2021 F.N. Speller Award Lecture: CORROSION MECHANISMS OF STEEL AND COPPER IN ENGINEERING APPLICATIONS

The main research lines of the scientific career of the author are herein, exemplified including corrosion and protection mechanisms of steel in different environments, and copper corrosion in climate systems. Stainless steel (SS) due to its high corrosion resistance is a material widely used for many engineering applications. Impedance measurements were performed on polarized at the pitting region AISI 304 SS in environment containing chloride at 25 and 60 ºC. The transfer function was analyzed indicating instability system, corroborating results obtained using the Kramers-Kronig transforms. Steel reinforcement has been studied for structural applications in civil engineering and architecture using cementitious materials, alkaline activated fly ash (AAFA), alternative to the ordinary Portland cement (OPC). The main compounds used as corrosion inhibitors in concrete were included. Carbon steel embedded in OPC mortar was tested in the presence of phosphates as corrosion inhibitors. An organic lacquer was applied to tinplate with titanium-passivation treatment and, in general, acceptable and comparable behavior was obtained to conventional chromium-passivated lacquered tinplate. Copper is also a material used in many engineering applications. Ant-nest corrosion of copper tubing in air-conditioning systems has been reported. The copper corrosion rate occasioned by carboxylic acids, formic, acetic, propionic and butyric, was included.

Optimization design and operating parameters of induction heat-ing system for hardening

The paper deals with the problem of optimizing the design and operating parameters of an induction heating system for surface hardening of a steel stepped shaft. The problem of optimal design of an inductor is formulated based on a nonlinear two-dimensional numerical model of coupled electromagnetic and temperature fields, developed in the ANSYS Mechanical APDL software. Alternance method of parametric optimization of systems with distributed parameters is used to optimize induction hardening system. MATLAB software has been used for developing parametric optimization subroutine, which was incorporated into the numerical ANSYS model to simulate a process of induction heating. Commonly used a multi-turn solenoid-style coil fabricated from rectangular copper tubing has been used as a hardening inductor. Besides that, an application of profiled copper turns has been investigated. Optimization of induction hardening system described above allows one to substantially improve heating uniformity and enhance metallurgical characteristics of as-hardened stepped shaft. Localized temperature surplus at an upper diameter shoulder has been minimized. At the same time, sufficient austenitization in the fillet area near stepped region (diameter transition) has been obtained.

Theoretical Efficiency and Practicality of the Solar Trough Collector / Tikrit-Iraq

An experimental and theoretical study was conducted to attain solar collectors’ thermal efficiency. Testing was done during May of 2019 on a solar collector’s surface at the Physics Department of the University of Tikrit. The absorbent tubes used had a length of 1.5 m, were painted black, made of copper, had an outer diameter of 0.03 m, internal diameter of 0.028 m, and a tank capacity of 40L. By entering these specifications along with those of the solar collector, the theoretical thermal efficiency was calculated. The findings showed that practical efficiency curves and useful thermal energy absorbed by the water contained goes down when using copper tubing. The results also illustrated that useful thermal energy and thermal efficiency increases along with increasing the mass flow rate of water.

CREATION OF A LOW-COST ENDOSCOPIC FLAVECTOMY TRAINING MODEL

ABSTRACT Objective The objective of the study was the development of a low cost simulator of the endoscopic lumbar spine flavectomy technique for use as a teaching method in order to make endoscopic training more accessible. Methods The study was a descriptive research project conducted at the Orthopedic Skills Laboratory of the Health Sciences Department of the Federal University of Paraná. Easily accessible, low cost materials, such as a commercial-use mannequin, EVA plastic, PVC and copper tubing were used to develop the simulator.. Results At the end of the project, it was possible to build a simulator of the endoscopic lumbar spine flavectomy technique with a budget of approximately 464 BRL, or approximately 140 USD. Conclusions We concluded that it was possible to build an endoscopic lumbar spine flavectomy technique simulator on a budget of less than half a Brazilian minimum monthly wage, which makes training more accessible to academics, residents and surgeons. Level of Evidence V; Expert opinion.

Continuous Flow Chlorination of Alkenyl Iodides Promoted by Copper Tubing

A simple continuous flow synthesis of alkenyl chlorides from the corresponding readily available alkenyl iodides in copper reactor tubing is described. A variety of alkenyl chlorides were obtained in good to excellent yields with full retention of the double bond geometry. The reaction time was reduced by a factor of 24–48 compared to the batch process.