パンティストッキング布の通気性

The aim of our work was to establish whether very good to excellent UV (ultraviolet) protective properties of fabrics can be obtained through a suitable fabric construction and yarn colour, at the same time ensuring suitable air permeability. For this purpose, six different fabric structures divided into three groups were employed. The samples were made in blue and red combinations of weft with different sequences and proportions between the upper and lower weave threads. A comparison of different fabric structures and colours was attempted to enable the assessment of the impact of the mentioned parameters on both, UV protective properties and air permeability of fabrics. The analysis comprised the investigation of physical and permeability properties, as well as the colour measurements on twelve different cotton fabrics. The research indicated excellent UV protection (>60) in all samples. UV protection depended on their construction and in a sufficiently closed structure, also on the colour of the used yarn. There was no significant difference between the samples in blue and red. In addition to excellent UV protection, four samples (one double-weft and three double fabrics) also demonstrated very high air permeability, which was 3–5 times higher than in the one-layer sample, which demonstrated the best UV protective properties. The research has shown that fabrics with a very high ultraviolet protective factor value and good air permeability can be made by using a suitable construction and yarn colours that sufficiently absorb UV light; the latter being particularly important for light summer cotton clothes.

In this study more effective methods of applying a fluorochemical finish to relatively inexpensive melt blown/spunbond (MB/SB) nonwoven laminates developed in the Textiles and Nonwovens Development Center (TANDEC) at The University of Tennessee, Knoxville (UTK) were investigated with respect to improved performance and lower cost. The two possible end-uses for the MB/SB laminates are operating room drapes and gowns and apparel for agricultural workers, such as, pesticide applicators. In addition to comparing finishing techniques, the thermal bonding sequence of a MB/SB laminate before and after finishing also was studied to determine the effects on repellency, barrier properties, laminate bonding strength, air permeability and hand. Polypropylene melt blown webs produced on the 20-inch (0.51 m) Exxon melt blown pilot line at UTK were laminated with an experimental point bonded spunbond polypropylene fabric. Polypropylene melt blown and spunbond laminate samples were thermally bonded with a smooth roll calender both before and after fluorochemical (FC) finishing by the more conventional padding technique and by two low wet pickup methods, foam finishing and kiss roll applications. Repellency (oil, alcohol and water repellency), barrier properties (water impact resistance and air permeability), and bonding strengths were examined. Surprisingly, the MB/SB laminates, which were thermally bonded prior to finishing, picked up substantially less finish due to decreased porosity, but had much improved oil and alcohol repellency. The foam finished laminates had the highest oil and alcohol repellency values followed by those prepared by kiss roll and finally the padding techniques. Although all of the finished MB/SB laminates had excellent water spray ratings and water impact penetration resistance (due to the barrier properties of the melt blown component), the key to oil and alcohol repellency appears to be the concentration of FC finish deposited on the outer surface of the laminate. As would be expected, the thermally bonded laminates had lower air permeability, as compared to the unbonded laminates. The melt blown and the spunbond components separately had appreciably higher air permeability. However, the air permeability values of the MB/SB laminates, which were thermally bonded before FC finishing were generally greater than a slightly lower weight commercial spunbond/melt blown/spunbond (SMS) fabric, which had been thermally point bonded. Laminate bonding strengths were much lower than the commercial point bonded SMS fabric, but were believed to be suitable for some protective clothing applications.

The influence of gas diffusion layer (GDL) design parameters on the performance of a polymer electrolyte fuel cell (PEFC) was evaluated using a test apparatus in which the clamp pressure on the cell could be accurately controlled. The PEFC performance varies significantly depending on the humidity of the supplied gas. Under moderate humidity, the PEFC performance is enhanced when using an untreated GDL with high air permeability. Under high humidity, improved performance is achieved using a GDL with PTFE hydrophobic treatment. A microporous layer (MPL) coated GDL significantly reduces flooding on the electrode, resulting in a decrease in the concentration overpotential. This enhances the PEFC performance at high current densities. A substrate with high air permeability for the MPL coated GDL enhances the ability of the MPL to prevent flooding. Under low humidity, the MPL is also effective to prevent drying-up of the membrane electrode assembly (MEA), resulting in enhanced performance. A substrate with low air permeability for the MPL coated GDL is effective for the prevention of drying-up.

