Search results

It is a cliché that management development should be relevant to the requirements of managers. Yet this criterion so often seems to be merely part of the rhetoric of management development. The problem of relevance is more acute the more senior the manager. You can get away with formalised packaged management training for junior managers, but top managers realise that their situations are unique. In this article, we will comment on an example of developing a particular kind of senior manager, namely, potential partners for a major accountancy firm — Deloitte Haskins and Sells.

The purpose of this paper is to explore whether empirical support exists for two commonly held beliefs about the work‐home interface: women, and particularly managerial women, are prone to “super‐mother” or “super‐manage” in an effort to balance both career and child‐rearing, and these demands diminish markedly when children reach school age.

Via a survey mailed to their home, 1,103 managerial and non‐managerial men and women completed measures of work‐home and home‐work conflict, work‐related stress and strain, and reported their number of work, domestic, and leisure hours per week.

Somewhat consistent with the popular beliefs, the authors found that managerial women reported working significantly more in the home; measures of conflict and strain, however, while showing some effect were not impacted to the degree that managerial women's combined number of work and home hours per week might suggest. The authors also found that measures of hours, conflict, and strain did not diminish abruptly when children entered school, due perhaps in part to manager's increased work hours and managerial women's renewed work emphasis when children entered school. Measures of hours, conflict, and strain did show some reduction for parents of teenaged children, although they were still significantly higher than those of nonparents.

Aside from being one of the few empirical papers to examine the impact of child rearing on managerial women, our data show how these demands are not confined to working parents of preschoolers.

Reducing fuel consumption of unmanned aerial vehicles (UAVs) during transient operation is a cornerstone to achieve environment-friendly operations. The purpose of this paper is to develop a control scheme that improves the fuel economy of a turbojet in its full operating envelope.

A novel direct-thrust linear quadratic integral (LQI) approach, comprised by an optimal observer/controller satisfying specified performance parameters, is presented. The thrust estimator, based in a Wiener model, is validated with the experimental data of a micro-turbojet. Model uncertainty is characterized by analyzing variations between the identified model and measured data. The resulting uncertainty range is used to verify closed-loop stability with the circle criterion. The proposed controller provides stable responses with the specified performance in the whole operating range, even with after considering plant nonlinearities. Finally, the direct-thrust LQI is compared with a standard thrust controller to assess fuel economy and performance.

The direct-thrust LQI approach reduced the fuel consumption by 2.1090% in the most realistic scenario. The controllers were also evaluated using the environmental effect parameter (EEP) and transient-thrust-specific fuel consumption (T-TSFC). These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy. Controllers were also evaluated using the EEP and T-TSFC. These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy.

This study shows the design of an effective direct-thrust control approach that minimizes fuel consumption, ensures stable responses for the full operation range, allows isolating the thrust dynamics when designing the controller and is compatible with classical robustness and performance metrics. Finally, the study shows that a simple controller can reduce the fuel consumption of the turbojet during transient operation in scenarios that approximate realistic operating conditions.

The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process.

The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties.

The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa.

The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors.

The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.

From the 1960s onwards, students and members of the academic community on growing numbers of college and university campuses in the United States chose to confront the issue of apartheid by advocating divestment from corporations or financial institutions with any sort of presence in or relationship with South Africa. Student divestment advocates faced serious opposition from university administrators as well as opponents of institutional divestiture both at home and abroad. Despite these challenges, the academic community in the United States was one of the first arenas where anti-apartheid activism coalesced. This chapter examines the campaigns of students and educators who participated in the debate over divestment – to engage with the South African government and apartheid through dialogue and communication or to disengage completely from the country through withdrawal of financial investments. The anti-apartheid efforts of the academic community at Michigan State University, one of the first large research universities in the United States to confront the issue of apartheid and divestment at the university level and beyond, serves as a window to view academic activism against apartheid. The Southern Africa Liberation Committee (SALC), a consortium of students, faculty, and community members dedicated to aiding the liberation struggle of Southern Africa, led the efforts at Michigan State and collaborated with allies across Michigan and the United States. SALC focused most of its efforts on South Africa, though the organization also confronted the issue of South Africa's controversial occupation of South West Africa and the ongoing civil war in Angola.

Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate pitch instrumentation and classical control algorithms. This includes developing an efficient pitch angle observer with optimal estimation and evaluating controllers under uncertainty and external disturbances.

A wind tunnel test bench is designed to simulate fixed-wing aircraft dynamics. Key elements of the instrumentation commonly found in MAVs are characterized in a gyroscopic test bench. A data fusion algorithm is calibrated to match the gyroscopic test bench measurements and is then integrated into the autopilot platform. The elevator-angle to pitch-angle dynamic model is obtained experimentally. Two different control algorithms, based on model-free and model-based approaches, are designed. These controllers are analyzed in terms of parametric uncertainties due to wind speed variations and external perturbation because of sudden weight distribution changes. A series of experimental tests is performed in wind-tunnel facilities to highlight the main features of each control approach.

With regard to the instrumentation algorithms, a simple experimental methodology for the design of optimal pitch angle observer is presented and validated experimentally. In the context of the platform design and identification, the similitude among the theoretical and experimental responses shows that the platform is suitable for typical pitch control assessment. The wind tunnel experiments show that a fixed linear controller, designed using classical frequency domain concepts, is able to provide adequate responses in scenarios that approximate the operation of MAVs.

The aircraft orientation observer can be used for both pitch and roll angles. However, for simultaneousyaw angle estimation the proposed design method requires further research. The model analysis considers a wind speed range of 6-18 m/s, with a nominal operation of 12 m/s. The maximum experimentally tested reference for the pitch angle controller was 20°. Further operating conditions may require more complex control approaches (e.g. scheduling, non-linear, etc.). However, this operating range is enough for typical MAV missions.

