Ahmad Riaz, Chao Zhou, Ruobing Liang and Jili Zhang
This paper aims to present a numerical study on the natural convection, which operates either as an evaporator or condenser unit of the heat pump system to pre-cool and pre-heat…
Abstract
Purpose
This paper aims to present a numerical study on the natural convection, which operates either as an evaporator or condenser unit of the heat pump system to pre-cool and pre-heat the ambient fresh air.
Design/methodology/approach
This study focuses on natural air cooling or heating within the air channel considering the double skin configuration. Particular focus is given to the analysis of airflow and the heat transfer processes in an air channel to cool or heat the ambient fresh air. In this study, the physical model consists of one wall, either heated uniformly or cooled uniformly, whereas the other wall is adiabatic.
Findings
The results show that the variation of both velocity and temperature is observed as the flow transition occurs at the evaporator or condenser wall. In either case, the temperature rises in the range of 6.3–8.4°C with an increase in mass flow rate from 0.07–0.08 kg/s in the photovoltaic thermal condenser part, while in the photovoltaic thermal evaporator part, the change in mass flow rate from 0.048–0.061 kg/s causes a decrease in temperature from 7.1–4.5°C.
Practical implications
The solar-assisted photovoltaic thermal heat pump system, in building façade having an air layer application, is feasible for pre-heating and pre-cooling the ambient fresh air and also reduces the energy needed to treat the fresh air.
Originality/value
The influence of condensing and evaporating temperature under natural convection mode in double skin conformation is considered for pre-heating and pre-cooling of ambient fresh air.
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This study aims to examine the impact of intellectual capital on the underwriting risk of insurance companies in Pakistan.
Abstract
Purpose
This study aims to examine the impact of intellectual capital on the underwriting risk of insurance companies in Pakistan.
Design/methodology/approach
The study used a quantitative research approach and a longitudinal research design, gathering data from 23 insurance companies listed on the Pakistan stock exchange from 2010 to 2022. The value-added intellectual coefficient (VAIC) was used to measure intellectual capital (IC), and unbalanced panel data were analyzed using static and dynamic regression analyses.
Findings
The findings demonstrate a significant association between intellectual capital and underwriting risk in insurance companies in Pakistan. Specific components of intellectual capital, such as human capital efficiency (HCE), structural capital efficiency (SCE) and capital employed efficiency (CEE), have a strong negative impact on underwriting risk. Control variables like return on assets, insurer size and leverage also showed significant relationships with underwriting risk.
Originality/value
This research provides new insights into the theoretical understanding of the insurance industry by establishing a direct link between intellectual capital and underwriting risk in the context of Pakistan. It suggests that by improving aspects of intellectual capital, specifically HCE, SCE and CEE, policymakers and managers can reduce underwriting risk.
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Rehan Zahid, Masjuki Hj. Hassan, Abdullah Alabdulkarem, Mahendra Varman, Md. Abul Kalam, Riaz Ahmad Mufti, Nurin Wahidah Mohd Zulkifli, Mubashir Gulzar, Muhammad Usman Bhutta, Mian Ashfaq Ali, Usman Abdullah and Robiah H. Yunus
There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance…
Abstract
Purpose
There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives.
Design/methodology/approach
In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior.
Findings
In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil.
Originality/value
In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version.
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Waseem Arshad, Muhammad Adnan Hanif, Muhammad Usman Bhutta, Riaz Ahmad Mufti, Samiur Rahman Shah, Muhammad Usman Abdullah and Muhammad Huzaifa Najeeb
This paper aims to present a technique that has been developed to study the wear in the camshaft and tappet. The engine manufacturers use the most suitable materials, lubrication…
Abstract
Purpose
This paper aims to present a technique that has been developed to study the wear in the camshaft and tappet. The engine manufacturers use the most suitable materials, lubrication additives and surface coatings to minimize friction in all the components of the engine. Reduced friction results in less wear of critical engine components. The researchers are constantly trying to find an improved lubrication formula which reduces the wear and friction coefficient at a considerably low price. In this regard, the cam follower interface is of much importance because most of the wear occurs in this interface.
Design/methodology/approach
The tappets and the cam lobes are analyzed to determine wear. A two-dimensional optical surface profilometer is used to measure the tappet wear, and a high-resolution linear variable differential transformer is used for the measurement of cam lobes. Tests are conducted on Mercedes Benz engine OM 646 under constant camshaft speed, constant inlet lubricant temperature and constant lubricant pressure to study the oil rheology on cam tappet wear.
