Long-term deflection of high-strength fiber reinforced concrete beams

Ashour, Samir A.,Mahmood, Khalid,Wafa, Faisal F. Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.8 No.6

The paper presents an experimental and theoretical study on the influence of steel fibers and longitudinal tension and compression reinforcements on immediate and long-term deflections of high-strength concrete beams of 85 MPa (12,300 psi) compressive, strength. Test results of eighteen beams subjected to sustained load for 180 days show that the deflection behavior depends on the longitudinal tension and compression reinforcement ratios and fiber content; excessive amount of compression reinforcement and fibers may have an unfavorable effect on the long-term deflections. The beams having the ACI Code's minimum longitudinal tension reinforcement showed much higher time-dependent deflection to immediate deflection ratio, when compared with that of the beams having about 50 percent of the balanced tension reinforcement. The results of theoretical analysis of tested beams and those of a parametric study show that the influence of steel fibers in increasing the moment of inertia of cracked transformed sections is most pronounced in beams having small amount of longitudinal tension reinforcement.

Event-Based Ontologies: A Comparison Review

Ashour Ali,Shahrul Azman Mohd Noah,Lailatul Qadri Zakaria International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.5

Ontologies are knowledge containers in which information about a specified domain can be shared and reused. An event happens within a specific time and place and in which some actors engage and show specific action features. The fact is that several ontology models are based on events called Event-Based Models, where the event is an individual entity or concept connected with other entities to describe the underlying ontology because the event can be composed of spatiotemporal extents. However, current event-based ontologies are inadequate to bridge the gap between spatiotemporal extents and participants to describe a specific domain event. This paper reviews, describes, and compares the existing event-based ontologies. The paper compares and contrasts various ways of representing the events and how they have been modelled, constructed, and integrated with the ontologies. The primary criterion for comparison is based on the events' ability to represent spatial and temporal extent and the participants in the event.

The Effects of Injectable Platelet-Rich Fibrin and Advanced-Platelet Rich Fibrin on Gingival Fibroblast Cell Vitality, Proliferation, Differentiation

Ashour Sarraj H.,Mudalal Mahmoud,Al-Aroomi Omar A.,Al-Attab Reem,Li Wanxin,Yin Lihua 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7

BACKGROUND: Injectable Platelet Rich Fibrin (I-PRF) and Advanced-Platelet Rich Fibrin (A-PRF) are autologous materials derived from patients’ blood and employed in periodontal regenerative surgery. Although I-PRF and A-PRF have different characteristics, their biological effects on gingival tissue fibroblasts remain unclear. This research aims to compare the in vitro capacity in inducing gene expression and proliferation of human gingival fibroblasts between A-PRF and I-PRF. METHODS: Human donors undergoing dental implant surgery were sampled for normal human gingival fibroblasts (NHGFCs), followed by preparing A-PRF and I-PRF membranes. Enzyme-linked immunosorbent assay (ELISA) kit was used to assess the release of platelet-derived growth factor-AA (PDGF-AA), transforming growth factor-beta1 (TGF- b1), and insulin growth factor-1 (IGF-1) at different periods. Cell viability and proliferation of A-PRF and I-PRF were compared using CCK-8 assay. The impacts of platelet concentration on human gingival fibroblast cells (HGFCs) were evaluated by quantifying the level or amount of phosphorylated extracellular signal-regulated protein kinase (p-ERK), and Matrix metalloproteinases (MMPs), MMP-1 and MMP-3. The effects of PRF on aged human gingival fibroblast cells were examined retrospectively. RESULTS: Overall, A-PRF demonstrated a higher release of TGF-B1 and PDGF-AA, while I-PRF reflected higher levels of IGF-1. A significantly higher level of cell proliferation was induced by higher cell proliferation by A-PRF and I-PRF. Additionally, in comparison to I-PRF, the expression of ERK phosphorylation and MMP-1 &MMP-3 in HGFCs was demonstrated by I-PRF and A-PRF. The increase in A-PRF was time-dependent (p\0.05). CONCLUSION: Both I-PRF and A-PRF induced a stimulatory biological impact on the proliferation of human gingiva fibroblasts, with the latter demonstrating better capacity in facilitating the release of different growth factors. A-PRF also induced higher gene expression of p-ERK, MMP-1 &MMP-3, and the proliferation of fibroblasts.

