Novel feature of nano-titanium dioxide on textiles: antifelting and antibacterial wool

In this study, the antifelting and antibacterial features of wool samples treated with nanoparticles of titanium dioxide (TiO2) were evaluated. To examine the antifelting properties of the treated samples, the fabric shrinkage after washing was determined. The antimicrobial activity was assessed through the calculation of bacterial reduction against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. TiO 2 was stabilized on the wool fabric surface by means of carboxylic acids, including citric acid (CA) and butane tetracarboxylic acid (BTCA). Both oxidized samples with potassium permanganate and nonoxidized wool fabrics were used in this study. The relations between both the TiO2 and carboxylic acid concentrations in the impregnated bath and the antifelting and antibacterial properties are discussed. With increasing concentration in the impregnated bath, the amount of TiO2 nanoparticles on the surface of the wool increased; subsequently, lower shrinkage and higher antibacterial properties were obtained. The existence of TiO2 nanoparticles on the surface of the treated samples was proven with scanning electron microscopy images and energy-dispersive spectrometry.

Photo induced silver on nano titanium dioxide as an enhanced antimicrobial agent for wool

In this study an effective nanocomposite antimicrobial agent for wool fabric was introduced. The silver loaded nano TiO(2) as a nanocomposite was prepared through UV irradiation in an ultrasonic bath. The nanocomposite was stabilized on the wool fabric surface by using citric acid as a friendly cross-linking agent. The treated wool fabrics indicated an antimicrobial activity against both Staphylococcus aureus and Escherichia coli bacteria. Increasing the concentration of Ag/TiO(2) nanocomposite led to an improvement in antibacterial activities of the treated fabrics. Also increasing the amount of citric acid improved the adsorption of Ag/TiO(2) on the wool fabric surface leading to enhance antibacterial activity. The EDS spectrum, SEM images, and XRD patterns was studied to confirm the presence of existence of nanocomposite on the fabric surface. The role of both cross-linking agent and nanocomposite concentrations on the results was investigated using response surface methodology (RSM).

Self-cleaning and color reduction in wool fabric by nano titanium dioxide

Wool is a textile material that is valued for its strength, warmth, water resistance, and texture. But this natural fiber of the protein keratin lacks the stain resistance of synthetic fabrics and is also generally susceptible to harsh processing conditions. In this study, raw and oxidized wool fabrics were treated with nano titanium dioxide (TiO2) powder in an ultrasonic bath. These particles were linked to the wool surface by butane tetra carboxylic acid and also sodium hypophosphite was used as a catalyst. The photo-catalytic activity of TiO2 nanoparticles deposited on the wool fabrics was followed by the degradation of Acid Blue 113 as a stain and also determined by the degradation rate of food stains such as coffee, tea, and fruit juice under the ultraviolet rays. The results showed that increasing the amount of nano TiO2 leads to improved degradation of stains on the treated fabric.

The role of nano colloid of TiO2 and butane tetra carboxylic acid on the alkali solubility and hydrophilicity of proteinous fibers

One of the main problems of wool as an important proteinous fiber is low resistance against alkali media. Finding a way to solve this problem without any influences on other fiber characteristics is still a matter of research. Using nano particles on textile materials is a new approach to produce novel properties. Here, nano titanium dioxide (NTO) particles along with butane tetra carboxylic acid (BTCA) were sonicated in the ultra sound bath and applied as a nano colloid on the wool fabric. BTCA played different roles as wool cross-linker, a polyanionic agent, and stabilizer for nano TiO2. Various concentrations of NTO and BTCA were applied through impregnation of the fabric in ultrasonic bath followed by curing. The resistance of fabrics against alkali was assessed by solubility in sodium hydroxide and the hydrophilicity monitored by the water drop absorption time and the contact angle before and after UV irradiation. Interestingly, the alkali solubility of the nano TiO2 treated wool fabrics reduced while the fabric became more hydrophilic. This fact was shown by the testing results and is thoroughly discussed in the article. The response surface methodology (RSM) was also applied to find the optimum conditions for the wool fabric treatment.

