An optimized molar ratio of magnesia (MgO) and boric acid (H3BO3) was used to synthesize the nanorod of single-phase magnesium borate (Mg2B2O5) through a solution reaction cum sintering process. Due to their impressive mechanical strength and resistance to heat and corrosion, magnesium borates (MB) nanorods are extensively applicable as reinforcing materials. A meticulous examination was undertaken to assess the characterization and physico-mechanical properties of Mg2B2O5 (MB) nanorods during the sintering process between 700 degrees C and 1200 degrees C. Mechanical properties of synthesized MB compacts were investigated between 700 and 1200 degrees C. The maximum value of high temperature flexural strength (HMOR) and room temperature flexural strength (CMOR) achieved by MB compacts are 42 MPa and 53 MPa respectively. Furthermore, the compacts have a maximum compressive strength of 118 MPa and a maximum hardness of 64 HV at 1100 degrees C, making it promising reinforcing material for composites.

Automobile exhaust contributes the largest sources of carbon monoxide (CO) into the environment. To control this CO pollution, the catalytic converters have been discovered. The catalytic converters have been invented for regulating the CO discharge. There are many types of catalysts have been investigated for CO emission control purposes. Inorganic perovskite-type oxides are fascinating nanomaterials for wide applications in catalysis, fuel cells, and electrochemical sensing. Perovskites prepared in the nanoscale have recently received more attention due to their catalytic nature when used as electrode modifiers. Perovskite catalysts show great potential for CO oxidation catalyst in a catalytic converter for their low cost, high thermal stability and tailoring flexibility. It is active for CO oxidation at a lower temperature. The catalytic activity of these oxides is higher than that of many transition metals compounds and even some precious metal oxides. They represents attractive physical and chemical characteristics such as electronic conductivity, electrically active structure, the oxide ions mobility through the crystal lattice, variations on the content of the oxygen, thermal and chemical stability, and supermagnetic, photocatalytic, thermoelectric and dielectric properties. The surface sites and lattice oxygen species present in perovskite catalysts play an important role in chemical transformations. The partial replacement of cations A and B by different elements, which changes the atomic distance, causes unit cell disturbances, stabilizes various oxidation states or added cationic or anionic vacancies inside the lattice. The novel things disturb the solid reactivity by varying the reaction mechanism on the catalyst surface. Thus, the better cations replacement may represent more activity. There are lots of papers available to CO oxidation over perovskite catalysts but no review paper available in the literature that is represented to CO oxidation.

The catalytic conversion of carbon monoxide (CO) into carbon dioxide (CO2) at a low temperature is very important procedure for all living beings present in the environment. The present study represents that the addition of gold (Au) nano-particles, by the deposition-precipitation method into the hopcalite (CuMnOx) catalyst has been improving their performances for CO oxidation. The CuMnOx catalyst loading by 0.75 wt% Au was representing that the best catalytic activity for CO oxidation than the other catalysts loading by 0.25, 0.5 and 1 wt% Au. The small amount of Au doping (0.75 wt%) in CuMnOx catalyst improves their performances for CO oxidation at an ambient conditions. The gold nano-particles will be introducing the new active sites into the CuMnOx catalyst surfaces and decreases the deactivation of catalyst. The lattice oxygen movement was a major important factor which can influences the performances of hopcalite catalyst for CO oxidation. The calcinations strategies (reactive calcinations and traditional calcinations) of the precursor have huge impacts on the performances of resulting catalysts. The reusability of Au promoted CuMnOx catalyst was also measured and found that this catalyst does not have any major changes in its catalytic performances still after the reuses.

The increasing concentration of carbon monoxide (CO) present in the atmosphere showed worse health and environmental problems. Catalyze CO into CO2 believed as one efficient and promising techniques for eliminating this contaminant. The iron (Fe) nanoparticles catalysts have been widely investigated over the last few decades due to their unique properties, which is also a promising candidate for CO catalytic oxidation. The catalytic performances of Fe nanoparticles are highly relevant to the crystallite size and porosity of catalysts, so as to CO oxidation. Understanding the factors that affect CO oxidation on Fe nano-sized materials will help optimize the conditions for CO oxidation on specific nano-sized Fe catalysts. The recovery of Fe nanoparticle catalysts from the reaction system without loss of catalytic activity during CO oxidation have attracted certain attention. From the point of view of low cost, heat, activity and selectivity, Fe nanoparticle catalyst has been regarded as an excellent catalyst. This review will provide a scientific basis and references for the potential design of iron nanoparticle catalysts for CO oxidation.

