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1 – 10 of over 5000Sofien Benltoufa, Hind Algamdy, Adel Ghith, Faten Fayala and Lubos Hes
The paper aims to investigate the dynamic measurement of the water vapour resistance. The water vapour diffusion kinetics depends on the fibre’s material. So, water vapour…
Abstract
Purpose
The paper aims to investigate the dynamic measurement of the water vapour resistance. The water vapour diffusion kinetics depends on the fibre’s material. So, water vapour resistance measurement times till the equilibrium steady state can vary in the case of natural fibres compared to synthetic fibres. Devices for determining water vapour resistance according to the ISO 11092 standard allow static values to be measured.
Design/methodology/approach
In this study to investigate the dynamic of the water vapour resistance, a new parameter named “holding period” was introduced and defined as the time from sample placement on the measuring head until the measuring process begins. The holding period was varied as 0, 30, 60, 90, 120, 180, 240 and 300 s. Wool and cotton knitted fabrics were tested as natural fibres and compared to 100% polyester and 90% polyester/10% elastane as synthetic fibres. Measurements were conducted under both air velocities of 1 and 2 m/s. The experimental test data were statistically analysed based on ANOVA and four-in-one residual plots.
Findings
Statistical analysis of experimental tests shows that the holding period affects water vapour resistance in both air velocities of 1 and 2 m/s and on the measured values in the case of hydrophilic fibres.
Research limitations/implications
The study of the dynamic relative water vapour permeability of natural and synthetic is an important area of interest for future research.
Practical implications
It is recommended to hold the samples on the top of the head measurement before starting the test.
Originality/value
Following the ISO 11092 standard, the static values of the water vapour resistance were measured without considering the dynamic behaviour of the water vapour diffusion through the textile fabrics. This paper fulfils an experimental dynamic measurement of the water vapour resistance.
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Usama Afzal, Kanza Maryam, Fatima Afzal and Muhammad Aslam
The purpose of this study is to fabricate a highly sensitive humidity sensor for observing the humidity effect on a robot’s body as an application of the Internet of Things. The…
Abstract
Purpose
The purpose of this study is to fabricate a highly sensitive humidity sensor for observing the humidity effect on a robot’s body as an application of the Internet of Things. The sensor has been fabricated by depositing a thin sensing layer of nickel phthalocyanine (NiPc) between two silver electrodes.
Design/methodology/approach
The structure of the thin film was observed by X-ray diffraction, optical properties by UV Vis and surface morphology by scanning electron microscope. The capacitance and the resistance with respect to change in relative humidity from 0 to 100%RH have been measured by LCR meter at 1 kHz.
Findings
The sensor’s response time is 7.5 s and its recovery time is 3.7 s, with high sensitivity of 127,259 pF/%RH and 332.287 MΩ/%RH. The authors have also used a proposed sensor on a steel body and observed humidity values. The analysis of all measured values was performed through the classical and neutrosophic approaches. By comparing, the authors have observed that the neutrosophic approach is more efficient in analyzing the sensor data.
Originality/value
In this work, the authors will fabricate a capacitive and resistive-type humidity sensor using the thin film of NiPc. The structural, optical and morphological properties of NiPc thin film will be investigated with different characterization techniques. The electric properties, i.e. capacitance and resistance, will be measured at intervals with an LCR meter by changing relative humidity (%RH). Moreover, the measured data will be analyzed through different statistical approaches, as already used in [12].
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Shanmugan Subramani and Mutharasu Devarajan
Polymer-based thermal interface materials (TIMs) are having pump out problem and could be resolved for reliable application. Solid-based interface materials have been suggested…
Abstract
Purpose
Polymer-based thermal interface materials (TIMs) are having pump out problem and could be resolved for reliable application. Solid-based interface materials have been suggested and reported. The purpose of this paper is suggesting thin film-based TIM to sustain the light-emiting diode (LED) performance and electronic device miniaturization.
Design/methodology/approach
Consequently, ZnO thin film at various thicknesses was prepared by chemical vapour deposition (CVD) method and tested their thermal behaviour using thermal transient analysis as solid TIM for high-power LED.
