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Book part
Publication date: 26 September 2022

James Nolan and James Peoples

The continued rise in e-commerce has contributed to recent growth of the air cargo industry. In addition, international demand for low volume-high value products as well…

Abstract

The continued rise in e-commerce has contributed to recent growth of the air cargo industry. In addition, international demand for low volume-high value products as well as time-sensitive goods continues to enhance demand for air cargo services. This volume consists of 11 chapters exploring whether this transportation sector has positioned itself to successfully take advantage of the economic opportunities associated with changing global demand for goods and demand for timely transportation services. Areas of analysis cover costs and competitiveness, shipper services and air cargo demand, along with international competition and economic development. Employing various empirical techniques and theoretical perspectives, these chapters help the reader to understand the methods by which air cargo companies provide efficient and increasingly affordable services, and also how the use of these services enhances economic growth and development.

Article
Publication date: 17 June 2022

Murat Demir

The purpose of this study is to investigate the effects of air-suction slots geometry on the condensing zone of pneumatic compact spinning.

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Abstract

Purpose

The purpose of this study is to investigate the effects of air-suction slots geometry on the condensing zone of pneumatic compact spinning.

Design/methodology/approach

This paper investigated the condensing zone of pneumatic compact spinning with perforated drum for different structures of air-inlet slot geometry with computational fluid dynamics. For this purpose, three air-suction guides with different air-slots were designed. To create the condensing zone for the numerical simulation, a suction insert and the perforated drum were also designed. Flow velocity components on the X, Y, and Z axes, static pressure distribution and the streamline diagram were used for comparative analysis. Designed air-suction guides were produced with a 3D printer and used for yarn production.

Findings

Numerical simulation results showed that condensing effects were provided for all three types of air-suction guides and approaching air-slots on the suction guides resulted in greater flow components but may cause fluctuations. Experimental results also showed that actual flow velocity components (Z-axis) are effective on hairiness (H) properties of the yarn while assisting flow-velocity components are more effective on the evenness and tenacity properties of the yarn.

Originality/value

This paper presents the numerical flow field simulation of compact spinning for different structures of air-suction guides with detailed measurements. To know the effects of air-suction guides on the condensing zone may be helpful to improve yarn properties. In addition, a 3D printer was used for the production of designed parts.

Details

International Journal of Clothing Science and Technology, vol. 34 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Open Access
Article
Publication date: 1 December 2022

Chaehwan Lim, Gyuseung Kim and Hun-Koo Ha

Since airlines that employ their resources effectively will achieve operating profitability, air route resource allocation is significant for airlines. This study aims to…

Abstract

Purpose

Since airlines that employ their resources effectively will achieve operating profitability, air route resource allocation is significant for airlines. This study aims to investigate an appropriate model to reallocate resources into each air route of an airline company.

Design/methodology/approach

This study proposes a network centralized data envelopment analysis (DEA) models with slack-based measure (SBM). The proposed model not only takes into account the two interconnected stages but also considers the nonradial approach with transfer-in and transfer-out slacks for resource reallocating. Furthermore, the authors modify the objective function to an input-oriented function with SBM, and divide the model into passenger and freight parts, which makes the model more realistic for the characteristic of air routes.

Findings

The empirical analysis using an airline company's internal data provides airline operators with information on how they increase or decrease input resources, which can serve as a practical guideline of resource reallocation. Specifically, the results indicate that the airline company should increase their input resources into long-haul air routes such as KOR-OCN while decreasing their input resources into short-haul air routes such as Korean-Oceania (KOR-OCN), Korean-Chinese (KOR-CHN), Korean-Southeast Asian (KOR-SEA), Korean-Japanese (KOR-JPN).

Originality/value

Although some papers evaluate air route efficiencies based on the DEA approach, a few existing papers have addressed resource allocation for air routes. This paper is the first to study the resource reallocation for air routes based on the DEA approach, contributing to the literature in expanding the scope of research on resource reallocation.

