Polyethylene Nail Brace for Ingrown Toenails Treatment: A Randomized Clinical Trial

Background: Onychocryptosis is one of the most prevailing onychopathies and one of the usual reasons for visiting podiatry clinics. In this research, we aim to evaluate the effectiveness of a procedure of nail reeducation technique via a strip of polyethylene in subjects with stage I or IIa onychocryptosis, in which pathological toenail curves are present. Methods: This research was a randomized clinical trial (ACTRN12615000834550). The sample was made up of 94 cases of stage I or IIa onychocryptosis, according to the Mozena classification. Briefly, 46 cases were treated with the combination of a spicule technique and nail brace with a polyethylene plastic strip, and 48 were only treated with the spicule technique. Results: The combination of the spicule technique and the nail brace technique with a strip of polyethylene had a significantly lower recurrence rate compared to that achieved with just the spicule technique, twelve months after the beginning of the study (N.S. = 0.000 for α = 0.05). The change in the nail width achieved with the nail brace technique, twelve months after the beginning of the study, was statistically significant (N.S. = 0.000 for α = 0.05). Conclusions: The recurrence rate of the spicule technique alone was significantly higher than the combined technique of spicule with nail brace. A nail brace with a strip of polyethylene reduces the recurrence rate of onychocryptosis.

A Flow in a Thin Plastic Layer: Generalizations of the Prandtl’s Problem

The analytical solutions of various generalizations of the classical L.Prandtl’s problem are of great interest in studying the problem of straightening plates using uniaxial stretching beyond the elastic limit. The straightening by stretching allows obtaining a high degree of flatness of thin wide strips and sheets of high-strength steels and special alloys, while the straightening by other methods does not provide satisfactory results. Based on Ilyushin’s theory of flow in a thin plastic layer, generalizations of the classical Prandtl’s problem on plastic strip compression were studied and their solutions were obtained. The planar problem of compression of a plastic strip between two parallel rough planes with accounting for the asymmetry of the conditions on the spreading ends has been solved and the upper estimate of the total compression force of the face-end areas of the plastically stretched strip has been obtained.

Imposed curvature of an elastic-plastic strip: application to simulation of coils

This work is part of the framework of a fast modeling of winding aiming at improving knowledge of residual stress evolution in steel strips and therefore their flatness during the coiling process. An exact analytical solution of an elastic-plastic strip with isotropic hardening at finite strains under an imposed transformation of curvature is developed. Issues related to flow rules for non-differentiable yield functions (Tresca) have been broached and a unique solution is obtained. The equivalence for this transformation, between von Mises and Tresca yield functions is demonstrated. This solution contributes to an efficient model by terms of computation times that aims at simulating coiling by taking into account inelastic deformations and enabling parametric studies in order to improve the process.

Photochromic and Thermochromic Colorants in Textile Applications

Commercial photochromic and thermochromic colorants that change rapidly and reversibly from colorless to colored state when activated by stimuli like ultraviolet irradiation, temperature or pH are well established class of colorants for manufacturing of niche products. Use of photochromic and thermochromic systems in applications like medical thermography, plastic strip thermometers, photochromic lenses, food packaging and nondestructive testing of engineered articles and electronic circuitry is well documented. However, in the last few years, the research on application of these systems on textiles has picked up significantly which has the potential to unlock commercially significant nascent high-tech applications. This review paper presents a summary of the chemistry, mechanism, application on textiles and evaluation procedure of performance, other technical features, current and potential application areas as well as challenges encountered in wider acceptance of photochromic and thermochromic colorants on textiles.

A mm-Scale Aeroelastic Oscillation-Based Anemometer

By combining the aeroelastic and vortex-forced flutter modes of a thin plastic strip, its oscillation frequency can be confined to scale monotonically with fluid velocity. This principle has been used to produce a low-cost, mm-scale anemometer that measures air speed to ±(5% + 0.5m/s) from 1–18m/s. The device uses a 2mm slot-type photointerrupt detector to monitor the fundamental frequency of a 7μm thick Kapton strip suspended parallel to air flow. This paper describes the prototype and three of the experiments that informed its design. These investigated the effect of a bluff body on flutter onset velocity, the effect of filament geometry on bending position, and the effect of the superposition of the vortex-forced and aeroelastic flutter modes on discretely-measured flutter frequency. The experiments demonstrate that a trapezoidal filament in the wake of a similarly-sized bluff body is well-suited for this novel flow measurement strategy.

The yield condition strongly influences the formation of Dugdale plastic strips ahead of crack tips under tensile plane stress loading conditions

A finite element analysis indicates a good correlation between the Dugdale plastic strip model and a linear elastic/perfectly plastic material under plane stress loading conditions for a flow theory of plasticity based on the Tresca yield condition. A similar analysis under the von Mises yield condition reveals no plastic strip formation.