Ductile corrosion-free self-centering concrete elements

Corrosion is a major factor in the deterioration of reinforced concrete (RC) structures. To mitigate this problem, steel bars can be replaced with glass-fiber-reinforced-polymer (GFRP) bars. However, the lack of ductility of GFRP-RC elements has prevented their use in many structural applications, especially in seismic areas. Superelastic shape memory alloy (SMA) bars have been proposed to be used in seismic areas because of their self-centering characteristics. Also, they have the added advantage of being corrosion resistant. This paper examines the combined use of SMA and GFRP bars to achieve ductile self-centering and corrosion-free elements. The first challenge for such a proposal relates to designing concrete frames, reinforced with SMA and GFRP bars, that have adequate lateral performance in terms of initial stiffness, ductility, and strength. A comprehensive parametric study is conducted to better understand the structural behavior of concrete elements reinforced with SMA and/or GFRP bars. Results from the study are utilized to develop design equations that allow designing an SMA/GFRP RC section to replace a steel RC section, while maintaining lateral strength, stiffness, and ductility. To examine the adequacy of the developed equations, a six-storey concrete frame is designed, and its lateral performance is examined using pushover analysis

Ductile Corrosion-Free GFRP-Stainless Steel Reinforced Concrete Elements

Corrosion of steel rebars is known to cause deterioration of concrete structures that can lead to catastrophic failures. To mitigate this problem, steel rebars can be replaced with Glass Fiber-Reinforced Polymer (GFRP) rebars. However, the lack of ductility of GFRP-reinforced elements has prevented their use in many structural applications, especially in seismic areas. Stainless Steel (SS) rebars are corrosion resistant and have adequate energy absorption and ductility. However, they are much more expensive than steel rebars. This paper proposes the combined use of SS and GFRP rebars to achieve ductile and corrosion-free elements. The first challenge for such a proposal relates to designing SS-GFRP reinforced concrete frame with adequate lateral performance in terms of initial stiffness, ductility, and strength. Design equations, which are based on a comprehensive parametric study, are developed to allow designing such a frame. A six-storey concrete frame is then designed using the proposed equations and its lateral performance is examined using pushover analysis

Impact of Tactile Stimulation on Neurobehavioral Development of Premature Infants in Assiut City

Objective: To assess impact of tactile stimulation on neurobehavioral development of premature infants in Assiut City. Design: Quasi-experimental research design. Setting: The study was conducted in the Neonatal Intensive Care Unit at Assiut University Children Hospital, Assiut General Hospital, Health Insurance Hospital (El-Mabarah Hospital) and El-Eyman for Gynecology and Obstetric Hospital. Subjects: The study subjects included a convenient sample of 50 premature infants divided into study or control groups and they were matched with gestational age and birth weight. Tool: Brazelton Neonatal Behavioral Assessment Scale is used to assess neurobehavioral development of infants from birth to two months of age. Method: Premature infants divided into two groups; (a) study group who receiving tactile stimulation (b) control group who receiving routine hospital care only. Neurobehavioral development using Brazelton’s Neonatal Behavior Assessment Scale (NBAS) was assessed at initial contact and after 5 days of intervention and on discharge. Results: showed that the premature infants of the study had better neurobehavioral development than those in the control group with statistical significant differences were found between the study and the control groups Conclusion: It was concluded from the findings of the current study that premature infants who received tactile stimulation had better neurobehavioral development than those who didn’t receive it and had only the hospital routine care. Keywords: Tactile stimulation, neurobehavioral development, premature infant

Hydrodynamics of Pilot-Scale Bubble Columns: Effect of Internals

The Gas Holdup and Bubble Characteristics Are Key Parameters that Affect the Performance of Bubble Columns. an Experimental Study of the Effect of Heat Exchanging Internals on the Gas Holdup, Bubble Dynamics, and their Radial Profiles is Performed. an Air-Water System is Used in a Plexiglas Column 45 Cm (18 In.) in Diameter. Internals Configurations Mimicking Those Typical for the Liquid-Phase Methanol Synthesis and Fischer-Tropsch Process and Covering 5% and 25%, Respectively, of the Total Cross-Sectional Area of the Column, Are Investigated. High Superficial Gas Velocities that Fall within the Churn Turbulent Flow Regime, Which Are of Interest for Most Industrial Applications, Are Applied. an Increase in the Gas Holdup is Observed for the Dense Internals Structure. a Decrease in the Bubble Chord Length and a Vigorous Recirculation Behavior Are Also Obtained as a Result of the Insertion of the Internals. © 2012 American Chemical Society

