Multi-jet electrospinning of polystyrene/polyamide 6 blend: thermal and mechanical properties

Citation: Yoon, J. W., Park, Y., Kim, J., & Park, C. H. (2017). Multi-jet electrospinning of polystyrene/polyamide 6 blend: thermal and mechanical properties. Fashion and Textiles, 4, 12. doi:10.1186/s40691-017-0090-4Polystyrene (PS) has high thermal resistance thus can be applied as thermally comfortable textile. However, the application is limited due its low mechanical strength. In this study, polyamide 6 (PA6) was blended with PS to improve the mechanical strength of PS, by means of a multi-jet electrospinning. Content ratio of the blend web was measured by chemical immersion test and confocal microscopy analysis. Fiber content was in accordance with the number of syringes used for PS and PA6 respectively. The effects of content ratio on the web morphology, thermal resistance, tensile behavior, air and water vapor permeability, and surface hydrophilicity were investigated. The influence of environmental humidity during electrospinning process on three dimensional (3D) web structure was also reported. PS web produced from higher humidity had more pores and corrugations at the surface. The increased surface roughness and porosity led to the increased hydrophobicity and thermal resistance. Though the blending of PA6 with PS enhanced the mechanical strength, the added PA6 decreased air/water vapor permeability and thermal resistance. The lowered thermal resistance by the addition of PA6 was mainly attributed to higher thermal conductivity of PA6 material and lowered air content with PA6 fibers

Removal of Pb and Cu ions from aqueous solution by Mn3O4-coated activated carbon

Mn3O4-coated activated carbon (Mn3O4/AC) was prepared by supercritical technique and applied for the removal of Pb and Cu ions from aqueous solution. Kinetic and isotherm data of the adsorption by Mn3O4/AC were compared with those of activated carbon (AC) and pure Mn3O4. Adsorption of metals was adequately described by pseudo-second-order kinetics and Langmuir isotherm models. Maximum adsorption capacities of Pb and Cu ions determined by Langmuir model were enhanced 2.2 and 6.1 times for Pb and Cu ions by Mn3O4 coating onto AC, which might be attributed to reduced resistance of intraparticle diffusion and enhanced surface electrostatic interaction and complexation by Mn3O4

Unusual extraction treatment in Class II division 1 using C-orthodontic mini-implants.

AbstractThis paper describes the treatment of a female patient, aged 23 years and 5 months, with a Class II division 1 malocclusion, who showed severe anterior protrusion and lower anterior crowding. Specially-designed orthodontic mini-implants were placed bilaterally in the interdental space between both the upper and the lower posterior teeth. Both lower first molars showed severe apical lesions. Therefore, the treatment plan consisted of extraction of both upper first premolars and lower first molars, en masse retraction of the upper six anterior teeth, lower anterior alignment, and protraction of all the lower molars. C-implants® were used as substitutes for maxillary posterior anchorage teeth during anterior retraction and as hooks for mandibular molar protraction. The correct overbite and overjet were obtained by intruding and retracting the upper six anterior teeth into their proper positions. The dentition was detailed using conventional orthodontic appliances. The upper C-implants contributed to an improvement in facial balance, and the lower C-implants made it possible to protract the lower second and third molars with less effect on the axis of the lower anterior teeth. The active treatment period was 29 months and the patient's teeth continued to be stable 11 months after debonding

Measuring the maturity of open access: a preliminary study

Open access is an important part of scholarly communication, and it has been a global phenomenon. The growth of open access brings several signif-icant benefits to the general public as well as researchers, ultimately leads to the advancement of science. For the continuous growth and development of open access, it is necessary to measure the degree of maturity of open ac-cess. However, there is not much discussion about the assessment frame-work for open access. This study aims to propose an assessment framework of open access maturity. For the purpose of this study, we conducted an analysis with a total of 24 literatures relevant to the digital maturity, the ma-turity of open data/open science, and major open access initiatives. For digi-tal maturity, 18 articles were analyzed: 10 articles for generic purpose model, and 8 articles for industry-specific model. In addition, three articles on the maturity of open data/open science were analyzed and three major open ac-cess initiatives. In preliminary analysis results, three dimensions with 13 be-longing items were proposed for measuring the maturity of open access. Three dimensions are OA Policy, OA capability, and Openness quality. For OA policy, there are three items such as OA policy document, OA govern-ance, and OA strategy. For OA Capability, finance for OA, people for OA, culture for OA, and collaboration for OA are proposed. For Openness Quali-ty dimension, six items are suggested: submission and review, author rights, user rights, findability, accessibility, and monitoring

Catalytic Performance for Hydrocarbon Production from Syngas on the Promoted Co-Based Hybrid Catalysts; Influence of Pt Contents

Fischer-Tropsch synthesis (FTS) reaction from syngas was investigated on the Pt-promoted cobalt-based hybrid catalysts prepared by co-precipitation method in a slurry of ZSM-5 (Si/Al=25). The hybrid catalysts were compared with each other for the different content of Pt as a promoter and are characterized using BET, XRD, H2-TPR and NH3-TPD. Their physicochemical properties were correlated with the activity and selectivity of the catalysts. As results, all hybrid catalysts show the C5-C9 yield (%) higher than that of Co-Al2O3/ZSM-5 catalyst. The Pt-promoted hybrid catalysts were found to be more promising towards production of the hydrocarbons of gasoline range and over C10.