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The purpose of this paper is to investigate the impact of employee homogeneity on the financial performance of minority business enterprises (MBEs). It is widely postulated that MBEs tend to hire minorities that resemble the ethnicity of the founder(s) and that this is beneficial by helping to decrease minority unemployment rates as well as providing new opportunities to minorities that they might not otherwise receive at White-owned firms.

The study used hierarchical linear regression on archival data of 271 MBEs to determine if employee homogeneity will be a factor in understanding their financial performance. The authors also conducted exploratory interviews with a convenience sample of MBEs to gain insight into the concept of employee homophily.

The research uncovered that as homogeneity increases, MBE financial performance decreases, and this effect is more pronounced the longer the MBE is in business.

The data set is cross-sectional in nature and lack the perspective and clarity of time. The paper only contains a small set of exploratory interviews. The most significant implication from the study is that a lack of diversity decreases the long-term financial viability of MBEs which is to counter mainstream arguments that speak only to the positive aspects of MBEs hiring their own.

The research builds on the scant literature on the impact of diversity within MBEs. It also provides guidance to MBEs by suggesting they be strategic in diversifying their employee base in order to improve performance.

Most multi-level studies are cross-sectional and focus on a certain point in time, though various changes within levels may occur over time. This chapter presents a statistical method for assessing whether the degree of interdependency within a group has changed over time, using the intraclass correlation coefficient (ICC) as an indicator of the degree of homogeneity within the groups. It then shows how to apply this method using the SAS MIXED procedure. The problem was motivated by a study in which 120 subjects were divided into 40 groups of three. In a portion of the study, collective efficacy was the dependent variable measured for each subject under four different conditions (two levels of task interdependence at two points in time). ICC was used as a measure of group homogeneity with respect to collective efficacy, and the problem was how to compare the dependent ICCs associated with the different conditions.

The purpose of this paper is to analyse the transient effects in a functionally graded photo-thermoelastic (TE) medium with gravity and rotation by considering two generalised TE theories: Lord–Shulman (LS) and Green–Lindsay (GL). The governing equations are derived in rectangular Cartesian coordinates for a two dimensional problem.

All the physical properties of the semiconductor are supposed to vary exponentially with distance. The analytical solution is procured by employing normal mode technique on the resulting non-dimensional coupled field equations with appropriate boundary conditions.

For the mechanically loaded thermally insulated surface, normal displacement, stress components, temperature distribution and carrier density are calculated numerically with the help of MATLAB software for a silicon semiconductor and displayed graphically. Some particular cases of interest have also been deduced from the present results.

The effects of rotation and non-homogeneity on the different physical fields are investigated on the basis of analytical and numerical results. Comparisons are made with the results predicted by GL theory in the presence and absence of gravity for different values of time. Comparisons are also made between the three theories in the presence of rotation, gravity and in-homogeneity. Such problems are very important in many dynamical systems.

In this chapter, we discuss Cohen and Doveh's (this volume) proposed protocol for testing differences in intra-class correlation coefficients (ICCs). We believe that there are many research questions that can be addressed by this procedure. We provide several potential examples of using this procedure at the individual, group, and organizational/society levels of analysis. We do, however, raise concerns about interpreting the ICC as an index of within-group homogeneity.

The purpose of this paper is first, to gain insight into how the European member states have addressed the concept of sustainability in their building regulatory frameworks; and second, to gain insight in the effects of harmonization attempts of these frameworks by the European Commission (EC).

Data on the member states' building regulatory regimes were gathered using a survey questionnaire. The survey questionnaire addressed over 60 different aspects of sustainable construction that may, in various ways, be regulated by the member states.

The data obtained show mixed results. Some aspects of sustainable construction show far‐reaching homogeneity, whilst others do not. It appears that current EC directives have a positive effect on homogeneity of sustainable construction regulation throughout Europe. However, this does not provide a firm base to advise more directives, as these often appear a too resource‐intensive tool to achieve sustainable construction in a timely fashion. Additional and complementary approaches to such directives are proposed.

The paper presents an overview of how European member states have addressed various aspects of sustainable construction in their construction regulatory frameworks. This provides valuable insights for further studies on regulatory change, regulatory convergence and divergence, and policy outcomes related to sustainable construction in the European Union. Also, the study presents a number of approaches to achieve homogeneity that may complement earlier approaches taken by the EC.

To analyse the heating process of an aluminum billet rotating in a static magnetic field produced by superconducting coils.

The idea is to force the billet to rotate in a static magnetic field produced by a DC superconducting magnet. Since, a static superconducting magnet has no losses, the efficiency of the system is the efficiency of the motor used. In order to evaluate the temperature distribution arising from the field profile produced by a given coil configuration, a numerical model, based on an equivalent electric network with temperature‐dependent parameters, is used.

The main heating parameters, i.e. heating time, total power injected and temperature difference, are evaluated for different values of angular velocity and magnetic field. The field profile suitable to meet the specifics of an industrial heating process in terms of temperature homogeneity and heating time is determined. Starting form this profile the layout of the magnet is arrived at and some considerations on the operating condition of the superconducting windings are reported.

The mechanical stress in the billet due to weight, centrifugal effects, applied torque and resonance is examined by taking into account the weakening of the material properties with the increase of temperature and the practical limits of the heating process are evaluated.

DC induction heating of aluminum billet using superconducting magnets can be done fulfilling the specifics of the industrial processes.

