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Book part
Publication date: 27 August 2014

Damian Tago, Henrik Andersson and Nicolas Treich

This study contributes to the understanding of the health effects of pesticides exposure and of how pesticides have been and should be regulated.

Abstract

Purpose

This study contributes to the understanding of the health effects of pesticides exposure and of how pesticides have been and should be regulated.

Design/methodology/approach

This study presents literature reviews for the period 2000–2013 on (i) the health effects of pesticides and on (ii) preference valuation of health risks related to pesticides, as well as a discussion of the role of benefit-cost analysis applied to pesticide regulatory measures.

Findings

This study indicates that the health literature has focused on individuals with direct exposure to pesticides, i.e. farmers, while the literature on preference valuation has focused on those with indirect exposure, i.e. consumers. The discussion highlights the need to clarify the rationale for regulating pesticides, the role of risk perceptions in benefit-cost analysis, and the importance of inter-disciplinary research in this area.

Originality/value

This study relates findings of different disciplines (health, economics, public policy) regarding pesticides, and identifies gaps for future research.

Details

Preference Measurement in Health
Type: Book
ISBN: 978-1-78441-029-2

Keywords

Article
Publication date: 1 June 1992

KAMEL M. AL‐KHALIL, THEO G. JR. KEITH and KENNETH J. DE WITT

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct…

Abstract

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct impingement, into individual rivulets. The wetness factor distribution resulting from the film breakup and rivulet configuration on the surface are predicted in the numerical solution procedure. The solid wall is modelled as a multi‐layer structure and the anti‐icing system used is of the thermal type utilizing hot air and/or electrical heating elements embedded within the layers. Details of the calculation procedure and the methods used are presented.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 2 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 27 August 2019

Yijiang Peng, Xiyun Chen, Liping Ying and Mahmoud M.A. Kamel

Based on the base force element method, a two-dimensional random circle aggregate model with Monte Carlo principle is proposed to carry out research on softening curve in…

Abstract

Purpose

Based on the base force element method, a two-dimensional random circle aggregate model with Monte Carlo principle is proposed to carry out research on softening curve in meso-level.

Design/methodology/approach

The meso-level structure of recycled concrete is considered as the five-phase materials composed of aggregate, old interfacial transition zone, old mortar, new interfacial transition zone and new mortar. A multi-polyline damage model is adopted to describe the nonlinear mechanical behavior of recycled concrete material. The destruction state of the element is determined by the first strength theory. The research studies on damage process of recycled concrete under the loading conditions of uniaxial tension were established using the base force element method.

Findings

The softening curves of recycled concrete are obtained, which are in good agreement with experiment results. Simulation results show that the macroscopic mechanical properties and failure mechanism can analyze more reasonably from mesoscopic structure. Besides that, it can be investigated from the numerical results of the size effect in recycled concrete through the mesoscopic heterogeneity. Furthermore, the form of aggregate distribution has influence on the crack path but little effect on the tensile strength of recycled concrete.

Originality/value

The results show that the base force element method has been successfully applied to the study of softening curve of recycled concrete under uniaxial tension.

Details

Engineering Computations, vol. 36 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 13 February 2020

Liping Ying, Yijiang Peng and Mahmoud M.A. Kamel

Based on the random aggregate model of recycled aggregate concrete (RAC), this paper aims to focus on the effect of loading rate on the failure pattern and the macroscopic…

Abstract

Purpose

Based on the random aggregate model of recycled aggregate concrete (RAC), this paper aims to focus on the effect of loading rate on the failure pattern and the macroscopic mechanical properties.

Design/methodology/approach

RAC is regarded as a five-phase inhomogeneous composite material at the mesoscopic level. The number and position of the aggregates are modeled by the Walraven formula and Monte–Carlo stochastic method, respectively. The RAC specimen is divided by the finite-element mesh to establish the dynamic base force element model. In this model, the element mechanical parameters of each material phase satisfy Weibull distribution. To simulate and analyze the dynamic mechanical behavior of RAC under axial tension, flexural tension and shear tension, the dynamic tensile modes of the double-notched specimens, the simply supported beam and the L specimens are modeled, respectively. In addition, the different concrete samples are numerically investigated under different loading rates.

Findings

The failure strength and failure pattern of RAC have strong rate-dependent characteristics because of the inhomogeneity and the inertial effect of the material.

Originality/value

The dynamic base force element method has been successfully applied to the study of recycled concrete.

