Effect of surface treatment and knit structure on comfort properties of wool fabrics

The comfort properties of the pique and single jersey knitted wool fabrics were investigated using the Wool ComfortMeter (WCM). The fabrics were knitted in three cover factors and treated with either plasma or a silicone softening agent and were compared with untreated fabrics. Plasma treatment did not show significant effects on the comfort value. However, silicone polymer significantly reduced WCM values suggesting that the silicone coating reduced the number of protruding fibres on the fabric surface. Regardless of treatment used, pique fabrics showed a lower WCM value, and therefore were perceived to be more comfortable than the single jersey structure. While the effect of cover factor was not significant, in fitted model to predict the WCM value of fabrics, mass/unit area and fabric thickness were significant predictors along with fabric structure and finishing treatment.

Wear attributes of cashmere single jersey knitted fabrics blended with high and low crimp superfine merino wool

In a replicated experiment, we investigated the impact of cashmere in blends with superfine wools on the wear attributes of single jersey knitted fabrics. We also investigated the relative performance of low crimp/low fiber curvature superfine wool when compared with cashmere and also when compared with traditional high crimp/high fiber curvature superfine wool in pure and blended knitted fabrics. Wool type, blend ratio and fabric structure affected fabric air permeability, resistance to pilling and change in appearance, relaxation shrinkage, hygral expansion, and dimensional stability during laundering. The responses to variation in fiber crimp were much greater than previously reported. The fabric properties of low crimp wool differed significantly from those made from high crimp wool, and low crimp wool fabric properties differed significantly from, but were closer to, the fabric properties of cashmere, compared with high curvature wool.

The effect of humidity and temperature on Wool Comfort Meter assessment of single jersey wool fabrics

The Wool ComfortMeter provides an objective measurement of the fabric-evoked prickle discomfort rating provided by wearers. This work aimed to quantify the sensitivity of the Wool ComfortMeter over a range of different temperature and humidity conditions to determine the recommended test conditions for its operation. The design was: three temperatures (notionally 20, 25 and 30°C) at three relative humidities (RHs, notionally 50, 65 and 80%) each with two replicates, using six different wool single jersey knits (mean fibre diameter 19.5–27.0 µm). As it was difficult to achieve exactly some of the extreme combinations of temperature and RH, some combinations were repeated, providing a total of 23 different assessment conditions. Data were analysed using restricted maximum likelihood mixed model analysis. The best fixed model included RH, RH2, temperature and the interaction of temperature and RH, accounting for 95% of the variation in Wool ComfortMeter readings. Wool ComfortMeter values were almost constant at 55–60% RH. Generally, the Wool ComfortMeter value reduced with increasing RH > 60% at temperatures of 25°C and 28.5°C as the regain of the fabric increased. However, at 20°C little change was detected as RH was increased from 50 to 80% as there were only small changes in fabric regain. The observed effects were in a good agreement with existing knowledge on the effect of regain on the mechanical properties of wool fibre. Wool ComfortMeter is best operated under standard conditions for textile testing of 65% RH and 20°C.

Multiple identification and risks : examination of peer factors across multiracial and single-race youth

Multiracial youth are thought to be more vulnerable to peer-related risk factors than are single-race youth. However, there have been surprisingly few well-designed studies on this topic. This study empirically investigated the extent to which multiracial youth are at higher risk for peer influenced problem behavior. Data are from a representative and longitudinal sample of youth from Washington State (N = 1,760, mean age = 14.13, 50.9% girls). Of those in the sample, 225 youth self-identified as multiracial (12.8%), 1,259 as White (71.5%), 152 as Latino (8.6%), and 124 as Asian American (7.1%). Results show that multiracial youth have higher rates of violence and alcohol use than Whites and more marijuana use than Asian Americans. Higher levels of socioeconomic disadvantage and single-parent family status partly explained the higher rates of problem behaviors among multiracial youth. Peer risk factors of substance-using or antisocial friends were higher for multiracial youth than Whites, even after socioeconomic variables were accounted for, demonstrating a higher rate of peer risks among multiracial youth. The number of substance-using friends was the most consistently significant correlate and predictor of problems and was highest among multiracial youth. However, interaction tests did not provide consistent evidence of a stronger influence of peer risks among multiracial youth. Findings underscore the importance of a differentiated understanding of vulnerability in order to better target prevention and intervention efforts as well as the need for further research that can help identify and explain the unique experiences and vulnerabilities of multiracial youth.

