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Open Access
Article
Publication date: 27 June 2023

Farid Salari, Paolo Bosetti and Vincenzo M. Sglavo

Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design…

Abstract

Purpose

Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design file is sliced to generate G-codes before printing. This paper aims to study the effect of key input parameters for slicer software on the final properties of printed products.

Design/methodology/approach

The one factor at a time (OFAT) methodology is used to investigate the impact of selected parameters on the final properties of printed specimens, and the causes for the variations in outcomes of each variable are discussed.

Findings

Finer aggregates can generate a more compact layer, resulting in a denser product with higher strength. Fluid pressure is directly determined by voxel rate (rV); however, high pressures enable better fluid penetration control for fortified products; for extreme rVs, residual voids in the interfaces between successive layers and single-line primitives impair mechanical strength. It was understood that printhead movement along the orientation of the parts in the powder bed improved the mechanical properties.

Originality/value

The design of experiment (DOE) method assesses the influence of process parameters on various input printing variables at the same time. As the resources are limited, a fractional factorial plan is carried out on a subset of a full factorial design; hence, providing physical interpretation behind changes in each factor is difficult. OFAT aids in analyzing the effect of a change in one factor on output while all other parameters are kept constant. The results assist engineers in properly considering the influence of variable variations for future DOE designs.

Details

Rapid Prototyping Journal, vol. 29 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 17 October 2022

Qianqian Li, Bo Zhang, Tao Yang, Qingwen Dai, Wei Huang and Xiaolei Wang

The purpose of this paper is to artificially construct a functional surface with self-propulsion flow characteristics for the directional transportation of propellant in surface…

Abstract

Purpose

The purpose of this paper is to artificially construct a functional surface with self-propulsion flow characteristics for the directional transportation of propellant in surface tension tanks.

Design/methodology/approach

In this study, a method to enhance the propulsion efficiency by using functional surfaces of self-propulsion performance was proposed. Superhydrophilic wedged-groove with the superhydrophobic background was fabricated and the self-propulsion capacity was verified.

Findings

It is found that the self-propulsion capacity is related to the divergence angle of the wedged-groove in the hydrophilic area, and the velocity of the droplets on the deflector plate is the largest with the divergence angle of 4°; the temperature gradient field formed by the condensing device at the nozzle can accelerate the droplet outflow from the tank.

Originality/value

Realization of this idea provides an accurate control strategy for the complex flow process of propellant in plate surface tension tanks, which could enhance the efficiency of the tension tank significantly.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 3 no. 2
Type: Research Article
ISSN: 2633-6596

Keywords

Open Access
Article
Publication date: 29 February 2024

Guanchen Liu, Dongdong Xu, Zifu Shen, Hongjie Xu and Liang Ding

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous…

Abstract

Purpose

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Design/methodology/approach

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

Findings

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

Originality/value

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2633-6596

Keywords

Open Access
Article
Publication date: 6 March 2020

Cornelis van Dorsser and Poonam Taneja

The paper aims to present an integrated foresight framework and method to support decision-makers who are confronted with today’s complex and rapidly changing world. The method…

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Abstract

Purpose

The paper aims to present an integrated foresight framework and method to support decision-makers who are confronted with today’s complex and rapidly changing world. The method aims at reducing the degree of uncertainty by addressing the inertia or duration of unfolding trends and by placing individual trends in a broader context.

Design/methodology/approach

The paper presents a three-layered framework and method for assessing megatrends based on their inertia or duration. It suggests that if long-term trends and key future uncertainties are studied in conjunction at a meta-level and placed in a broader multi-layered framework of trends, it can result in new insights.

Findings

The application of the proposed foresight method helps to systematically place a wide range of unrelated trends and key uncertainties in the context of a broader framework of trends, thereby improving the ability to understand the inertia, direction and mutual interaction of these trends.

Research limitations/implications

The elaboration of identified trends and key uncertainties is partly case-specific and subject to interpretation. It is aimed at illustrating the potential use of the framework.

Practical implications

The paper presents a new approach that may, by itself or in combination with existing foresight methods, offer new means for anticipating future developments.

Social implications

The use of the proposed framework has potential to provide better insight in the complexity of today’s rapid-changing world and the major transitions taking place. It aims to result in sharper foresight by reducing epistemic uncertainty for decision-makers.

Originality/value

The paper demonstrates how megatrends, Kondratieff waves and century-long trends can be placed in an integrated framework and analysed in conjunction.

Details

foresight, vol. 22 no. 2
Type: Research Article
ISSN: 1463-6689

Keywords

Open Access
Article
Publication date: 6 June 2023

Yunjia Wang and Qianli Zhang

It is of great significance to study the influence of subgrade filling on permafrost temperature field in permafrost area for the smooth construction and safe operation of…

Abstract

Purpose

It is of great significance to study the influence of subgrade filling on permafrost temperature field in permafrost area for the smooth construction and safe operation of railway.

Design/methodology/approach

The paper builds up the model for the hydrothermal coupling calculation of permafrost using finite element software COMSOL to study how permafrost temperature field changes in the short term after subgrade filling, on which basis it proposes the method of calculation for the concave distortion of freezing front in the subgrade-covered area.