Reducing photoyellowing of wool using nano TiO2

Wool is the most important animal fiber used in textile industries, but its photostability is very low. Scientists have searched for new ways to increase the photostability of wool. As TiO2 nano particles have features suitable for new applications, the UV-blocking power of nano TiO2 may be used for protecting fabrics against UV rays. Treatment of wool with TiO 2 can be effective for controlling photodegradation. This study focused on protecting wool fabric against UV rays using nano TiO2. To this end, oxidized and raw wool were treated with citric acid as the cross-linking agent and different concentrations of nano TiO2. The whiteness and yellowness of wool fabric samples were reported. XRD patterns proved the existence of TiO2 nano-particles on the wool surface. Finally, the results revealed that nano TiO2 is a suitable UV absorber on wool fabric and its effect depends on concentration.

Sunlight-induced coloration of silk

Silk fabrics were colored by gold nanoparticles (NPs) that were in situ synthesized through the induction of sunlight. Owing to the localized surface plasmon resonance (LSPR) of gold NPs, the treated silk fabrics presented vivid colors. The photo-induced synthesis of gold NPs was also realized on wet silk through adsorbing gold ions out of solution, which provides a water-saving coloration method for textiles. Besides, the patterning of silk was feasible using this simple sunlight-induced coloration approach. The key factors of coloration including gold ion concentration, pH value, and irradiation time were investigated. Moreover, it was demonstrated that either ultraviolet (UV) light or visible light could induce the generation of gold NPs on silk fabrics. The silk fabrics with gold NPs exhibited high light resistance including great UV-blocking property and excellent fastness to sunlight.

Decolorization and mineralization of an azo reactive dye using loaded nano-photocatalysts on spacer fabric: kinetic study and operational factors

In this study, the photocatalytic decolorization and mineralization of Remazol Black B (RBB), an azo reactive dye, in aqueous solutions was investigated using UV/H2O2/ZnO, UV/H2O2/TiO2 and UV/H2O2/ZnO:TiO2 systems. ZnO and TiO2 nanoparticles were loaded on 3-dimensional polyethylene terephthalate fabrics (spacer fabrics). Morphology of the spacer fabrics and the presence of the nanoparticles were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. Furthermore, the effects of key operational parameters on the efficiency of the decolorization were investigated. These parameters included initial pH value, initial hydrogen peroxide concentration, initial dye concentration, the loaded nanoparticle ratio and the presence of anions (sulfate, chloride and bicarbonate). Zero-, first- and second-order reaction kinetics were evaluated. Complete decolorization and high efficient mineralization with 90% total organic carbon (TOC) reduction were achieved at 120min treatment in the case of ZnO:TiO2 under optimum condition. The results proved that the novel heterogeneous photocatalytic process is capable of decolorizing and mineralizing azo reactive dyes in textile wastewater.

Change in dielectric properties in the microwave frequency region of polypyrrole-coated textiles during aging

Complex permittivity of conducting polypyrrole (PPy)-coated Nylon-Lycra textiles ismeasured using a free space transmission measurement technique over the frequency range of1–18 GHz. The aging of microwave dielectric properties and reflection, transmission and absorptionfor a period of 18 months is demonstrated. PPy-coated fabrics are shown to be lossy over thefull frequency range. The levels of absorption are shown to be higher than reflection in the testedsamples. This is attributed to the relatively high resistivity of the PPy-coated fabrics. Both the dopantconcentration and polymerisation time affect the total shielding effectiveness and microwave agingbehaviour. Distinguishing either of these two factors as being exclusively the dominant mechanismof shielding effectiveness is shown to be difficult. It is observed that the PPy-coated Nylon-Lycrasamples with a p-toluene sulfonic acid (pTSA) concentration of 0.015 M and polymerisation times of60 min and 180 min have 37% and 26% decrease in total transmission loss, respectively, upon agingfor 72 weeks at room temperature (20 C, 65% Relative humidity (RH)). The concentration of thedopant also influences the microwave aging behaviour of the PPy-coated fabrics. The samples with ahigher dopant concentration of 0.027 mol/L pTSA are shown to have a transmission loss of 32.6% and16.5% for short and long polymerisation times, respectively, when aged for 72 weeks. The microwaveproperties exhibit better stability with high dopant concentration and/or longer polymerization times.High pTSA dopant concentrations and/or longer polymerisation times result in high microwaveinsertion loss and are more effective in reducing the transmission and also increasing the longevity ofthe electrical properties.

