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1 – 10 of 82Munir Ahmed, Muhammad Shakaib and Mubashir Ali Siddiqui
Combustion of fuel with oxidizer inside a combustion chamber of an internal combustion engine forms inevitable oxides of nitrogen (NOx) due to high temperature at different…
Abstract
Purpose
Combustion of fuel with oxidizer inside a combustion chamber of an internal combustion engine forms inevitable oxides of nitrogen (NOx) due to high temperature at different locations of the combustion chamber. This study aims to quantify NOx formed inside the combustion chamber using two fuels, a conventional diesel (n-heptane) and a biodiesel (methyl oleate).
Design/methodology/approach
This research uses a computational fluid dynamics simulation of chemically reacting fluid flow to quantify and compare oxides of nitrogen (NOx) in a compression ignition (CI) engine. The study expends species transport model of ANSYS FLUENT. The simulation model has provided the temperature profile inside the combustion chamber, which is subsequently used to calculate NOx using the NOx model. The simulation uses a single component hydrocarbon and oxygenated hydrocarbon to represent fuels; for instance, it uses n-heptane (C7H16) for diesel and methyl-oleate (C19H36O2) for biodiesel. A stoichiometric air–fuel mixture is used for both fuels. The simulation runs a single cylinder CI engine of 650 cm3 swept volume with inlet and exhaust valves closed.
Findings
The pattern for variation of velocity, an important flow parameter, which affects combustion and subsequently oxides of nitrogen (NOx) formation at different piston locations, is similar for the two fuels. The variations of in-cylinder temperature and NOx formation with crank angles have similar patterns for the fuels, diesel and biodiesel. However, the numerical values of in-cylinder temperature and mass fraction of NOx are different. The volume averaged static peak temperatures are 1,013 K in case of diesel and 1,121 K in case of biodiesel, while the mass averaged mass fractions of NOx are 15 ppm for diesel and 141 ppm for biodiesel. The temperature rise after combustion is more in case of biodiesel, which augments the oxides of nitrogen formation. A new parameter, relative mass fraction of NOx, yields 28% lower value for biodiesel than for diesel.
Originality/value
This work uses a new concept of simulating simple chemical reacting system model to quantify oxides of NOx using single component fuels. Simplification has captured required fluid flow data to analyse NOx emission from CI engine while reducing computational time and expensive experimental tests.
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Melih Yıldız, Savaş Mutlu, Andras Nagy and Utku Kale
This paper aims to evaluate the hypothetical situation in a resembling airport to Esenboga Airport and analyzes the condition of all ground support equipment (GSE) equipment to be…
Abstract
Purpose
This paper aims to evaluate the hypothetical situation in a resembling airport to Esenboga Airport and analyzes the condition of all ground support equipment (GSE) equipment to be supplied by electricity produced by solar panels mounted on the rooftop of the terminal building. The case is discussed using environmental emissions and economic feasibility. The results of the resembling case can be generalized to all airports for the reduction of emissions caused by ground operations of aviation.
Design/methodology/approach
GSE fleet data which has been prepared by TGS operated in the Esenboğa Airport have been used to calculate emissions, and equivalent electricity consumption. A hypothetical solar panel construction on the rooftop of the terminal building and also the electricity production case was analyzed. Based on the calculations, both fuel and electricity use cases are compared by means of emissions and production costs using real data.
Findings
The electricity production and transmission pose a high value of emissions. Thus, electrification of GSE in the airport need a new approach such as producing the electric energy in the site. This research analyzes the case that the electricity is produced on the rooftop of terminal building and consumed by the GSE fleet. The authors discussed that it is both feasible and possible to electrify all the GSE except a shortage of two cold months with high fuel demand by using electric storage options.