Details

Journal of International Logistics and Trade, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1738-2122

Keywords

Expert briefing
Publication date: 17 November 2022

It did not say how many, but stressed that production was on track despite Western sanctions. Russia's air force has suffered considerable losses of combat aircraft and…

Details

DOI: 10.1108/OXAN-DB274085

ISSN: 2633-304X

Keywords

Geographic
Topical
Article
Publication date: 5 December 2022

Srinivas M.V.V., Mudragada Hari Surya, Devendra Pratap Singh, Pratibha Biswal and Sathi Rajesh Reddy

The purpose of this study is to explore the mist-air film cooling performance on a three-dimensional (3-D) flat plate. In mist-air film cooling technique, a small amount…

Abstract

Purpose

The purpose of this study is to explore the mist-air film cooling performance on a three-dimensional (3-D) flat plate. In mist-air film cooling technique, a small amount of water droplets is injected along with the coolant air. The objective is to study the influence of shape of the coolant hole and operating conditions on the cooling effectiveness.

Design/methodology/approach

In this study, 3-D numerical simulations are performed. To simulate the mist-air film cooling over a flat plate, air is considered as a continuous phase and mist is considered as a discrete phase. Turbulence in the flow is accounted using Reynolds averaged Navier–Stokes equation and is modeled using k–e model with enhanced wall treatment.

Findings

The results of this study show that, for cylindrical coolant hole, coolant with 5% mist concentration is not effective for mainstream temperatures above 600 K, whereas for fan-shaped hole, even 2% mist concentration has shown significant impact on cooling effectiveness for temperatures up to 1,000 K. For given mist-air coolant flow conditions, different trend in effectiveness is observed for cylindrical and fan-shaped coolant hole with respect to main stream temperature.

Research limitations/implications

This study is limited to a flat plate geometry with single coolant hole.

Practical implications

The motivation of this study comes from the requirement of high efficiency cooling techniques for cooling of gas turbine blades. This study aims to study the performance of mist-air film cooling at different geometric and operating conditions.

Originality/value

The originality of this study lies in studying the effect of parameters such as mist concentration, droplet size and blowing ratio on cooling performance, particularly at high mainstream temperatures. In addition, a systematic performance comparison is presented between the cylindrical and fan-shaped cooling hole geometries.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

Keywords

Content available
Article
Publication date: 30 November 2022

Usman Umar Akeel

The purpose of this research is to assess the current level of systems literacy of air force logisticians in Nigeria.

Abstract

Purpose

The purpose of this research is to assess the current level of systems literacy of air force logisticians in Nigeria.

Design/methodology/approach

This research undertook an assessment of the knowledge of air force logistics officers on systems thinking with the aid of a qualitative questionnaire. The questionnaire featured questions on the level of literacy and application of systems thinking by air force logisticians in Nigeria.

Findings

The research finds that the majority of the air force logistics officers have very low levels of knowledge and training in systems thinking.

Originality/value

The research is a unique effort to ascertain the level of systems thinking literacy and training in air force logistics in Nigeria. The study presents a baseline and justification for intervention through an improvement of the logistics curricula used in air force training institutions in Nigeria.

Details

Journal of Defense Analytics and Logistics, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2399-6439

Keywords

Article
Publication date: 30 November 2022

Hamdan Alzahrani, Mohammed Arif, Amit Kant Kaushik, Muhammad Qasim Rana and Hani M. Aburas

A building's Indoor Air Quality (IAQ) has a direct impact on the health and productivity on its occupants. Understanding the effects of IAQ in educational buildings is…

Abstract

Purpose

A building's Indoor Air Quality (IAQ) has a direct impact on the health and productivity on its occupants. Understanding the effects of IAQ in educational buildings is essential in both the design and construction phases for decision-makers. The purpose of this paper is to outline the impact air quality has on occupants' performance, especially teachers and students in educational settings.

Design/methodology/approach

This study aims to evaluate the effects of IAQ on teachers' performances and to deliver air quality requirements to building information modelling-led school projects. The methodology of the research approach used a quasi-experiment through questionnaire surveys and physical measurements of indoor air parameters to associate correlation and deduction. A technical college building in Saudi Arabia was used for the case study. The study developed an artificial neural network (ANN) model to define and predict relationships between teachers' performance and IAQ.

Findings

This paper contains a detailed investigation into the impact of IAQ via direct parameters (relative humidity, ventilation rates and carbon dioxide) on teacher performance. Research findings indicated an optimal relative humidity with 65%, ranging between 650 to 750 ppm of CO2, and 0.4 m/s ventilation rate. This ratio is considered optimum for both comfort and performance

Originality/value

This paper focuses on teacher performance in Saudi Arabia and used ANN to define and predict the relationship between performance and IAQ. There are few studies that focus on teacher performance in Saudi Arabia and very few that use ANN in data analysis.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 22 November 2022

Cleopatra Oluseye Ibukun and Wuraola Mahrufat Omisore

This paper examines the long-run and dynamic causal relationship among air pollution, health expenditure and economic growth in Mexico, Indonesia, Nigeria and Turkey (MINT…

Abstract

Purpose

This paper examines the long-run and dynamic causal relationship among air pollution, health expenditure and economic growth in Mexico, Indonesia, Nigeria and Turkey (MINT countries).

