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The kinematic viscosity of three kinds of nanofluids namely Al2O3/water, TiO2/water, and graphene/water was measured at different temperatures. Concentration of the metallic oxide nanoparticles in ...

Two novel methods for spectrophotometric determination of Cu2+ ion using synthesized and characterized furfuraldehyde fluorescein diacetate hydrazone (FFDH) and furfuraldehyde fluorescein hydrazone (FFH) have been proposed. Addition of Cu2+ to FFDH and FFH solutions results in a rapid color change from colorless to dark yellow. Experimental results show that FFH and FFDH both can provide a rapid, selective and sensitive response to Cu2+ within a linear dynamic range of 7–33 µM and the detection limits of 1.1 × 10–7 and 7 × 10–8 M, respectively. Apparently, the detection limit of FFDH is lower than that of FFH, which indicates that FFDH forms a more stable complex with Cu2+. In addition, the detection of Cu2+ in water samples was also studied; as a result, the developed FFDH was found to be more applicable than FFH for spectrophotometric determination of Cu2+ in environmental water samples. Particularly, as a lipid chemical compound, FFDH may be transported across the cell membrane to detect Cu2+ in vivo. It is of great significance in many fields, such as biology, biochemistry, medicine and environment.

The aim of this research is to investigate experimentally the characteristics of the convective heat transfer and exergy analysis of pure water and water based Al2O3 nanofluid through helical coiled tubes (HCTs) and conical coiled tubes (CCTs) inside shell and coil heat exchangers. HCT and CCT fabricated with different coil torsions (λ) ranges from 0.0202 to 0.052 with different two angles (0° and 45°) while have the same curvature ratio (δ = 0.0564). The effects of mean coil torsion, the cone angle and nanoparticles volume concentration on the thermal performance were investigated. Results indicated that the overall heat transfer coefficient (Uov), convection heat transfer coefficient (ht), the tube side Nusselt number (Nut), effectiveness (ɛ) and exergy efficiency (ηex) of nanofluids are higher than those of the pure water at same flow condition, and this increase goes up with the increase in particle volume concentration (ϕ). The results also showed that Uov, ht, Nut, ɛ and ηex increases by decreasing the coil torsion from 0.052 to 0.0202. Correlations for Nut as a function of the investigated parameters are obtained.

The properties including oil content, density, high viscosity, and corresponding components were analyzed in the samples of the oil-contaminated soil from one country in the Middle East; also, chem...

Synergistic effect of MWCNTs-COOH and Ag nanoparticle on improving thermal conductivity of hybrid nanofluid has been explained experimentally in this paper. Different concentrations of MWCNTs/water nanofluids (0.004, 0.008, 0.04 and 0.16 vol%) were used and mixed with (0.04 vol%) Ag nanoparticle to prepare hybrid nanofluid. TEM was employed for confirming the size of MWCNTs and Ag nanoparticles in base fluids. Furthermore, SEM and XPS were utilized to characterize the prepared hybrid nanofluid. The hybrid nanofluids’ thermal conductivity was measured in varying volume fractions at 20–50 °C temperatures. As shown by the results, the ratio of thermal conductivity of hybrid nanofluids is increased in a nonlinear manner as the concentration and temperature increase. It was seen that the hybrid nanofluid’s thermal conductivity having 0.04 vol% Ag nanoparticles and 0.16 vol% MWCNTs was synergistically improved by 47.3% in comparison with thermal conductivity the water base fluid. In the end, new thermal conductivity ratio correlation was suggested on the basis of the empirical data. Comparisons of correlation output and experimental thermal conductivity ratio data showed high accuracy and capability in modeling of thermal conductivity ratio data.

Corrosion and friction undulation caused by water-lubricated mechanical devices severely restricts the development of water-based lubricant in practical industries. In this paper, a kind of triazin...

The hydration and swelling of shale formations are serious problems for well drilling. The use of an efficient shale inhibitor is one of the most important methods for overcoming the wellbore insta...

