Search results

1 – 10 of 13
To view the access options for this content please click here
Article

A.R. Mirhabibi, F. Moztarzadeh, A. Aghajani Bazazi, M. Solati, A. Maghsoudipour and M.H. Sarrafi

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor…

Abstract

Long afterglow Sr2MgSi2O7 (SMS) phosphor was prepared by Douby's methods at high temperature and reductive atmosphere. The excitation and emission spectra of this phosphor showed that both had broad bands and that the main emission peak at 469 nm was due to 4f‐5d transitions of Eu+2 and implied that the luminescence centres Eu+2 occupied the Sr+2 sites in the Sr2MgSi2O7 host. The phosphor doped only with Eu ions did not demonstrate the long afterglow phenomenon, but when co‐doped with Dy+3 ions in the SMS matrix, significant long afterglow was observed.

Details

Pigment & Resin Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

To view the access options for this content please click here
Article

Amir Maghsoudipour, Mohamad Hassan Sarrafi, Fathollah Moztarzadeh and Ali Aghajani Bazazi

The purpose of this paper is to investigate the effect of boric acid as a flux on the formation of the akermanite phase and optical properties of SrMgSi2O7:Eu,Dy phosphors.

Abstract

Purpose

The purpose of this paper is to investigate the effect of boric acid as a flux on the formation of the akermanite phase and optical properties of SrMgSi2O7:Eu,Dy phosphors.

Design/methodology/approach

The silicate‐based phosphor is prepared by sol‐gel method. Sr(NO3)2, Mg(NO3)2 · 6H2O, Dy2O3, Eu2O3, are added to distilled water in their stoichiometric ratio, the obtained solution are mixed with H3BO3 (in the range of 0.01‐0.5 mol%) and a polymeric compound TESO (C8H2O4Si). At the end, the phase composition and optical properties are investigated using X‐ray diffraction (XRD) and spectrophotometer analysis, respectively.

Findings

The XRD results showed that the akermanite (Sr2MgSi2O7) is the only crystalline phase which is detected in the sample containing 0.05 mol% boric acid. Increasing of boric acid does not have a great effect on the XRD patterns intensity. Spectrophotometer analysis results show three maximum at 365, 395 and 430 nm on the excitation spectra. It also shows intensity of the excitation and emission spectra increased by adding boric acid up to 0.25 mol% and a sudden drop at 0.5 mol% boric acid.

Originality/value

Using boric acid as a flux, enhances formation of akermanite phase at lower temperature with desirable optical properties and a cost‐benefit way for industrial production. In this research, optimum value of boric acid was determined using XRD data, emission and excitation spectra.

Details

Pigment & Resin Technology, vol. 39 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

To view the access options for this content please click here
Article

M. Karaminezhaad, A.H. Jafari, A. Sarrafi and Gh. Safi

To evaluate bismuth, which is inexpensive and non‐toxic, as a substitute for mercury, indium and gallium in Al‐5%Zn‐X sacrificial anode.

Abstract

Purpose

To evaluate bismuth, which is inexpensive and non‐toxic, as a substitute for mercury, indium and gallium in Al‐5%Zn‐X sacrificial anode.

Design/methodology/approach

The effect of bismuth on the electrochemical behavior of Al‐5%Zn‐Bi in the artificial sea water environment was investigated. Potentiodynamic, potentiostatic, galvanostatic, weight loss and efficiency test methods were employed. The surface of the specimens were studied by SEM and analyzed by EDAX. Image analyzer was also used.

Findings

Adding 0.3‐0.5%Bi to Al‐5%Zn alloy produces considerable active sites on the anode surface and, when the corrosion process continues, the corrosion will be uniform by joining these numerous shallow pits and a high efficiency sacrificial anode will emerge.

Research limitations/implications

Preventing segregation by good casting practice or homogenization heat treatment will be helpful to prevent unpredicted localized corrosion and investigating the effect of these processes on the performance of this new alloy is helpful. Investigating the performance of this new suggested alloy in environments like soil is highly recommended.

Practical implications

Owing to the toxicity of mercury and high price of gallium and indium, bismuth, which has a much lower price and showed a good performance in the present laboratory tests, can be a good substitute for the above mentioned elements.

Originality/value

The previous lack of a systematic research on the effect of bismuth which can be a good substitute for indium and gallium, on anodic behavior of aluminum gives this paper its high value.

Details

Anti-Corrosion Methods and Materials, vol. 53 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

To view the access options for this content please click here
Article

Amirreza Farahbod and Uğur Dağli

From an architectonic point of view, the identity of Iranian houses has become more enriched itself throughout history. Primarily, during the Qajardynasty (1785-1925)as a…

Abstract

From an architectonic point of view, the identity of Iranian houses has become more enriched itself throughout history. Primarily, during the Qajardynasty (1785-1925)as a consequence of the social, political, and economical changes which took place, there was a turning point from traditional architectural construction to the modernism principals of construction. In this regard, this studyaims toexplore the importance of the compatibility of the termidentity of architecture in the transformation age (a period which led tothe turning point in the history of Iranian architecture) bydescriptive (including comparative and co-relational methods) and explanative-analytical methods.

