scholarly journals The Study on Effects of Walking on the Thermal Properties of Clothing and Subjective Comfort

2020 ◽  
Vol 20 (3) ◽  
pp. 228-243
Author(s):  
Ivana Špelić ◽  
Dubravko Rogale ◽  
Alka Mihelić Bogdanić
Keyword(s):  
Thermal Properties ◽  
Thermal Insulation ◽  
Human Subjects ◽  
Three Dimensional ◽  
Climatic Conditions ◽  
Thermal Manikin ◽  
3D Cad ◽  
The Impact ◽  
Limiting Value ◽  
Insulation Value

AbstractFormer studies done by other authors investigated the first- and second-layered air gaps beneath the clothing garments. None of the previous studies reported multidisciplinary clothing design testing approach linking both the objective measuring methods and subjective responses, while testing the thermal properties linked to a microclimatic volume formed between the layers of garments forming the ensemble. Neither was determined the limiting value of the microclimatic volume for outerwear garments, after which the thermal insulation will start to decrease due to convection. By taking the advantage of the precise three-dimensional (3D) body scanning technology and reverse engineering 3D CAD tool, the volume of the microclimatic air layers formed under outerwear garments was determined to study the impact of the ensemble’s microclimatic volume on the overall insulation value, measured by means of the thermal manikin. The jacket with the smaller microclimatic volume provided 5.2–13.5% less insulation than wider jackets, while the ensembles with tighter jackets showed 0.74–1.9% less insulation in static and 0.9–2.7% more insulation in dynamic conditions, thus proving that the limiting value of the microclimatic volume is greater than previously reported for three-layered ensembles. The effective thermal insulation value was reduced in average by 20.98–25.34% between standing and moving manikins. The thermal manikins are designed for steady-state measurements and do not work well under transient conditions, so three human subjects were employed as evaluators of the clothing thermal quality. In cooler climatic conditions, the measured physiological parameters and subjects’ grades pointed to discomfort while wearing ensembles with tighter jackets.

The impact of structural solutions used in clothing protecting against cold on its thermal insulation

2016 ◽  
Vol 28 (6) ◽  
pp. 805-819 ◽  
Author(s):  
Anna Katarzyna Dabrowska
Keyword(s):  
Thermal Properties ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Design Methodology ◽  
Thermal Manikin ◽  
Content Type ◽  
Design Solutions ◽  
The Impact ◽  
Structural Solutions ◽  
Dominant Influence

Purpose The purpose of this paper is to analyze the impact of design solutions used in clothing on the thermal resistance of the material systems from which the clothing is made, design solutions used in clothing on its thermal insulation and clothing size on its thermal insulation properties. Design/methodology/approach This study involved laboratory tests of clothing protecting against cold and textile systems used in this type of garment using a “skin model” test stand and a thermal manikin. Findings Analysis of the results obtained from tests carried out showed that the design solutions used in a garment can model its local and overall insulation. It was found that using a bib in trousers has a dominant influence on the thermal properties of clothing. An important parameter is also the use of a hood, as well as the length of the jacket. No significant effect of other structural solutions, such as jacket fastening, pockets and reflective tapes, on the thermal performance of the clothing set was noted. Originality/value Although the reports available in the literature pay a lot of attention to the impact of the design of clothing protecting against cold on its thermal performance, most of the presented research results relate to the aspects of fit, whereas the analyses of the effects of other aspects of garment construction on thermal properties are lacking. Therefore, the analysis of the impact of design solutions used in clothing on its thermal insulation properties is a key original factor of this paper.

scholarly journals Thermal Behavior of Worsted Fabrics Produced from Different Yarn Spinning Systems

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800 ◽  
Author(s):  
Abolfazl Mirdehghan ◽  
Siamak Saharkhiz ◽  
Hooshang Nosraty
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Behavior ◽  
Thermal Insulation ◽  
Weft Yarn ◽  
Spun Yarn ◽  
Finishing Process ◽  
Yarn Structure ◽  
Fabric Structures ◽  
The Impact

This paper describes an experimental study of the impact of yarn structure on the thermal properties of worsted fabric. In this study, four different spun yarn structures (Solo, Siro, and single ply and two ply Ring) were woven into four fabric structures (Plain, Twill2/1, Twill2/2 and Basket2/2) and their thermal properties were studied. In addition, the thermal behavior of finished and unfinished samples was also evaluated. Results showed that the finishing process causes an increase in thermal conductivity and warmth to weight factor and a decrease in thermal insulation. Different spinning systems, also affect the thermal properties of the worsted fabrics. Samples with Siro yarns in the weft were found to have the highest thermal conductivity and those made from single ply weft yarn the lowest thermal conductivity. A relation between fabric thermal insulation and air permeability and thickness was also found.

