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Article
Publication date: 20 June 2019

Faeze Nejati, Samira Ahmadi and S.A. Edalatpanah

Modern construction methods have been developed with the goal of reducing construction time as much as possible, which results in some situations during construction and within…

Abstract

Purpose

Modern construction methods have been developed with the goal of reducing construction time as much as possible, which results in some situations during construction and within the first few days after it, when concrete is subjected to exceptionally high loads. The precast concrete, which is the concrete in very early ages, may result in severe cracks or damages. In conventional construction projects, sometimes working with concrete, which had not reached its ultimate strength, is an unavoidable matter of fact. This paper aims to discuss these issues.

Design/methodology/approach

Researchers in the field of construction materials have done their best to make some changes in the different parts of the concrete in order to bring about reforms, based on the existing needs, and achieve new quality and primacy from concrete. One kind of concrete, the emergence of which dates back to many years ago, is self-compacting concrete. Thanks to its high efficiency for the parts with complex forms of high-density steel, this kind of concrete suggests new prospects.

Findings

This study aims at evaluating the effect of early loads on the 28-day compressive strength of concretes with zeolite and limestone powder under different curing conditions (wet or dry). In this regard, two self-compacting concrete mix designs with the same ratio of water to cementations materials and 0.4 percent and 10 percent zeolite have been considered; therefore, concrete cube samples with zeolite and limestone powder in different curing conditions at ages of three, one and seven days under preloading with 80–90 percent of compressive strength are damaged, and after curing in different conditions, their 28-day compressive strength is measured. According to the results, the recovery of the 28-day compressive strength of damaged samples, compared to that of intact samples, is possible in all curing conditions. The experiments that have been performed on concrete samples under dry and wet curing conditions show that the full recovery of compressive strength of damaged samples compared to that of intact ones happened only in preloaded samples at the age of one days, and in other ages (three and seven days) the 28-day strength reduction has occurred in damaged samples compared to the that in intact samples. The results of concrete samples with zeolite and without limestone powder at the age of one day indicate the greatest impact on other samples on the 28-day compressive strength of damaged samples compared to that of intact ones, occurring under dry condition.

Originality/value

This research analyzed and studied the influence under wet and dry curing conditions and the presence of limestone powder and zeolite fillers in recovering of the 28-day compressive strength of preloaded concrete samples at early stages (one, three and seven days) after the construction of the concrete.

Details

International Journal of Structural Integrity, vol. 10 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 March 1980

Paul Fieldhouse, SRD BSc(Nut) and AIHE

Two problems for nutrition educators are defining appropriate messages and gaining access to target groups. In addition, communication skills are essential if messages are to be…

Abstract

Two problems for nutrition educators are defining appropriate messages and gaining access to target groups. In addition, communication skills are essential if messages are to be presented in a convincing and persuasive manner. The exercise described by Paul Fieldhouse in this article, is designed to meet these needs by giving students the opportunity to devise suitable nutrition messages and to develop practical communication skills in putting their messages across to lay audiences. Initially, evaluation is restricted to giving as much positive feedback as possible, though later more structured assessment can be introduced. The exercise was successful in establishing links between the Polytechnic department and the local community.

Details

Nutrition & Food Science, vol. 80 no. 3
Type: Research Article
ISSN: 0034-6659

Article
Publication date: 13 August 2018

Hamed Hemmati Pourghashti, Malek Mohammad Ranjbar and Rahmat Madandoust

The purpose of this paper is to conduct a laboratory investigation on measuring the tensile strength of recycled concrete using a double punch test. Furthermore, one of the main…

Abstract

Purpose

The purpose of this paper is to conduct a laboratory investigation on measuring the tensile strength of recycled concrete using a double punch test. Furthermore, one of the main goals of this study is to compare the tensile and compressive strengths of recycled concrete samples.

Design/methodology/approach

Recycled concrete samples were made with variables such as aggregate type (natural stone and aggregate recycled concrete), different water-to-cement ratios and different treatment conditions in the first stage. In the next stage, the double punch test was performed on them, and finally the results obtained from experiments were analyzed and investigated.