Carbon monoxide (CO) is very poisonous gasses present in the atmosphere and lower temperature complete oxidation of CO is very important processes for all life support. The automobile vehicles exhaust is one of the major sources of CO produced into the environment. The application of catalytic converter in automobile vehicles reduces the toxic gasses emission. There are lots of catalysts used in the catalytic converter for CO oxidation purposes among these catalysts the Hopcalite (CuMnOx) is one of the oldest and best-known catalysts for low temperature CO oxidation. The hopcalite catalyst is prepared by the co-precipitation method and preparation parameters like magnetic shaker shaking speed, shaking time, shaking temperature and pH has an influence on the activity of resultant catalysts. The activity of catalyst was measured in reactive calcinations (RC) conditions at the presence of (1.5% CO) and air. The reaction temperature was increased from room temperature to higher temperature at which the total oxidation of CO was achieved. The characterizations of catalysts are done by several techniques like XRD, FTIR, BET and SEM-EDX. These results are interpreted in terms of structure the active catalyst. The reusability of CuMnOx catalyst was also tested and also found that this catalyst does not show any high level of significant change in its catalytic performances even after reuses.

The present study is aimed to develop a high strength porcelain insulating material from locally available low cost raw porcelain materials by reinforcement of TiO2 (0 to 10 in wt.%) as a substitute replacing ZrO2 in the base porcelain material composition. Base porcelain composition was prepared from the mixture of kaolin, ball clay, quartz, feldspar. Pellets were prepared by applying a constant pressure of 170 MPa using isostatic hydraulic press with holding for a period of 10 min. Different characterizations techniques such as; X-ray diffraction (XRD) and scanning electron microscopy (SEM) used to evaluate the structural and micro structural changes, respectively by increasing the concentration of TiO2 (0–10 wt.%) and decreasing ZrO2 (10–0 wt.%) concentration at the base composition of porcelain composition. The measurement of mechanical strength and physical behavior of TiO2 and ZrO2 were analyzed for all the samples prepared with different compositions at sintering temperature (1250 and 1350 °C) with soaking period of 2 h. The base porcelain composition with 5 wt.% TiO2-doped concentration yields the better physical and mechanical strength. The investigated TiO2 based porcelain material using in refractory and high-temperature insulating applications where severe thermal shock with high mechanical features are required.

Hopcalite (CuMnOx) is one of the best catalysts for carbon monoxide (CO) oxidation at ambient conditions. In present research work we measured the performances of various precipitants (KMnO 4, Na2CO3 and KOH) used in the CuMnOx catalysts synthesis by the co-precipitation method and calcined at 300°C temperature. The KMnO 4 precipitant used in CuMnOx catalyst has shown that the best catalytic activity, which completely oxidized CO at the lower temperature (T100= 83°C). The other precipitants used in CuMnOx catalyst synthesis by Na2CO3 as precipitant for CO oxidation was done at (T100=105°C) and KOH used as precipitant in CuMnOx catalyst, which completely oxidized CO (T100=115°C). The calcinations conditions of precursors have huge impact on the performances of resulting catalysts for CO oxidation. The reactive calcinations (RC) conditions (1.5% CO in air) prepared CuMnOx catalysts have shown that the best catalytic activity as compared to the tradition calcinations conditions. The RC route is one of the best calcinations strategies for preparation of highly active CuMnOxcatalyst for CO oxidation.

In this article, the doping effect of BaTiO3 (0-2 wt%) on the physical, electro-mechanical and dielectric strength of prepared porcelain insulator were investigated. Green powder samples were sintered at 1350 degrees C with 2 h soaking time, applying uniaxial pressure techniques with a constant load of 160 MPa. The surface, morphological, elemental and phase analysis characterization was done by using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS) and X-ray diffraction (XRD) to recognize the microstructure-surface property relationship of the insulator. Various characterization like physical, electro-mechanical and alternating current (AC) dielectric strength of prepared sintered porcelain composition at 1350 degrees C were investigated. AC dielectric behavior, conductivity, and resistivity were measured at frequencies ranging from 20 Hz to 1 MHz. AC Dielectric constant and loss value from 2 GHz to 20 GHz with frequency and temperature variation were measured. The highest recorded value of AC dielectric strength for a sample having BT (2 wt%) is 25.75 +/- 0.5 kV/mm. The investigated composition having 0.5 wt% showed excellent electro-mechanical and high voltage dielectric strength as compared to the conventional porcelain insulators.