scholarly journals Comparative Analysis of the Thermal Insulation of Multi-Layer Thermal Inserts in a Protective Jacket

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2672
Author(s):  
Dubravko Rogale ◽  
Goran Majstorović ◽  
Snježana Firšt Rogale
Keyword(s):  
Thermal Properties ◽  
Comparative Analysis ◽  
Thermal Insulation ◽  
Professional Services ◽  
Cold Weather ◽  
Complete Analysis ◽  
Thermal Manikin ◽  
Scientific Methods ◽  
Textile Materials ◽  
Measurement Results

This paper presents the measurement results of the thermal insulation of the outer shell, thermal inserts, and clothing systems, as well as a comparative analysis of the thermal insulation of multi-layer thermal inserts in a thermal jacket intended for professional services in cold weather. Detachable thermal inserts are made of double-faced, diamond-shaped quilted lining with different masses per unit area, and together with the jacket, they form clothing systems with different thermal properties. Tests of the thermal properties of clothing were performed on a thermal manikin. They showed that an increase in the mass of thermal insulation textile materials contributes to an increase in the thermal insulation properties of clothing and are insufficient for a complete analysis of the thermal properties of clothing. Therefore, for the first time, three new parameters of integration efficiency of the thermal insert, thermal insulation efficiency parameters, and efficiency parameters of the integration of the textile material integrated into the clothing system were introduced. Based on these parameters, it is possible to perform an effective and accurate comparative analysis of the thermal insulation of multi-layer thermal inserts in clothing. This makes it possible to apply exact scientific methods largely in the technical design of the thermal properties of integrated textile materials, instead of experience-based methods as in the past.

scholarly journals Characteristics of Specialised Firefighter Clothing Used in Poland – the Thermal Parameters

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 65-70
Author(s):  
Magdalena Młynarczyk
Keyword(s):  
Thermal Insulation ◽  
Protective Clothing ◽  
Thermal Parameters ◽  
Thermal Manikin ◽  
Test Results ◽  
Evaporative Resistance ◽  
Different Types ◽  
Local Thermal Insulation ◽  
Materials Used ◽  
The Impact

This paper describes the characteristic thermal parameters of firefighters’ personal protective clothing (FFPPC) used in Poland. The total thermal insulation and evaporative resistance of three different types of FFPPC were measured and used on a thermal manikin. Next, the results were compared. Based on the analyses and calculations of the test results, it was shown that FFPPC provides a barrier to the heat exchange between the user and the surrounding environment. Differences in the local thermal insulation can be triggered not only by the material used but they can also be attributable to clothes fitted on the manikin. The biggest differences can be noted on the segments forming part of the manikin’s trunk. No difference was found in the evaporative resistance between the clothes tested. In order to examine further the impact of the materials used on thermal parameters of protective clothing, it is necessary to carry out an analysis of the impact of individual layers.

scholarly journals Thermal Properties of Special New Generation Personal Protective Clothing for Firefighters-Rescuers

2021 ◽  
Vol 1 (80) ◽  
pp. 45-67
Author(s):  
Marzena Rachwał ◽  
Małgorzata Majder-Łopatka ◽  
Tomasz Węsierski ◽  
Artur Ankowski ◽  
Magdalena Młynarczyk ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermal Insulation ◽  
Protective Clothing ◽  
Body Shape ◽  
Thermal Protection ◽  
Thermal Manikin ◽  
Protective Equipment ◽  
Everyday Work ◽  
New Generation ◽  
Full Body

Every day, firefighters put their health and life at risk by saving people and their property not only during fires, but by being always ready during all kinds of unfortunate events. Therefore, they need special personal protective equipment, including protective clothing. The purpose of the study was to compare thermal properties of new (PROTON and SYRIUSZ) and old (US-03) personal protective clothing for firefighters. Measurements of thermal insulation (total, effective and local) were carried out using a full body shape thermal manikin Newton consisting of 34 segments, in which temperature and heat flux were controlled independently. Results of the total thermal insulation of the entire clothing reveal differences between all three models. The lowest values were noticed for the model PROTON with light and shorter jacket and the highest values of thermal insulation for the new model SYRIUSZ, indicating that this model protect the user against heat most effectively. New models of personal protective clothing for firefighters should be recommended for use in everyday work, because they are characterized by better parameters than the previous type of protective clothing, both in terms of thermal protection and mobility.

