Thermomechanical Analysis of (Cu_(0.5)Tl_(0.5))-1223 Substituted by Pr and La

The thermomechanical analysis （TMA） of Cu0.5T10.5Ba2Ca2-xRxCu30110-δ, where R=Pr and La, with 0.0〈x〈0.15, was carried out in temperature range from 450 to 1145 K. The samples were prepared by singlestep solid state reaction technique. The prepared samples were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The superconductivity of the prepared samples was investigated by electrical resistivity measurement. The results showed that low substitution content enhanced the （Cu0.5Tlo.5）- 1223 phase formation, while the higher substitution content degraded this phase. The higher superconducting transition temperatures Tc were found to be 114 K and 109 K at x= 0.025 for Pr- and La-substitutions, respectively. The average linear thermal expansion coefficient increased as x increased, while the shrinkage temperature decreased as x increased. Those results were emphasized by porosity and Vickers microhardness calculations. Debye temperature 0D was calculated from the linear thermal expansion coefficient data and correlated to Tc to estimate the electron-phonon coupling λep.

Thermo-Mechanical Analysis of a Typical Vehicle Engine Using PTC-Creo

In this work,a typical vehicle engine is modeled within PTC-Creo soft­ware,and its thermal,mechanical,and thermo-mechanical performance are evaluated.This is followed by the vibrational,fatigue,and buckling analy­sis of the assembly of components,which are the predominant failure caus­es.The results show that the least temperature gradient occurs in the center of the pin,which connects the piston to the connecting rod,the maximum displacement is seen just below the piston head,and the thermo-mechanical failure is caused mostly(about 85%)by the mechanical load rather than the thermal one.Also,in fatigue analysis,the minimum and maximum values for the safety factor are 0.63 and 5,respectively.The results can prevent the reoccurrence of similar failures and help the enhancement of the compo­nents’design and manufacturing process.

Comparing the Behavior of Reinforced Concrete Columns Embedded in Walls and Subjected to Fire

Fire is an exceptional action that may occur during the life of a building.So,it must be considered when designing a building structure.The standards provide several types of design methods for that propose,used for single elements,parts of structure or the structure as a whole.The fire design of columns is important both for new project as for remodel buildings and also for verification of the residual resistance of columns that have suffered a fire accident.In this way,the aim of this work is to analyze numerically different ways of fire exposure to check the compressive strength of the columns when subjected to fire and the influence of the adjacent walls to a column in case of fire.The thermal advanced analysis of the sections columns was performed using the finite element software,Abaqus CAE,where the standard fire curve,ISO 834(International Organization for Standardization 834),was used,with 4 h of fire duration.It was possible,with the two methods used in this work,to compare them to verify which model is more conservative and which is closer to the advanced numerical model,for calculating temperatures in the column section.It was checked that the walls act as thermal insulators,protecting part of the columns from the convection and radiation of the fire.Consequently,the effects of raising the temperature over the compressive resistance of the reinforced concrete column,were reduced.

Distribution behavior of valuable elements in oxygen-enriched top-blown smelting process of waste printed circuit boards

Oxygen-enriched top-blown smelting is a promising technology for processing waste printed circuit boards(WPCBs).The distribution behavior of valuable elements in WPCBs during smelting was investigated by varying the oxygen-enriched concentration,oxygen volume,CaO/SiO_(2)(mass ratio),and Fe/SiO_(2)(mass ratio).The optimal operating conditions were obtained by implementing a one-factor-at-a-time method.X-ray diffractometer,scanning electron microscopy−energy dispersive spectrometer,and inductive coupled plasma-atomic emission spectroscopy methods were utilized to detect the chemical composition,occurrence state as well as elemental contents of alloy and slag.It is found that the elements of Cu,Sn and Ni are mainly accumulated in the alloy while Fe is mainly oxidized into the slag.The direct yields of Cu,Sn and Ni are 90.18%,85.32%and 81.10%under the optimal conditions of temperature 1250℃,oxygen-enriched concentration 30%,oxygen volume 24 L,CaO/SiO_(2) mass ratio 0.55,and Fe/SiO_(2) mass ratio 1.05.The results show that the valuable metals are mainly lost in the slag through mechanical entrainment.