An introduction to a new direct testing method for characterizing pressure in compression fabrics

A newly developed direct pressure measuring system known as the CRIM Pressure System was compared with a traditional direct measuring device, the PicoPress Compression System, for compression bandage and hosiery samples. PicoPress measurements were taken both on the CRIM system and on research participants. Initial results indicated a good correlation between CRIM Pressure System and PicoPress participants’ measurements.     

The Influence of Air on the Properties of Heated Wool

A comparison is made of a direct method of measuring the compression provided by support hosiery, suitable for use in clinical studies, and an indirect method involving the measurement of hosiery tension, which may be suitable for use by hosiery manufacturers. There is shown to be a significant correlation between the results obtained with the two methods at the ankle and calf. There were some discrepancies between the results obtained when measurements were made at the thigh, and the possible reasons for these are discussed.     

Predictive modelling of compression garments for elastic fabric and the effects of pressure sensor thickness

This research has been conducted to develop mathematical models to predict the compression pressure and strain value of fabric based on Laplace’s law. The experiment was designed in accordance with the strain values of stretched fabric in order to make prediction of compression pressure. The fabrics covered on rigid cylindrical models and thigh part of human body were compared and measured for pressure values using compression tester. The results revealed that pressure values on rigid body were overestimated which may result from the cause of sensor thickness. Later, correction factor was included in calculations in order to get rid of the overestimated pressure. It was also found that predicted pressures were close to the ones being measured on rigid body by compression tester after multiplying with the correction factor, while soft tissue surface had no influential effect on pressure perturbation and pressure-measured values were close to the predicted pressure values obtained from modelling.     

基于三维扫描的医疗袜压力分布预测模型研究

基于三维人体扫描获取的人体表面点云数据和拉普拉斯方程,建立医疗袜与腿部接触的服装压分布理论预测模型。选择常用的Ⅰ级、Ⅱ级、Ⅲ级医疗压力袜以及3名在校大学生进行试穿,按照建立的理论模型计算压力袜和腿部接触的压力分布,并采用AMI3037型接触式气囊压力测量系统测试受试者穿着医疗袜时的实际接触压力,验证预测模型的实用性。结果表明,理论值和实测值基本一致,在一定程度上表明基于非接触式三维人体扫描的医疗袜压力分布预测方法可行。     

Thermal and pressure‐temperature denaturation kinetics of bacillus subtilis α‐amylase: A study based on gel electrophoresis

Abstract

The commercially available enzyme Bacillus subtilis α‐amylase was characterized by a molecular weight of about 55 kDa and contained isozymes with pI values ranging in a narrow zone (4.6–5.3). Furthermore, the sample was confirmed to contain no disulfide bonds. Upon thermal denaturation in the presence of sodium dodecyl sulfate, a band at half molecular weight was noticed, indicating that the native enzyme might be a dimeric form. Thermal as well as pressure‐temperature denaturation kinetics were investigated using gel electrophoresis and both could accurately be described by a first order kinetic model. For thermal denaturation an activation energy of 283 kJ/mole was calculated. As far as pressure‐temperature denaturation is concerned, activation energy and activation volume at a constant pressure of 5500 bar and a constant temperature of 40°C were calculated respectively as 77.6 kJ/mole and ‐23.2 cm³/mole. These values were compared with those for thermal and pressure‐temperature inactivation of Bacillus subtilis α‐amylase, as determined from residual enzyme activity measurements. No significant differences between the activation energy and volume characterizing denaturation and inactivation of Bacillus subtilis ct‐amylase were observed.     

RELATIONSHIP BETWEEN WATER ACTIVITY AND CRISPNESS OF EXTRUDED RICE CRISPS

Extruded rice crisps were adjusted to water activities in the range of 0.05–0.65, and texture measurements were carried out by single compression or compression of a layer of 10 specimens. Sensory crispness ranking was performed by a panel familiar with texture evaluation. Several parameters were derived from the force/displacement curves, and a crispness indicator was calculated on the basis of the relationship between the texture parameters and water activity. This crispness indicator showed best correspondence sensory results, especially when layer compression was performed.     