The aim of the investigation was to observe the effect of administration methods of garlic on productivity of broiler chickens. Three hundred and forty unsexed one-day-old broiler chicks were reared for 35 days. Chicks were assigned into five treatment groups, each treatment consisted of four replicates and each replicate contained 17 birds. The dietary groups were; control (basal diet; no additives), antibiotic (basal diet + antibiotic), garlic-0.25% (basal diet + 0.25% garlic powder), garlic-0.50% (basal diet + 0.50% garlic powder) and garlic in water (basal diet + 1 colve of garlic/2 lit drinking water). The experimental diets were consisted of broiler starter (0-21 days) and broiler grower (22-35 days). Body weight, body weight gain, feed intake and feed conversion ratio of the birds were recorded every week. Results of this experiment indicate that supplementation of garlic in broiler diets significantly effect overall growth performances. Addition of garlic in water showed higher (P

International audience; Non-isocyanate polyurethane-ureas (NIPUUs) are a greener alternative to the traditional isocyanate-based polyurethane-ureas. These materials are synthesized by transurethanization and aminolysis of cyclic carbonate, commonly performed in solvents and in bulk. For several reasons including scalability, properties and environmental impact, there is a growing interest in developing water-based NPUUs. This review aims at discussing the achievements and the remaining challenges in the development of water-soluble NIPUUs, NIPUUs-based hydrogels as well as water-borne NIPUU dispersions.

Colloidal particles removal from water is a challenge in surface water treatment. Previously, we suggested an original technique for colloidal particles separation from water based on physical flow manipulation by an oscillating device. Laboratory experiments and 2D numerical simulation indicated that this technology enhances colloidal particles grouping and enables their rapid, simultaneous aggregation and sedimentation. The 2D model used in that study was unable to fully elucidate the grouping mechanism, settling pattern, or particle trajectories. Here, we extended the numerical simulation from 2D to 3D and examined the system’s distinctive flow field. The flow field was solved with computational fluid dynamics (CFD) simulations in the commercial ANSYS Fluent code and validated by dye injection experiments. The sedimentation patterns could nicely be explained by the computational results. This explanation was strengthened by two-dimensional population balance model simulations, which showed that particles aggregated in two zones trailing the paddle edges. Additionally, the results indicate significantly higher TKE values and faster upward vertical velocities at the higher oscillating frequency, which explains the different sedimentation patterns and removal efficiencies generated by the different oscillation frequencies. The use of 3D numerical simulations will help to better understand and further optimize this novel technology.

Compliant polishing (e.g. bonnet polishing) is widely used to finish freeform surfaces. However, direct pad/surface contact often causes scratches or embedding of abrasives, especially on metal moulds. Here, the use of non-Newtonian fluid (polymer and starch) to enable contactless polishing without need for a polishing pad is reported. Modelling and analysis are conducted to reveal the influence of fluid rheology on the material removal mechanism. Using #6000 grit alumina, Gaussian shaped removal footprints can be obtained, with a completely scratch-free roughness of 3.9 nm Ra on Nickel, in contrast with 70.3 nm Ra obtained by general water based bonnet polishing.

The phosphate content in water is crucial to all forms of life. Excessive phosphate in water can cause the excessive growth of algae and lower the oxygen content in water, which is a danger to our environment. However, most conventional methods for phosphate detection are time-consuming and instrument-dependent. In this work, three Cu-based metal–organic framework nanomaterials (Cu-MOF(1), Cu-MOF(2), Cu-MOF(3)) were synthesized. And it was found that the obtained three nanomaterials all exhibited peroxidase-like activities. Cu-MOF catalyzed color reaction can be inhibited in the presence of phosphate, and a colorimetric assay is constructed for the determination of phosphate by taking Cu-MOF(3) as an example. Good linearity existed between the absorbance of the Cu–MOF/TMB–H2O2 system at 652 nm and phosphate concentration from 0.05 μM to 5 μM, with the limit of detection down to 20 nM according to the S/N = 3 rule. Besides, the practicality of our assay was also certified by sensing PO43− in local river water samples.