By evaluating the spatial characteristics of TraditionalIranian Houses (TIH), the study has developed a method of assessingthe architectural identity of the Qajar era. It alsointroduceda Top-down and Bottom-up processing method as the two main factors in shapingthe identityofan architectural style. By comparing both the objective and subjective indicators of shapingthe identity of TIH, the study also revealed that, in transitioning from the traditional construction to modern, the physical characteristics of the houses might change considerably, whilst lifestyles will not change at the same speed.

Details

Open House International, vol. 42 no. 4
Type: Research Article
ISSN: 0168-2601

Keywords

To view the access options for this content please click here
Article

George Hayward and John Masterson

This article looks at how capital equipment innovations are adopted. The reception of innovations by adoptors and non‐adoptors provides “profiles” of the characteristics…

Abstract

This article looks at how capital equipment innovations are adopted. The reception of innovations by adoptors and non‐adoptors provides “profiles” of the characteristics of innovations, which can highlight good selling features and identify markets.

Details

Management Decision, vol. 25 no. 4
Type: Research Article
ISSN: 0025-1747

To view the access options for this content please click here
Article

Elisan dos Santos Magalhaes, Cristiano Pedro da Silva, Ana Lúcia Fernandes Lima e Silva and Sandro Metrevelle Marcondes Lima e Silva

The purpose of this article is the determination of the temperature fields in a weld region has always been an obstacle to the improvement of welding processes. As an…

Abstract

Purpose

The purpose of this article is the determination of the temperature fields in a weld region has always been an obstacle to the improvement of welding processes. As an alternative, the use of inverse problems to determine the heat flux during the welding process allows an analysis of these processes.

Design/methodology/approach

This paper studies an alternative for the thermal analysis of the tungsten inert gas welding process on a 6,060 T5 aluminum alloy. For this purpose, a C++ code was developed, based on a transient three-dimensional heat transfer model. To estimate the amount of heat delivered to the plate, the specification function technique was used. Lab experiments were carried out to validate the methodology. A different experimental methodology is proposed to estimate the emissivity (radiation coefficient).

Findings

The maximum difference between experimental and numerical temperatures is lower than 5 per cent. The determined emissivity value for the aluminum 6,060 T5 presented a good agreement with literature values. The thermal fields were analyzed as function of the positive polarity. The specification function method proved to be an adequate tool for heat input estimation in welding analysis.

Originality/value

The proposed methodology proves to be a cheaper way to estimate the heat flux on the sample. The estimated power curves for the welding process are presented. The methodology to calculate the emissivity (radiation coefficient) was validated.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

To view the access options for this content please click here
Article

Serdar Karabati and Arzu Iseri Say

Work and societal values were examined through a 72‐item survey for a sample of nearly six hundred managers, business owners, and professionals in Turkey. Factor analyses…

Abstract

Work and societal values were examined through a 72‐item survey for a sample of nearly six hundred managers, business owners, and professionals in Turkey. Factor analyses revealed eleven work value dimensions and eleven societal value dimensions. A second order factor analysis revealed nine meta‐dimensions among which indigenous concepts of cynical fatalism and under‐ambitious work deserve further attention. Findings also validate comparatively well‐established notions such as paternalism and trust.

Details

Cross Cultural Management: An International Journal, vol. 12 no. 2
Type: Research Article
ISSN: 1352-7606

Keywords

To view the access options for this content please click here
Article

Jaroslav Mackerle

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming…

Abstract

Purpose

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

Design/methodology/approach

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Findings

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Originality/value

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

Details

Engineering Computations, vol. 22 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article

Joshua R. Muckensturm and Dave C. Longhorn

This paper introduces a new heuristic algorithm that aims to solve the military route vulnerability problem, which involves assessing the vulnerability of military cargo…

Abstract

Purpose

This paper introduces a new heuristic algorithm that aims to solve the military route vulnerability problem, which involves assessing the vulnerability of military cargo flowing over roads and railways subject to enemy interdiction.

Design/methodology/approach

Graph theory, a heuristic and a binary integer program are used in this paper.

Findings

This work allows transportation analysts at the United States Transportation Command to identify a relatively small number of roads or railways that, if interdicted by an enemy, could disrupt the flow of military cargo within any theater of operation.

Research limitations/implications

This research does not capture aspects of time, such as the reality that cargo requirements and enemy threats may fluctuate each day of the contingency.

Practical implications

This work provides military logistics planners and decision-makers with a vulnerability assessment of theater distribution routes, including insights into which specific roads and railways may require protection to ensure the successful delivery of cargo from ports of debarkation to final destinations.

Originality/value

This work merges network connectivity and flow characteristics with enemy threat assessments to identify militarily-useful roads and railways most vulnerable to enemy interdictions. A geographic combatant command recently used this specific research approach to support their request for rapid rail repair capability.

Details

Journal of Defense Analytics and Logistics, vol. 3 no. 1
Type: Research Article
ISSN: 2399-6439

Keywords

To view the access options for this content please click here

Abstract

Purpose

The purpose of this paper is to improve the lattice Boltzmann method’s ability to simulate a microflow under constant heat flux.

Design/methodology/approach

Develop the thermal lattice Boltzmann method based on double population of hydrodynamic and thermal distribution functions.

Findings

The buoyancy forces, caused by gravity, can change the hydrodynamic properties of the flow. As a result, the gravity term was included in the Boltzmann equation as an external force, and the equations were rewritten under new conditions.

Originality/value

To the best of the authors’ knowledge, the current study is the first attempt to investigate mixed-convection heat transfer in an inclined microchannel in a slip flow regime.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of 13