Details

Engineering Computations, vol. 37 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 January 1991

KAMEL M. AL‐KHALIL, THEO G. JR. KEITH and KENNETH J. DE WITT

The hydrodynamics and thermal characteristics of a laminar rivulet flow down a vertical surface are investigated. The velocity distribution within a rivulet is determined…

Abstract

The hydrodynamics and thermal characteristics of a laminar rivulet flow down a vertical surface are investigated. The velocity distribution within a rivulet is determined numerically by the use of a finite element method. In turn, a regression analysis is performed to fit the numerical data with an assumed closed form function. The breakup of a thin liquid film into rivulets is also considered. Heat transfer characteristics are determined. Nusselt numbers were obtained for the two cases of prescribed constant wall temperature and constant wall heat flux.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 1 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 28 May 2021

Mohammad Kamel Alomari

This paper aims to debate the main factors influencing trust in mobile government (m-government) in the developing country of Jordan. The transformation from government…

Abstract

Purpose

This paper aims to debate the main factors influencing trust in mobile government (m-government) in the developing country of Jordan. The transformation from government services offered through a government website to services offered via smartphone devices needs further investigation to better understand the factors that might influence citizens’ trust in m-government, in particular, young citizens. This paper presents the concept of m-government and reports on a study of the main predictors affecting citizens’ trust in it. The theoretical framework used is based on the unified theory of acceptance and use of technology (UTAUT).

Design/methodology/approach

A survey study of 510 Jordanian young citizens, who had access to the internet and were smartphone users, investigated the influence of the identified factors on their trust in m-government. The hypotheses testing used multiple regression analysis.

Findings

Contrary to previous claims reported in relation to facilitating conditions, the following predictors: trust in government, word of mouth (WOM), social influence and facilitating conditions were found to be significant factors in predicting Jordanian citizens’ trust in m-government services.

Originality/value

This is one of few studies to investigate what influences trust in m-government by citizens in Jordan. The current research significantly contributes to the literature by incorporating factors from the UTAUT model with personal perception factors to elucidate m-government adoption. The integration of UTAUT with factors such as “WOM”, is a direction that can be followed in research on the adoption of and trust in e-government and m-government by citizens in any social community. This study clearly identities the relationship between m-government trust and the WOM construct, which is rarely discussed in this type of research context. Although the facilitating conditions construct is claimed to be non-significant in the presence of performance expectancy and effort expectancy, the current research shows the importance of including the facilitating conditions construct when considering the topic of m-government trust in Jordan. Finally, this paper provides a foundation for future empirical studies on the adoption of m-government.

Details

Transforming Government: People, Process and Policy, vol. 16 no. 1
Type: Research Article
ISSN: 1750-6166

Keywords

Article
Publication date: 28 May 2021

Mahmoud Abdelrahman Kamel, Mohamed El-Sayed Mousa and Randa Mohamed Hamdy

This study used data envelopment analysis (DEA) models to measure financial efficiency of twelve commercial banks listed in the Egyptian stock exchange (CBLSE), along with…

Abstract

Purpose

This study used data envelopment analysis (DEA) models to measure financial efficiency of twelve commercial banks listed in the Egyptian stock exchange (CBLSE), along with evaluating changes to the financial efficiency during the period 2017–2019.

Design/methodology/approach

The study used BCC-I, cross-efficiency, super-efficiency models, and Malmquist productivity index (MPI) to assess financial efficiency of the examined banks. The available data from both inputs and outputs were analyzed using R. studio V.I.3. 1056 software.

Findings

Out of twelve banks examined, only four banks were efficient under BCC-I model over different years of the study period; however, only one bank (CIB) appeared to be the most efficient compared to other peers in the study sample. Moreover, MPI results revealed decreased financial efficiency during the study period, due to the decreased technological innovation, except for HDB. Tobit regression results confirmed that total assets and total equity are significant factors impacted financial efficiency of CBLSE.

Practical implications

This study sheds light on the importance of evaluating financial efficiency of CBLSE to all stakeholders, to pinpoint weaknesses in banks' performance, and for evaluating financial policies and investment decisions.

Originality/value

Several studies sought to implement different models of DEA to assess banking performance in different regions of the world, but very few studies examined financial efficiency of banks. To the best of authors’ knowledge, this study is one of those few that addressed financial efficiency of banks in Egypt.

Details

International Journal of Productivity and Performance Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1741-0401

Keywords

Article
Publication date: 1 February 2012

M.M. Kamel, H.M. Helmy, Alia A. Shakour and S.S. Rashed

Wool yarns are dyed with natural colouring matter that is extracted from cochineal, turmeric and madder, and mordanted with different mordants by using the exhaustion…

Abstract

Wool yarns are dyed with natural colouring matter that is extracted from cochineal, turmeric and madder, and mordanted with different mordants by using the exhaustion method. Many measurements of mordanted dyed wool samples have been carried out after exposure to air and light for different periods of time in the time frame of one year in an urban area (Helwan city). The variables that are measured include changes in colour and physical properties (tensile strength, tenacity and elongation) of mordanted dyed wool samples. Also, air pollution in Helwan city is determined by studying suspended and deposited particulate matter and sulpher dioxide concentrations.

