Effect Of Solution Temperature Research Articles

Effect of Ceramic Nanoparticles on Nanofluids Electrical Conductivity

In this study, an extensive experimental evaluation is conducted on the electrical conductivity of water based nanofluids containing three types of ceramic nanoparticles of (Al2O3, CuO and ZrO2) with different nanoparticles concentrations of (0.05, 0.1, 0.15 and 0.2 vol. %) and for various temperatures ranged by (20-80 °C) by using deionized water as a base fluid. The nanofluids volume (water/nanoparticles) is used at (200 ml). The nanofluid sample mixes slowly by stirring and ultrasonic vibration sonicator with power of (50 W) for a maximum time of (15-20 minutes) to break up any particle aggregates with no any surfactant that is added into the nanofluids to avoid reunion. The electrical conductivity of nanofluids is measured by electrical conductivity meter. Results indicate that the effect of solution temperature on the nanofluids electrical conductivity has little effect in the range of 20–40 °C, but the effect of temperature is increased in the temperature range of 40–80 °C. Also, the percent of electrical conductivity enhancement is 80%, 75% and 50 % when using the nanofluids of CuO, Al2O3 and ZrO2 respectively. Finally, the theoretical model of Maxwell is used to compare with the present experimental results and it gives an agreements.

The interaction between ε-copper and dislocation in a high copper 17-4PH steel

The interaction between ε-copper and dislocation in a high copper 17-4PH stainless steel is investigated as well as the effect of solution temperature, aging temperature and aging time on the microstructure and mechanical properties. Meanwhile, the relationship between precipitates and yield ratio of the steel is also discussed. The conventional tensile test was used to determine the yield strength and ultimate tensile strength. Microstructure of the experimental steel was observed by optical microscope (OM) and transmission electron microscope (TEM). The reversed austenite volume was measured by means of x-ray diffraction (XRD). The results show that the solution strengthening effect improves with the solution temperature in range of 900 °C–1060 °C. The solution temperature, aging temperature and time have a strong effect on the size and content of precipitate phase. It is strengthened through shearing mechanism and Orowan bypass mechanism for 17-4PH steel at the aging temperature of 480 °C while it is dominated by Orowan bypass mechanism at 620 °C. The yield ratio of 17-4PH is depended on the microstructure constituents including the type of soft phase and hard phase.

Heat treatment of Inconel 718 produced by selective laser melting: Microstructure and mechanical properties

Inconel 718 (IN718) samples have been produced by selective laser melting (SLM). The effects of solution temperature, time and cooling rate as well as aging hardening on the microstructure and mechanical properties of SLMed IN718 have been studied. It is found that the as-fabricated IN718 is characterized with fine cellular dendrites with Laves phase precipitating in the subgrain boundaries, which is profoundly different from cast and wrought materials and needs different heat treatment schedules. The relationship between the minimum solution time and solution temperature is established and it provides a basis for the selection of solution treatment parameters. In addition, decreasing the cooling rate of solution treatment will contribute to the precipitation of strengthening phases. The precipitation temperatures of γ′ and γ″ are about the same for SLMed and wrought IN718, but the former has a faster aging response. The tensile properties of SLMed IN718 can be tuned in a large range by properly varying the microstructure. The highest elongation of 39.1% can be obtained after solution treatment (water quenching) without aging treatment and the highest yield and tensile strength (1374/1545 MPa) can be obtained after the direct aging treatment. The match of strength and ductility is able to be tailored by controlling the amount of strengthening phases, which can be realized by adjusting the cooling rate of solution treatment and aging time.