The low-temperature catalytic oxidation of carbon monoxide (CO) is very important process for all human health protection systems. The major sources of CO produced into the environment are automobile exhaust, so that the various types of catalysts are used in the catalytic converter for oxidation of CO. As compared to noble metal oxide catalysts the transitional metal oxide catalysts are very active, lower cost, easily available and fast regenerated. Among the various transitional metal oxide catalysts the nickel oxide (NiO) is one of the best catalysts for CO oxidation at a lower temperature. A small amount of NiO was deposited on mesoporous Al2O3 using atomic layer deposition and subsequently oxidation at different temperatures. Furthermore, as the pre-annealing temperature increased and improved resistance towards poisoning due to the CO oxidation was observed. The Ni/TiO2 catalyst show that the best efficiency in selectivity, performances and stability in the heterogeneous catalysis. The performances of NiO nanoparticles are highly dependent on the crystallite size, surface area and pore volume of the catalysts. The certain attention has been paid on recovery of Ni nanoparticle catalysts from reaction systems and their reuse for several times without losses of catalytic activity in CO oxidation. This investigation will shown scientific basis for potential design of Ni nano-particle catalysts for CO oxidation.

Carbon monoxide (CO) is one of the very poisonous gases present in the atmosphere and low temperature complete oxidation CO is very important process for all human being present in the environment. A catalytic converter was an emission control device that converts more toxic gases present in the automobile exhaust into less toxic gases by the catalytic reactions. The manganese oxide catalysts i.e. (XMn2Ox, X = Ce, Co, Fe, Cu) are prepared into laboratory by the co-precipitation method followed by calcinations in reactive CO–air mixture and traditional calcinations conditions. The activity order of catalysts for CO oxidation is as follows: CuMn2O2 > CeMn2O2 > CoMn2O2 > FeMn2O2. Among all the prepared catalysts, the CuMn2O2 has showed that the best catalytic activity for CO oxidation at the low temperature. The complete oxidation of CO was achieved at 85 ºC over CuMn2RCcatalyst. The calcinations strategies of precursors have great influenced on the activity of resulting catalysts. The CO oxidation activity was recognized to be a combination of factors including high surface area, active surface oxygen species and Mn(IV) cations. These results provide a novel thought to design the highly active CuMn2O2 catalyst.

The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker (ABOw) (5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventional powder metallurgy technique. The aluminium powder and the whisker were effectively blended by a semi-powder metallurgy method. The blended powder mixtures were cold compacted and sintered at 600 °C. The sintered composites were characterized for microstructural features by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. Porosity in the composites with variation in ABOw contents was determined. The effect of variation in content of ABOw on mechanical properties, viz. hardness, bending strength and compressive strength of the composites was evaluated. The dry sliding wear behaviour was evaluated at varying sliding distance at constant loads. Maximum flexural strength of 172 MPa and compressive strength of 324 MPa with improved hardness around HV 40.2 are obtained in composite with 10 wt.% ABOw. Further increase in ABOw content deteriorates the properties. A substantial increase in wear resistance is also observed with 10 wt.% ABOw. The excellent combination of mechanical properties of Al−10wt.%ABOw composites is attributed to good interfacial bonds, less porosity and uniformity in the microstructure.

Carbon monoxide (CO) is one of the very poisonous gasses and major sources of CO produced into the environment by the automobile vehicles exhaust. There are various types of catalysts have been used in the catalytic converter for CO oxidation. The titanium dioxide (TiO2) is one of the best transitional metal oxides catalysts for lower temperature CO oxidation. A small amount of TiO2 was deposited on the mesoporous Al2O3 using atomic layer deposition and subsequent oxidation at the different temperatures. The lightly reduced support improves the high catalytic activity of the adparticles, a strongly reduced one quenches the CO oxidation. The quenching is due to thermally activated diffusion of Ti3+ interstitials from the bulk to the surface where they deplete the oxygen adsorbed onto the clusters by the formation of TiOx (x ​≃ ​2) structures. The additions of promoters and support in titanium oxide catalysts improved their performances and reduced their stability. The bulk reduction state of TiO2 strongly affects the catalytic activity of supported metal clusters in the chemical reactions between oxygen and other molecules. The certain attention has been paid on the recovery of TiO2 catalysts from reaction systems and their reuse for various times without losses of catalytic activity in CO oxidation. This investigation will shown scientific basis for potential design of Ti-oxide nano-particle catalysts for lower temperature CO oxidation.

