Exploring the transverse wicking behavior of mechanically robust warp super-elastic woven fabric for tight-fitting garments

The ability of a fabric to wick moisture away from the human body directly determines the moisture management ability of any given textile, and thereby has a great influence on the comfort offered by garments made from that textile. In this paper, the effects of tensile extension and liquid drop height on the transverse wicking behavior of a warp stretch woven fabric were systematically investigated. By virtue of the unique structure of the nylon/spandex air-covered warp yarn, the woven fabric has a denser and tighter surface, which facilitates its warp elastic stretchability beyond 60%. Furthermore, an acceptable cyclic tensile behavior at an extension of 30% was obtained, indicating the superior mechanical robustness of the fabric to a certain extent. The experimental results demonstrated that the transverse wicking performances of the fabric, including the wetting time and liquid spreading area, were dependent on the tensile extensions and the heights between the water droplet and the fabric surface. Specifically, the wetting time increased with an increase of tensile extension or a decrease of liquid drop height. The spreading area of the water droplet increases as a function of the wicking time, and it fits a power relation appropriately. In addition, the water vapor transmission behavior of our fabric during stretch was clarified. Such work is essential to get an in-depth evaluation of the wicking behavior of complex stretchable fabric structures.

The relational and normative accommodation to the school environment of the pupils from traditional and step by step classes

Beginning from the presence of Step by Step educational alternative at the level of the Romanian educational space, from its spreading area and from its defi nitive specifi c aspects which this alternative illustrates at the level of the instructive-educative process, we decided to approach a comparative study between this educational alternative and the traditional educational system on the direction of pupils’ relational and normative accommodation inside the school environment. We can diff erentiate the following indicators for relational accommodation dimension: pupils’ relational behaviour and their capacity to communicate with peers and teachers. Used instruments: questionnaire (questions II and III). The obtained results can determine if this educational alternative is suitable for our country educational system. Within the Step by Step pattern, in the fi rst grade, the number of pupils who manage to do this is 10, which is 20.8%, in the second grade, the number rises to 25, which is 52.1%, while in the third grade the number rises to 35 pupils, which constitutes 72.9%.

Temporal rings with spiral ornamentation: the spreading area and chronology

The paper considers one of the categories of medieval jewelry – temporal rings with décor made of spirally twisted wire. The study characterizes finds from Eastern Europe known to date and provides data on jewelry from Central and South-Eastern Europe. The temporal rings of different design of their ends and spiral decorations are identified. Jewelry of this type is associated with the Byzantine jewelry tradition. The finds are concentrated in Slavic sites along the Danube, in Serbia, Bulgaria and Southeast Romania. They are not numerous in Central and Eastern Europe. Their chronology, as in the Danube-Balkan region, covers the 10th–14th centuries, the largest number of finds belonging to the second half of the 11th–13th century. Rings with a spiral decor could enter Northern Rus both as a result of trade and with settlers from the southern Rus lands. A small number of finds indicate that this type of jewelry did not become the subject of mass production outside the Danube-Balkan region.

Formulation of Toothpaste Toothpaste Gel Essential Oil of Lime Leaves (Citrus Aurantifolia) With Variations Concentration of Carbomer 940 As Gelling Agent Base

Background : Lime leaves contain flavonoids, tannins, and saponins. This content is known to have activity as an antibacterial and protective of gums and teeth. Based on these activities, lime leaves can be developed as an active ingredient in gel toothpaste preparations. In the manufacture of gel toothpaste, the component that plays an important role is the gelling agent. Purpose: In this study, a variation of the gelling agent Carbomer 940 will be used to make a gel toothpaste with lime leaf extract. Methods: The independent variable used is Carbomer 940 with a variation of 3 formulas, namely 0.6%; 1.2%; and 1.8%. The evaluations carried out on gel toothpaste were organoleptic, homogeneity, pH, adhesion, spreadability and pH. Data analysis was carried out with SPSS software to see the differences between each formula. Results: The results showed that the formula 1-3 was homogeneous with a clear, homogeneous color, and a characteristic smell of menthol with a pH range of 5.85-7.49; spreading area 20.60-29.91 cm2, adhesion 6.01-35.1 seconds. The results of statistical tests with one-way ANOVA obtained a significant difference between each formula.

Surfactant-Induced Reconfiguration of Urea-Formaldehyde Resins Enables Improved Surface Properties and Gluability of Bamboo

The high-efficiency development and utilization of bamboo resources can greatly alleviate the current shortage of wood and promote the neutralization of CO2. However, the wide application of bamboo-derived products is largely limited by their unideal surface properties with adhesive as well as poor gluability. Herein, a facile strategy using the surfactant-induced reconfiguration of urea-formaldehyde (UF) resins was proposed to enhance the interface with bamboo and significantly improve its gluability. Specifically, through the coupling of a variety of surfactants, the viscosity and surface tension of the UF resins were properly regulated. Therefore, the resultant surfactant reconfigured UF resin showed much-improved wettability and spreading performance to the surface of both bamboo green and bamboo yellow. Specifically, the contact angle (CA) values of the bamboo green and bamboo yellow decreased from 79.6° to 30.5° and from 57.5° to 28.2°, respectively, with the corresponding resin spreading area increasing from 0.2 mm2 to 7.6 mm2 and from 0.1 mm2 to 5.6 mm2. Moreover, our reconfigured UF resin can reduce the amount of glue spread applied to bond the laminated commercial bamboo veneer products to 60 g m−2, while the products prepared by the initial UF resin are unable to meet the requirements of the test standard, suggesting that this facile method is an effective way to decrease the application of petroleum-based resins and production costs. More broadly, this surfactant reconfigured strategy can also be performed to regulate the wettability between UF resin and other materials (such as polypropylene board and tinplate), expanding the application fields of UF resin.