Findings
The results show that the wear occurs on the cam tappet interface, which is almost a linear phenomenon, and it increases with use.
Originality/value
Customized jigs were made to measure wear of camshaft and tappet.
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Ufana Riaz, S.M. Ashraf and Sharif Ahmad
The purpose of this paper is to report a comparative study of conducting polymer (CP) dispersed oil polyurethane coatings derived from a sustainable resource, i.e. polyaniline…
Abstract
Purpose
The purpose of this paper is to report a comparative study of conducting polymer (CP) dispersed oil polyurethane coatings derived from a sustainable resource, i.e. polyaniline (PANI)/coconut oil polyesteramide urethane (CPEAU) and poly(1‐naphthylamine) (PNA)/linseed oil polyurethane (LPUA) coatings.
Design/methodology/approach
The coatings were prepared chemically and were characterized for their physico‐chemical, physico‐mechanical, corrosion protective efficiency, and open circuit potential measurements. The morphological analysis of the corroded carbon steel (CS), coated uncorroded CS, and coated corroded CS specimens, was carried out by SEM analysis.
Findings
The study revealed that the presence of a CP enhanced the corrosion protective efficiency of the sustainable resource‐based organic coatings. The type of CP used also played a major role in defining the corrosion resistance behavior of the coating materials.
Originality/value
The comparative study of anticorrosive properties of CP with oil‐based polyurethane blends has been studied for the first time.
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SYED M. AHMED, RIAZ AHMAD and D. DARSHI DE SARAM
This paper reports a study carried out to compare the attitudes and perceptions of Hong Kong construction contractors and owners on the importance of various construction risks…
Abstract
This paper reports a study carried out to compare the attitudes and perceptions of Hong Kong construction contractors and owners on the importance of various construction risks and also how the risks should be allocated between the parties to the contract. Data were collected by a questionnaire survey on industry professionals representing contractors and owners. Both the owners and the contractors have attached high importance to risk factors such as safety, quality and financial failures. Results also indicate a readiness on the part of the contractors to allocate a greater portion of risks to themselves.
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Riaz Ahmad Mufti, Rehan Zahid, Farrukh Qureshi and Jawad Aslam
The purpose of this paper is to understand the effect of engine operating conditions and lubricant friction modifier on direct acting tappet rotation. In this research work, novel…
Abstract
Purpose
The purpose of this paper is to understand the effect of engine operating conditions and lubricant friction modifier on direct acting tappet rotation. In this research work, novel method of measuring engine tappet rotation speed has been developed. The technique is so novel. It allows the measurement on real production engine with no modification to the engine tappet bore. Also, In this paper, the effect of engine operating conditions and the effectiveness of friction modifier on tappet rotation is reported.
Design/methodology/approach
For the very first time, for the purpose of measuring follower rotation in a real production engine, a 4 × 6 mm2 electronic chip called Gradiometer is mounted outside the tappet housing, allowing the monitoring of tappet rotation speed without the need to machine a hole in the tappet bore. This novel technique is adopted on Mercedes Benz OM464 engine to study the effect of engine conditions and lubricant chemistry on tappet performance.
Findings
The main outcome of this research work is the development of novel method of measuring tappet rotation. Also, during the experiments, it was revealed that although friction modifiers help in reducing friction at the cam/tappet interface, they can also adversely affect the tappet rotation speed.
Originality/value
The novel technique developed in the research work is one of the most cost effective and simple to use. Researches can adopt the technique to study the tribological performance of direct acting tappet on real production engine. Researches acknowledge the effectiveness of friction modifiers in valve train but its effect on rotation which plays a key role in the component durability has not been the focus of most of the researches mainly due to lack of effective techniques.
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Shamraiz Ahmad, Kuan Yew Wong and Srithar Rajoo
The purpose of this paper was to review the indicators for the three aspects (environment, economy and society) of sustainability (the triple-bottom line (TBL) perspective) for…
Abstract
Purpose
The purpose of this paper was to review the indicators for the three aspects (environment, economy and society) of sustainability (the triple-bottom line (TBL) perspective) for manufacturing sectors. In addition, this paper aimed to: document the sustainability indicators for manufacturing sectors; perform an analysis of these indicators to show their evolutional progress and maturity in terms of their consistent, repeated and standardized usage; and highlight the further work needed to make them mature and more standardized.
