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Article
Publication date: 16 August 2019

Ahmed Mobasher, Alaa Khalil, Medhat Khashaba and Tarek Osman

The purpose of this paper is to evaluate the influence of nanoparticles as an additive on the tribological properties of calcium grease.

Abstract

Purpose

The purpose of this paper is to evaluate the influence of nanoparticles as an additive on the tribological properties of calcium grease.

Design/methodology/approach

The nano additives in this research are with different concentration of multi carbon nanotubes (MWCNTs) and Talc powder (1, 2, 3, 3 and 5 per cent). The ratio of MWCNTs to Talc powder is 1:1. The tribological properties of hyper MWCNTs/Talc powder to calcium grease were evaluated using a pin-on-disk wear testing. The results show that the nano additives MWCNTs/Talc to calcium grease exhibit good performance in anti-wear and friction reduction. The action mechanism was estimated through analysis of the worm surface with x-ray diffraction and transmission electron microscope.

Findings

The result indicates that boundary film mainly composed of MWCNT and Talc powder, and other organic compound was formed on the worm surface during the friction test. In addition, the wear rate and coefficient of friction of nanogreases have shown excellent improvement about 80.62 and 63.44 per cent, respectively, at 4 Wt.% of MWCNTs/Talc powder. Moreover, the thermal conductivity of nanogrease increased about 51.72 per cent.

Originality/value

This study describes the inexpensive and simple fabrication of nanogrease for improving properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 26 January 2021

Muhammad Shujaat Mubarik, Nick Bontis, Mobasher Mubarik and Tarique Mahmood

The main objective of this study is to test whether firms with a higher level of intellectual capital (IC) perform better in terms of their supply chain resilience…

Abstract

Purpose

The main objective of this study is to test whether firms with a higher level of intellectual capital (IC) perform better in terms of their supply chain resilience compared to those with lower levels of IC. Likewise, the study also examines the impact of IC (characterized by human capital, relational capital and structural capital) on supply chain resilience directly and through supply chain learning.

Design/methodology/approach

Data were collected from the 159 processed-food sector firms using a close-ended questionnaire during the corona virus 2019 (COVID-19) pandemic. Partial least squares structural equation modelling (PLS-SEM), partial least squares multigroup analysis (PLS-MGA) and one-way analysis of variance (ANOVA) were used to test a set of hypotheses emanating from a conceptual model of IC and supply chain resilience.

Findings

Empirical results revealed a significant influence of all dimension of IC on a firm's supply chain learning and supply chain resilience. Likewise, findings also exhibit a momentous role of supply chain learning in reinforcing the impact of IC on supply chain resilience. Cross-firm size comparison reveals that supply chain resilience of firms with a higher level of IC performed significantly better than those with lower levels of IC. Firms with a higher level of structural capital had a highly resilient supply chain.

Practical implications

Findings of the study imply that IC and supply chain learning should be considered as a strategic tool and should be strategically developed for uplifting a supply chain performance of a firm. The development of IC and supply chain learning (SCL) not only improves the supply chain resilience of a firm but also can help to integrate the internal and external knowledge for harnessing supply chain resilience.

Originality/value

This research study was conducted during the COVID-19 pandemic which provides a unique setting to examine resiliency and learning.

Details

Journal of Intellectual Capital, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1469-1930

Keywords

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Article
Publication date: 30 July 2019

Ahmed K. Abdelmoety, Taha H.A. Naga and Youssef F. Rashed

This paper aims to develop a new isogeometric boundary element formulation based on non-uniform rational basis splines (NURBS) curves for solving Reissner’s…

Abstract

Purpose

This paper aims to develop a new isogeometric boundary element formulation based on non-uniform rational basis splines (NURBS) curves for solving Reissner’s shear-deformable plates.

Design/methodology/approach

The generalized displacements and tractions along the problem boundary are approximated as NURBS curves having the same rational B-spline basis functions used to describe the geometrical boundary of the problem. The source points positions are determined over the problem boundary by the well-known Greville abscissae definition. The singular integrals are accurately evaluated using the singularity subtraction technique.

Findings

Numerical examples are solved to demonstrate the validity and the accuracy of the developed formulation.

Originality/value

This formulation is considered to preserve the exact geometry of the problem and to reduce or cancel mesh generation time by using NURBS curves employed in computer aided designs as a tool for isogeometric analysis. The present formulation extends such curves to be implemented as a stress analysis tool.

Details

Engineering Computations, vol. 37 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 May 2019

Jenarthanan M.P., Karthikeyan Marappan and Giridharan R.

The need for seeking alternate materials with increased performance in the field of composites revived this research, to prepare and evaluate the mechanical properties of…

Abstract

Purpose

The need for seeking alternate materials with increased performance in the field of composites revived this research, to prepare and evaluate the mechanical properties of e-glass and aloe vera fiber-reinforced with polyester and epoxy resin matrices.

Design/methodology/approach

The composites are prepared by hand layup method using E-glass and aloe vera fibers with length 5-6 mm. The resin used in the preparation of composites was epoxy and polyester. Fiber-reinforced composites were synthesized at 18:82 fiber–resin weight percentages. Samples prepared were tested to evaluate its mechanical and physical properties, such as tensile strength, flexural strength, impact strength, hardness and scanning electron microscope (SEM).

