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Article
Publication date: 1 February 2002

J.E. Ruckman, S.G. Hayes and J.H. Cho

Based upon numerous assertions that a garment should be developed to maximise athletes' muscle performance while maintaining freedom of movement, this paper initially discusses…

Abstract

Based upon numerous assertions that a garment should be developed to maximise athletes' muscle performance while maintaining freedom of movement, this paper initially discusses the development of a perfusion suit that utilises a flexible single layer cooling system, with a view to the development of a cooling garment that does not employ a conventional tubing system which can restrict movement. The stages of the development have been described in detail, and an appropriate evaluation completed for both the initially developed perfusion suit and the subsequently developed cooling garment (modified perfusion suit). From results obtained from experiments conducted using the cooling garment, which incorporates super absorbent sodium polyacrylate pads as the cooling component, the following conclusions were drawn. First, anterior thigh temperature was reduced by 4–5°C at the end of the cooling period confirming that the developed cooling garment provides effective cooling. Second, although the difference between the skin temperature of the anterior thigh when cooling is applied to that when cooling is not applied decreased during the exercise period, the difference is still significant confirming that cooling of the anterior thigh by wearing the developed cooling garment persists throughout the duration of exercise.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 1
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 22 February 2013

Caroline J. Smith, Christiano A. Machado‐Moreira, Gijs Plant, Simon Hodder, George Havenith and Nigel A.S. Taylor

The purpose of this paper is to provide footwear designers, manikin builders and thermo‐physiological modellers with sweat distribution information for the human foot.

1013

Abstract

Purpose

The purpose of this paper is to provide footwear designers, manikin builders and thermo‐physiological modellers with sweat distribution information for the human foot.

Design/methodology/approach

Independent research from two laboratories, using different techniques, is brought together to describe sweat production of the foot. In total, 32 individuals were studied. One laboratory used running at two intensities in males and females, and measured sweat with absorbents placed inside the shoe. The other used ventilated sweat capsules on a passive, nude foot, with sweating evaluated during passive heating and incremental exercise to fatigue.

Findings

Results from both laboratories are in agreement. Males secreted more than twice the volume of sweat produced by the females (p<0.01) at the same relative work rate. Both genders demonstrated a non‐uniform sweat distribution, though this was less variable in females. Highest local sweat rates were observed from the medial ankles (p<0.01). The dorsal foot sweated substantially more than the plantar (sole) areas (p<0.01). Sweating on the plantar side of the foot was uniform. Wearing shoes limited the increase in sweat production with increasing load, while the sweat rate of uncovered feet kept increasing with work and thermal load.

Practical implications

The observed variation in sweat rate across the foot shows that footwear design should follow the body mapping principle. Fabrics and materials with different properties can be used to improve comfort if applied to different foot surfaces. The data also demonstrate that foot models, whether physical (manikins) or mathematical, need to incorporate the observed variation across the foot to provide realistic simulation/testing of footwear.

Originality/value

Details

International Journal of Clothing Science and Technology, vol. 25 no. 1
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 December 2001

George Stylios

Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within…

1078

Abstract

Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within the newer research areas under the microscope of the community involved, technical textiles focuses on new, ‘smart’ garments and the initiatives in this field in both the UK and the international community at large. Covers this subject at length.

Details

International Journal of Clothing Science and Technology, vol. 13 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 December 2002

George K. Stylios

Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the…

Abstract

Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the downside part of the industry is garment making which is the least developed side. Posits that the manufacture of clothing needs to become more technologically advanced as does retailing. Closes by emphasising support for the community in all its efforts.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 9 January 2009

Paul W. Partridge and Luiz C. Wrobel

The purpose of this paper is to present an inverse analysis procedure based on a coupled numerical formulation through which the coefficients describing non‐linear thermal…

Abstract

Purpose

The purpose of this paper is to present an inverse analysis procedure based on a coupled numerical formulation through which the coefficients describing non‐linear thermal properties of blood perfusion may be identified.

Design/methodology/approach

The coupled numerical technique involves a combination of the dual reciprocity boundary element method (DRBEM) and a genetic algorithm (GA) for the solution of the Pennes bioheat equation. Both linear and quadratic temperature‐dependent variations are considered for the blood perfusion.

Findings

The proposed DRBEM formulation requires no internal discretisation and, in this case, no internal nodes either, apart from those defining the interface tissue/tumour. It is seen that the skin temperature variation changes as the blood perfusion increases, and in certain cases flat or nearly flat curves are produced. The proposed algorithm has difficulty to identify the perfusion parameters in these cases, although a more advanced genetic algorithm may provide improved results.

Practical implications

The coupled technique allows accurate inverse solutions of the Pennes bioheat equation for quantitative diagnostics on the physiological conditions of biological bodies and for optimisation of hyperthermia for cancer therapy.

