Synthesis, Fastness and Spectral Properties of Some New Azo Pyrazole and Pyrazolotriazole Derivatives

Rizk, Hala F.,El-Badawi, Mahmoud A.,Ibrahim, Seham A.,El-Borai, Mohamed A. Korean Chemical Society 2010 대한화학회지 Vol.54 No.6

Coupling of 5-amino-1,3-diaryl-pyrazoles 1a-c with diazonium salts of different aryl amines gave a series of novel 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l. Such compounds could be also obtained by reaction of 5-amino-1,3-diaryl-4-nitroso- 1H-pyrazoles 2a-c with different aryl amines in alkaline medium. Oxidation of azo derivatives 3a-l with cupric acetate, in dimethyl formamide and stream of air, gave 2,4,6-triaryl-2,4-dihydropyrazolo [4,3-d]-1,2,3-triazoles 4a-l. and the fluorescence properties of the cyclic triazoles were studied. Diazotization of 5-amino-1,3-diaryl-1H-pyrazoles 1a-c by sodium nitrite in ortho-phosphoric acid followed by coupling with some aryl amines gave o-aminoazo compounds 5a-f. Cyclisation of compounds 5a-f in pyridine and cupric acetate gave the corresponding triazoles 6a-f. The coupling of compounds 6a-f with different aryl diazonium salts gave compounds 7a-j. The synthesized dyes were applied to polyesters as disperse dyes and the fastness properties were evaluated. 5-Amino-1,3-diaryl-pyrazoles 1a-c 와 다양한 aryl amine의diazonium salts를 반응시켜서 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l을 합성하였으며, 몇 가지 화합물은 5-amino-1,3-diaryl-4-nitroso-1H-pyrazoles 2a-c와 aryl amine의 diazonium salts를 반응시켜서 얻었다. 합성한 azo 유도체 화합물 3a-l을 DMF 용매 속에서 cupric acetate와 산화반응시켜서 2,4,6-triaryl-2,4-dihydropyrazolo [4,3-d]-1,2,3-triazoles 4a-l을 합성하였으며, 합성한 cyclic triazoles에 대한 형광 특성을 측정하였다. 한편, Diazotization of sodium nitrite/ortho-phosphoric acid 조건에서 5-amino-1,3-diaryl-1H-pyrazoles 1a-c를 diazotization화 반응시킨 다음에, aryl amines과 반응시켜서 o-aminoazo compounds 5a-f를 합성하였다. 합성한 화합물 5a-f를 pyridine/cupric acetate 반응 조건에서 반응시켜서 triazole 6a-f들을 합성하였으며, 얻어진 화합물 6a-f을 aryl diazonium salts과 반응시켜서 화합물 7a-j을 합성하였다. 합성한 염료 화합물을 polyesters에 분산염료와 정착성을 측정하였다.

A novel barium oxide-based Iraqi sand glass to attenuate the low gamma-ray energies: Fabrication, mechanical, and radiation protection capacity evaluation

Al-Saeedi F.H.F.,Sayyed M.I.,Kapustin F.L.,Al-Ghamdi Hanan,Kolobkova E.V.,Tashlykov O.L.,Almuqrin Aljawhara H.,Mahmoud K.A. 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

In the present work, untreated Iraqi sand with grain sizes varied between 100 and 200 mm was used to produce a colored glass sample that has shielding features against the low gamma-ray energy. Therefore, a weight of 70e60 wt % sand was mixed with 9e14 wt% B2O3, 8e10 wt% Na2O, 4e6 wt% of CaO, 3e6 wt% Al2O3, in addition to 0.3% of Co2O3. After melting and annealing the glass sample, the X-ray diffraction spectrometry was applied to affirm the amorphous phase of the fabricated glass samples. Moreover, the X-ray dispersive energy spectrometry was used to measure the chemical composition, and the MH-300A densimeter was applied to measure the fabricated sample's density. The Makishima-Makinzie model was applied to predict the mechanical properties of the fabricated glass. Besides, the Monte Carlo simulation was used to estimate the fabricated glass sample's radiation shielding capacity in the low-energy region between 22.1 and 160.6 keV. Therefore, the simulated linear attenuation coefficient changed between 10.725 and 0.484 cm1 , raising the gamma-ray energy between 22.1 and 160.6 keV. Also, other shielding parameters such as a half-value layer, pure lead equivalent thickness, and buildup factors were calculated

Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate

Mahmoud, Amer F.,Hassan, Mohamed I.,Amein, Karam A. The Korean Society of Plant Pathology 2015 Plant Pathology Journal Vol.31 No.4

Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 <9 with an average of 7.29, which exceeded the Egyptian bread wheat cultivar Giza-168 (5.58). Thirty three RILs were included among the acceptable range having RRI value >2 <6. However, only 7 RILs showed RRI value <2. Five RILs expressed hypersensitive type of resistance (R) against the pathogen and showed the lowest Average Coefficient of Infection (ACI). Bulked segregant analysis (BSA) with eight simple sequence repeat (SSR), eight sequence-related amplified polymorphism (SRAP) and sixteen random amplified polymorphic DNA (RAPD) markers revealed that three SSR, three SRAP and six RAPD markers were found to be associated with the resistance to yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

Genetic Variation and Biological Control of Fusarium graminearum Isolated from Wheat in Assiut-Egypt

Amer F. Mahmoud 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.2

Fusarium graminearum Schwabe causes Fusarium headblight (FHB), a devastating disease that leads to extensiveyield and quality loss of wheat and other cerealcrops. Twelve isolates of F. graminearum were collectedfrom naturally infected spikes of wheat from AssiutEgypt. These isolates were compared using SRAP. Theresults indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups havedifferent biological properties, especially with respectto their pathogenicity on wheat. There were biologicallysignificant differences between the groups; withgroup (B) isolates being more aggressive towards wheatthan groups (A) and (C). Furthermore, Trichodermaharzianum (Rifai) and Bacillus subtilis (Ehrenberg)which isolated from wheat kernels were screened forantagonistic activity against F. graminearum. Theysignificantly reduced the growth of F. graminearumcolonies in culture. In order to gain insight into biologicalcontrol effect in situ, highly antagonistic isolates ofT. harzianum and B. subtilis were selected, based ontheir in vitro effectiveness, for greenhouse test. It wasrevealed that T. harzianum and B. subtilis significantlyreduced FHB severity. The obtained results indicatedthat T. harzianum and B. subtilis are very effective biocontrolagents that offer potential benefit in FHB andshould be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studiesof population structures have significant implicationsfor understanding the genetic traits and disease controlprograms in wheat. This is the first known report of thedistribution and genetic variation of F. graminearum onwheat spikes in Assiut Egypt.

Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate

Amer F. Mahmoud,Mohamed I. Hassan,Karam A. Amein 한국식물병리학회 2015 Plant Pathology Journal Vol.31 No.4

Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 <9 with an average of 7.29, which exceeded the Egyptian bread wheat cultivar Giza-168 (5.58). Thirty three RILs were included among the acceptable range having RRI value >2 <6. However, only 7 RILs showed RRI value <2. Five RILs expressed hypersensitive type of resistance (R) against the pathogen and showed the lowest Average Coefficient of Infection (ACI). Bulked segregant analysis (BSA) with eight simple sequence repeat (SSR), eight sequence-related amplified polymorphism (SRAP) and sixteen random amplified polymorphic DNA (RAPD) markers revealed that three SSR, three SRAP and six RAPD markers were found to be associated with the resistance to yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

Genetic Variation and Biological Control of Fusarium graminearum Isolated from Wheat in Assiut-Egypt

Mahmoud, Amer F. The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.2

Fusarium graminearum Schwabe causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss of wheat and other cereal crops. Twelve isolates of F. graminearum were collected from naturally infected spikes of wheat from Assiut Egypt. These isolates were compared using SRAP. The results indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups have different biological properties, especially with respect to their pathogenicity on wheat. There were biologically significant differences between the groups; with group (B) isolates being more aggressive towards wheat than groups (A) and (C). Furthermore, Trichoderma harzianum (Rifai) and Bacillus subtilis (Ehrenberg) which isolated from wheat kernels were screened for antagonistic activity against F. graminearum. They significantly reduced the growth of F. graminearum colonies in culture. In order to gain insight into biological control effect in situ, highly antagonistic isolates of T. harzianum and B. subtilis were selected, based on their in vitro effectiveness, for greenhouse test. It was revealed that T. harzianum and B. subtilis significantly reduced FHB severity. The obtained results indicated that T. harzianum and B. subtilis are very effective biocontrol agents that offer potential benefit in FHB and should be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studies of population structures have significant implications for understanding the genetic traits and disease control programs in wheat. This is the first known report of the distribution and genetic variation of F. graminearum on wheat spikes in Assiut Egypt.