Findings

SEM analysis revealed the morphological features. E-glass fiber-reinforced epoxy composite exhibited better mechanical properties than other composite samples. The cross-linking density of monomers of the epoxy resin and addition of the short chopped E-glass fibers enhanced the properties of E-glass epoxy fiber-reinforced composite.

Originality/value

This research work enlists the properties of e-glass and aloe vera fiber-reinforced with polyester and epoxy resin matrices which has not been attempted so far.

Details

Pigment & Resin Technology, vol. 48 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 17 April 2007

Núria Ferran, Jaume Casadesús, Monika Krakowska and Julià Minguillón

The purpose of this research is to propose an evaluation framework for analyzing learning objects usage, with the aim of extracting useful information for improving the…

Abstract

Purpose

The purpose of this research is to propose an evaluation framework for analyzing learning objects usage, with the aim of extracting useful information for improving the quality of the metadata used to describe the learning objects, but also for personalization purposes, including user models and adaptive itineraries.

Design/methodology/approach

The paper presents experimental results from the log usage analysis during one academic semester of two different subjects, 350 students. The experiment examines raw server log data generated from the interactions of the students with the classroom learning objects, in order to find relevant information that can be used to improve the metadata used for describing both the learning objects and the learning process.

Findings

Preliminary studies have been carried out in order to obtain an initial picture of the interactions between learners and the virtual campus, including both services and resources usage. These studies try to establish relationships between user profiles and their information and navigational behavior in the virtual campus, with the aim of promoting personalization and improving the understanding of what learning in virtual environments means.

Research limitations/implications

During the formal learning process, students use learning resources from the virtual classroom provided by the academic library, but they also seek information outside the virtual campus. All these usage data are not considered in the model proposed here. Further research is needed in order to obtain a complete view of the seeking information behavior of students for improving the users' profile and creating better personalized services.

Practical implications

This paper suggests how a selection of fields used in the LOM standard could be used for enriching the description of learning objects, automatically in some cases, from the learning objects usage performed by an academic community.

Originality/value

From libraries beginnings, they have been a “quiet storage place”. With the development of digital libraries, they become a meeting place where explicit and implicit recommendations about information sources can be shared among users. Social and learning process interactions, therefore, can be considered another knowledge source.

Details

The Electronic Library, vol. 25 no. 2
Type: Research Article
ISSN: 0264-0473

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Article
Publication date: 13 May 2020

Essam Mossalam, Nivin M. Ahmed, Eglal M.R. Souaya and Basil El-Sabbagh

The purpose of this research is to study the physical and mechanical properties beside the durability of concrete as well as corrosion resistance of reinforced concrete by…

Abstract

Purpose

The purpose of this research is to study the physical and mechanical properties beside the durability of concrete as well as corrosion resistance of reinforced concrete by replacing Ordinary Portland cement (OPC) with different ratios of silica fume and meta-kaolin and applying two paint formulations to enhance corrosion resistance and mechanical properties. In this work, modified concrete mixes containing pozzolanic materials of industrial wastes such as silica fume (SF) with ratios ranging between (0, 10 and 15%) and calcined raw material such as meta-kaolin (MK) with ratios (0, 3, 5 and 10%), were introduced using water binder ratio (w/b) 0.45 to study their effect on the physico-mechanical properties and durability of concrete as well as corrosion protection performance of reinforced concrete. Two paint formulations containing the same ingredients except that one of them is free from talc (G1) and the other contains talc (G2) were applied on the rebars embedded in these modified mixes. Talc is known to offer high pH to the surrounding media.

Design/methodology/approach

Modified concrete mixes containing the coated reinforced concrete steel with the different paint formulations in presence and absence of talc were tested, and the corrosion behavior was studied using electrochemical impedance spectroscopy (EIS) in 3.5% NaCl, and the concrete mixes were also tested through their compressive strength, chloride permeability, scanning electron microscope/energy dispersive X-ray analysis and bond strength.

Findings

The results revealed that the hardened reinforced concrete mix containing 10% SF with 5% MK with embedded rebars coated with G2 (paint containing talc) was the best concrete system which offers concrete sustainability besides high corrosion protection performance, i.e. presence of talc in the paints combined with the effect of cement blended with SF and MK showed positive effect on the reinforced concrete properties that leads to more durability and workability.

Originality/value

The integrity of using two efficient methods of corrosion protection beside the effect of the different replacements in concrete mixes containing coated reinforced concrete steel with paint formulations free from talc (G1) and others containing talc (G2), which lead to fatal changes in the pH of the surrounding media (i.e. concrete which has high alkaline pH) to achieve good concrete properties aside with convenient paint formulations together.

