabadi, Mehran Asadi,Ranjbaran, Mehdi,Varse, Fatemeh,Parang, Serveh The Korean Pediatric Society 2019 Clinical and Experimental Pediatrics (CEP) Vol.62 No.6

Purpose: The present study aimed to determine the prevalence of childhood obesity and overweight in Iranian children under 5 years of age using a systematic review and meta-analysis. Methods: We searched MEDLINE (PubMed), Web of Science, Google Scholar, Scopus, CINHAL, and the Iranian databases, including Scientific Information Database (www.sid.ir), Iranian Research Institute for Information Science and Technology (Irandoc.ac.ir), Iranmedex (www.iranmedex.com), and Magiran (www.magiran.com), for all articles published between January 1989 and August 2017. Sources of heterogeneity were determined using subgroup analysis and meta-regression. Results: Six articles were ultimately included in the meta-analysis to estimate the pooled prevalence, based on which the prevalence of obesity and overweight were estimated to be 8% (95% confidence interval [CI], 6%-10%) and 9% (95% CI, 7%-11%), respectively. The results of the subgroup analysis showed that the prevalence of obesity in boys and girls was 9% (95% CI, 6%-13%) and 7% (95% CI, 4-10%), respectively, and the prevalence of overweight in boys and girls was 10% (95% CI, 5%-15%) and 9% (95% CI, 5%-13%), respectively. Conclusion: Despite high heterogeneity among the results of the articles included in the meta-analysis, the prevalence of obesity and overweight is higher in Iranian children under 5 years of age. Therefore, parents and the health system must pay more attention to the lifestyle, nutritional habits, and physical activity of these children.

Effect of process control mode on weld quality of friction stir welded plates

Mostafa Shazly,Sherif Sorour,Ahmed R. Alian 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

Friction stir welding (FSW) is a solid state welding process which requires no filler material where the heat input is generated by frictionalenergy between the tool and workpiece. The objective of the present work is to conduct a fully coupled thermomechanical finiteelement analysis based on Arbitrary Lagrangian Eulerian (ALE) formulation for both “Force-Controlled” and “Displacement-Controlled”FSW process to provide more detailed insight of their effect on the resulting joint quality. The developed finite element models use Johnson-Cook material model and temperature dependent physical properties for the welded plates. Efforts on proper modeling of the underlyingprocess physics are done focusing on the heat generation of the tool/workpiece interface to overcome the shortcomings of previousinvestigations. Finite elements results show that “Force-Controlled” FSW process provides better joint quality especially at higher travelingspeed of the tool which comes to an agreement with published experimental results.

ON THE CURVATURE FUNCTIONS OF TUBE-LIKE SURFACES IN THE GALILEAN SPACE

Abdel-Aziz, Hossam Eldeen S.,Sorour, Adel H. Korean Mathematical Society 2021 대한수학회논문집 Vol.36 No.3

In the Galilean space G₃, we study a special kind of tube surfaces, called tube-like surfaces. They are defined by sweeping a space curve along another central space curve. In this setting, we investigate some equations in terms of Gaussian and mean curvatures, showing some relevant theorems. Our theoretical results are illustrated with some plotted examples.

ON SOME GEOMETRIC PROPERTIES OF QUADRIC SURFACES IN EUCLIDEAN SPACE

Ali, Ahmad T.,Aziz, H.S. Abdel,Sorour, Adel H. The Honam Mathematical Society 2016 호남수학학술지 Vol.38 No.3

This paper is concerned with the classifications of quadric surfaces of first and second kinds in Euclidean 3-space satisfying the Jacobi condition with respect to their curvatures, the Gaussian curvature K, the mean curvature H, second mean curvature $H_{II}$ and second Gaussian curvature $K_{II}$. Also, we study the zero and non-zero constant curvatures of these surfaces. Furthermore, we investigated the (A, B)-Weingarten, (A, B)-linear Weingarten as well as some special ($C^2$, K) and $(C^2,\;K{\sqrt{K}})$-nonlinear Weingarten quadric surfaces in $E^3$, where $A{\neq}B$, A, $B{\in}{K,H,H_{II},K_{II}}$ and $C{\in}{H,H_{II},K_{II}}$. Finally, some important new lemmas are presented.

Current progress in application of polymeric nanofibers to tissue engineering

신흥수,신영민,Se-jeong Kim,Sorour Nemati 나노기술연구협의회 2019 Nano Convergence Vol.6 No.36

Tissue engineering uses a combination of cell biology, chemistry, and biomaterials to fabricate three dimensional (3D) tissues that mimic the architecture of extracellular matrix (ECM) comprising diverse interwoven nanofibrous structure. Among several methods for producing nanofibrous scaffolds, electrospinning has gained intense interest because it can make nanofibers with a porous structure and high specific surface area. The processing and solution parameters of electrospinning can considerably affect the assembly and structural morphology of the fabricated nanofibers. Electrospun nanofibers can be made from natural or synthetic polymers and blending them is a straightforward way to tune the functionality of the nanofibers. Furthermore, the electrospun nanofibers can be functionalized with various surface modification strategies. In this review, we highlight the latest achievements in fabricating electrospun nanofibers and describe various ways to modify the surface and structure of scaffolds to promote their functionality. We also summarize the application of advanced polymeric nanofibrous scaffolds in the regeneration of human bone, cartilage, vascular tissues, and tendons/ligaments.

ON SOME GEOMETRIC PROPERTIES OF QUADRIC SURFACES IN EUCLIDEAN SPACE

( Ahmad T. Ali ),( H. S. Abdel Aziz ),( Adel H. Sorour ) 호남수학회 2016 호남수학학술지 Vol.38 No.3

This paper is concerned with the classifications of quadric surfaces of first and second kinds in Euclidean 3-space satisfying the Jacobi condition with respect to their curvatures, the Gaussian curvature K, the mean curvature H, second mean curvature H< sub >II< /sub > and second Gaussian curvature K< sub >II< /sub >. Also, we study the zero and non-zero constant curvatures of these surfaces. Furthermore, we investigated the (A, B)-Weingarten, (A, B)-linear Weingarten as well as some special (C2, K) and (C2, K □)-nonlinear Weingarten quadric surfaces in E< sup >3< /sup >, where A ≠ B, A, B ∈ {K, H, H< sub >II< /sub >, K< sub >II< /sub >} and C ∈ {H, H< sub >II< /sub >, K< sub >II< /sub >}. Finally, some important new lemmas are presented.