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In the present work, the thermal conductivity (TC) of stable water base fly ash and fly ash-Copper (80:20 vol.%) nanofluid was determined experimentally in the temperature range of 30–60 °C for the...

Thermal conductivity, dynamic viscosity, and density of TiN nanofluids (NFs) with different base mediums have been characterized for the prospect of developing new thermophysical property correlations in this work. Characterizations of morphology and crystal structure of nanopowder were made using scanning electron microspore and X-ray diffractometer. Set of NFs was prepared in a base liquid mixture of water–ethylene glycol W/EG 60:40 and 40:60 by an ultrasound-assisted two-step method. Meter Group KD 2 Pro analyzer operated on transient line heat source method was used for the thermal conductivity test. The viscosity and density of NFs were measured with Anton Paar rotational rheometer MCR 302 and oscillating densimeter DMA 4500M. All experiments were implemented for volume fractions of NF between 0.25 and 1.0 vol% in the temperatures range of 293.15–333.15 K. The findings indicate that density and viscosity decrease with increasing temperature, whereas the thermal conductivity of nanofluids is enhanced depending on NP concentration. The W/EG 60:40 base mixture exhibited higher thermal conductivity enhancement and 40:60 base mixture had greater viscosity growth among all analyzed NFs. Moreover, the difference in base fluid fractions does not lead to a significant variance in the density ratios of NFs. Empirical correlations developed for examined properties with effects of particle concentration, temperature, and base liquid ratio are capable of accurately reproducing the properties data within 15% deviation.

The experimental data on the viscosity and thermal conductivity (TC) of ethylene glycol (EG)-based hybrid nanofluids (HyNFs) dispersed with a SiC–CuO/C nanocomposite (NC) is reported for the first time. The rheological behavior and dynamic viscosity have been analyzed with a computer controlled rotational rheometer over a temperature range from 298.15–353.15 K and shear rate from 20 to 200 s−1. The TC was measured using transient hot-wire method for NF concentrations up to 3.13 wt%. The effect of the temperature and volume fraction of the nanoparticles (NPs) on the thermophysical properties were examined under atmospheric pressure. The experimental findings revealed that the TC increases with the concentration and temperature, while the viscosity increases with concentration and decreases with temperature as expected. HyNF exhibit substantially higher TC and viscosity enhancement compared to single-particle based NF under similar conditions. The enhanced properties of the HyNF could be attributed to the synergetic effects of the composite particles and the underlying physical mechanism in the fluid medium. The existing theoretical models failed to predict the experimental data. Herein, a new correlation is presented as a function of concentration and temperature for the TC and viscosity.

This paper reports experimental investigation on the viscosity, electrical and thermal conductivities of ethylene glycol and propylene glycol based β-SiC nanofluids. Two-step technique was used to formulate stable nanofluids at room temperature. The properties of nanofluids were measured at temperatures between 298.15 K and 353.15 K for different concentrations up to 3.0 wt.% loading (1.0 vol.%). The effect of temperature and base liquid was analysed on each of nanofluid sample. The experimental results showed that both electrical and thermal conductivity increase while viscosity decreases with temperature. The properties of the base liquid are found to influence the nanofluid properties. The underlying mechanisms have been established and discussed. Furthermore, some new empirical equations are derived to correlate the measured properties data. The results can be applied to predict the viscosity, electrical and thermal conductivities of ethylene glycol and propylene glycol-based β-SiC nanofluids.

The turbulent characteristics of heat transfer and flow have been determined by applying the Van Driest model of the eddy diffusivity for water and ethylene glycol-based nanofluids. The properties of CuO, Al2O3 and SiO2 nanofluids in two base liquids viz., water and EG-water mixture with the ratio of 60:40 are considered for various concentrations and bulk temperature ranges. Based on the observations, it is concluded that numerical outcomes are validated with experimental measurements for heat transfer properties. It is monitored that SiO2 reaches a higher temperature gradient in comparison to CuO at a similar temperature and concentration in EG-water with the mixture of 60: 40. The gradients are greater for the EGW mixture compared to water-based nanofluids. However, the water-based nanofluids have higher heat transfer coefficients compared to EG-water nanofluid at identical flow velocities.

