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11 – 20 of 140Antonin Havelka, Viera Glombikova, Zdenek Kus and Michal Chotebor
The purpose of this paper is to deal with performance verification of thermal insulation fillings that are used for outer clothes into cold environments. Thermal properties of…
Abstract
Purpose
The purpose of this paper is to deal with performance verification of thermal insulation fillings that are used for outer clothes into cold environments. Thermal properties of filling materials (down and three sophisticated fillings) were tested under condition approaching real weather conditions in Middle Europe.
Design/methodology/approach
In the paper, modern method of thermal resistance Rct measurement, by Sweating Guarded-Hotplate system, was compared with method of Technical University of Liberec (TUL method). The TUL method shows good results and it is applicable even at ambient temperatures below zero, which fully corresponds to real application of the insulation filling.
Findings
Evaluation of fibre battings were carried out even at temperatures below the freezing point, which is important for simulation of actual application of these filling structures. The highest thermal resistance of goose down confirm that natural materials have their irreplaceable position, especially in application into clothes for extreme conditions.
Research limitations/implications
There does not include effect of the humidity change on thermal insulation properties. It will be subject of further research of authors.
Originality/value
The investigation of thermal insulation properties were carried out under conditions approaching real application of tested materials, namely, at low ambient temperature.
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Milena Kiliszkiewicz, Dariusz Przybylski, Jan Felba and Ryszard Korbutowicz
The purpose of this paper is to analyze the individual steps during the printing of capacitor structures. The method of substrate preparation, the obtained roughness of conductive…
Abstract
Purpose
The purpose of this paper is to analyze the individual steps during the printing of capacitor structures. The method of substrate preparation, the obtained roughness of conductive and dielectric layers are examined. Moreover, the capacitances of the obtained capacitors were examined.
Design/methodology/approach
Surface roughness and microscopic analysis were used to assess the quality of printed conductive structures. Two criteria were used to assess the quality of printed dielectric structures: the necessary lack of discontinuity of layers and minimal roughness. To determine the importance of printing parameters, a draft experimental method was proposed.
Findings
The optimal way to clean the substrate has been determined. The most important parameters for the dielectric layer (i.e. drop-space, table temperature, curing time and temperature) were found.
Research limitations/implications
If dielectric layers are printed correctly, most problems with printing complex electronic structures (transistors, capacitors) will be eliminated.
Practical implications
The tests performed identified the most important factors for dielectric layers. Using them, capacitors of repeatable capacity were printed.
Originality/value
In the literature on this subject, no factors were found which were responsible for obtaining homogeneous dielectric layers.
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Wiah Wardiningsih and Olga Troynikov
This study aimed to evaluate the performance attributes relevant to thermal wear comfort of the commercially available hip protective pads and materials intended for impact…
Abstract
Purpose
This study aimed to evaluate the performance attributes relevant to thermal wear comfort of the commercially available hip protective pads and materials intended for impact protection that can be used for the hip protective pad.
Design/methodology/approach
The performance attributes relevant to thermal wear comfort (i.e. dry thermal resistance and evaporative resistance) of the pads were tested using MTNW Integrated Sweating Guarded Hotplate (iSGHP).
Findings
It was found that: the pad with more porous structure has more advantages in terms of evaporative resistance; the permeability index will be higher on the pad with an opening such as a segmented pad; the permeability index will be lower on the thicker and larger pad. The pocket fabric with open structure will have lower dry thermal resistance and evaporative resistance.
Originality/value
The study results showed that the properties of the utilised materials influenced thermal comfort performance. These results could be useful for designing and engineering hip protective garments.
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Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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C.A. Wilson, B.E. Niven and R.M. Laing
The purposes of this work were to determine: whether thickness of single layers can be used to accurately predict thickness and thermal resistance of multiple layer assemblies;…
Abstract
The purposes of this work were to determine: whether thickness of single layers can be used to accurately predict thickness and thermal resistance of multiple layer assemblies; and to identify variables affecting the total thickness (i.e. textile plus air layers) of bedding during simulated use. Thickness was determined when: materials were flat; and arranged over an infant manikin simulating use. Thermal resistance was measured using a guarded‐hotplate similar to that specified in ISO 11092:1993(E). During simulated use, the site of measurement, body position, tucking, and product type significantly affected thickness of bedding. Equations for predicting thickness and thermal resistance (dry) of multiple‐layer materials are described. While it was possible to predict thickness and thermal resistance of flat bedding from estimated values, extrapolation to bedding during simulated use was considered inappropriate, with significant differences of over 1,000 per cent.
