1,790 research outputs found
Characterization of highly-oriented ferroelectric Pb_xBa_(1-x)TiO_3
Pb_xBa_(1-x)TiO_3 (0.2 ≾ x ≾ 1) thin films were deposited on single-crystal MgO as well as amorphous Si_3N_4/Si substrates using biaxially textured MgO buffer templates, grown by ion beam-assisted deposition (IBAD). The ferroelectric films were stoichiometric and highly oriented, with only (001) and (100) orientations evident in x-ray diffraction (XRD) scans. Films on biaxially textured templates had smaller grains (60 nm average) than those deposited on single-crystal MgO (300 nm average). Electron backscatter diffraction (EBSD) has been used to study the microtexture on both types of substrates and the results were consistent with x-ray pole figures and transmission electron microscopy (TEM) micrographs that indicated the presence of 90° domain boundaries, twins, in films deposited on single-crystal MgO substrates. In contrast, films on biaxially textured substrates consisted of small single-domain grains that were either c or a oriented. The surface-sensitive EBSD technique was used to measure the tetragonal tilt angle as well as in-plane and out-of-plane texture. High-temperature x-ray diffraction (HTXRD) of films with 90° domain walls indicated large changes, as much as 60%, in the c and a domain fractions with temperature, while such changes were not observed for Pb_xBa_(1-x)TiO_3 (PBT) films on biaxially textured MgO/Si_3N_4/Si substrates, which lacked 90° domain boundaries
The Quark-Gluon Plasma Equation of State and The Generalized Uncertainty Principle
The quark-gluon plasma (QGP) equation of state within a minimal length
scenario or Generalized Uncertainty Principle (GUP) is studied. The Generalized
Uncertainty Principle is implemented on deriving the thermodynamics of ideal
QGP at a vanishing chemical potential. We find a significant effect for the GUP
term. The main features of QCD lattice results were quantitatively achieved in
case of , and flavors for the energy density,
the pressure and the interaction measure. The exciting point is the large value
of bag pressure especially in case of flavor which reflects the
strong correlation between quarks in this bag which is already expected. One
can notice that, the asymptotic behavior which is characterized by
Stephan-Boltzmann limit would be satisfied.Comment: 9 Pages, 8 figure
Modified dome shaped proximal tibial osteotomy for treatment of infantile tibia vara
Background: Tibial deformity in childhood is not always one plane deformity, but often combines torsional and angular malalignment.Methods: In this prospective study, dome shaped osteotomy was performed in 36 tibiae in 24 patients. The osteotomy was held with K-wires and a plaster cast. The mean age at surgery was 5.5 years and the mean follow-up time was 30 months, range (24-42) months.Results: All osteotomies united and no compartment syndrome occurred. Postoperatively, one leg (2.7%) had temporary weakness of external hallucis longus muscle. Thirty five of thirty six legs had good clinical and radiological correction of alignment. Recurrent deformity was seen in one leg. ‎ Conclusions: Dome shaped osteotomy of the tibia is a simple, safe and effective method for correction of uni-planar varus deformity. For bi-planar deformities in childhood with infantile tibia vara we may need to step cut the lateral cortex to allow good bone contact to help in union with minimum morbidity.
Static and Dynamic Studies of Gasoline in View of its Octane Number and its Toxic Effect
Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel
Physiological factors affecting the production of an antimicrobial substance by Streptomyces violatus in batch cultures
Egyptian Journal of Biology Vol.3 2001: 1-1
Effectiveness of Gamified Cooperation and Competition in Blended Learning Environment for EFL Business Writing in TVET
This research investigated the effectiveness of gamified blended learning environments in fostering EFL writing skills among technical and vocational education and training (TVET) trainees in Saudi Arabia. It compared three distinct learning strategies achieved through gamification design in a blended delivery mode: gamified cooperation, gamified competition, and gamified cooperation-competition. Each strategy leveraged a specific category of gamification features that evoke different goal structure: cooperation, competition, or a combination of both. A quasi-experimental design with a pre-test and post-test was employed. Forty-five trainees were purposively selected and randomly assigned to three groups, each receiving instruction using a different gamified blended learning program for teaching business writing. The findings revealed significant improvement in English as a Foreign Language business writing skills for all three groups. However, a one-way ANOVA and post-hoc Tukey HSD test indicated that the gamified cooperation-competition strategy yielded the greatest improvement compared to the gamified cooperation and gamified competition strategies alone. This suggests that a combination of cooperative and competitive elements within a gamified blended learning environment might be the most effective approach for enhancing English as a Foreign Language business writing skills among Technical and Vocational Training and Education learners
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