Details

Research Journal of Textile and Apparel, vol. 16 no. 1
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 20 August 2021

Mohamed El-Sayed Mousa and Mahmoud Abdelrahman Kamel

This study aims to develop and test a framework for integration between data envelopment analysis (DEA) and artificial neural networks (ANN) to predict the best financial…

Abstract

Purpose

This study aims to develop and test a framework for integration between data envelopment analysis (DEA) and artificial neural networks (ANN) to predict the best financial performance concerning return on assets and return on equity for banks listed on the Egyptian Exchange, to help managers generate what-if scenarios? For performance improvement and benchmarking.

Design/methodology/approach

The study empirically tested the three-stage DEA-ANN framework. First, DEA was used as a preprocessor of the banks’ efficiency scores. Second, a back-propagation neural network as a multi-layer perceptron-ANN’s model was designed using expected data sets from DEA to learn optimal performance patterns. Third, the superior performance of banks was forecasted.

Findings

The results indicated that banks are not operating under their most productive operations, and there is room for potential improvements to reach outperformance. Moreover, the neural networks’ empirical test results showed high correlations between the actual and expected values, with low prediction errors in both the test and prediction phases.

Practical implications

Based on best performance prediction, banks can generate alternative scenarios for future performance improvement and enabling managers to develop effective strategies for performance control under uncertainty and limited data. Besides, supporting the decision-making process and proactive management of performance.

Originality/value

Despite the growing research stream supporting DEA-ANN integration applications, these are still limited and scarce, especially in the Middle East and North Africa region. Therefore, the study trying to fill this gap to help bank managers predict the best financial performance.

Details

Journal of Modelling in Management, vol. 17 no. 3
Type: Research Article
ISSN: 1746-5664

Keywords

Article
Publication date: 19 August 2021

B. Norerama D. Pagukuman and M. Kamel Wan Ibrahim

The purpose of this paper is to present and discuss the external factors of the solar dryer design that influenced the thermal efficiency of the solar dryer that…

Abstract

Purpose

The purpose of this paper is to present and discuss the external factors of the solar dryer design that influenced the thermal efficiency of the solar dryer that contribute to the better quality of dried food products.

Design/methodology/approach

From the reviewed works of literature, the external factors including the drying temperature, airflow rate and relative humidity have significant effects to increase the rate of moisture diffusivity of the freshly harvested products during the drying process. The proper controls of airflow rate (Q), velocity (V), relative humidity (RH%) and drying temperature (°C) can influence the dried product quality. The dehydration ratio is the procedure to measure the quality of the dried food product.

Findings

The indirect solar dryer including the mixed-mode, hybrid and integrated was found shorter in drying time and energy-intensive compared to sun drying and direct drying. The recommended drying temperature is from 35.5°C to 70°C with 1–2 m/s velocity and 20%–60% relative humidity. The optimum thermal efficiency can be reached by additional devices, including solar collectors and solar accumulators. It gives a simultaneous effect and elongated the drying temperature 8%–10% higher than ambient temperature with 34%–40% energy saving. The recommended airflow rate for drying is 0.1204 to 0.0894 kg/s. Meanwhile, an airflow rate at 0.035–0.04 kg/m2 is recommended for an optimum drying kinetic performance.

Research limitations/implications

This paper discusses the influence of the external factors of the solar dryer design on the thermal performance of the solar dryer and final dried food products quality. Therefore, the findings cannot serve as a statistical generalization but should instead be viewed as the quantitative validation subjected to fundamentals of the solar dryer design process and qualitative observation of the dried food product quality.

Practical implications

A well-designed of solar dryer with low operating and initial fabrication cost, which is simple to operate is useful for the farmers to preserve surplus harvested crops to an acceptable and marketable foods product. The optimization of the external and internal factors can contribute to solar dryer thermal performance that later provides an organoleptic drying condition that results in good quality of dried product and better drying process. The recommended drying temperature for a drying method is between 35°C up to 70°C. Drying at 65.56°C was effective to kill microorganisms. Meanwhile, drying at 50°C consider as average drying temperature. The recommended airflow rate for drying is 0.1204 to 0.0894 kg/s. Meanwhile, air flowrate at 0.035–0.04 kg/m2 is recommended for optimum drying kinetic performance. The recommended value of aspect ratio and mass flow rate is 200 to 300 for an optimum evaporation rate. The good quality of dried products and good performance of solar dryers can be developed by proper control of airflow rate (Q), velocity (V), relative humidity (RH%) and drying temperature (°C).

Social implications

The proper control of the drying temperature, relative humidity and airflow rate during the drying process will influence the final dried food products in terms of shape, color, aroma, texture, rupture and nutritious value. It is crucial to control the drying parameters because over-drying caused an increment of energy cost and reduces the dry matter. The quick-drying will disturb the chemical process during fermentation to be completed.

Originality/value

This study identifies the potential of the solar drying method for dehydrating agricultural produces for later use with the organoleptic drying process. The organoleptic drying process can reduce mold growth by promising an effective diffusion of moisture from freshly harvested products. The research paper gives useful understandings that well-designed solar drying technology gives a significant effect on dried product quality.

Details

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

Keywords

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