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PREP - Pragmatic Research On Educational Practice
Get PDFWe investigate a concept called PREP – Pragmatic Research on Educational Practice, with the goal of engaging engineering educators in studying, documenting and sharing their initiatives to improve teaching practices. This concept is compared to other methodologies where the researcher and educational practitioner sometimes coincide. The study is based on a pilot, with six participants following the PREP program for threemonths, which we study autoethnographically. We also carried out a focus group discussion (n=12) to investigate to what extent university teachers regard the ideas from the PREP program as helpful for studying educational activities and sharing what they do and find
Designing work in production: Balancing top-down job design and bottom-up job crafting
Get PDFWith increasing global competition and technological progress, production companies face new demands to stay competitive and innovative. To achieve this, it\u27s essential to better involve the production personnel. New ways of shaping production jobs are therefore necessary, so that individual employees have a chance to grow, develop, and challenge themselves to reach motivation and continuous learning. When development in production is rapid, operators need to be innovative and involved in finding new solutions. Job design has traditionally been viewed as a top-down activity, where employees have little influence and are merely expected to fulfil their designated tasks. A contrasting bottom-up activity is job crafting, where individuals reshape their work to better meet their individual needs. The strictness of the imposed job design can vary, through clear or vague job descriptions and differing levels of opportunities for job crafting. It is not obvious what the optimal balance is between the two to reach a sustainable work situation where individual needs are met while also upholding performance and meeting company goals.This thesis aims to explore the balancing between top-down job design and bottom-up job crafting in the context of operational jobs in production. In doing so, two papers are included. The first paper is an interview study on job crafting practices of front-line managers in production, while the second paper focuses on implementing a work design intervention for increased organizational learning in production teams. Findings suggest that front-line managers have vague job descriptions and role overload, leading to a work situation where both proactive and reactive job crafting practices are extensively used. In contrast, operators in production teams instead have very strict job descriptions with limited autonomy and learning opportunities, and little opportunity to shape and redesign their own work.Achieving simultaneous control and flexibility by finding a balance between top-down job design and bottom-up job crafting is a challenging task but holds the potential for combining increased performance and competitiveness for the organization with sustainable work conditions for the individual. An improved work design can aid in meeting increased demands for learning and motivation, leading to enhanced innovation and adaptability in the production industry
Breakdown characteristics of nitrogen at different pressures in alternating non-uniform electric fields
No full textACbreakdown characteristics of nitrogen at different pressures in electric fields with different degrees of non-uniformity provided by a sphere-plane electrode system have been investigated. It is found that the measured breakdown voltages obey Paschen’s law at the values of the field factor (the ration of the maximum field strength between electrodes to the average field strength) below∼2. Deviations start to appear and increase gradually if the field factor increases above this threshold. Respectively, the dependence of the breakdown voltageUb on the product of pressure p and gap distance d changes from been linearUb∼p
7d to a more complex relationship of typeUb∼p
7ln(d). It is found that the maximum field strength corresponding to the breakdown increases with increasing gas pressure and decreasing electrode radius but it is independent on the gap distance. The breakdown voltagespredicted by the streamer criterion agree well with the experimental data. The results obtained for nitrogen were compared with the breakdown characteristics of air and it was found that at the values of the field factor below 9, the breakdown strength of nitrogen was higher than that of ambient air
The numerical simulation of standard concrete tests and steel reinforcement using force flux peridynamics
Get PDFPeridynamics is a numerical particle-based solid mechanics method that enables the simulation of brittle and quasi-brittle materials, as well as ductile materials. It allows cracking to appear spontaneously in the arms joining the particles and can therefore be used to simulate progressive fracture. In this article, we apply our version of peridynamics, which we call force flux peridynamics, to the simulation of concrete where the appearance of cracks plays an important role in the global mechanical properties. It is not difficult to modify the material parameters in peridynamics to achieve a given tensile strength or a given compressive strength. However, it is much more difficult to choose parameters which will model all the strength parameters of a material within the same model. When concrete fails in compression it may split or spall showing a complex relationship between compressive and tensile failure. We therefore set ourselves the simple task of producing a single peridynamics model which can predict the stiffness and strength behavior of concrete in standard compression and tension tests for which we chose the American Society for Testing and Materials standards for the cylinder compression test, the split cylinder test, and the modulus of rupture test. A parameter sensitivity study was performed based on the cylinder compression test to tune the key peridynamics parameters that determine the global material behavior. The compressive and tensile strengths were then determined from the combined simulation data. While the fracture modes, crack branching pattern and also the stress–strain curve show promising results, the maximum tensile strength was found to be significantly larger than physical experiments suggest. This is probably due to imperfections within real concrete at the interface between aggregate particles and cement paste and it shows that the detailed numerical modeling of the failure of concrete is highly complex with a large number of unknown material parameters
Wind-assisted, electric, and pure wind propulsion - the path towards zero-emission RoRo ships
Get PDFElectrical and wind propulsion, together with energy stored in batteries and renewable energies harnessed onboard, can lead the way towards zero-emission ships. This study compares wind propulsion solutions and battery storage possibilities for a RoRo ship operating in the Baltic Sea. The ship energy systems simulation model ShipCLEAN is used to predict the performance of the zero-emission ship in real-life operating conditions. The study showcases how ships can be transferred from a conventional, diesel-powered to a zero-emission ship. For the zero-emission ship, all energy needed for auxiliaries and propulsion is taken from renewable sources onboard or from batteries. Challenges and opportunities, as well as necessary adaptions of the route and logistics, are discussed. Results of the study present which wind propulsion technology is the most suitable for the example RoRo ship, and how the installation of suitably sized battery packs for zero-emission operation affects the cargo capacity of the ship