Generating Antibacterial Microporous Structures Using Microfluidic Processing

The aim of this study is to investigate the potential of microfluidic techniques to generate microporous structures, with potential utility as scaffolds, with a highly uniform architecture, possessing an antibacterial activity. Scaffolds were prepared by introducing N2 gas to gelatin (GE)–water or gelatin/hyaluronic acid (GE/HA)–water mixtures to form microbubbles at the interface. The effect of solution temperature on microbubble stability and their structural integrity were studied. A solution temperature of 40 °C produced the best results due to the higher solution viscosity. The effect of different cross-linking concentrations on scaffold swelling ratio was investigated. A concentration of 5% glutaraldehyde was found to be optimal and was chosen to cross-link structure and conduct subsequent degradation and antibacterial experiments. HA was incorporated into the scaffolds owing to its ability to make stable and highly absorbent scaffolds. This led to a decrease in the degradation rate and the introduc...

Electrodeposition of Ferromagnetic FeCo and FeCoMn Alloy from Choline Chloride Based Deep Eutectic Solvent

The electrodeposition of Fe, Co, FeCo, and FeCoMn alloy films has been performed from the choline chloride/urea deep eutectic solvent without additives. The effects of solution temperature, electrolyte concentration, deposition potential, and solution agitation on deposition rate have been studied. Film composition, morphology, crystallographic structure as well as the magnetic moment and coercivity were characterized and compared against the deposition conditions. A dominant mass transport effect was observed across most of the deposition cases. A manganese underpotential deposition phenomenon occurred with the alloy deposition. An elevated temperature results in significantly faster deposition and promotes smooth film growth with limited cracking. As-deposited FeCo alloy films are found to be ferromagnetic and nanocrystalline.

Effect of Heat Treatment on Impact Properties of TC10 Titanium Alloy

The impact properties of TC10 treated with different solid solution temperature were tested. The microstructure change and fracture morphology were observed. The effect of solution temperature on the impact properties of TC10 titanium alloy was studied. The results show that with the increase of solution temperature, the primary alpha phase decreases, when the temperature reached 950 degrees, all of the primary alpha phase changed into the beta phase. From the fracture appearance, the specimen changes from ductile fracture to brittle fracture, impact properties change with the temperature increased first and then decreased, appeared in the middle of a stable maximum value.

Effects of solution temperature and cooling rate on microstructure and micro-hardness of a hot compressed Ti-6Al-4V alloy

The effects of solution temperature and cooling rate on microstructure and micro-hardness of a hot compressed Ti-6Al-4V alloy are investigated. The microstructure observations reveal the occurrence of static recrystallization during solution treatment. The lamellar α phases firstly decompose into the short-rod phases, and then gradually spheroidize. The increased solution temperature can accelerate the transformation of α grain boundary from the low-angle grain boundaries (LAGB) to the high-angle grain boundaries (HAGB). So, the growth and spheroidization of α grains become more and more obvious. Meanwhile, the precipitation of secondary α phases is promoted. The micro-hardness is significantly improved after the solution treatment, i.e., the micro-hardness undergoes the rapid decrease and slow increase with raising the solution temperature. In addition, the cooling rate has great impact on the microstructures and micro-hardness. With reducing the cooling rate, the mean size of equiaxed α grains and the thickness of lamellar α phases obviously increase.

Effect of Solution Treatment on Microstructure and Mechanical Properties of A356.2 Aluminum Alloy Treated With Al–Sr–La Master Alloy

Morphology and mechanical performances of A356.2 aluminum alloy under solution treatment are important for its application, specifically for alloys treated with newly‐developed combined refiner‐modifier. In this work, effect of solution temperature, solution time, and quenching medium temperature on the microstructure and mechanical properties of A356.2 aluminum alloy treated with Al–6Sr–7La master alloy are investigated. Results show that eutectic silicon undergo disintegration, spheroidization, and coarsening stages with solution temperature increasing. Volume fraction of eutectic silicon decreases gradually with solution temperature increasing from 495 to 550 °C, while secondary dendritic arm spacing (SDAS) increases gradually during this process. At the solution temperature of 540 °C, aspect ratio of eutectic silicon approached to about 1.3 and eutectic silicon undergo spheroidization and coarsening stages with extension of solution time. Moreover, SDAS increases with increasing of quenching medium temperature, which affects the ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of the alloy, especially for tensile strength and elongation. Optimal solution parameters for A356.2 aluminum alloy treated with Al–6Sr–7La are obtained and the reasons are discussed.

