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Article
Publication date: 1 March 1996

Ayech Benjeddou and Mohamed Ali Hamdi

Presents a new B‐spline finite element for the dynamic analysis of unsymmetrical sandwich shells of revolution. The formulation takes account of the membrane and bending…

Abstract

Presents a new B‐spline finite element for the dynamic analysis of unsymmetrical sandwich shells of revolution. The formulation takes account of the membrane and bending effects in isotropic or orthotropic elastic facings, and membrane, bending and transverse shearing effects in an isotropic or othotropic elastic core. Both geometry and local displacements are interpolated by a set of B‐spline functions. The main aspects added by the sandwich structure of the element are the transverse shearing and membrane‐bending coupling effects in the core. These are well represented by a set of new variables which are the mean end relative in‐plane displacements of the facing middle surfaces. Together with the transverse displacement, these variables constitute the degrees of freedom (dofs) of this new B‐spline sandwich element. The finite elements are grouped into super‐elements with C1 continuity to obtain the whole finite element model. For each super‐element a total of five dofs per node is then obtained except for its end nodes where the derivatives of these dofs with respect to the meridional co‐ordinate are added. This choice reduces to a minimum the total number of dofs in comparison to existing sandwich elements. Evaluates the efficiency and accuracy of the proposed element through several benchmark examples. Compares the results with the analytical and numerical solutions found in the literature. A very satisfactory behaviour of the element was observed in all test cases.

Details

Engineering Computations, vol. 13 no. 2/3/4
Type: Research Article
ISSN: 0264-4401

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Book part
Publication date: 15 January 2013

Peter J. Spiro

This contribution critiques U.S. practices respecting birth citizenship. It first describes the logic of territorial birthright citizenship. The practice makes sense only…

Abstract

This contribution critiques U.S. practices respecting birth citizenship. It first describes the logic of territorial birthright citizenship. The practice makes sense only insofar as place of birth has supplied a proxy for community membership. But many who are born in the United States leave permanently at an early age. It is not clear why they should be able to take their citizenship with them. The paper also critiques the liberalized basis for acquiring citizenship on the basis of parentage. In both cases, birth citizenship creates an increasing disconnect between the formal and organic boundaries of community. This disconnect could be addressed by the adoption of presence requirements beyond birth. Presence requirements would be consistent with liberal values to the extent they would strengthen the solidarities of the liberal state. However, it is unclear that presence gives rise to such solidarities. It is also improbable that presence requirements will be adopted. This both evidences and reinforces the declining salience of citizenship.

Details

Special Issue: Who Belongs? Immigration, Citizenship, and the Constitution of Legality
Type: Book
ISBN: 978-1-78190-432-9

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Book part
Publication date: 6 September 2018

Lin-Sea Lau, Chee-Keong Choong and Cheong-Fatt Ng

This study aims to examine the Environmental Kuznets Curve (EKC) hypothesis in the case of 100 developed and developing nations by taking into account the role of…

Abstract

This study aims to examine the Environmental Kuznets Curve (EKC) hypothesis in the case of 100 developed and developing nations by taking into account the role of institutional quality (IQ). Using generalized method of moments (GMM) estimators, we find an inverted U-shaped relationship between economic growth and carbon dioxide (CO2) emissions only in the developed world but not in the developing nations. It is also revealed that control of corruption plays a vital role in reducing CO2 emissions in high income countries. Furthermore, rule of law is found to have a beneficial effect on the environment in all countries except for low income countries. Overall, our results confirm the importance of IQ in reducing CO2 emissions. Additionally, foreign direct investment contributes to CO2 reduction in rich countries while deteriorates the environmental quality in developing nations. Trade openness was shown to exert a positive impact on environmental quality in developing countries. These findings can be of great importance to policy makers of different income groups in designing appropriate economic and environmental policies toward the dual goals of high growth and low pollution.