A high‐efficiency induction heater for aluminum billets using superconducting coils in a novel scheme is investigated.

The purpose of this paper is to discuss the role of Markovian transitions related to the economic convergence among countries. Thus, the paper aims to develop an overview of several classical approaches, including an analysis of fallacies exposed through the literature.

The number of modes in the distribution of the RGDPL for 100 countries in the period from 1986 to 2000 is calculated. Next, the results obtained from the relevant transition matrices are discussed and the existence of twin peaks in the distribution of income is analyzed. Finally, the adequacy of both Markovian and (time) homogeneity hypotheses in connection with the stochastic process that underlies income distribution is studied.

The results across the period 1986‐2000 show the evolution of countries into convergence clubs, instead of the existence of economic convergence.

The paper discusses two important issues on the convergence hypothesis. First, the discretization process really matters. If quartiles or quintiles are used the ergodic distribution does not show twin peaks because the process shows an equiprobabilistic ergodic (stationary) distribution in the long term. Second, the twin peaks results need a Markov (time) homogeneous chain as a model for the underlying income process, and then Chapman‐Kolmogorov's equation must be satisfied. However, the paper finds empirical evidences of failure in such an argument.

Previous studies of worker-owned firms claimed that participatory democracy only thrives in small, homogeneous groups. This article focuses on a successful 30-year-old worker-owned company with more than 200 employees to explain how broad and deep democratic control, a large workforce, and member diversity are brought together. Drawing attention to its combination of training, infrastructure, compensation for management functions, and workplace culture, I argue that an equitable distribution of power and resources does not require hierarchical management, friendship relations, size limits, or member homogeneity. The article highlights the need for greater scholarly attention to worker ownership possibilities for the current multiracial and multicultural working population.

The cooling process of polymer components fabricated by selective laser sintering (SLS) plays a vital role in determining the crystallinity, density and the resultant properties of the produced parts. However, the control and optimization of the cooling process remains challenging. The purpose of this paper is to therefore investigate the cooling process of the SLS fabricated polyamide 12 (PA12) components through simulations. This work provides necessary fundamental insights into the possibilities for optimization and control of this cooling process for achieving desired properties.

The thermal properties of the PA12 powder and SLS fabricated PA12 components including density, specific heat and thermal conductivity were first determined experimentally. Then, the finite element method was used to optimize a container (a cuboid aluminum box where PA12 parts are built by the SLS) geometry in which the SLS parts can cool down in a controlled manner. Also, the cooling parameters required for maximum temperature homogeneity and minimum cooling time were determined.

Two different approximations in the finite element (FE) model were used and compared. It was found that the approximation which considers powder as a solid medium with porous material properties gives better results as compared to the approximation which treats powder as a collection of air and particles with solid material properties. The results also showed that the geometry of the containers has an important influence on the cooling process of the SLS fabricated PA12 components regarding temperature homogeneity and cooling time required. A container with a small width, long length and high height tends to result in a more homogenous temperature distribution during the cooling process.

Thermal constants of PA12 powder and parts were accurately determined as a starting point for numerical simulations. The FE model developed in this work provides useful and necessary information for the optimization and control of the cooling process of the SLS fabricated PA12 components and can thus be used for ensuring high-quality products with desired component properties.

With heterogeneous findings dominating the growth and natural resources relations, there is a need to explain the variances in Africa's growth process as induced by robust measures of factor endowments. This study used a comprehensive set of data from the updated database of the World Bank to capture the heterogeneous dimensions of natural resource endowments on growth with a particular focus on establishing complementary evidence on the resource curse hypothesis in energy and environmental economics literature in Africa. These comprehensive data on oil rent, coal rent and forest rent could provide new and insightful evidence on obscure relations on the subject matter.

This paper considers the panel vector error correction model (PVECM) procedure to explain changes in economic growth outcomes as induced by oil rent, coal rent and forest rent. The consideration of the PVECM was premised on the panel unit root process that returns series that were cointegrated at the first-order differentials.

The paper found positive relations between oil rent, coal rent and economic development in Africa. Forest rent, on the other hand, is inversely related to economic growth in Africa. Trade and human capital are positively related to economic growth in Africa, while population growth is negatively associated with economic growth in Africa.

Short-run policies should be tailored towards the stability of fiscal expenditure such that the objective of fiscal policy, which is to maintain the condition of full employment and economic stability and stabilise the rate of growth, can be optimised and sustained. By this, the resource curse will be averted and productive capacity will increase, leading to sustainable growth and development in Africa, where conditions for growth and development remain inadequately met.

The originality of this paper can be viewed from the strength of its arguments and methods adopted to address the questions raised in this paper. This study further illuminated age-long obscure relations in the literature of natural resource endowment and economic growth by taking a disaggregated approach to the component-by-component analysis of natural resources factors (the oil rent, coal rent and forest rent) and their corresponding influence on economic growth in Africa. This pattern remains underexplored mainly in previous literature on the subject. Many African countries are blessed with an abundance of these different natural resources in varying proportions. The misuse and mismanagement of these resources along various dimensions have been the core of the inclination towards the resource curse hypothesis in Africa. Knowing how growth conditions respond to changes in the depth of forest resources, oil resources and coal resources could be useful pointers in Africa's overall energy use and management. This study contributed to the literature on natural resource-induced growth dynamics by offering a generalisable conclusion as to why natural resource-abundance economies are prone to poor economic performance. This study further asks if mineral deposits are a source or reflection of ill growth and underdevelopment in African countries.