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Article
Publication date: 25 August 2021

Asif Ur Rehman and Vincenzo M. Sglavo

Recent advances in 3D printing construction elements have focused on ordinary Portland cement (OPC) concrete using polymeric binders; herein, this study aims to produce…

Abstract

Purpose

Recent advances in 3D printing construction elements have focused on ordinary Portland cement (OPC) concrete using polymeric binders; herein, this study aims to produce the same using pure water.

Design/methodology/approach

A binder jet printer prototype was used to fabricate specimens that are used to assess geometric and mechanical properties. Two distinct water-based binder formulations, compatible with OPC chemistry and piezoelectric jetting device, were used: pure water and water-polyvinyl alcohol (98:2 w/w) solution.

Findings

This study examines the effect of binder flow rate on dimensional accuracy. Furthermore, the changes in the mechanical properties over time with hydration have been investigated.

Practical implications

Results indicate that the increase in mechanical strength of Portland cement concrete with pure water was consistent; however, it was delayed by the water: PVA (98:2 w/w) solution. Post-curing by water vapor hardened the structure with the removal of layering native to 3DP and decreased infilling porosity by diffusion mechanism.

Originality/value

This paper has used pure water jetting for BJT of Portland cement-containing bodies.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 23 September 2020

Asif Ur Rehman and Vincenzo M. Sglavo

Three-dimensional (3D) printing technology allows geometric complexity and customization with a significant reduction in the structural environmental impact. Nevertheless…

Abstract

Purpose

Three-dimensional (3D) printing technology allows geometric complexity and customization with a significant reduction in the structural environmental impact. Nevertheless, it poses a serious threat to the environment when organic binders are used. Binder jet printing of alkali-activated geopolymer precursor can represent a successful and environmental-friendly alternative.

Design/methodology/approach

The present work reports about the successful 3D printing of metakaolin-based alkali-activated concrete, with dimensional integrity and valuable mechanical behavior.

Findings

The geometric behavior was studied as a function of alkali activator flow rate, and the minimum geometric deviation with complete saturation was recorded at 103 mg/s. The printed specimen is characterized by a modulus of rupture as high as 4.4 MPa at 135 mg/s.

Practical implications

The 3D printed geopolymer-based concrete can be potentially used in a wide range of structural applications from construction to thermal insulation elements.

Originality/value

The analysis of the 3D geopolymer-based concrete printing system and material conducted in this paper is original.

Details

Rapid Prototyping Journal, vol. 26 no. 10
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 12 November 2020

Abid Ullah, HengAn Wu, Asif Ur Rehman, YinBo Zhu, Tingting Liu and Kai Zhang

The purpose of this paper is to eliminate Part defects and enrich additive manufacturing of ceramics. Laser powder bed fusion (L-PBF) experiments were carried to…

Abstract

Purpose

The purpose of this paper is to eliminate Part defects and enrich additive manufacturing of ceramics. Laser powder bed fusion (L-PBF) experiments were carried to investigate the effects of laser parameters and selective oxidation of Titanium (mixed with TiO2) on the microstructure, surface quality and melting state of Titania. The causes of several L-PBF parts defects were thoroughly analyzed.

Design/methodology/approach

Laser power and scanning speed were varied within a specific range (50–125 W and 170–200 mm/s, respectively). Furthermore, varying loads of Ti (1%, 3%, 5% and 15%) were mixed with TiO2, which was selectively oxidized with laser beam in the presence of oxygen environment.

Findings

Part defects such as cracks, pores and uneven grains growth were widely reduced in TiO2 L-PBF specimens. Increasing the laser power and decreasing the scanning speed shown significant improvements in the surface morphology of TiO2 ceramics. The amount of Ti material was fully melted and simultaneously changed into TiO2 by the application of the laser beam. The selective oxidation of Ti material also improved the melting condition, microstructure and surface quality of the specimens.

Originality/value

TiO2 ceramic specimens were produced through L-PBF process. Increasing the laser power and decreasing the scanning speed is an effective way to sufficiently melt the powders and reduce parts defects. Selective oxidation of Ti by a high power laser beam approach was used to improve the manufacturability of TiO2 specimens.

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Article
Publication date: 11 August 2020

Faheem Ur Rehman, Yibing Ding, Abul Ala Noman and Muhammad Asif Khan

Over the past two decades, China’s outward foreign direct investment (OFDI) has risen remarkably. Whether such an increase affects the Chinese export diversification (ED…

Abstract

Purpose

Over the past two decades, China’s outward foreign direct investment (OFDI) has risen remarkably. Whether such an increase affects the Chinese export diversification (ED) is a significant issue that has surprisingly remained unaddressed. This study aims to explain this issue that how OFDI plays a vital role in symmetric and asymmetric effects on its ED.

Design/methodology/approach

The authors introduce a robust nonlinear autoregressive distributed lag (NARDL) model. Ironically, the purpose of this study is to analyze the symmetric and asymmetric effect of OFDI on ED.