LES/FGM investigation of ignition and flame structure in a gasoline partially premixed combustion engine
Get PDFThis paper presents a joint numerical and experimental study of the ignition process and flame structures in a gasoline partially premixed combustion (PPC) engine. The numerical simulation is based on a five-dimension Flamelet-Generated Manifold (5D-FGM) tabulation approach and large eddy simulation (LES). The spray and combustion process in an optical PPC engine fueled with a primary reference fuel (70% iso-octane, 30% n-heptane by volume) are investigated using the combustion model along with laser diagnostic experiments. Different combustion modes, as well as the dominant chemical species and elementary reactions involved in the PPC engines, are identified and visualized using Chemical Explosive Mode Analysis (CEMA). The results from the LES-FGM model agree well with the experiments regarding the onset of ignition, peak heat release rate and in-cylinder pressure. The LES-FGM model performs even better than a finite-rate chemistry model that integrates the full-set of chemical kinetic mechanism in the simulation, given that the FGM model is computationally more efficient. The results show that the ignition mode plays a dominant role in the entire combustion process. The diffusion flame mode is identified in a thin layer between the ultra fuel-lean unburned mixture and the hot burned gas region that contains combustion intermediates such as CO. The diffusion flame mode contributes to a maximum of 27% of the total heat release in the later stage of combustion, and it becomes vital for the oxidation of relatively fuel-lean mixtures
Sustainable business models and innovation strategies to realize them: A review of 87 empirical cases
Get PDFThe importance of developing sustainable business models has recently received increased interest in society and among scholars. While firms attempt to innovate their business models towards sustainability or create new businesses to address sustainability issues, it becomes clear that there is no one-size-fits-all model when it comes to sustainable business models. Consequently, firms often struggle to identify, develop, and implement sustainable business models that suit them. This paper aims to address this problem by drawing on the wealth of recently published empirical studies and reviewing 87 cases where firms have performed business model innovation to achieve sustainable business models. Four main sustainable business models are identified that have been achieved through different business model innovation strategies. The review contributes to managers by offering a portfolio of strategies to achieve sustainable business models and to research by clarifying the relation between the business model innovation and sustainable business model concepts
Bi-objective optimization of the tactical allocation of job types to machines: mathematical modeling, theoretical analysis, and numerical tests
Get PDFWe introduce a tactical resource allocation model for a large aerospace engine system manufacturer aimed at long-term production planning. Our model identifies the routings a product takes through the factory, and which machines should be qualified for a balanced resource loading, to reduce product lead times. We prove some important mathematical properties of the model that are used to develop a heuristic providing a good initial feasible solution. We propose a tailored approach for our class of problems combining two well-known criterion space search algorithms, the bi-directional ε-constraint method and the augmented weighted Tchebycheff method. A computational investigation comparing solution times for several solution methods is presented for 60 numerical\ua0instances
Regulation of functional groups enable the metal-free PDINH/GO advisable antibacterial photocatalytic therapy
No full textN-type organic semiconductor perylene-3,4,9,10-tetracarboxylic acid diimide (PDINH) are well-investigated photocatalyst. However, the photocatalytic potential for antibacterial therapy has been underexplored owing to the insufficient light absorption and rapid recombination of light-induced carriers. Herein, functional group-regulated is introduced by recrystallizing PDINH on the surface of GO in situ, endowing the PDINH/GO with enhanced photocatalytic properties, which harvest light energy across the full spectrum form ultraviolet to near-infrared. Simultaneously, the enhanced photogenerated carriers can activate Lewis base of GO to form an amide bond on the interface between bacteria and material, exhibiting high-efficient and steady bacteria trap. Compared with PDINH, both in vitro and in vivo all demonstrated PDINH/GO possess excellent antibacterial effect. In addition, as a non-metallic semiconductor, PDINH/GO shows capacity of enhancing epidermal cells proliferation and migration, resulting in successful infectious wound regeneration in mice and the side effects in vivo are negligible. Such the integration of wide-spectrum response, high efficiency of carrier separation, intentional bacterial capture and accelerated would healing of PDINH/GO not only enables an effective antibacterial therapy but also contributes to a successful example to activate nanomaterials by regulation of functional groups
Actor roles and public–private interaction in transitioning networks: the case of geofencing for urban freight transport in Sweden
Get PDFPurpose – This paper aims to investigate actor roles and public–private interactions in networks. Role dynamics are explored in two settings: the current development network and the future implementation network to which actors are transitioning.Design/methodology/approach – The paper builds on the industrial marketing and purchasing approach to business markets and uses a qualitative methodology. A case study of a network developing geofencing applications in the context of sustainable transport was used. The main source of data was interviews with 26 respondents from public and private organizations.Findings – Roles in development and implementation of geofencing are identified, where private and public actors may take on one or several roles in the developing setting. When transitioning to the implementation setting, the expectations of public actors vary and there is ambiguity over their roles, which range from active to inactive. This detailed empirical case study shows the complexity of multi-actor involvement when developing digital technology for the transport system.Research limitations/implications – The study highlights the transition from firm-centric innovation to network-centric innovation and its implications on actor roles.Practical implications – Organizations participating in public–private innovation networks need to be aware of the multiple roles public organizations play and the complexities they face.Originality/value – The paper explores role dynamics within and between the development and implementation settings of geofencing. Within the current development setting, roles are identified at different organizational levels with limited change in role dynamics. When transitioning to a new setting, actors’ role dynamics may range from “limited” to “path-breaking.” In future settings, actors enter and exit networks and their roles may change dramaticall