Thermal properties of thermal insulation chambers

2020 ◽  
pp. 004051752096671
Author(s):  
Dubravko Rogale ◽  
Snježana Firšt Rogale ◽  
Goran Majstorović ◽  
Goran Čubrić
Keyword(s):  
Thermal Properties ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Thermal Protection ◽  
Cold Weather ◽  
Thermal Manikin ◽  
Functional Dependencies ◽  
Starting Point ◽  
Wide Range ◽  
Intelligent Clothing

The paper presents the investigation of thermal properties of thermal insulation chambers as an actuator in intelligent clothing, having the property of automatically adjusting the thermal protection level. The chambers are designed to vary their thickness based on the pressure of the inflated air in them. The pressure value measured in the thermal insulation chamber gives the microcomputer information on the thickness of the chamber. The paper presents the investigation of the functional dependencies of changes in the thickness of the chambers on the air pressure in them and the thermal resistance depending on the thickness of the thermal insulation chamber. Experimental thermal insulation chambers were made and integrated into an intelligent article of clothing and filled with air of 0–50 mbar, whereby chamber thicknesses of 0–25 mm were measured. Next, thermal resistance of 0.1876–0.5022 m2 k/W was measured on the thermal manikin. It was found that the ratio of thermal insulation of non-activated to maximally activated chambers was 1:2.7. Research has shown good results for the area where intelligent clothing can automatically adjust its thermal insulation properties. The technical systems described represent a suitable basis for experiments and scientific research during the introduction of intelligent clothing with active thermal protection into human life. The third-generation prototype shows very good properties from the aspect of automatic control of thermal protection in intelligent clothing. This forms the basis for further research. Cold protection has always been carried out by wearing garments with higher or lower thermal protection as well as wearing multiple layers of clothing. The conceptual starting point of the development of intelligent clothing is the development of an adaptive insulation layer with changeable thickness in the form of thermal insulation chambers filled with air. In this way, layered clothing as well as the use of several clothing layers can be avoided. Thus, one intelligent article of clothing regulating its thermal insulation properties can be used in a wide range of cold weather in the environment of the wearer.

scholarly journals Novel biological implication of a strictly monomorphic GCC repeat in the human PRKACB gene

2021 ◽  
Author(s):  
Safoura Khamse ◽  
Zahra Jafarian ◽  
Ali Bozorgmehr ◽  
Mostafa Tavakoli ◽  
Hossein Afshar Iranian ◽  
...  
Keyword(s):  
Late Onset ◽  
Human Subjects ◽  
Three Dimensional ◽  
Dna Structure ◽  
Dimensional Structure ◽  
Protein Coding ◽  
Three Dimensional Structure ◽  
Significant Divergence ◽  
The Impact ◽  
The Brain

Abstract Across human protein-coding genes, PRKACB (Protein Kinase CAMP-Activated Catalytic Subunit Beta) contains one of the longest GCC-repeats, and is predominantly expressed in the brain. Here we studied this STR in 300 human subjects, consisting of late-onset neurocognitive disorder (NCD) (N = 150) and controls (N = 150). We also studied the impact of this STR on the three-dimensional structure of DNA. While the PRKACB GCC-STR was strictly monomorphic at 7-repeats, we detected two 7/8 genotypes only in the NCD group. In comparison to all other lengths, (GCC)7 had the least effect on the three-dimensional structure of DNA, evidenced by minimal divergence between 0 and 7-repeats (divergence score = 0.04) and significant divergence between 0 and 8 repeats (divergence score = 0.50). A similar inert effect to the GCC-repeat was not detected in other classes of STRs such as GA and CA repeats. In conclusion, we report monomorphism of an exceptionally long GCC repeat in the PRKACB gene in human, its inert effect on DNA structure, and divergence in two cases of late-onset NCD. This is the first indication of natural selection for an exceptionally long monomorphic GCC-repeat, which probably evolved to function as an “epigenetic knob”, without changing the regional DNA structure.

