Measurement of normalized spectral responsivity of digital imaging devices by using a LED-based tunable uniform source

Mahmoud, Khaled,Park, Seongchong,Park, Seung-Nam,Lee, Dong-Hoon The Optical Society 2013 Applied optics Vol.52 No.6

<P>We present an instrumentation solution for measurement of normalized spectral responsivity of digital imaging sensors and cameras. The instrument consists of multiple light-emitting diodes (LEDs), a single-grating monochromator, and a small-size integrating sphere. Wavelength tuning is achieved by a proper selection of LED in accordance with the monochromator setting in a range from 380 to 900 nm. High spectral purity with a bandwidth of 5 nm is realized without using double gratings and order-sorting filters. Experimental characteristics and calibration of the instrument are described with the related error and uncertainty sources. The performance is demonstrated by measuring a monochrome charge-coupled device and a trichromatic complementary metal-oxide-semiconductor device. The measurement uncertainty is evaluated to be less than 1% (k=2) except several wavelengths with low LED power.</P>

An imaging spectrophotometer for measuring the two-dimensional distribution of spectral reflectance

Mahmoud, Khaled,Park, Seongchong,Park, Seung-Nam,Lee, Dong-Hoon Springer-Verlag 2014 METROLOGIA -BERLIN- Vol.51 No.6

Towards the production of monodisperse gelatin nanoparticles by modified one step desolvation technique

Khaled S. Shamarekh,Heba A. Gad,Mahmoud E. Soliman,Omaima A. Sammour 한국약제학회 2020 Journal of Pharmaceutical Investigation Vol.50 No.2

Purpose The aim of the present study was to prepare gelatin nanoparticles (GNPs) using modified one step desolvation method to obtain small, uniformly sized, and spherical GNPs. Methods The modifications involved the preparation of high molecular weight gelatin (HMWG) by fractionation of gelatin. HMWG was freeze-dried to be used in a specified concentration for preparation of GNPs with controllable properties. Furthermore, HMWG was cationized by dissolving it in acidified deionized water at pH value less than its isoelectric point. Factorial design analysis was utilized to investigate the effect of different preparation variables (viz. HMWG concentration, pH and ratio of HMWG solution volume to non-solvent volume) on particle size, polydispersity index (PDI), zeta potential and yield of GNPs. Results Results revealed the formation of monodisperse GNPs with small particle size, low PDI values (< 0.2) and high yield. FT-IR spectroscopy and differential scanning calorimetry studies revealed that the conformational structure of HMWG chains was altered within GNPs matrices. Conclusion The suggested modifications introduced on the one-step desolvation method enable to prepare successfully monodispersed GNPs with narrow size distribution and high particle yield.

Dye sorption characters of gamma irradiated foamed ethylene propylene diene monomer (EPDM) rubber/clay composites

Mahmoud S. Hassan,Khaled F. El-Nemr 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

Composites based on gamma irradiated ethylene propylene diene monomer rubber in foam structure,loaded with different types of clays were used as adsorbents for different classes of dyestuffs (basic, acid,reactive and disperse) from aqueous solutions. The clays under investigation were Aswan clay (ASC) and sodium montmorillonite (Na-MMT). The effect of adsorbent composition, irradiation dose, pH and contact time on dye sorption was studied. It was found that the rubber composites loaded by Na-MMT gave maximum adsorption of the basic dye (~42%) in aqueous solution, while the rubber composites loaded by AS clay gave maximum adsorption (~28%) of the acidic dye. On the other hand, both type of clays did not show no affinity toward reactive and disperse dyes. The efficiency of dye removal was found to increase with increasing the pH and contact time. It was also observed that the irradiation dose (50 kGy) was the optimum dose for the removal of dyes for all rubber composites.

