Effect of excitation type on dynamic system parameters of a reinforced concrete bridge

Wahab, M.M. Abdel,De Roeck, G. Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.7 No.4

Damage detection in civil engineering structures using the change in dynamic system parameters has gained a lot of scientific interest during the last decade. By repeating a dynamic test on a structure after a certain time of use, the change in modal parameters can be used to quantify and qualify damages. To be able to use the modal parameters confidentially for damage evaluation, the effect of other parameters such as excitation type, ambient conditions,... should be considered. In this paper, the influence of excitation type on the dynamic system parameters of a highway prestressed concrete bridge is investigated. The bridge, B13, lies between the villages Vilvoorde and Melsbroek and crosses the highway E19 between Brussels and Antwerpen in Belgium. A drop weight and ambient vibration are used to excite the bridge and the response at selected points is recorded. A finite element model is constructed to support and verify the dynamic measurements. It is found that the difference between the natural frequencies measured using impact weight and ambient vibration is in general less than 1%.

A 2-D four-noded finite element containing a singularity of order λ

Abdel Wahab, M.M.,de Roeck, G. Techno-Press 1995 Structural Engineering and Mechanics, An Int'l Jou Vol.3 No.4

A 2-D four-noded finite element which contains a ${\lambda}$ singularity is developed. The new element is compatible with quadratic standard isoparametric elements. The element is tested on two different examples. In the first example, an edge crack problem is analyzed using two different meshes and different integration orders. The second example is a crack perpendicular to the interface problem which is solved for different material properties and in turn different singularity order ${\lambda}$. The results of those examples illustrate the efficiency of the proposed element.

Fibrin Sealant and Lipoabdominoplasty in Obese Grade 1 and 2 Patients

Amr Abdel Wahab Mabrouk,Hesham Aly Helal,Soha Fathy Al Mekkawy,Nada Abdel Sattar Mahmoud,Ahmed Mohamed Abdel-Salam 대한성형외과학회 2013 Archives of Plastic Surgery Vol.40 No.5

Background Ever since lipoabdominoplasty was first developed to achieve better aesthetic outcomes and less morbidity, the rate of seroma formation, especially in obese patients, has disturbed plastic surgeons. The aim of this study was to evaluate the effect of fibrin sealant in the prevention of seroma formation after lipoabdominoplasty in obese patients. Methods Sixty patients with a body mass index (BMI) between 30 and 39.9 were assigned randomly to 1 of 2 groups (30 patients each). Group A underwent lipoabdominoplasty with fibrin glue, while group B underwent traditional lipoabdominoplasty; both had closed suction drainage applied to the abdomen. The patients’ demographics and postoperative complications were recorded. Seroma was detected using abdominal ultrasound examinations at two postoperative periods: between postoperative days 10 and 12 and, between postoperative days 18and 21. Results The age range was 31 to 55 years (38.5±9.5 years) in group A and 25 to 58 years (37.8±9.1 years) in group B, while the mean BMI was 31.4 to 39.9 kg/m2 (32.6 kg/m2) in group A and 32.7 to 37.4 kg/m2 (31.5 kg/m2) in group B. In group A, the patients had a complication rate of 10% in group A versus 43% in group B (P<0.05). The incidence of seroma formation was 3% in the fibrin glue group but 37% in the lipoabdominoplasty-alone group (P<0.05). Conclusions Lipoabdominoplasty with the use of autologous fibrin sealant is a very effective method that significantly reduces the rate of postoperative seroma.

Fibrin Sealant and Lipoabdominoplasty in Obese Grade 1 and 2 Patients

Mabrouk, Amr Abdel Wahab,Helal, Hesham Aly,Al Mekkawy, Soha Fathy,Mahmoud, Nada Abdel Sattar,Abdel-Salam, Ahmed Mohamed Korean Society of Plastic and Reconstructive Surge 2013 Archives of Plastic Surgery Vol.40 No.5

