Finite element modeling of flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets

In this research, the finite element method is used to develop a numerical model to analyse the effect of the external strengthening of reinforced concrete beams by using carbon Fiber Reinforced Polymer (CFRP) sheets. A finite element model has been developed to investigate the behavior of RC beams strengthened with CFRP sheets by testing nineteen externally simple R.C. beams, tested under a four-point load setup until failure. Various CFRP systems were used to strengthen the specimens.  The numerical results using the (ANSYS workbench v.19.1) were calibrated and validated with the experimental results.  The research results indicate a significant improvement in the structural behavior of the specimens strengthened using CFRP sheet systems. Then the validated model investigated the effect of the width of CFRP sheets, no of layers, and CFRP size on the behavior of strengthened R.C. beams. Results of this numerical investigation show the effectiveness of increase CFRP width to improve the flexural capacity of R.C. beams. An increase in the flexural capacity up to 100 % compared to the control beam

Pre-service Teachers’ Perception of their Educational Preparation

Abstract: This study aimed at investigating pre-service teachers’ views of their educational preparation taking into consideration six study domains, namely: planning and preparation for instruction, classroom environment, professional responsibility, teaching skills, time allotted for learning different subjects, and time allotted for learning certain skills in the program. The differences among the six domains and pre-service teachers’ demographic information such as gender, pre-service teachers’ study majors, and the school level they were prepared to teach (Basic vs. Secondary) were investigated. Additionally, the study examined the extent to which the six study domains predicted the pre-service teachers’ teaching skills. Findings of the study revealed that pre-service teachers have positive views on their own pedagogical preparation. In responding to their perception pertinent to the six domains of this study, the majority of the pre-service teachers thought that they had been “highly prepared” or “well prepared”. However, there were no statistically significant differences in terms of the pre-service teachers’ gender and teaching majors. Other findings were discussed and the study gives some recommendations. Key word: Pre-service Teachers ‘views, Educational Preparation, Perception

Talar body fracture combined with medial malleolar fracture: a case report and literature review

Fracture of the talar body is rare, it reaches articular congruence and determines the ankle's functional prognosis. The authors report a case of a combination of a sagittal talar body fracture with fracture of the medial malleolus in a 52-year-old following a road traffic accident. The association talus body fracture with a medial malleolus fracture is exceptional. Stable internal fixation can yield good functional results

Effect of Silica Fume on Some Properties of No-Fine Concrete with Recycled Coarse Aggregate

No-fines Concrete is a lightweight porous concrete produced by omitting sand from the traditional concrete mix. It helps replenish the groundwater aquifer by directly allowing precipitation to seep into the earth thanks to its wide pores. This work studied the influence of partially replacing cement with silica fume (SF) with percentages of 5, 8, and 10% on some properties of no-fine concrete made using recycled coarse aggregate. The natural coarse aggregate (NA) was replaced with 10%, 20%, and 30% by crushed reactive powder concrete waste volume as recycled aggregate (RA). The optimum percentage was 10% RA with 10% SF, which indicated a substantial improvement in the no-fine concrete's strength, dry density, and water absorption compared to the design mix. The results exhibit increases in percentages in compressive strength, tensile strength, flexural strength, and dry density by 18%, 14%, 16%, and 1%, respectively, while exhibiting a decrease in water absorption by 5% at 28 days

Evaluation of empagliflozin efficacy as a promising anti-aging treatment in mice: In-vivo study

Aim: Evaluation of the anti-aging properties of Empagliflozin (EMP) associated with the aging process in mice. Methods: The mice were allocated into four groups: negative control received normal saline without receiving D-galactose (DGA); all the three other groups received DGA (200 mg/kg/day orally) for eight weeks; the second group received normal saline; the third group received vitamin C, the final group received EMP and continued for another eight weeks. Results: Treatment with EMP reduced the levels of TNF-α, IL-1β, and MDA levels significantly compared to induction group (91.7±9.6 ng/ml, 30.6±5.5 pg/ml, and 66.7±8.3 ng/ml vs. 304.0±102.9 ng/ml, 70.2±6.8 pg/ml, and 204.7±56.9 ng/ml; respectively), while levels of GSH-Px were significantly increased (3.3±0.6 ng/ml vs. 0.3±0.2 ng/ml). In addition, EMP increases the level of both COL-1 and COL-3 compared to the induction group (1,783.6±186.9, and 1,583.6±186.9, vs. 885.7±242.5, and 685.7±242.5 pg/ml; respectively). Conclusion: EMP positively affects several aging parameters in mice

Recovery modeling in MPLS networks

Transmission of QoS based traffic over packet switched network typically requires resource reservation or differentiated treatment to guarantee an acceptable level of performance. But it is also essential to bound the disruption caused by failure of nodes or links for a real time traffic to a limit that is acceptable by the application. In this paper, a simulation platform models the impact of the MPLS recovery/protection schemes on the QoS traffic parameters including disruption time and number of out of order packets arriving at the destination. The simulation considers measures to alleviate drawbacks caused by recovery process

Reliability evaluation of scalable complex networks through delta-star conversion

Exact reliability evaluation of large size complex networks becomes intractable with conventional techniques due to the exponential scaling of the computation complexity as the size of network scales up. In this paper we develop a scalable model for the exact evaluation of system reliability of scalable complex networks of the n-tuple bridge type based on scaled delta-star conversion. The number of steps as well as the computation overhead is kept within practical limits as they scale up linearly with the size of the network. The proposed model enables simple numerical evaluation either manually or through spread-sheets

Prediction of Compressive Strength of Reinforced Concrete Structural Elements by Using Combined Non-Destructive Tests

This research is devoted to investigate relationship between both Ultrasonic Pulse Velocity and Rebound Number (Hammer Test) with cube compressive strength and also to study the effect of steel reinforcement on these relationships. A study was carried out on 32 scale model reinforced concrete elements. Non destructive testing campaign (mainly ultrasonic and rebound hammer tests) made on the same elements. About 72 concrete cubes (15 X 15 X15) were taken from the concrete mixes to check the compressive strength.. Data analyzed.Include the possible correlations between non destructive testing (NDT) and compressive strength (DT) Statistical approach is used for this purpose. A new relationships obtained from correlations results is given

Availability analysis of terrestrial free space optical link under the impact of rain condition

Availability is one of the main factors to measure the QoS of any telecommunication networks. An accurate availability prediction for Free Space Optical link of carrier class grade is needed. In tropical areas, rain is the most dominant factor affecting the FSO link availability. In this paper, the effect of rain attenuation on the availability of FSO links is analyzed by examining the impact distance of different FSO systems. As the rain attenuation of FSO is independent of wavelength, the analysis of rain attenuation will be based on rain intensity. ITU-R (Carbonneau and Japan) models have been used for the analysis. From the results; Carrier class availability with good enough resolution for estimated availability can be predicted. This paper provides recommendations to FSO researchers in general and local telecom service provider in particular about possible availability figures that can be useful for deployment of FSO link as a last mile solution, back-up for fiber optic and other applications