Eco‐friendly plasma treatment of linen‐containing fabrics

In the present work, linen‐containing fabrics were treated with atmospheric pressure plasmas of oxygen, air and nitrogen, and the impact of plasma treatment conditions on the surface chemistry and topography was evaluated. Plasma treatment is accompanied by a remarkable improvement in the hydrophilic properties: creation of new functional groups along with a noticeable increase in the affinity of treated substrates for subsequent H₂O₂‐bleaching. The extent of improvement in wettability as well as subsequent bleachability is governed by both the plasma gas, i.e. oxygen > air > nitrogen > none, and the discharge power, i.e. the higher the power supply, the shorter and greater was the modification extent. Oxygen or air plasma treatment significantly upgrades the hydrophilicity, enhances the subsequent bleachability, saves time, water and energy as well as prevents or decreases pollution at the source, i.e. an eco‐friendly substitute for conventional scouring of linen‐based textiles.     

Discrete‐event simulation model of roll‐drafting process

This paper presents a model of the roll‐drafting process which is based on the concept of discrete‐event simulation (DES). This model is free of limitations and simplifications which are inherent in the known models of the roll‐drafting process and is able to trace each separated fiber within the roll‐drafting zone. Due to this feature DES model enables investigation of a wide range of roll‐drafting cases and representations. The influence of the parameters of the basic roll‐drafting model was studied. Models of the first and the second limit schemes, models with a randomly distributed velocity change point, and a model with a shifting velocity change point were elaborated and studied on the basis of the basic model of the roll‐drafting process. The effect of the feedback depth was simulated and analyzed in the frame of the model with the shifting velocity change point. The elaborated model and the obtained results will be useful for creating a neural network meta‐model of the roll‐drafting process.     

Tensile characteristics of Dref‐III friction core‐spun yarns

The tensile characteristics of Dref‐III friction spun yarns with jute as core and cotton as sheath components have been studied. Three yarns with different core–sheath proportions such as 55/45, 65/35 and 75/25 jute/cotton friction spun yarns were produced by using the Dref‐III friction spinning system. The influence of core and sheath components on the tensile properties at three different traverse rates at 150 mm/min, 750 mm/min and 1500 mm/min, respectively, have been reported. The work of rupture and specific work of rupture at break of these yarns were also analysed. From the test results, the maximum work of rupture was found in 55/45 core–sheath (jute/cotton) friction spun yarn when compared to 65/35 and 75/25 core–sheath (jute/cotton) friction spun yarns. It is due to the higher core–sheath interaction factor (CSI_T = 26.14) and better yarn‐packing density because of higher proportion of cotton fibres in the sheath component. The breaking tenacity and contribution factor of core and sheath component (CSI_T) of jute/cotton friction spun yarns were also analysed using multivariable ANOVA analysis.     

Hard‐to‐cook phenomenon in common beans — A review

Legumes are one of the world's most important sources of food supply, especially in developing countries, in terms of food energy as well as nutrients. Common beans are a good source of proteins, vitamins (thiamine, riboflavin, niacin, vitamin B₆) and certain minerals (Ca, Fe, Cu, Zn, P, K, and Mg). They are an excellent source of complex carbohydrates and polyunsaturated free fatty acids (linoleic, linolenic). However, common beans have several undesirable attributes, such as long cooking times, being enzyme inhibitors, phytates, flatus factors, and phenolic compounds, having a “beany” flavor, and being lectins and allergens, which should be removed or eliminated for effective utilization.

Grain quality of common beans is determined by factors such as acceptability by the consumer, soaking characteristics, cooking quality, and nutritive value. Acceptability characteristics include a wide variety of attributes, such as grain size, shape, color, appearance, stability under storage conditions, cooking properties, quality of the product obtained, and flavor.

