Current Materials Science - Current Issue

Ceria (CeO2) belongs to rare-earth series and due to its profitable properties, presents a wide commercial use such as catalysis, energy, biological, biomedical, and pharmaceutical. The features of the starting materials in the form of free powders influence notably the processing, formation, as well as characteristics of the final structures\bodies obtained by colloidal processing. This study aims to characterize CeO2 powders. The results obtained are worthwhile data to advance toward new rare-earth based materials for radiation dosimetry.

CeO2 powders were evaluated by the following techniques: PCS, SEM, XRD, FT-IR, EPR, IPC, and pycnometric density (ρ). The stability of particles in aqueous solvent was evaluated by zeta potential (ζ) determination.

CeO2 powders exhibited cubic C-type form, Fm-3m space group, a mean particle size (d50) of 19.3 nm, and a pycnometric density (ρ) of 7.01g.cm^-3. Based on the results of zeta potential determination, CeO2 powders exhibited high stability at pH 6.4 with ζ-value of |34.0|mV.

The evaluation of CeO2 powders was reported. The results presented and discussed in this study contribute to advance in the search of new rare-earth based materials for radiation dosimetry.

Our country has dramatically evolved over the decades, and now we have a large number of well-connected roads, public buildings and a rising number of automobiles. With the passage of time, the manual car parking system in commercial spaces has become a stumbling block and wastes time. As a result, it requires a solution that can address these issues. Automated car parking systems are the answer to these issues.

In this study, the static and dynamic response spectrum approach was used to analyze G+13 storey automated car parking by using ETABS-2018 systems

The storey displacement, storey stiffness, storey shear and overturning moment of steel and Reinforced cement concrete (RCC) automated car parking tower subjected to static and dynamic load for seismic zone III and zone IV in India have been determined.

The RCC automated car parking tower was found to be not only stiffer but also lowered the displacement of construction.

In this research work, an attempt was made to machine Ti6Al4V nano composites utilizing Al2O3 mixed nano fluid at minimum quantity lubrication condition, in which experiments were designed using the L16 orthogonal array, whereas Material Removal Rate, Surface Roughness, machining force and power were recorded as responses.

The nano composites were fabricated using the stir casting technique and the nano particles were synthesized using the sol-gel technique. the microstructure revealed that the homogeneous dispersion of particles with dendric arms. Increased cutting speed and feed lead to more tool wear, which in turn causes a decrease in surface quality and an increase in surface roughness.

Larger areas of cut are often the consequence of higher feed rates, which increases the amount of friction between the work piece and the cutting edge. The machining force increases when the feed rate is increased. A higher feed rate produces a large volume of the cut material in a given length of time in addition to having a dynamic impact on the cutting forces.

It also results in a corresponding increase in the typical contact stress at the tool chip interface and in the tool chip contact zone.

In this paper, we aimed to prepare SiC-CDC with porous structure from SiC precursor by using simple molten salt electrochemical etching method at 900 ºC in argon at an applied constant voltage of 3.0 V.

Nanoporous materials include carbon materials, silica or alumina, gel, and zeolite, which have been known since ancient times. Among all these materials, carbon materials are particularly outstanding. In recent years, carbide-derived carbon (CDC), a type of unconventional carbon material produced by selectively extracting metal elements from the lattice of carbides, has attracted increasing attention from researchers. Many different methods have now been proposed to prepare CDC, among these methods, currently the preparation of mesoporous carbide-derived carbon (CDCs) materials mainly relies on chlorination. The main problems with chlorination are the corrosion of chlorine gas and the treatment of secondary products (MClx). Therefore, the search for environmentally friendly strategies for the production of CDC is still ongoing.

This article proves that we can successfully prepare SiC-CDC with porous structure from SiC precursor by using simple molten salt electrochemical etching method at 900ºC in argon at an applied constant voltage of 3.0 V.

The SiC-CDC with porous structure has been prepared from SiC precursor by using simple molten salt electrochemical etching method at 900ºC in argon at an applied constant voltage of 3.0 V.

The results show that the nanoporous SiC-CDC was successfully synthesized from the silicon carbide microspheres powder via by electrolysis in molten CaCl2 at 3.0 V, 900°C for 15 h.

The nanoporous SiC-CDC was successfully synthesized from the silicon carbide microspheres powder via by electrolysis in molten CaCl2 at 3.0 V, 900°C for 15 h and their microstructure, specifc surface area, and pore size were analyzed. The SiC-CDC obtained in this experiment mainly consisted of amorphous carbon and maintained the shape of SiC particles. The SiC-CDC is a mixture of amorphous carbon and ordered graphite phase with a highly degree of graphitization. The SiC-CDC displays a BET specific surface area of 561.39 m²/g and a total pore volume of 0.39 cm³/g. This method to produce SiC-CDC is very attractive because it will not only pave a new way for the preparation of SiC-CDC but also for mass production of high-quality carbon material.