对我国袜子标准的几点建议

通过对我国各个不同时期袜子标准变化的分析,再与相关的针织品标准及国外的袜子标准进行比较,进而得出国内袜子标准的不足,并提出几点改进建议。     

EFFECT OF HIGH HYDROSTATIC PRESSURE ON SPORES OF GEOBACILLUS STEAROTHERMOPHILUS SUSPENDED IN SOYMILK

The inactivation of Geobacillus stearothermophilus spores (ATCC 7953) inoculated in soymilk was investigated using high hydrostatic pressure (550, 585 and 620 MPa) in combination with temperature (70, 80 and 90C) for selected times (2 s to 15 min). Inactivation of spores occurred at all selected treatments. Less than 10 CFU/mL of G. stearothermophilus were observed after 7 min of treatment at 620 MPa and 90C. An increase in the inactivation rate constant, at the highest pressure, was observed, resulting in a decrease in D values at all temperatures. D values were calculated as 10.6, 6.2 and 3.5 min for 70, 80 and 90C, respectively after pressurization at 620 MPa. z_p values decreased as temperature increased with values ranging from 142 to 238 MPa. The activation energy required for inactivation of G. stearothermophilus spores in soymilk, at the selected treatments, was in the range of 37.9–57.4 kJ/mol.     

Modeling the mechanical and compression properties of polyamide/elastane knitted fabrics used in compression sportswear

A compression sportswear fabric should have excellent stretch and recovery properties in order to improve the performance of the sportsman. The objective of this study was to investigate the effect of elastane linear density and loop length on the stretch, recovery, and compression properties of the weft-knitted polyamide/elastane (PA/EL) stretchable fabrics used in sportswear. Two different tests were performed to study the stretch and recovery properties of the fabric 1st: under low power force and 2nd: cyclic loading under high tension force. Kikuhime pressure sensor was used to measure the pressure generated by different PA/EL knitted sample garment sleeves. It was found that with the increase in elastane linear density there is an increase in fabric course density, areal density, recovery percentage, and compression, and fabric stretch percentage and elongation percentage decreased in both course and wale direction. The results of fabric samples were analyzed in Minitab statistical software. The coefficients of determinations (R² values) of the regression equations showed good prediction ability of the developed statistical models.     

带锥斗筒仓中稻谷的密度与应力分布模型

采用LHT-1粮食回弹模量仪测定稻谷堆的压缩密度,建立带锥斗筒仓中稻谷堆的密度、应力与粮层深度关系的微分方程组,用数值方法计算带锥斗筒仓中稻谷密度、应力与粮层深度关系,由积分法计算出筒仓中稻谷的储藏总质量。试验结果表明,淮稻5号(含水率为10.38%~18.30%w.b.)的密度随竖直应力(0.495~245.892 kPa)增大而增大(582.772~696.593 kg/m~3)。模型计算结果表明,在带锥斗筒仓的筒体部分,稻谷堆密度随着粮层深度的增加而增大;到锥斗部分,稻谷堆密度随着粮层深度的增加而逐渐减小。在带锥斗筒仓的筒体部分,稻谷堆的竖直应力随着粮层深度的增加而增大;在锥斗部分,稻谷堆的竖直应力则随着粮层深度的增加而减小。在带锥斗筒仓中的筒体部分,稻谷堆的侧向应力随着粮层深度的增大而增大;在筒体与锥斗结合处,稻谷堆的侧向应力突然增加;到了锥斗部分,稻谷堆的侧向应力随着粮层深度的增大先稍增大再逐渐减小。     

锦纶弹力丝袜加弹织造一步法生产工艺

介绍了加弹织造一步法生产锦纶弹力丝袜的新工艺 ,比较了该工艺与传统工艺的技术特点 ,并以规模为 50台袜机的小企业为例 ,对改造前后的经济效益进行了对比分析 ,结果显示改造后的经济效益可达到改造前的十倍。     

