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A class of flux‐splitting explicit second‐order finite difference schemes is set up. An ‘optimal’ scheme is defined for 1‐D flows and applied to 2‐D flows with CFL being able to reach 2. The results obtained show that this ‘optimal’ scheme is well adapted to the unsteady flows.

To investigate the feasibility of a novel scheme of high‐efficiency induction heater for nonmagnetic metal billets which use 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 SC coil configuration, a numerical model, based on an equivalent electric network with temperature‐dependent parameters, is developed.

A substantial independence of the shape of the temperature profile on the angular velocity and the value of the uniform magnetic field applied, is observed. A strong temperature gradient is observed in the radial direction in the proximity of the penetration front and in the axial direction at the top and bottom surface of the billet. Small temperature gradient was observed in the central part of the billet.

The reported temperature profile is inadequate for an actual extrusion process which is desired to happen at a constant temperature. The appropriate profile along the billet length can be achieved by a suitable axial shaping of the magnetic field, through the optimization of the coil layout, whereas the undesired radial gradient can be reduced by interspacing the rotation with temperature smoothing intervals.

The investigation of the profile of applied magnetic field and the heating procedure which allow to achieve the distribution of temperature suitable for the extrusion process can be carried out by using the present model.

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

The purpose of the present paper is to develop a new technology for producing magnesium alloy twin-rib aircraft brackets by the forging method.

An overall description of magnesium alloys is given, with particular emphasis placed on magnesium wrought alloys that are used in the aircraft industry. Methods for producing ribbed brackets are discussed and the location of these parts in aircraft structure is described. The forging process for producing AZ31 magnesium alloy twin-rib brackets was modelled numerically, and selected results of the simulations performed are presented. The simulation results were then verified under laboratory conditions using a three-slide forging press equipped with three movable working tools. It was assumed that the use of this machine would allow for obtaining twin-rib aircraft brackets with improved both functional and strength properties compared to the production methods used so far.

The results demonstrate that the method developed by the present authors permits the production of twin-rib brackets. Positive theoretical results and preliminary experimental results prove that it is justified that the research on magnesium alloys used in the aircraft industry be continued.

The production of twin-rib aircraft brackets from magnesium alloys by the technology developed by the present authors would lead to enhanced product quality with simultaneous reduction in production costs (reduced labour costs and material consumption as well as increased process efficiency). At present, magnesium alloy aircraft parts, mainly obtained from semi-finished products imported to Poland, are produced by casting and machining methods. They exhibit, however, much worse properties than elements produced by metal forming methods. In addition to that, the application of machining in the production of these part leads to higher production costs.

The originality of this study stems from the presentation of an innovative metal forming technology for producing twin-rib brackets. This method is unique on a global scale, and its basic assumptions have been granted patent protection. Also, the originality of the study stems from the fact that brackets are made from magnesium alloys, as these light metals are considered the future of structural materials used in the aircraft industry. Given the above, the research on developing the technology for producing parts made from these alloys using a three-slide press is justified.

Marketing and brand managers are under more pressure than ever before to demonstrate the impact of the managers' strategies and actions on company value, especially in an emerging market. In this context, the authors investigate the relationship between brand equity and company performance using the rankings of most valued brands from Brand Finance (BF), Brand Analytics (BZ) and Interbrand (IB).

The authors use used a panel from the period between 1990 and 2018 (29 years), consisting of a sample of 689 companies with shares traded in an emerging market representing 7,970 observations with unbalanced data. The authors applied a dynamic Differences-in-Differences Ordinary Last Squares (DID OLS) method.

The main finding of this study is that brands ranked as valuable significantly increased the brands' companies' intangible assets, return on assets, free cash flow (FCF) and market value.

The present study helps brand and marketing managers show to chief executive officers (CEOs) and shareholders the importance of brand development. In addition, valuable brand companies of an emerging market may represent an interesting opportunity for market investors.

This study contributes to the marketing literature, addressing the fields of marketing and finance, by analyzing the performance of companies separately over a long period, with different metrics, an unconventional model in the marketing area and different rankings of valuable brand names.

The purpose of this paper is to first elaborate on the notion of a learning environment based on an empirical study of care work. Second, to explore how aspects of a learning environment may differ between and within units in the same organization, and how to understand and explain such differences.

The study was based on a multiple case‐study design including four departments within two care units. Data were collected through direct observation of working conditions and work practices as well as semi‐structured interviews with all care‐workers within the two units (29 persons), and with the head and deputy head for each of the two units.

It was possible to distinguish between two qualitatively different patterns of working conditions and practices within the four teams. These patterns of practice were interpreted as representing an enabling and a constraining type of learning environment as these concepts were defined in this study. The evidence suggests that the emergence of an enabling learning environment was an outcome of a dynamic interplay between a number of factors that had the character of a virtuous circle.

The article adds to previous research through a distinction between two types of learning environment (enabling and constraining), and by linking these two types of learning environment to different conceptions of learning and to different working conditions and practices.

The association between social media and jealousy is an aspect of the dark side of social media that has garnered significant attention in the past decade. However, the understanding of this association is fragmented and needs to be assimilated to provide scholars with an overview of the current boundaries of knowledge in this area. This systematic literature review (SLR) aims to fulfill this need.

The authors undertake an SLR to assimilate the current knowledge regarding the association between social media and jealousy, and they examine the phenomenon of social media-induced jealousy (SoMJ). Forty-five empirical studies are curated and analyzed using stringent protocols to elucidate the existing research profile and thematic research areas.

