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Nano-Finishing on Woolens
Published in Prashansa Sharma, Devsuni Singh, Vivek Dave, Fundamentals of Nano–Textile Science, 2023
Ajay Kumar, D.B. Shakyawar, Seiko Jose, Vinod Kadam, N. Shanmugam
Barani et al. (2014) applied AgNPs/Lecithin on wool fabric for imparting antibacterial properties. The scoured fabric is treated with both pad-dry-cure and exhaust method. In pad-dry-cure wool fabric were impregnated in AgNPs/Lecithin with M:L Ratio of 1:40 for 15 min. In colloidal AgNPs, dispersion was found to have a silver content of 300 ppm and lecithin to silver ratio varied to 0, 0.2, 1, and 2. The fabrics were squeezed to 80% wet pick-up and dried at 80°C for 20 min, followed by curing at 130°C. In exhaust method MLR was kept the same and the scoured fabric was introduced in the bath at 40°C. The treatment was performed at 90°C for another 30 min. The treated wool fabrics were then washed and dried at 80°C. The bactericidal properties of AgNPs-loaded wool fabrics were evaluated against gram-positive and gram-negative bacteria, S. aureus and E. coli, respectively. Fabrics with high silver content showed the larger inhabitation zone. The antibacterial efficacy of AgNPs is found more with exhaust treated fabrics. The bacterial reduction efficiency for exhaust treated wool fabric against S. aureus increased from 91.15% to 98.8% compared to pad-dry cure method treated fabrics which showed bacterial reduction from 40.55% to 97.3%. The antibacterial efficiency against gram-negative bacteria (E. coli) for the same lecithin to silver ratio was observed to increase from 18.1% to 87.3% for exhaust treated fabrics, and for a lecithin to silver ratio of 2 with pad-dry-cure method only to 61.2%.
Microstructured fiber hydrogen-sensing based on optimized Pd-Ag film
Published in Gin Jose, Mário Ferreira, Advances in Optoelectronic Technology and Industry Development, 2019
X. Zhou, M. Yang, K.F. Liu, X.Z. Ming, R. Fan, Y.T. Dai
At present, there are many kinds of hydrogen-sensitive materials, such as pure palladium and various palladium alloys. After pure palladium has undergone several cycles of absorbing and releasing hydrogen, a palladium film is prone to cracking or detachment from the surface of a fiber due to phase transition of the Pd film (Ma et al., 2012). In addition, a hydrogen sensor with a pure palladium membrane has a long response time. Therefore, metals such as nickel, silver, and gold are usually incorporated into palladium to form Pd-Ag (Faizal et al. 2015), Pd-Ni (Jiang et al., 2015), and Pd-Au alloy films that can suppress the palladium phase transition (Luna-Moreno & Monzón-Hernández, 2007). Because palladium-silver alloy membranes have better hydrogen selectivity and permeability, it is chosen as a hydrogen-sensitive material by many people. Sharma and Kim (2017) prepared a microelectromechanical (MEMS) hydrogen sensor using a palladium-silver ratio of 77:23. Dai et al. (2013) used a 76:24 ratio of Pd-Ag to prepare a hydrogen sensor. The Pd-Ag film was coated on the FBG surface, which had a diameter of 20.6 μm, and the wavelength shift of the sensor was 40 pm at 4% hydrogen concentration. Jiang et al. (2015) prepared a hydrogen sensor with a palladium-silver ratio of 3:1 composite film on a show side-polished FBG and detected the hydrogen content in oil. Because the ratio of palladium-silver alloy directly affects the sensing sensitivity and response time, it is necessary to explore the influence of different palladium and silver content on the performance of the sensor.
Arc Interactions with Contaminants
Published in Paul G. Slade, Electrical Contacts, 2017
Gerald J. Witter, Werner Rieder
Figure 19.7 is an SEM micrograph of the edge of an area from a single arc. SiC particles, triangular crystalline particles, can be seen embedded in the surface just outside the arced area and the silver-silicon oxide aggregates made of round and amorphous-shaped particles can be seen in the arced area. The arced area is very rough compared to the unarced surface and the individual particles making up the aggregates vary in composition with regard to the silicon to silver ratio. Although the surface is rough, there is no benefit as predicted by Williamson’s work [48], since the aggregates form heaps that are significantly elevated above the unarced surface and the constriction areas are complex with current paths going through a series of many particles and interfaces making up the aggregate heaps. As a result of this, the contact resistance remains elevated but significantly variant as a function of the path required from the contact spots through this thick upraised resistive layer. The contact resistance initially increases with switching operations owing to increased refractory build up on the surface. Depending on the current level and the contamination concentration the resistance begins to decrease at some operation point as the refractory material is gradually eroded away through arc erosion.