Areca Plant Extracts as a Green Corrosion Inhibitor of Carbon Steel Metal in 3 M Hydrochloric Acid: Gasometric, Colorimetry and Atomic Absorption Spectroscopy Views

The corrosion inhibition of carbon steel (CS) in 3 M HCl was thoroughly investigated in the presence and absence of areca plant extracts as a green corrosion inhibitor. The effect of solution temperature and different amounts of areca plant extracts was examined through gasometric, colorimeter and atomic absorption spectroscopy techniques. Surface studies were screened by scanning electron microscopy (SEM) technique. The results of these techniques show that areca plant extracts (arecanut husk extract, arecanut seed extract and areca flower extract) behave as a nontoxic corrosion inhibitor for CS in 3 M HCl solution. Areca plant extract (arecanut husk extract, arecanut seed extract and areca flower extracts) shows maximum protection efficiency at 4 g/L extract amount.

Effect of solution heat treatment on microstructure and electrochemical behavior of electron beam smelted Inconel 718 superalloy

Effect of solution heat treatment on microstructure and electrochemical behavior was investigated for the electron beam smelted (EBS) 718 superalloy. The results imply that the solution heat treatment has a great influence on the precipitation behavior of EBS 718 superalloys and thus affects the electrochemical behavior. The increase of solution temperature gives rise to the solution of δ phase for both solution treated and aged EBS 718 superalloys. The 980 °C solution treated and aged EBS 718 superalloy exhibits the maximum content of the volume fraction of γʹʹ phase, in parallel with the highest lattice misfits. Further increase of solution temperature results in the precipitation of dispersively distributed γʹ particles. The pitting potential for the solution treated superalloys increases gradually with increase of solution temperature, and a similar behavior is observed for the aged superalloys with an exception of the alloy processed at 980 °C. The effect of solution temperature on the solution treated superalloys can be elucidated by considering the variation of the volume fraction and the size of δ precipitates. For the aged superalloys, the deterioration effect of Nb rich γʹʹ is obvious due to the tetragonal distortion and accompanying strain field in the nearby matrix. Higher solution temperature results in a uniform distribution of the nano-scale γʹ phase and smallest lattice misfits, with the highest apparent activation energy derived to be 52.86 kJ/mol.

Effects of solution temperature and Cu content on the properties and microstructure of 2:17-type SmCo magnets

The effects of solution temperature and Cu content on the properties and microstructure of Sm (CobalFe0.21CuxZr0.03)7.6 (x = 0.06, 0.08, 0.10) permanent magnets were investigated systematically. The results showed that TbCu7 single-phase was obtained after solution treatment at optimum temperature. The best magnetic properties of Br = 1.010 T and (BH)max = 190.2 kJ/m3 were obtained for Sm (CobalFe0.21Cu0.08Zr0.03)7.6 by a proper solution treatment at 1478 K. At a lower solution temperature, the Co-rich FeCoZr phase was monitored, and a “step” was observed in the demagnetization curves of aged samples. At a higher solution temperature, composition segregation of the matrix gradually occurs, and a Zr-rich SmCoZr phase was found. However, at a slightly higher solution temperature with superabundant Cu, the precipitated phase remained FeCoZr phase, resulting in a worse remanence. All the above changes were related to the cellular structures.