Consumer Adoption of Self-Service Technologies: Integrating the Behavioral Perspective with the Technology Acceptance Model

ASHOUR, Mohammed L.,AL-QIREM, Raed M. Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

Recent technological advancements have had a substantial impact on consumer buying behavior. This research aims to determine the factors affecting consumer behavior related to the adoption of self-service technologies (SSTs). The intended findings of this study are expected to contribute to understanding consumer behavior towards the adoption of SSTs taking into account the logic of two main theories in this regard: the Technology Acceptance Model (TAM) and the assumptions of the Behavioral Perspective Model (BPM). This research follows a triangulation approach. Consequently, a number of semi structured interviews were conducted with experts and executive directors from selected SSTs providers in Jordan. In addition, the convenience sampling technique was employed focusing on current (or) previous users of SSTs in the public and private sectors in Jordan using a self-administrative questionnaire (66% response rate). The results confirmed the influence (direct and indirect) of previous experience and personal initiatives and characteristics on consumer intention to use SSTs. In addition, the results indicated the important role of the mediator variables namely: perceived ease of use (EOU), perceived risk (PR), and perceived usefulness (PU) on consumer attitude towards SSTs which in turn will positively affect consumer intention to use SSTs.

Removal of Pesticide (Endosulphan) from Water via Adsorption onto Activated Carbons Developed from Date Pits

Ashour, Sheikha.S. Korean Carbon Society 2007 Carbon Letters Vol.8 No.2

Activated carbons were prepared by impregnation of crushed clean date pits in concentrated solutions of phosphoric acid or zinc chloride followed by carbonization in absence of air at $600^{\circ}C$. Steam-activated carbon was prepared by gasifying $600^{\circ}C$-carbonization product at $950^{\circ}C$ to a burn-off = 50%. KOH- activated carbon was prepared by impregnating date pitscarbonization product obtained at $450^{\circ}C$ in concentrated KOH solution followed by carbonization at $840^{\circ}C$. Textural properties of these carbons were determined from nitrogen adsorption at $-196^{\circ}C$ and the chemistry of the carbon surface was investigated by determination and of the surface carbon-oxygen (C-O) groups using bases of variable strength and dilute HCl. The adsorption of endosulphan at $27^{\circ}C$ on all the carbons prepared was undertaken. Adsorption of this pesticide at 32 and $37^{\circ}C$ was also undertaken for steam-activated and KOH-activated carbons. Phosphoric acid-activated carbons and steamactivated carbons are mainly microporous and have high surface concentration of C-O groups of acidic nature. Steamactivated and KOH-activated carbons exhibited surface areas > 1000 $m^2/g$ and contain micro and non-micrpores. The adsorption of endosulphan was related to the surface area of non-micropores and was retarded by the high concentration of surface C-O groups. The thermodynamic properties indicated the feasibility of the adsorption process and the possible regeneration of the carbon for further use.

Delay-Margin based Traffic Engineering for MPLS-DiffServ Networks

Ashour, Mohamed,Le-Ngoc, Tho The Korea Institute of Information and Commucation 2008 Journal of communications and networks Vol.10 No.3

This paper presents a delay-margin based traffic engineering (TE) approach to provide end-to-end quality of service (QoS) in multi-protocol label switching (MPLS) networks using differentiated services (DiffServ) at the link level. The TE, including delay, class, and route assignments, is formulated as a nonlinear optimization problem reflecting the inter-class and inter-link dependency introduced by DiffServ and end-to-end QoS requirements. Three algorithms are used to provide a solution to the problem: The first two, centralized offline route configuration and link-class delay assignment, operate in the convex areas of the feasible region to consecutively reduce the objective function using a per-link per-class decomposition of the objective function gradient. The third one is a heuristic that promotes/demotes connections at different links in order to deal with concave areas that may be produced by a trunk route usage of more than one class on a given link. Approximations of the three algorithms suitable for on-line distributed TE operation are also derived. Simulation is used to show that proposed approach can increase the number of users while maintaining end-to-end QoS requirements.

