Potentials of lignocellulosic agricultural residues in paper production

Surface characteristics of printing substrates are of the utmost importance to all types of paper that interact with ink. During all types of printing processes, the behaviour of the liquid phase (ink or dye) on the paper is directly defined by the paper cellulose-based surface. The printed ink spreads and penetrates more into paper fibres when the paper surface is rougher and more permeable. Contact angle measurements by sessile drop method are considered the most appropriate for determining the paper sheet surface energy. Paper as hydrophilic material has a high absorption rate resulting in a low contact angle. The objective of this study was to evaluate the surface free energy of laboratory-made papers containing straw pulp obtained from residues after the harvest of the most cultivated cereals in Croatia (wheat, barley and triticale). The obtained surface free energy results are promising for straw pulp usage in the manufacture of printing paper.

Weight of Different Intraocular Lenses: Evaluation of Toricity, Focality, Design, and Material

Purpose. To evaluate the weight of intraocular lenses (IOLs) depending on their material, dioptric power, toricity, focality, and haptic design. Methods. Twenty-eight different IOL models from nine different medical companies (a total of 38 IOLs) and 1 capsular tension ring (CTR) were evaluated. IOLs were weighed using a precision scale, in hydrated conditions, as an approximation to their intraocular status. Results. Hydrophilic IOLs were heavier than hydrophobic lenses ( p < 0.001 ). Regarding toricity, no statistical differences were found comparing toric to non-toric models ( p = 0.1 ). Likewise, no differences were found between multifocal IOLs and monofocal IOLs ( p = 0.19 ). Dioptric power did not affect IOL weight: IOLs of <15DP had similar weights to those of ≥15D and IOLs of ≥24D had similar weights to those of <24 D ( p = 0.86 and p = 0.59 , respectively). Plate-design IOLs were significantly heavier than 1-piece C-loop ( p < 0.001 ), 3-piece C-loop ( p < 0.001 ), and 4-haptic lenses ( p = 0.001 ). Conclusions. Of the characteristics analyzed that might influence IOL weight, lenses with hydrophilic material and plate-haptic design were found to be heavier. Toricity, focality, and dioptric power had no influence on IOL weight.

Hybrid contact lenses for the correction of primary and induced ametropias

The review presents the data on the use of hybrid contact lenses (HCL), a modern method of contact correction of ametropias of diverse origins. A HCL has a central rigid optical zone made of highly gas-permeable material and a flexible peripheral part made of hydrophilic material. These lenses combine the optical effect of gas-permeable corneal lens with the comfort and stable fitting of soft contact lenses. Compared with the corneal (RGP) lenses, HCLs are more comfortable, often are better centrated and more stably fit on the eye. HCLs are successfully used in various refractive disorders: ametropias (with regular cornea), irregular astigmatism, presbyopia, including that combined with astigmatism. This type of lens is a good option of contact correction for patients who have high requirements to the quality of vision.

On the wetting translucency of hexagonal boron nitride

When a drop sits on an atomically thin coating supported by a hydrophilic material, it is possible that the underlying substrate influences the equilibrium contact angle. Such behavior is known as the wetting translucency effect.

Adhesive-related warping of thin wooden bi-layers

Warping of layered wood-based panels is still a challenging problem in the development of thin engineered wood products. Wood as an anisotropic and hydrophilic material tends to change its volume and mechanical properties with changing moisture content. Besides the wood components, also the mechanical properties of certain adhesives are sensitive to moisture changes. A moisture load onto the adhered wood is resulting in different stress and strain states between the adherends. It is expected that adhesives with different moisture-related properties participate differently to this interaction. To observe an adhesive-related warping, thin spruce/HDF (Picea abies and high-density fibreboard) bi-layers with identical material geometries were manufactured under laboratory conditions, using different wood adhesive systems, which are currently used in furniture and flooring industry [polyurethane (PUR), emulsion polymer isocyanate (EPI), polyvinyl acetate (PVAc), urea formaldehyde (UF) and ultra-low emitting formaldehyde amino adhesive (ULEF)]. The bi-layers were exposed to certain relative humidity conditions, and the resulting deformation was measured with a high-precision laser distance detector. Moisture-dependent warping of the bi-layers was obtained in relation to the used adhesive systems. As a result of the study, it can be shown that initial warping after panel manufacturing strongly depends on the adhesive curing characteristics and, especially, on the amount of water that is released into the wood adherend. For the post-setting panel warping, a differentiation into two adhesive groups became visible: rigid and flexible adhesives. Rigid adhesives (UF and ULEF) showed a higher degree of warping compared to the group of flexible adhesives (PUR, EPI and PVAc).

Experience in application of hybrid contact lenses for astigmatism correction

The review covers the issue of hybrid contact lenses application as one of the modern contact correction methods in patients with ametropias of various genesis. Hybrid contact lenses consist of a rigid central optical part made of highly gas-permeable material and a flexible peripheral part made of hydrophilic material. These lenses combine the optical correction qualities of gas-permeable corneal lenses with the comfort and stable fit usually provided by soft contact lenses. Compared to gas-permeable corneal lenses, hybrid lenses are more comfortable; often have better centration and more stable fit on the eye. Hybrid contact lenses successfully correct both types of astigmatism: regular and irregular. This type of lenses is a good alternative method of contact correction for patients who place heavy demands in terms of the quality of vision.

Surface Properties of Pine Scrimber Panels with Varying Density

Coating quality for scrimber products against exterior conditions is largely dependent on the surface properties. The wettability, morphology, and chemical composition of pine scrimber surfaces were investigated to better understand the surface properties. The scrimber was found to be a hydrophilic material because the water contact angles were less than 90°. The panels with a density of 1.20 g/cm3 had the largest angle change rate (k = 0.212). As the panel density increased, the instantaneous contact angle of each test liquid (i.e., water, formamide, and diiodomethane) on the panels decreased, and so did surface free energy. Panels with higher density showed lower surface roughness. Surface roughness across the wood grain was greater than that along the grain. SEM observations showed the high-density panels had a smoother surface with fewer irregular grooves in comparison with the low-density panels. X-ray photoelectron spectroscopy (XPS) analysis indicated that more unoxygenated groups appeared on the surface of high-density panels.

A magnetic nanofiber-based zwitterionic hydrophilic material for the selective capture and identification of glycopeptides

A magnetic nanofiber-based zwitterionic hydrophilic material with excellent performance and practical potential for capturing and identifying glycopeptides has been developed.