Great durability problems are being found in concrete structures related to the penetrability of aggressive agents through the concrete (ie. chloride penetration, sulphate attack, carbonation, freezing and thawing, and so on). Air permeability coefficient is used as an effective tool to estimate the potential durability of concrete structures due to its direct relation with the microstructure and the moisture content. This paper discusses the effect of the aggregate grading and water/cement ratio on the air permeability coefficient. An aggregate grading with more sand than coarse aggregates has resulted more beneficial from the point of view of concrete air permeability. This fact can be attributed to a denser skeleton formed by the finer aggregates. With fine aggregates, the higher water/cement ratio, the lower air permeability. However, the contrary was found with coarse aggregates. Overall, a temperature increase from 20 °C to 60 °C during preconditioning led to a Dair increase of 40–80%.

Purpose – The purpose of this investigation was to measure the changes in effective thermal insulation caused by three different types of outer garment ventilation features (chest zips, back zips and pit zips) when combined with either a high or low air permeability insulating layer. Design/methodology/approach – The measurements in this investigation were made with a thermal manikin and with a 26 zone thermal torso. Measurements were made at two air flow speeds with each manikin; the different air flow characteristics for each manikin allowed investigation of how ventilation features interact with different air flow distributions. Findings – It was established in this study that high permeability insulation increases the efficacy of ventilation features by an average of 7 per cent at the low wind speed and 10 per cent at the high wind speed. No particular ventilation feature was found to be consistently the most effective; the data suggest that garment openings should simply be located in well-ventilated areas. Originality/value – This investigation analysed the ventilation characteristics of protective clothing ensembles with different ventilation features, allowing designers to create more comfortable clothing for work and leisure activities.

The performance of air sparging systems, as measured by the predicted region of airflow, was investigated by conducting numerical simulations with a multiphase modeling program (TETRAD). The simulations employed standard two‐phase flow theory, and included pressure‐dependent calculations of the compressibility of water and air. Simulations tested the response of air sparging systems to variations in geological properties (intrinsic permeability and anisotropy of permeability) as well as different injection scenarios (depth, pressure, and rate of injection).Three stages of flow behavior are predicted following initiation of air injection. These are: (1) an initial transient period of growth in the lateral and vertical limits of airflow (expansion stage); (2) a second transient period of reduction in the lateral limits of airflow (collapse stage); and (3) a steady‐state stage, during which the system remains static as long as injection parameters do not change. In homogeneous media the geometry of the region of airflow changes from a teardrop‐or bell‐shaped configuration to a shape that is roughly conical during the expansion stage. During the collapse stage, air is preferentially diverted to established regions of high effective air permeability, and ground water resaturates the remainder of the original region of influence. For pilot testing it is important to realize that measurements of the lateral extent of airflow expansion and collapse stages can be misleading because they will differ from the limits established at steady‐state. The time required for a particular system to progress through the transient stages and establish steady‐state behavior can vary from hours to years, and is dependent on the permeability structure of the aquifer, injection depth, and injection rate. Under homogeneous conditions the maximum width of the region of airflow attained during the transient expansion stage was substantially greater than the width attained at steady‐state.The width of the steady‐state region of airflow is significantly affected by all the variables investigated, except injection depth, which appears to primarily influence the transient behavior. The simulations further show that the vertical permeability and anisotropy of the aquifer are very important variables, and warrant routine assessment during design of sparge systems. Simulation of heterogeneous media demonstrate that complex airflow patterns will occur as a result of air ponding beneath, and flow around, zones of low air permeability.

Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air‐phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the Klinkenberg effect, variations in air density and viscosity that result from temperature fluctuations in the unsaturated zone and the possibility of inducing water movement during the pneumatic test. An analysis of these complicating factors reveals that, when induced water movement can be neglected, a linear version of the airflow equation can provide an appropriate approximation for the purpose of determining air‐phase permeability. Two analytical solutions for steady state, two‐dimensional, axisymmetric airflow to a single well partially screened in the unsaturated zone are developed. One solution applies where there is a stratum of relatively low air permeability, separating the stratum in which the well is completed, from the atmosphere. The other solution applies where there is no separating stratum between the domain and atmosphere. In both situations the water table forms the lower horizontal boundary. Applications of both solutions to determine air permeability from data collected during pneumatic tests are presented.