Findings

The results show that the freezing front below the subgrade center sinks due to the thermal effect of subgrade filling, which will trigger hydrothermal erosion in case of sufficient moisture inflows, leading to the thawing settlement or the cracking of the subgrade, etc. The heat output of soil will be hindered the most in case of July filling, in which case the sinking and the distortion of the freezing front is found to be the most severe, which the recovery of the permafrost temperature field, the slowest, constituting the most unfavorable working condition. The concave distortion of the freezing front in the subgrade area increases with the increase in temperature difference between the filler and ground surface, the subgrade height, the subgrade width and the volumetric thermal capacity of filler, while decreases with the increase of the thermal conductivity of filler. Therefore, the filler chose for engineering project shall be of small volumetric thermal capacity, low initial temperature and high thermal conductivity whenever possible.

Originality/value

The concave distortion of the freezing front under different working conditions at different times after filling can be calculated using the method proposed.

Details

Railway Sciences, vol. 2 no. 2
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 27 June 2023

Carla Sofia Ferreira Fernandes, João Loureiro and Fátima Alves

This paper aims to define a proposal of a theoretical–methodological framework aimed at supporting researchers in conducting studies on the topic of environmental mobility.

Abstract

Purpose

This paper aims to define a proposal of a theoretical–methodological framework aimed at supporting researchers in conducting studies on the topic of environmental mobility.

Design/methodology/approach

The complexity of environmental change and the frequent subsequent human mobility raises challenges in the research process. The variety of theoretical and methodological approaches that can be applied to each of the phenomena contributes to different layers of analysis when focusing on the decision-making process of migration due to environmental factors. Drawing from the theoretical and methodological frameworks used by scholars, this paper includes an analysis of how they are applied in empirical studies that focus on environmental change and mobility in the Middle East and North Africa (MENA) region.

Findings

Empirical studies in this field for the MENA region are focused on collecting and analyzing data but are not linking it with wider human mobility theoretical and methodological frameworks. The proposal included in this study privileges the use of a qualitative methodology, aimed at obtaining an overview of the individuals’ experience.

Originality/value

This study adds to existing overviews of empirical studies of environmentally induced mobility by analyzing in detail the dimensions used to frame the methodological and theoretical research approaches in the empirical studies used in different disciplines that study the environment and/or human mobility. The studies analyzed focus on the different countries in the MENA region, which has the highest level of forced migratory movements in the world while facing challenges in terms of environmental degradation.

Details

International Journal of Climate Change Strategies and Management, vol. 15 no. 5
Type: Research Article
ISSN: 1756-8692

Keywords

Open Access
Article
Publication date: 11 September 2018

Vivian Bushra Kheir

The purpose of this study is to empirically examine the impact of financial development on poverty reduction in Egypt. The paper also investigates whether financial development…

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Abstract

Purpose

The purpose of this study is to empirically examine the impact of financial development on poverty reduction in Egypt. The paper also investigates whether financial development affects poverty via gross domestic product (GDP) growth.

Design/methodology/approach

This study uses the autoregressive distributed lag approach to estimate two specifications. The first is dependent on poverty by the ratio domestic credit to the private sector (percentage of GDP) and the second is dependent on the poverty by the ratio liquid liabilities to GDP or M3/GDP. The data are annual and cover the period from 1980 to 2015.

Findings

In long run, the study finds that relationship between economic growth and poverty is bidirectional. Financial development and poverty (household final consumption expenditure per capita) are complementary as bidirectional (in Granger sense). In short run, the study finds the bidirectional causality between financial development (real domestic credit to private sector per capita) and poverty reduction.

Practical implications

The findings suggest that governments should remove policies that impede the ability of banks to offer loan products or undermine the commercial incentive structure for banks or borrowers. It is crucial to enhance the role of specialized state-owned banks in financial intermediation.

Social implications

Several attempts have been made to investigate the relationship between financial development and other macroeconomic variables, but few studies have examined the impact of financial development on poverty reduction. Furthermore, the majority of the previous studies are based on Asia and Latin America – affording Egypt very little or no coverage at all.

Details

Review of Economics and Political Science, vol. 3 no. 2
Type: Research Article
ISSN: 2631-3561

Keywords

Open Access
Book part
Publication date: 4 May 2018

Rozanna Dewi, Nasrun Ibrahim, Novi Sylvia, Dahlan Abdullah and Medyan Riza

Purpose – The purpose of this research is to synthesize modified thermoplastic sago starch (TPS) through in-situ mechanism by reacting sago starch with diphenylmethanediisocyanate…

Abstract

Purpose – The purpose of this research is to synthesize modified thermoplastic sago starch (TPS) through in-situ mechanism by reacting sago starch with diphenylmethanediisocyanate (MDI) and castor oil simultaneously, resulting in a more homogenous and finer-sized polyurethane prepolymer (PUP).

Design/Methodology/Approach – The methods used were Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) for thermal characterization and stability of PUP, modified TPS non-extracted and extracted with toluene and water.

Findings – TGA test results presented shows that PUP begins to decompose thermally at a temperature of 300–500 °C. Weight loss occurs rapidly between these temperatures and is completely discharged at a temperature of 500°C, which is called weight loss transition.