The impact of magnesium sulfate as adjuvant to intrathecal bupivacaine on intra-operative surgeon satisfaction and postoperative analgesia during laparoscopic gynecological surgery: randomized clinical study

( Khaled Salah Mohamed ),( Sayed Kaoud Abd-elshafy ),( Ali Mahmoud El Saman ) 대한통증학회 2017 The Korean Journal of Pain Vol.30 No.3

Background: Surgeon satisfaction and patient analgesia during the procedure of laparoscopic surgery are important issues. The aim of this work was to study if an intrathecal (IT) Bupivacaine combined with Magnesium sulfate may or may not provide good surgeon satisfaction in addition to improvement of intraoperative and postoperative analgesia. Methods: Sixty female patients were enrolled in this prospective, randomized, double-blind controlled clinical trial study. All patients were operated for gynecological laparoscopic surgery under spinal anesthesia. Patients were divided into two groups (Bupivacaine and Magnesium). Group Bupivacaine (30 patients) received intrathecal Bupivacaine 0.5% only (15 mg), while 30 patients in group Magnesium received intrathecal Bupivacaine (15 mg) in addition to intrathecal Magnesium sulfate (50 mg). The sensory block level, the intensity of motor block, the surgeon satisfaction, the intraoperative visual analog scale (VAS) for pain assessment, the postoperative VAS, and side effects were recorded during the intraoperative period and within the first 24 hours after surgery in the post-anesthesia care unit. Results: Surgeon satisfaction, intraoperative shoulder pain, postoperative pain after 2 h, and perioperative analgesic consumption (ketorolac) were significant better in group Magnesium than in group Bupivacaine. (P < 0.05). The onset of motor and sensory blocks was significant longer in group Magnesium than the other one. The incidence of PONV, pruritus and urinary retention was insignificant statistically between both groups. Conclusions: Magnesium sulfate if used intrathecally as an adjuvant to Bupivacaine would provide a better surgeon satisfaction and would improve the analgesic effect of spinal anesthesia used for gynecological laparoscopic surgery. (Korean J Pain 2017; 30: 207-13)

Activity of Some Hepatic Enzymes in Schistosomiasis and Concomitant Alteration of Arylsulfatase B

( Mahmoud Balbaa ),( Mohamed El Kersh ),( Hamdy Mansour ),( Galila Yacout ),( Mohamed Ismail ),( Ahmed Malky ),( Khaled Bassiouny ),( Nihad Abdel Monem ),( Kamal Kandeel ) 생화학분자생물학회 2004 BMB Reports Vol.37 No.2

The levels of arylsulfatases A and B, α-amylase, aspartate transcarbamylase, and γ-glutamyl transpeptidase were investigated during the infection of mice with schistosoma mansoni. This infection caused a significant (p<0.001) increase in the activity of hepatic arylsulfatases B (ASB), aspartate transcarbamylases and γ-glutamyl transpeptidase. A non-significant difference occurred for a-amylase (p<0.3) and arylsulfatases A(p>0.5) when compared to the control. The specific activity of hepatic ASB was progressively increased with the progression of the Schistosoma-infection. Moreover, the kinetic studies of hepatic ASB in Schistosoma-infection showed that a slight decrease in the value of K_(m) and about a 40% increase in V_(max) when compared to the control. In addition, the pH optimum of hepatic ASB was altered from 6 to 7 as a result of schistosomiasis. These observations suggest that there are schistosomiasis-associated changes of the catalytic and kinetic properties of hepatic ASB.

Petrology and geochemistry of the Az Zabirah south zone bauxite deposit at Al Ba’itha mine, north-central Saudi Arabia

Mahmoud A. Galmed,Hisham A. Gahlan,Habes A. Ghrefat,Essam A. Mohamed,Khaled M. Al Kahtany 한국지질과학협의회 2024 Geosciences Journal Vol.28 No.3

In the central north of Saudi Arabia, outcrop samples from the Cretaceous bauxite profile deposits in the Az Zabirah area were subjected to a comprehensive evaluation aimed at investigating their petrographical and geochemical characteristics using X-ray diffraction analysis (XRD), Scanning electron microscope (SEM) coupled with Energy dispersive (EDS) analysis, and X-ray fluorescence spectrometer (XRF) analysis. These bauxite deposits in the Az Zabirah area comprises of three main zones: the South zone, the Central zone, and the North zone. Petrologically, the bauxite samples predominantly consist of oolitic to pisolitic grains that are bound together by a matrix comprising bauxitic materials, iron oxides, calcite, and/or kaolinite. Mineralogical investigations indicate that the primary mineral composition of the bauxite includes gibbsite, boehmite, diaspore (kaolinite), hematite, quartz, and calcite. XRF showed that the dominant chemical components of the bauxite samples are Al2O3, SiO2, and Fe2O3. When considering the collective data from the rare earth elements (REEs) analysis (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and chemical weathering indices such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Weathering Index of Parker (WIP), it becomes evident that the Az Zabirah South Zone bauxite laterite profile at Al Ba’itha mine was formed under the influence of significant and persistent weathering conditions. The findings and methods used in this study are considered beneficial and valuable as they support mineral exploration in arid and semi-arid environments.