Details

Advances in Pacific Basin Business, Economics and Finance
Type: Book
ISBN: 978-1-78756-446-6

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Article
Publication date: 17 April 2020

Ankur V. Bansod, Awanikumar P. Patil and Sourabh Shukla

Low nickel austenitic stainless steel (ASS) has attracted much attention worldwide because of its economical price. This study aims to investigate the effect of different…

Abstract

Purpose

Low nickel austenitic stainless steel (ASS) has attracted much attention worldwide because of its economical price. This study aims to investigate the effect of different corrosive environments on the corrosion behavior of chrome-manganese (Cr-Mn) ASS. The tests were carried out as a function of H2SO4 concentrations, temperature and addition of ammonium thiocyanate (NH4SCN) (0.01 M). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used to study the corrosion behavior of Cr-Mn ASS. It was observed that with increasing H2SO4 concentration, temperature and with the addition of NH4SCN solution, icorr, icrit and ipassive values increased. EIS data show decreasing charge transfer resistance value with increasing concentration and temperature. Higher corrosion rate with increasing temperature and concentration of H2SO4 is related to the anions (SO42−), which is responsible for reducing the stability of passive films. With the presence of 0.01 M NH4SCN thiocyanate (SCN anion), there is a higher dilution of the passive film resulting in a higher corrosion rate. Energy-dispersive spectroscopy (EDS) analysis reveals the adsorption of sulfur on the surface in NH4SCN containing a solution. The significant presence of counter ions and the adsorbed sulfur species on the steel surface play a vital role in corrosion behavior.

Design/methodology/approach

All the experiments were performed on a 3 mm thick sheet of Cr-Mn ASS (202 ASS) in hot rolled condition. The samples were then annealed at 1,050°C for 1 h, followed by water quenching. For microstructural examination, they were electrochemically etched in 10 Wt.% oxalic acid solution at 1 amp for 90 s. A computer-controlled Potentiostat (Biologic VMP-300) was used. After the cell was set up, the working electrode (WE) was electrostatically cleaned at −1 V vs saturated calomel electrode (SCE) for 30 s to remove the air-formed film. Then, WE were allowed to attain stable open circuit potential (OCP) for 1 h, following by the EIS test and potentiodynamic polarization test. The polarization test was started from a cathodic potential (−1.2 V vs SCE) and continued up to an anodic potential (1.6 V vs SCE) a scan rate of 0.1667 mV/s. EIS experiment was conducted on the same instrument by using a sinusoidal AC signal of 10 mV in a frequency range of 1,000,000 to 0.01 Hz at OCP.

Findings

Potentiodynamic polarization graph shows that with the increase in sulphuric acid concentration. Increasing temperature from 20°C to 80°C in 0.5 M H2SO4 solution increases the corrosion rate (icorr) of Cr-Mn ASS. On the addition of 0.01 M NH4SCN to the sulfuric acid solution (0.1, 0.5 and 1 M) the corrosion rate increases drastically almost four to five times. EDS and XRD analysis shows the presence of sulfur over the oxide film and preferential site for dissolution of Cr and Mn at the steel surface when NH4SCN is added to the sulfuric acid solution.

Originality/value

A study on the corrosion behavior of Cr-Mn ASS is scanty according to the author’s knowledge. Therefore, the present study will investigate the corrosion behavior of Cr-Mn ASS on SO4−2 anions, temperature and the addition of SCN ion in sulfuric acid.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 5 April 2013

Kevin Yessian, Pat DeLaquil, Bruno Merven, Maurizio Gargiulo and Gary Goldstein

An economic assessment was performed of the potential for clean energy options to contribute to the power and desalination needs in the State of Kuwait over the next 20 to…

Abstract

Purpose

An economic assessment was performed of the potential for clean energy options to contribute to the power and desalination needs in the State of Kuwait over the next 20 to 40 years. The paper aims to summarize two analyses that were performed for the Kuwait Institute for Scientific Research to develop a strategy promoting renewable energy and evaluating alternative technologies including nuclear energy.

