Table of Content - JFBI 6.3

Electrospun nanofibers have increasingly attracted attention to be used as new generation tissue engineering scaffolds since they have the nanofibrous structure, which can biomimic the native Extracellular Matrix (ECM). This paper gives the review of our 10 years research on electrospun nanofibers for tissue engineering. Natural polymers like collagen and chitosan have been electrospun into complex nanofibers to biomimic the native ECM both in structure and components. Collagen-chitosan or silk fibroin (SF) was also blended with synthetic poly (L-lactide-co-ε-caprolactone) (P(LLA-CL)) and electrospun into collgen-chitosan-P (LLA-CL) nanofibers or SF-P(LLA-CL) nanofibers to achieve both good mechanical properties and biocompatibility. Coaxial electrospinning was used to encapsulate the biomolecules into nanofibers to display antithrombotic properties. The nanofiber scaffolds have been used for skin, nerve and blood vessel tissue engineering in vivo.

In this paper, we investigated factors affecting movement restriction while wearing stab-resistant vests with the aim of improving their comfort. We measured the contact area and pressure between the vest and a dummy, and performed sensory tests for movement restriction in the wearer's arms and upper body using four vests of different sizes, weight and types of stab -proof material. The pressure distribution of the vests on a dummy was measured and cross-sections of dummy-worn vests were obtained by 3D scan. For these measurements, we controlled the tightness value, the ratio between vest waist circumference and dummy. In order to check the influence of vests on the movement of the arm and upper body, subjects evaluated movement restriction and the feeling of pressure on the waist, chest, abdomen and back. We discovered that vests tend to hang on the neck point, shoulder, chest and back. The pressure on the chest increased with increasing tightness value, while the abdomen was under pressured to a forward bending position. Thus, shorter stab-resistant materials at the vest front have less movement restriction. In the arms, subjects reported less movement restriction when they felt that the shoulder area was softer. Therefore, we discovered that contact area and pressure should be considered in the design of stab-resistant vests to improve the comfort of the wearer.

To investigate the compressive effects through microscopic features of flexible low-density open-cell PU foam during moulding process, FE simulation of deformation based on a regular dodecahedron cell unit with uniaxial compression behavior is undertaken to examine the mechanical properties of the vertical loading direction, and to facilitate the incorporation of solid PU material properties and variations in cell geometry. By the use of a factorial design, the mean strut thickness of solid struts has a positive non-linear effect on the maximum reaction force as compared against cell size with a negative non-linear effect. The Young's modulus of solid polymers had a positive linear effect on the response while the Poisson's ratio had the least impact on the response. Development of a simplified cell unit can model the behavior of open-cell PU foam under uniaxial compression which is an effective way to understand the mechanical behavior of foam during moulding process.

An abaya is a traditional Muslim woman's outer garment. It is black and worn on a day-to-day basis when women are outside their homes. The abaya absorbs most of the heat from sunlight in a hot climate as it is black, making the wearer very uncomfortable. In order to reduce absorption of heat in an abaya and to make the wearer more comfortable, it is proposed that a treatment with a solar energy reflector could enable the wearer to perspire less; thus allowing them to feel cooler. This paper investigates the thermal comfort properties of plain-woven fabrics dyed in black and treated chemically to reflect a proportion of sunlight's energy. The fabrics were made from 100% wool and two polyester/wool blends. The testing results showed that the fabrics that had received the reflective treatment possessed marginally improved thermal comfort properties as compared to fabrics without the treatment.

A new material poly-silk peptide was fabricated using the electropolymerization of Silk Peptide (SP) on the surface of a Carbon Paste Electrode (CPE) for the first time. The morphological feature of poly-silk peptide film was characterized by Scanning Electron Microscopy (SEM). The preparation conditions such as SP concentration, supporting electrolyte pH and scan cycles were optimized. A stable poly-silk peptide film could be obtained with scanning 16 cycles in pH7.4 Phosphate Buffer Solution (PBS) containing 0.6 g?¤L-1SP between -0.5 and +1.5V. In addition, a well-defined pair of oxidative and reductive peaks of poly-silk peptide was observed in 0.1M H2SO4solution (pH 1.1), resulting from the successive redox reaction of ?aOH, ?aC==O and ?aCOOH groups on poly-silk peptide.