Storage of common beans under adverse conditions of high temperature and high humidity renders them susceptible to a hardening phenomenon, also known as the hard‐to‐cook (HTC) defect. Beans with this defect are characterized by extended cooking times for cotyledon softening, are less acceptable to the consumer, and are of lower nutritive value. Mechanisms involved in the HTC defect have not been elucidated satisfactorily. Attempts to provide a definitive explanation of this phenomenon have not been successful. The most important hypotheses that have been proposed to explain the cause of bean hardening are (1) lipid oxidation and/or polymerization, (2) formation of insoluble pectates, (3) lignification of middle lamella, and (4) multiple mechanisms. Most researchers have reported that the defect develops in the cotyledons. Recently, some authors have suggested that the seed coat plays a significant role in the process of common bean hardening. A better knowledge of cotyledon and seed coat microstructure may lead to a better understanding of the causes of seed hardness.

In order to prevent the development of the HTC defect several procedures have been proposed: (1) appropriate storage, (2) controlled atmospheres, and (3) pretreatments. Probably, the most workable solution to the hardening phenomenon may be the development of materials less prone to HTC phenomenon.

Decreasing cooking time, increasing nutritive value, and improving sensory properties of seeds with HTC defect would have great nutritional and economical impact. Furthermore, an understanding of the mechanisms leading to reversibility of this phenomenon would provide insight into the development of the defect itself and would aid in the search for appropriate methods to prevent it.

Efforts to develop technological processes are needed in order to transform the HTC beans into edible and useful products. Several economic alternatives to utilize HTC common beans have been proposed: (1) dehulling, (2) extrusion, (3) solid state fermentation, (4) quick‐cooking beans, and (5) production of protein concentrates and isolates and starch fractions.     

A cross‐cluster and cross‐region analysis of fashion brand extensions

To obtain sustainable growth in revenue and market share, many fashion brands deploy category extensions and line extensions. In this paper, we examine how different fashion brands in Europe, North America, and Asia execute their brand extension strategies over different periods. By classifying different fashion brands into four clusters according to different price points and fashion contents, we conduct a cross‐region and cross‐cluster analysis to examine how different fashion brands execute their brand extension strategies. Our analysis is based on publicly available data associated with 48 fashion brands over a 90‐year period. We discuss our findings along with managerial insights.     

Neural network meta‐model of fibrous materials based on discrete‐event simulation. Part 1: discrete‐event simulation model of one‐dimensional fibrous material

We present a new approach to the simulation of one‐dimensional fibrous material irregularity. This approach is based on the idea of a random simulation step and the ability to trace each separate fiber or group of fibers during computer simulation. The simulation models developed are free of restrictions inherent in theoretical models and can simulate irregularity in a wide range of statistical distributions and simulation conditions. This paper presents the basic model of fibrous materials made from homogeneous separated fibers and its extension to blended fibrous materials, a model of thickness irregularity, and the extension of the basic model to a random group of fibers. The effects of the fiber length and fiber front ends were also simulated and analyzed.     

Novel sericin‐fixing agent containing rare‐earth ion for weighting silk fiber

Silk fibers were weighted with different weight gain rate by using a novel sericin‐fixing agent containing rare‐earth ion. Laser Raman spectra, scanning electron microscope (SEM), and amino acid analysis were studied to characterize the structures of weighted fibers. Laser Raman spectra verified that the content of the highly oriented β‐sheet conformation decreased in the weighted fibers. Amino acid analyses showed that the content of polar amino acid increased with the increase in weight gain rate. SEM analyses showed that the sericin was successfully fixed on the surface of the fibroin. Moreover, the mechanical and dyeing properties of the weighted fibers were also investigated. The results indicate that there was no significant difference in breaking strength and elongation between the weighted fibers and the control; the equilibrium moisture content and the color strength value (K/S) of the weighted fibers increased with increasing weight gain rate.     

Neural network meta‐model of fibrous materials based on discrete‐event simulation. Part 2: neural network meta‐model

Part 2 of the paper presents the neural network as a meta‐model for one‐dimensional fibrous materials which was elaborated on the basis of a discrete‐event simulation model that was presented in Part 1 of the paper. The architecture of the full‐size and part‐size network was developed and tested. The training set for the neural networks was obtained from the simulation model. The results of the sensitivity analysis of the neural networks have showed that the standard deviations of the fiber length and the fineness have no affect on the irregularity of the fibrous material. Testing has shown a high‐level coincidence between the simulation results and the prediction of the neural network meta‐model.     

