The stored energy provided by the fabric assemblies will greatly influence the thermal protection performance (TPP) of firefighters’ protective clothing under low-intensity radiation heat exposure. In this study, two test methods, namely radiant protective performance (RPP) and stored energy test (SET), were used to investigate the TPP of the fabric assemblies. The results indicated that TSET value was lower than TRPP value because of the release of the stored energy in the fabric assemblies after heat exposure. Increasing the fabric layer numbers, air gap between the fabric assemblies would increase the time of TRPP and TSET, indicating that the thermal stored energy weakened the TPP of the firefighters’ protective clothing. Moreover, the TRPP and TSET of the fabric system would be increased when the moisture barrier was cut in the fabric combination system. These findings suggested that stored energy should be considered in analyzing the TPP of fabric assemblies..
This article presents the results of research carried out based on consumer assessment of the quality of clothing using sensory analysis. The study aimed to determine the role of the brand and information about it in assessing product quality and identify the quality parameters that distinguish brands of a similar quality level. An attempt was also made to classify popular brands of clothing available on the Polish market based on the parameters that determine their quality. A significant impact of the brand name on the sensory assessment of clothes’ quality has been reported. The study has shown that assessors attribute higher rating values to quality features when they know the product brand; moreover, the brand and its information shortens the assessment time, which may suggest that it simplifies and facilitates consumers’ decision-making process. The result analysis has led to the identification of three groups of the factors determining the quality of clothing products: fabric composition, workmanship, and all other variables. It has also led to the separation of three clusters, characterized by different levels of product quality, for which sets of features distinguishing a given category were determined.
Developed by French mathematician Augustin-Louis Cauchy, the classical theory of elasticity is the starting point to show the value and the physical reality of quaternions. The classical balance equations for the isotropic, elastic crystal, demonstrate the usefulness of quaternions. The family of wave equations and the diffusion equation are a straightforward consequence of the quaternion representation of the Cauchy model of the elastic solid. Using the quaternion algebra, we present the derivation of the quaternion form of the multiple wave equations. The fundamental consequences of all derived equations and relations for physics, chemistry, and future prospects are presented.
Young ballet dancers are at risk of health issues associated with altered nutritional status and of relative energy deficiency in sport compared to the general population.
To evaluate the nutritional status and body composition in ballet dancers.
Materials and methods
The study group consisted of 40 young ballet dancers (mean age 19.97 years). Height and weight were measured and body mass index was calculated in all subjects (mean BMI value 19.79 kg/m2, SD: 2.051). Body composition was estimated using the bioelectrical impedance method.
The dancers’ fat-free mass was 47.33 kg (SD: 5.064) and, on the average, body fat represented the 15.92% (SD: 16.91) of their body weight.
Ballet dancers, who usually show significantly lower BMI values compared to the general population, also displayed body fat values under the suggested range. Some screening for altered nutritional status should be performed. In addition, education programs should be recommended in young ballet dancers, in order to inform about energy and nutrition requirements for health and training and to prevent malnutrition-related problems.
There is a strong need for a non-invasive measurement technique that is capable of accurately identifying the physiological condition change or heterogeneity of subcutaneous adipose tissue (SAT) by localizing the abnormalities within the compartment. This paper aims to investigate the feasibility of Electrical Impedance Tomography (EIT) to assess the interstitial fluid in subcutaneous adipose tissue as an enhancement method of bioelectrical impedance spectroscopy (BIS). Here, we demonstrate the preliminary result of EIT with a wearable 16 electrodes sensor. The image-based reference EIT with fat weighted threshold method is proposed. In order to evaluate the performance of our novel method, a physiological swelling experiment is conducted, and Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is also applied as a comparison with EIT results. The experimental results showed that the proposed method was able to distinguish the physiological swelling condition and effectively to remove the unexpected background noise. Furthermore, the conductivity variation in the subcutaneous layer had a good correlation with extracellular water volume change from MFBIA data; the correlation coefficient R2 = 0.927. It is concluded that the proposed method provides a significant prospect for SAT assessment.
Compression bandage (CB) as a porous material should provide both graduated pressure and thermal comfort properties to enable air permeability, heat transfer, and liquid perspiration out of the human body. The main factors affecting thermal comfort properties are the temperature difference between environment and skin, yarns’ structure and material, fabric thickness, porosity, areal density, number of fabric layers, trapped air, and fabric structure. Thermal resistance (Rct) and water vapor resistance (Ret) are evaluated for four types of woven CBs. All bandage types were applied at the range of extension (10–80%) using both two- and three-layer bandaging on thermal foot model (TFM). Rct values are compared with measured results by the Alambeta instrument, whereas Ret test is performed on the Permetest device. Thermal resistance is significantly decreased when increasing the bandage extension from 10 to 40%, then it is slightly increased by increasing the extension from 40 to 60%, after that it is decreased especially at 80% extension due to lower bandage thickness and higher compression.
Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics.
In this paper, an industrial case study comparing the use of different needles in the production of hems in towels is presented. The study aims to assess the sewability of the fabrics, quantified by needle penetration forces. The market offers an interesting range of options for the needle, regarding the geometry of the needle point, surface finishing, and sizes. However, in practice, the choice is difficult, namely due to the lack of quantitative data that may support the empirical evaluation made by the sewing technicians. The work aims to assess how the needle type and size relate to the resulting needle penetration forces. Three terry fabric structures, produced by a home textiles manufacturer, were tested using needles of different sizes, points, and coatings. Needle penetration forces were measured on a sewability tester prototype, previously designed and developed, based on an instrumented overedge sewing machine. It was found that needle penetration forces present very significant differences with small size increments, needle coating also influences forces significantly, and different needle points produce only slight differences, significant only on some of the fabrics that were tested.
This research investigates the compressive property of a novel composite based on a weft-knitted auxetic tube subjected to a quasi-static compression test. In order to maximize the influence of the fiber content on the compression test, a Kevlar yarn was used in knitting the tubular samples using three different auxetic arrow-head structures (i.e. 4 × 4, 6 × 6 and 8 × 8 structure). A quasi-static compression test was conducted under two different impact loading speeds (i.e. 5 mm/min and 15 mm/min loading speed). The results indicate that the energy absorption (EA) property of the auxetic composite is highly influenced by the auxeticity of the knitted tubular fabric.