Details

Pigment & Resin Technology, vol. 50 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 7 September 2020

Kiran Mansingrao Mane, D.K. Kulkarni and K.B. Prakash

The use of huge quantity of natural fine aggregate (NFA) and cement in civil construction work which have given rise to various ecological problems. The industrial waste…

Abstract

Purpose

The use of huge quantity of natural fine aggregate (NFA) and cement in civil construction work which have given rise to various ecological problems. The industrial waste like blast furnace slag (GGBFS), fly ash, metakaolin and silica fume can be partly used as a replacement for cement and manufactured sand obtained from crusher and partly used as fine aggregate. The purpose of this paper is to predict the shear strength of concrete using artificial neural network (ANN) for concrete made by using different pozzolans and partly replacing NFA by manufactured sand (MS) which can reduce the time and experimental cost.

Design/methodology/approach

In this work, MATLAB software model is developed using neural network toolbox to predict the shear strength of concrete made by using pozzolanic materials and partly replacing NFA by manufactured sand (MS). Shear strength was experimentally calculated, and results obtained from experiment were used to develop the ANN model. A total of 131 results values were used to modeling formation, and from that 30% data record was used for testing purpose and 70% data record was used for training purpose. In total, 25 input materials properties were used to find the 28 days shear strength of concrete obtained from partly replacing cement with pozzolans and partly replacing NFA by manufactured sand (MS).

Findings

The results obtained from ANN model provide very strong accuracy to predict shear strength of concrete obtained from partly replacing cement with pozzolans and NFA by manufactured sand.

Originality/value

This research study is on determining shear strength of concrete using ANN. The use of this study is to predict the shear strength of concrete using ANN for concrete made by using different pozzolans and partly replacing NFA by manufactured sand (MS) which can reduce the time and experimental cost.

Details

Journal of Engineering, Design and Technology , vol. 19 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

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Article
Publication date: 29 November 2018

David C. Novak, James L. Sullivan, Jeremy Reed, Mladen Gagulic and Nick Van Den Berg

The ability to measure and assess “quality” is essential in building and maintaining a safe and effective transportation system. Attaining acceptable quality outcomes in…

Abstract

Purpose

The ability to measure and assess “quality” is essential in building and maintaining a safe and effective transportation system. Attaining acceptable quality outcomes in transportation projects has been a reoccurring problem at both the federal and state levels, at least partially, as a result of poorly developed, inefficient or nonexistent quality assurance/quality control (QA/QC) processes. The purpose of this paper is to develop and implement a new QA/QC process that focuses on a novel double-bounded performance-related specification (PRS) and corresponding pay factor policy that includes both lower and upper quality acceptance and payment reward boundaries for bridge concrete.

Design/methodology/approach

The authors use historical data to design different payment scenarios illustrating likely industry responses to the new PRS, and select the single scenario that best balances risk between the agency and industry. The authors then convert that payment scenario to a pay factor schedule using a search heuristic and determine statistical compliance with the PRS using percent-within-limits (PWL).

Findings

The methodology offers an innovative approach for developing an initial set of pay factors when lifecycle cost data are lacking and the PRS are new or modified. An important finding is that, with a double-bounded PRS, it is not possible to represent pay factors using the simplified table PWL currently employed in practice because each PWL value occupies two separate positions in the payment structure – one above the design target and one below it. Therefore, a more detailed set of pay factors must be employed which explicitly specify the mean sample value and the design target. The approach is demonstrated in practice for the Agency of Transportation in state of Vermont.

Research limitations/implications

The authors demonstrate a novel approach for developing a double-bounded PRS and introduce a payment incentive/disincentive policy with the goal of improving total product quality. The new pay factor policy includes both a payment penalty below the contracted price for failing to meet a specified performance criterion as well as a payment premium above the contracted price that increases as the sample product specification approaches an “ideal” design value. The PRS includes both an upper and lower acceptance boundary for the finished product as opposed to only a lower tail acceptance boundary, which is the traditional approach.

Practical implications

The authors illustrate a research collaboration between academia and a state agency that highlights the role academic research can play in advancing quality management practices. The study involves the use of actual product performance data and is operational as opposed to conceptual in nature. Finally, the authors offer important practical insights and guidance by demonstrating how a new PRS and pay factor policy can be developed without the use of site-specific historical lifecycle cost (LCC) data that include detailed manufacturing, producing and placement cost data, as data related to product performance over time. This is an important contribution, as the development and implementation of pay factor policies typically involve the use of historical LCC data. However, in many cases, these data are not available or may be incomplete.

Social implications

With the new PRS and pay factor schedule, the Agency expects shrinkage and cracking on bridge decks to decrease along with overall maintenance and rehabilitation costs. A major focus the new PRS is to actively involve industry partners in quality improvement efforts.

Originality/value

The authors focus on a major modification to an existing QA/QC process that involves the development of a new PRS and an associated pay factor policy undertaken by the Vermont Agency of Transportation. The authors use empirical data to develop a novel double bounded PRS and payment schedule for concrete and offer unique operational/practical insight and guidance by demonstrating how a new PRS and pay factor policy can be developed without the use of site-specific historical LCC. Typically, PRS for in-place concrete have only a lower tail acceptance boundary.

Details

International Journal of Quality & Reliability Management, vol. 35 no. 10
Type: Research Article
ISSN: 0265-671X

Keywords

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