PHYSICOCHEMICAL PROPERTIES OF FRESHLY BAKED AND STORED WHOLE-WHEAT MUFFINS WITH AND WITHOUT FLAXSEED MEAL

Whole‐wheat muffins and batter were prepared with 0–5% flaxseed meal or by direct substitution of vegetable oil with flaxseed oil, and were evaluated for physicochemical properties. The storage properties of muffins were evaluated over 5 days at 0.44 relative vapor pressure (RVP) and ambient temperature. Batter viscosity increased from 2730 ± 530 to 12,775 ± 4425 cps with increasing flaxseed meal content while other properties were unaffected. When flaxseed meal was added at 5%, the maximum force for compression of freshly baked muffins increased from 369.6 ± 3.0 to 594.6 ± 10.2 g while the internal elasticity decreased from 60.2 ± 0.5 to 55.4 ± 1.6. Freshly baked muffins with flaxseed meal had lower color scores, L, and a values than control muffins. The storage stability of muffins was unaffected by the addition of flaxseed meal. Flaxseed meal or oil can be used in muffins to enhance the nutritional value without detrimentally changing the freshness or storage properties.     

SUCROSE AND ULTRA HIGH PRESSURE INACTIVATION OF SACCHAROMYCES CEREVISIAE AND LISTERIA INNOCUA

D‐values for ultra high pressure inactivation of Saccharomyces cerevisiae and Listeria innocua were evaluated in commercial applesauce with selected concentrations of soluble solids ranging from 13 to 60%. Applesauce with S. cerevisiae was compressed to 300 MPa and immediately decompressed (identified as 0 s) or held at 300 MPa for 30‐s intervals for 150 s at room temperature. Applesauce with L. innocua was treated at 375 MPa for 0 to 300 s at room temperature. D‐values for both microorganisms at soluble solids concentrations of 13, 20 and 30% were calculated. D‐values for inactivation of S. cerevisiae were 26.3, 29.9 and 46.5 s in applesauce adjusted with sucrose to 13, 20 and 30% soluble solids, respectively. D‐values for inactivation of L. innocua were 40.2, 55.2 and 120.6 s in applesauce also adjusted with sucrose to 13, 20 and 30% of soluble solids. Ultra high pressure treatment of commercial applesauce inoculated with S. cerevisiae or L. innocua adjusted to 40, 50 or 60% soluble solids reduced an initial inocula of 10⁷to 10⁶by less than 1 log. Soluble solids concentrations greater than 30% provide a baroprotective effect on inactivation by high pressure treatment. The use of ultra high pressure technology by the food industry to inactivate microorganisms may be limited in food models with high soluble solids concentrations. Soluble solids adjusted with sucrose concentrations greater than 30% protect against the destruction of microorganisms. An effective pressure treatment that ensures the microbial stability of foods depends on an understanding of the relationship between microorganisms and food components.     

Modeling the effect of elastane linear density,fabric thread density,and weave float on the stretch,recovery, and compression properties of bi-stretch woven fabrics for compression garments

The aim of this study was to investigate the effect of elastane linear density, thread density, and weave float on the stretch, recovery, and compression properties of bi-stretch woven fabrics for compression garments. Fabric samples were produced using elastane core-spun cotton yarns both in the warp and weft. The elastane linear density, fabric thread density, and weave float size were used as input variables while fabric contraction, subgarment pressure, fabric stretch, and recovery were taken as response variables. Two different elastane linear densities, i.e. 44 and 78 dtex, two different thread densities, and three different weave designs, i.e. 1/1 plain, 2/2 z-twill, and 3/3 z-twill were used. The results of fabric samples were analyzed in Minitab statistical software. The coefficients of determinations (R-sq values) of the regression equations showed good prediction ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of bi-stretch fabrics to attain specific stretch, recovery, and compression properties.     