Practical implications
Ground handling is performed by using GSE which is historically powered by diesel and such internal combustion engines which are well known for their high emission rates. As most of the airports reside in populated areas, GSE emissions need to be evaluated for reduction. However the electric energy could be an alternative for GSE emissions reduction
Originality/value
Aviation is a system of many subsystems in which the performance of each unit plays a crucial role in the final success of the system. Concerns on environmental protection make the aviation industry focus on reducing emissions produced during operations. Although aircraft emissions are widely discussed in the literature, ground handling systems which are an integral part of the whole aviation system, also need to be studied regarding the environmental issues. Besides, the European Union has set out targets of reducing emissions at the airports during ground operations to zero. This paper discusses the possibility of the target by comparing various scenarios
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Hamdi Ercan, Cüneyt Öztürk and Mustafa Akın
This paper aims to assess the impact of electrifying the environmental control system (ECS) and ice protection system (IPS), the primary pneumatic system consumers in a…
Abstract
Purpose
This paper aims to assess the impact of electrifying the environmental control system (ECS) and ice protection system (IPS), the primary pneumatic system consumers in a conventional commercial transport aircraft, on aircraft weight, range, and fuel consumption.
Design/methodology/approach
The case study was carried out on Airbus A321-200 aircraft. Design, modelling and analysis processes were carried out on Pacelab SysArc software. Conventional and electrical ECS and IPS architectures were modelled and analysed considering different temperature profiles.
Findings
The simulation results have shown that the aircraft model with ±270 VDC ECS and IPS architecture is lighter, has a more extended range and has less relative fuel consumption. In addition, the simulation results showed that the maximum range and relative fuel economy of all three aircraft models increased slightly as the temperature increased.
Practical implications
Considering the findings in this paper, it is seen that the electrification of the conventional pneumatic system in aircraft has positive contributions in terms of weight, power consumption and fuel consumption.
Social implications
The positive contributions in terms of weight, power consumption and fuel consumption in aircraft will be direct environmental and economic contributions.
Originality/value
Apart from the conventional ECS and IPS of the aircraft, two electrical architectures, 230 VAC and ±270 VDC, were modelled and analysed. To see the effects of the three models created in different temperature profiles, analyses were done for cold day, ISA standard day and hot day temperature profiles.
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Xinyan Bian, Xiaoguang Han, Jiamei Luo, Chengdi Li and Mingxing Hao
The purpose of this study is to prolong the service life of the Al–Si alloy cylinder and achieve the objective of energy saving and emission reduction by the composite treatments.
Abstract
Purpose
The purpose of this study is to prolong the service life of the Al–Si alloy cylinder and achieve the objective of energy saving and emission reduction by the composite treatments.
Design/methodology/approach
Chemical etching + laser texturing + filled MoS2 composite treatment was applied to the friction surface of aluminum–silicon (Al–Si) alloy cylinder. The friction coefficient and wear loss were measured to characterize the tribology property of cylinders.
Findings
The composite-treated Al–Si alloy cylinder had the lowest friction coefficient and weight loss. The friction coefficient and weight loss of the composite treatment were approximately 27.08% and 54.17% lower than those of the untreated sample, respectively. The laser micro-textures control the release of solid lubricant to the interface of friction pairs slowly, which prolongs the service life of cylinders.
Originality/value
The synergistic effect of the chemical etching + laser texturing + filled MoS2 modified the tribology properties of Al–Si alloy cylinder. The chemical etching raised the silicon particles to bear the load, and laser micro-textures control the release of solid lubricant to improve the lubrication property.
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Azadeh Sagheb, Esra’a Alrashydah and Ehsan Vafaeihosseini
With increased populations and movement of people worldwide, traffic emissions will lead to an increase in carbon dioxide emissions, which is one of the greenhouse gases. This…
Abstract
Purpose
With increased populations and movement of people worldwide, traffic emissions will lead to an increase in carbon dioxide emissions, which is one of the greenhouse gases. This will increase outdoor air pollution and other environmental risks that will impact people's health and livelihood, crops, as well as the built environment such as architecture, buildings and other structures. Few studies have been devoted to addressing the effect of air pollution on historic buildings. However, there is no specific study on the impact of traffic-related emissions.