Background Ever since lipoabdominoplasty was first developed to achieve better aesthetic outcomes and less morbidity, the rate of seroma formation, especially in obese patients, has disturbed plastic surgeons. The aim of this study was to evaluate the effect of fibrin sealant in the prevention of seroma formation after lipoabdominoplasty in obese patients. Methods Sixty patients with a body mass index (BMI) between 30 and 39.9 were assigned randomly to 1 of 2 groups (30 patients each). Group A underwent lipoabdominoplasty with fibrin glue, while group B underwent traditional lipoabdominoplasty; both had closed suction drainage applied to the abdomen. The patients' demographics and postoperative complications were recorded. Seroma was detected using abdominal ultrasound examinations at two postoperative periods: between postoperative days 10 and 12 and, between postoperative days 18 and 21. Results The age range was 31 to 55 years ($38.5{\pm}9.5$ years) in group A and 25 to 58 years ($37.8{\pm}9.1$ years) in group B, while the mean BMI was 31.4 to 39.9 $kg/m^2$ (32.6 $kg/m^2$) in group A and 32.7 to 37.4 $kg/m^2$ (31.5 $kg/m^2$) in group B. In group A, the patients had a complication rate of 10% in group A versus 43% in group B (P<0.05). The incidence of seroma formation was 3% in the fibrin glue group but 37% in the lipoabdominoplasty-alone group (P<0.05). Conclusions Lipoabdominoplasty with the use of autologous fibrin sealant is a very effective method that significantly reduces the rate of postoperative seroma.

Screening thirty soybean genotypes under solid and intercropping plantings in Egypt

Abd El-Alim A. Metwally,Sayed A. Safina,Eman I. Abdel-Wahab,Sherif I. Abdel-Wahab,Tamer I. Abdel-Wahab 한국작물학회 2021 Journal of crop science and biotechnology Vol.24 No.2

Cropping systems are relatively more important for testing soybean genotypes under Egyptian conditions. A field experiment was carried out at the Agricultural Experiments and Research Station, Faculty of Agriculture, Cairo University, Giza, Egypt, during the 2016 and 2017 seasons to evaluate the productivity of thirty soybean genotypes collected from four countries in intercropping with corn. Intercropping two soybean ridges alternating with another two of corn (2:2) was used in a split plot distributed in randomized complete block design. Intercropping and solid systems were randomly assigned to the main plots, and the soybean genotypes were allocated in sub-plots. All over the genotypes, intercropping caused significant increases in maturity date, root length, and plant height; meanwhile, the reverse was true for each of total leaf chlorophyll content, numbers of branches and pods, as well as seed yield per plant. Soybean genotypes Giza 111, C1, Woodworth, C34, Hill, Hutcheson, and Holladay gave higher seed yield than the others. Allover cropping systems, soybean genotypes Giza 111, Woodworth, Hutcheson, and C1 had higher seed yield than the others under intercropping. A significant positive correlation was detected between pod number and seed yield under cropping systems. Early maturing genotypes under intercropping were correlated positively with a higher yield of plants, as well as relative values. Determinate soybean variety Woodworth was matured under intercropping and solid planting at the same time. Soybean genotypes Woodworth, C1, C34, Giza 35, Giza 82, and Giza 111 were tolerant than the others to intercropping. The six soybean genotypes off er useful genetic materials for soybean breeding programs to improve yield under intercropping.

Serum Talin-1 is a Potential Novel Biomarker for Diagnosis of Hepatocellular Carcinoma in Egyptian Patients

Youns, Mahmoud M.,Abdel Wahab, Abdel Hady A.,Hassan, Zeinab A.,Attia, Mohamed S. Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Background: Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide. The outcome of HCC depends mainly on its early diagnosis. To date, the performance of traditional biomarkers is unsatisfactory. Talins were firstly identified as cytoplasmic protein partners of integrins but Talin-1 appears to play a crucial role in cancer formation and progression. Our study was conducted to assess the diagnostic value of serum Talin-1 (TLN1) compared to the most feasible traditional biomarker alpha-fetoprotein (AFP) for the diagnosis of HCC. Methods: TLN1 was detected using enzyme linked immunosorbent assay (ELISA) in serum samples from 120 Egyptian subjects including 40 with HCC, 40 with liver cirrhosis (LC) and 40 healthy controls (HC). Results: ROC curve analysis was used to create a predictive model for TLN1 relative to AFP in HCC diagnosis. Serum levels of TLN1 in hepatocellular carcinoma patients were significantly higher compared to the other groups (p<0.0001). The diagnostic accuracy of TLN1 was higher than that of AFP regarding sensitivity, specificity, positive predictive value and negative predictive value in diagnosis of HCC. Conclusions: The present study showed for the first time that Talin-1 (TLN1) is a potential diagnostic marker for HCC, with a higher sensitivity and specificity compared to the traditional biomarker AFP.