Activity of Some Hepatic Enzymes in Schistosomiasis and Concomitant Alteration of Arylsulfatase B

Balbaa, Mahmoud,El-Kersh, Mohamed,Mansour, Hamdy,Yacout, Galila,Ismail, Mohamed,Malky, Ahmed,Bassiouny, Khaled,Abdel-Monem, Nihad,Kandeel, Kamal Korean Society for Biochemistry and Molecular Biol 2004 Journal of biochemistry and molecular biology Vol.37 No.2

The levels of arylsulfatases A and B, $\alpha$-amylase, aspartate transcarbamylase, and $\gamma$-glutamyl transpeptidase were investigated during the infection of mice with schistosoma mansoni. This infection caused a significant (p<0.001) increase in the activity of hepatic arylsulfatase B (ASB), aspartate transcarbamylases and $\gamma$-glutamyl transpeptidase. A non-significant difference occurred for $\alpha$-amylase (p<0.3) and arylsulfatase A (p>0.5) when compared to the control. The specific activity of hepatic ASB was progressively increased with the progression of the Schistosoma-infection. Moreover, the kinetic studies of hepatic ASB in Schistosoma-infection showed that a slight decrease in the value of $K_m$ and about a 40% increase in $V_{max}$ when compared to the control. In addition, the pH optimum of hepatic ASB was altered from 6 to 7 as a result of schistosomiasis. These observations suggest that there are schistosomiasis-associated changes of the catalytic and kinetic properties of hepatic ASB.

Egyptian Honeybee Pollen as Antimicrobial, Antioxidant Agents, and Dietary Food Supplements

Manal Khider,Khaled Elbanna,Awad Mahmoud,Ayman A. Owayss 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.5

In this study, three Egyptian bee pollen types from different plant sources, namely maize (Zea mays),clover (Trifolium alexandrinum), and date palm (Phoenix dactylifera), were evaluated as natural antimicrobial agents,antioxidants, and food additives. A methanolic extract of maize bee pollen exhibited the highest antibacterial activity,followed by clover and date palm bee pollen. Staphylococcus aureus and Escherichia coli were the most sensitive,followed by Listeria monocytogenes, Salmonella enteritidis,and Pseudomonas aeruginosa. In ghee, all methanolic extracts, especially that of maize bee pollen, showed high antioxidant activities as radical scavenger substances and as inhibitors of lipid peroxidation. Sensory evaluation of yoghurt supplemented with different bee pollens revealed that maize bee pollen improve texture, increased gel strength, and decreased syneresis and had favorable nutty flavor, while clover and date palm pollen added a sweet taste and bean-like flavor, respectively. These findings establish the potential of Egyptian maize and clover bee pollen as antioxidants, antimicrobial agents, promising natural food supplements, and natural preservatives.

A novel refined plate theory for stability analysis of hybrid and symmetric S-FGM plates

Fouad Bourada,Khaled Amara,Abdelmoumen A. Bousahla,Abdelouahed Tounsi,S. R. Mahmoud 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.6

In this paper, buckling analysis of hybrid functionally graded plates using a novel four variable refined plate theory is presented. In this theory the distribution of transverse shear deformation is parabolic across the thickness of the plate by satisfying the surface conditions. Therefore, it is unnecessary to use a shear correction factor. The variations of properties of the plate through the thickness are according to a symmetric sigmoid law (symmetric S-FGM). The principle virtual works is used herein to extract equilibrium equations. The analytical solution is determined using the Navier method for a simply supported rectangular plate subjected to axial forces. The precision of this theory is verified by comparing it with the various solutions available in the literature.