In the present study, bioactive glasses of specific compositional formula (45-X) SiO2, 24.5 Na2O, 24.5 CaO, and 6 P2O5 (wt%) were made by substitute of X = (0.0, 0.5, 1.0, 1.5, and 2.0) equal wt% of CeO2 and La2O3. The mixed homogeneous glass powder melted in a platinum crucible at the furnace temperature of 1400 ± 5 °C with air as a furnace environment. Synthesized novel Bioglass® was further characterized for in vitro bioactivity and physicomechanical properties. Microstructures of developed glass samples were evaluated by SEM. Bioactivity of glass samples was assessed in simulated body fluid (SBF) for different time intervals and it was evaluated using XRD, FTIR, and SEM. Furthermore, the substitution of CeO2 and La2O3 in the base glass enhances its cytocompatibility and cell supportive properties. Also, microhardness and flexural strength of base Bioglass® was enhanced with the incorporation of CeO2 and La2O3 and resulted in increasing density of doped glass. Thus, the developed CeO2 and La2O3-incorporated bioactive glasses with superior mechanical properties have higher density and superior mechanical properties which make these bioactive glasses a suitable candidate for bone implant application.

The emissions of pollutants from vehicles are generally low but the numbers of vehicles increasing on the road therefore the environmental pollutions are also increases. About 35% of CO, 30% of HC and 25% percent of NOx produced into the atmosphere is from the transportation sector. These pollutants have adverse effects on the environment and human health. The emissions from vehicles are generally depends upon the air–fuel ratio. The control techniques for exhaust gas emissions are engine modifications, fuel pretreatment, fuel additives, exhaust gas recirculation (EGR), positive crankcase ventilation (PCV) and an application of catalytic converters. A catalytic converter is a device that converts more toxic exhaust gas pollutants into less toxic pollutants. There are different types of catalysts used in the automobile exhaust gas treatment like noble metal and base metals catalysts etc. The catalytic converter was effective and consistent for reducing the noxious tailpipe emissions so that it was developed for use in the trucks, buses, cars, motorcycles and other construction equipped. This paper will discuss about the different types of recent developments in catalysis for automobile exhaust pollution control.

The technological demand for polymer thin film transistors (PTFTs) is continuously increasing because of their potential applications in various kinds of sensor designs. Despite this, there is need for development of a facile technique that can produce high performance low cost PTFTs. Therefore, a facile method is presented for ultrafast formation of large area self-assembled, highly orientated, crystalline polymer thin films at high surface free energy mobile air-liquid interface named "floated polymer thin film over fluid substrate." The grown thin film over different solid substrates is studied by multiple-characterization techniques viz. high resolution-transmission electron microscopy, grazing incident X-ray diffraction, absorption spectroscopy, and cyclic voltammetry. Finally, the PTFTs having bottom gate and top contact configuration with the variations in source-drain (S/D) electrode is fabricated for ammonia sensing. A synergistic enhanced ammonia vapor sensing performance with dual sensing characteristics through Pd-electrode based PTFTs is observed when it is operated in two different modes of operation, that is, ON state to OFF state and vice-versa. However, this transition is absent in Au-electrode based PTFTs. Further, the observation of high gas response and dual sensing phenomena for ammonia vapor is argued by the evidence from a higher (approximately threefold) mobility, scanning electron microscopy (SEM), and atomic force microscopy (AFM) images.

Increasing approachability of substitute materials for electrical ceramic porcelain insulator, research is requisite to adapt designs including porcelain raw materials to the current economic realities of the industry. This study aimed to analyze the effect of zirconia concentration (0, 2.5, 5, 7.5, and 10 wt.%) on the physical, mechanical, and dielectric properties of an alumina-based ceramic insulator. The pellets were prepared using the uniaxial pressure technique applying 160 MPa pressure. Different characterizations techniques such as XRD, dilatometer, and SEM used to identify the phase, thermal, and microstructural changes, respectively, of the sintered samples (1350 °C). Results indicated that alumina-based porcelain composition with 7.5 wt.% zirconia shows the maximum density of 2.63 g/cm3 with minimum water absorption of 0.18%. The average measured value of the coefficient of thermal expansion (αavg) for each sintered samples from 250 to 450 °C, and 1050 to 1250 °C is 8.254 × 10−6/ °C, and 7.16 × 10−6/ °C were observed, respectively. The highest bending (141 ± 5 MPa), compressive (216 ± 10), and tensile (40 ± 3 MPa) strength were also noted for the same composition. The value of dielectric, resistivity, and conductivity were also measured. From the result, it was concluded that low-cost raw materials with 7.5 wt.% zirconia-doped concentration yield the better physical, mechanical, and electrical properties with alumina-based electrical porcelain insulator.