Originality/value

The proposed technique can be used to guide hyperthermia cancer treatment, which normally involves heating tissue to 42‐43°C. When heated up to this range of temperatures, the blood flow in normal tissues, e.g. skin and muscle, increases significantly, while blood flow in the tumour zone decreases. Therefore, the consideration of temperature‐dependent blood perfusion in this case is not only essential for the correct modelling of the problem, but also should provide larger skin temperature variations, making the identification problem easier.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 19 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 25 June 2019

Krzysztof Grysa and Artur Maciag

The purpose of this paper is to derive the Trefftz functions (T-functions) for the Pennes’ equation and for the single-phase-lag (SPL) model (hyperbolic equation) with perfusion

Abstract

Purpose

The purpose of this paper is to derive the Trefftz functions (T-functions) for the Pennes’ equation and for the single-phase-lag (SPL) model (hyperbolic equation) with perfusion and then comparing field of temperature in a flat slab made of skin in the case when perfusion is taken into account, with the situation when a Fourier model is considered. When considering the process of heat conduction in the skin, one needs to take into account the average values of its thermal properties. When in biological bodies relaxation time is of the order of 20 s, the thermal wave propagation appears. The initial-boundary problems for Pennes’ model and SPL with perfusion model are considered to investigate the effect of the finite velocity of heat in the skin, perfusion and thickness of the slab on the rate of the thermal wave attenuation. As a reference model, the solution of the classic Fourier heat transfer equation for the considered problems is calculated. A heat flux has direction perpendicular to the surface of skin, considered as a flat slab. Therefore, the equations depend only on time and one spatial variable.

Design/methodology/approach

First of all the T-functions for the Pennes’ equation and for the SPL model with perfusion are derived. Then, an approximate solutions of the problems are expressed in the form of a linear combination of the T-functions. The T-functions satisfy the equation modeling the problem under consideration. Therefore, approximating a solution of a problem with a linear combination of n T-functions one obtains a function that satisfies the equation. The unknown coefficients of the linear combination are obtained as a result of minimization of the functional that describes an inaccuracy of satisfying the initial and boundary conditions in a mean-square sense.

Findings

The sets of T-functions for the Pennes’ equation and for the SPL model with perfusion are derived. An infinite set of these functions is a complete set of functions and stands for a base functions layout for the space of solutions for the equation used to generate them. Then, an approximate solutions of the initial-boundary problem have been found and compared to find out the effect of finite velocity of heat in the skin, perfusion and thickness of the slab on the rate of the thermal wave attenuation.

Research limitations/implications

The methods used in the literature to find an approximate solution of any bioheat transfer problems are more complicated than the one used in the presented paper. However, it should be pointed out that there is some limitation concerning the T-function method, namely, the greater number of T-function is used, the greater condition number becomes. This limitation usually can be overcome using symbolic calculations or conducting calculations with a large number of significant digits.

Originality/value

The T-functions for the Pennes’ equation and for the SPL equation with perfusion have been reported in this paper for the first time. In the literature, the T-functions are known for other linear partial differential equations (e.g. harmonic functions for Laplace equation), but for the first time they have been derived for the two aforementioned equations. The results are discussed with respect to practical applications.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 June 2016

Chupo Ho, Jintu Fan, Edward Newton and Raymond Au

Maintaining air circulation between the wearer and garment layer is crucial for activating heat and moisture transfer from the body. If an air gap is trapped, air circulation may…

Abstract

Purpose

Maintaining air circulation between the wearer and garment layer is crucial for activating heat and moisture transfer from the body. If an air gap is trapped, air circulation may become ineffective and the ventilation of the garment is, thus, hindered. To maintain and extend the air gap, this study aims to propose a design method that involves placing spacer blocks underneath the garment to prevent the fabric from clinging directly to the skin.

Design/methodology/approach

To study the application of this design method, a series of T-shirts were produced and tested using a thermal manikin in standing and walking postures. All the T-shirts were made of fabric ostensibly manufactured to have high air permeability. Porous mesh fabric was used to construct the vented panels on the T-shirts. The test was conducted in a chamber with controlled temperature, relative humidity and wind velocity. Total thermal insulation (Rt) and moisture vapour resistance (Ret) were measured.

Findings

The test results showed that extension of the air gap between wearer and fabric provided higher ventilation to the wearer if the vented panels were also present on the T-shirts. Different placements of the vented panels on the T-shirts also affected the heat and moisture transfer from the thermal manikin.

Research limitations/implications

Due to limited resources, the evaluation of total thermal insulation and moisture vapour resistance was based on the testing result from a thermal manikin instead of any subjective wearer trial.

Practical implications

This research can contribute to the clothing designer who is developing function wear for a better ventilation.

Social implications

This research can contribute to the clothing designer who is developing function wear for a better ventilation.

Originality/value

This study aimed to further develop a new design concept in T-shirt design by improving the construction of the spacer blocks. Fabric with higher air and water vapour permeability was used to determine to what extent this design method is applicable to higher performance on heat and moisture transfer.