In the current context of low-carbon environment, it is particularly important to use waste plastics to prepare modifiers that increase the modulus of the bituminous mixture.

The study aimed to find out the influence of environment-friendly polymer composite modifier (E-FPCM) on modulus and pavement performance of bituminous mixture.

The influence of the optimum component E-FPCM on the dynamic modulus (DM) has been explored. The E-FPCM content’s effect on the rheological properties of bitumen has been analyzed. Also, the influence of E-FPCM on pavement performance has been analyzed.

The degree of influence on SR of bituminous mixture has been in the order of recycled low-density polyethene (R-LDPE) > aromatic oil > lignin fiber. The optimum composition of E-FPCM has been found to be 10% aromatic oil, 4.8% C9, 62% R-LDPE, 7.0% lignin fiber, 0.2% antioxidant 1076, 2% silane coupling agent, and 14% mineral powder. By using E-FPCM with the optimum components, the SBS bituminous mixture or 90^# bituminous mixture has been found to meet the standard of a high-modulus bituminous mixture (HMBM). E-FPCM has been found to reduce the phase angle (δ) of bitumen and increase the complex shear modulus (G*) and rutting factor [G*/sin(δ)], which may help improve the rutting resistance (RR).

E-FPCM is beneficial for improving the RR of the bituminous mixture, and reasonable content of E-FPCM has a great role in improving the water stability (WS) and low-temperature crack resistance (LTCR) of the bituminous mixture.

This work represents the influence of gate dielectric, and the nano-cavity gap of a dielectric modulated trench gate Junction-less Double Gate Field Effect Transistor (JL-DGFET) on the different performance indicators is investigated considering the Low-Frequency Noise.

It is noted that the gate dielectric and the nanogap, both parameters, have a substantial influence on the sensing capacity and performance of noise of the device.

A double gate suitable dielectric material and cavity thickness can effectively improve the biosensor’s sensitivity with a minimum amount of noise.

The sensitivity is found to increase up to 9.5 for dielectric constant, k = 3.57 and 6.5 for dielectric constant, k = 2.1.

A steel frame system becomes structurally less efficient when subjected to large lateral loads such as a strong wind or a severe earthquake. Several techniques could enhance the structural performance against these lateral loads, including single diagonal and X-bracing systems, moment-resisting frames, and viscous dampers.

This study aimed to compare these techniques' ability to reduce the structure's dynamic and static behavior when it faces lateral loads. The structure dynamic behavior was discussed through its lateral displacement response computed from the nonlinear dynamic analyses using different seismic and harmonic excitations. The structure static behavior was investigated based on the demand capacity curves and the plastic hinges response computed from the nonlinear static analyses (Pushover) following FEMA P-1050-1 guidelines. In this paper, the viscous dampers were assumed to have a nonlinear behavior (0<α<1) and the impact of the velocity exponent α on their performance against the dynamic excitations was evaluated.

The results show that the X-braced frame performs better in reducing the structure displacement response and plastic hinges performance levels formed in the structural members than a single diagonal braced frame, followed by a moment-resisting frame. The results also indicate that the X-braced frame has a larger base shear resistance capacity and a smaller deformation capacity than other structural configurations.

It was also concluded that, for the same damping coefficient, the performance of nonlinear viscous dampers increased as the velocity exponent decreased.

The spindle top is an important component used to withstand the shaft workpiece on machine tools so that the spindle can meet high efficiency and high precision requirements. However, the selection principles under various load conditions are not stipulated in use. In addition, material selection, manufacturing, heat treatment technology, etc., are of practical significance for the production of high hardness, high wear resistance, and high precision spindle tops.

The spindle top type, material selection principles, heat treatment, cold working, and other manufacturing processes are given. Provide a reference for high-performance and top-notch design and manufacturing.

The model of the spindle top will be created in UG software, then using ANSYS finite element analysis software to analyze stiffness of spindle top whose height-to-diameter ratios are 1:4 and 1:7 types in a variety of different load cases. The design and manufacturing process of the spindle top is analyzed and expounded from the selection and performance comparison of metal materials, heat treatment of different materials, cold manufacturing technology, and other aspects.

The deformation laws of different types of spindle tops are obtained. According to the deformation regular, find the selection principle of height to diameter ratio of spindle top. The defects that are easy to occur in the technology are obtained and the preventive and solution measures are put forward.

According to the deformation regular, find the selection principle of height to diameter ratio of spindle top. The material selection, heat treatment technology, and other technical research on the spindle top provide the necessary basis for the production of the spindle top.