Ahmed M. Ellakany, Mohamad Ali, Mohamed A. El-Gohary and Mohamed Elkholy
The purpose of this paper is to introduce a numerical model to investigate static response of elastic steel-concrete beams. The numerical model is based on the lumped system with…
Abstract
Purpose
The purpose of this paper is to introduce a numerical model to investigate static response of elastic steel-concrete beams. The numerical model is based on the lumped system with the combination of the transfer matrix and the analog beam methods (ABM). The beams are composed of an upper concrete slab and a lower steel beam, connected at the interface by shear transmitting studs. This type of beam is widely used in constructions especially for highway bridges. The static field and point transfer matrices for the element of the elastic composite beam are derived. The present model is verified and is applied to study the static response of elastic composite beams with intermediate conditions. The intermediate condition is considered as an elastic support with various values of stiffness. The elastic support can be considered rigid when the stiffness has very high values. The influence effect of shear stiffness between the upper slab and lower beam, and the end shear restraint on the static behavior of the composite beams is studied. In addition, the change in the stiffness of the elastic support is also highlighted.
Design/methodology/approach
The objective of this study is to introduce a numerical model based on lumped system to calculate the static performance of elastic composite bridge beams having intermediate elastic support by combining the ABM with the transfer matrix method (TMM). The developed model is applicable for studying static and dynamic responses of steel-concrete elastic composite beams with different end conditions taking into account the effect of partial shear interactions. The validity of the lumped mass model is checked by comparing its results with a distributed model and good agreements are achieved (Ellakany and Tablia, 2010).
Findings
A model based on the lumped system of the elastic composite steel-concrete bridge beam with intermediate elastic support under static load is presented. The model takes into consideration the effect of the end shear restraint together with the interaction between the upper slab and the lower beam. Combining the analogical beam method with the TMM and analyzing the behavior of the elastic composite beam in terms of shear studs and stiffness, the following outcomes can be drawn: end shear restraint and stiffness of the shear layer are the two main factors affecting the response of elastic composite beams in terms of both the deflection and the moments. Using end shear restraint reduces the deflection extensively by about 40 percent compared to if it is not used assuming that: there is no interaction between the upper slab and the lower beam and the beam is acting as simply supported. As long as the shear layer stiffness increases or interaction exists, the deflection decreases. This reduced rate in deflection is smaller in case of existence of end shear restraint. The effect of the end shear restraint is more prevailing on reducing the deflections in case of partial interactions. However, its effect completely diminishes in case of complete interaction. Presence of the end shear restraint and shear layer stiffness produces almost the same variations in the components of the bending moments of the composite beam. Finally, for a complete interaction, comparing the case of using end shear restraint or the case without it, the differences in the values of the deflections and moments are almost negligible.
Research limitations/implications
The following assumptions related to the theory of ABM: shear studs connecting both sub-beams are modeled as a thin shear layer, each sub-beam has the same vertical displacement and the shear deformation in the sub-beams is neglected.
Practical implications
The developed model can be effectively used for a quick estimation of the dynamic responses of elastic composite beams in real life rather than utilizing complicated numerical models.
Social implications
The applications of this model can be further extended for studying the behavior of complex bridge beams that will guarantee the safety of the public in a quick view.
Originality/value
Previous models combined the TMM with the ABM for studying the static and free-vibration behaviors of elastic composite beams assuming that the field element is subjected to a distributed load. To study the dynamic response of elastic composite beams subjected to different moving loads using transfer matrix ABM, it was essential to use a massless field element and concentrate the own weight of the beam at the point element. This model is considered a first step for studying the impact factors of elastic composite beams subjected to moving loads.