Hybrid nanofluids are a novel class of colloidal fluids which have drawn significant attention due to potential tailoring of their thermo-physical properties for heat transfer enhancement by a combination of more than one nano-additive to meet specific requirements of an application. In the present work, ceramic copper oxide/carbon (SiO2-CuO/C) nanoparticles in 80:20 (wt%) composition were prepared by ultrasonic-assisted wet mixing technique. The hybrid nanofluid was formulated by dispersing the nanoparticles into a base fluid mixture of 60:40 (% by mass) glycerol and ethylene glycol (G/EG) using the two-steps method. The influence of nanoparticles on the augmentation of specific heat, thermal conductivity and viscosity was examined in the volume concentration range of 0.5–2.0% in the temperature range of 303.15–353.15 K. The results demonstrate that the synthesized SiO2-CuO/C hybrid nanoparticles enhanced the thermo-physical properties of the base fluid mixture which is higher than using SiO2 alone. In the case of SiO2–G/EG nanofluid, the specific heat capacity decremented by a maximum value of 5.7% whereas the thermal conductivity and viscosity incremented by 6.9% and 1.33-times as compared with G/EG at maximum volume concentration of 2.0% at a temperature of 353.15 K. Comparatively, a reinforcement of 80% SiO2 with 20% CuO/C in G/EG mixture led to thermal conductivity and viscosity enhancement by 26.9% and 1.15-times, respectively with a significant reduction of specific heat by 21.1%. New empirical correlations were proposed based on the experimental data for evaluation of thermophysical properties.

In recent years, research is focused on enhancing the thermo-physical properties of single component nanofluids. Hence, the hybrid or composite nanofluids are developed to enhance the heat transfer performance. The thermo-physical properties of TiO 2 -SiO 2 nanoparticles suspended in a base fluid of water (W) and ethylene glycol (EG) mixture with 60:40 vol ratio are investigated. The experiments were conducted for 1.0% volume concentration of TiO 2 -SiO 2 nanofluids with different mixture ratios of 20:80, 40:60, 50:50, 60:40 and 80:20. The measurements of thermal conductivity and dynamic viscosity were performed in the temperature range of 30–80 °C by using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV III Ultra Rheometer respectively. The highest thermal conductivity for TiO 2 -SiO 2 nanofluid was obtained with a ratio of 20:80 and the maximum enhancement exceeded up to 16% higher than the base fluids. The nanofluids with a ratio of 50:50 provided the lowest effective thermal conductivity. Meanwhile, the dynamic viscosity variation for all mixture ratios is always lower than the ones with a ratio of 50:50. The properties enhancement ratio suggests that TiO 2 -SiO 2 nanofluid with 1.0% volume concentration will aid the heat transfer for all mixture ratios except for the ratio of 50:50. As a conclusion, the optimum mixture ratios for TiO 2 -SiO 2 nanofluids are attained with 40:60 and 80:20 ratios where the combination of enhancement in thermal conductivity and dynamic viscosity had more advantages to heat transfer as compared to other ratios.

The purpose of the current research work is to investigate the various properties like thermal conductivity, stability and viscosity of copper and a mixture of fly ash-Copper (FA:Cu) nanoparticles (NP) suspended in water. The research experiments were conducted for a concentration of 1.0 vol% of FA:Cu hybrid nanofluid (HNF) with various mixture ratios. The measurements of thermal conductivity and viscosity were performed in the 30–60 °C temperature range. The highest thermal conductivity and viscosity values for HNF with a mixture ratio of 20:80 were obtained with a maximum amplification exceeding 83.2% and 65% than the base fluid, respectively. The properties enhancement ratio (PER) reveals that HNF with 1.0 vol% concentration enhances heat transfer for all defined mixture ratios in the reported research work. Finally, the predictability potential of an ensemble-based machine learning technique called Boosted Regression Tree (BRT), based on nanofluids temperature (T) and mixture ratio (R), were compared with the classical regression approach to simulate the thermo-physical properties of HNF. The outcomes of the BRT model in terms of (r(viscosity) = 0.9953 and r(thermal conductivity) = 0.9991) superior to the regression method with (r(viscosity) = 0.9695 and r(thermal conductivity) = 0.9539) over the viscosity and thermal conductivity prediction process.