TEXTURAL PARAMETERS IN COMPRESSION TESTING OF A GEL MADE FROM FRESH AND FROZEN FISH MINCE

The relation between deformability modulus and yield stress is evaluated in compression testing of a model product made from fresh and frozen stored mince of cod. The experiments were performed with a compression rate of 120 mm/min. Preliminary experiments showed decreasing values of yield stress when compression rates were below 50 mm/min. Two moduli were calculated from the slope of the compression curve; α₁, initially (small deformations) and α₂ in a linear part of the curve shortly before rupture of the gel. α₂ was linearly related to yield stress in gels of different water content, and in gels made from fresh and frozen raw material. α₁ showed different relations to yield stress depending on quality of the raw material.     

涤棉针织袜抗菌防臭整理

研究抗菌整理剂的浓度、浴比、浸渍温度和时间、焙烘温度和时间等工艺参数对涤棉针织袜抗菌防臭整理效果的影响，确定最佳工艺条件，并对针织袜的服用性能及耐久洗涤性能进行测试。结果表明，经最佳工艺整理的针织袜抗菌防臭效果良好，服用性能没有明显变化，具有良好的耐久洗涤性能。     

THE ANALYSIS OF STRESS RELAXATION DATA OF SOME VISCOELASTIC FOODS USING A TEXTURE ANALYZER*

Uniaxial compression test for dough and several commercial products like jello, mozzarella cheese, cheddar cheese, tofu and sausage (cooked and uncooked) was performed using a texture analyzer (TA). Percent stress relaxation (%SR ), k1 (initial rate of relaxation), k2 (extent of relaxation) and relaxation time (RT) were calculated and compared for different products. The TA software was used to convert the raw SR data into a linear form. Constants k1 and k2 were determined from the intercept and slope of the linear data. Higher values of %SR and k2 (90 and 9, respectively) indicated higher elasticity for jello, whereas wheat flour dough samples showed the lowest values (20–30) for %SR and 1 to 2 for k2. The RT and k1 values were not good indicators for differentiating different products based on their viscoelastic behavior. Measurement of RT was limited by the maximum time for which the data were collected, whereas k1, because of its mathematical form, needed careful interpretation. In this study, %SR was found to be a good measure to interpret viscoelasticity of different food samples.     

双路进线电脑袜机成圈机构的建模研究与运动仿真

针对国内现有双路进线电脑袜机结构设计方法较传统,缺乏机构动力学分析和仿真研究,存在运动平稳性不高的问题,在对双路进线电脑袜机成圈机制和关键工艺点研究的基础上,分析了织针和三角瞬时受力状况,采用Solid Works三维建模技术创建了双路进线袜机成圈机构的三维模型,进行了机构动力学研究。运用ANSYS有限元分析技术,对主要成圈机件进行了运动模拟仿真,得到了织针位移、速度、加速度曲线,并根据仿真结果对成圈机件进行了设计优化。结果表明,在成圈编织0.19 s(转速为300 r/min)时,加速度最大值为0.75×102m/s2,此值比优化设计前有明显减小,提高了双路进线电脑袜机的运动平稳性。     

Mechanical behaviour of hazelnuts used for table consumption under compression loading

Nuts of four hazelnut varieties and five new selections used for table consumption were compressed at the moisture content of 6% wet basis to measure shell resistance to breakage. Rupture force, rupture energy and nut specific deformation were measured under three compression loading positions. Physical parameters of nuts were also evaluated to relate them to the data obtained by compression test measurements. Rupture force and nut specific deformation are the most discriminant parameters that can be used to describe the behaviour under compression, while rupture energy values show fewer differences among the considered varieties. The values of force required to break nut shell ranged from 322.2 to 769.3 N. The lowest values of force were generally obtained along the y‐axis, the transverse axis containing the major dimension at right angles to the longitudinal axis. Nut specific deformation ranged from 3.35 to 11.76%. Correlations between physical and texture parameters showed that values of force, energy and deformation were dependent on different parameters that varied in the three considered axis. The most used varieties, Ennis and Barcelona, showed high mean values of force rupture to break shell and low deformability, while Tonda Giffoni and Tonda Bianca were easy to break. Among the new selections, L35 and B6, with mean values of force rupture less than 428 N and values of nut specific deformation higher than 8%, were suitable for table consumption. Copyright © 2006 Society of Chemical Industry