A novel modified screen-printed electrode with triazole surfactant assembled on silver nanoparticles for potentiometric determination of uranium

Potentiometric modified screen-printed electrodes were developed for UO2(II) determination using a triazole-derivative alone (MSPE) or self-assembled on silver nanoparticles- (SNPs-MSPE). The electrodes exhibited excellent potentiometric response characteristics with Nernstian slopes of 26.70 ± 1.02 and 29.90 ± 0.88 mV decade−1 and detection limits of 1.00 × 10−7 and 6.10 × 10−10 mol L−1 for MSPE and SNPs-MSPE, respectively. The electrodes showed fast response times and independent response over a wide pH range. Effect of solution temperature was investigated in the range of 10-60 °C. The optimized electrodes revealed good selectivity for UO2(II) over various interferant and were successfully employed to detect UO2(II) in different real samples.

Photoluminescence behavior in the synthesized CdSe thin films deposited on ITO substrates

Cadmium Selenide nanoparticles (CdSe NPs) deposited on ITO substrates were prepared in aqueous solution by spin-coating method using L-Cysteine as organic stabilizer. The effect of solution temperature (ST) on the morphological and optical properties of CdSe NPs, deposited on ITO substrates was investigated by Atomic force microscopy (AFM), UV–Vis absorption, photoluminescence (PL) and time resolved photoluminescence (TRPL) spectroscopy. Results showed that increasing in the ST up to 70°C improved the crystalline quality of the CdSe NPs, decreased their band gap energy and enhanced the PL intensity. Higher solution temperature induced a reduction in PL intensity with a blue shift of the emission wavelength, which is attributed to quantum confinement effect. The TRPL measurements showed two PL decay times attributed to radiative recombination processes, and the trapping of carriers at the surface states. After heat treatment of the CdSe NCs solution, the decay components were predominated by the fast decay time (89%) suggesting the good surface passivation of nanocrystals.

Effect of Solution Temperature on Microstructure and Mechanical Property of High Temperature Alloy GH2787

Effect of Solution Temperature on Microstructure and Mechanical Property of High Temperature Alloy GH2787

Effect of Solution Treatment on Microstructure and Mechanical Properties of Hot-Extruded Cu-15Ni-8Sn Alloy

The effects of solution treatment on the microstructure evolution of hot-extruded Cu-15Ni-8Sn alloy were investigated by optical microscope (OM), scanning electronic microscope (SEM), differential scanning calorimetry (DSC) and tensile testing, and the effects of solution temperature and time on the mechanical properties of the alloys were analyzed. The results indicated that, the γ-phases precipitated at first and then dissolved with the extension of the solution time during solutionizing at 800 C,the volume fraction of theγ-phase reached its peak at about 1h. However when solutionizing at 860°C, theγ-phase solely dissolved gradually with the extension of the solution time . In addition, a small amount of annealing twins appeared intragranular in the process of solution treatment. The γ-phase dissolution and the grain growth of α (Cu) were the main softening factors of the alloy during the solution treatment. Through overall consideration, the optimum solution treatment was annealing at 840°Cfor 1 h.

Effect of temperature on zeta potential of functionalized gold nanorod

Nanorod immersed in electrolyte solution finds many applications in different fields encompassing biotechnology, drug delivery, micro-/nanofabrication, etc. In this article, a comprehensive theoretical model has been developed and solved numerically to study the effect of nanorod temperature on its potential distribution for different salt concentrations and solution pH. The study considers surface properties of nanorod functionalized with 11-MUA at higher solution temperatures in both the presence and absence of temperature gradient to analyze contribution of thermodiffusion (in the presence of temperature gradient) and different solution properties like ionic mobility and solution permittivity (in the absence of temperature gradient). Effect of solution temperature on nanorod zeta potential in the absence of temperature gradient has been shown through numerical study along with analytical verification. Present results show that zeta potential of nanorod functionalized with 11-MUA is negative, and with increasing nanorod temperature its zeta potential value increases. In the presence of thermodiffusion, increment in zeta potential value strongly depends on solution pH, whereas in the absence of temperature gradient increment in nanorod zeta potential value solely depends on solution permittivity and absolute solution temperature.