Cryo-electron microscopy and single molecule fluorescent microscopy detect CD4 receptor induced HIV size expansion prior to cell entry

Viruses are often thought to have static structure, and they only remodel after the viruses have entered target cells. Here, we detected a size expansion of virus particles prior to viral entry using cryo-electron microscopy (cryo-EM) and single molecule fluorescence imaging. HIV expanded both under cell-free conditions with soluble receptor CD4 (sCD4) targeting the CD4 binding site on the HIV-1 envelope protein (Env) and when HIV binds to receptor on cellular membrane. We have shown that the HIV Env is needed to facilitate receptor induced virus size expansions, showing that the 'lynchpin' for size expansion is highly specific. We demonstrate that the size expansion required maturation of HIV and an internal capsid core with wild type stability, suggesting that different HIV compartments are linked and are involved in remodelling. Our work reveals a previously unknown event in HIV entry, and we propose that this pre-entry priming process enables HIV particles to facilitate the subsequent steps in infection.

Self-assembly of ultrathin gold nanowires and single walled carbon nanotubes as a highly sensitive substrate for surface enhanced Raman spectroscopy

Here we report self-assembly of ultrathin gold nanowires and single-walled carbon nanotubes with an ultrahigh aspect ratio as a highly sensitive substrate for surface enhanced Raman spectroscopy. And we demonstrated that the hybrids were especially efficient in adsorption of aromatic molecules such as 4-mercaptobenzoic acid and the hybrids materials could be used as a novel platform for trace level detection in the verification of paper notes through the Raman enhancement technique.

A comparison of pilling results tested with the ICI pill box and a new perspex™ pill box

Identical single jersey wool knit fabrics produced inconsistent results when tested on the same type of ICI pill box in 4 independence testing laboratories.  The hypothesis formulated to investigate this event was that continued pilling testing in the ICI pill box changes the frictional properties of the cork liners, resulting in the difference pilling ratings.  The aim of this study was to decrease the inconsistencies in the pilling results by replacing the conventional cork lined pill box with a Perspex^TM pill box.  The smae or similar pilling results found for several of the knit facots tested in the two difference pill boxes, while for others there were some significant differences found.  In addition, while using the Perspex^TM pill box observations of the movement of the pilling tubes during testing provided evidence of greater fabric-to-fabric abrasion, rather the expected high degree of fabric-to-cork abrasion (or fabric-to-Perspex^TM) during pilling testing.

Nurses´ attitudes to single checking medications : before and after its use

We report nurses' attitudes towards the single checking of medications before and after the implementation of this procedure in an acute health-care setting. Data from a pre-implementation survey confirmed that some nurses held strong views against single checking. Following this survey, the hospital's medication administration policy was revised, a single checking resource manual was developed, 1–2 h nurse education sessions were held, the competencies of nurses to single check and to administer medications were assessed, and single checking was successfully piloted before hospital-wide implementation. Data from a survey conducted 18 months after the implementation indicated that nurses welcomed the single checking medication procedure, felt more confident using single checking and perceived that it made them more accountable for administering medications. The findings provide evidence that nurses' attitudes to single checking change remarkably in favour of its use with education and experience using this procedure.

Effect of fibre, yarn and knitted fabric attributes associated with wool comfort properties

In this replicated experiment, we investigated the comfort properties of single jersey fabrics composed of cashmere in blends with superfine wools of different fibre curvature (crimp) where the fibre diameter of the wool and cashmere were tightly controlled. The 81 fabrics were evaluated using the Wool ComfortMeter (WCM) which has been calibrated using wearer trials of wool knitwear. General linear modelling determined the best prediction models for log10 transformed fabric WCM values using 27 fibre, 16 yarn and 30 fabric attributes. Tighter fabrics were less comfortable. Progressively blending cashmere with wool progressively increased comfort assessment. The WCM was able to detect differences between fabrics which were more supple and springy, thinner and lighter, and were composed of more elastic, uniform and stronger yarns. Together these attributes explained 82% of the variance in WCM value.

Relationships between wearer assessment and the instrumental measurement of the handle and prickle of knitted wool fabrics

The relationships between wearer-assessed comfort and objectively measured comfort and handle parameters were investigated using 19 pure wool single jersey garments made of single ply yarns. Wearer trials were used to determine prickle discomfort, and whether wearers “liked” the garments. Fabrics then were objectively evaluated using the Wool HandleMeter, which measures seven primary handle attributes; and the Wool ComfortMeter (WCM), to predict a wearer's perception of fabric-evoked prickle. Wearer responses and the relationships within and between objective measurements and the effect of fibre, yarn and fabrics attributes were analysed by general linear modelling. Mean fibre diameter, fibre diameter coefficient of variation, yarn count, fabric thickness, fabric density, fabric mass per unit area and decatising affected one or more handle parameters. The best model for predicting wearer prickle discomfort accounted for 90.9% of the variance and included only terms for the WCM and WCM2. The WCM was a good predictor whereas mean fibre diameter was a poor predictor of whether wearers “liked” garments. Wearer assessment of prickle and whether or not wearers “liked” fabrics were independent of fabric handle assessment. The results indicate that the handle and comfort properties of lightweight, wool jersey fabrics can be quantified accurately using the Wool HandleMeter and the Wool ComfortMeter. For fabric handle, fibre and yarn characteristics were less important than changes in the properties of the fabric.