The Egyptian, Iranian, Iraqi and Ukrainian students occlusion dependence on dominant extremity and gender

According to our results received the real dexters had only orthognathic and prognathic occlusions. Orthogenic occlusion was dominant in the real sinisters. The hidden sinisters did not have any physiological occlusion types but had biprognathic and deep occlusion in the equal correlation. The unreal sinisters had orthognathic, prognathic and biprognathic occlusions. The ambidexters did not have occlusion physiological types but had a practically equal distribution in opisthognathic and crossing occlusion. Orthognathic occlusion was dominant in the Egyptian, Iranian and Iraqi students while deep occlusion - in the Ukrainian ones. Deep and orthog nathic occlusion were dominant in the guys and the progenic one was absent in them. Biprognathic occlusion was insignificantly dominant in the girls while the orthog nathic and the deep ones were absent in them

1-Benzyl-3-methyl­quinoxalin-2(1H)-one

The asymmetric unit of the title compound, C16H14N2O, contains three independent mol­ecules. The dihedral angles between the quinoxaline and phenyl planes in the three mol­ecules are 82.58 (8), 85.66 (9) and 85.36 (9)°. The crystal packing is stabilized by C—H⋯O and C—H⋯N hydrogen bonds

Human typological aspects and maxillary-facial area asymmetry connections to mandibular fractures in HSEEU «UMCA» ukrainian students

Asymmetry is maxillary-facial region feature which is expressed both under physiological and pathological conditions. Some literary data of Turkish dentists show higher level (approximately in 2 times and the difference is statistically significant) of traumatized permanent incisors among left-handers (13-17-yeared adolescents) than among right-handers. Left-handers had significantly higher risk on dental trauma. Unilateral clefts affinity has been confirmed for the left side, the proportion of left-sided clefts among left-handers are higher than that among right-handers. Another scientific work demonstrates handedness influence on ethmoid roof height

Synthesis and antimicrobial study of new tetrazole, benzimidazole and N3-functionalized quinazolinone derivatives

Reactions of 4H-3,1-benzoxazin-4-one 3 with various nitrogen nucleophiles; sodium azide, hydroxylamine hydrochloride, ammonium acetate, and formamide afforded new N-heterocyclic compounds 4-7. The synthesized quinazolinone derivative 7 was used as a useful building block for further synthesis of new series of N3-functionalized quinazolinone compounds 8-12. The chemical structures of all synthesized heterocyclic compounds were deduced from their spectroscopic analyses. The antimicrobial activity of the new compounds was evaluated against several pathogenic microorganisms, and most of them showed remarkable activity comparable to the antibacterial Ciprofloxacin and antifungal Clotrimazole

Laying performance, digestibility and plasma hormones in laying hens exposed to chronic heat stress as affected by betaine, vitamin C, and/or vitamin E supplementation

Heat stress had a negative effect on laying hens' performance, thus this research was to study the influences of betaine (Bet, 1000 mg/kg betaine), vitamin C (VC, 200 mg/kg ascorbic acid), and vitamin E (VE, 150 mg/kg a-Tocopherol acetate) and their possible combinations on egg production, digestibility of nutrients, plasma hormones and reproductive organs of dual-purpose hens exposed to chronic heat stress. Two hundred and eighty eight hens and thirty-six cocks from 32 to 48 weeks of age were divided into nine treatment groups of four replicates, each containing eight hens and one cock. One group was kept under thermo-natural condition and the eight others were kept under chronic heat stress (CHS). One of these eight was used as a negative control, while the others were supplemented with VC, VE and/or betaine and their possible combinations. Body weights, laying rate, feed intake, and feed conversion ratio in hens reared under CHS rooster without any supplementation during 32 to 48 weeks of impairment (P = 0.0052) were recorded. Hens reared under heat stress and fed a diet supplemented with either Bet, VC, VE or combination of the supplements increased production traits. However, hens supplemented with VC showed the greatest production traits. Plasma glucose, estradiol-17 (E-2), progesterone (P-4), tri-iodothyronine (T-3) and thyroxine (T-4) decreased in hens reared under CHS and fed a diet with no supplementation compared to the other treatments (P = 0.001). Liver weights, spleen weights, thyroid gland weights, ovary weights, oviduct weights and oviduct lengths were lowest in hens reared under CHS and fed a diet with no supplementation (P = 0.0480). In conclusion, dual purpose hens reared under CHS and supplemented with VC at 200 mg/kg diet and Bet at 1000 mg/kg enhanced the laying performance and combated CHS