Effects of Solution Temperature on Microstructure of 2A66 Al-Cu-Li Alloy

The effect of solution temperature on the solid solubility, microstructure and mechanical properties of 2A66 Al-Cu-Li alloy was studied by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile test. The results show that with the solution temperature increasing from 480°C to 520°C,the amount of residual phases decreased and the solid solubility increased obviously, while the recrystallization hardly changed with the increasing of solution temperature. With the solution temperature increased to above 530°C, the amount of residual phases almost did not change. With the solution temperature increasing to above 540°C, the alloy was over-burnt obviously. Complete dissolution of the particles in the 2A66 Al-Cu-Li alloy was obtained after solution treatment at 520°C.

Application of integrated forward and reverse osmosis for coal mine wastewater desalination

Abstract Water management is an integral part of coal mining operations. Due to the constraints on releasing saline water, coal mines require additional water storage facilities and therefore seek to minimise their inventory of saline water. Adopting efficient treatment technologies on-site would minimise the risk of wet season run-offs, freshwater contamination and allow segregation of different qualities of water to enable greater water recycling. This study aims to evaluate the application of an integrated forward osmosis (FO) and reverse osmosis (RO) system with three different actual coal mine waters, containing various concentrations of sulphates and silica that are generally associated with scaling and fouling of membrane systems. Three different FO draw solutions, di-sodium hydrogen phosphate (DHSP), sodium hexametaphosphate (SHMP) and sodium lignosulphonate (SLS) were evaluated. Two different modes of integrating the FO and RO systems were identified. The integrated system was able to concentrate the brackish mine waters, recovering more than 80% of the volume of mine water and obtaining dischargeable quality treated water. Simple physical cleaning with clean water circulation was found to be effective in restoring the FO water flux. The osmotic gradient between two mine waters was also utilised to adopt mine water as a draw solution. The effect of solution temperature on stand-alone and integrated FO and RO systems was also evaluated. The combination of FO with RO provided a better performance than individual FO or RO in treating coal mine wastewater. The FO unit served as an effective pre-treatment system prior to RO and the integrated FO–RO systems has a strong potential to successfully eliminate conventional pre-treatment processes for RO.

Influence of solution treatment on microstructure evolution of TC21 titanium alloy with near equiaxed β grains fabricated by laser additive manufacture

Laser additive manufacture (LAM) is a novel technique in which metal components can be fabricated layer by layer. In this paper, the effects of solution temperature and cooling rate on microstructure evolution of the LAMed TC21 titanium alloy which containing near equiaxed prior β grains were studied. The LAMed and solution treated samples were investigated by optical microscopy (OM), scanning election microscope (SEM) and X-ray diffractometer (XRD). The results indicate that both the α phase volume fraction and α laths width are affected by the solution temperature and cooling rate. Different microstructure characterization leads to different Vickers hardness values. However, the solution temperatures selected in this study have insignificant effects on the β and α phase texture. The near equiaxed prior β grains exhibits much weaker texture intensity than the typical columnar prior β grains. The comparison of the calculated and measured α phase texture indicates that variant selection occurred during the solution treatment. The martensite α′ phase precipitated during the layer by layer process shows weak variant selection tendency.

Temperature-dependent corrosion behaviour of flame-resistant, Ca-containing AZX911 and AMX602 Mg alloys

The effects of solution temperature on the corrosion characteristics of Ca-containing AZX911 and AMX602 Mg alloys were investigated in 0.1MNaCl solution and compared with those of AZ91 and AM60. AZX911 and AMX602 comprise an α-Mg matrix having an spherical Al2Ca phase dispersed therein; the Al2Ca on AMX602 was approximately twice the amount that on AZX911. Severe corrosion was occurred on both AZX911 and AMX602 at 40°C and above. In particular, AMX602 was corroded more rapidly, which means that the Al2Ca is not capable of blocking the corrosion at the high temperature due to strong galvanic cathode effect.