Effect of enzymatic treatment and reactive dyeing on the low stress mechanical properties of linen fabric

The present study was concerned mainly with the assessment of the modification of low stress mechanical properties of linen fabric that were induced by enzymatic treatment. In addition, the effect of dyeing with reactive dye on the enzyme treated linen fabric on the low stress mechanical properties were also investigated. Kawabata Evaluation System for Fabric (KES-F) instrument was used for assessing the low stress mechanical properties, i.e. tensile, shearing, bending, compression, and surface properties. Experimental results showed that the enzymatic treatment could alter those properties to different extent depending much on the concentration of enzyme used.     

A comprehensive study of silicone-based cosmetic textile agent

In recent years, textile materials have also found applications in the cosmetic field as more and more commercial cosmetic textile agents are now available in the market. In this paper, one commercially available cosmetic textile agent (CTA) for skin caring benefits was used for making the cosmetic textiles. Systematic characterization methods were established to assess their performance in terms of material identification, fabric performance properties as well as biological safety and biological response to human skin. The experimental results showed that after the treatment of cosmetic textile agent, the fiber surface was covered with a thin layer of smooth material, thereby contributing several alterations to fabric properties and providing a better hand feel to human body. The durability of cosmetic textile was considerably satisfactory with respect to the abrasion resistance and washing cycles. The experimental results also illustrated that the cosmetic textiles might probably enhance the replacement of cells with the newly regenerated ones in the skin structure of human body, and thus provided a more efficient turning-over and replacement of skin components.     

A comparative study of wool fibre surface modified by physical and chemical methods

The wool scale present on the fibre surface gives rise to certain unwanted effects such as felting and poor wettability in textile wet processing. In general practice, the removal of scale was done either by surface modification through physical/chemical degradation of scale or by deposition of a polymer on the scale. In modern treatment, combination of both methods is usually carried out. Since the deposition of a polymer on the fibre surface depends much on the surface characteristic of the fibre, therefore, the surface property of modified fibre is an important factor for polymer application. On the other hand, the surface modification methods may also result in improved hydrophilicity of fibre. The present paper investigated the surface physico-chemical properties of wool fibre under the influence of different surface modification treatments: (i) low temperature plasma (LTP) treatment with nitrogen gas and (ii) chlorination. The surface physico-chemical properties of the LTP-treated and chlorinated wool fibres were studied which included contact angle measurement with different solvents, determination of critical surface tension and surface free energy. Experimental results showed that these selected properties were altered after the surface modification treatments. In addition, a polymer was deposited in the treated wool fabrics and scanning electron microscope was used for assessing the surface morphology.     

Characterization and analysis of the active contents of nano-chemicals for textile application

In this paper, two nano-chemicals in the form of nano-suspensions were obtained commercially from the market. These two nano-chemicals were claimed to have UV-protective and anti-bacterial functions, but the active ingredients of these nano-chemicals were not disclosed. This was commonly found in commercial nano-chemicals used for textile application. Therefore, the aim of this paper was to use some simple analytical methods for evaluating the active ingredients of the nano-chemicals and hence provide an evaluation procedure for the industry. The particle sizes of the nano-suspensions were examined with a particle size analyzer. The results revealed that originally most of the particles of anti-bacterial nano-suspension fell into the range between 400 nm to 640 nm, but upon ultrasonic method for further dispersion, the particle size was confirmed to be smaller than 100 nm. In the case of UV-protective nano-suspension, its particle size was smaller than 100 nm. The active contents were characterized and analyzed using an inductively coupled plasma optical emission spectrophotometer and it was revealed that the major metals present in these nano-suspension were silver, titanium, and zinc with different concentrations. Also the major organic compositions of the nano-suspensions were identified by a GC/MS spectrometry. The results were qualitatively and quantitatively discussed.     

小麦与黑麦类远缘杂交中结实性问题的研究

远缘杂交是遗传和育种研究的一个重要内容,它首先遇到的问题是杂交不易成功,杂种后代不育,总称“结实性”问题。本文主要是介绍小麦与黑麦类远缘杂交中,当代结实率和杂种结实性两方面的研究结果,特别是不同亲本类型以及正、反交对结实性的显著影响。     

Modelling pathogen competition and displacement– <Emphasis Type="Italic">Phytophthora infestans</Emphasis> in Scandinavia

Populations of Phytophthora infestans have displaced less fit populations in a number of regions, but not in Scandinavia. In order to study this process, a simple epidemic model was developed, based on the Lotka-Volterra model for competition. The model contains two epidemics, each with logistic growth of two separate populations that interact with each other in that they compete for the same resource base (the plant). In Scandinavia, epidemics from suspected oospore infections are thought to start earlier than those originating from tubers, so routines were added to allow the epidemics to start at different time points. A numerical solution to the model was developed using the deSolve package of the open-source statistical program ‘R’. The resulting model allows examination of the relative importance of different values for the apparent infection rates and starting parameters for the two sub-epidemics. If epidemics from oospore infections start earlier than those from tuber infections, the delay for epidemic initiation via tuber infection would require extremely high values of r in order for this population to dominate at the end of the season. This could be one reason for the lack of persistent clones in the Scandinavian Phytophthora infestans population.     

Phytophthora infestans in a single field in southwest Sweden early in spring: symptoms, spatial distribution and genotypic variation

Sixty-eight isolates of Phytophthora infestans were collected from an early planted, fleece-protected potato field in southwest Sweden in May 2001. No infection was observed in the neighbouring fields. In the field investigated, infected plants were found in six discrete foci, with symptoms almost exclusively observed in the lower part of the canopy and numerous infections found on stems and on leaves touching the ground. The structure of the population was analysed based on mating type, mitochondrial haplotype and microsatellites (SSRs) as markers. Both mating types were present and haplotypes Ia and IIa were detected. Among 61 isolates analysed with microsatellite markers, 14 multilocus genotypes were distinguished based on six polymorphic loci. Out of the six foci, three included 3–5 genotypes each. There were unique genotypes in all foci, except two closely situated to each other. These findings strongly suggest that soilborne oosporic inoculum contributed significantly to initiate the late-blight epidemic in the investigated field.     

Virulence spectrum of Puccinia hordei in barley production systems in Ethiopia

Barley leaf rust caused by Puccinia hordei is an important disease of barley in Ethiopia. In the 2003 and 2004 cropping seasons, surveys of P. hordei were conducted on fields in the main rainy, residual moisture and short rainy season-barley production systems. A total of 381 isolates were analysed on 12 barley differential hosts carrying different Rph resistance genes ( Rph1 – Rph12 ). Based on infection phenotypes on leaf rust ( Rph ) resistance genes, seven pathotypes were identified, namely ETPh7611, ETPh7631, ETPh6611, ETPh7651, ETPh7671, ETPh7653 and ETPh7633, with frequencies of 63·0, 21·5, 6·8, 2·9, 2·6, 2·1 and 1·2%, respectively. ETPh7611 and ETPh7631 were the most common pathotypes found in all the surveyed areas of the three production systems. ETPh7653 was found in the small rainy season production system only. ETPh7671, ETPh7653 and ETPh7633 were the most virulent, but the least frequent, pathotypes. All isolates were virulent on resistance genes Rph1 , Rph4 , Rph8 , Rph9 , Rph11 and Rph12 . Virulence against Rph3 and Rph7 was absent. Genes Rph2 , Rph6+2 , Rph5 and Rph10 were effective against 96·3, 88·9, 65 and 2·4% of the rust isolates tested, respectively.