Influence of Annealing Methods on the Morphological and Optical Properties of Cu2O Nanoparticles Prepared by Chemical Bath Deposition

In this work, the cuprous oxide (Cu2O) thin film on glass substrates were fabricated at low growth temperature by a single-step aqueous solution of chemical bath deposition method. In order to optimize optical and morphology quality, the effect of two different heat treatment methods are conventional furnace annealing process and continuous wave (CW) CO2 laser annealing technique were investigated. The effect of annealing temperatures on the properties of Cu2O thin films were systematically investigated by UV-Vis spectrophotometer, X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

A Numerical Study on the Energy Performance of a Novel Furnace With Acidic Gas Trap Absorbers

Natural gas furnaces are widely used in US residential and commercial building markets. An important issue for natural gas furnaces is serious corrosion and fouling problems caused by acidic gas, such as SOx. An advanced adsorption technology based on acidic gas trap (AGT) absorbers offers the possibility to remove SOx acidic gas from natural gas furnaces with high efficiency and low cost, thereby enabling the development of condensing furnaces without the use of expensive corrosion resistant materials in the heat exchanger. A three-dimensional (3D) computational fluid dynamics (CFD) model has been developed to evaluate the heat transfer performance of a furnace with AGT absorbers and to compare it with a baseline conventional furnace without the AGT. Moreover, an axisymmetric model has been built focusing on the absorbing process in the AGT. The baseline conventional furnace used for the study is a commercial condensing furnace (Rheem 92% AFUE 84,000 BTU Multi-Position Gas Furnace). This furnace was completely disassembled, and the dimensions of each part were carefully measured and used to build a detailed CFD model. A model representing the new furnace, incorporating the AGT absorbers, was developed by adding the AGT system to the conventional furnace model. For the CFD analysis, a mixture model was employed to characterize the heat and mass transfer during the condensing process in the furnace while considering three components — air, water vapor and liquid water. Condensation takes place in the condensing heat exchanger, where water vapor changes phase to liquid water, and the latent heat is thus used in the furnace for useful heating. The simulation results characterize the energy performance of both the conventional furnace and the novel furnace with AGT absorbers, as well as the reactive processing in the AGT. These results provide insightful guidance for the development of the AGT absorber-based furnace from the perspective of its energy performance and will be used to further optimize this novel furnace design.

Ultrafine grain recrystallisation of a metastable-β Ti-alloy via conventional thermomechanical processing

Alloys with ultrafine grains (UFG) offer high strength potentially combined with ductility. Until now, producing ultrafine grains in ingot alloys has required either severe plastic deformation techniques or flash annealing, neither of which are scalable to bulk alloy production. In this work, we formed submicronic grains in the metastable β titanium alloy Ti-20Nb-6Zr (at%), using conventional cold rolling and annealing at 823K in a conventional furnace. The cold rolling (298K) transformed the β structure mostly to α” martensite, but if the rolling temperature was raised to 453K, martensite formation was supressed, and no grain refinement occurred during the subsequent similar annealing treatment. Therefore, we attribute the formation of ultrafine grains to a mechanism involving stress-induced martensite and its reverse transformation.

The Effects of Microwave Postgrowth Processing of BaSrTiO3 Thin Films on Their Dielectric Properties

Tunable complex oxide thin films have generated a lot of interest in recent years due to their potential to become a core technology in the new generation of multiple communications devices. These films are grown via different deposition methods and frequently postprocessed in order to enhance their dielectric properties. This paper discusses an alternative postprocessing technique where complex oxide thin films grown by radio frequency (RF) magnetron sputtering have been treated with an external microwave field instead of a conventional furnace. The treated films and untreated reference film were characterized for their microstructure and dielectric properties. The obtained results indicate a significant reduction in dielectric losses and leakage current in the microwave processed films as opposed to the untreated reference. The results are discussed together with potential additional benefits of the proposed approach.

Verification on Possibility of Nitrogen Diffusion into Steel by High Temperature N-Quench

N-Quench, which is a new surface heat treatment to infiltrate nitrogen into steel parts followed by quenching to achieve hardening, is gathering attention in the nitriding field as it affords low distortion while maintaining a higher effective case depth (ECD) compared with conventional nitriding. N-Quench is conducted mainly between 680°C and 800°C, where the two-phase region of ferrite and austenite exists in the Fe-N phase diagram. However, a few studies have reported on nitriding at temperatures higher than 800°C due to decomposition of NH3, which is a key source of nitrogen infiltration. Our results revealed that in a conventional furnace such as resistance heating furnace, no nitrogen infiltrated the specimen at 930°C, which is the general carburizing temperature. On the other hand, in the infrared heating furnace, nitrogen infiltrated the specimen at 930°C successfully with lesser NH3 introduction than that required by the conventional furnace. Therefore, in this study, the limit of NH3 decomposition is assessed and possibility of extending the applicability of N-Quench, especially increasing the ECD while maintaining a low distortion, is examined.

Evidence of ferroelectric behaviour in CaCu3Ti4O12 thin films deposited by RF-sputtering

The origin of abnormal ferroelectric and unusual piezoelectricity in the polycrystalline CaCu3Ti4O12 (CCTO) thin films deposited by RF-sputtering on Pt/Ti/SiO2/Si (100) substrates was explored. The CCTO thin films, deposited at room temperature followed by annealing at 600?C for 2 h in a conventional furnace, have a cubic structure with lattice parameter a = 7.379 ? 0.001 ? and without any secondary phases. No polarization loss up to 1010 switching cycles, with a switched polarization ?P of 30 ?C/cm2 measured at 400 kV/cm was evidenced. The piezoelectric coefficient investigated by piezoresponse force microscopy (PFM) was approximately 9.0 pm/V. This may be the very first example of exploring the origin of ferroelectric behaviour for a material that possesses space charge polarization with highly resistive grain boundaries in the polycrystalline state.

Investigation of Energy Values in Tender Coconut by Various Methods

Even in 2017 many rural areas the daily food preparation works on conventional furnaces and peat coal as the fuel. It releases lot of smoke and harmful gases. The village blacksmith work also depends on peat coal. One of the alternative fuels for conventional furnace is tender coconut fuel. The tender coconut having lot of mineral values in addition to that it having lot of fuel values. The availability of tender coconut is round the year. In most of the cases these coconuts after drinking simply dumping in the municipal waste or dumping at out cuts of the cities. By making simple process we can convert this tender coconut into good fuel. A special machine designed for process of tender coconut. A detailed analysis done on the tender coconut in two different ways. The total coconut analysis is done two ways, one is on direct coconut where as other is individual elements of the coconut analysis like shell, inner coir, outer coir and coconut husk. The calorific value of each one calculated by using the bomb calorimeter. The exhaust gases also analyzed y using exhaust gas analyzer.

Experimental Study Pertaining to Microwave Sintering (MWS) of Al-Metal Matrix Composite - A Review

Aluminum metal matrix composites (Al-MMCs) is a one of the most demanding engineering material due to the combination of their light weight, excellent mechanical and tribological properties. To enhance the promising advantages of Al-MMCs, microwave sintering (MWS) is an ideal and emerging technique. The unique advantages of MWS of MMCs are ascribed to the size and distribution of the reinforcement, as well as to the grain size of the matrix along with uniform and efficient heating. The objective of this comprehensive review was to highlight the viability of sintering Al-MMC in a microwave oven, and compare the material characteristics of those with similar materials sintered in a conventional furnace.