The influence of mechanical action on felting shrinkage of wool fabric in the tumble dryer

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Felting shrinkage of untreated wool fabric occurs easily during tumble drying. Mechanical action applied on fabrics plays a significant part in felting shrinkage of wool fabric. In general, the more severe the mechanical action of a washing or drying machine, the more rapid is felting shrinkage. However, both the degree of mechanical action applied on fabric and the type of mechanical action could influence felting shrinkage of untreated wool fabric. In the current study, fabric movement and felting shrinkage of untreated wool fabric at different rotation speeds of the drum in a tumble dryer under no heating condition were studied. Based on the different fabric movements at different rotation speeds of the tumble drum, the extent of impact force and rubbing force at different rotation speeds were assessed through their ranking. The total mechanical action applied on the fabric was expressed by the percentage of thread removal of “thread removal fabric” during drying process. The results showed that lowest mechanical force on fabrics could be achieved when the higher rotation speed of the drum was used for drying wool fabrics in tumble dryers, and it could prevent wool felting shrinkage. It was also found that falling of the fabric followed by impact to the drum wall caused less felting shrinkage than sliding with rubbing between fabrics. Therefore, falling movement of fabric could be a potential method to dry wool fabric in drying machines without causing severe felting shrinkage

Dimensional change of wool fabrics in the process of a tumble-drying cycle

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Currently domestic tumble dryers are popularly used for drying garments; however, excessive drying and the inappropriate way of tumble agitation could waste energy and cause damage to or the dimensional change of garments. Shrinkage of wool fabrics during tumble drying causes a serious problem for wool garments. The current study investigated the shrinkage of untreated and Chlorine-Hercosett–finished wool fabrics at different drying times. Temperature of air in the tumble dryer, temperature of fabric, moisture content of fabric, and dimensional change at different drying times were measured. For the duration of the tumble drying, the rise of fabric temperature and the reduction of moisture content on the wool fabric were investigated to explore their relationship to the shrinkage of wool fabrics in the tumble-drying cycle. It was found that the tumble-drying process can be divided into different stages according to the temperature change trend of wool fabrics. The shrinkage mechanisms of the untreated and the treated fabrics were different. The dimensional change of untreated wool fabric was caused mainly by felting shrinkage during tumble drying. Chlorine-Hercosett–finished wool fabric can withstand the tumble-drying process without noticeable felting shrinkage due to the surface modification and resin coating of surface scales of wool fibers. The finding from the current research provides further understanding of the shrinkage behavior of wool fabrics during the tumble-drying process, leading to optimizing operational parameters at specific stages of a tumble-drying cycle

Research progress on water-soluble chitosan

Chitosan has good film-forming property, adsorption, biocompatibility, biodegradability and antimicrobial properties, but it can only be dissolved in weak acidic aqueous solution and cannot be directly dissolved in water, which greatly limits its application. In order to increase its solubility in water, chitosan is modified, the research on the water-soluble derivatives of chitosan is reviewed in this paper, and its application in the protection of paper relics is briefly introduced. Chitin is a kind of natural polysaccharide macromolecular polymer synthesized by biology in animals and plants, which mainly comes from shrimp shelsl, crab shells, insect shells and so on. Chitosan (CS) is obtained by deacetylation of chitin. The chitin is deacetylated under homogeneous conditions, and water-soluble product can be obtained by controlling the degree of deacetylation at about 50% [1]. The primary hydroxyl group, secondary hydroxyl group and amino group on the glucosamine unit in the chitosan molecular chain, with strong reactivity, which can be modified and embellished by functionalization to improve its solubility

The influence of moisture content on shrinkage of wool fabrics during domestic tumble drying process

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Shrinkage of wool fabrics caused during tumble drying is a serious defect. In the drying process, the felting shrinkage of wool fabrics was influenced by the moisture content and temperature of wool fabric as well as mechanical action being applied on the wool fabric. In the current study, the relationship between moisture content of wool fabrics and shrinkage was studied in the drying programs under no heating condition or heated condition. This study also analyzed shrinkage behaviors of the untreated wool fabric and the Chlorine-Hercosett treated wool fabric with different moisture contents. For the untreated wool fabric, moisture content in the fabric could influence the mechanical properties of wool fibers, resulting in the different extent of felting shrinkage of wool fabric during tumble drying. For the Chlorine-Hercosett treated wool fabric at different initial moisture contents, there was no obvious variation in the length change under no heating condition, but a slight difference in the shrinkage under heated condition. The study could lead to the new guidance for efficient drying of wool fabric with less felting shrinkage