In the present study, titanium oxide-copper oxide/carbon (TiO 2 -CuO/C) nanocomposite particles have been prepared via wet-mixing protocol. The nanocomposite was characterized by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction (XRD). Subsequently, hybrid nanofluids were prepared by dispersing the nanocomposite in ethylene glycol (EG) as a base liquid. The thermal conductivity and viscosity of the nanofluids was measured in various volume concentrations (0.5, 1.0, 1.5, and 2%) and temperatures ranging from 303.15 K to 333.15 K. The experimental results showed the sensitivity of thermal conductivity and viscosity with respect to variations in volume concentration and temperature. The maximum enhancement of thermal conductivity of TiO 2 -CuO/C hybrid nanofluid is 16.7%, while the viscosity increased nearly by 80% at 2.0% volume concentration compared to base liquid at 313.4 K. The rheological analysis established that the hybrid nanofluid conforms to Newtonian classification of fluids. Finally, correlations for thermal conductivity and viscosity of nanocomposite based hybrid nanofluids were formulated which represent a satisfactory agreement between the experimental and calculated data with average absolute deviation ranging from 1% to 4%.

In this paper, laminar nanofluid flow in 3D copper microchannel heat sink (MCHS) with rectangular cross section, and a constant heat flux, has been treated numerically using the computational fluid dynamics software (FLUENT). Results for the temperature and velocity distributions in the investigated MCHS are presented. In addition, experimental and numerical values are compared in terms of friction factors, convective heat transfer coefficients, wall temperature and pressure drops, for various particle volume concentrations and Reynolds numbers. The numerical results show that enhancing the heat flux has a very weak effect on the heat transfer coefficient for pure water, but an appreciable effect for the case of a nanofluid. For all considered volume fractions, the sink friction factor decreases by increasing the Reynolds number and slightly increases by increasing the volume fractions, and, with increasing the volume fractions and the Reynolds number, the pressure drop increases.

Nanofluids are developed to meet the challenges of improving the efficiency of the cooling system subsequently minimizing the energy waste. This paper aims to investigate the forced convection heat transfer for Al2O3 nanofluids in different based ratio of water (W) and ethylene glycol (EG) mixture. The Al2O3 nanofluids are formulated using the two-step method for three based mixture ratio of 60:40, 50:50 and 40:60 (W:EG) by volume. The forced convection experiments are conducted under constant heat flux conditions for operating temperatures of 30–70 °C and Reynolds numbers of 3000–25,000. The heat transfer coefficient of nanofluids is enhanced with concentration compare to its base fluid at all designated temperature. It is observed to be improved further with the increase of temperature. The effect of different base mixture ratio display that nanofluids in 60:40 base mixture have the highest percentage of performance with 24.6% enhancement at 1.0% concentration and temperature of 70 °C. The increment of concentration for nanofluids shows a slight rise in friction factor. As a conclusion, the thermo-physical properties and the forced convection heat transfer for nanofluids in various base mixture is significantly influenced by concentration, temperature and base ratio of mixture.

The limitation of the conventional fluids to facilitate cooling/heating rates remains the primary basis for exploring alternative heat transfer nanofluids. Research efforts on nanofluids have evolved over the past two decades in establishing extensive literature. Several models for thermophysical properties were made available to characterize the behaviors of diverse individual nanofluids. However, lack of reasonable agreement between theory and experimental results has been a limiting factor for the development of a unified nanofluid model for thermal conductivity. Existing models for thermo-physical properties of nanofluids such as density, specific heat, thermal conductivity, and viscosity are critically surveyed and appropriate equations are extended for composite nanofluids. Consequently, based on reliable models identified predictions for thermal conductivity and viscosity for composite nanofluids are presented. Overall results show that existing thermophysical models for density and specific heat are valid for all water based oxide nanofluids for both single material and composites whereas models for thermal conductivity and viscosity show selective response but have the versatility for predicting the behavior of single and composite nanofluids within acceptable deviation.

From a regression analysis perspective, this paper focused on literature about TiO2 nano particles. The particles on focus entailed those that had been suspended in ethylene glycol and water – at a ratio of 60:40. Indeed, regression analysis has gained application in contexts such as the turbulent Reynolds number, especially with the aim of establishing the impact of the ratio of the base fluid on heat transfer coefficients, as well as the target materials’ thermal properties. From the findings, this study infers that when the water-ethylene glycol mixture is used at a ratio of 60:40, the rate of heat transfer is higher than that which is obtained when water is used solely. Additional findings established from the examination of the impact of material concentration and temperature on the rate of nanofluids’ heat transfer suggested that as temperature increases, the rate of heat transfer decreases. However, it was noted that an increase in concentration exhibits a positive correlation with the nanofluids’ rate of heat transfer whereby an increase in the former parameter (concentration) leads to an increase in the latter (rate of nanofluids heat transfer).