Findings

According to the above tests, it was concluded that: first, according to the laboratory results, the strength of concrete containing recycled aggregates becomes closer to the strength of concrete containing natural aggregates whenever the water-to-cement ratio is higher. Second, upon investigating the treatment conditions, it was observed that the treatment had a greater effect on the strength of the recycled concrete. However, this effect was less tangible in tensile strength. Third, upon investigating the results of tensile strength, it can be said that the Barcelona test results were closer to the direct tensile test results compared to the Brazilian test results. This indicates the higher viability of Barcelona’s test results. Fourth, the results obtained from the Barcelona tensile test for recycled concrete were closer to the results of the direct tensile test compared to the concrete containing natural aggregates, which suggests that the Barcelona test is more suitable as a tensile test for recycled concrete. Fifth, the effects of various factors on tensile strength were somewhat less compared to the compressive strength, although very close. Sixth, the relationships provided by the regulation for concrete tensile strength on compressive strength were highly inconsistent with the results obtained from the direct tensile test, for which the consistency was higher for concrete containing natural aggregates compared to recycled concrete. Seventh, the dispersion of results obtained from tensile tests was higher for recycled concrete compared to concrete containing natural aggregates, but lesser of this dispersion was observed in the compressive strength.

Originality/value

According to the laboratory results, the strength of concrete containing recycled aggregates becomes closer to the strength of concrete containing natural aggregates whenever the water-to-cement ratio is higher. Upon investigating the treatment conditions, it was observed that the treatment had a greater effect on the strength of the recycled concrete. However, this effect was less tangible in tensile strength. On the basis on the results of the tensile strength, it can be said that the Barcelona test results were closer to the results of the direct tensile test compared to those of the Brazilian test. This indicates the higher viability of Barcelona’s test results. The results obtained from the Barcelona tensile test for recycled concrete were closer to the results of direct tensile test compared to the concrete containing natural aggregates, which suggests that the Barcelona test is more suitable as a tensile test for recycled concrete. The effects of various factors on tensile strength were somewhat less compared to the compressive strength, although very close. The relationships provided by the regulation for concrete tensile strength on compressive strength were highly inconsistent with the results obtained from the direct tensile test, for which the consistency was higher for concrete containing natural aggregate compared to recycled concrete. The dispersion of results obtained from tensile tests was higher for recycled concrete compared to concrete containing natural aggregate, but lesser of this dispersion was observed in the compressive strength.

Details

International Journal of Structural Integrity, vol. 9 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Abstract

Details

Management Decision, vol. 61 no. 2
Type: Research Article
ISSN: 0025-1747

Article
Publication date: 6 February 2017

Hadi Faghihmaleki, Elmira Khaksar Najafi and Ali Hooshmand Aini

The purpose of this paper is to present a probabilistic assessment and verify the effectiveness of seismic improvement schemes against earthquake, blast and progressive collapse…

Abstract

Purpose

The purpose of this paper is to present a probabilistic assessment and verify the effectiveness of seismic improvement schemes against earthquake, blast and progressive collapse. The probabilistic analysis is performed by taking into account the uncertainties in loading such as planar configuration and amplitude of the blast loading. A standard Monte Carlo (MC) simulation method is employed to generate various concepts of the uncertain parameters within the problem. For a given concept, various local dynamic analyses are performed within a certain range of distance, in order to quantify and locate the damage induced by impact wave on structural elements. In the next step, a limit state analysis is performed in order to investigate whether a progressive collapse mechanism forms under the acting loads or not.

Design/methodology/approach

( | ) and ( | ) are blast fragility and seismic fragility, respectively; ( ) and ( ) are annual occurrence rate of earthquake and blast, respectively. The purpose of the current study is to calculate for the primary structure as well as the retrofitted structure. Annual occurrence rate of earthquake can be calculated by using probability seismic hazard analysis for the site of interest, where the structure is located. In this paper, blast fragility and seismic fragility are defined rather differently; in other words, seismic fragility is defined as the probability of structural collapse given a specified level of seismic intensity whereas blast fragility is defined as the probability of collapse given that a significant blast event takes place. Both blast and earthquake loading conditions involve the activation of energy dissipation mechanism and, as a consequence, both can be resisted employing ductility enhancing techniques, such as column wrapping or jacketing and steel bracing.