Multilayer three-dimensional (3D) fabrics are gaining importance due to their unique properties, which are significantly influenced by the interlocking pattern and govern their end-use applications, particularly in protective textiles requiring higher through-the-thickness mechanical characteristics. This research focuses on developing 3D woven structures with novel orthogonal through-the-thickness interlocking patterns: warp interlocked (WP-IL), weft interlocked (WT-IL), and hybrid interlocked (HB-IL) by using warp and weft yarns simultaneously for interlocking fabric layers. Various performance characteristics, including air permeability, thermal conductivity, compression resistance, bending rigidity, tensile strength, and puncture resistance, were evaluated to assess the influence of fabric structure. Statistical analysis using One-way ANOVA was conducted to determine the significance of the interlocking pattern on these properties. The results indicate that weft interlock structures exhibit the highest air permeability due to their greater porosity, whereas hybrid interlock and warp interlock structures show 20.7% and 18% lower air permeability, respectively, due to their reduced structural porosity. Thermal conductivity results suggest no significant differences in insulation properties among the structures. Hybrid interlock fabrics demonstrate superior compression resistance and tensile strength, with 26.2% higher tensile strength than warp interlock structures and 12.3% higher than weft interlock structures in the warp direction, owing to the balanced distribution of binding yarns. In contrast, warp interlock structures exhibit the lowest bending rigidity in the weft direction, making them more flexible. Additionally, hybrid interlock structures provide the highest puncture resistance, while weft interlock structures show the lowest resistance due to their increased porosity. These findings highlight the critical role of fabric architecture in determining both comfort and mechanical properties, providing valuable insights for selecting optimal 3D woven structures in applications requiring specific performance attributes.

Daily monitoring of internal tissues with shape-conformable and breathable ultrasound (US) imaging probes is promising for early detection of diseases. In recent years, textile substrates are widely used for wearable devices since they satisfy both conformability and breathability. However, it is not currently possible to use textile substrates for US probes due to the reflection or attenuation of US waves at the air gaps in the textiles. In this paper, we fabricated a shape-conformable and breathable US imaging probe by sandwiching the US elements between two woven polyester textiles on which copper electrodes were formed through electroless plating. The air gaps between the fibers at the electrode parts were filled with copper, allowing for high penetration of US waves. On the other hand, the non-electrode parts retain air gaps, leading to high breathability. The fabricated textile-based probe showed low flexural rigidity (0.066 × 10−4 N m2 m−1) and high air permeability (11.7 cm3 cm−2 s−1). Human neck imaging demonstrated the ability of the probe to monitor the pulsation of the common carotid artery and change in the internal jugular vein diameter, which led to the early detection of health issues such as arteriosclerosis and dehydration, and the capability of stable 24-hour monitoring.

Soil productivity and other soil functions are dependent on processes in the untilled subsoil. Undisturbed soil cores were collected at the 0.3- to 0.4-m depth from a heavy clay soil in Finland subjected to a single heavy traffic event by agricultural machinery three decades before sampling. Untrafficked control plots were used as a reference. Computed tomography (CT) scanning was performed on soil cores at a field-sampled field capacity water content. Gas diffusion and air permeability were measured when the soil cores were drained to −1000 hPa matric potential (air permeability also at −100 and −300 hPa). The air-filled pore space was measured with an air pycnometer and also calculated from mass balance and CT data. Gas diffusion and air permeability were also measured on a straight model tube and on autoclaved aerated concrete. The compaction treatment had not influenced soil total porosity but had significantly lowered the volume fraction of air-filled macropores at the matric potentials investigated. The compacted soil displayed significantly lower air permeability, while gas diffusivity was not affected. Our analyses indicate that this was due to a compaction-induced reduction in the cross-sectional area of vertical, arterial macropores and in the volume of marginal pores branching from these vertical pores. We observed non-Darcian air flow during air permeability measurements and thus suggest the use of a nonlinear regression technique based on measurements at several pressure differences to arrive at true Darcian air permeability. The tests on artificial materials supported the conclusions that the dominating pores in this clayey subsoil are nearly straight, vertical macropores.

