Isothermal transformation characteristics of a medium carbon Ti-V microalloyed steel were

investigated using light microscopy, scanning electron microscopy (SEM) equipped with energy

dispersive spectroscopy (EDS), and by uniaxial compressive testing. Samples austenitized on 1100 C

were isothermally treated in the range from 350 to 600 C and subsequently water quenched. The

final microstructure of the samples held at 350 C consisted of bainitic sheaves and had compressive

yield strength, approximately from 1000 MPa, which is attributed to high dislocation density of

low bainite. At 400 and 450 C, acicular ferrite became prevalent in the microstructure. It was also

formed by a displacive mechanism, but the dislocation density was lower, leading to a decrease of

compressive yield strength to approximately 700 MPa. The microstructure after the heat treatment at

500 C consisted of coarse non-polygonal ferrite grains separated by pearlite colonies, principally

dislocation free grains, so that the compressive YS reached a minimum value of about 700 MPa. The

microstructure of the samples heat-treated at 550 and 600 C consisted of pearlite and both grain

boundary and intragranular ferrite, alongside with some martensite. After 600 s, austenite became

stable and transformed to martensite after water quenching. Therefore, the presence of martensite

increased the compressive YS to approx. 800 MPa.

The aim of this modest study was to shed some light on one of

the useful tools of complex analysis, which is the method of conformal

mapping (Also called conformal transformation). Conformal

transformations are optimal for solving various physical and

engineering problems that are difficult to solve in their original form

and in the given domain. This work starts by introducing the meaning

of a ''Conformal Mapping'', then introducing its basic Properties. In the

second part, it deals with a set of various examples that explain the

behavior of these mappings and show how they map a given domain

from its original form into a simpler one. Some of these examples

mentioned in this study showed that conformal transformations could

be used to determine harmonic functions, that is, to solve Laplace's

equation in two dimensions, which is the equation that governs a variety

of physical phenomena such as the steady-state temperature distribution

in solids, electrostatics and inviscid and irrotational flow (potential

flow). Other mathematical problems are treated. All problems that are

dealt with in this work became easier to solve after using this technique.

In addition, they showed that the harmonicity of a function is preserved

under conformal maps and the forms of the boundary conditions change

accordingly

Contamination of wastewater by toxic metals is a global environmental concern. In this study, the possibility of using inactive (dead) Sargassum bacilluria powder as a natural adsorbent was investigated in the removal of cadmium from aqueous solutions. The biosorption process was found to be highly dependent on a set of variables such as pH, temperature, contact time, shaking speed and initial metal concentration. The results showed an optimum pH value, (6.0) for cadmium, where was the biosorption capacity (842.15±0.252) for cadmium, and the lowest biosorption value for Cd was found at pH 2.0. The optimum temperature in this study was 30 °C. The time required for equilibrium was investigated over a period of 360 min and found to be 180 min. The capacity of biosorption increased with increasing shaking speed, and the highest uptake value was found at 120 rpm. The maximum removal of Cd+2 was found at 20 mg/l. The models Freundlich and Langmuir were used to study the equilibrium process of these systems. The Langmuir model was found to be more suitable for the interpretation of these systems by the value of the correlation coefficients higher than 0.99. Brown seaweed powder is an effective, low-cost, .and environmentally friendly adsorbent for removing metals from aqueous solutions, according to the results obtained.