Discrimination of inland and coastal dunes in Eastern Saudi Arabia desert system: An approach from particle size and textural parameter variations

2016 ◽  
Vol 117 ◽  
pp. 102-113 ◽  
Author(s):  
Ardiansyah Koeshidayatullah ◽  
Septriandi Asmaidi Chan ◽  
Majed Al-Ghamdi ◽  
Tariq Akif ◽  
Khalid Al-Ramadan
Keyword(s):  
Particle Size ◽  
Saudi Arabia ◽  
Coastal Dunes ◽  
Parameter Variations ◽  
Textural Parameter

Particle size distribution measurements at Hada Al Sham, western Saudi Arabia

2013 ◽  
Author(s):  
A.-P. Hyvärinen ◽  
H. Al-Jeelani ◽  
M. Alghamdi ◽  
T. Hussein ◽  
M. Khodeir ◽  
...  
Keyword(s):  
Particle Size ◽  
Saudi Arabia ◽  
Particle Size Distribution ◽  
Size Distribution

scholarly journals Green synthesis, characterization, and antimicrobial activity of silver nanoparticles prepared using Trigonella foenum-graecum L. leaves grown in Saudi Arabia

2021 ◽  
Vol 10 (1) ◽  
pp. 421-429
Author(s):  
Humaira Rizwana ◽  
Mona S. Alwhibi ◽  
Hadeel A. Aldarsone ◽  
Manal Ahmed Awad ◽  
Dina A. Soliman ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Saudi Arabia ◽  
Green Synthesis ◽  
Antimicrobial Agents ◽  
Average Particle Size ◽  
Antimicrobial Activities ◽  
Average Particle ◽  
Pathogenic Yeast ◽  
Trigonella Foenum Graecum L

Abstract Silver nanoparticles (AgNPs) are widely used for medical applications particularly as antimicrobial agents against multidrug-resistant microbial strains. Some plants stimulate the reduction of Ag ions to AgNPs. In this study, we prepared AgNPs via the green synthesis approach using fenugreek leaves grown in Saudi Arabia. Furthermore, we characterized these AgNPs and evaluated their antimicrobial activities against pathogenic yeast, bacteria, and fungi. The ultraviolet-visible peak at 380 nm confirmed the biosynthesis of NPs. Transmission electron microscopy analyses revealed particle size in the range of 9–57 nm with a spherical shape. Dynamic light scattering results confirm slight aggregation as the average particle size was shown as 68.71 nm and a polydispersity index of 0.083. The energy-dispersive X-ray spectroscopy results showed an intense peak at 3 keV, indicating the presence of elemental AgNPs. The synthesized AgNPs efficiently inhibit the growth of both Gram-positive and Gram-negative bacteria; however, varying degree of inhibition was shown toward fungi. The potent antimicrobial ability of the synthesized NPs can be attributed to their small size and round shape. Among all test organisms, the growth of Candida albicans and Helminthosporium sativum was remarkably affected by AgNPs treatment.

Particle size-pediment slope relations: some findings from Saudi Arabia

CATENA ◽  
1995 ◽  
Vol 24 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Peter Vincent ◽  
Ahmad Sadah
Keyword(s):  
Particle Size ◽  
Saudi Arabia

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Confidence toward vaccination as reported by parents of children admitted to a tertiary care hospital in Riyadh, Saudi Arabia: A cross sectional study

Vacunas ◽  
2020 ◽  
Vol 21 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Y.M. AlGoraini ◽  
N.N. AlDujayn ◽  
M.A. AlRasheed ◽  
Y.E. Bashawri ◽  
S.S. Alsubaie ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Cross Sectional Study ◽  
Care Hospital ◽  
Sectional Study ◽  
Cross Sectional
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