Findings

The current paper aims to present a probabilistic assessment of progressive collapse under blast and earthquake loads. Non-dependent and incompatible events are considered to obtain a general rate of collapse. Finally, probabilistic collapse rate was obtained for a moment frame before and after modifying with convergent steel brace (CBF). The purpose of doing so is to investigate whether seismic improvement schemes can reduce collapse risk of different critical events or not.

Originality/value

Objective of the present work is to present a methodology for calculating the annual risk of collapse for a civil structure subjected to both seismic and blast loads, using a bi-hazard approach. Given that a blast event takes place, the probability of progressive collapse is calculated using a MC simulation procedure. The simulation procedure implements an efficient non-linear limit state analysis, formulated and solved as a linear programming problem. The probability of collapse caused by an earthquake event can be calculated by integrating the seismic fragility of the structure and the seismic hazard for the site.

Details

International Journal of Structural Integrity, vol. 8 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 12 April 2022

Ke Zhang, Yujuan Xie, Seyed Ali Noorkhah, Mohsen Imeni and Sapan Kumar Das

In this paper, a combined TODIM-BSC method with the neutrosophical approach for evaluating the performance of a private insurance company has been proposed. In other words, first…

Abstract

Purpose

In this paper, a combined TODIM-BSC method with the neutrosophical approach for evaluating the performance of a private insurance company has been proposed. In other words, first, using the BSC technique, and identify the performance evaluation indicators, then evaluate the performance of the insurance company's agencies and rank them with the TODIM decision-making method.

Design/methodology/approach

The insurance industry has a special prestige and importance in domestic and foreign trade. The evaluation of insurance companies, in addition to informing the stakeholders, increases competition, industry dynamism, sustainable and balanced development of society. The purpose of this paper is to establish a model for evaluating the performance of private insurance companies by adopting multiple-attribute decision-making and Balanced Scorecard (BSC) with single-values neutrosophic numbers (SVNNs) which will be applied by considering a set of indicators and alternatives deliberated with different viewpoints.

Findings

A case study of the private insurance agencies in one of the provinces of Iran based on 26 criteria of agencies is used to confirm the practicality and effectiveness of the proposed model. Finally, there was a discussion about why the results are logical, which shows the strength and robustness of the proposed framework.

Originality/value

To the best of our knowledge, no study has been performed to evaluate the performance of a real-world problem with the integrated TODIM-BSC method in a neutrophilic environment. Therefore, this paper can be effective in bridging the existing research gap and expanding our knowledge of the discussion of evaluating the performance of organizations or companies. Besides, by using these results, the authors can help the planners of these companies as well as similar organizations in attracting satisfaction and retaining target customers.

Open Access
Article
Publication date: 12 September 2019

Geetha Rani Prakasam, Mukesh Mukesh and Gopinathan R.

Enrolling in an academic discipline or selecting the college major choice is a dynamic process. Very few studies examine this aspect in India. This paper makes a humble attempt to…

2962

Abstract

Purpose

Enrolling in an academic discipline or selecting the college major choice is a dynamic process. Very few studies examine this aspect in India. This paper makes a humble attempt to fill this gap using NSSO 71st round data on social consumption on education. The purpose of this paper is to use multinomial regression model to study the different factors that influence course choice in higher education. The different factors (given the availability of information) considered relate to ability, gender, cost of higher education, socio-economic and geographical location. The results indicate that gender polarization is apparent between humanities and engineering. The predicated probabilities bring out the dichotomy between the choice of courses and levels of living expressed through consumption expenditures in terms of professional and non-professional courses. Predicted probabilities of course choices bring in a clear distinction between south and west regions preferring engineering and other professional courses, whereas north, east and NES prefer humanities.

Design/methodology/approach

The present paper follows the same approach as that of Turner and Bowen (1999). The Multinomial regression is specified as P ( M i = j ) = ( exp ( β j × X i ) / j 1 5 exp ( β j × X i ) ) , where P (Mi=j) denotes the probability of choosing outcome j, the particular course/major choice that categorizes different disciplines. This response variable is specified with five categories: such as medicine, engineering, other professional courses, science and humanities. The authors’ primary interest is to determine the factors governing an individual’s decision to choose a particular subject field as compared to humanities. In other words, to make the system identifiable in the MLR, humanities is treated as a reference category. The vector Xi includes the set of explanatory variables and βj refers to the corresponding coefficients for each of the outcome j. From an aggregate perspective, the distribution of course choices is an important input to the skill (technical skills) composition of future workforce. In that sense, except humanities, the rest of the courses are technical-intensive courses; hence, humanities is treated as a reference category.

