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Heat treatment by quenching of individual metallic parts with multiple impinging gas jets is an environmentally friendly alternative to conventional surface hardening and quenching in liquids. In the present investigation the gas flow field and simultaneous heat transfer process in gas quenching is studied by numerical simulation for surface treatment of a cylindrical sample geometry. Aim of the investigation is the evaluation of optimized flow conditions and nozzle arrangements to achieve: a maximum overall heat release (high integral heat transfer rates) to maximize the quenching efficiency; a local smooth distribution of the cooling process (spatially homogeneous heat transfer) for avoidance of spatial hardness variations. These aims are achieved by derivation of an optimized nozzle arrangement and appropriate operation conditions of the gas jet array with respect to the three dimensional sample geometry of a cylinder to be quenched.

The purpose of this paper is to quantitatively document and synthesize the knowledge base on leading school change and improvement (LSCI).

The authors employed bibliometric analysis to evaluate 1,613 SCOPUS-indexed documents on LSCI published between 1960 and the end of 2017. In addition to descriptive analysis of basic features of the knowledge base, the review also employed citation and co-citation analyses of authors, journals and documents. Author co-citation analysis (ACA) was used reveal the intellectual structure of the LSCI literature.

The growth trajectory of LSCI research began with low levels of publication during the 1960s and 1970s, followed by steady and then accelerating growth in subsequent decades. Citation analyses highlighted key journals, authors and documents in this field, while ACA identified four research streams or Schools of Thought that comprise the LSCI knowledge base: transformational leadership for school improvement, instructional leadership for school improvement, shared leadership for change and school improvement, school improvement.

The review offers empirical documentation of the changing intellectual structure of the one of the key lines of inquiry that emerged in the field of educational administration over the past six decades. More broadly, the review illustrates the benefits of bibliometric analysis as a tool capable of illuminating critical features that bear upon knowledge accumulation in a line of inquiry, or a broader discipline.

The purpose of this paper is to consider the conjugate heat transfer from a flat plate involving a turbulent plane wall jet. The bottom wall of the solid block is heated by a constant heat flux.

High Reynolds number two‐equation model (κ‐ϵ) has been used for turbulence modeling. The parameters considered are the conductivity ratio of solid and fluid, the solid slab thickness and the Prandtl number. The Reynolds number considered is 15,000 because the flow becomes fully turbulent and then is independent of the Reynolds number. The range of parameters considered are: conductivity ratio = 1‐1,000, solid slab thickness = 1‐10 and Prandtl number = 0.01‐100.

The non‐dimensional bottom surface temperature is high for high‐Prandtl number fluid and vice versa. As conductivity ratio increases, it decreases whereas it increases with the increase in slab thickness. Similar trend is observed for the distribution of the interface temperature. The Nusselt number computed based on the interface temperature increases with Prandtl number. It is observed that for the range of parameters considered, local Nusselt number distribution superimposes with each other. The average heat flux at the interface has been computed and found to be equal with average heat flux at the bottom which ensures the overall heat balance.

The study of conjugate heat transfer with a turbulent wall jet will be useful for cooling of heated body.

The paper's aim is to provide information on heat transfer and flow characteristics for a jet emerging from a conical nozzle and impinging onto the cylindrical, which resembles the laser heating process, for researchers and graduate students working in the laser processing area, which can help them to improve the understanding of the laser machining process.

A numerical scheme employing the control volume approach is introduced to model the flow and heating situations. The effect of jet velocity on the heat transfer rates and skin friction around the cylindrical cavity subjected to the jet impingement was investigated.

Increasing jet velocity at nozzle exit enhances the heat transfer rates from the cavity wall and modifies the skin friction at cavity wall, which is more pronounced as the cavity depth increases to 1 mm.

The effects of nozzle cone angle on the flow structure and heat transfer characteristics were not examined, which perhaps limits the general usefulness of the findings.

Very useful information are provided for the laser gas assisted processing, which has a practical importance in machining industry.

This paper provides original information for the effects of the gas jet velocity on the cooling rates of the laser produced cavity.

In this paper, Substrate Integrated Packaging (SIP) based on thin film multilayer technology is presented. Coplanar waveguide feedthroughs calculated with 3D‐Finite Differential Methods were manufactured using a ceramic or silicon carrier, gold conductors and polyimide as dielectric. The substrate integrated packages were realized with metallic frames and lids mounted on the thin film circuitry. S‐parameter measurements show the superior quality of the feedthroughs. To verify the new packaging concept, a 10GHz and a 58GHz amplifier module were realized. From these modules the potential of the SIP‐technology is demonstrated.

In view of their significance as well as influence, this article aims to examine knowledge management (KM) mechanisms in 20 Iranian e‐government portals used to provide services to citizens.

Using the model “knowledge access, creation and transfer” (K‐ACT), a checklist was developed. This checklist was then applied to demonstrate its utility for evaluating 20 Persian‐language official e‐government portals in Iran.

The maximum score for the knowledge mechanism was 30 for knowledge creation. The mean score for KM in Iran e‐government portals was 26 per cent. This percentage indicates that e‐government portals in Iran are very poor.