Optimal shape design of contact systems

Mahmoud, F.F.,El-Shafei, A.G.,Al-Saeed, M.M. Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.24 No.2

Many applications in mechanical design involve elastic bodies coming into contact under the action of the applied load. The distribution of the contact pressure throughout the contact interface plays an important role in the performance of the contact system. In many applications, it is desirable to minimize the maximum contact pressure or to have an approximately uniform contact pressure distribution. Such requirements can be attained through a proper design of the initial surfaces of the contacting bodies. This problem involves a combination of two disciplines, contact mechanics and shape optimization. Therefore, the objective of the present paper is to develop an integrated procedure capable of evaluating the optimal shape of contacting bodies. The adaptive incremental convex programming method is adopted to solve the contact problem, while the augmented Lagrange multiplier method is used to control the shape optimization procedure. Further, to accommodate the manufacturing requirements, surface parameterization is considered. The proposed procedure is applied to a couple of problems, with different geometry and boundary conditions, to demonstrate the efficiency and versatility of the proposed procedure.

Nonlocal finite element modeling of the tribological behavior of nano-structured materials

Mahmoud, F.F.,Meletis, E.I. Techno-Press 2010 Interaction and multiscale mechanics Vol.3 No.3

A nonlocal finite element model is developed for solving elasto-static frictional contact problems of nanostructures and nanoscale devices. A two dimensional Eringen-type nonlocal elasticity model is adopted. The material is characterized by a stress-strain constitutive relation of a convolution integral form whose kernel is capable to take into account both the diffusion process of nonlocal elasticity and the scale ratio effects. The incremental convex programming procedure is exploited as a solver. Two examples of different nature are presented, the first one presents the behavior of a nanoscale contacting system and the second example discusses the nano-indentation problem.

Efficient optimal design of passive structural control applied to isolator design

Kamalzare, Mahmoud,Johnson, Erik A.,Wojtkiewicz, Steven F. Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Typical base isolated buildings are designed so that the superstructure remains elastic in design-level earthquakes, though the isolation layer is often quite nonlinear using, e.g., hysteretic elements such as lead-rubber bearings and friction pendulum bearings. Similarly, other well-performing structural control systems keep the structure within the linear range except during the most extreme of excitations. Design optimization of these isolators or other structural control systems requires computationally-expensive response simulations of the (mostly or fully) linear structural system with the nonlinear structural control devices. Standard nonlinear structural analysis algorithms ignore the localized nature of these nonlinearities when computing responses. This paper proposes an approach for the computationally-efficient optimal design of passive isolators by extending a methodology previously developed by the authors for accelerating the response calculation of mostly linear systems with local features (linear or nonlinear, deterministic or random). The methodology is explained and applied to a numerical example of a base isolated building with a hysteretic isolation layer. The computational efficiency of the proposed approach is shown to be significant for this simple problem, and is expected to be even more dramatic for more complex systems.

A Protective Mechanism in Lungs of Rats Experimentally Infected with Aspergillus fumigatus

( Yehia A G. Mahmoud ),( Abdulaziz Yahya Al Ghamdi ),( Eman H. F. Abd El Zaher ) 한국균학회 2011 Mycobiology Vol.39 No.1

Aspergillus fumigatus is associated with invasive disease aspergillosis in immunocompromised individuals. The major aim of this study was to investigate the biochemical and immunological responses of male Wistar rats against A. fumigatus experimentally-induced pulmonary fungal infection. Nostril experimental exposure of male Wistar rats to a high dose of A. fumigatus freeze-dried preparation for only 24 hr resulted in a significant increase in levels of catalase, nitric oxide and lipid peroxide in lung homogenates, compared to those of the control animals. However, the oxidative status of the lungs of rats challenged with killed fungus did not change significantly, except for the stimulation in the level of lipid peroxide. IgG level was significantly elevated only in rats that received two low doses of fungus, compared to unexposed animals (p < 0.005). Examining the lung of rats exposed to A. fumigatus revealed no abnormal changes, except for pus in bronchial lumen spaces and per bronchial inflammation. Histologically, large numbers of granuloma cells were evident in the lungs of challenged rats, while no granuloma formation was evident in the lungs of rats exposed to killed fungus.