The research themes emerging from the SLR are (1) the need for a theoretical and methodological grounding of the concept, (2) the sociodemographic differences in SoMJ experiences, (3) the antecedents of SoMJ (individual, partner, rival and platform affordances) and (4) the positive and negative consequences of SoMJ. Conceptual and methodological improvements are needed to undertake a temporal and cross-cultural investigation of factors that may affect SoMJ and acceptable thresholds for social media behavior across different user cohorts. This study also identifies the need to expand current research boundaries by developing new methodologies and focusing on under-investigated variables.

The study may assist in the development of practical measures to raise awareness about the adverse consequences of SoMJ, such as intimate partner violence and cyberstalking.

The purpose of this paper is to examine the mediating role of the attitudes toward seeking professional psychological help between career adaptability and active job search behavior of older workers in South Korea.

From a review of related literature, six study hypotheses were developed to test the structural relationship between the variables.

This study identified that attitudes toward seeking professional psychological help mediated the relationship between career adaptability, the value of career coaching and active job search behavior.

A successful job search requires the use of substantial self-control and self-regulation skills, and there can be effective training in all these skills of self-disciplining when older workers can find a high level of value from career coaching programs.

Despite the growing popularity of career support programs, the quality of career coaching programs and participants’ perceived value toward them are critical to illicit positive outcomes of such programs. This study supports this premise by revealing a structural relationship between career adaptability, perceived value of career coaching, attitudes toward seeking professional career help and active job search behavior.

The purpose of this paper is to focus on the professional activity development of prop makers. These professionals are responsible for creating a huge variety of objects for the stage, ranging from furniture and soft furnishings to weapons, statues, jewelry and animated models. A feature of the work is to create objects that are new almost every time. In Western Switzerland, there is neither initial training nor continuing education for the profession of prop maker. Therefore the aim of this study is to better understand the professional practices and informal learning of prop makers at the Grand Théâtre de Genève.

Given their interest in the details of how work is learned and carried out, the authors used ethnographic methods to study the prop makers' working practices. These methods place an emphasis on the detailed observation of practices through intensive, long-term involvement. The fieldwork began in November 2005 and ended in May 2007. This period was organized into three phases articulating direct observation and participant observation. The data were processed according to the methodology of grounded theory. Theoretical sensitivity came from a number of sources; however, French-speaking ergonomics, and particularly the course-of-action theoretical framework, have largely determined our conception of activity and workplace learning.

The results allowed the authors to identify the core of a substantive theory of prop makers' activity and self-construction. Three components formed the core of this theory: conservation, invention, and distribution (CID). These three components are essential to understanding how prop makers are able to achieve, maintain and develop professional expertise both individually and collectively in the near total absence of initial and ongoing training and in a context of constant demand for high technical performance.

Despite the limitations of this study and the need for caution, the study seems to have two main implications. First, it leads to the reaxamination of the concept of informal learning and to assume the self-constructive dimension of activity. Second, it encourages studies to question the triple developmental process: technical, individual, and collective. Further studies are needed to better understand the triple process of individuation (technical, individual and collective) that operates in work situations and to test the heuristic power of this notion to account for learning and development in the workplace.

The originality of this work is to address the issue of professional development in relation to the work of Simondon Gilbert on technical invention and his theory of individuation.

This paper aims to investigate the effects on material properties of layer-by-layer application of pressure during fabrication of polymeric parts by additive manufacturing (AM). Although AM, also known popularly as 3D printing, has set a new standard for ease of use and minimal restraint on geometric complexity, the mechanical part properties do not generally compare with conventional manufacturing processes. Contrary to other types of polymer processing, AM systems do not normally use (in-process) pressure during part consolidation.

Tensile specimens were produced in Somos 201 using conventional laser sintering (LS) and selective laser printing (SLP) – a process under development in the UK, which incorporates the use of pressure to assist layer consolidation.

Mechanical testing demonstrated the potential to additively manufacture parts with significantly improved microstructure and mechanical properties which match or exceed conventional processing. For example, the average elongation at break and ultimate tensile strength of a conventionally laser-sintered thermoplastic elastomer (Somos 201) increased from 136 ± 28 per cent and 4.9 ± 0.4 MPa, to 513 ± 35 per cent and 10.4 ± 0.4 MPa, respectively, when each layer was fused with in-process application of pressure (126 ± 9 kPa) by SLP.

These results are based on relatively small sample size, but despite this, the trends observed are of significant importance to the elimination of voids and porosity in polymeric parts.

Layerwise application of pressure should be investigated further for defect elimination in AM.

This is the first study on the effects of layerwise application of pressure in combination with area-wide fusing.

The paper aims to deal with the induction heating of metal billets rotating in a DC magnetic field.

The induced power distributions are analysed and the main heating parameters are estimated with reference to an infinitely long Al billet 200 mm diameter. The paper refers to the activity developed in the frame of a National Italian Project carried out by research groups of the Universities of Bologna, Padua and Roma “La Sapienza.”

The main process parameters have been evaluated for the heating up to 500°C of an Al billet 200 mm diameter.

This innovative technology appears to be very promising for improving the efficiency of the through heating of high‐conductivity metals (e.g. copper, aluminum) before hot working, by using superconducting magnets.

The paper analyses the induction heating of a infinitely long billet rotating in a uniform DC magnetic field.