In the present work, medium density fiberboard (MDF) panels were produced using multiwalled carbon nanotubes (MWCNT) reinforced urea formaldehyde resin. Response surface methodology was employed to optimize the relationship between the three variables, viz. pressing time, percentage of UF resin and percentage of MWCNT, used in the fabrication of MDF, and the influence of variables on the internal bonding (IB) and modulus of rupture (MOR) was studied. The optimum conditions based on the IB strength were determined as 8.18 % of UF resin, pressing time of 232 s, and MWCNT of 3.5 %. Similarly, the optimized conditions for MOR are also reported in this paper.

Nanofluids as a new coolant have overcome the limitations in thermal performance faced by conventional fluids such as water, ethylene glycol (EG) and oil based fluids. The objective of the study is to investigate the properties and heat transfer performance of TiO2 nanofluids in water-EG mixture at different operating temperatures. The study is carried out through experimental determination on heat transfer coefficient of TiO2 nanofluids in a circular tube under turbulent flow. The thermal conductivity and viscosity measurements were undertaken for temperature in the range of 30–80 °C. The maximum enhancement of thermal conductivity achieved was 15.4% at 1.5 vol% concentration and temperature of 60 °C. The relative viscosities fluctuate at a range of 4.6–33.3% with variation of temperature. The Nusselt number showed an enhancement up to 22.8% and 28.9% for temperatures of 50 °C and 70 °C, respectively. The friction factor for the nanofluids is slightly increased with concentration. Thermal conductivity, viscosity and heat transfer coefficient of TiO2 nanofluid are strongly influenced by working temperature and concentration.

This paper introduces the historical background about the development of water based, ethylene glycol (EG) based and EG:water mixture nanofluids for the past 20 years. The primary consideration is to review the salient of research work related to EG:water mixture nanofluids and their applications. Nowadays, the fundamental studies of nanofluids are increasing rapidly for engineering applications. The determination of the forced convection heat transfer and pressure drop was reviewed for nanofluid flow in a tube. The experimental and numerical heat transfers of nanofluids were presented. A review of other relevant research studies is also provided. Substantial heat transfer literature has been studied on water based nanofluids used in the fundamental study for engineering applications. However, there are limited studies that use EG:water mixture nanofluids in evaluation of forced convection heat transfer. A number of research studies have been performed to investigate the transport properties of EG:water mixture nanofluids either in experimental or numerical approach. As the performance of EG:water mixture nanofluids could be verified through experimental studies, researchers have conducted the experimental works using several types of potential nanofluids. As a result, nanofluids have been used in certain engineering applications such as in automotive, transportation, cooling of electronics components, solar, and nuclear reactor coolant.

Nanofluid as a new brand of cooling fluid consisting of nanometer-sized particles dispersed in base fluid. In this study, the thermal conductivity and electrical conductivity of BioGlycol (BG)–water (W) mixed nanofluids containing Al 2 O 3 nanoparticles were studied. Nanofluids with 0.5–2.0% concentrations were prepared by the two-step method. The nanofluids demonstrated excellent stability over the temperature range of 30–80 °C after using the long term sonication process. Comparisons of the experimental data with many existing models illustrated that they do not display good agreement. Therefore, a new nonlinear model has been developed with 5% maximum deviation for the thermal conductivity of nanofluids as a function of temperature and volume concentration. The results of BG:W mixtures have displayed improvement in thermal performance of 7.5% in comparison with propylene glycol (PG):W in similar circumstances. The thermal conductivity of nanofluid increased as a function of volume concentration and temperature. The maximum thermal conductivity enhancement using 40:60% (BG:W) mixture ratio was twice as high as 60:40% in the same conditions. Electrical conductivity was observed to decrease as the volume concentration increased. Thermo-electrical conductivity ratio (TEC) has been evaluated theoretically based on thermal and electrical conductivity results.