Design/methodology/approach
The following keywords were used to explore and find the relevant articles: sustainable manufacturing evaluation, sustainability indicators, life cycle assessment, tools for sustainability assessment, and economic and social evaluation in industries. To find articles within this sample, the major focus remained on the terms “indicators,” “metrics,” and “performance measures.” This paper systematically reviewed the studies and analyzed the different sustainability indicators from the TBL viewpoint. Following this, the documented indicators were critically discussed along with their evolutional progress and maturity level.
Findings
The results showed that solid waste was the least used and immature aspect in the environmental category, whereas the more frequently used and developed indicators were related to material used, energy used and air emissions. Economic assessment was most of the time limited to cost-based indicators. From a social viewpoint, most of the reviewed studies were based on workers and local community and society related indicators rather than consumers-based indicators. From a sectoral viewpoint, comparatively, studies for metal manufacturing industries were more focused on all three dimensions of sustainability. On an overall basis, of the 144 discussed indicators, almost 34 percent (49) were used just once. Comparatively, the usage of indicators was more mature in manufacturing activities of developed countries than developing ones. Moreover, the usage of indicators was more common at the product level than at the other levels.
Originality/value
Unlike previous sustainability indicator sets which were generally long lists of proposed indicators rather than applicable and measurable ones, this paper reported the indicator sets based on studies for manufacturing sectors. Moreover, in contrast to previous reviews on indicators which were mostly based on the environmental dimension, this paper included all three dimensions of sustainability in one comprehensive review while focusing on recent studies published from 2007 to 2017. This paper has explored the recent evolutional progress and maturity of sustainability indicators, and provided insights into their development in manufacturing sectors.
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This study will look at the relationship between norms on gender equality on the one hand and the level of gender equality in the political and socioeconomic sphere, the presence…
Abstract
Purpose
This study will look at the relationship between norms on gender equality on the one hand and the level of gender equality in the political and socioeconomic sphere, the presence or absence of armed conflict, and general peacefulness on the other.
Design/methodology/approach
Data on gender equality norms from the World Values Surveys, political and socioeconomic gender equality from the Global Gender Gap Index, armed conflict from the Uppsala Conflict Data Base, and general peacefulness from the Global Peace Index are analyzed in a bivariate correlation.
Findings
The results show a significant association between norms on and attitudes toward gender equality and levels of political and socioeconomic gender equality, absence or presence of armed conflict, and level of general peacefulness.
Research limitations
There is no data base on norms on and attitudes toward the use of violence which is why only levels of violence are included in the study.
Social implications
The study shows that governments, aid agencies, NGOs and others working on conflict prevention and peace building need to focus on improving gender equality in order to achieve a sustainable decrease in conflict levels and an improvement in general levels of peacefulness.
Originality/value
This study is original in that it looks at norms on gender equality on the individual level on the one hand and actual levels of both gender equality and violence in the society, including armed conflict on the other.
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Priyakrushna Mohanty, Sreeraman Nandhi and MB Srinivasan
Purpose: This chapter addresses four primary objectives: evaluating current multinational heritage conservation initiatives, analyzing motivations behind corporate involvement…
Abstract
Purpose: This chapter addresses four primary objectives: evaluating current multinational heritage conservation initiatives, analyzing motivations behind corporate involvement, assessing the challenges, and introducing a Framework for Heritage Conservation as CSR Strategy (FHCCS).
Design/methodology/approach: This research can be categorized as conceptual research. Thematic content analysis has been performed on the data retrieved from 47 papers which were screened and acquired from various academic search engines.
Findings: This chapter revealed that multinational companies engage in heritage conservation initiatives as part of their corporate social responsibility (CSR) strategies, yielding benefits for both heritage sites and surrounding communities. Key motivations include enhancing corporate reputation, stakeholder relations, and long-term sustainability, with the FHCCS offering guidance for policymakers and practitioners.
Research limitations/implications: This chapter aims to provide insights for policymakers, academics, and practitioners, facilitating informed decision-making and enhancing the integration of heritage conservation into CSR strategies on a global scale.
Originality/value: The work tries to fill the research gap in understanding the integration of heritage conservation within CSR frameworks.