Wyniki wyszukiwania - Biblioteka Nauki

1

Study the internal cracks effect on vibration of laminated composite square plates

100%

Hassan M. S. , Rashid Z. H. , Sarhan R. A.

Archives of Materials Science and Engineering

|

2022

|

tom Vol. 116, nr 1

28--33

EN

Purpose: The study of cracks behaviour in a composite plate is of significant importance in the dynamics of the Mechanical parts in order to avoid design failures due to resonance or high amplitude vibrations. Design/methodology/approach: In this paper, a square glass-epoxy composite plate is adopted. The plate has four layers with symmetric and asymmetric lamination. Assuming the cracks are profound as defects. The results were obtained by using a numerical solution of mechanical APDL from ANSYS. Findings: It has been found for different boundary conditions that the rank of natural frequencies is decreased by increasing the crack ratio due to the reduction of the plate’s stiffness, whereas the crack direction has no mentioned effect for a small angle of rotation. Research limitations/implications: The accuracy of results is verified by comparing a single case of the current work with other previous investigations. value: Evaluate the influence of the crack length ratio, angle of the crack rotation, boundary conditions and lamination angles on the natural frequencies of the square composite plate with glass-epoxy materials.

2

Triiodothyronine (T3) levels in serum of the female Egyptian buffaloes at different seasons and reproductive status

100%

El-Nemr I. Z. , Younis A. A. , Mansour M. A. , Hassan M. S.

Annals of Warsaw Agricultural University. Veterinary Medicine

|

1990

|

tom 16

3

Effects of aluminum (Al) incorporation on structural, optical and thermal properties of ZnO nanoparticles

100%

Ahammed N. , Hassan M. S. , Hassan M.

Materials Science Poland

|

2018

|

tom Vol. 36, No. 3

419--426

EN

In this research article, pure and 1 %, 3 % and 5 % aluminium doped zinc oxide nanoparticles (NPs) were prepared via sol-gel method and then calcined at 500 °C. X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques were used to investigate the structural, optical and thermal properties of synthesized pure and Al doped ZnO nanoparticles. Energy dispersive X-ray spectroscopy (EDX) analysis revealed high purity of nanoparticles in the synthesized products without any impurity peaks. Mean dimension of the nanoparticles was ~28 nm and they were hexagonal in shape, according to the images analyzed by transmission electron microscope (TEM). The optical absorption spectra of pure and Al doped ZnO samples studied using UV-Vis spectrometry have been presented and we have observed that the band gap increases with increasing Al concentration. In FT-IR spectra, the broad absorption peaks around 485 cm-1 and 670 cm cm-1 were assigned to Zn–O vibration. Above 450 °C, the TG curve became flat what means there was no weight loss. In the DSC curve it is seen that the transition at 150 °C was highly exothermic because of structural relaxation and on doping the exothermic peaks became shifted to the lower value of temperature. These types of materials are very useful in optoelectronics applications.

4

Mineralogical study and enhanced gravity separation of gold-bearing mineral, South Eastern Desert, Egypt

75%

El-Sayed S. , Abdel-Khalek N. A. , El-Shatoury E. H. , Abdel-Motelib A. , Hassan M. S. , Abdel-Khalek M. A.

Physicochemical Problems of Mineral Processing

|

2020

|

tom Vol. 56, iss. 5

839--848

EN

El-Hudi gold deposit, located in the South Eastern Desert of Egypt, represent large vein- type gold occurrence. The representative sample revealed the abundance of quartz as main constituent with minor amounts of mineral impurities. Gold was detectable (12 g/t) as determined using atomic absorption. The petrographic study revealed that the gold grains ranged from 10-40 μm. The grain boundaries of quartz are highly stained with iron minerals as hematite and limonite. Sericite mineral is common in discrete gold-bearing veins. Eroded pyrite was detected with high alteration leaving only cubic-shaped cavities behind. Different techniques for gravity separation were used to separate gold from the quartz mineral. After crushing and grinding of the sample, shaking table was used to upgrade the coarser fractions while Falcon concentrator was employed to upgrade the fine fraction. The best concentrate was obtained through grinding the whole sample to less than 0.2 mm, followed by cleaning steps. The gold content is increased from 12 to 145 g/t with total recovery of 78%.

5

Influence of probiotic and yeast culture supplementation on selected biochemical and immunological parameters of growing lambs

63%

Mahmoud M. M. , Youssef I. M. I. , Abd El-Tawab M. M. , Bakr H. A. , Eissa N. A. , Hassan M. S. , Giadinis N. D. , Milewski S. , Baumgartner W. , Sobiech P.

Polish Journal of Veterinary Sciences

|

2020

|

tom 23

|

nr 1

6

Influence of probiotic and yeast culture supplementation on selected biochemical and immunological parameters of growing lambs

63%

Mahmoud M. M. , Youssef I. M. I. , Abd El-Tawab M. M. , Bakr H. A. , Eissa N. A. , Hassan M. S. , Giadinis N. D. , Milewski S. , Baumgartner W. , Sobiech P. , Mahmoud M. M. , Youssef I. M. I. , Abd El-Tawab M. M. , Bakr H. A. , Eissa N. A. , Hassan M. S. , Giadinis N. D. , Milewski S. , Baumgartner W. , Sobiech P.

|