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31.
Abdelmagid Hamed Sanaa Ragaee El‐Sayed M. Abdel‐Aal 《Journal of food science》2014,79(12):E2470-E2479
Research has shown that prolonged frozen storage of bread dough reduces the quality of the end product. In this study, the effect of air‐classified barley flour fraction rich in β‐glucan (approximately 25%) on rheology and quality of frozen yeasted bread dough was investigated. Wheat flour (W) was replaced by air‐classified barley flour fraction (B) at 10% without or with 1.4% vital gluten to produce β‐glucan enriched barley dough (WB) or barley dough plus gluten (WB + G). Dough products were stored at ?18 ºC for 8 wk and their rheological properties were investigated weekly. During frozen storage dough extensibility increased, while elastic and viscous moduli decreased. Differential scanning calorimeter and nuclear magnetic resonance data indicated that WB and WB + G dough products contained approximately 10% less freezable water and 9% more bound water compared to the control dough (W). β‐Glucan enriched dough also exhibited less changes in gluten network as shown by SEM photographs. The addition of air‐classified barley flour fraction at 10% in frozen dough reduced deterioration effects caused by frozen storage via minimizing water redistribution and maintaining rheological properties of frozen dough. 相似文献
32.
Samia E. Abdel‐Aal El‐Sayed A. Hegazy M. F. Abou Taleb Ahmed M. Dessouki 《应用聚合物科学杂志》2008,107(3):1759-1776
Radiation‐crosslinked 2‐hydroxyethylmethacrylate/citric acid (HEMA/CAc), 2‐hydroxyethylmethacrylate/tartaric acid (HEMA/TA), and 2‐hydroxyethylmethacrylate/succinic acid (HEMA/Sc) copolymers were prepared by using 60Co γ‐rays. The gel fraction yield and the swelling behavior of the prepared hydrogels were studied. It was shown that increasing irradiation doses was accompanied by an increase in yield of gel fraction and a decrease in swelling degree. The parameters of equilibrium swelling, maximum swelling, initial swelling rate, swelling exponent, and diffusion coefficient of the hydrogels were determined by studying the swelling behavior of the hydrogels prepared. It was seen that the equilibrium swelling degree increases as the content of acid increases, as a result of introducing more hydrophilic groups. When the hydrophilic polymer (acids) varies in the content range of 40–80 mg, swelling exponents (n) decreases, thereby indicating a shift in the water‐transport mechanism from the anomalous (non‐Fickian)‐type to the Fickian‐type. Characterization and some selected properties of the prepared hydrogels were studied, and accordingly the possibility of its practical use in the treatment of industrial wastes such as dyes and heavy metals (Fe, Ni, Co, and Cu) were also studied. The effect of treatment time, pH of feed solution, initial feed concentration, and temperature on the dye and heavy metals uptake was determined. The uptake order for a given metal was HEMA/TA hydrogel > HEMA/CAc > HEMA/Sc hydrogel. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
33.
Mohamed Ibrahim Abd El Aal Nahed El Mahallawy Farouk A. Shehata Mohamed Abd El Hameed Eun Yoo Yoon Jung Hwan Lee Hyoung Seop Kim 《Metals and Materials International》2010,16(5):709-716
In the present paper, billets of pure Al, and cast-homogenized Al-2 wt.%, 3 wt.%, and 5 wt.% Cu alloys were successfully processed
by equal channel angular pressing (ECAP) up to 10 passes without fracture at room temperature using a die with a channel angle
of 110°. Giant strains imposed on workpieces lead to extreme dislocation densities, microstructural refinement, and finally
ultrafine grained materials. Tensile tests were employed to examine the fracture modes and fracture surface morphologies of
the ECAP-processed Al and Al-Cu alloy samples. In particular, the effects of the number of ECAP passes and the Cu content
were investigated. 相似文献
34.
Alsayed Abdel Aal Rihab Al-Salman Mohammad Al-Zoubi Natalia Borissenko Frank Endres Oliver Höfft Alexandra Prowald Sherif Zein El Abedin 《Electrochimica acta》2011,(28):10295
In this paper we report on recent results from our group, namely on the interface ionic liquid/electrode, plasma electrochemistry and electrodeposition of selenium and of macroporous structures. Ionic liquids show an interesting and liquid dependent surface chemistry: in some liquids the long range “herringbone” superstructure of Au(1 1 1) is visible, in others it is not. Glow discharge plasmas can be employed as a contact free electrode to make nanoparticles in solutions, e.g. nanoparticles of germanium. Selenium can be electrodeposited from ionic liquids under environmental conditions in an open cell and both the red and the grey phases of selenium are feasible. With the help of self organized opal structures of polystyrene spheres macroporous materials of Ag, Al and conducting polymers can be made. The prospects and limits of ionic liquids in surface electrochemistry and electrodeposition are shortly discussed. 相似文献
35.
A.S. Shalabi S. Abdel Aal M.M. Assem W.S. Abdel Halim 《International Journal of Hydrogen Energy》2013
Characterization has been performed on basis of several physicochemical parameters. The results indicate that the preferential adsorption is on Ti atom deposited on the top site of the (5,5) armchair SWCNT with energies (−0.44 and −0.71) eV for H2 oriented parallel to the (x) and (y) axes respectively. The binding of H2 is mostly dominated by the support-metal E (i)S?Ti term. The role of the SWCNT is not restricted to support the metal. Significant reduction of the energy gap is observed when H2 are anchored on the external surface of the SWCNT. The SWCNT?Ti?H2(x) complex is the least reactive configuration with nucleophiles. The calculated parameters characterize H2 that is oriented parallel to the (x)-[100] axis of the SWCNT to be the most suitable configuration for hydrogen storage based on the recommended adsorption energy range of DOE (−0.2 to −0.6) eV. 相似文献
36.