The study shows the design of an effective pitch angle observer, based on a simple experimental approach, which achieved locally optimum estimates at the test conditions. Additionally, the instrumentation and design of a test bench for typical pitch control assessment in wind tunnel facilities is presented. Finally, the study presents the development of a simple controller that provides adequate responses in scenarios that approximate the operation of MAVs, including perturbations that resemble package delivery and parametric uncertainty due to wind speed variations.

A key challenge found in additive manufacturing is the difficulty to produce components with replicable microstructure and mechanical performance in distinct orientations. This study aims to investigate the influence of build orientation on the fracture toughness of additively manufactured AlSi10Mg specimens.

The AlSi10Mg specimens were manufactured using the selective laser melting (SLM) technology. The fracture toughness was experimentally determined (under ASTM E399-09) using C(T) specimens manufactured in different orientations. The microstructure of the specimens was examined using metallography to determine the effects of grain orientation on fracture toughness.

The fracture toughness magnitude of manufactured specimens ranged between 36 and 50 MPam, which closely matched conventional bulk material and literature values regarding AlSi10Mg components. The C(T) specimens printed in the T-L orientation yielded the highest fracture toughness. The grain orientation and fracture toughness values confirm the anisotropic nature of SLM parts where the T-L-oriented specimen obtained the highest K_IC value. A clear interaction between the melt pool boundaries and micro-slipping during the loading application was observed.

The novelty of this paper consists in elucidating the relationship between grain orientation and fracture toughness of additively manufactured AlSi10Mg specimens because of the anisotropy generated by the different melting pool boundaries and orientations in SLM. The findings show that melt pool boundaries can behave as easier pathways for cracks to propagate and subsequently reduce the fracture toughness of specimens with cracks perpendicular to the build direction.

An experimental and numerical study of thermal profiles of 316 L stainless steel during selective laser melting (SLM) was developed. This study aims to present a novel approach to determine the significance and contribution of thermal numerical modeling enhancement factors of SLM.

Surface and volumetric heat models were proposed to compare the laser interaction with the powder bed and substrate, considering the powder size, absorptance and propagation of the laser energy through the effective depth of the metal layer. The approach consists in evaluating the contribution of the thermal conductivity anisotropic enhancement factors to establish the factors that minimized the error of the predicted results vs the experimental data.

The level of confidence of the carried-out analysis is of 97.8% for the width of the melt pool and of 99.8% for the depth of the melt pool. The enhancement factors of the y and z spatial coordinates influence the most in the predicted melt pool geometry.

Nevertheless, the methodology presented in this study is not limited to 316 L stainless steel and can be applied to any metallic material used for SLM processes.

This study is focused on 316 L stainless steel, which is commonly used in SLM and is considered a durable material for high-temperature, high-corrosion and high-stress situations.

The additive manufacturing (AM) technology is a relatively new technology becoming global. The AM technology may have health benefits when compared to the conventional industrial processes, as the workers avoid extended periods of exposure present in conventional manufacturing.

This study presents a novel approach to determine the significance and contribution of thermal numerical modeling enhancement factors of SLM. It was found that the volumetric heat model and anisotropic enhancement thermal approaches used in the present research, had a good agreement with experimental results.

The purpose of this paper is to explore the effectiveness of the therapeutic community and to look at the potential changes that some patients may experience following treatment at the therapeutic communities (TC).

A thematic analysis was conducted on an e-mail sent by an ex-patient of the TC. The text was reviewed multiple times and codes were generated. Based on the data found, three themes were identified. The e-mail was sent to the patient’s primary therapist, who was asked to provide an account of the e-mail. The therapist was sent six questions created by the authors of the paper; the responses were used to compare the two perspectives.

The main findings entailed the changes the patient went through after her treatment at the TC. The patient’s account described her inability to process the adversities she had been through at the time and therefore her inability to communicate them. However, the impact the service had on the patient, according to the e-mail was evident years later. The lack of a support network during treatment at the TC and evidence of one following treatment seemed to be the key factor in the patient’s improvement.

The authors confirm that the research presented in this paper is their original work. The authors hereby acknowledge that all material included in this piece of work, that has been published or written by another person has been referenced accordingly.

The purpose of this paper is to address the need of a reengineering of the software development process in a Mexican technology services company. In general, the main risk faced by small- and medium-sized software developers (SMEs) is the inability to meet delivery times or to adjust to project requirements, whether through lack of follow-up on the critical activities of the development process or through an inadequate distribution of workloads among members of the project team.

The methodology used to carry out the reengineering of the software development process is Hammer and Champy, which consists of six stages: introduction to the current situation of the company and the need for change; identification of the business processes; selection of the business process to be redesigned; understanding of the process selected; proposal for reengineering the business process selected; and the results of the comparison between the current situation of the process and the proposed reengineering of the process through the use of Business Process Model and Notation (BPMN 2.0).

Based on the results, the paper shows the importance of the analysis and implementation of the reengineering in a software development company. It describes step-by-step how to apply the methodology of Hammer and Champy in a business process through simulated scenarios, using BPMN 2.0. By carrying out the implementation of the proposed reengineering, the company would therefore save 45.12 percent of costs, 41.17 percent of time, and a better distribution of resources, at the same time guaranteeing the satisfaction of its clients.

The study addresses the current needs of small- and medium-sized software developers, providing a step-by-step guide to the implementation of a process reengineering methodology, performing an analysis and modeling of processes in BPMN 2.0 and providing results through a simulation of the critical process, with the aim to observe the flow of activities and the significant improvements that would be achieved by implementing the reengineering proposal. This simulation schema allows business owners to observe the potential of the changes and to verify the positive impact they would have on the company before beginning to make operational changes in the organization.