Finite element simulation of three‐dimensional angle‐interlock woven fabric undergoing ballistic impact

This paper presents finite element simulations of three‐dimensional (3D) angle‐interlock woven fabric (3DAWF) undergoing ballistic impact. A micro‐structure model of the 3DAWF was established at the fiber tow level. Incorporated with commercial finite element code, ABAQUS/Explicit, the ballistic impact damage of the 3DAWF was simulated and compared with that in the experiment. Residual velocities of the conically cylindrical steel projectile (Type 56 in Chinese Military Standard) with different strike velocities were calculated and verified with those in the experiment. There are good agreements of the impact damage of the 3DAWF and the residual velocities of the projectile between finite element results and experimental results. The acceleration fluctuation record of the projectile and the stress wave propagation in the 3DAWF obtained from the simulation reveal the impact damage mechanisms of the 3DAWF. The strain rate effect of the fiber tows on the ballistic performance are also discussed. Such a micro‐structure model could be extended to the design of the impact behavior of the 3DAWF composites.     

Fabrication of poly(vinylidenefluoride‐co‐hexafluoropropylene) nanofiber yarns by conjugate electrospinning

Conventional electrospinning is an efficient method to fabricate polymer nanofibers which are usually collected as non‐woven mats. Recently, in order to fabricate a nanofiber yarn, conjugate electrospinning has been developed using coupled spinnerets applied with two high electrical voltages of opposite polarities In this paper, poly(vinylidenefluoride‐co‐hexafluoropropylene) (PVDF‐HFP) nanofiber yarns are prepared by conjugate electrospinning. The effects of the concentration and delivery rate of polymer solution and the distance between coupled spinnerets on the structure of PVDF‐HFP nanofiber yarns are investigated. The structure of the nanofiber yarns is observed by scanning electron microscopy (SEM). The mechanical properties of the nanofiber yarns are measured by electronic fiber strength tester. The results show that the PVDF‐HFP nanofiber yarn consists of a large number of nanofibers aligned well along the longitudinal axis of the yarn, and the nanofibers have diameters ranging from several hundred nanometers to a few microns. The diameter of nanofibers in yarns increases with the increase in the polymer concentration, which significantly affects the structure of nanofiber yarns. The PVDF‐HFP nanofiber yarn electrospun from the polymer solution with a concentration of 45% has the highest tensile strength of 0.25 cN/dtex and an elongation of 180.13%.     

A new approach to de‐curling force of single jersey weft‐knitted fabric

In this work, the curling behavior of cotton single jersey weft‐knitted fabric was studied using a new non‐destructive test method. Eighteen series of dry‐relaxed weft‐knitted fabric samples were produced with three different yarn twist levels (724.5 tpm, 807 tpm, and 890 tpm), two yarn twist directions (Z and S), and three different loop lengths (2.7 mm, 2.85 mm, and 3.2 mm). Curling behavior was characterized in terms of curling distance (CD), de‐curling force, and de‐curling energy. The results show that weft‐knitted fabric samples with a lower loop length and higher yarn twist level exhibited higher de‐curling force and de‐curling energy. It is indicated that the de‐curling force of weft‐knitted fabric samples produced from the Z‐twist cotton ring‐spun yarn is higher than that of the samples produced from the S‐twist cotton ring‐spun yarn. The regression analysis results also illustrate that de‐curling force and de‐curling energy are non‐linearly correlated with edge CD, and variation trends follow polynomial equations. The result of this research suggests that the curling behavior of weft‐knitted fabric can be predicted in terms of de‐curling properties.     