Eun Yoo Yoon Dong Jun Lee Lee Ju Park Sunghak Lee Mohamed Ibrahim Abd El Aal Hyoung Seop Kim 《Metallurgical and Materials Transactions A》2014,45(11):4748-4752
High tensile strength of 616 MPa and improved ductility of 7.6 pct were obtained in powder-consolidated pure Cu processed by high-pressure torsion (HPT) at room temperature followed by post-annealing at 673 K (400 °C). The powder-HPT consolidation process maintained nano-crystalline microstructures even after post-annealing due to the presence of well-dispersed oxide particles in the matrix. Higher ductility in the post-annealed specimen is attributed to higher fraction of stable Σ3 coincidence site lattice boundaries than that in the HPT-processed Cu. 相似文献
37.
Nadia?Abdel?Aal Faten?Al-Hazmi Ahmed?A.?Al-Ghamdi Attieh?A. Al-Ghamdi Farid?El-Tantawy F.?YakuphanogluEmail author 《Microsystem Technologies》2015,21(10):2155-2163
Nano-structured graphene oxide (GO) freestanding paper was synthesized by an arc recharge technique in flowing of oxygen for the first time. This technique offers new ways on how e.g. layers structure nanomaterials could be produced. The morphology and structural properties of the as-synthesized GO were examined by means of X-ray diffraction, Fourier transform infrared spectra, scanning electrom microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy and selective area electron diffraction techniques. The structural and morphological characterizations revealed that the synthesized GO were well-defined nanosheets with a thickness of 6 nm. The optical band gap was calculated from the absorption spectrum, and was found to be 3.32 eV. Furthermore, we aim to use GO paper to develop new electromagnetic interference shielding sheets that have a high shielding effectiveness (SE) (over 30 dB) at frequencies in the 1–12 GHz range. The complex permittivity and total shielding effectiveness of as synthesized GO freestanding paper are measured at frequencies from 1 to 12 GHz. Finally, to enhance the performances of the electromagnetic shields effectiveness, five-layered GO sheets were made. Furthermore, the highest SE for the light-weight freestanding GO paper was 50 dB at 1 GHz, indicating commercial use for many industrial or military shielding applications as an attractive candidate for the new type of microwave shielding. 相似文献
38.
A. Abdel Aal 《Journal of Materials Science》2008,43(8):2947-2954
A phosphate–permanganate conversion coating was applied as the pretreatment process for AZ91D magnesium alloy substrate. Zn–Ni
alloys were electrodeposited onto the treated AZ91D magnesium alloy from sulfate bath. The morphology and phase composition
of the coatings were determined with X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The results reveal that
the conversion rate depends on pH of solution and treatment time. Salt spray and the electrochemical polarization testing
were applied to evaluate the corrosion performance of phosphate–permanganate and Zn–Ni coated alloys. It was found that Ni
content in deposit is a function of current density and bath composition. Zn–13 wt.% Ni coating provides very good corrosion
protective function to inner AZ91D magnesium alloy. Phosphate–permanganate treatment enhances the corrosion resistance of
Zn–Ni coatings. 相似文献
39.
Cyclic voltammograms (CVs) of the Ni electrode are traced in Na2B4O7 solutions as a function of electrolyte concentration, voltage scanning range, and rate in order to determine the nature of
failure protective species formed in the slightly alkaline media. The species formed on the Ni electrode are found to depend
on the sweep number due to changes in the activation state of the electrode surface. The voltammograms are characterized by
a pronounced anodic peak due to the formation of NiO and a protective passive film corresponding to the formation of β-Ni(OH)2 before the evolution of oxygen. An additional anodic peak in the vicinity of oxygen evolution potential appeared in the advanced
cycles that is attributed to the transformation of β-Ni(OH)2 to β-NiOOH. The cathodic branch shows only one peak corresponding to the reduction of β-NiOOH to β-Ni(OH)2. The current density flowing along the anodic oxidation peak varies with the concentration of the electrolyte according to:
where a and b are constants. An increase in the scan rate increases markedly the current density flowing along the whole range of the CVs.
As the concentration of borate anions increases, the anodic peak potential is shifted toward more positive values, whereas
the cathodic peak potential is shifted in the negative direction, indicating the irreversibility of formation of the passive
film formed on the electrode surface. A correlation is made between the anodic oxidation processes and their corresponding
cathodic one. The failure-protecting film in borate solutions is assumed to be caused by the formation of a sandwich oxide
having the form: NiO/β-Ni(OH)2/β-NiOOH. 相似文献
40.
Two different hydrogels, prepared from N‐vinyl‐2‐pyrrolidone/acrylic acid (NVP/AAc) and N‐vinyl‐2‐pyrrolidone/acrylamide (NVP/AAm), were studied for the separation and extraction of some heavy‐metal ions from wastewater. The hydrogels were prepared by the γ‐radiation‐induced copolymerization of the aforementioned binary monomer mixtures. Further modification was carried out for the NVP/AAc copolymer through an alkaline treatment to improve the swelling behavior by the conversion of the carboxylic acid groups into its sodium salts. The thermal stability and swelling properties were also investigated as functions of the N‐vinyl‐2‐pyrrolidone content. The characterization and some selected properties of the prepared hydrogels were studied, and the possibility of their practical use in wastewater treatment for heavy metals such as Cu, Ni, Co, and Cr was investigated. The maximum uptake for a given metal was higher for a treated NVP/AAc hydrogel than for an untreated NVP/AAc hydrogel and was higher for an untreated NVP/AAc hydrogel than for an NVP/AAm hydrogel. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2642–2652, 2004 相似文献