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Article
Publication date: 22 July 2021

Muhammad Tahir, Arshad Hayat and Umar Burki

Environmental degradation is recognized as a serious problem globally, and hence, Saudi Arabia is no exception. This paper aims to focus on the economy of Saudi Arabia to…

Abstract

Purpose

Environmental degradation is recognized as a serious problem globally, and hence, Saudi Arabia is no exception. This paper aims to focus on the economy of Saudi Arabia to identify the determinants of environmental degradation.

Design/methodology/approach

Time series data spanning from 1971 to 2014 is used and analyzed using the recently developed autoregressive distributed lag modeling approach.

Findings

The obtained results reflected that natural resources, per person income and urbanization, have impacted environmental degradation both positively and significantly in the long run. Similarly, an insignificant negative relationship is established between trade openness and environmental degradation. Moreover, energy consumption has positively but insignificantly affected environmental degradation. In the short run, only per capita income has positively influenced environmental degradation while the rest of the variables have lost either significance levels or their direction of relationship has reversed.

Originality/value

As this is a pioneering study on the economy of Saudi Arabia, therefore, the authors assume that policymakers will find the findings of the current study very useful while formulating and implementing policies to control environmental degradation.

Details

International Journal of Energy Sector Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1750-6220

Keywords

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Article
Publication date: 10 December 2018

Shufa Yan, Biao Ma and Changsong Zheng

The purpose of constructing a degradation index (DI) is to better characterize the degradation degree of mechanical transmission compared with relying solely on spectral…

Abstract

Purpose

The purpose of constructing a degradation index (DI) is to better characterize the degradation degree of mechanical transmission compared with relying solely on spectral oil data, which leads to an accurate estimation of the failure time when the transmission no longer fulfills its function.

Design/methodology/approach

The DI is modeled using a weighted average function with two desirable properties: maximizing the monotonic trend and minimizing the variance of failure threshold between different transmissions. The method includes concentration modification, data selection and data fusion steps that lead to a reasonable mechanical transmission degradation model. The proposed methodology was verified through a case study involving multispectral oil data sampled from several power-shift steering transmissions.

Findings

The results show that the DI outperforms all spectral oil data. Compared with the existing spectral oil data-based degradation modeling approach for mechanical transmissions, the present methodology provides an accurate RUL prediction.

Research limitations/implications

There are several important directions for future research: First, more degradation data (i.e. ferrography) that are tailored to the degradation modeling of mechanical transmission need to be involved. Second, more effective degradation data selection methodologies that are applicable for multiple data types need to be developed. Third, kernel methods that can fuse the nonlinear degradation data need to be investigated.

Originality/value

The novelty of this methodology lies in integrating the multiple degradation data in a unified DI. And the main contribution of this paper is to establish a new direction in degradation modeling and RUL prediction of mechanical transmission.

Details

Industrial Lubrication and Tribology, vol. 71 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 25 June 2021

George Thiel, Flavio Griggio and Sanjay Tiku

The purpose of this paper is to describe a novel methodology for predicting reliability for consumer electronics or any other hardware systems that experience a complex…

Abstract

Purpose

The purpose of this paper is to describe a novel methodology for predicting reliability for consumer electronics or any other hardware systems that experience a complex lifecycle environmental profile.

Design/methodology/approach

This Physics-of-Failure–based three-step methodology can be used to predict the degradation rate of a population using a Monte Carlo approach. The three steps include: using an empirical equation describing the degradation of a performance metric, a degradation consistency condition and a technique to account for cumulative degradation across multiple life-cycle stress conditions (e.g. temperature, voltage, mechanical load, etc.).

Findings

Two case studies are provided to illustrate the methodology including one related to repeated touch-load induced artifacts for displays.

Originality/value

This novel methodology can be applied to a wide range of applications from mechanical systems to electrical circuits. The results can be fed into the several stages of engineering validation to speed up product qualification.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 17 May 2021

Xian Zhang, Gedong Jiang, Hao Zhang, Xialun Yun and Xuesong Mei

The purpose of this paper is to analyze the dependent competing failure reliability of harmonic drive (HD) with strength failure and degradation failure.

Abstract

Purpose

The purpose of this paper is to analyze the dependent competing failure reliability of harmonic drive (HD) with strength failure and degradation failure.

Design/methodology/approach

Based on life tests and stiffness degradation experiments, Wiener process is used to establish the accelerated performance degradation model of HD. Model parameter distribution is estimated by Bayesian inference and Markov Chain Monte Carlo (MCMC) and stiffness degradation failure samples are obtained by a three-step sampling method. Combined with strength failure samples of HD, copula function is used to describe the dependence between strength failure and stiffness degradation failure.

Findings

Strength failure occurred earlier than degradation failure under high level accelerated condition; degradation failure occurred earlier than strength failure under medium- or low-level accelerated condition. Gumbel copula is the optimum copula function for dependence modeling of strength failure and stiffness degradation failure. Dependent competing failure reliability of HD is larger than independent competing failure reliability.