Thermal-hydraulic characteristics of water based ZrO2 nanofluids has been investigated in a segmental baffled shell and tube heat exchanger in turbulent flow regime. The effect of Reynolds number, nanoparticle loading, mass-flow rate, and tube lay-out has been analysed on overall heat transfer coefficient. The effect of Reynolds number on the tube side pressure drop and convective heat coefficient have also been discussed. The effect of shell side mass-flow rate was also investigated on shell side heat transfer coefficient determined using Bell-Delaware method. The nanoparticle volume concentration is taken very low i. e. 0.2%, 0.4%, and 0.8%, respectively. The improvement in both tube side convective heat transfer coefficient and overall heat transfer coefficient has been observed. The maximum improvement in the convective heat transfer coefficient is found to be 14.1% for 0.8% ZrO2 nanofluids. However, the percentage enhancement in tube side pressure drop was higher than the percentage increment in the tube side heat transfer coefficient.

As a new type of carbon material, carbon dots (CDs) with exceptional properties are regarded as a type of potential water-based lubricant additive. In this study, it is first demonstrated that CDs perform excellently when used as lubricant additives for water-lubricated amorphous carbon (a-C) contacts. The results show that the introduction of CDs into water at a concentration of 0.1 wt% could reduce friction and wear in a-C contacts by 33% and 80%, respectively. Additionally, the lubricating performance of CDs is highly sensitive to its adding concentration. The excellent tribological performance of CDs results from the minimized CDs sediment particles (deposited in situ on worn a-C surfaces) and the reduced friction and wear via nano-bearing and nano-filling mechanisms. With high CDs concentrations, however, micron and submicron-sized sediment particles form when friction occurs and cause undesirable abrasive wear. For water-lubricated a-C contacts, therefore, the CDs concentration is the crucial determinant of lubrication performance that has to be appropriately controlled.

To reduce the environmental impact and improve the manufacturing productivity, many manufacturers are replacing the oil-based grinding fluids in their grinding processes with water-based ones. However, wholly oil-based grinding fluids are still used in superfinishing processes, in which the replacement is highly desired. To investigate the feasibility of the desired replacement, superfinishing experiments were conducted on hardened steels supplied with oil-based and water-based grinding fluids, and the superfinishing characteristics were investigated. Based on the findings, new water-based grinding fluids introducing ultrafine bubbles were developed. In superfinishing experiments, the machining performances of the developed fluids matched those of oil-based fluids.

Water-based liquid scintillators (WbLS) present an attractive target medium for large-scale detectors with the ability to enhance the separation of Cherenkov and scintillation signals from a single target. This work characterizes the scintillation properties of WbLS samples based on LAB/PPO liquid scintillator (LS). X-ray luminescence spectra, decay profiles, and relative light yields are measured for WbLS of varying LS concentration as well as for pure LS with a range of PPO concentrations up to 90 g/L. The scintillation properties of the WbLS are related to the precursor LAB/PPO: starting from 90 g/L PPO in LAB before synthesis, the resulting WbLS have spectroscopic properties that instead match 10 g/L PPO in LAB. This could indicate that the concentration of active PPO in the WbLS samples depends on their processing., 6 pages, 7 figures, 2 tables. Submitted to Materials Advances, a journal of the Royal Society of Chemistry

In present work, five different nanoparticles of three different shapes are used to study the enhancement in thermal conductivity, viscosity and stability of nanofluids. The main objective of present work is to analyze the effect of shape on thermo-physical properties of nanofluids. For this study, spherical, cubic and rod shaped nanoparticles are used. CuO, MgO, TiO2, ZrO2 and Al2O3 water based nanofluids are prepared by two step method using probe sonication technique. The effect of shape on thermal conductivity of nanofluids is analyzed experimentally by using hot-wire method set up. Results of this study reveal that the cubic shaped Al2O3 nanofluid (concentration 2.5 wt%) shows highest thermal conductivity over base fluid by 3.13 times. Effect of nanoparticle shape on the viscocity is also studied in the presnt work. Al2O3 nanofluid also has good stability amongst all nanofluids. Also, it is observed that in all five cases of nanofluid cubic shape nanoparticles enhance thermal conductivity at the highest rate than spherical and rod shape. Pumping power study shows that cubic shaped nanoparticles require higher pumping power than spherical and rod shaped nanoparticles.