Findings

The authors propose that growing OFDI would be more advantageous to China, rather than the policies of contraction. Therefore, the study provides valuable policy insights to consider the long-run asymmetric momentum given to ED by China’s OFDI.

Originality/value

The results of this study may seem to be an important newsletter for further policy discussion on how China can catch up on the benefits of ED through OFDI.

Details

Journal of Chinese Economic and Foreign Trade Studies, vol. 13 no. 2
Type: Research Article
ISSN: 1754-4408

Keywords

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Article
Publication date: 12 January 2021

Faheem Ur Rehman and Abul Ala Noman

China's outward foreign direct investment (OFDI) has risen remarkably over the past two decades. Does such increase affect the sophistication of Chinese exports, is a…

Abstract

Purpose

China's outward foreign direct investment (OFDI) has risen remarkably over the past two decades. Does such increase affect the sophistication of Chinese exports, is a significant issue that has surprisingly remained unaddressed? The purpose of this study is to investigate the impact of Chinese OFDI on bilateral export sophistication of China and its OFDI receiving partner countries during 2003–2017 by applying Poisson pseudo-maximum likelihood approach based on gravity model.

Design/methodology/approach

The analysis has been performed for total sample, region-wise grouped sample (Europe and Central Asia, Middle East and North Africa, Latin America and Caribbean, East Asia and Pacific, South Asia, North America and sub-Saharan Africa) and income-wise grouped sample (high income, upper middle income, lower middle income and lower income group sample).

Findings

The results confirmed the significant and positive effect of Chinese OFDI on bilateral export sophistication in total sample, regions-wise and income groups sample.

Originality/value

The study provides a helpful suggestion regarding policy towards achieving more sophistication in export and thus to achieve comparative advantage in trade.

Details

China Finance Review International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2044-1398

Keywords

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Article
Publication date: 11 November 2020

Faheem Ur Rehman and Abul Ala Noman

Infrastructure deficiency in Southeast Asian countries is ever growing and touched to a level where it harms the local economy as well as the international sector of the…

Abstract

Purpose

Infrastructure deficiency in Southeast Asian countries is ever growing and touched to a level where it harms the local economy as well as the international sector of the country. The gap between demand and supply for infrastructure is constantly on the upswing. The purpose of this study to investigate the effect of infrastructure on exports and foreign direct investment (FDI) inflow in selected Southeast Asian economies.

Design/methodology/approach

This study employs the pooled mean group (PMG) technique to velaborate that how the infrastructure affects export and FDI in the short run and long run during 1990–2018. For cointegration, Pedroni and Kao tests are used. Dynamic ordinary least square (DOLS) and the fully modified least squares (FMOLSs) estimators are employed for robustness check.

Findings

The findings support that aggregate and sub-indices of infrastructure significantly promote the export and FDI inflow in the long run. Also infrastructure, export and FDI inflow are cointegrated in the long run. FMOLS and DOLS found the most robust results.

Originality/value

Infrastructure development in determining trade and FDI has established a significant deal of attention in the modern era where a plethora of research studies encourage the opinion that better infrastructure attracts FDI and enhances export. However, this study uses a global infrastructure index, which comprises the sub-indices like transport, telecommunication, energy and financial sector, which gives us a clear picture regarding how Southeast Asia can catch up FDI and export benefits through infrastructure.

Details

Journal of Economic Studies, vol. 48 no. 7
Type: Research Article
ISSN: 0144-3585

Keywords

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Book part
Publication date: 3 September 2021

Najma Sadiq

The restrictive measures related to the COVID-19 pandemic put a halt to everything across the world. The global crisis hit every sphere of life. The mobility restrictive…

Abstract

The restrictive measures related to the COVID-19 pandemic put a halt to everything across the world. The global crisis hit every sphere of life. The mobility restrictive nature of the pandemic was a major blow to the travel, tourism and hospitality industry. For a country like Pakistan, with an unstable economy and struggling tourism, the pandemic served as ground zero. This chapter critically examines tourism dimensions in Pakistan and how it sustained the impact of various crises. It pays attention to the concepts of vulnerability, social and community resilience, and adaptive capacity to provide a theoretical understanding of the revival of tourism in Pakistan. It also considers the impact of COVID-led measures on the tourism industry and corresponding initiatives of the government. The chapter concludes by arguing that Pakistan should carefully monitor and assess the current debates on tourism policies and practices. The chapter suggests that the national tourism strategy should incorporate a mechanism that can address tourism in crises in addition to addressing the environmental, socio-cultural and economic impact of tourism.

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Article
Publication date: 23 November 2012

Hakeem Ur Rehman, Muhammad Asif, Muhammad Aamir Saeed, Muhammad Asim Akbar and Muhammad Usman Awan

The aim of this case study‐based paper is to study the application of Six Sigma, a breakthrough improvement strategy in the field of cell site construction of a telecom company.

Abstract

Purpose

The aim of this case study‐based paper is to study the application of Six Sigma, a breakthrough improvement strategy in the field of cell site construction of a telecom company.