Findings
Low value in total thermal resistance (Rth-tot) was observed for ZnO thin film boundary condition than bare Al boundary condition. The measured interface (ZnO thin film) resistance {(Rth-bhs) thermal resistance of the interface layer (thin film) placed between metal core printed circuit board (MCPCB) board and Al substrates} was nearly equal to Ag paste boundary condition and showed low values for ZnO film prepared at 30 min process time measured at 700 mA. The TJ value of LED mounted on ZnO thin film (prepared at 30 min.) coated Al substrates was measured to be 74.8°C. High value in junction temperature difference (ΔTJ) of about 4.7°C was noticed with 30 min processed ZnO thin film when compared with Al boundary condition. Low correlated colour temperature and high luminous flux values of tested LED were also observed with ZnO thin film boundary condition (processed at 30 min) compared with both Al substrate and Ag paste boundary condition.
Originality/value
Overall, 30 min CVD processed ZnO thin film would be an alternative for commercial TIM to achieve efficient thermal management. This will increase the life span of the LED as the proposed material decreases the TJ values.
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Niranjan Chikkanna, Shankar Krishnapillai and Velmurugan Ramachandran
Auxetics are the class of cellular materials with a negative Poisson’s ratio. This paper aims to study the low-cost 3D printing capabilities and printing variations and improve…
Abstract
Purpose
Auxetics are the class of cellular materials with a negative Poisson’s ratio. This paper aims to study the low-cost 3D printing capabilities and printing variations and improve the indentation performance of the re-entrant diamond auxetic metamaterial by tuning the structural parameters that have not been reported.
Design/methodology/approach
The design of experiment strategy was adopted to study the influence of re-entrant angle, diamond angle and thickness-to-length ratio on relative density, load, stiffness and specific energy absorption (SEA) during indentation experimentally. Grey relational analysis was chosen as a multi-objective optimisation technique to optimise structural performance. Surrogate models were proposed to uphold the metamaterial’s tailorability for desired application needs. The fit and efficacy of the proposed models were tested using specific statistical techniques. The predominant deformation mechanisms observed with the alteration in structural parameters were discussed.
Findings
The improvements noticed are 48 times hike in load, 112 times improvement in stiffness and 10 times increase in SEA for optimised structures. The surrogate models are proven to predict the outputs accurately for new input parameters. In-situ displacement fields are visualised with an image processing technique.
Originality/value
To the best of the authors’ knowledge, the indentation performance of the re-entrant diamond auxetic metamaterials has not been reported and reported for the first time. The influence of geometrical parameters on the newly developed structure under concentrated loading was evaluated. The geometry-dependent printing variations associated with 3D printing have been discussed to help the user to fabricate re-entrant diamond auxetic metamaterial.
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Michele Costa and Flavio Delbono
This paper aims to investigate the impact of cooperative firms on the patterns of regional economic resilience in Italy from 2008 to 2019.
Abstract
Purpose
This paper aims to investigate the impact of cooperative firms on the patterns of regional economic resilience in Italy from 2008 to 2019.
Design/methodology/approach
This study uses regional statistics to compute indices of resilience for both real GDP per capita and employment during both recovery and resistance periods. By means of a linear model, the authors investigate the relationships between indices of resilience and the cooperative presence, while controlling for a set of demographic, social and economic variables.
Findings
This study shows that during (and after) recessions such regional indices exhibit very different patterns, with notably poorer performance observed in Southern regions compared to the rest of the country. Furthermore, this study illustrates that the size of the cooperative employment improves the overall resilience of regional employment, especially during recovery periods.
Social implications
The findings hint at policies enhancing the strength and scope of the cooperative movement as a driver of territorial resilience.
Originality/value
To the best of the authors’ knowledge, this is the first study in relating territorial resilience and the presence of a type of companies. This study performs the analysis at the regional level regarding cooperative enterprises. The new findings hint at some policies enhancing the strength and scope of the cooperative movement.