The high-strength electrical porcelain insulator plays a vital role in the power industry. The present study investigates the effect of alumina and silica addition on the physico-mechanical and electrical properties of porcelain bodies over high sintering temperatures. The pallets were prepared in different shapes and dimensions with the help of hydraulic press machine by pressing at 160 MPa for a period of 10-min. Different characterizations techniques such as; dilatometer, X-ray diffraction (XRD), and scanning electron microscopy (SEM) used to evaluate the thermal, structural, and microstructural changes, respectively by increasing the concentration of silica (0-20 wt.%) and decreasing alumina (45-25 wt.%) concentration for the base composition of porcelain insulator. The measurement of mechanical strength and physical behavior were analyzed for all the samples prepared with different compositions of alumina and silica with varying sintering temperature (1250 and 1350 degrees C). The sample with a composition having silica 10 wt.% of alumina 35 wt.% and sintered at 1350 degrees C, shows the maximum density of 2.55 g/cc with water absorption of 0.94%. This sample also shows the highest value of bending and compressive strength of 129 +/- 5 and 202 +/- 5 MPa respectively. The highest dielectric value of 5.75 and minimum dielectric loss of 0.05 at a frequency (2-20 GHz) is achieved for the same composition with silica 10 wt.% of alumina 35 wt.% sintered at 1350 degrees C. The composition having silica 10 wt.% with alumina 35 wt.% sintered at 1350 degrees C, has enormous potential to serve as a high strength refractory and a dielectric ceramic material for microwave applications. (C) 2017 SECV. Published by Elsevier Espana, S.L.U.

In this article, the effects of sintering on the mechanical and electrical properties of ceramic porcelain insulator reinforced by zirconia (ZrO2) particles are studied for the low frequencies (20 Hz–1 MHz). The samples were prepared for varying contents of zirconia by replacing alumina content in the base porcelain composition. The samples are sintered at 1250 °C and 1350 °C with a heating rate of 5 °C min−1 and the soaking period is 2 h. The β-cristobalite phase of base porcelain decreases and the crystalline phase of zircon increases with the increasing sintering temperature. This improvement in crystallite phase of zircon improves the mechanical strength of the reported samples. The sample with zirconia content of 20 wt% sintered at 1350 °C shows the best mechanical properties with minimum water absorption of 0.89%. The highest measured value for modulus of rupture (MOR), compressive strength, and linear shrinkage are 138 ± 5 MPa, 221 ± 10 MPa, and 10.6%, respectively. The sample with zirconia content of 30 wt% sintered at 1350 °C shows the best electrical properties among all samples. Maximum observed value for AC dielectric strength of the sintered sample is 22.85 ± 0.5 KV mm−1. The measured AC conductivities of samples are 3.88 × 10−12 S cm−1 and 1.41 × 10−9 S cm−1 at 500 Hz and 1 MHz respectively. The complex permittivity’s of the sintered samples are found to be dependent on contents of ZrO2 and also exhibit a frequency dependent characteristics for a range of frequency (20 Hz to 1 MHz). The result indicates that variation in ZrO2 composition leads to significant improvements in mechanical and electrical properties of porcelain ceramic.

In the present study, the effect of ZrO2 on the sintering, strength and dielectric behavior of electrical ceramic porcelain insulator with substituting alumina content by zirconia (in weight percentage from 0% to 30%) is investigated. The different composition of samples containing different zirconia (ZrO2) contents of 0, 10, 20, and 30 wt% are prepared using the uniaxial pressure technique applying 160 MPa pressure. Further, the prepared samples are also analyzed for sintering temperatures (1350 degrees C), and effects are observed on mechanical and electric properties of porcelain insulator. Different characterizations such as Dilatometer, x-ray diffraction, scanning electron microscopy and differential thermal analysis/thermo gravimetric analysis were used to evaluate the thermal, phase detection, micro structural and weight loss changes by increasing concentration of ZrO2 on base porcelain composition. At 1350 degrees C, for the composition having 20 wt% ZrO2 with 10 wt% alumina, the maximum density was observed 2.81 g cm(-3) with a porosity of 2.23%. The highest tensile strength of 41 +/- 3 MPa is observed for the same sample composition. The minimum value of thermal expansion coefficient is found to be in the range of 10(-6) for the sample with 30 wt% ZrO2 content sintered at 1350 degrees C compared to other prepared samples. Similarly, the highest dielectric value (5.1-4.4) having dielectric loss (0.08-0.12) is achieved for the sample with 30 wt% ZrO2 content sintered at 1350 degrees C in the frequency range of 4-20 GHz at room temperature. According to the mechanical properties, the composition having 20 wt% ZrO2 on base ceramic porcelain composition has enormous potential to serve as a high strength refractory material. For dielectric properties, the composition having 30 wt% ZrO2 is more suitable for the electrical application.