Effect of heating–cooling cycle on the opto‐structural properties of low‐density polyethylene fibres using two‐beam interference microscopy

A hot stage attached with a two‐beam interference (Pluta) microscope was used to apply a heating–cooling cycle (HCC) on low‐density polyethylene fibres (LDPE). The variation of the refractive indices (n ^∥ and n ^⊥) with the temperature was carried out during the heating and cooling of the LDPE fibres. The activation energy (E _a) and thermooptic coefficient (dn/dT) were calculated for the investigated LDPE fibres. The spectral dispersion curves, percent crystallinity and orientation function were determined for the treated LDPE fibres. It was found that the HCC for LDPE fibre implies: a reversible behaviour of both optical and structural properties against temperature and an improvement in the fibre crystallinity.     

Ageing effect of plasma‐treated wool

Atmospheric pressure plasma treatment of wool fabric, with a relatively short exposure time, effectively removed the covalently bonded lipid layer from the wool surface. The plasma‐treated fabric showed increased wettability and the fibres showed greater roughness. X‐ray photoelectron spectroscopy (XPS) analysis showed a much more hydrophilic surface with significant increases in oxygen and nitrogen concentrations and a decrease in carbon concentration. Adhesion, as measured by scanning probe microscopy (SPM) force volume analysis, also increased, consistent with the more hydrophilic surface leading to a greater meniscus force on the SPM probe. The ageing of fibres from the plasma‐treated fabric was assessed over a period of 28 days. While no physical changes were observed, the chemical nature of the surface changed significantly. XPS showed a decrease in the hydrophilic nature of the surface with time, consistent with the measured decrease in wettability. This change is proposed to be due to the reorientation of proteolipid chains. SPM adhesion studies also showed the surface to be changing with time. After ageing for 28 days, the plasma‐treated surface was relatively stable and still dramatically different from the untreated fibre, suggesting that the oxidation of the surface and modification or removal of the lipid layer were permanent.     

The effect of low‐temperature plasma for improving wool and chitosan‐treated wool fabric properties

In this study, plasma treatment was used to modify the surface properties of wool fabrics by partial removal of the scales and the lipid layer. The effects of low‐pressure pseudo‐discharge in oxygen gas on the dyeing properties of untreated and pretreated wool fabrics are discussed. Three dyes were used, namely acid dye, 1:2 metal complex dye and reactive dye. Different exposure times (1–5 min) of oxygenated plasma treatment were effected to improve the hydrophilicity, wettabillity, dyeability and the washing and light fastness properties of the dyed wool fabrics (which were increased by increasing the plasma exposure time). Also, the washing and light fastness properties of the chitosan‐treated wool fabrics were investigated. In addition, the presence of chitosan before or after the plasma exposure had no effect on the washing and light fastness properties of the wool fabrics.     

Food irradiation‐chemistry and applications∗

Abstract

Food irradiation is one of the most extensively and thoroughly studied methods of food preservation. Despite voluminous data on safety and wholesomeness of irradiated foods, food irradiation is still a “process in waiting.” Although some countries are allowing the use of irradiation technology on certain foods, its full potential is not recognized. Only 37 countries worldwide permit the use of this technology. If used to its full potential, food irradiation can save millions of human lives being lost annually due to food‐borne diseases or starvation and can add billions of dollars to the world economy. This paper briefly reviews the history and chemistry of food irradiation along with its main applications, impediments to its adoption, and its role in improving food availability and health situation, particularly in developing countries of the world.     

Flow behavior and functional properties of barley and oat water‐soluble β‐D‐glucan rich extractions