Investigating medical students’ satisfaction towards video-based learning versus face-to-face lectures: a Jordanian tertiary teaching hospital experience

Omar Ashour,Ahmad Muneer Alkhatib,Qusai Al Zureikat,Mustafa Al-Shaikhli,Basel Bani Ata,Talal Massad,Leen Al-Huneidy,Mohammed Qussay Al-Sabbagh,Abdallah Al-Ani 한국의학교육학회 2023 Korean journal of medical education Vol.35 No.1

Purpose: We aimed to evaluate the disparity between video-based learning and lecture-based learning on Jordanian medical students’ satisfaction. Methods: We conducted this cross-sectional study using a web-based questionnaire adapted from Student Evaluation of Educational Quality survey. Using convenience sampling, medical students studying at the University of Jordan and Jordan University Hospital were recruited. Participants in either clinical or basic-science years that have completed the entire survey were included in the final analysis. Results: We surveyed a total 487 participants among which male to female ratio was 1.19:1. Participants perceived greater benefit in terms of learning, instructor enthusiasm, content organization, breadth of teaching, and quality and number of assignments when using video-based learning (all p<0.01). In contrast, face-to-face learning was associated with significantly higher benefits in terms of group interactions (p<0.01) and capacity for rapport building (p<0.01). There was no significant difference in perceived examination performance between the two learning modalities (p=0.11). Conclusion: Video-based learning is the preferred learning modality among Jordanian medical students. Despite its dominance across multiple domains, it should be implemented as an adjunct to traditional classroom teaching for it is vital in the development of good communication skills and building rapport in medical students.

Representation of Event-Based Ontology Models: A Comparative Study

Ali, Ashour,Noah, Shahrul Azman Mohd,Zakaria, Lailatul Qadri International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.7

Ontologies are knowledge containers in which information about a specified domain can be shared and reused. An event happens within a specific time and place and in which some actors engage and show specific action features. The fact is that several ontology models are based on events called Event-Based Models, where the event is an individual entity or concept connected with other entities to describe the underlying ontology because the event can be composed of spatiotemporal extents. However, current event-based ontologies are inadequate to bridge the gap between spatiotemporal extents and participants to describe a specific domain event. This paper reviews, describes and compares the existing event-based ontologies. The paper compares various ways of representing the events and how they have been modelled, constructed, and integrated with the ontologies. The primary criterion for comparison is based on the events' ability to represent spatial and temporal extent and the participants in the event.

Delay-Margin based Traffic Engineering for MPLS-DiffServ Networks

Mohamed Ashour,Tho Le-Ngoc 한국통신학회 2008 Journal of communications and networks Vol.10 No.3

This paper presents a delay-margin based traffic engineering (TE) approach to provide end-to-end quality of service (QoS) inmulti-protocol label switching (MPLS) networks using differentiated services (DiffServ) at the link level. The TE, including delay, class, and route assignments, is formulated as a nonlinear optimization problem reflecting the inter-class and inter-link dependency introduced by DiffServ and end-to-end QoS requirements. Three algorithms are used to provide a solution to the problem: The first two, centralized offline route configuration and link-class delay assignment, operate in the convex areas of the feasible region to consecutively reduce the objective function using a per-link perclass decomposition of the objective function gradient. The third one is a heuristic that promotes/demotes connections at different links in order to deal with concave areas that may be produced by a trunk route usage of more than one class on a given link. Approximations of the three algorithms suitable for on-line distributed TE operation are also derived. Simulation is used to show that proposed approach can increase the number of users while maintaining end-to-end QoS requirements.

Buckling and vibration of symmetric laminated composite plates with edges elastically restrained

Ahmed S. Ashour 국제구조공학회 2003 Steel and Composite Structures, An International J Vol.3 No.6

The finite strip transition matrix technique, a semi analytical method, is employed to obtain the buckling loads and the natural frequencies of symmetric cross-ply laminated composite plates with edges elastically restrained against both translation and rotation. To illustrate the accuracy and the validation of the method several example of cross play laminated composite plates were analyzed. The buckling loads and the frequency parameters are presented and compared with available results in the literature. The convergence study and the excellent agreement with known results show the reliability of the purposed technique.