Basic Fluids Research Articles

“Enhancing heat transfer in high-pressure transformers: A study on nanoparticle-doped insulating fluids”

The impact of doping electrical insulating fluids with nanoparticles on the thermal characteristics of the resulting nanofluids and heat transfer for cooling high-power transformers is covered in this study. The base fluid in this case was the synthetic ester. It investigated how adding Barium titanate (BaTiO3)nanoparticles to dielectric fluids affected thermal characteristics, including convection and thermal conductivity. Comparisons were made between the cooling performance of basic fluids and nanofluids. An examination of the Rayleigh and Nusselt values confirms this comparison. The effects were represented as functions of the solid volume particle from the nanoparticles (0 ≤ φ < 10 %) and the thermal Rayleigh number (Rat = 103 and 106). The findings demonstrate that increasing the solid particle size of nanoparticles by 10 % increases the employed liquid's effectiveness as a conductor and raises the heat transfer rate by about 10 % compared to the base liquid.

Performance evaluation of solar still using evacuated tube collector with and without nanoparticles.

Solar-thermal distillation is recognized as a low-cost, long-term technique of producing high-quality fresh water in the lack of energy and clean water infrastructure. Improvements to distillation have lately been developed by the application of three main phases depending on the transition of sunlight into heat energy, the generation of thermal vapor, and the condensation of vapor into water. The effectiveness of collected distillation water from evacuated tube collectors on nanoparticles was examined along with basic fluids including water and copper oxide, aluminum oxide, and zinc oxide. Additionally, an investigation of the relationship between specific heat and thermal conductivity, as well as between actual and theoretical heat generation, was conducted. For 11 h of operation, 2275 ml of distilled water was collected using evacuated tube collectors without nanoparticles. The efficiency of the nanoparticles compared to water was more than 17.4% CuO, 15.7% Al2O3, and 14.5% ZnO improved and an increase in overall efficiency of 66.6%. As a result of the experiment, the greatest actual heat generation, expressed in kilowatt-hour, exceeds the theoretical value.

The Heat Transfer Coefficient in a Copper Pipe Flow System Using a 40/60 Volume Ratio Ethylene Glycol/Water (EG/H2O) Blended Fluid

This study discusses the performance of Ethaline Glycol/water (EG/H2O) fluids at a volume ratio of 40/60. EG/H2O fluids are widely used as basic fluids in cooling and heating system applications. The discussion of EG/H2O fluid performance is focused on the analysis of the heat transfer coefficient and pressure drop. The study used an experimental method using a suction test made of pure copper with an inner diameter, outer diameter and length of 16 mm, 19 mm and 1500 mm respectively. The EG/H2O volume ratio at 40/60 was selected as the input parameter. Other input parameters are variations in the fluid flow rate which are regulated using a control valve at fluid flow rates of 4, 6, 8, 10.12, 14.16 and 18 liters/minute. A 2-unit tubular heater with a total capacity of 2000 W was installed on the sides of the copper pipes. A voltage regulator with a capacity of 3000 W is used to regulate the electric power by regulating the supplied voltage. Ampere pliers are used to measure amperage at the setting used. The experimental results show that the performance of the EG/H2O fluid on the heat transfer coefficient increases as the fluid flow rate increases. The highest heat transfer coefficient rate was obtained at a fluid flow rate of 18 L/minute, while the lowest value was obtained at a fluid flow rate of 4 L/minute. Pressure drops fluctuations occur as the fluid flow rate increases. Even though there is a fluctuating pressure drop, this condition does not significantly affect the friction factor, because the fluid flow characteristics occur in a turbulent manner

Entropy Production Analysis in an Octagonal Cavity with an Inner Cold Cylinder: A Thermodynamic Aspect

Understanding fluid dynamics and heat transfer is crucial for designing and improving various engineering systems. This study examines the heat transfer characteristics of a buoyancy-driven natural convection flow that is laminar and incompressible. The investigation also considers entropy generation (Egen) within an octagonal cavity subject to a cold cylinder inside the cavity. The dimensionless version of the governing equations and their corresponding boundary conditions have been solved numerically using the finite element method, employing triangular mesh elements for discretization. The findings indicated that incorporating a cold cylinder inside the octagonal cavity resulted in a higher heat transfer (HT) rate than in the absence of a cold cylinder. Furthermore, using the heat flux condition led to a higher average Nusselt number (Nuavg) and a lower Bejan number (Be) than the isothermal boundary condition. The results also showed that HT and Egen were more significant in the Al2O3-H2O nanofluid than the basic fluids such as air and water, and HT increased as χ increased. The current research demonstrates that employing the heat flux condition and incorporating nanoparticles can enhance the rate of HT and Egen. Furthermore, the thermo-fluid system should be operated at low Ra to achieve greater HT effectiveness for nanofluid concerns.

MENTAL AND BEHAVIOURAL DISORDERS IN “THE PROPOSAL” BY ANTON CHEKHOV

Based on the comparative approach, narrative medicine and pathology diagnostics, the article examines the personal psychological deviations of the characters in Anton Chekhov. The article reveals the main stages in the diagnosis and the interpretation of hypochondria, melancholy, timidity from antiquity, where pathological features of personality and types of temperament were associated with the balance of the elements and basic fluids in the human body, to the Enlightenment and the modernity, where personal pathologies were dictated by mental predisposition and social environment. Molière’s main goal is to identify the type of “imaginary patient” as an expression of hypochondria symptom and to ridicule the type of a quack doctor, while for Chekhov («Proposal»), the main character’s hypochondria is complicated by timidity and procrastination, designed to enhance the comic effect of the described situation. This allows us to consider in a new way the difference between the typological approach to the human being as a combination of passions in the classical comedy and in the mature realism of the 19th century. The conclusion is made about the importance of a literary typological study of psychological deviations and pathologies in the history of human civilisation and intellectual culture.