Dynamic viscosity of SiO2/22nm nanofluids prepared in a glycerine-water (30:70 by volume) mixture base liquid, referred to as GW70, is measured experimentally. Nanofluids with concentrations of 0.2, 0.6, and 1.0 percent are produced, and viscosity measurements are carried out at temperatures ranging from 20 to 80 oC using a LVDV-2T model Brookfield Viscometer. The particle size and elemental composition of nanoparticles are determined using FESEM and EDX. XRD images confirm the SiO2 peaks in the crystalline structure. The rheology of nanofluids is influenced by the nanoparticle’s concentration. In the experimental temperature and concentration range, nanofluids show Newtonian behavior. The viscosity of nanofluids enhanced as particle concentration increased and reduced as temperature increased. For 1.0 percent vol. concentration at 20oC, the maximum viscosity value is achieved, and for 0.2 percent vol. concentration at 80oC, the lowest viscosity value is observed. The viscosity of the glycerine-water base fluid was also determined at 20, 40, 60, and 80 degrees Celsius. The viscosity ratio of nanofluids to the base liquid is found to be more than one for all the nanofluids. This viscosity data is useful to estimate HTC of glycerine-water-based silica nanofluids.

The efficiency of CO2 water-alternating-gas (WAG) flooding is highly limited in low-permeability heavy oil reservoirs due to the viscosifying action of W/O emulsification and high mobility contrast between oil and CO2. Here we propose a new enhanced oil recovery (EOR) process which involves water-based nanofluid-alternating-CO2 (NWAG) injection, and investigate the synergistic effect of nanofluid and CO2 for enhancing heavy oil recovery. Firstly, the oil-nanofluid and oil-water emulsions were prepared, and the bulk rheology and interfacial properties of emulsion fluid were tested. Then, core flooding tests were conducted to examine the NWAG flooding efficiency and its underlying mechanisms. The results showed that the bulk viscosity and viscoelasticity of oil-nanofluid emulsion reported much lower than those of oil-water emulsion, and nanofluid presented a positive contribution to the phase inversion from W/O to O/W emulsification. Compared with oil-water emulsion, the interfacial storage modulus of oil-nanofluid emulsion was obviously increased, which confirmed that more of crude oil heavy components with surface activity (e.g., resin and asphaltene) were adsorbed on interfacial film with the addition of silica nanoparticles (NPs). However, the interfacial viscosity of oil-nanofluid emulsion was much lower than that of oil-water emulsion, showing the irregularity of interfacial adsorption. This implied that the self-assembly structure of crude oil heavy component of the oil-water interface was destroyed due to the surface activity of silica NPs. During the core flooding experiments, NWAG injection could reduce the displacement pressure by 57.14% and increase oil recovery by 23.31% compared to WAG injection. By comparing produced-oil components after WAG and NWAG injection, we found that more of crude oil light components were extracted by CO2 during NWAG flooding, showing that the interaction between CO2 and crude oil was improved after oil-nanofluid emulsification. These findings clearly indicated two main EOR mechanisms of NWAG injection. One was the phase inversion during the nanofluid flooding process. The addition of silica NPs promoted phase-inversion emulsification and thus improved the displacement efficiency. The other was the enhanced interaction between CO2 and crude oil after oil-nanofluid emulsification. Because of the enhanced adsorption of crude oil heavy component on the oil-water interface, the proportion of light hydrocarbon increased in the bulk phase, and so the interaction between CO2 and oil phase was improved. This work could provide a new insight into the high-efficiency exploitation of low-permeability heavy oil reservoirs.

