Influence of Convective and Radiative Cooling on Heat Transfer for a Thin Wire with Temperature-Dependent Thermal Conductivity

In this study, a numerical prediction of temperature profiles in a thin wire exposed to convective, radiative and temperature-dependent thermal conductivity is carried out using a finite-difference linearization approach. The procedure involves a numerical solution of a one-dimensional nonlinear unsteady heat transfer equation with specified boundary and initial conditions. The resulting system of nonlinear equations is solved with the Newton-Raphson’s technique. However unlike the traditional approach involving an initial discretization in space then in time, a different numerical paradigm involving an Euler scheme temporal discretization is applied followed by a spatial discretization. Appropriate numerical technique involving partial derivatives are devised to handle a squared gradient nonlinear term which plays a key role in the formulation of the Jacobian matrix. Tests on the numerical results obtained herein confirm the validity of the formulation.

Investigation of the workability and surface roughness of thin brass wires in various dieless drawing technologies

Possibilities of improving the workability of the CuZn37 brass thin wire in a diameter of 0.14–0.18 mm produced by the dieless drawing processes were explored. The workability was defined as the maximum final longitudinal strain of the wire up to its fracture, achievable in the dieless drawing process. Two technologies of dieless drawing were developed and their workability was compared. The first one is the classical one-pass process; the second, a multi-pass one. For both developed technologies, it was possible to obtain a good-quality product but more than two times higher workability has been demonstrated for the multi-pass technology. No evident effect of the deformation temperature from the window of technologically accepted parameters on the workability was found but an increase in the temperature significantly increased the roughness of the product surface. For the same deformation temperature, the roughness of the wire obtained from the multi-pass process appeared to be significantly lower than for the one of the classical one-pass technologies.

Radiofrequency Energy-Assisted Wire Atrial Septostomy to Easily Create a Large Atrial Septal Defect

Wire atrial septostomy, a new transcatheter technique, combines 2 atrial septal defects (ASDs) into a large one in a thickened atrial septum. Although the thin-wire-looped atrial septum between ASDs needs to be pulled deeply into a hard catheter to tear the septum, this action might harm the surrounding cardiac structures. We utilized radiofrequency wire energy to facilitate the tearing of the septum, making the procedure easier and safer. This technical article presents the modified procedure in detail; the procedure was performed in a 6-month-old boy with double outlet right ventricle and intact ventricular septum. Mini-abstract This technical article describes modified wire atrial septostomy for thickened atrial septum in detail. Radiofrequency energy facilitated a thin wire-loop in tearing the septum between 2 atrial septal defects to combine the defects into a large one. We believe that this transcatheter procedure is easier and safer than the original one not using a radiofrequency wire energy.

Modernization of the brake system of unwinding on rope machines

In order to reduce the cost of producing metal cord in the hardware shops of OJSC “BSW” – the Management Company of the Holding “BMC”, work is underway to modernize and select materials for replaceable technological equipment. In the process of twisting the metal cord on the unwinding of the power coils of rope machines, brake devices are used, consisting of a disk and sectors (pads) fixed in a chain. The elements of the unwinding unit are in constant contact, providing the necessary tension force for unwinding a thin wire. The performance of the braking devices affects the manufacturability of the twist, the absence of breaks, the density and geometric arrangement of the wires in the twisted metal cord that meets the requirements of consumers.Due to constant contact friction at high linear speeds, the brake pads wear out, which leads to emergency operation of the equipment. The article considers the test results of the modified thin wire unwinding unit and the impact of modernization on the service life of brake pads.

The unreliable mediator

Within the array of sounding devices that have been deployed in the making of sound art, the speaker has a special status. Although not ubiquitous, the extent of the speaker’s influence on sound art cannot be underestimated, and yet for many artists the speaker remains an obstinate, unyielding thing, acknowledged for its function but not embraced for its form. Sound art has frequently positioned itself within the discourse of contemporary sculpture and installation art and, as such, both the affordances of sound itself and the materials of its technical apparatus need to be understood as different dimensions of what constitutes its medium. This brief survey of the uses of speakers in sound art uses Lucier’s Music on a Long Thin Wire as a case study in which the speaker is utilized not just for its ability to convey sonic meaning generated elsewhere but also as a thing in its own right.

Proximity Sensor for Thin Wire Recognition and Manipulation

In robotic grasping and manipulation, the knowledge of a precise object pose represents a key issue. The point acquires even more importance when the objects and, then, the grasping areas become smaller. This is the case of Deformable Linear Object manipulation application where the robot shall autonomously work with thin wires which pose and shape estimation could become difficult given the limited object size and possible occlusion conditions. In such applications, a vision-based system could not be enough to obtain accurate pose and shape estimation. In this work the authors propose a Time-of-Flight pre-touch sensor, integrated with a previously designed tactile sensor, for an accurate estimation of thin wire pose and shape. The paper presents the design and the characterization of the proposed sensor. Moreover, a specific object scanning and shape detection algorithm is presented. Experimental results support the proposed methodology, showing good performance. Hardware design and software applications are freely accessible to the reader.

An efficient hybrid method for analyzing the coupling response of microstrip antenna system

This paper presents an efficient hybrid method consisting of Lorentz reciprocity theorem, finite-difference-time-domain (FDTD) method, thin wire model, transmission line (TL) equations and transfer impedance model, which can be utilized to analyze the system-level transient responses of the microstrip antenna system with antenna, metallic enclosures, braided shielded cable, and lumped element, when illuminated by an external electromagnetic pulse (EMP). In order to avoid over-fine mesh generation and repeated modeling of the antenna in multiple simulations, Lorentz reciprocity theorem is employed to extract an equivalent source model of antenna coupling, thereby improving the computational efficiency. Then, the transfer impedance model and thin wire model are incorporated into the FDTD-TL method efficiently to deal with the back-door coupling through the shielding layer of feeding coaxial cable. Finally, the hybrid FDTD method combined with the extracted equivalent source of antenna coupling is utilized to solve the coupling responses of the whole antenna system. The results of numerical simulation are verified by comparing with the simulation results of CST CS. Then, considering the influence of different incident conditions of external EMP, the characteristics of the coupling response of the system are analyzed. The obtained coupling response information demonstrate that the proposed method is available for further designing electromagnetic protection of the inner circuits of the microstrip antenna system against the impact of external EMP.