Comparing U-Net convolutional network with mask R-CNN in Nuclei Segmentation

Zanaty, E.A.,Abdel-Aty, Mahmoud M.,ali, Khalid abdel-wahab International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.3

Deep Learning is used nowadays in Nuclei segmentation. While recent developments in theory and open-source software have made these tools easier to implement, expert knowledge is still required to choose the exemplary model architecture and training setup. We compare two popular segmentation frameworks, U-Net and Mask-RCNN, in the nuclei segmentation task and find that they have different strengths and failures. we compared both models aiming for the best nuclei segmentation performance. Experimental Results of Nuclei Medical Images Segmentation using U-NET algorithm Outperform Mask R-CNN Algorithm.

An isogeometric finite element approach for thermal bending and buckling analyses of laminated composite plates

Tran, Loc V.,Wahab, M. Abdel,Kim, Seung-Eock Elsevier 2017 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.179 No.-

<P><B>Abstract</B></P> <P>Temperature rise in a plate structure produces non-zero transverse normal strain. Thus, a six-variable quasi-3D model with one additional variable in transverse displacement of higher-order shear deformation theory (HSDT) is developed in this paper to take into account the effects of transverse shears and normal strain in a laminated composite plate. The governing equation is discretized by isogeometric analysis (IGA), which naturally fulfills the <I>C</I> <SUP>1</SUP>-continuity requirement of the plate model. Due to the presence of bending-extension coupling, two kinds of thermal plate issues are considered – thermal buckling and thermal bending phenomena. Several numerical examples are provided to show the accuracy of the present method compared to reference results. Furthermore, it has been confirmed that the transverse normal strain cannot be discarded, especially for thick plates under a temperature environment.</P>

Optical and structural characterization of ultrananocrystalline diamond/ hydrogenated amorphous carbon composite films deposited via coaxial arc plasma

Abdelrahman Zkria,Fouad Abdel-Wahab,Yuki Katamune,Tsuyoshi Yoshitake 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Ultrananocrystalline diamond/hydrogenated amorphous carbon composite films were deposited in the ambient of hydrogen by coaxial arc plasma deposition. The film compositions and chemical bonding structures were investigated by X-ray diffraction, X-ray photoemission and hydrogen forward scattering spectroscopies. The sp3 / (sp2 +sp3 ) ratio and hydrogen content in the film were estimated to be 64% and 35 at.%, respectively. The optical parameters and the optical dispersion profile were determined by using a variable angle spectroscopic ellipsometer at 55°, 65° and 75° angle of incidence in the photon energy range of 0.9–5 eV. Combinations of multiple Gaussian, and Tauc-Lorentz or Cody-Lorentz dispersion functions are used to reproduce the experimental data. Results of ellipsometry showed a refractive index of approximately 2.05 (at 2eV) and optical band gap of 1.63 eV. The imaginary part of dielectric function exhibited a peak at 3.8 eV, which has assigned to π-π* electron transitions. Furthermore, Electron spin resonance measurements implied the existence of dangling bonds, which might have a partial contribution to the optical absorption properties of the deposited films. A correlation between optical parameters and structural profile of the deposited films is discussed.

Transfer matrix formulations and single variable shear deformation theory for crack detection in beam-like structures

Baran Bozyigit,Yusuf Yesilce,Magd Abdel Wahab 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.2

This study aims to estimate crack location and crack length in damaged beam structures using transfer matrix formulations, which are based on analytical solutions of governing equations of motion. A single variable shear deformation theory (SVSDT) that considers parabolic shear stress distribution along beam cross-section is used, as well as, Timoshenko beam theory (TBT). The cracks are modelled using massless rotational springs that divide beams into segments. In the forward problem, natural frequencies of intact and cracked beam models are calculated for different crack length and location combinations. In the inverse approach, which is the main concern of this paper, the natural frequency values obtained from experimental studies, finite element simulations and analytical solutions are used for crack identification via plots of rotational spring flexibilities against crack location. The estimated crack length and crack location values are tabulated with actual data. Three different beam models that have free-free, fixed-free and simple-simple boundary conditions are considered in the numerical analyses.