Flow characteristics and functional properties of water‐soluble β‐glucan rich extractions prepared from hulled barley, hulless barley and oats were investigated. Rheological behavior was studied using a coaxial viscometer over shear rates of 3.0‐ 1312s^?1. The shear rate‐shear stress data followed the power law and Herschel‐Bulkley models. The flow behaviour index values varied from 0.31‐0.97, indicating mildly to highly pseudoplastic nature of the aqueous solutions of β‐glucan rich extractions. The pseudoplasticity for the aqueous solutions increased with increasing concentration of extractions. The hulless barley β‐glucan rich extractions showed higher pseudoplasticity, consistency index, and yield stress values; absorbed less water and exhibited higher fat absorption and oil emulsifying properties than those of the hulled barley and oats. There was no discernible influence of fat contents on functional properties of the concentrates. Dough development time, arrival time, stability and softening of the dough were negligibly affected with addition of various β‐glucan rich extractions to the flours. Supplementation of β‐glucan rich extractions desirably increased the baking absorption of the flours. Bread with improved loaf quality could be obtained using various β‐glucan rich extractions upto a level of 1.00% (w/w), especially, from those of hulless barley cv. PNB 5.     

A simple,effective and inhibitor‐free thermal treatment for enhancing mold‐proof property of bamboo scrimber

European Journal of Wood and Wood Products - The bamboo scrimber has been widely used in building materials and interior decoration. However, the bamboo scrimber is very vulnerable to mold due to...     

Estimating mechanical properties of clear wood from ten‐year‐old Melia azedarach trees using the stress wave method

The objective of this study was to examine the potential of stress wave velocity (SWV) as a rapid and non-destructive method to estimate the mechanical properties of Melia azedarach wood. The SWV, dynamic modulus of elasticity (MOE_d), modulus of elasticity (MOE), modulus of rupture (MOR, bending strength) and density were determined on ninety 20 ? 20 ? 320 mm clear wood specimens, obtained from stems of three ten-year-old M. azedarach trees, and tested at environmental equilibrium in 20°C, 60?% relative humidity (a moisture content of approximately 12?%). There was a statistically significant (0.1?% level) but weak correlation (R²?=?0.23) between the SWV and MOE, but no statistically significant correlation was found between the SWV and MOR. Much better results for prediction of static properties of M. azedarach wood were obtained when SWV and wood density (WD) were used together through calculation of MOE_d in the air-dry condition (MOE: R²?=?0.76, MOR: R²?=?0.47), although in the case of MOR a model based on WD alone is slightly better (R²?=?0.58), and WD is also almost as good as MOE_d for predicting MOE. It is concluded that SWV coupled with WD can be employed as a predicting parameter to evaluate the mechanical properties of M. azedarach wood during the manufacturing process, although WD alone is also effective. The SWV alone would not be useful due to MOE being almost directly proportional to WD at this moisture content.

     

Three‐dimensional analysis of segmented pie bicomponent nonwovens

Three‐dimensional structural analysis utilizing digital volumetric imaging is used to fully understand the splitting of bicomponent fibers by hydroentangling. It was found that lower fabric density measured by solid volume fraction, higher degree of splitting and a higher thickness fiber orientation direction was evident at the jet streak valley position. Splitting was found to be more dominant on the surface of the fabrics. Washing the fabric increased fiber splitting and also resulted in more uniform splitting, but did not result in any significant change in local fiber orientation, that is, the structure.     

Effect of polymer‐binding on the specificity of lipases

Abstract

The flavour of a food system is strongly related to the production of free fatty acids (FFA). The controlled lipolysis and liberation of desired fatty acids are therefore of special interest in the food industry. Lipases that meet the food safety regulations, often do not necessarily possess the desired specificity. It was observed that the profile of FFA can be altered by a pre‐treatment of the lipase with synthetic, as well as natural, polymers. The profile of fatty acids released during incubation in milk was strongly correlated to the polarity of polymer used. The higher the polarity of the polymer, the more unsaturated fatty acids were liberated. After an incubation of the untreated lipase in milk, the oleic‐ versus stearic acid was found to be 3:1. However, using a lipase modified with a dimethyl polysiloxane (Mc Reynolds constant is 44), the ratio was found to be 1.5:1 and a modification with cyanoallyl polysiloxane (Mc Reynolds constant: 844) increased the ratio to 5:1. When applied for lipolysis in food systems, a modification with pectin A was found to be most effective. In this case no covalent bonds between the polymer and the lipase were formed, and therefore, its safety status does not change.