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H.Z. Shams, M.H. Helal, F.A. Mohamed and S.A. Abd‐Elhafiz
A new series of the title pyrazole azo dye systems has been synthesized. The new dyes are applied on nylon and cellulose acetate fibers to give dyed fabrics with excellent…
Abstract
A new series of the title pyrazole azo dye systems has been synthesized. The new dyes are applied on nylon and cellulose acetate fibers to give dyed fabrics with excellent properties of colour intensity and fastness properties. The physical and spectral data of the investigated dyes are illustrated. The shifts of ultraviolet‐visible absorption maxima affected by the structural configuration of the pyrazole dye systems are investigated. The structural effects of the polyfunctionally substituted pyrazole dye systems on the intensity of colour and fastness properties of the dyed fabrics are discussed. The data of these studies are listed. The colour shades of the synthesized dyes on nylon and acetate fabrics are indicated.
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Wen Zhan, Shengpeng Zhan, HaiTao Duan, Xinxiang Li, Jian Li, Bingxue Cheng and Chengqing Yuan
This paper aims to study the thermal oxidation performance of antioxidant additives in ester base oils deeply.
Abstract
Purpose
This paper aims to study the thermal oxidation performance of antioxidant additives in ester base oils deeply.
Design/methodology/approach
ReaxFF molecular dynamics was used to simulate the thermal oxidation process of butyl octyl diphenylamine and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate as two antioxidant additives act on the Trimethylolpropane trioleate (TMPTO) base oil. Meanwhile, combining with the infrared spectroscopy characterization results of the thermal oxidation test, this paper provides theoretical support for the development of high-performance synthetic lubricants and their antioxidant additives.
Findings
The results show that butyl octyldiphenylamine easily removes the hydrogen atom on the secondary amine, which promotes the formation of more long carbon chain diene radicals or polyene hydroperoxides from TMPTO. Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate could easily decompose into octadecyl hydroperoxide and 2,6-di-tert-butyl 4-propionylphenol, which could convert into 2-tert-butyl-4-peroxyethyl-6-hydroperoxy-tert-butylphenol in the middle of the thermal oxidation reaction, prompting TMPTO to form more short-chain alkenyl and olefin hydroperoxide or other oxide.
Originality/value
The main change characteristics of base oil molecules are the first thermal decomposition to form oleic acid groups and ethane cyclopropane methyl oleate. Under the action of butyl octyldiphenylamine and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate, the deep oxidation and decomposition reaction are slowed down.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0037/
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H.Z. Shams, M.H. Helal and F.A. Mohamed
Three series of azo dye systems are considered, namely, 5‐oxo‐2‐pyrazoline azo dye systems 9 a‐d,1‐oxo‐pyrazolo pyrazole azo dye systems 10 a, b, c, e, 11 a, b, c, e, 12 a, b, c…
Abstract
Three series of azo dye systems are considered, namely, 5‐oxo‐2‐pyrazoline azo dye systems 9 a‐d,1‐oxo‐pyrazolo pyrazole azo dye systems 10 a, b, c, e, 11 a, b, c, e, 12 a, b, c, e, 13 a‐d and 6‐oxo‐pyranopyrzole azo dye systems 14 a‐d. The shifts of ultraviolet‐visible absorption maxima affected by the structural configuration of the pyrazole dye systems are investigated. The structural effects of the polyfunctionally substituted pyrazole dye systems on the intensity of colour and fastness properties of the dyed fabrics are also discussed. The data of these studies are listed. Colour shades of the synthesized dyes on nylon and acetate fabrics are indicated.
This paper aims to synthesise some novel diazobenzene dyestuffs clubbed with sulphonamide moiety and their application for polyester fabrics in addition to evaluating their…
Abstract
Purpose
This paper aims to synthesise some novel diazobenzene dyestuffs clubbed with sulphonamide moiety and their application for polyester fabrics in addition to evaluating their biological activities.
Design/methodology/approach
New diazobenzene disperse dyes with improved chemical construction via sulphonamides were designed. This amendment of diazobenzene dyes was completed by introducing sulphonamide derivatives through Japp–kilingman reaction. All new synthesised dyes were elucidated by elemental analyses and spectral data (IR and 1 H-NMR). Biological activities of the synthesised diazobenzene sulphonamide derivatives were evaluated.