Nanofluids are a new class of engineered thermal fluids with enhanced thermal properties and heat transfer capabilities exceeding those of the base liquid. Studies related to the effect of temperature on the thermophysical and rheological properties of ethylene glycol and glycerol nanofluids have been documented in various articles. In this paper, the thermal and physio-chemical behavior of SiC nanofluid dispersed in glycerol and ethylene mixture of 60:40 wt.% ratio was determined. The influence of temperature on the p H, viscosity, electrical and thermal conductivity of nanofluid was undertaken for a maximum concentration of 1.0 vol.% in the temperature range of 15-75 o C. It was found that, the base liquid electrical conductivity and p H were unaffected by temperature; whereas the nanofluid electrical and thermal conductivity increased with temperature. The viscosity of the base liquid and nanofluid decreased significantly while the decrease in p H is not significant with temperature.

This paper involves a numerical study of several water – ionic liquids mixtures and nanoparticle enhanced ionic liquids starting from a less studied ionic liquid: 1-Ethyl-3-methylimidazolium Methanesulfonate, [C2mim][CH3SO3]. The research start point was several previous published experimental results in regard to the water – ionic liquid mixtures and alumina based nanoparticle enhanced ionic liquids thermophysical properties. Consequently, all the considered fluids are completely described and can be successfully implemented in a numerical analysis using the single phase approach. The numerical analysis was performed in a cylindrical enclosure considering laminar steady state and results were collected in terms of Nusselt number, convective heat transfer coefficient, pressure drop and temperature on tube exit. Results were discussed in terms of heat transfer enhancement and pumping power requirement variation, as well as field synergy. Concluding, it can clearly say that mixing water with [C2mim][CH3SO3] ionic liquid it gets a decrease in laminar convective heat transfer coefficient, while adding nanoparticles the heat transfer is enhanced by maximum 50%, depending on the alumina mass concentration.

Catalyst-free carbon nanospheres were synthesized using simple one-step pyrolysis techniques where biowaste sago bark is used as a carbon precursor. Obtained carbon nanospheres showed a porous nature and revealed that more than 95% carbon is present in the synthesized carbon nanospheres with particle size ranging from 40 to 70 nm. An electrochemical study showed a specific capacitance value of 180 F g–1 at 2 mV s–1 and the cycling stability up to 1700 cycles. Obtained carbon nanospheres are useful in supercapacitor applications. The presented study revealed a waste to wealth approach thereby reducing waste in the environment.

A single step and simple pyrolysis technique is used to prepare carbon nanospheres (CNSs) from natural biowaste sago hampas in a nitrogen atmosphere without any catalyst. Scanning electron microscope (SEM) images along with transmission electron microscope (TEM) images show evidence of high quality CNSs with a good particle size uniformity. Both X-ray diffraction (XRD) and Raman data show the presence of graphitic characteristic peaks of CNSs. Zeta-potential study reveals that the obtained CNSs can be well dispersed in solution making them suitable for cell imaging applications. The use of biowaste sago hampas is very important from the viewpoint of sustainable synthesis of functional CNSs for the future.

Nanostructured ceramic materials have recently attracted attention as promising heat transfer fluid additives owing to their outstanding heat storage capacities. In this paper, experimental measurements of the specific heats of SiO2–Glycerol, SiO2–Ethylene Glycol, and SiO2–Glycerol/Ethylene Glycol mixture 60:40 ratio (by mass) nanofluids with different volume concentrations of 1.0–4.0% have been carried out using differential scanning calorimeter at temperatures of 25 °C and 50 °C. Experimental results indicate lower specific heat capacities are found with SiO2 nanofluids compared to their respective base fluids. The specific heat was decreasing with the increase of concentration, and this decrement depends on upon the type of the base fluid. It is observed that temperature has a positive impact on the specific heat capacity. Furthermore, the experimental values were compared with the theoretical model predictions, and a satisfactory agreement was established.

In the present work a small percentage of activated charcoal was added in the thermosetting urea–formaldehyde (UF) resin and the performance of adhesives and wood composite was observed. The effect of activated charcoal on the curing kinetics and the Crosslink density of UF resin was investigated, using differential scanning calorimetry. The activated charcoal has an accelerating effect on the curing of the UF resin. The Crosslink density of resin increases and the activation energy decreases. The influence of the activated charcoal addition was particularly noted in medium density fiberboard by the increase in the value of modulus of rupture and internal bond strength of the panel, a direct indication of the performance improvement with the addition of a small amount of activated charcoal. The formaldehyde emission significantly decreases with the addition of activated charcoal.