Directional fluid transport in thin porous materials and its functional applications

Directional fluid motion driven by the surface property of solid substrate is highly desirable for manipulating microfluidic liquid and collecting water from humid air. Studies on such liquid motion have been confined to dense material surfaces such as flat panels and single filaments. Recently, directional fluid transport through the thickness of thin porous materials has been reported by several research groups. Their studies not only attract fundamental, experimental and theoretical interest but also open novel application opportunities. This review article summarizes research progress in directional fluid transport across thin porous materials. It focuses on the materials preparation, basic properties associated with directional fluid transport in thin porous media, and their application development. The porous substrates, type of transporting fluids, structure-property attributes, and possible directional fluid transport mechanism are discussed. A perspective for future development in this field is proposed.

Host and Network Optimizations for Performance Enhancement and Energy Efficiency in Data Center Networks

Modern data centers host hundreds of thousands of servers to achieve economies of scale. Such a huge number of servers create challenges for the data center network (DCN) to provide proportionally large bandwidth. In addition, the deployment of virtual machines (VMs) in data centers raises the requirements for efficient resource allocation and find-grained resource sharing. Further, the large number of servers and switches in the data center consume significant amounts of energy. Even though servers become more energy efficient with various energy saving techniques, DCN still accounts for 20% to 50% of the energy consumed by the entire data center. The objective of this dissertation is to enhance DCN performance as well as its energy efficiency by conducting optimizations on both host and network sides. First, as the DCN demands huge bisection bandwidth to interconnect all the servers, we propose a parallel packet switch (PPS) architecture that directly processes variable length packets without segmentation-and-reassembly (SAR). The proposed PPS achieves large bandwidth by combining switching capacities of multiple fabrics, and it further improves the switch throughput by avoiding padding bits in SAR. Second, since certain resource demands of the VM are bursty and demonstrate stochastic nature, to satisfy both deterministic and stochastic demands in VM placement, we propose the Max-Min Multidimensional Stochastic Bin Packing (M3SBP) algorithm. M3SBP calculates an equivalent deterministic value for the stochastic demands, and maximizes the minimum resource utilization ratio of each server. Third, to provide necessary traffic isolation for VMs that share the same physical network adapter, we propose the Flow-level Bandwidth Provisioning (FBP) algorithm. By reducing the flow scheduling problem to multiple stages of packet queuing problems, FBP guarantees the provisioned bandwidth and delay performance for each flow. Finally, while DCNs are typically provisioned with full bisection bandwidth, DCN traffic demonstrates fluctuating patterns, we propose a joint host-network optimization scheme to enhance the energy efficiency of DCNs during off-peak traffic hours. The proposed scheme utilizes a unified representation method that converts the VM placement problem to a routing problem and employs depth-first and best-fit search to find efficient paths for flows.

Information-agnostic coflow scheduling with optimal demotion thresholds

Previous coflow scheduling proposals improve the coflow completion time (CCT) over per-flow scheduling based on prior information of coflows, which makes them hard to apply in practice. State-of-art information-agnostic coflow scheduling solution Aalo adopts Discretized Coflow-aware Least-Attained-Service (D-CLAS) to gradually demote coflows from the highest priority class into several lower priority classes when their sent-bytes-count exceeds several predefined demotion thresholds. However, current design standards of these demotion thresholds are crude because they do not analyze the impacts of different demotion thresholds on the average coflow delay. In this paper, we model the D-CLAS system by an M/G/1 queue and formulate the average coflow delay as a function of the demotion thresholds. In addition, we prove the valley-like shape of the function and design the Down-hill searching (DHS) algorithm. The DHS algorithm locates a set of optimal demotion thresholds which minimizes the average coflow delay in the system. Real-data-center-trace driven simulations indicate that DHS improves average CCT up to 6.20× over Aalo.

