Search results

Longitudinal facial cracks (LFC) are one of the major defects occurring in the continuous-casting stage of thin slab caster using funnel molds. Longitudinal cracks occur mainly owing to non-uniform cooling, varying thermal conductivity along mold length and use of high superheat during casting, improper casting powder characteristics. These defects are difficult to capture and are visible only in the final stages of a process or even at the customer end. Besides, there is a seasonality associated with this defect where defect intensity increases during the winter season. To address the issue, a model-based on data analytics is developed.

Around six-month data of steel manufacturing process is taken and around 60 data collection point is analyzed. The model uses different classification machine learning algorithms such as logistic regression, decision tree, ensemble methods of a decision tree, support vector machine and Naïve Bays (for different cut off level) to investigate data.

Proposed research framework shows that most of models give good results between cut off level 0.6–0.8 and random forest, gradient boosting for decision trees and support vector machine model performs better compared to other model.

Based on predictions of model steel manufacturing companies can identify the optimal operating range where this defect can be reduced.

An analytical approach to identify LFC defects provides objective models for reduction of LFC defects. By reducing LFC defects, quality of steel can be improved.

The purpose of this paper is to present a numerical and mathematical model of a moulding process of a dry electrical transformer. Moreover, the calculated results are reported and compared with experimental measurements.

An experimental rig, for carrying out and monitoring a moulding process, has been designed and built. Two experiments were preformed. First was an isothermal experiment in which an analog liquid was used. The second experiment was a non‐isothermal one in which an epoxy resin was used. For the rig geometry, the numerical mesh, with the use of the commercial code Gambit, was built. All necessary physical properties, including viscosity, surface tension and contact angle of fluids used in the experiments were measured.

The Euler approach for modelling multiphase flow with a free surface is addressed in the presented work. Comparison of the computational results with measurements on the designed experimental rig revealed good agreement. Comparison was carried out through measurements of free surface characteristic features captured with a digital camera and through temperature measurements for the nonisothermal case. Richardson extrapolation method was successfully applied to estimate the numerical discretisation error, proving that a grid independent solution was obtained.

This paper is useful for researchers and industrialists involved in the modelling of moulding processes, giving guidance on the available mathematical models appropriate for this kind of problem. Moreover, it provides valuable information as to how to perform validation and verification procedures for such real‐life processes.

The purpose of this article is to numerically investigate the effect of casting speed on the fluid flow, solidification and inclusion motion under the influence of electromagnetic stirring (EMS) in the bloom caster mold with bifurcated submerged entry nozzle (SEN).

The electromagnetic field obtained by solving Maxwell’s equation is coupled with the fluid flow, solidification and discrete phase model using the in-house user-defined functions. An enthalpy porosity approach and Lagrangian approach are applied for the solidification analysis and non-metallic inclusions motion tracking, respectively.

Investigation shows that the casting speed and EMS significantly affect the steel flow, solidification and inclusion behavior inside the mold. Investigations are being conducted into the complex interplay between the induced flow and the SEN’s inertial impinging jet. In low and medium casting speeds, the application of EMS significantly increases the inclusion removal rate. Inclusion removal is studied for its different size and density and further effect of EMS is also reported on cluster formation and distribution of inclusion in the domain.

The model may be used to optimize the process parameter (casting speed and EMS) to improve the casting quality of steel by removing the impurities.

The effect of casting speed on the solidification and inclusion behavior under the influence of time-varying EMS in bloom caster mold with bifurcated nozzle has not been investigated yet. The findings may assist the steelmakers in improving the casting quality.

The purpose of this study is to analyse the problem of high binder content in sand mould and to solve it. Meanwhile, to increase build speed, especially for heavy casting’s sand mould with a high value in layer height, such as 2 mm in construction instead of the industry standard of 0.3 mm, line forming for three-dimensional (3D) sand mould printing is researched.

Brief introduction of 3D sand mould printing and key issues are given first. Then, this paper quantitatively analyses binder content in sand mould. Finally, to acquire sand mould with appropriate binder content and high build speed, line forming combining traditional furan no-bake sand manufacture technique is researched, as well as relevant feasible schemes and current progress.