In this study, the effect of Al2O3 nanoparticles on the heat-transfer properties of medium density fiberboard (MDF) was investigated. Al2O3 nanoparticles were added at two levels (0.5 and 1.0 %) by percentage weight fraction of dry wood fibers to urea formaldehyde (UF) resin. The core temperature profile and thermal conductivity tests showed higher rate of heat transfer after addition of nanoparticles, subsequently it has improved the bonding strength of MDF. Differential scanning calorimetry was used to estimate the heat evolved during the exothermic reaction of UF resin curing. Scanning electron microscopy shows good dispersion of nanoparticles. Thermal conductivity of UF resin improved after nanoparticles addition proved by KD2 pro results. Modulus of rupture, modulus of elasticity and thickness swelling also improved.

Palm oil is one of the vegetable oil, which is converted to biodiesel through a transesterification process using methanol as the catalyst. Palm oil biodiesel or palm methyl ester (PME) can be used in diesel engines without any modification, and can be blended with conventional diesel to produce different proportions of PME-diesel blend fuels. The physical properties of PME were evaluated experimentally and theoretically. The effect of using neat PME as fuel on engine performance and emissions was evaluated using a commercial four-cylinder four-stroke IDI diesel engine. The experimental results on an engine operated with PME exhibited higher brake specific fuel consumption in comparison with the conventional fuel. With respect to the incylinder pressure and heat release rate, these increased features by over 8.11% and 9.3% with PME compared to conventional diesel. The overall results show that PME surpassed the diesel combustion quality due to its psychochemical properties and higher oxygen content.

The nanofluid used was a stable colloidal suspension of magnetite (Fe 3 O 4 ) nanoparticles of average diameter 36 nm. The convective heat transfer coefficient and friction factor characteristics of Fe 3 O 4 nanofluid for flow in a circular tube is evaluated experimentally in the range of 3000 φ

Forced convection heat transfer coefficient and friction factor are determined for flow of water and nanofluid in a vertical packed bed column. The analysis is undertaken in the laminar and transition Reynolds number range. The column is filled with spherical glass beads as the bed material. The heat transfer coefficients with Al2O3 nanofluid increased by 12 to 15% with the increase of volume concentration from 0.02 to 0.5% compared to water. The experimental values of axial temperature are in good agreement with NTU-? method proposed by Schumann's model.

A comparison study was done with untreated and pretreated Pongamia and Jatropha methyl esters for recovery and fuel properties. It is observed that the pretreatment of the seeds enhanced the yield of Pongamia and Jatropha methyl esters. Pretreated methyl ester showed considerable reduction in viscosity, fire, and flash points and cloud and pour points and increased the heat value and American Petroleum Institute gravity. All these properties of fuel were found to be better than that of untreated seeds, making it suitable for use in internal combustion engines and with the possibility of having reduced maintenance problems.

A mathematical model was developed for the study of external turbulent film condensation of pure vapours flowing downward and normal to the axis of the condenser tube with constant heat flux conditions maintained at the tube wall. The magnitude of interfacial shear was estimated for a given external flow condition of the vapour with the help of Colburn’s analogy. The average condensation heat transfer coefficients for different system conditions were evaluated. The present theory was compared with the available experimental and theoretical data in the literature and was found to be satisfactory.

The influence of various parameters on oxygen stripping for a two stage spray and tray type de-aerator is analyzed experimentally. It is observed that increasing the mass flow rate of water leads to an increase in heat and mass transfer coefficients in both stages. There is no significant influence of de-aerator pressure and length of the second stage on the heat transfer coefficients in the range tested. The increase in de-aerator pressure enhances the mass transfer coefficient by 14 percent, whereas the increase in length of the second stage has no significant influence. The empirical correlations available in the literature predict the mass transfer coefficients satisfactorily in the experimental range tested. The total length of the de-aerator is a significant parameter influencing the quantity of oxygen removed from the feed water.

Deaerator is used to remove oxygen from boiler feed-water. Experiments with deaerator indicate that the droplet diameter decreases with increasing the mass flow rate of water and the increasing deaerator pressure leads to increase in heat and mass transfer coefficients. The mass transfer coefficients are found to increase with increasing the deaerator pressure, the independent of length and the oxygen concentration in inlet water.