Design/methodology/approach

The analyses were performed using a power and water model for Kuwait that was constructed using the International Energy Agency – Energy Technology Systems Analysis Programme (IEA‐ETSAP) TIMES modeling framework. Data provided by the Ministry of Electricity and Water (MEW) and the Kuwait Petroleum Company (KPC) characterizes the projected demand for power and water; the existing and planned power generation and water desalination plants, including the expected retirement of existing plants; and future fossil fuel prices and availability. New power generation options – including renewable energy (RE), nuclear, combined cycle gas turbines (CCGT) and reheat steam power plants (RHSPP) – were compared in this least‐cost optimization framework.

Findings

The model results indicate that by 2030 the cost‐effective RE share is 11 percent of electricity generation in the reference case and 8 percent in the case with the nuclear option. The RE technologies alone provide a 2030 net‐back value compared to the reference case of US$2.35 billion, while in the nuclear case they increase the 2030 net‐back value by an additional US$1.5 billion. Increasing the RE share, as a government policy, to 10 percent, 15 percent and 20 percent, decreases the 2030 netback benefit by US$1.0, $3.6 and $8.3 billion, respectively.

Research limitations/implications

Sensitivity runs based on scenarios that assume higher RE costs or lower availability, lower demand growth, lower oil and gas prices, higher nuclear plant investment costs, and RE capacity credit were analyzed.

Practical implications

The analysis provides a compelling economic basis for initiating a renewable energy program in the State of Kuwait. However, these forecasted benefits will only materialize to the extent the projected RE investments are achieved if they begin in earnest soon.

Originality/value

The analysis identifies a cost‐effective share of renewable energy use in Kuwait as about 11 percent of electricity generation in 2030. The investment in renewable energy provides the State of Kuwait with a net‐back value of US$2.35 billion, due to the fuel savings that are generated by using renewables.

Details

International Journal of Energy Sector Management, vol. 7 no. 1
Type: Research Article
ISSN: 1750-6220

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Article
Publication date: 9 March 2015

Tae-Bong Lee and Min-Nyeon Kim

– The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings.

Abstract

Purpose

The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings.

Design/methodology/approach

For the mode calculation, equations are newly defined by applying vertical boundary condition on the assumption that transverse electric modes are generated in the structure. After finding modes, near field patterns are calculated using the wave number and coefficient of the mode.

Findings

Additionally, the results from these calculations are compared with that of the rigorous-coupled method. Finally, far field patterns are derived by applying fast Fourier transform to near field patterns and also compared with the results of rigorous-coupled method.

Research limitations/implications

For convenience of coordinate, we use rectangular coordinate, though the shape of radome is a hemisphere.

Practical implications

In this paper, the authors derive more exact near field patterns without the assumption of infiniteness so that these results can be used practically for a making real frequency-selective structure.

Originality/value

Conventional periodic finite dielectric gratings analysis has been done using Floquet–Bloch wave theory, coupled-mode, rigorous-coupled method which is based on the assumption of infiniteness of the structure.

Details

Journal of Systems and Information Technology, vol. 17 no. 1
Type: Research Article
ISSN: 1328-7265

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Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 March 2002

Jaroslav Mackerle

Gives a bibliographical review of the finite element analyses of sandwich structures from the theoretical as well as practical points of view. Both isotropic and composite…

Abstract

Gives a bibliographical review of the finite element analyses of sandwich structures from the theoretical as well as practical points of view. Both isotropic and composite materials are considered. Topics include: material and mechanical properties of sandwich structures; vibration, dynamic response and impact problems; heat transfer and thermomechanical responses; contact problems; fracture mechanics, fatigue and damage; stability problems; special finite elements developed for the analysis of sandwich structures; analysis of sandwich beams, plates, panels and shells; specific applications in various fields of engineering; other topics. The analysis of cellular solids is also included. The bibliography at the end of this paper contains 655 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1980 and 2001.