Originality/value

The reliability evaluation method of dependent competing failure of HD with strength failure and degradation failure is first proposed. Performance degradation experiments during accelerated life test (ALT), step-down ALT and life test under rated condition are conducted for Wiener process based step-down accelerated performance degradation modeling.

Details

Engineering Computations, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 3 November 2020

Abdinur Ali Mohamed and Ahmed Ibrahim Nageye

The purpose of this study is to measure the effect of land degradation and the environmental changes on agricultural productivity in Somalia, as well as the other factors…

Abstract

Purpose

The purpose of this study is to measure the effect of land degradation and the environmental changes on agricultural productivity in Somalia, as well as the other factors that affect crop production in Somalia.

Design/methodology/approach

Cobb-Douglas production function assumes crop production as a dependent variable and land degradation, labor, capital, fertilizer and climate change as the explanatory variables. In this study time-series data (1962–2017) collected from the Food and Agriculture Organization and World Development Indicators were used. The unit root of the data was examined using Ng-Perron and the Lee-Strazicich methods to explore the unit root property of the breaks. Structural breaks are observed using the Chow test, and the long-run relationship between the variables is examined using Gregory and Hanssen's approach.

Findings

This study found that land degradation and climate change have a negative relationship with agriculture production in Somalia. Land degradation leads to the decline in agricultural production as the loss of one hectare of land due the depletion causes agriculture production of Somalia to fall by about five percent. Climate changes and warming of the environment lead to the reduction of agriculture production. One degree Celsius rise in the temperature leads to a three percent decline in agricultural production. Capital contributes immensely to agricultural production as one unit of additional capital raises production by seven percent. The contribution of labor to agricultural production is limited because of land contraction

Practical implications

Land degradation is a significant contributor to the decline of agricultural production. As land degradation continues to worsen, rural poverty increases, which in turn causes the rural migration and the social conflict. The government should develop land improvement programs such as increasing market orientation of the farmers, encourage private sector engagement in agribusiness and establish a regulatory framework of the land uses.

Originality/value

This study examines the structure of the time-series and specifies the break periods to determine when and where significant and sudden changes occurred within land degradation and agricultural production. The study employs advanced econometric methods, namely, Ng-Perron method and the Lee-Strazicich method to test the unit root property of the breaks. It also examines the long-run relationship between the variables using Gregory and Hanssen's approach.

Details

Management of Environmental Quality: An International Journal, vol. 32 no. 2
Type: Research Article
ISSN: 1477-7835

Keywords

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Article
Publication date: 22 April 2020

Maryam Khashij, Mohammad Mehralian and Zahra Goodarzvand Chegini

The purpose of this study to investigate acetaminophen (ACT) degradation efficiencies by using ozone/persulfate oxidation process in a batch reactor. In addition, the…

Abstract

Purpose

The purpose of this study to investigate acetaminophen (ACT) degradation efficiencies by using ozone/persulfate oxidation process in a batch reactor. In addition, the effects of various parameters on the ACT removal efficiency toward pathway inference of ACT degradation were investigated.

Design/methodology/approach

The experiments were in the 2 L glass vessels. Ozone gas with flow rate at 70 L.h−1 was produced by ozone generator. After the adjustment of the pH, various dosages of persulfate (1, 3, 5, 7 and 9 mmol.L−1) were then added to the 500 mL ACT-containing solution with 150 mg.L−1 of concentration. Afterward, ozone gas was diffused in glass vessels. The solution after reaction flowed into the storage tank for the detection. The investigated parameters included pH and the amount of ozone and persulfate addition. For comparison of the ACT degradation efficiency, ozone/persulfate, ozone and persulfate oxidation in reactor was carried out. The ACT concentration using a HPLC system equipped with 2998 PDA detector was determined at an absorbance of 242 nm.

Findings

ACT degradation percentage by using ozone or persulfate in the process were at 63.7% and 22.3%, respectively, whereas O3/persulfate oxidation process achieved degradation percentage at 91.4% in 30 min. Degradation efficiency of ACT was affected by different parameter like pH and addition of ozone or persulfate, and highest degradation obtained when pH and concentrations of persulfate and ozone was 10 and 3 mmol.L−1 and 60 mg.L−1, respectively. O3, OH and SO4− were evidenced to be the radicals for degradation of ACT through direct and indirect oxidation. Gas chromatography–mass spectrometer analysis showed intermediates including N-(3,4-dihydroxyphenyl) formamide, hydroquinone, benzoic acid, 4-methylbenzene-1,2-diol, 4-aminophenol.

Practical implications

This study provided a simple and effective way for degradation of activated ACT as emerging contaminants from aqueous solution. This way was conducted to protect environment from one of the most important and abundant pharmaceutical and personal care product in aquatic environments.

Originality/value

There are two main innovations. One is that the novel process is performed successfully for pharmaceutical degradation. The other is that the optimized conditions are obtained. In addition, the effects of various parameters on the ACT removal efficiency toward pathway inference of ACT degradation were investigated.