Effect of In and Pr on the Microstructure and Properties of Low-Silver Filler Metal

The novel low-silver 12AgCuZnSn filler metals containing In and Pr were used for flame brazing of copper and 304 stainless steel in this study. The effects of In and Pr content on the melting temperature, wettability, mechanical properties and microstructure of 12AgCuZnSn filler metal were analyzed. The results indicate that the solidus and liquidus temperatures of filler metals decrease with the addition of In. Trace amounts of Pr have little impact on the melting temperature of the low-silver filler metals. In addition, the spreading area of filler metals on copper and 304 stainless steel is improved. The highest shear strength of brazed joint is 427 MPa when the content of In and Pr are 2 wt.% and 0.15 wt.%, respectively. Moreover, it is observed that the trace amount of Pr significantly refines the microstructure of brazed joint matrix. A bright Pr3Cu4Sn4 phase is found in filler metal and brazing seam when the contents of In and Pr are 5 wt.% and 0.5 wt.%, respectively.

Effects of surface roughness on CMAS corrosion behavior for thermal barrier coating applications

Calcium-magnesium-alumina-silicate (CMAS) corrosion is an important cause for thermal barrier coating (TBC) failure, which has attracted increased attentions. In this study, some thermal barrier coating (TBC) materials including YSZ (yttria partially stabilized zirconia), GdPO4, and LaPO4 were prepared into bulks, and the effects of their surface roughness on wettability and spreading characteristics of molten CMAS were investigated. As-fabricated and polished bulks with different surface roughness were exposed to CMAS corrosion at 1250 °C for 1 and 4 h, following by macro and micro observations. Results revealed that compared with the as-fabricated bulks, molten CMAS on the polished samples had lower wettability and a smaller spreading area, mainly attributable to the reduced capillary force to drive the melt spreading. Meanwhile, GdPO4 and LaPO4 bulks exhibited lower CMAS wettability than YSZ bulk. It is thus considered that reducing the surface roughness is beneficial to CMAS corrosion resistance of TBCs.

Spreading behavior of firefighting foam solutions on typical liquid fuel surfaces

A series of experiments was performed to investigate the spreading behavior of firefighting foam solutions on liquid fuel surfaces. The spreading coefficients of six kinds of aqueous film-forming foam solutions and one fluorine-free foam solution on the surface of four liquid fuels, namely, cyclohexane, diesel, n-heptane, and ethanol, were calculated on the basis of surface and interfacial tension. Spreading behavior was studied systematically using a high-speed camera, and then the relationship between spreading behavior and spreading coefficient was analyzed. Furthermore, the spreading area and spreading rate of different foam solution droplets on liquid fuel surfaces were studied in depth. The spreading amount of the foam solution droplets on the liquid fuel surfaces was measured. Four typical spreading phenomena, namely, spreading, suspension, dissolution, and sinking, of AFFF solutions on liquid fuel surfaces were identified. Moreover, a positive spreading coefficient did not necessarily lead to the formation of an aqueous film. The spreading area, spreading rate, and spreading amount were not proportional to the spreading coefficient. During the evaluation of the spreading property of firefighting foam, the spreading coefficient, spreading rate, and spreading amount must be focused on instead of only the spreading coefficient.

Effect of Various Nanoparticles (GaF3, ZnF2, Zn(BF4)2 and Ga2O3) Additions on the Activity of CsF-RbF-AlF3 Flux and Mechanical Behavior of Al/Steel Brazed Joints

In this study, brazing AA6061 to Q235 steel using flame brazing was performed with 70.9 wt.% CsF-0.5 wt.% RbF-28.6 wt.% AlF3 fluxes doped with GaF3, ZnF2, Zn(BF4)2 and Ga2O3 nanoparticles, matched with a Zn-15Al filler metal, and the spreadability of the filler metal and the mechanical properties of brazed joints were investigated at the same time. The results showed suitable amounts of GaF3, ZnF2, Zn(BF4)2 and Ga2O3 doped into the base flux could strengthen the filler metal in wetting and spreading on the surface of aluminum alloy and steel to different degrees. The suitable ranges of GaF3, ZnF2, Zn(BF4)2 and Ga2O3, respectively, were 0.0075–0.01 wt.%, 0.0075–0.01 wt.%, 0.0075–0.01 wt.% and 0.009–0.01 wt.%, and the maximum spreading area was obtained via doping with GaF3. The shear strength of brazed joints reached the peak at 126 MPa when 0.075 wt.% GaF3 was added. Comparative tests proved that the activity of the CsF-RbF-AlF3 flux doped with GaF3 was the best. The reason was that the CsF-RbF-AlF3-GaF3 flux was competent in removing oxides of the base metal and decreasing the interfacial tension, in virtue of the activity of Ga3+ as well as F−.