Findings
The synthesised diazobenzene dyestuffs clubbed with sulphonamides were applied on polyester fabrics. The synthesised dyes showed that good fastness properties and their biological evaluation exhibited good efficacy towards antibacterial, antioxidant and anticancer.
Originality/value
Sulphonamide derivatives have numerous uses, such as being used in dyestuff and providing antimicrobial, antioxidant, and anticancer properties. Sulphonamide derivatives with diazobenzene coupler components exhibited an interesting colorant for polyester and provided better biological efficacy for other non-textile applications. This work afforded new disperse dyes beside their medical applications.
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Khalid Rabaeh, Ahmed A. Basfar and Issra’ M.E. Hammoudeh
This study aims to develop a film dosimeter composed of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MMT) dye and polyvinyl butyral (PVB) binder to reduce the…
Abstract
Purpose
This study aims to develop a film dosimeter composed of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MMT) dye and polyvinyl butyral (PVB) binder to reduce the effect if relative humidity effect during irradiation.
Design/methodology/approach
The films were exposed to gamma ray radiation from a 60Co gamma ray source with 8.6 kGy/h dose-rate and 1.25 MeV beam energy to various doses ranging from 2.5 to 100 kGy. UV-VIS spectrophotometer was used to measure the changes in optical properties of irradiated films by means of the changes in the absorbance values at wavelength of 560 nm.
Findings
The effect of irradiation temperature, relative humidity, fluorescent light and postirradiation stability on the performance of developed film dosimeter were investigated.
Practical implications
Previous MMT dye with PVA binder was significant effect of the relative humidity on the dose response of MMT-PVA films which decrease the practical feasibility of using these films in routine high-dose measurements. Therefore, the purpose of this study is to reduce the relative humidity effect on the dose response by proposing a formula for film dosimeters that combines MMT dye with the polyvinyl butyral (PVB) binder.
Originality/value
The irradiation of MMT-PVB films leads to a change in color from yellow to brown, which could be evaluated by the absorbance intensity.
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Ebtsam Abdelmowla Ahmed, Galal Elgemeie and Kawther Abd-Elzaher Ahmed
This study aims to represent a successful simple method for the synthesis of some novel dyes based on thiazole derivatives and their applications in textile printing.
Abstract
Purpose
This study aims to represent a successful simple method for the synthesis of some novel dyes based on thiazole derivatives and their applications in textile printing.
Design/methodology/approach
2-(benzo[d]thiazol-2-ylmethyl)thiazol-4(5H)-one compound is prepared by convention heating and microwave technique then used as a coupling agent, which reacts with different diazonium Salt to form diazo dyes.
Findings
The synthesized diazo dyes are confirmed via spectral data (IR,1H-NMR, 13C-NMR and Mass spectra). The dyes are used to print polyester fabric. The obtained results clarified that the prints have good color strength, brilliant color and highly durable antibacterial activity.
Originality/value
The authors designed efficient synthesis for some novel thiazolone dyes. The novel procedure features short-reaction time, very good yields and a simple workup. The authors studied the antibacterial activity and their application in printing polyester fabrics.
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This paper gives a review of the finite element techniques (FE) applied in the analysis and design of machine elements; bolts and screws, belts and chains, springs and dampers…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the analysis and design of machine elements; bolts and screws, belts and chains, springs and dampers, brakes, gears, bearings, gaskets and seals are handled. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of this paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An Appendix included at the end of the paper presents a bibliography on finite element applications in the analysis/design of machine elements for 1977‐1997.
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Gives a bibliographical review of the finite element meshing and remeshing from the theoretical as well as practical points of view. Topics such as adaptive techniques for meshing…
Abstract
Gives a bibliographical review of the finite element meshing and remeshing from the theoretical as well as practical points of view. Topics such as adaptive techniques for meshing and remeshing, parallel processing in the finite element modelling, etc. are also included. The bibliography at the end of this paper contains 1,727 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1990 and 2001.