In our study of job analysis used as a training instrument we started at the bottom of the spectrum, first treating the check‐list type of analysis and then, later, the procedural…
Abstract
In our study of job analysis used as a training instrument we started at the bottom of the spectrum, first treating the check‐list type of analysis and then, later, the procedural analysis which is presented by the training manual. This brings us now to the several forms of analysis which are collectively based on skills analysis and represent the most recent addition to the job analysis range
Mahanth Prasad, R.P. Yadav, V. Sahula and V.K. Khanna
The purpose of this paper is to help reduce power consumption by using platinum‐based microhotplate with different dielectric membranes SiO2 and Si3N4 for gas sensing…
Abstract
Purpose
The purpose of this paper is to help reduce power consumption by using platinum‐based microhotplate with different dielectric membranes SiO2 and Si3N4 for gas sensing applications, and to develop platinum lift‐off process using DC sputtering method for fabrication of platinum resistor.
Design/methodology/approach
Semiconductor gas sensors normally require high power consumption because of their elevated operating temperature 300‐600°C. Considering the thermal resistant and sensitive characteristics of metal platinum as well as heat and electricity insulating characteristics of SiO2, Si3N4 and combination of both, a kind of the Si‐substrate microhotplate was designed and simulated using ANSYS 10.0 tool. Thermal oxidation of Si wafer was carried out to get a 1.0 μm thick SiO2 layer. Pt deposition on oxidized silicon substrate by lift‐off was carried out using DC sputtering technique.
Findings
The platinum‐based microhotplate requires 31.3‐70.5 mW power to create the temperature 348‐752°C for gas sensing applications. The SiO2 membrane can operate the gas sensitive film at higher temperature than the Si3N4 and combination of both the membranes at same power consumption. The paper also presents the FEM simulation of different heating elements like nichrome and tantalum and its comparison to platinum for microhotplate applications.
Originality/value
Both the simulation and experimental work provides the low cost, high yield and repeatability in realization of microhotplate. The design and simulation work provides the better selection of heating elements and dielectric membranes. The developed experimental process provides the easy fabrication of platinum resistors using DC sputtering technique.
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Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…
Abstract
Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.
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Y.H. Chan, M.M. Arafat and A.S.M.A. Haseeb
The purpose of this paper is to investigate the effects of zinc (Zn) nanoparticles on the interfacial intermetallic compounds (IMCs) between Sn‐3.8Ag‐0.7Cu (SAC) solder and Cu…
Abstract
Purpose
The purpose of this paper is to investigate the effects of zinc (Zn) nanoparticles on the interfacial intermetallic compounds (IMCs) between Sn‐3.8Ag‐0.7Cu (SAC) solder and Cu substrate during multiple reflow.
Design/methodology/approach
The nanocomposite solders were prepared by manually mixing of SAC solder paste with varying amounts of Zn nanoparticles. The solder pastes were reflowed on a hotplate at 250°C for 45 s for up to six times. The actual Zn content after reflow was analyzed by inductively coupled plasma‐optical emission spectroscopy (ICP‐OES). The wetting behavior of the solders was characterized by analyzing the contact angles and spreading rates according to the Japanese Industrial Standard (JIS 23198‐3, 2003). The interfacial microstructure of the solder joints were investigated by field emission scanning electron microscope (FESEM) and energy dispersive X‐ray spectroscopy (EDAX).
Findings
It was found that upon the addition of 0.3 wt% Zn nanoparticles to the SAC solder, the growth of interfacial intermetallic compound (IMC) layers was retarded to a minimum value. Excessive amount of Zn nanoparticles (0.8 wt%) induced an additional IMC layer (Cu5Zn8) which increased the total IMC thickness and raising the reliability issue.
Originality/value
It is concluded that Zn nanoparticles undergo melting/reaction during reflow and impart their effect on the IMCs through alloying effects.
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Antonin Havelka and Zdeněk Ku˙s
This paper aims to investigate the comfort properties of modern functional clothing, such as moisture and heat transport. Transport properties are evaluated for real barrier…
Abstract
Purpose
This paper aims to investigate the comfort properties of modern functional clothing, such as moisture and heat transport. Transport properties are evaluated for real barrier membrane clothes for sport application, under real weather conditions in Middle Europe.
Design/methodology/approach
The different combination of functional clothing, with barrier membrane, were investigated under different temperatures and relative moistures inside and outside clothing layers. Water vapour permeability was measured under the steady‐state conditions, by sweating guarded‐hotplate test.
Findings
This paper describes the theoretical analysis of moisture transport, and its influence on thermal conductivity; the paper investigates various barrier fabrics for sport apparel, and their ranges of water vapour transport ability under real weather conditions.
Research limitations/implications
All received results are based on the transport of water vapour through a semi‐permeable membrane and are supposed to be conducted mainly within a process of diffusion.
Originality/value
This paper is focused on the theoretical analysis of transport by diffusion of water vapour through porous semi‐permeable barrier textile material, and evaluates the real possibilities for sport applications. The level of transport is limited and mainly depends on the difference of the partial pressures of water vapours outside and inside the porous clothing material.
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