Metal borate nanostructures for industrial antibacterial ceramic fabrication
Published in Inorganic and Nano-Metal Chemistry, 2021
Osman Aguş, Osman Arslan, Yüksel Abalı
Surprisingly, XRD peaks unveiled that by enhancing the temperature, the peak density of the synthesized particles increased. It is likely excessive anions of borate ions are governing the solution dynamics by changing the hydrogen concentration, flux rate, and appropriate complex formation. The most salient note which can be derived from the reactions is that the formation and crystallinity of silver borate occur at increasing temperatures and role of the mole ratio seems ineffective in the same regions. The intensity of XRD patterns was expressively increased with the increasing temperature. The effect of temperature speeds up formation of the particle conditions such as formation of extremely crystalline structures, increased atomic diffusion, increased saturation, and sufficient flux ratio in solution (Figure 3b–e). In Figure 3b–e, all the peaks were analyzed according to the varying mole ratios. This means, silver and borax ratios were kept stable with four different applications. In Figure 3b, Ag/borax ratio was 1/2 and it is easily seen that increasing temperature forms a very high crystallinity. Figure 3c,d show that if the ratio was changed to 1/1.5 and 1/1, formation of the silver borate at low temperatures is very sensitive and especially 1/1.5 has a very low crystallinity. Still when the silver ratio increases to 2 versus borax 1, as in Figure 3e, quite perfect crystal structures are observed. If one compares all the 16 XRD investigations here, it is obvious that temperature regulates the real silver borate crystal formation and mole ratio is actually not effective as much as the temperature.
Parameters for the formation of orogenic gold deposits
Published in Applied Earth Science, 2019
Nevertheless, if thermodynamic modelling of fluid generation accounts well for the metamorphic sources, in some cases, magmatic fluids were also involved (Yardley and Cleverley 2015). These deposits commonly contain a granitophilic suite of elements including Bi, Te, As, Mo, Sb, Sn and W (Thompson et al. 1999; Helt et al. 2014), and accordingly, some fall within the intrusion-related type. This debate was addressed two decades ago (Sillitoe and Thompson 1998; Groves et al. 2003) and remains today. For example, Xue et al. (2013), based on S isotopes (32S, 33S, 34S) of pyrite in four Archaean orogenic gold deposits, suggested a granitic source for the fluids. With the accumulation of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses from pyrite in orogenic gold deposits, it is now obvious that some deposits with typical characteristics of orogenic gold deposits recorded sporadic magmatic fluid and gold contributions. As example, LA-ICP-MS pyrite mapping shown that gold is associated with silver (ratio of Au/Ag < 5) and with higher contents of granitophilic elements surrounding gold grains, especially Bi, Te, Mo, Sn and W (Augustin and Gaboury 2019).
Tunable near-infrared epsilon-near-zero and plasmonic properties of Ag-ITO co-sputtered composite films
Published in Science and Technology of Advanced Materials, 2018
Chaonan Chen, Zhewei Wang, Ke Wu, Hui Ye
The results are summarized as the dotted lines in Figure 5(b)–(d), which show reflectance curves for Ag-ITO films with various silver ratios. Rp and Rs, the reflectance spectra of TM-polarized and TE-polarized light were obtained respectively and are calculated as the ratio of Rp/Rs. We use this ratio for further analysis since Rs is without characteristics at this spectra [45]. Previously, the observation of broad SPP dips in pure TCO films has been reported [36,40,45,46]. Those discussions illustrated wavelength-of-incidence-, material-, and thickness-dependent SPP resonances and as a supplement, our study clearly shows the SPP existence on Ag-ITO composite films as a function of silver ratio. For each curve, the total internal reflection appears at about 44°. The reflectance dips, from 52° to 56° when increasing silver ratio from 0.15 to 2.74 at.%, reveal pronounced SPP resonances. Besides, the depth of the dips is related to the imaginary permittivity ε″ of the films, i.e. smaller ε″ means less dissipative loss, which indicates that more energy can be sustained to excite SPP and larger dip will be observed. For SPR motivation, the ideal material is lossless metallic component. The reflectance curve will then be a narrow and sharp dip at the resonance wavelength. Large ε″ (large loss) will not lead to lower dip reflectance, but weakens the SPR effect which will be directly seen from the shallowing depth and broadening width of the reflectance dip. So, the dips for samples with less silver content are deeper.