Radon is soluble in water, and the radon in drinking water is one of the sources of indoor radon. The China national standard for drinking water (GB5749-2006) indicates that the radon concentration in drinking water cannot be higher than 300pCi/L. The widely used method for measuring radon concentration in water is to use the RAD7 and the H2O accessory which provided by the Durridge Company for bubbling measurement. There are two kind sample bottles: 40ml and 250ml; the measurement steps: bubbling for 5 minutes, and measuring for 20 minutes. For the 40ml sample volume the conversion coefficient is around 25. For the 250ml sample volume the conversion coefficient is around 4. Since the price of the accessory is more than one thousand dollars, and the drying tube of the accessory is small, it needs to be replaced after each measurement which makes the operation is troublesome. We used a big drying tube to perform the radon concentration in water measurement. A new model for description the radon concentration in the gas circuit is proposed, and the conversion coefficient in any measurement condition is obtained. Any volume of sample bottle and drying tube can be used, selecting the suitable bubbling time and measuring time, the radon concentration in water can be obtained.

This work reports an alternative technique based on a complementary double split-ring resonator to determine the concentrations of ammonia and iron in water. The conventional methods for measuring ammonia and iron concentration involve expensive and bulky instruments in the laboratory. Furthermore, the current methods involve hazardous chemical reagents and complicated procedures. In this work, a low-cost microwave sensor which is portable and easy to operate is proposed. The water samples that have different ammonia or iron concentration is dropped deposited at the sensing area. Their concentration is determined based on the shifting of the resonance frequency in the measurement. The measurement results indicate that the resonance frequency of the resonator reduced from 2.38 GHz (unloaded condition) to a low-frequency range when the water sample containing different concentrations of ammonia or iron are introduced to the sensing area. Based on the collected results, Fourier models are used to establish the relationship between the concentrations of ammonia and iron (in the range of 0 to 53 mg/L) to the resonance frequency shifting. The validity of these models is proven as they introduced a root mean square error (RMSE) of less than 0.009. The findings of this work demonstrated the feasibility of the microwave sensor in detecting water pollutants.

During the oil and gas drilling engineering, the selection of drilling fluids must take account of the technical and environmental factors. This study investigated the effectiveness of carboxylated cellulose nanocrystals (denoted as CNCs) as environmentally friendly additives in improving the rheological, filtration, and inhibitive performances of bentonite (BT) water-based drilling fluids (WBDFs). CNCs used in this study were modified by carboxylation reaction, displaying small size, negative surface charge, good colloidal stability, and prominent shear thinning behavior. The experimental results indicated that BT/CNC suspensions had superior rheological properties, low fluid loss volumes, and effective inhibition, even at 140 °C. Microstructure analysis demonstrated that CNCs could attach to the surface of BT via hydrogen bond and ionic bond. CNCs, BT, and vicinal water molecules could form a stiff gel network, which had a strong resistance to flow under shear force, leading to a significant improvement in the rheological properties. Moreover, under the differential pressure, BT/CNC suspensions formed thin and less hydrophilic filter cakes with compact layered structure, thereby efficiently decreasing the fluid loss volume. Finally, due to the gel network and filtration ability, BT/CNC suspensions performed low water activity, which was beneficial for preventing the penetration of free water into the shales and borehole well. Thus CNCs also exerted satisfactory inhibition on hydration and dispersion of BT and shales. As a result, CNCs showed great potential to be used as efficient, multi-functional, and environmentally friendly additives in WBDFs.