Micromorphological and selected physical properties of a moldboard-plowed soil with and without residue cover

The use of textile science and innovative approaches in the development and manufacturing of multifunctional fabrics for sports bras has continuously grown in the last decades, contributing to female well-being and health. The fabrics used for sports bras must be lightweight and have good heat and moisture management properties. A sports bra must provide appropriate stabilization, as the most important and original functionality, while providing optimal thermal comfort. In this work, we examined basic fabric properties influencing the key functionalities, stabilization, and drying. Besides properties such as mass, thickness, water vapor permeability, air permeability, and relative porosity, thermal comfort (water uptake and drying) and mechanical properties (stabilization and support) were investigated. Multiple-linear regression statistical analysis was conducted to identify the most relevant variables and fabric characteristics for stabilization and drying. In addition, a “five-point” benchmarking and ranking system was established for performance assessment of the investigated knitted fabrics. With the proposed approach, we were able to identify the most suitable fabric from a set of benchmarking materials. This fabric exhibited a quick drying time of 16 minutes, along with high air permeability (312 mm/s), excellent moisture management, and very good dynamic elastic recovery (89%) and support. We successfully identified key fabric properties that define fabric drying and stabilization performance by applying models based on Multiple-linear regression. This provides the basis for the informed selection of fabrics for the systematic development of sports bras.

Capacitive pressure sensors received significant attention in line with advancements in wearable electronics. However, in the era of the wearable electronics, fabricated sensors fail to fulfill the absolute requirements. Significant portion of the previously reported capacitive pressure sensors suffer from excessive weight, lack of air permeability, and washing stability due to the use of separate electrode layers. A low‐cost, lightweight, parallel plate capacitive sensor with a unique seamless monolithic design that allows sensors to circumvent aforementioned problems is hereby demonstrated. The seamless monolithic capacitive sensor (MCS) with a density of as low as 10.78 mg cm−3 is fabricated using 3D masking technique on a commercially available melamine foam with silver nanowire electrodes and a protective thin layer of polydimethylsiloxane coating. In addition to its unique design, the MCSs show high sensitivity (up to 1.285 kPa–1), fast response/recovery time (18 ms/53 ms), very low‐pressure sensing ability (0.5 Pa) with ultra‐high mechanical (42 000 cycles), and washing stabilities (10 cycles) along with high air permeability. Moreover, finite element analysis simulations are conducted to reveal the deformation mechanism differences between the monolithic and classical design. Finally, in order to demonstrate their true potential, fabricated MCSs are utilized in real‐time body motion monitoring, word and proximity detection.

Summary Pinus contorta, logs with occluded cankers caused by the pathogen Gremmeniella abietina, as well as logs from unaffected trees were sampled from a 23‐year‐old plantation in Sweden and compared in terms of their paper properties. Damaged wood gave kraft pulp with poor paper properties: it required a larger amount of beating energy and resulted in paper with low tear strength, air permeability, tensile stiffness, burst strength, and poor light‐scattering properties. However, small amounts of damaged wood mixed in with a large amount of healthy wood can pass almost unnoticed. The use of trees with a larger content of damaged wood will lead to serious processing problems and give a pulp with poor paper properties. Thus, wood damaged by Gremmeniella should be sorted out and classed as low‐grade raw material.

The Fergana valley is a region critically important for food safety in Central Asia. The human-altered soils in Fergana are considered a key component of the transboundary region between sub-boreal and sub-tropic climatic zones. As the results of the investigation of irrigated chloride-sulfate saline soils near the surface showed the deep petrocalcic and petrosalic horizons at various depths with extremely low water and air permeability. The chemical, pedogeochemical, and biogeochemical properties of soils, the content of macroelements, trace elements, lanthanides and radionuclides, and the general geochemical characteristics of desert zone soils were investigated and determined. The background contents of the mentioned elements were recognized. The irragic, salic, gleyic, and gypsic horizons in soils were identified by WRB 2015. They can be used as reference horizons for biogeochemical studies and soil management activities. The irragic, gleyic, carbonate-gypsum horizons, evaporation, oxygenic, and other geochemical barriers were studied and revealed. The processes of accumulation, migration, and differentiation of chemical elements in solum as well as in parent materials occur with the joint effects of exogenous, endopedogenic, and artificial factors. These fluxes of elements, in turn, are affected by the nature of soils and parent materials. In this process, unexplored elements form only scattering fluxes. During the vegetation season, as well as the leaching period, considering the various horizons features will help to save significant amounts of irrigation water.