Design/methodology/approach

The bounds test approach to cointegration and causality test was employed on data covering 1995–2018.

Findings

The study shows evidence of a long-run relationship among the variables in MINT countries and the causality test confirms the existence of a bidirectional causal nexus between health expenditure and economic growth in the four countries. It also confirms that there is a bidirectional causal relationship between carbon dioxide (CO2) emission and economic growth, except in Nigeria where a unidirectional causal relationship was found running from CO2 emissions to economic growth. In addition, a bidirectional causal relationship was found between air pollution and health expenditure in Turkey, while no causal relationship was found among these variables in Nigeria.

Research limitations/implications

This study is limited by available data and it only focuses on four emerging economies. To address this, future studies can expand this scope to more emerging economies with severe air pollution and also extend the scope when more recent data becomes available.

Practical implications

This study suggests that pollution standards in MINT countries should be monitored and enforced with transparency so as to mitigate its health implications and ensure the sustainability of economic growth.

Social implications

The study confirms the importance of keeping air pollution as low as possible because of its negative effect on health and economic output.

Originality/value

The study accounts for the complexity of each MINT country instead of providing a general discussion on the relationship between air pollution, health expenditure and economic growth in MINT countries.

Details

Journal of Economic and Administrative Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1026-4116

Keywords

Article
Publication date: 21 September 2022

Wenliang Zhang, Heng Huang, Guogang Gao and Xiaopeng Xie

The purpose of this paper is to design the novel oil–air distributor (N-OAD). Its structure design, oil feeding reliability, service life and viscosity properties of air

Abstract

Purpose

The purpose of this paper is to design the novel oil–air distributor (N-OAD). Its structure design, oil feeding reliability, service life and viscosity properties of air bubble (AB) oil were analyzed. Meanwhile, the formation mechanism of AB oil was established based on Kelvin–Helmholtz instability.

Design/methodology/approach

First, oil–air distributor (OAD) and N-OAD were randomly selected for testing when the air pressure was 0.25 MPa and oil feeding was 100 times per hour. Then, the bubbles were found in the lubricant during the experiment, and the void fraction and viscosity properties of AB oil were tested by image processing method and the MARS 40 rheometer, respectively.

Findings

N-OAD has longer service life and higher working reliability than OAD. The key factors of AB oil formation were air pressure and oil feeding. And the void fraction of AB oil has different results on the viscosity at high and low shear rates.

Originality/value

The outcome of this research paper gives an insight to improve the reliability of oil–air lubrication systems and the safety factor of machine tool spindle operation.

Details

Industrial Lubrication and Tribology, vol. 74 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 12 October 2022

Fateme Sayanjali, Nazanin Ezazshahabi and Fatemeh Mousazadegan

The aim of the present study is to investigate the effect of fabric weave structure on air permeability and its relation with the garment ventilation.

Abstract

Purpose

The aim of the present study is to investigate the effect of fabric weave structure on air permeability and its relation with the garment ventilation.

Design/methodology/approach

For this purpose, five groups of cotton/polyester shirting fabrics with plain, T2/1, T2/2, T3/1 and T3/3 weave structures were studied. In order to evaluate ventilation, the garment samples were prepared in different sizes, so that the thickness of the air gap formed between the garment and the body simulator varies by zero, 1.5, 1.2 and 2.9 cm. The effect of wind and its speed (1, 2 and 3 m/s) on clothing ventilation has also been evaluated.

Findings

The results indicated that the rise of wind speed and air gap thickness, due to the increased convective heat transfer, would diminish the air gap temperature of clothing and improves its ventilation. In addition, the fabric weave pattern influences the air ability to pass through the fabric, thus affecting the ventilation capability of the garment.

Originality/value

Garments made of fabrics with higher structural firmness, such as the plain, not only have lower air permeability, but also has weaker ventilation capability.

Details

International Journal of Clothing Science and Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0955-6222

Keywords

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