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Reannan Boisvert, Meredith McQuerry and Sheryl Schofield
Clothing fit, including garment ease and drape, impacts the volume of air between clothing layers and the body, directly affecting the amount of heat that can be transferred…
Abstract
Purpose
Clothing fit, including garment ease and drape, impacts the volume of air between clothing layers and the body, directly affecting the amount of heat that can be transferred through a multi-layer clothing system. As most acute firefighting fatalities are caused by overexertion and heat strain, the purpose of this research was to determine the impact of ease allowances on air gaps in structural firefighting turnout suits and their subsequent effect on total heat loss (THL) when worn on a three-dimensional form.
Design/methodology/approach
Four turnout suits with chest ease allowances of 6″, 8″, 10″ and 12″ were evaluated using an ANDI dynamic sweating thermal manikin. The average predicted manikin THL of each ensemble was calculated from the thermal and evaporative resistance measurements. A three-dimensional (3D) body scanner was utilized to calculate the distance and volume of clothing air gaps between the base layer and each turnout suit.
Findings
Results demonstrate that reductions in upper body ease measurements trend towards statistically significant increases in THL, to a point, with fit limitations being reached before benefits can be significantly realized. An increase in standard chest ease measurements significantly decreased heat loss, even when forced convection from movement was considered.
Originality/value
This is the first article of its kind to explore the relationship between garment ease and predicted manikin THL, especially for fire service protective clothing. Findings indicate a valid recommendation for turnout gear designers and manufacturers to optimize clothing fit to improve breathability and potentially reduce incidents of heat strain in the fire service.
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Burak Sari, Memik Bunyamin Uzumcu and Kubra Ozsahin
The study aimed to investigate the impact of mechanically recycled cotton fibres from pre-consumer waste, blended with virgin cotton at varying ratios, on the mechanical and…
Abstract
Purpose
The study aimed to investigate the impact of mechanically recycled cotton fibres from pre-consumer waste, blended with virgin cotton at varying ratios, on the mechanical and fastness properties of knitted fabrics.
Design/methodology/approach
Single jersey fabrics were produced using open-end rotor yarns with two different yarn counts, which were made from cotton blends obtained at three different mechanical recycled cotton blend ratios. The fabrics were then comparatively analysed for pilling resistance, bursting strength, dimensional stability, and fastness to perspiration, water, and rubbing. The investigations included fabrics made from 100% virgin cotton to determine the impact of mechanically recycled cotton fibres on the final fabric properties.
Findings
It was observed that using MR-CO at different ratios generally produced results similar to the usage properties obtained when using virgin cotton.
Originality/value
The study looked in detail at the effect of using mechanically recycled cotton (MR-CO) on the yarn properties and the mechanical and colour fastness properties of the fabrics produced using them. It was found that MR-CO has the potential to be an alternative fibre source to virgin cotton, not only mechanically but also in terms of colour fastness. Previous studies have commonly used MR-CO in fixed ratios or by incorporating various fibres into the blend. However, in this study, we determined the suitability of fabrics for their intended use by gradually increasing the MR-CO blend ratios and more clearly assessing the impact of MR-CO on fabric properties.
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Yanghao Zhu, Lirong Long, Wenxing Liu, Peipei Shu and Siyuan Chen
In the period of organizational change and transformation, the attitude of employees towards change has become a key factor in the success of organizational change. Based on the…
Abstract
Purpose
In the period of organizational change and transformation, the attitude of employees towards change has become a key factor in the success of organizational change. Based on the uncertainty management theory (UMT), the paper considers authentic leadership as an important antecedent of employee resistance to change and explores the mediating role of perceived uncertainty and the moderating role of uncertainty avoidance between authentic leadership and employee resistance to change.
Design/methodology/approach
The paper conducted a questionnaire survey study and a scenario experimental study. In study 1, the authors collected two stages of data from 256 employees in Central China, one month apart. In study 2, the authors designed a scenario experiment and invited 130 Chinese adults to participate.