Research Limitations/Implications – When extracted with toluene and a water solvent, the melting point and latent heat of fusion slightly decreased; however, it is still higher than the original value of sago. In terms of thermal stability, modified TPS decomposes and loses weight at 150–200 °C in small quantities, continues with weight loss rapidly, and is completely discharged at 500°C. The thermal stability is considered high; thus, modified TPS application can be varied.

Practical Implications – DSC analysis and TGA shows that modified TPS has good thermal characteristics and thermal stability. Modified TPS has a melting point of 104.69°C, and the latent heat of fusion (ΔH) is 234.27 J/g. This value is close to the PUP melting point and latent heat of fusion, which reveals the formation of cross-link between the starch and PUP.

Open Access
Article
Publication date: 25 September 2019

Venkatesh Kodur, Puneet Kumar and Muhammad Masood Rafi

The current fire protection measures in buildings do not account for all contemporary fire hazard issues, which has made fire safety a growing concern. Therefore, this paper aims…

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Abstract

Purpose

The current fire protection measures in buildings do not account for all contemporary fire hazard issues, which has made fire safety a growing concern. Therefore, this paper aims to present a critical review of current fire protection measures and their applicability to address current challenges relating to fire hazards in buildings.

Design/methodology/approach

To overcome fire hazards in buildings, impact of fire hazards is also reviewed to set the context for fire protection measures. Based on the review, an integrated framework for mitigation of fire hazards is proposed. The proposed framework involves enhancement of fire safety in four key areas: fire protection features in buildings, regulation and enforcement, consumer awareness and technology and resources advancement. Detailed strategies on improving fire safety in buildings in these four key areas are presented, and future research and training needs are identified.

Findings

Current fire protection measures lead to an unquantified level of fire safety in buildings, provide minimal strategies to mitigate fire hazard and do not account for contemporary fire hazard issues. Implementing key measures that include reliable fire protection systems, proper regulation and enforcement of building code provisions, enhancement of public awareness and proper use of technology and resources is key to mitigating fire hazard in buildings. Major research and training required to improve fire safety in buildings include developing cost-effective fire suppression systems and rational fire design approaches, characterizing new materials and developing performance-based codes.

Practical implications

The proposed framework encompasses both prevention and management of fire hazard. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified, and detailed strategies are provided to address these limitations using proposed fire safety framework.

Social implications

Fire represents a severe hazard in both developing and developed countries and poses significant threat to life, structure, property and environment. The proposed framework has social implications as it addresses some of the current challenges relating to fire hazard in buildings and will enhance overall fire safety.

Originality/value

The novelty of proposed framework lies in encompassing both prevention and management of fire hazard. This is unlike current fire safety improvement strategies, which focus only on improving fire protection features in buildings (i.e. managing impact of fire hazard) using performance-based codes. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified and detailed strategies are provided to address these limitations using proposed fire safety framework. Special emphasis is given to cost-effectiveness of proposed strategies, and research and training needs for further enhancing building fire safety are identified.

Details

PSU Research Review, vol. 4 no. 1
Type: Research Article
ISSN: 2399-1747

Keywords

Open Access
Article
Publication date: 15 September 2021

Diego Finchelstein, Maria Alejandra Gonzalez-Perez and Erica Helena Salvaj

In this exploratory multiple case study, we aim to compare the internationalization of two state-owned enterprises (SOEs) owned by subnational governments with three owned by…

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Abstract

Purpose

In this exploratory multiple case study, we aim to compare the internationalization of two state-owned enterprises (SOEs) owned by subnational governments with three owned by central governments in Latin America. This study provides a contextualized answer to the question: What are the differences in the internationalization of subnationally owned SOEs compared to central SOEs? This study finds that the speed and diversification of these two types of SOEs’ internationalization differ because they have a different expansion logic. Subnationally owned SOEs have a gradual and diversified expansion following market rules. Central government’s SOEs are specialized and take more drastic steps in their internationalization, which relates to non-market factors.

Design/methodology/approach

This study builds an exploratory qualitative comparative case analysis that uses multiple sources of data and information to develop a comprehensive understanding of SOEs through process tracing.

Findings

The study posits some assumptions that are confirmed in the case analysis. This study finds relevant differences between sub-national (SSOEs) and central authority (CSOEs’) strategies. SSOEs’ fewer resources and needs to increase income push them to follow a gradual market-driven internationalization and to diversify abroad. CSOEs non-gradual growth is justified by non-market factors (i.e. national politics). CSOEs do not diversify abroad due to the broader set of constituencies they have to face.

Research limitations/implications

Given the exploratory comparative case study of this research, the findings are bounded by the particularities of the cases and their region (Latin America). This paper and its findings can be useful for theory building but it does not claim any generalization capacity.

Originality/value

This study adds complexity into the SOEs phenomenon by distinguishing between different types of SOEs. This paper contributes to the study of subnational phenomena and its effect in SOEs’ internationalization process, which is an understudied topic. To the authors’ best knowledge, this is among the first studies that explore subnational SOEs in Latin America.

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