Design/methodology/approach
A thorough analysis has been conducted in selecting eight historic districts (HDs) among all of 31 located within the city of San Antonio. Motor Vehicle Emission Simulator (MOVES) software has been utilized to process the data collected from the average annual daily traffic (AADT) and vehicle operational speeds and evaluate the amounts of emissions for each HD.
Findings
MOVES outcomes showed that HDs are under the threat of deterioration caused by traffic emissions. Therefore, transportation and environmental planners need to implement sustainable solutions to reduce the impact of CO2 emissions on HDs and, ultimately, historic buildings.
Originality/value
This study will help policymakers plan a better course of action for the future conditions associated with the increased traffic volumes. It is also beneficial for the developers, preservationists, architects and all other stakeholders willing to preserve the history of a country.
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Khushdeep Goyal, Davinder Singh, Harvinder Singh and Charanjit Singh
This paper aims to investigate the high temperature corrosion behaviour of ZrO2-reinforced Cr2O3 matrix-based composite coatings on ASTM-SA213-T-22 steel at 900°C in molten salt…
Abstract
Purpose
This paper aims to investigate the high temperature corrosion behaviour of ZrO2-reinforced Cr2O3 matrix-based composite coatings on ASTM-SA213-T-22 steel at 900°C in molten salt environment. The different coatings were deposited by high velocity oxy fuel (HVOF) method.
Design/methodology/approach
Hot corrosion studies were conducted in simulated boiler environment in silicon carbide tube furnace at 900°C for 50 cycles on bare and HVOF-coated boiler steel specimens. Each cycle consisted 50 h of heating in the simulated boiler environment followed by 20 min of cooling in air. The weight change measurements were performed after each cycle to establish the kinetics of corrosion using thermogravimetric technique. X-ray diffraction and scanning electron microscopy techniques were used to analyse the corroded specimens.
Findings
The addition of 20 Wt.% ZrO2 in Cr2O3 helped reduce corrosion rate by 89.25% as compared to that of uncoated specimen. The phase analysis revealed the presence of Cr2O3 and ZrO2 phases in composite coating matrix, which may have prevented the base metal from interacting with the corrosive elements present in the highly aggressive environment and thus had increased the resistance to hot corrosion.
Originality/value
It should be mentioned here that high temperature corrosion behaviour of thermally sprayed ZrO2–Cr2O3 composite coatings has never been studied, and to the best of the authors’ knowledge, it is not available in the literature. Hence, present investigation can provide valuable information for application of ZrO2-reinforced coatings in high temperature fuel combustion environments.
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Ebrahim Merza and Omar Alhussainan
This paper aims to investigate the drivers of foreign direct divestment (FDD), how it relates to foreign direct investment (FDI) flows and stocks and its implications for…
Abstract
Purpose
This paper aims to investigate the drivers of foreign direct divestment (FDD), how it relates to foreign direct investment (FDI) flows and stocks and its implications for developing countries. While divestment occurs for various reasons, it can be explained by reversing the propositions implied by FDI theories.
Design/methodology/approach
The authors combine FDI data and FDI theories to provide theoretical explanations for FDD and what it means for developing countries. FDI stock and flow data are used to derive inferences on trends in FDD and examine the implications of FDI theories on FDD.
Findings
Changes in the modes of global production and the rise of COVID-19 have reinforced the trend of stagnant or diminishing FDI flows observed since the global financial crisis, with implications for FDD. The authors demonstrate how the various FDI theories can be used to explain FDD, except for the currency areas hypothesis. By reviewing the costs and benefits of FDI, it is concluded that shrinking FDI flows and stocks may not be as detrimental for developing economies as it is typically portrayed.
Originality/value
The paper uses two original approaches to measure and explain the motives for FDD. The first is a reassessment of FDI theories in a way that makes them valid theories for FDD. The second original approach is to interpret data on FDI flows and stocks to imply the trends governing FDD, which is useful, as data on foreign divestment are not available on a country or regional basis.