BACKGROUND The aim of the present study was to investigate the muscular and cardiorespiratory adaptations of two water-based training programs in older women. METHODS Volunteers were divided between a water-based aerobic training (WBA; n=13), water-based combined training (WBC; n=11) or an active control group (CG; n=9) and those assigned to WBA and WBC exercised twice a week for 12 weeks. All outcomes of interest were assessed prior and after the intervention. The data were analyzed using Generalized Estimating Equations (GEE), and Bonferroni post-hoc test (α = 0.05). Aerobic training was performed at the percentage of the heart rate corresponding to the anaerobic threshold and resistance training during WBC was performed with sets at maximal effort. RESULTS Improvements were observed for the maximal knee extension dynamic strength (1RM) and oxygen uptake (VO2) corresponding to the second ventilatory threshold for both WBA and WBC (1RM: 16 ± 12% vs. 15 ± 16%; VO2: 20 ± 24% vs. 23 ± 13%, respectively), whereas VO2 peak improved in all three groups (WBA: 23 ± 21%; WBC: 18 ± 9%; CG: 7 ± 16%). No increase was found for horizontal chest press 1RM (p > 0.05). CONCLUSIONS These results suggest that WBA, WBC and CG are effective to improve cardiorespiratory fitness, however, only water-based training programs (WBA and WBC) appear capable of improving the maximal strength of the lower limbs.

The study assessed a new mobile electroencephalography (EEG) system with water-based electrodes for its applicability in time-frequency and event related potential research. It was compared to a standard gel-based wired system. EEG was recorded on two occasions as participants completed the flanker task, first with the gel-based system followed by the water-based system. Technical and practical considerations for the application of the new water-based system are reported based on the participant and experimenter experiences. Empirical comparisons focused on EEG data noise levels, frequency power across four bands including theta, alpha, low beta and high beta and P300 and ERN event related potential components. The water-based system registered more noise compared to the gel-based system which resulted in increased loss of data during artefact rejection. Signal to noise ratio was significantly lower for the water-based system in the parietal channels which impacted the observed parietal beta power. It also led to a shift in topography of the maximal P300 activity from parietal to frontal regions. It is also evident, that the water-based system may be prone to slow drift noise which may affect the reliability and consistency of low frequency band analyses. Considerations for the use of this specific system for time-frequency and event related potentials are discussed.

We report the use of benign and green precursors, including waste chicken eggshells and PET (polyethyleneterephthalate) from recycled plastic bottles, for the facile synthesis of a variety of calcium-based metal-organic frameworks (Ca-MOFs), using water based and mechanochemical synthesis techniques.

Applying nanomaterials and nanotechnology in lubrication has become increasingly popular and important to further reduce the friction and wear in engineering applications. To achieve green manufacturing and its sustainable development, water-based nanolubricants are emerging as promising alternatives to the traditional oil-containing lubricants that inevitably pose environmental issues when burnt and discharged. This review presents an overview of recent advances in water-based nanolubricants, starting from the preparation of the lubricants using different types of nanoadditives, followed by the techniques to evaluate and enhance their dispersion stability, and the commonly used tribo-testing methods. The lubrication mechanisms and models are discussed with special attention given to the roles of the nanoadditives. Finally, the applications of water-based nanolubricants in metal rolling are summarised, and the outlook for future research directions is proposed.

A complete overview of the rheology and filtration properties of drilling fluids is essential to ensure an efficient transport process with minimized fluid loss. Silica nanoparticle is an excellent additive for rheology and filtration properties enhancement. Existing correlations are not available for nano-SiO2-water-based drilling fluid that can extensively quantify the rheology or filtration loss of nanofluids. Thus, two data-driven machine learning approaches are proposed for prediction, i.e., artificial neural network (ANN) and least square support vector machine (LSSVM). Parameters involved in the prediction of shear stress are SiO2 concentration, temperature, and shear rate, whereas SiO2 nanoparticle concentration, temperature, and time are the inputs to simulate filtration volume. A feed-forward multilayer perceptron is constructed and optimized using the Levenberg–Marquardt learning algorithm. The parameters for the LSSVM are optimized using couple simulated annealing (CSA). The performance of each model is evaluated based on several statistical parameters. The predicted results achieved R2 (coefficient of determination) value higher than 0.99 and mean absolute error (MAE) and mean absolute percentage error (MAPE) value below 7% for both the models. The developed models are further validated with experimental data that reveals an excellent agreement between predicted and experimental data.