Effects of variation in wool fiber curvature and yarn hairiness on sensorial assessment of knitted fabrics

Previous investigations have shown that prickle discomfort sensations of wool fabrics are primarily determined by the mean fiber diameter of the wool. It is also known that differences in wool fiber curvature (crimp) affect softness of handle of greasy wool and of wool textiles. In a replicated experiment, we investigated if wearers could detect the effect of using 17 µm superfine wool of low (74°/mm) or high (114°/mm) fiber curvature, and when the wools were blended with 17 µm cashmere (fiber curvature 49°/mm) in differing proportions, on four comfort sensations. Eight single jersey knitted fabrics were assessed under a controlled protocol using forearm sleeves made of the test fabric and a control fabric. Data (37 sensorial assessments of high curvature wool fabrics; 38 sensorial assessments of low curvature wool fabrics) were analyzed using linear mixed model analysis (restricted maximum likelihood), which included fixed effects for wool type and blend ratio and a random effect for participant. The use of a control sleeve fabric reduced variance due to participant effects by providing an anchor for each sensation over time. Wool fiber curvature affected participant assessment of breathability, comfort, feel after exercise (damp/dry) and skin feel (prickly/soft), with preferred values associated with high curvature (crimp) superfine wool. Increasing the proportion of cashmere in fabrics increased skin feel (better assessed softness). Skin feel was strongly associated with the evaluation of the fabrics by the Wool ComfortMeter and with increasing hairiness of yarns.

Ultrafine wools: comfort and handle properties for next-to-skin knitwear and manufacturing performance

This study aimed to quantify the skin comfort and handle properties of a range of wool fabrics produced from ultrafine wool (13.7–15.1 µm) and in doing so determine if differences in fiber diameter and staple crimp frequency (5.3–7.1 crimps/cm) were important in these properties. The fabrics were evaluated using a range of subjective and objective measurement techniques, including the Wool ComfortMeter, the Wool HandleMeter and in wearer trials. This work indicated that single jersey fabrics made from ultrafine wool are approaching the limit of objective and subjective evaluation of next-to-skin comfort. The results from the Wool ComfortMeter, Wool HandleMeter and the wearer trial show that there were no significant effects that can be attributed to wool staple crimp (fiber curvature) in these ultrafine wool fabrics. The work also demonstrated a difference in the manufacturing response when knitted fabric made from wools of different fiber diameter (13.7–23.7 µm), and using yarns of the same count, resulted in a progressively higher fabric mass per unit area as mean fiber diameter was progressively reduced.

Fabric handle properties of superfine wool fabrics with different fibre curvature, cashmere content and knitting tightness

The handle properties of single jersey fabrics composed of superfine wools (17 μm) of different fibre curvature (114 vs. 74 °/mm) in blends with cashmere (fibre curvature 49 °/mm) were investigated. There were four blend ratios of cashmere (0, 25, 50, 75%) plus 100% cashmere. Each of the nine fibre blend combinations were replicated three times, and each was knitted into three tightness factors. The 81 fabrics were evaluated using the Wool HandleMeter, which measures seven primary handle attributes and Overall handle, and have been calibrated using a panel of experts and a wide variety of commercial fabrics. Results were analysed by ANOVA and general linear modelling. Tightness factor significantly affected all Wool HandleMeter attribute values, with the effect of tightness factor varying according to handle attribute. The Wool HandleMeter was able to detect differences between fabrics composed of superfine wool differing in fibre curvature, with lower fibre curvature wool fabrics having more preferred Overall handle and softer, looser, cooler, lighter and less dry handle attributes at some or all tightness factors compared with fabrics composed of higher fibre curvature superfine wool. Progressively blending cashmere with wool significantly improved Overall handle, increased soft and smooth handle, reduced dry, heavy and tight handle. Linear regression modelling indicated that fabric mass per unit area explained more than 50% of the variance in overall fabric handle and in combination with variations in fabric thickness and yarn elongation could explain 71% of the variance in Overall handle.

Effect of single and double austenitization treatments on the microstructure and hardness of AISI D2 tool steel

This investigation is concerned with the study of effect of Double Austenitization (DA) and Single Austenitization (SA) heat treatment processes on microstructure and mechanical property of AISI D2type cold worked tool steel. To maximize hardness, tool steels are used in a quenched and tempered condition. This involves heating the material to the austenitizing temperature (~850-1100. °C), quenching at an appropriate rate to form martensite, and tempering to reduce the retained austenite content and induce toughness. The merits of DA treatment isto promote dissolution of carbides at the same time proscribe grain coarsening significantly was attempted in D2 tool steel. The study has found that DA treatment has induced high hardness with insignificant growth in grains. The increase in hardness is attributed to increase in carbon content in matrix due to dissolution of carbides; whereas finer grains due to role of inclusions.