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Longjun Liu, Qing Fan, Ruhong Liu, Guiqing Zhang, Wenhai Wan and Jing Long
This study aims to explore whether digital platform capabilities (integration and reconstruction) affect technological innovation through knowledge bases in the dimensions of…
Abstract
Purpose
This study aims to explore whether digital platform capabilities (integration and reconstruction) affect technological innovation through knowledge bases in the dimensions of breadth and depth and the moderating role of organisational routines updating.
Design/methodology/approach
Hierarchical regression, mediation effect test macro and bootstrap were conducted to empirically analyse two waves of longitudinal survey data from 179 Chinese technology firms.
Findings
Results confirmed that knowledge bases (breadth and depth) mediated the effect of digital platform capabilities (integration and reconstruction) on technological innovation and that updating of organisational routines moderated the relationship between knowledge bases and technological innovation.
Practical implications
These findings offer guidance to firms that aim to achieve technological innovation and advantages, highlighting the importance of digital platform capabilities, knowledge bases and organisational routines updating.
Originality/value
Advancing from existing digital strategies and firm innovation literature, the authors provide a new perspective (knowledge bases) to respond to the information technology (IT) paradox and understand the role of digital platform capabilities in improving technological innovation.
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This paper aims to focus on a medical goods distribution problem and pharmacological waste collection by plug-in hybrid vehicles with some real-world restrictions. In this…
Abstract
Purpose
This paper aims to focus on a medical goods distribution problem and pharmacological waste collection by plug-in hybrid vehicles with some real-world restrictions. In this research, considering alternative energy sources and simultaneous pickup and delivery led to a decrease in greenhouse gas emissions and distribution costs, respectively.
Design/methodology/approach
Here, this problem has been modeled as mixed-integer linear programming with the traveling and energy consumption costs objective function. The GAMS was used for model-solving in small-size instances. Because the problem in this research is an NP-hard problem and solving real-size problems in a reasonable time is impossible, in this study, the artificial bee colony algorithm is used.
Findings
Then, the algorithm results are compared with a simulated annealing algorithm that recently was proposed in the literature. Finally, the results obtained from the exact solution and metaheuristic algorithms are compared, analyzed and reported. The results showed that the artificial bee colony algorithm has a good performance.
Originality/value
In this paper, medical goods distribution with pharmacological waste collection is studied. The paper was focused on plug-in hybrid vehicles with simultaneous pickup and delivery. The problem was modeled with environmental criteria. The traveling and energy consumption costs are considered as an objective function.
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Jerome L. Antonio, Alexander Lennart Schmidt, Dominik K. Kanbach and Natanya Meyer
Entrepreneurial ventures aspiring to disrupt existing market incumbents often use business-model innovation to increase the attractiveness of their offerings. A value proposition…
Abstract
Purpose
Entrepreneurial ventures aspiring to disrupt existing market incumbents often use business-model innovation to increase the attractiveness of their offerings. A value proposition is the central element of a business model, and is critical for this purpose. However, how entrepreneurial ventures modify their value propositions to increase the attractiveness of their comparatively inferior offerings is not well understood. The purpose of this paper is to analyze the value proposition innovation (VPI) of aspiring disruptors.
Design/methodology/approach
The authors used a flexible pattern matching approach to ground the inductive findings in extant theory. The authors conducted 21 semi-structured interviews with managers from startups in the global electric vehicle industry.
Findings
The authors developed a framework, showing two factors, determinants and tactics, that play a key role in VPI connected by a continuous feedback loop. Directed by the determinants of cognitive antecedents, development drivers and realization capabilities, aspiring disruptors determine the scope, focus and priorities of various configuration and support tactics to enable and secure the success of their value proposition.
Originality/value
The authors contribute to theory by showing how cognitive antecedents, development drivers and capabilities determine VPI tactics to disrupt existing market incumbents, furthering the understanding of configuration tactics. The results have important implications for disruptive innovation theory, and entrepreneurship research and practice, as they offer an explanatory framework to analyze strategies of aspiring disruptors who increase the attractiveness of sustainable technologies, thereby accelerating their diffusion.
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