The study shows that compared with traditional technique, binder content in sand mould produced by available 3D printing technique is too high, bad for sand mould’s properties and quality of castings, while line forming brings guaranteed binder content and improved build speed.

More experiments are needed to demonstrate quantitative analysis of binder content and to obtain flowability of moist sand, detailed structure design of nozzle and practical build speed, as well as methods of circulation of materials considering solidification time.

Line forming with higher build speed and suitable binder content means excellent properties of sand mould and castings as well, bringing obvious implication for moulds industries and manufacturing industry.

This new method could increase build speed and meanwhile guarantee binder content. Thus, its application prospect is promising.

This paper seeks to address the preparation of new compositions of hydrophobicizing liquids as release agent for press moulds in the production of plastic articles of all kinds of polymers.

Mixtures of thermo‐stable polyethers (copolymer of ethylene oxide and propylene oxide) and polyols esters/mixed esters in the presence of phenothiazine as antioxidant were prepared and tested.

All compositions were tested and compared with silicone oil polymethylsiloxane‐100 (PMS‐100). The lubricant was manually applied on a hot surface (160‐190°C) of tray of press mould, without any change in the operating cycle. The finished products were easily removed from press mould, and showed higher durability. The release agent was also checked for production of polyethylene lids by automatic moulding at 170‐200°C, and 17 lids have been obtained on one application. This is quite a good result compared with silicone oil PMS‐100, which produced only four to five lids.

Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern spectroscopy techniques.

In order to obtain compositions of optimum properties a lot of mixtures were prepared and tested. Only compositions which showed suitable properties were reported.

This paper provides detailed information on the experimental preparation of 37 compositions for hydrophobicizing mould release agents. Testing of different obtained hydrophobicizing liquids showed positive results, in production of plastic household articles, over silicone oil PMS‐100. The finished products were easily removed from press mould and prepared hydrophobicizing liquids showed higher durability than silicone oil PMS‐100. The obtained compositions are also favored from the point of view of commercial availability and ecology and can be considered as replacements for PMS‐100 release agent.

The quality of production is an essential factor for the performance measure of a system; a casting process is the same section. It is a type of metal-forming practice in which the required shape of metal is acquired by pouring molten metal into the mold cavity and allowing it to solidify. Casting is done to provide strength and rigidity to the parts of a system for bearing mechanical impacts. The purpose of this paper is to investigate the various aspects which affect the casting process in the foundry industry, in order to optimize the quality of casting, with the assumption that sufficient repair facility is always available.

The considered casting system can have many defects such as the mold shift defect, blowhole defect, defect of shrinkage and porosity, defect of inclusion, defect of cold shut and much more. The studied system can be in three states during the process, namely, good state, failed state and degraded state. The system can repair after minor failures as well as a major failure. The average failure rates of various defects of the system considered as constant and repairs follow the general time distribution. The system is analyzed with the help of the supplementary variable technique and the Laplace transformation for evaluating its various performance measures in order to improve its performance/production.

This work provides a strong understanding of the casting industry, that which failure affects the production of casting and how much. For better understanding, the results have been demonstrated with the help of graphs.

In the present paper, a mathematical model based on the casting process in manufacturing industry has been developed.

Creativity and innovation have been buzzwords of managerial discourse over the last few decades as they contribute to the long-term survival and competitiveness of firms. Given the non-linear, causally ambiguous, and intangible nature of all innovation-related phenomena, management scholars have been trying to uncover factors that contribute to creativity and innovation from multiple lenses ranging from organizational behavior at the micro-level to strategic management at the macro-level. Along with important and insightful developments in these research streams that evolved independently from one another, human resource management (HRM) research – especially from a strategic perspective – has only recently started to contribute to a better understanding of both creativity and innovation. The goal of this chapter is to review the contributions of strategic HRM research to an improved understanding of creativity at the individual-level and innovation at the firm-level. In organizing this review, the authors rely on the open innovation funnel as a metaphor to review research on both HRM practices and HRM systems that contribute to creativity and innovation. In the last section, the authors focus on more recent developments in HRM research that focus on ambidexterity – as a way for HRM to simultaneously facilitate exploration and exploitation. This chapter concludes with a discussion of future research directions.