Details

Pigment & Resin Technology, vol. 49 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 24 January 2020

Kia Hamid Yeganeh

The purpose of this paper is to conceptualize and classify sources, manifestations and implications of environmental degradation.

Abstract

Purpose

The purpose of this paper is to conceptualize and classify sources, manifestations and implications of environmental degradation.

Design/methodology/approach

First, the typological analysis is used to conceptualize environmental degradation and its components. Then, the concepts are disaggregated into some dimensions organized in row-and-column variables and a cross-tabulated matrix is constructed. Finally, different types of environmental degradation are identified, labeled and discussed.

Findings

The study distinguishes between two types of degradation as pollution and deterioration and accordingly identifies ten types (five pairs) of environmental degradation. Furthermore, the paper presents a conceptual framework and offers insights into the dynamic interchange between the causes and effects of environmental degradation.

Originality/value

The originality/value of this study resides in reducing the ambiguities associated with the concept of environmental degradation and offering a multidimensional framework that can be used in empirical research to organize propositions, test hypotheses, analyze data and construct indexes.

Details

Management of Environmental Quality: An International Journal, vol. 31 no. 3
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 2 March 2012

Min‐You Chen, Jin‐qian Zhai, Z.Q. Lang, Feng Sun and Gang Hu

The present study is concerned with the application of a nonlinear frequency analysis approach to the detection and location of water tree degradation of power cable XLPE…

Abstract

Purpose

The present study is concerned with the application of a nonlinear frequency analysis approach to the detection and location of water tree degradation of power cable XLPE insulation without turning off electric power.

Design/methodology/approach

The use of power cable system responses to power line carrier signals are proposed to conduct the required signal analysis for damage location purpose. This technique is based on the fact that the water tree degradation in power cables can make the system behave nonlinearly. Consequently, the location of water tree degradation can be determined by detecting the position of nonlinear components in power cable systems.

Findings

A novel method has been proposed for locating water tree degradation in power cable systems; numerical simulation studies have demonstrated the effectiveness of the new technique.

Originality/value

The proposed technique has the potential to be applied in practice to more effectively resolve the power cable damage location problem.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 18 April 2008

Muawya Ahmed Hussein

The purpose of this paper is to provide estimates of damage cost for several areas of the environment. In particular: to estimate the cost of degradation as a percentage…

Abstract

Purpose

The purpose of this paper is to provide estimates of damage cost for several areas of the environment. In particular: to estimate the cost of degradation as a percentage of gross domestic product (GDP) at the national level; to enhance local capacity in environmental economics, in particular in the valuation of environmental degradation; and to provide an input to inter‐sectoral environmental priority setting.

Design/methodology/approach

To achieve the above objectives a framework was developed to estimate the cost of environmental degradation in seven countries in the region, for six categories. Estimates reflect order of magnitude and therefore represent an indication of actual damage costs. A range of estimates was provided to reflect the uncertainty of the results. Damage costs are presented in annual values (in local currencies, in US$ dollars) and as a per cent of GDP. Expressing costs as a share of GDP provides a sense of magnitude and will allow cross‐country comparison.

Findings

The damage cost of environmental degradation in Middle East and North Africa (MENA) in 2000 is estimated at US$ 9 billion per year, or 2.1‐7.4 per cent of GDP, with a mean estimate of 5.7 per cent of GDP. In addition, the damage cost to the global environment is estimated at 0.5‐1.6 of GDP, with a mean estimate of 0.9 per cent of GDP.

Research limitations/implications

Owing to data constraints, no cost estimates are provided for some impact such as: degradation associated with industrial, hazardous and hospital waste, biodiversity loss, and impact of inadequately treated wastewater, thus calculations often represent lower bound estimates.

Originality/value

This paper is a contribution in a process towards the use of environmental damage cost assessments for priority setting and as an instrument for integrating environmental consideration into economic and social development.

Details

Management of Environmental Quality: An International Journal, vol. 19 no. 3
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 1 April 1993

Y. Pan

As the physical dimensions of the devices are reduced to the submicrometer regime, the hot‐carrier reliability has become an important issue in the scaling of the p‐MOSFET…

Abstract

As the physical dimensions of the devices are reduced to the submicrometer regime, the hot‐carrier reliability has become an important issue in the scaling of the p‐MOSFET as well as the n‐MOSFET. In this paper, we present a unified approach for p‐MOSFET degradation due to the trapping of the hot electrons in the gate oxide layers. A physical analytical model, based on the pseudo two‐dimensional model, is derived for the first time to describe the linear and saturation drain current degradation. The model has been verified by comparing the calculation and the measurement from submicron p‐MOSFET's with different channel lengths and oxide thickness. There are no empirical parameters in the model. Two physical parameters: the capture cross section and the density of states of electron traps, which can be determined independently from the measured degradation characteristics, are valid for both the linear current and the saturation current degradation. The simple expression is very suitable for the predicting of the circuit reliability.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

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