In computer vision applications, human detection occupies an important position. HOG (Histograms of Oriented Gradient) is a classical algorithm which was used in the area of object detection. But the complex background would greatly affect the test accuracy when taking HOG as a human characteristic for human detection. In order to improve the accuracy of human detection, this paper applied a new algorithm which was based on foreground segmentation. We could get each closed region by Oriented Watershed Transform and Ultrametric Contour Map, then the foreground and the background could be distinguished. Finally we removed the background and calculated the foreground characteristic. The experimental results show that this approach was effective in improving detection accuracy.

Wool fabrics both in dry and wet state exhibit high thermal insulation and dry touch, but their main disadvantage - felting, caused by exposition of the fabrics to mechanical action under hot-wet state, might limit their generally excellent properties. Therefore, antifelting treatment is often used to avoid the fabric felting. However, when the level of antifelting treatment is exaggerated, thermal comfort properties of wet wool fabrics might get reduced. In the paper, the effect level of various antifelting treatments on thermal comfort properties of wet wool fabrics was studied with the objective, to determine the levels of treatment, allowing the reduction of the felting behaviour and simultaneously maintain the excellent thermal insulation and thermal contact properties of wool fabrics.

The study investigated the skin temperature (Tsk) at sixteen points, Stratum Corneum Water Content (SCWC) and Transepidermal Water Loss (TEWL) at fourteen points over the ventral and dorsal surfaces, during submaximal cycling exercise in an ambient temperature of 25℃, and a relative humidity of 60%. Nine healthy competitive males completed a 20 min rest on the cycle and 5-min warm-up, followed by a 30 min of cycle exercise at 70% maximal heart rate and 30 min recovery. Average mechanical power output and pedaling rate were 150 W and 70 rpm. The results showed that the ventral and dorsal skin temperatures were significantly decreased from a minimum of 0.68℃ up to 3.48℃ than those measured at rest before cycling. In accordance with the regions of declines in skin temperatures, the values of SCWC and TEWL almost attained 120 A.C.U. and 40~60 g/h.m2. Meanwhile, the subjects produced 0.45 L/h sweating throughout the experiment. The distribution state of Tsk, SCWC and TEWL could be visualized directly by a novel color mapping of human body. The results obtained suggest that during the submaximal cycling exercise, the reduction of skin surface temperature is associated with the evaporative heat loss due to skin sweat.

The aim of this study is to evaluate the effect of aerogel on Thermal Protective Performance (TPP) of fire fighter clothing. Specimens were treated by 5 wt% aerogel dispersed in acetone to obtain various add-on of aerogel and their TPP were evaluated by flame heat transmission test according to ISO 9151. The thermal degradation behavior, flame retardancy and water vapor permeability of aerogel treated specimens were also examined. Finally, the comparison of the burn injuries predicted by instrumented manikin testing of aerogel treated fire fighter clothing and existing fire fighter clothing were performed. The result showed that aerogel treated fire fighter clothing exhibited higher TPP than the existing firefighter clothing. This suggests that there application of aerogel in fire fighter clothing may be possible.

This paper proposes a new texture image segmentation algorithm using a Multi-resolution Markov Random Field (MRMRF) model with a variable weight in the wavelet domain. For segmentation on textile printing design, firstly it combines wavelet decomposition to multi-resolution analysis. Secondly the energy of the label field and the feature field are calculated on multi-scales based on variable weight MRMRF algorithm. Finally new segmentation results are obtained and saved. Compared with traditional algorithms, experimental results prove that the new method presents a better performance in achieving the edge sharpness and similarity of results.