Findings

The results indicate that gender polarization is apparent between humanities and engineering. The predicated probabilities bring out the dichotomy between the choice of courses and levels of living expressed through consumption expenditures in terms of professional and non-professional courses. Predicted probabilities of course choices bring in a clear distinction between south and west regions preferring engineering and other professional courses, whereas north, east and NES prefer humanities.

Research limitations/implications

Predicted probabilities of course choices bring in a clear distinction between south and west regions preferring engineering and other professional courses, whereas north, east and NES prefer humanities. This course and regional imbalance need to be worked with multi-pronged strategies of providing both access to education and employment opportunities in other states. But the predicted probabilities of medicine and science remain similar across the board. Very few research studies on the determinants of field choice in higher education prevail in India. Research studies on returns to education by field or course choices hardly exist in India. These evidences are particularly important to know which course choices can support student loans, which can be the future area of work.

Practical implications

The research evidence is particularly important to know which course choices can support student loans, which can be the future area of work, as well as how to address the gender bias in the course choices.

Social implications

The paper has social implications in terms of giving insights into the course choices of students. These findings bring in implications for practice in their ability to predict the demand for course choices and their share of demand, not only in the labor market but also across regions. India has 36 states/UTs and each state/UT has a huge population size and large geographical areas. The choice of course has state-specific influence because of nature of state economy, society, culture and inherent education systems. Further, within the states, rural and urban variation has also a serious influence on the choice of courses.

Originality/value

The present study is a value addition on three counts. First, the choice of courses includes the recent trends in the preference over market-oriented/technical courses such as medicine, engineering and other professional courses (chartered accountancy and similar courses, courses from Industrial Training Institute, recognized vocational training institute, etc.). The choice of market-oriented courses has been examined in relation to the choice of conventional subjects. Second, the socio-economic background of students plays a significant role in the choice of courses. Third, the present paper uses the latest data on Social Consumption on Education.

Details

Journal of Asian Business and Economic Studies, vol. 26 no. 2
Type: Research Article
ISSN: 2515-964X

Keywords

Article
Publication date: 10 May 2011

Alison Gillwald and Muriuki Mureithi

The purpose of this paper is to understand the conditions that enabled the end of roaming charges in East Africa in 2006, achieving in weeks what European regulators had struggled

Abstract

Purpose

The purpose of this paper is to understand the conditions that enabled the end of roaming charges in East Africa in 2006, achieving in weeks what European regulators had struggled with for nearly a decade. To do so it aims to explore the factors that drove marginalized operator Zain to seize the competitive advantage created by it having licenses in three adjoining markets.

Design/methodology/approach

The paper draws on the theory of disruptive competition and innovation pioneered by Clayton Christensen to explain the innovative and disruptive nature of the Zain business model. It is drawn on to explain why, despite Zain being unable ultimately to dominate its competitors, it had a sustained disruptive effect on the entire market. This provides a theoretical lens through which to view the empirical evidence acquired through in‐depth interviews and market analysis. This is used to develop a detailed case study on the dropping of roaming charges in East Africa.

Findings

The case study demonstrates the importance of an enabling policy and regulatory environment, which allowed operators to integrate historically separate national networks into cross‐border operations, undermining roaming markets in the region and ending roaming charges in East Africa forever. With the high price of communications in East Africa and the premium charges placed on international mobile roaming, the effect of this move was to compel other regional operators to follow suit, and further, to institute various other pricing strategies in an attempt to retain or recover their dominant positions. As a result, not only did roaming charges disappear across major networks, but the prices of various other mobile services also fell as subscriber numbers soared.

Research limitations/implications

Research in this area is severely constrained by the inability to access pricing, traffic and revenue data from operators that is regarded as competitively sensitive. As a result it is often difficult to assess the immediate gains and losses of competitors and failure to get consistent data over time, the ability to assess lags and long‐term positions. A longer term review of the impact of these developments on pricing and the dynamics of the East African market in future would provide valuable insight into the longer term effects of these developments.