Artificial neural networks for prediction of local thermal insulation of clothing protecting against cold

2018 ◽  
Vol 30 (1) ◽  
pp. 82-100
Author(s):  
Anna Katarzyna Dabrowska
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Thermal Insulation ◽  
Thermal Manikin ◽  
Content Type ◽  
Artificial Neural ◽  
Local Thermal Insulation ◽  
High Level ◽  
Hands And Feet ◽  
The Impact

Purpose The purpose of this paper is to develop artificial neural networks (ANNs) allowing us to simulate the local thermal insulation of clothing protecting against cold on a basis of the characteristics of materials and design solutions used. Design/methodology/approach For this purpose, laboratory tests of thermal insulation of clothing protecting against cold as well as thermal resistance of textile systems used in the clothing were performed. These tests were conducted with a use of thermal manikin and so-called skin model, respectively. On a basis of results gathered, 12 ANNs were developed that correspond to each thermal manikin’s segment besides hands and feet which are not covered by protective clothing. Findings In order to obtain high level of simulations, optimization measures for the developed ANNs were introduced. Finally, conducted validation indicated a very high correlation (above 0.95) between theoretical and experimental results, as well as a low error of the simulations (max 8 percent). Originality/value The literature reports addressing the problem of modeling thermal insulation of clothing focus mainly on the impact of the degree of fit and the velocity of air movement on thermal insulation properties, whereas reports dedicated to modeling the impact of the construction of clothing protecting against cold as well as of diverse material systems used within one design of clothing on its thermal insulation are scarce.

scholarly journals TESTING THE SUITABILITY OF THE EXTRUDED POLYSTYRENE (STYRODUR) APPLICATION IN THE TRACK SUBSTRUCTURE

2020 ◽  
Vol 60 (3) ◽  
pp. 243-251
Author(s):  
Libor Ižvolt ◽  
Peter Dobeš ◽  
Martin Mečár
Keyword(s):  
Thermal Insulation ◽  
Climatic Conditions ◽  
Deformation Resistance ◽  
Experimental Measurements ◽  
Deformation Properties ◽  
Crushed Aggregate ◽  
Standard Structure ◽  
Track Substructure ◽  
The Impact ◽  
Universal Application

Extruded polystyrene (XPS) and its excellent thermal insulation properties have been known for over 60 years. Due to its thermal, mechanical, but also deformation properties, XPS has a universal application, not only in the construction industry. This paper presents the results of the first series of experimental measurements of the deformation resistance of the sub-ballast layers with a built-in XPS thermal insulation layer and the sub-ballast layers with a standard structure (crushed aggregate sub-ballast layer). The aim of the first series of experimental measurements was to determine the impact of placing the XPS layer at the subgrade surface level (deformation resistance of subgrade surface E0 = approx. 10MPa or 30MPa) on the deformation resistance of the sub-ballast layers and then to determine the necessary thickness of the sub-ballast layer in relation to the required deformation resistance at the sub-ballast upper surface. Experimental measurements carried out so far show that the application of XPS boards in the sub-ballast layers has almost no or minimal effect on its deformation resistance. Since XPS boards have significantly better thermal technical properties compared to crushed aggregate, considerable savings of this material can be achieved in areas with unfavorable climatic conditions (high values of air frost index).

scholarly journals Hygrothermal Analysis And Prediction Of Long-Term Thermal Performance Of Aerogel-Enhanced Superinsulation Products

2021 ◽  
Author(s):  
Hamideh (Roya) Nosrati
Keyword(s):  
Thermal Properties ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Climatic Factors ◽  
Accelerated Aging ◽  
Climatic Conditions ◽  
Aging Effects ◽  
Insulating Materials ◽  
Hygrothermal Analysis ◽  
The Impact

Aerogel-enhanced insulating materials provide significantly higher thermal resistance per unit of thickness compared to conventional insulating materials. These superinsulation materials are relatively new in the construction industry, and their thermal properties under different hygric conditions and their durability are still unknown. In this study, the main characteristics of a variety of aerogel-based materials under different climatic conditions were studied. Furthermore, the samples underwent accelerated aging tests, and the impact of aging on the thermal performance of aerogel-based products was investigated. The results showed that the thermal properties of aerogel-based products are affected by moisture content and their thermal resistance degraded under extreme humidity conditions. The analysis of the aging effects showed that aerogel-based products would maintain their superior thermal performance over time. The average increase in the thermal conductivity (compared to the pristine condition) was below 10% after the equivalent of twenty years of aging under various climatic factors.

Sign in / Sign up

Export Citation Format

Share Document