Details

Engineering Computations, vol. 19 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 November 2006

Abdel Salam Hamdy

To develop new eco‐environmentally friendly surface treatments based on cerate compounds as alternatives to the process involving toxic chromates for the corrosion…

Abstract

Purpose

To develop new eco‐environmentally friendly surface treatments based on cerate compounds as alternatives to the process involving toxic chromates for the corrosion protection of magnesium alloys.

Design/methodology/approach

A treatment process in which a surface was alkaline‐etched prior to ceria treatment is proposed. The process involves cleaning, etching in potassium hydroxide followed by treatment in ceria conversion coatings. The effect of surface preparation prior to ceria treatment on the corrosion resistance of AZ91D in 3.5 per cent NaCl solution was measured using AC impedance spectroscopy and DC polarization techniques. Surface examination was performed by scanning electron microscopy, energy dispersive X‐ray.

Findings

It was shown that the ceria treatment can be used as a localized corrosion inhibitor for alloy AZ91D in NaCl solution. The level of inhibition strongly depended on the cerium concentration. Moreover, ceria treatments improved the pitting corrosion resistance due to the formation of protective oxide films which act as a barrier to oxygen diffusion to the metal surface. According to the EIS and polarization measurements, alkaline etching in KOH is more effective in reducing the pitting corrosion of AZ91D than was HCl. It was shown that surface treatment in alkaline solution (KOH) prior to ceria treatments played an important role in inhibiting the active surface sites, rejecting the chloride ions from the surface and forming uniformly distributed oxide film.

Originality/value

Ceria conversion coatings seem very promising as alternatives to toxic chromating for the corrosion protection of magnesium alloys in NaCl solution.

Details

Anti-Corrosion Methods and Materials, vol. 53 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 12 April 2021

Tarik Saikouk, Nejib Fattam, Gunasekaran Angappa and Ahmed Hamdi

This paper aims to identify and explain the link between relational dynamics and the development of coordination capabilities of Fourth-Party Logistics Providers (4PL…

Abstract

Purpose

This paper aims to identify and explain the link between relational dynamics and the development of coordination capabilities of Fourth-Party Logistics Providers (4PL) within a supply chain (SC). We aim to demonstrate the critical role relational dynamics can play in converting trust from interpersonal to inter-organizational level and facilitate the improvement of capabilities to coordinate customer's SC activities.

Design/methodology/approach

Using semi-structured interviews with 78 logistics managers operating in 45 different logistics service providers located in France, we developed a set of propositions and built a conceptual framework. Exploratory qualitative research in the form of propositional discourse analysis (PDA) is used to develop propositions in our research to contribute to theory in supply chain management (SCM).

Findings

Results indicate that both interpersonal and inter-organizational trust is a convertible capital. Based on their dynamic interactions, these two levels of trust endow the supply chain partners with economic benefits that would otherwise be highly costly or even practically extremely difficult to achieve through complex socio-economic transactions (meso-social level).

Research limitations/implications

Future research may test our conceptual model using primary and secondary data and conduct longitudinal case studies that are necessary to triangulate our results and thus strengthen our conclusions. The prospect of adding control variables to our model would be of considerable importance.

Practical implications

Our results suggest that “4PL” need to invest more in interpersonal relations to facilitate collaboration with their clients and enhance their capability to coordinate and manage customer's supply chain activities. The ability to convert interpersonal trust represents an invaluable capital contributing to the achievement of above-normal profits.

Originality/value

This work contributes to a better understanding of the coordination of supply chain activities through the development, mobilization and maintenance of social capital. While previous research explained the importance of trust in SCM, this paper explores and studies the process of converting interpersonal trust into social capital mobilized at the supply chain level. We add to the existing literature on structural and relational dimensions of social capital by offering a process-based explanation of the conversion of interpersonal trust into inter-organizational trust and its role in facilitating collaboration in logistics services.

Details

The International Journal of Logistics Management, vol. 32 no. 3
Type: Research Article
ISSN: 0957-4093

Keywords

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