Facile fabrication of polyester filament fabric with highly and durable hydrophilic surface by microwave-assisted glycolysis

Poly(ethylene terephthalate) (PET) fabric with highly and durable hydrophilic surface was fabricated using microwave-assisted glycolysis. Sodium hydroxide (NaOH) as a catalyst was proven to be suitable for PET glycolysis under assistance of microwave. The modified PET fabric (0.5% NaOH, irradiation 120 s) showed high surface hydrophilicity with a contact angle of 17.4 ° and a wicking length of 19.36 mm. The exposure of the carboxyl- and hydroxyl-end groups on the surface of PET and the introduction of etches were confirmed by Methylene Blue staining and field emission scanning electron microscopy (FESEM), receptively. Although the strength of PET fabric decreased after modification, it was still high enough for textile applications. The thermal properties of the modified PET fabrics were well maintained. The high hydrophilicity and its original properties of PET could be controlled by changing the irradiation time from 60 s to 120 s and adjusting the content of sodium hydroxide from 0.2% to 0.5%. These results suggest microwave-assisted glycolysis with sodium hydroxide is an effective method for PET hydrophilic finishing.

La montée du fascisme et de la Grande Dépression en Allemagne, vue par la presse de France, de Grande-Bretagne et des États-Unis (1930-32)

Dans les années 1931-32, les disputes à propos du traité de Versailles accompagnent la montée du fascisme et de la Grande Dépression en Allemagne. Les dirigeants anglosaxons ont justifié leur appui du Reich par leurs opinions publiques et des historiens ont expliqué que ces dernières s’étaient bercées d’illusions sur les enjeux allemands. Mais quelles étaient et d’où provenaient-elles ? Notre étude de quotidiens français, américains et britanniques montre qu’elles n’étaient pas uniquement constituées d’erreurs d’appréciation des réalités objectives, mais aussi de faits occultés, d’inventions, d’une guerre médiatique justifiant les choix de certains dirigeants financiers et politiques anglo-saxons. La diffusion rapide des mêmes inventions des deux côtés de l’Atlantique suggère l’existence de canaux de « fabrique d’opinions » entre l’Allemagne, la Grande-Bretagne, et les États-Unis.

Lusitanian Amphorae in Carthago Nova (Cartagena, Spain): Distribution and Research Questions

The presence of Lusitanian amphorae in the region of Carthago Nova (Cartagena, Spain) has been known for a few years, and yet it has never been the subject of a monographic study. Integrated in the commercial networks of the western Mediterranean, these products circulated within the harbour system of this city between the 1st and the 5th century AD. This paper aims to present a synthesised review of the main Lusitanian imports that were detected: Dressel 14 and Almagro 50, Almagro 51a-b and Almagro 51c. The difficulty in identifying the ceramic fabrics and the scarce documentation regarding some finds pose complex problems. This study extends to the hinterland of the colony and to other nearby settlements, such as Portmán and Puerto de Mazarrón.

Extensional orogenic collapse captured by strike-slip tectonics:

The late Paleozoic collision between Gondwana and Laurussia resulted in the polyphase deformation and magmatism that characterizes the Iberian Massif of the Variscan orogen. In the Central Iberian Zone, initial con- tinental thickening (D1; folding and thrusting) was followed by extensional orogenic collapse (D2) responsible for the exhumation of high-grade rocks coeval to the emplacement of granitoids. This study presents a tectonometamorphic analysis of the Trancoso-Pinhel region (Central Iberian Zone) to ex- plain the processes in place during the transition froman extension-dominated state (D2) to a compression-dom- inated one (D3).Wereveal the existence of low-dipping D2 extensional structures later affected by several pulses of subhorizontal shortening, each of them typified by upright folds and strike-slip shearing (D3, D4 and D5, as identified by superimposition of structures). The D2 Pinhel extensional shear zone separates a low-grade domain from an underlying high-grade domain, and it contributed to the thermal reequilibration of the orogen by facil- itating heat advection from lower parts of the crust, crustal thinning, decompression melting, and magma intru- sion. Progressive lessening of the gravitational disequilibrium carried out by this D2 shear zone led to a switch from subhorizontal extension to compression and the eventual cessation and capture of the Pinhel shear zone by strike-slip tectonics during renewed crustal shortening. High-grade domains of the Pinhel shear zone were folded together with low-grade domains to define the current upright folded structure of the Trancoso-Pinhel re- gion, the D3 Tamames-Marofa-Sátão synform. Newdating of syn-orogenic granitoids (SHRIMP U\\Pb zircon dat- ing) intruding the Pinhel shear zone, together with the already published ages of early extensional fabrics constrain the functioning of this shear zone to ca. 331–311 Ma, with maximum tectonomagmatic activity at ca. 321–317 Ma. The capture and apparent cessation of movement of the Pinhel shear zone occurred at ca. 317– 311 Ma.