Investigation of fabric movement in a tumble dryer for the development of drying method for wool fabrics to save energy

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Tumble dryers are widely used for drying garments, but felting shrinkage could be caused to wool garments during tumble drying process. In order to dry wool fabrics or garments in tumble dryers, flat dry function has been introduced in the dryers, however the energy efficiency is very low. The current study investigated the fabric movement at different rotation speeds in the tumble dryer and their resultant performances in terms of specific moisture extraction rate (SMER), evenness of drying, fabric shrinkage, and fabric smoothness. For shrink-resist treated wool fabrics, tumble drying at the rotation speed to keep fabric movement in projectile motion accompanied with tumbling occasionally could achieve better energy efficiency, drying uniformity and fabric smoothness. For untreated wool fabrics, introducing vertical movement to the flat dry in the tumble dryer can improve the heat exchange between the fabric and hot air, resulting in the increase of energy-efficiency by approximate 30% than flat drying motionlessly. Wool fabric shrinkage can be controlled to be less than 2% with the smooth appearance of fabric at grade 3.5 after drying under the recommended drying condition. This study could help tumble dryer manufacturers design optimal drying methods for wool fabrics with the potential for the reduction of energy consumption

A SUPERVISED SINGULAR VALUE DECOMPOSITION FOR INDEPENDENT COMPONENT ANALYSIS OF fMRI

Functional Magnetic Resonance Imaging (fMRI) is a non-invasive tech-nique for studying the brain activity. The data acquisition process results a tempo-ral sequence of 3D brain images. Due to the high sensitivity of MR scanners, spikes are commonly observed in the data. Along with the temporal and spatial features of fMRI data, this artifact raises a challenging problem in the statistical analysis. In this paper, we introduce a supervised singular value decomposition technique as a data reduction step of independent component analysis (ICA), which is an effective tool for exploring spatio-temporal features in fMRI data. Two major advantages are discussed: first, the proposed method improves the robustness of ICA against spikes; second, the method uses the fMRI experimental designs to guide the fully data-driven ICA, yielding a more computationally efficient procedure and highly interpretable results. The advantages are demonstrated using spatio-temporal sim-ulation studies as well as a data analysis

Screening of functional antidotes of RNA aptamers against bovine thrombin

AbstractA specific RNA aptamer (T705) against bovine thrombin had been obtained after seven rounds of SELEX (systematic evolution of ligands by exponential enrichment) selection from a random RNA library previously. In order to further investigate the relationship between the structure and function of this aptamer, three truncated RNA aptamers, T705a, T705b and T705c, were designed according to the secondary structure of T705 RNA. Our results showed that T705c keeping the precise stem–loop structure but lacking most of the stem region sequence of T705 could inhibit clot formation in vitro in the same way as its parental form. We also report here that single-stranded DNA (ssDNA) antisense oligonucleotides, c′ and c′-22, which were complementary to different portions of T705c could act as efficient antidotes reversing the inhibitory activity of T705. It is demonstrated for the first time that ssDNA antisense oligonucleotides are potential antidotes of RNA aptamers and this may be an effective, rapid strategy to find antidotes of RNA aptamers which would be of important usefulness in basic research and drug screening

Room-temperature multiferroic hexagonal LuFeO3_3 films

The crystal and magnetic structures of single-crystalline hexagonal LuFeO$_3$ films have been studied using x-ray, electron and neutron diffraction methods. The polar structure of these films are found to persist up to 1050 K; and the switchability of the polar behavior is observed at room temperature, indicating ferroelectricity. An antiferromagnetic order was shown to occur below 440 K, followed by a spin reorientation resulting in a weak ferromagnetic order below 130 K. This observation of coexisting multiple ferroic orders demonstrates that hexagonal LuFeO$_3$ films are room-temperature multiferroics

Crystal Field Splitting and Optical Bandgap of Hexagonal LuFeO3 Films

Hexagonal LuFeO3 films have been studied using x-ray absorption and optical spectroscopy. The crystal splitting of Fe3+ is extracted as Ee′−Ee″ = 0.7 eV and Ea1′−Ee′ = 0.9 eV, and a 2.0 eV optical bandgap is determined assuming a direct gap. First-principles calculations confirm the experiments that the relative energies of crystal field splitting states do follow Ea1′\u3eEe′\u3eEe″ with slightly underestimated values and a bandgap of 1.35 eV