Practical implications

As policy makers and regulators elsewhere in Africa start to emulate European “best practice” regulation, despite the difficulties mature and resourced regulators in the European Union face in instituting legally binding maximum tariffs for roaming, a valuable alternative policy and regulatory strategy exists in the creation of enabling competitive environments in which incentives to reduce to eliminate roaming charge, rather than retain environments in which international call termination on roaming phones can be arbitraged.

Social implications

Even though ultimately Zain was not successful as a disruptive competitor, it forced the dominant operators to reduce their roaming charges that resulted in sustained welfare gains.

Originality/value

This paper provides both novel theoretical insight and empirical evidence to explain the end of roaming charges in East Africa. It nuances perceptions in the popular and technical press that this was purely a market strategy that could be emulated anywhere else. It highlights the necessary enabling policy and regulatory environment that needed to be created and provides empirical evidence of the impact on competition in the market and analyses the outcomes of Zain's short term business strategy, against the longer term disruptive effect on the market.

Details

info, vol. 13 no. 3
Type: Research Article
ISSN: 1463-6697

Keywords

Article
Publication date: 14 May 2018

Ewan Sutherland

This paper aims to examine issues of bribery, cronyism and nepotism in one of the most corrupt countries in Africa.

Abstract

Purpose

This paper aims to examine issues of bribery, cronyism and nepotism in one of the most corrupt countries in Africa.

Design/methodology/approach

This is a single-country case study, drawing on material dating from the mid-1970s, including court cases.

Findings

The corruption is pervasive and systemic, showing severe problems with governance in general, in the sector and against corruption. Nonetheless, two operators, one South African and one Nigerian, have delivered extensive access to mobile networks.

Practical implications

The system of governance requires significant structural reforms, if the burden of corruption is to be reduced.

Originality/value

This paper sheds new and explicit light on the complex history of telecommunications in Nigeria. It adds to the small base of material on corruption in the telecommunications sector. It identifies issues that could usefully be taken up by institutions in Nigeria.

Details

Digital Policy, Regulation and Governance, vol. 20 no. 3
Type: Research Article
ISSN: 2398-5038

Keywords

Article
Publication date: 7 November 2023

Jun Yu, Zhengcong Ma and Lin Zhu

This study aims to investigate the configurational effects of five rules – artificial intelligence (AI)-based hiring decision transparency, consistency, voice, explainability and…

338

Abstract

Purpose

This study aims to investigate the configurational effects of five rules – artificial intelligence (AI)-based hiring decision transparency, consistency, voice, explainability and human involvement – on applicants' procedural justice perception (APJP) and applicants' interactional justice perception (AIJP). In addition, this study examines whether the identified configurations could further enhance applicants' organisational commitment (OC).

Design/methodology/approach

Drawing on the justice model of applicants' reactions, the authors conducted a longitudinal survey of 254 newly recruited employees from 36 Chinese companies that utilise AI in their hiring. The authors employed fuzzy-set qualitative comparative analysis (fsQCA) to determine which configurations could improve APJP and AIJP, and the authors used propensity score matching (PSM) to analyse the effects of these configurations on OC.

Findings

The fsQCA generates three patterns involving five configurations that could improve APJP and AIJP. For pattern 1, when AI-based recruitment with high interpersonal rule (AI human involvement) aims for applicants' justice perception (AJP) through the combination of high informational rule (AI explainability) and high procedural rule (AI voice), there must be high levels of AI consistency and AI voice to complement AI explainability, and only this pattern of configurations can further enhance OC. In pattern 2, for the combination of high informational rule (AI explainability) and low procedural rule (absent AI voice), AI recruitment with high interpersonal rule (AI human involvement) should focus on AI transparency and AI explainability rather than the implementation of AI voice. In pattern 3, a mere combination of procedural rules could sufficiently improve AIJP.

Originality/value

This study, which involved real applicants, is one of the few empirical studies to explore the mechanisms behind the impact of AI hiring decisions on AJP and OC, and the findings may inform researchers and managers on how to best utilise AI to make hiring decisions.

Details

Information Technology & People, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0959-3845

Keywords

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