Design/methodology/approach

This research provides action research of a Six Sigma project using DMAIC methodology carried out in cell site construction function of a telecom company. The research illustrates how the various Six Sigma tools and techniques were applied in a mutually inclusive manner in one project. The infrastructure department of the company had constructed 900 cell sites last year, out of which 150 were not according to standards and were either disapproved by the operations department or underwent maintenance soon after their use. In 2010, the company spent US$ 0.5 million on rework and maintenance at these sites, thus highlighting the urgency of the problem.

Findings

The paper shows how, after the implementation of the Six Sigma project, the company made savings worth US$ 0.45 million.

Originality/value

Six Sigma as a means of waste reduction has gained popularity among researchers and practitioners. The literature on the methodology of Six Sigma and the management approach towards Six Sigma is burgeoning. While various Six Sigma tools and techniques and their application are discussed in literature independent of each other, the need has arisen to observe their systematic application as they apply in a project; every company can use this breakthrough improvement strategy to improve its processes by reducing waste and deriving the financial benefits.

Details

Asian Journal on Quality, vol. 13 no. 3
Type: Research Article
ISSN: 1598-2688

Keywords

Content available
Article
Publication date: 19 September 2017

Wahid Ullah, Takaaki Nihei, Muhammad Nafees, Rahman Zaman and Muhammad Ali

This study aims to investigate risks associated with climate change vulnerability and in response the adaptation methods used by farming communities to reduce its negative…

Abstract

Purpose

This study aims to investigate risks associated with climate change vulnerability and in response the adaptation methods used by farming communities to reduce its negative impacts on agriculture in Pakistan.

Design/methodology/approach

The study used household survey method of data collection in Charsadda district of Khyber Pakhtunkhwa province, involving 116 randomly selected respondents.

Findings

Prevalent crops diseases, water scarcity, soil fertility loss and poor socio-economic conditions were main contributing factors of climate change vulnerability. The results further showed that changing crops type and cultivation pattern, improved seed varieties, planting shaded trees and the provision of excessive fertilizers are the measures adapted to improve agricultural productivity, which may reduce the climate change vulnerability at a household level.

Research limitations/implications

The major limitation of this study was the exclusion of women from the survey due to religious and cultural barriers of in Pashtun society, wherein women and men do not mingle.

Practical implications

Reducing climate change vulnerability and developing more effective adaptation techniques require assistance from the government. This help can be in the form of providing basic resources, such as access to good quality agricultural inputs, access to information and extension services on climate change adaptation and modern technologies. Consultation with other key stakeholder is also required to create awareness and to build the capacity of the locals toward reducing climate change vulnerability and facilitating timely and effective adaptation.

Originality/value

This original research work provides evidence about farm-level vulnerability, adaptation strategies and risk perceptions on dealing with climate-change-induced natural disasters in Pakistan. This paper enriches existing knowledge of climate change vulnerability and adaptation in this resource-limited country so that effective measures can be taken to reduce vulnerability of farming communities, and enhance their adaptive capability.

Details

International Journal of Climate Change Strategies and Management, vol. 10 no. 3
Type: Research Article
ISSN: 1756-8692

Keywords

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Article
Publication date: 25 August 2021

Rizwan Ali, Ramiz Ur Rehman, Madiha Kanwal, Muhammad Akram Naseem and Muhammad Ishfaq Ahmad

This study aims to examine the key determinants of corporate social responsibility (CSR) disclosure of all listed banks that operate their function in an emerging market, Pakistan.

Abstract

Purpose

This study aims to examine the key determinants of corporate social responsibility (CSR) disclosure of all listed banks that operate their function in an emerging market, Pakistan.

Design/methodology/approach

This study applied the principles of systems-oriented theories such as legitimacy, stakeholder and agency theory. The hypothesis is linking the bank’s social disclosure and its determinants are developed. The relevant data was gathered from the bank’s annual reports and Pakistan Stock Exchange from 2008 to 2018. Further, governance attributes and performance measures are used as the predictor variable and the CSR score as the predicted variable. This study applied panel data analysis on the sampled banks to examine the proposed hypothesis for empirical estimation.

Findings

This study’s inclusive results confirm that the hypothesized determinants of board size, foreign directors on board and female directors on board positively impact the CSR disclosure potential. Board size significantly explains the CSR disclosure in all bank samples. The determined performance measures, profitability and liquidity show a significant positive relationship with CSR disclosure except for few exceptions.

Research limitations/implications

This study’s results lack generalizability due to its unique setting; future researchers can extend the research scope in national–international settings and a regional context.

Practical implications

This study enriches the literature on CSR disclosure determinants and is relevant to practice in an emerging context. It can be helpful from a policy perspective; institutions (bodies) that regulate banks should recognize the governance and performance aspects essential to enhancing CSR disclosure and enhancing the bank’s performance hence value.

Originality/value

This research offers empirical evidence that sheds light on the key governance attributes and performance measures that partially affect CSR disclosure and its extent. In doing so, this study’s findings contribute to the literature significantly, along with regulators, shareholders, deposit holders, individual–institutional investors.

Details

Social Responsibility Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1747-1117

Keywords

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