This experimental investigation deals with nucleate boiling studies on horizontal cylindrical heating elements made out of copper in the medium of Forane around atmospheric conditions. The data could be successfully correlated with the system of criteria employed by the authors in their earlier study of nucleate boiling process on cylindrical heating elements. Inclusion of the data from the present experimental study on Forane and that of other investigators yielded a comprehensive correlation with an average deviation of 20% and standard deviation of 25% over a wide range of system pressures.

A numerical analysis for the determination for turbulent characteristics of fluid flow and heat transfer have been developed by employing the eddy diffusivity equation of Van Driest. The properties of Silicon dioxide (SiO 2 ) nanofluid with spherical particles in base liquid ethylene glycol (EG) -water (W) mixture of 60:40 ratio is employed for a wide range of concentrations and bulk temperature. A good agreement of the numerical results with the experimental data for properties and heat transfer is observed. A comparison of Copper oxide (CuO), Aluminum dioxide (Al 2 O 3 ) and Silicon dioxide (SiO 2 ) nanofluids revealed that SiO 2 attain higher temperature gradients in comparison to CuO nanofluid at the same concentration and temperature.

Aluminum oxide nanoparticles were used as nanofillers in urea-formaldehyde (UF) resin and prepared for medium density fiberboards (MDF). The nanofillers composed weight percentage of the UF resin. The thermal and viscoelastic properties were studied using differential scanning calorimetry and dynamic mechanical analysis. The H value of the UF resin showed an increase with increasing nanoparticle concentration. The core temperature during hot pressing increased with the addition of nanofillers. The formaldehyde emissions from MDF decreased with an increase in the concentration of nanofillers. The internal bonding strength and the modulus of rupture of boards were improved significantly after nanoparticle loading.

Structure of the alumina, silica and NaY zeolites supported Co and Ru catalysts determined by XRD, XPS and TPR, and its activity in low temperature methane activation measured by deuterium uptake were investigated. Formation of CH X species is affected by the nature of metal (e.g. methane dissociation occurs on Pt to a lesser extent than on Co and Ru), by the metal/support interaction causing difficulty in reduction of metals and the metal particle size.

Thermal conductivity properties of water-based nanofluids at low concentrations are being presented in this paper. Nanoparticles at low volume concentration in the range of 0.01 to 1% is added to water improve the properties of the base fluid. The properties are estimated at temperatures between 21°C and 45°C. The results indicate an increase of enhancement of thermal conductivity with temperature and are found to be in agreement with different models as well as the data published in the literature. Empirical equations to calculate thermal conductivity and density for varied particle concentration and temperature are established. The measured and predicted values of thermal conductivity and density have a maximum deviation of 8% and 6% in the working range, respectively.

The main aim of the present investigation is to study the heat transfer behaviour of nanofluids in a circular tube under laminar flow condition by using commercially available FLUENT 6.0 software. In this analysis Al2 O2, CuO and TiO2 nanofluids are considered. Thermo-physical properties of the nanofluids (thermal conductivity, density, viscosity and specific heat) are obtained from the literature. Constant heat flux boundary condition is applied for the estimation of heat transfer coefficient of nanofluids inside a tube. All the investigations of nanofluids are carried out in the volume concentrations ranging from 0.3-2.0% and at the same Reynolds number. The values obtained from CFD analysis of nanofluids are compared with the values of water.

This paper describes the wear mechanism and tool life when machining Hastelloy C-22HS with coated carbide. The experiment was conducted using four different cutting tool materials under wet condition – namely, Physical Vapor Deposition (PVD) coated with TiAlN; TiN/TiCN/TiN; Chemical Vapor Deposition (CVD) coated with TiN/TiCN/Al2O3; and TiN/TiCN/TiN – to study the tool behavior, in terms of wear and tool life machining of Hastelloy C-22HS. Tool failure modes and wear mechanism were examined at various cutting parameters. Flank wear, chipping, notching, plastic lowering at cutting edge, catastrophic and wear at nose were found to be the predominant tool failure for the four types of cutting tools, especially with CVD tools. Attrition/adhesion, oxidation and built-up edge (BUE) are the wear mechanisms observed in all cutting tools. The results obtained indicated that PVD cutting tools performed better than CVD cutting tools, in terms of tool life with current parameters.