Findings
The authors find that authentic leadership can effectively reduce employee resistance to change by reducing employee perceived uncertainty. In addition, for individuals with a higher (vs lower) degree of uncertainty avoidance, the direct impact of authentic leadership on perceived uncertainty and the indirect impact of authentic leadership on resistance to change through perceived uncertainty are both stronger (vs lower).
Originality/value
The presented results reveal the mechanism between authentic leadership and employee resistance to change from cognitive perspective and depict an important step toward understanding how authentic leadership and employee uncertainty avoidance interact and how they interact with employee resistance to change.
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With the upgrade of natural language interaction technology, the simulation extension of intelligent voice assistants (IVAs) and the uncertainty of products and services have…
Abstract
Purpose
With the upgrade of natural language interaction technology, the simulation extension of intelligent voice assistants (IVAs) and the uncertainty of products and services have received more and more attention. However, most of the existing research focuses on investigating the application of theories to explain consumer behavior related to intention to use and adopt IVAs, while ignoring the impact of its privacy issues on consumer resistance. This article especially examines the negative impact of artificial intelligence-based IVAs’ privacy concerns on consumer resistance, and studies the mediating effect of perceived creepiness in the context of privacy cynicism and privacy paradox and the moderating effect of anthropomorphized roles of IVAs and perceived corporate social responsibility (CSR) of IVAs’ companies. The demographic variables are also included.
Design/methodology/approach
Based on the theory of human–computer interaction (HCI), this study addresses the consumer privacy concerns of IVAs, builds a model of the influence mechanism on consumer resistance, and then verifies the mediating effect of perceived creepiness and the moderating effect of anthropomorphized roles of IVAs and perceived CSR of IVAs companies. This research explores underlying mechanism with three experiments.
Findings
It turns out that consumers’ privacy concerns are related to their resistance to IVAs through perceived creepiness. The servant (vs. partner) anthropomorphized role of IVAs is likely to induce more privacy concerns and in turn higher resistance. At the same time, when the company’s CSR is perceived high, the impact of the concerns of IVAs’ privacy issues on consumer resistance will be weakened, and the intermediary mechanism of perceiving creepiness in HCI and anthropomorphism of new technology are further explained and verified. The differences between different age and gender are also revealed in the study.
Originality/value
The research conclusions have strategic reference significance for enterprises to build the design framework of IVAs and formulate the response strategy of IVAs’ privacy concerns. And it offers implications for researchers and closes the research gap of IVAs from the perspective of innovation resistance.
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Fatih Celebioglu and Thomas Brenner
The purpose of this paper is to explain the effects of innovation, specialisation, qualifications and sectoral structure on the resilience of German regions (municipal level…
Abstract
Purpose
The purpose of this paper is to explain the effects of innovation, specialisation, qualifications and sectoral structure on the resilience of German regions (municipal level) facing the Great Recession in 2008/2009.
Design/methodology/approach
To calculate the effects of various variables on the resilience of German regions against the Great Recession, the authors use quantile regressions. To measure resilience, the authors create a number of indexes representing different parts of the economy: resistance performance index, recovery performance index, shift-share resistance index, shift-share recovery index, manufacturing resistance index, manufacturing recovery index, service resistance index and service recovery index.
Findings
The results of this study confirm that locations with employment growth before the crisis and with a good industry structure show better employment dynamics during and after the crisis. The authors find evidence for positive relationship between innovativeness, qualification, the share of the service sector, specialisation and resistance. The authors obtain positive results for related variety and both resistance and recovery. The share of the manufacturing sector only shows a positive relationship with recovery.
Originality/value
The authors expand the existing literature in three aspects: First, instead of using regions as observation units, the authors conduct the analyses on the basis of municipalities and their surroundings. By doing so, the authors reduce the modifiable area unit problem because the authors do not rely on regions defined for administrative reasons. Second, the authors apply quantile regressions to detect nonlinear effects. Third, in addition to the resilience of the whole economy, the authors also study the resilience of the manufacturing and service sectors separately and examine the resilience of the local shift effect.
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