The purpose of this paper is to provide scholars with a robust, easy-to-follow structural model for crafting compelling academic publications. Recognizing the diversity of research methodologies and genres, the paper proposes the symmetry of specificity framework as a guide to maintaining coherence, depth and relevance across different sections of an academic paper.

This paper presents a theoretical framework – “symmetry of specificity” – through an iterative approach inspired by supervision and examination of theses, writing and reviewing research papers and editorial work. The framework builds upon the established IMRAD model and uses the concept of symmetry to explain the structural elements of academic publications. Its unique contribution lies in elucidating the two-dimensional funneling process that takes place within academic writing, and providing a nuanced understanding of how to maintain balance between different sections.

The symmetry of specificity framework introduces a novel perspective on academic writing, emphasizing the concept of “symmetry in specificity”. It shows how maintaining a balance in detail and focus across different sections of a research paper can significantly enhance its coherence and relevance. By elucidating the interaction between theory and data in research writing, it provides valuable insights into the nuances of crafting a compelling academic paper.

While the proposed symmetry of specificity framework may not be universally applicable across all types of research, it provides a solid foundation for the development of alternate structures tailored to specific research paradigms. There is ample opportunity for future research to explore adaptations of this model for various types of academic writing, offering a fresh perspective on structuring academic publications and potentially sparking new discussions and innovations in this realm.

This framework can aid both novice and experienced scholars in structuring their research papers effectively. By offering a conceptual roadmap, it guides the writer through the complex process of academic writing, from crafting the methodology and analysis sections to articulating compelling conclusions. Thus, it serves as a useful tool in enhancing the quality and impact of research communication.

This paper presents a unique approach to structuring academic publications that goes beyond the conventional IMRAD model. By offering a theory-based structural model, it contributes to an underexplored area in academic writing and opens up new avenues for pedagogy and practice in research communication.

The paper aims to investigate the comfort-related performances of an innovative solar shading solution based on a new composite patented material that consists of a cement-based matrix coupled with a stretchable three-dimensional textile. The paper’s aim is, through a performance-based generative design approach, to develop a high-performance static shading system able to guarantee adequate daylit spaces, a connection with the outdoors and a glare-free environment in the view of a holistic and occupant-centric daylight assessment.

The paper describes the design and simulation process of a complex static shading system for digital manufacturing purposes. Initially, the optical material properties were characterized to calibrate radiance-based simulations. The developed models were then implemented in a multi-objective genetic optimization algorithm to improve the shading geometries, and their performance was assessed and compared with traditional external louvres and overhangs.

The system developed demonstrates, for a reference office space located in Milan (Italy), the potential of increasing useful daylight illuminance by 35% with a reduced glare of up to 70%–80% while providing better uniformity and connection with the outdoors as a result of a topological optimization of the shape and position of the openings.

The paper presents the innovative nature of a new composite material that, coupled with the proposed performance-based optimization process, enables the fabrication of optimized shading/cladding surfaces with complex geometries whose formability does not require ad hoc formworks, making the process fast and economic.

One of the primary problems in the production of cement testing cubes is inconsistency in quality due to skill differences between operators and low repeatability in human performance of identical operations. To eliminate this problem and to enhance productivity, a state‐of‐the‐art robot workcell system, which utilized a multitasking control strategy and tool changer and sensor technology to automatically produce cement testing cubes, was designed and integrated. A comparative analysis of compressive strength values of specimens made by human operators and robots indicated that the specimens made by the robot workcell system had lower variation than the human made ones. This study not only demonstrates that robot workcells are flexible and robust enough to be used in cement testing cube production, but also suggests that revision of American Society of Testing Methods (ASTM) procedures to facilitate implementation of high technology in the materials testing process should be considered.