Details

Research Journal of Textile and Apparel, vol. 20 no. 2
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 4 September 2017

Chu Po Ho, Jintu Fan, Edward Newton and Raymond Au

In previous studies, enlarging the air gap between fabric and the skin through the placement of spacer blocks has been proven to improve air ventilation, particularly when the…

Abstract

Purpose

In previous studies, enlarging the air gap between fabric and the skin through the placement of spacer blocks has been proven to improve air ventilation, particularly when the pumping effect is activated during movement. These studies evaluated only the total thermal insulation (Rt) and moisture vapour resistance (Ret) by using a fabric thermal manikin. The purpose of this paper is to report the experience, perceived comfort level, and ventilation effect of two designed T-shirts in a wearer trial.

Design/methodology/approach

An athletic T-shirt (Vented Design) was designed by attaching spacer blocks to the underside of the fabric to enlarge the air gap. Eight subjects participated in the wearer trial, which comprised 30 min treadmill running, followed by 10 min of rest. At different points during the 40 min test period, subjects rated their body coolness, skin dryness, and overall comfort of the designed T-shirt. The testing was repeated with participants wearing the same T-shirt but without spacer blocks, which served as a control garment. The mean skin temperature of each subject was also measured to support survey findings.

Findings

The data were evaluated using independent t-tests. The T-shirt with spacer blocks provided higher ventilation than the control T-shirt after 10 min of running. Research limitations – because of limited resources, only eight subjects were recruited to this study. In addition, more T-shirt designs should be tested in the future to elucidate how T-shirt design affects ventilation performance.

Originality/value

This study investigated a T-shirt design wherein the air gap between the skin surface and fabric was increased. The results of the wearer trial showed that this design could be adopted as a design brief for further design development of related clothing. This study has implications for clothing designers developing functional clothing with improved ventilation.

Details

International Journal of Clothing Science and Technology, vol. 29 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 15 March 2013

Claire Greaves, Judy Gilmore, Lizelle Bernhardt and Lisa Ross

The aim of this paper is to explain how University Hospitals of Leicester's Nuclear Medicine service managers needed to reduce waiting times to comply with internal clinical…

1201

Abstract

Purpose

The aim of this paper is to explain how University Hospitals of Leicester's Nuclear Medicine service managers needed to reduce waiting times to comply with internal clinical requirements and with external local primary care trust (PCT) and national Department of Health targets.

Design/methodology/approach

The team undertook a comprehensive service review to identify problem areas and potential improvements, including: process mapping; data gathering (activity and demand, equipment and staff availability/utilisation); external practice reviews, searching evidence bases; and financial implications. This case study describes how an inter‐disciplinary team redesigned the service and used new working methods to reduce waiting times. Their aim was to discuss a service's practical elements and show how innovation leading to sustainable change can be implemented effectively.

Findings

The review highlighted service delivery bottlenecks for myocardial perfusion imaging, which were linked to medical staff shortages, staff use and equipment between hospital sites, and a silo approach to referrals rather than a coordinated organisation‐wide approach.

Practical implications

Introducing enhanced roles allowed nurses, radiographers and technologists to undertake work previously performed by medical staff thus removing a key service bottleneck. Modifications to service delivery and a cultural change in nuclear medicine resulted in a service that was more efficient, flexible and able to cope with increased demand.

Originality/value

These changes meant that minimum waiting‐time targets were achieved, in particular waiting for myocardial perfusion imaging (reduced from 42 weeks in 2005 to two weeks by 2009). Changes allowed service managers to maintain short waiting times in the current, challenging healthcare climate.

Details

International Journal of Health Care Quality Assurance, vol. 26 no. 3
Type: Research Article
ISSN: 0952-6862

Keywords

Article
Publication date: 11 October 2018

Surendra Balaji Devarakonda, Pallavi Bulusu, Marwan Al-rjoub, Amit Bhattacharya and Rupak Kumar Banerjee

The purpose of this study is to evaluate the impact of external head cooling on alleviating the heat stress in the human body by analyzing the temperatures of the core body (Tc)…

Abstract

Purpose

The purpose of this study is to evaluate the impact of external head cooling on alleviating the heat stress in the human body by analyzing the temperatures of the core body (Tc), blood (Tblood) and head (Th) during exercise conditions using 3D whole body model.

Design/methodology/approach

Computational study is conducted to comprehend the influence of external head cooling on Tc, Tblood and Th. The Pennes bioheat and energy balance equations formulated for the whole-body model are solved concurrently to obtain Tc, Tblood and Th for external head cooling values from 33 to 233 W/m2. Increased external head cooling of 404 W/m2 is used to compare the numerical and experimental Th data.

Findings

Significant reductions of 0.21°C and 0.38°C are observed in Th with external head cooling of 233 and 404 W/m2, respectively. However, for external head cooling of 233 W/m2, lesser reductions of 0.03°C and 0.06°C are found in Tc and Tblood, respectively. Computational results for external head cooling of 404 W/m2 show a difference of 15 per cent in Th compared to experimental values from literature.

Originality/value

The development of stress because of heat generated within human body is major concern for athletes exercising at high intensities. This study provides an insight into the effectiveness of external head cooling in regulating the head and body temperatures during exercise conditions.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 10
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of 41