Iranian e‐government portals and Iran governors must consider some features in their decisions about portal design. This area requires further work, in particular in elaborating the relationship between e‐government and KM. In addition, planning strategically with key experts to design new models for the adoption of KM in e‐government is of high importance. These experts can be computer specialists, knowledge managers, librarians, portal designers and users of portals.

This study provides an insight into the situation of KM processes in the portals of Iranian ministries.

Knowledge management (KM) is an important consideration in e‐government portals to ensure that knowledge flows efficiently between governments, individuals and organisations. A crucial aspect of e‐government portals that has not been addressed adequately is the extent to which KM mechanisms have been implemented. Specifically, the authors argue that appropriate KM mechanisms are necessary to support the access, creation and transfer of knowledge between these portals and their users. The paper aims to propose an evaluation model for this purpose by first defining the main KM mechanisms and then burrowing deeper into their constituent dimensions.

An evaluation model known as knowledge access, creation and transfer (K‐ACT) is presented which identifies three KM mechanisms for portals: knowledge access, creation and transfer. Each mechanism is characterised by a set of dimensions and sub‐dimensions representing the tools and features for supporting that mechanism. The model was derived from an analysis of the literature and validated by two independent reviewers who were trained in information science, were familiar with the objectives of the project and understood the concepts underlying KM implementation in portals. Using this model, a checklist was developed and applied to 60 e‐government portals in the Asian and North American regions to investigate the extent to which these KM mechanisms have been implemented.

The findings indicate that, on average, e‐government portals featured only about 36 per cent of the KM mechanisms described in the model. Furthermore, no significant differences in the implementation of the KM mechanisms were found between the two regions' portals. The evaluation also offered potential areas for improvement based on the K‐ACT model.

The present work has developed an evaluation model known as K‐ACT which can be used to assess KM implementation gaps in e‐government portals. This model can also be generalised to other types of portals. The evaluation also provides insights into the state of KM processes in the portals of the Asian and North American regions.

This paper aims to examine the perceived influence of knowledge management (KM) practices on the success of e-government initiatives. This paper proposes a framework depicting the overall perspective of the interactions between the environment and KM practices and associated processes in the context of e-government.

A conceptual framework was built to set the stage for empirical analysis, which included four major constituents: IT infrastructure, administrative issues, KM practices and e-government projects success. A sample of 181 civil servants completed a survey measuring the factors included in the research model. Structural equation modeling technique was used to test the model.

Results have identified IT infrastructure and administrative issues as significant predictors of e-government projects’ success, where the relationship was mediated by KM practices. The model explained 52.7 per cent of the variance in e-government success.

Governments need to enforce policies to encourage KM practices and make available the needed infrastructure for such environment. The sample size and the new Arabic survey used in the study are the major limitations, where more research is encouraged to validate the instrument and generalize the findings to different environments.

This study is the first in Jordan, and one of the few that related e-government to KM practices by proposing a comprehensive model that sums the factors related to such relationship. Its value stems from its sample of public employees and the support of its proposed framework.

In the 1990s, reverse e‐auctions were designed to be a widely used procurement tool due to the dramatic cost reduction. However, the current usage is more limited than expected, because e‐auctions do not always produce the benefits expected and firms have great difficulty in deciding the right tool to use in the negotiation. The aim of this paper is to propose a methodology for a useful utilization of the reverse e‐auctions.

This paper suggests a method based on the quality function deployment (QFD) technique to help purchasing managers to choose how and when they should use e‐auctions to buy a new product or service.

The approach proposed is structured as a tree and developed in three steps: choice between traditional negotiation and e‐auction; choice between the different typologies of e‐auction (open, secret, and in sealed envelope); and, finally, choice of the specific characteristics of the e‐auction to guarantee an optimal negotiation outcome.

As completion and validation of the method proposed, two case studies are presented and discussed.

The value of the methodology is to propose a simple but systematic approach to use the reverse e‐auctions technique. The use of a QFD‐based approach represents the originality of the method.

The purpose of this paper is to examine key emerging trends in sourcing of business services.

The paper is primarily theoretical and observational. It is based on the author's review of major academic and managerial publications, extensive interactions with industry leaders and prior experience in the industry.

Scale and scope of sourcing of business services from across firm and national boundaries is increasing. Offshore is increasingly being leveraged for higher value activities. As business services get more industrialized, activities are being split into smaller units for servicing, and a services supply chain is beginning to emerge. With sourcing becoming more strategic, risk management has become more complex and critical.

This paper provides an overview of significant emerging trends in sourcing of business services. Further complementary research – theoretical, survey or case‐study based – on each of these identified trends will help develop a more exhaustive understanding.

This paper provides business executives with a framework to view emerging changes in sourcing of business services, and to better prepare for future opportunities and challenges.

This paper takes a holistic view at sourcing of business services and identifies some key emerging trends. The review of academic, managerial and popular press publications, and insights gathered from the field have been summarized into this succinct overview. This perspective should guide further focused academic research as well as practical application in business projects.