Entropy Generation of CuO-Water Nanofluid in a Cavity with an Intruded Rectangular Fin

Entropy generation and heat transfer in cavities have received significant interest due to the ever-increasing demand for enhancing thermal performances in many scientific and engineering fields. In particular, nanofluids are being used increasingly in engineering applications and real-life problems, as they exhibit significantly better thermal properties than basic heat transfer fluids, for example, water, oil, or ethylene glycol. This study investigates the entropy generation and heat transfer of a nanofluid in a confined cavity with a moving top wall and a rectangular fin at the bottom. Here, a macro-homogeneous model based on a previously developed model is employed for investigating the mixed convective flow and heat transfer of CuO-water nanofluid. Various fin geometries, Rayleigh numbers, Reynolds numbers, and nanofluid concentrations have been employed. Present results indicate that the heat transfer rate can be improved, while entropy generation can be minimized using nanofluids instead of conventional heat transfer fluids.

Synthesis and Characterization of TiO2-Water Nanofluids

Nanofluids made of TiO2 and multiwalled carbon nanotubes are the focus of our study. Using TiO2 and water as the basic fluids, nanofluids were created in 100 : 0, 75 : 25, and 50 : 50 proportions. Carbon nanotubes (CNTs) were disseminated into these base fluids of three types at 0.125, 0.25, and 0.5 percentages. Over the course of two months, the change of zeta potential is monitored to assess the stability of the dispersion. XRD analysis and SEM and TEM analysis are carried out for TiO2 nanofluids. Nanoparticles were analyzed using EDAX analysis to identify their composition. SEM examination was used to investigate the morphology for TiO2 nanoparticles. Particles of TiO2 produced in this manner seemed to have an average diameter of 27 nm. Nanofluids have a poor stability, which is the most important aspect of employing them, although most studies did not focus on this. When it comes to nanofluids, this study is unique in that it provides an in-depth look of surface modification approaches that have been employed by researchers to address these issues, as well as an evaluation of their stability over two months. Solubility is improved by acid treatment of CNTs, which results in functional groups on the surface of CNTs.

Evaluation of Physicothermal Properties of Solar Thermic Fluids Dispersed with Multiwalled Carbon Nanotubes and Prediction of Data Using Artificial Neural Networks

A review of multiwalled carbon nanotubes as solar thermic fluids and their thermophysical properties is done in this article. The basic fluids were ethylene glycol and water in ratios of 100 : 0, 90 : 10, and 80 : 20. To investigate how surface modification impacts thermophysical properties, three base fluids were combined with surfactant-assisted MWCNTs and oxidized MWCNTs in weight fractions of 0.125, 0.25, and 0.5 percent, respectively. It takes two months to check whether the dispersion stays constant. Thermal conductivity and viscosity measurement were done using heated discs and Anton Paar viscometers. Using oxidized MWCNTs to disperse, the base fluids increased thermal conductivity by 15% to 24%. Surfactant-assisted MWCNTs in nanofluids perform worse than oxidized MWCNTs. The dynamic viscosity of nanofluids is higher than that of basic fluids between 50 and 70°C. During a mathematical computation, all of the MWCNT weight fractions and ethylene glycol volume percentages are included. The correlation may be a good fit for the experimental data within limits. The characteristics are forecasted using feed-forward backpropagation. In this research, buried layer neurons and factors are examined.

Synthesis of Al(OH)3 nanoparticles from Indonesian bauxite and tomato waste extract as chelating agent for nanofluids applications

This study aimed to determine the effect of calcination time on the properties of Al(OH)3 or gibbsite nanoparticles in the sol-gel process, which was then used as the basic material in the manufacturing of water-Al(OH)3 based nanofluids. Nanofluid is a mixture of basic fluids such as water with solid nanoparticles. Al(OH)3 nanoparticles have been successfully synthesized from Indonesia local mineral bauxite using the sol-gel method by utilizing tomato waste extract as a chelating agent at a calcination temperature of 700ºC for 1 hour, 3 hours, and 5 hours. The obtained calcined powders were characterized using X-ray diffractometer (XRD). The evaluation toward nanofluids application based on theirs stability based on visual observation and zeta potential. Based on XRD analysis, all calcined powders has single Al(OH)3 or gibbsite phase. Increasing the calcined temperature gave impact on crystallinity, crystallite size, and reorientation of crystal. The water-Al(OH)3 nanofluid was relatively less stable with a zeta potential value of -25.2 mV; -26.4 mV; and -17.4 mV for calcination time 1 h, 3 h, and 5 h, respectively.

Effect of viscosity on heat transfer in nanoparticles

In our research, it has been concluded that there are various utilizing areas for Nano-fluids in industrial fields in solar energy systems and even thermal systems. The demotion of the particles in Nano-fluids as nonmetric size should vary between one to one hundred nanometers in the basic fluids. In this work, Nano-fluids usage in cooling or chilling and even heating and their usage districts were explored. Due to the researches, we identified that thermal conductivity’s efficiency affects of the differences of the Nano-fluids with different aspects.

State of the Art in PEG-Based Heat Transfer Fluids and Their Suspensions with Nanoparticles.

Research on nanoparticle enhanced fluids has increased rapidly over the last decade. Regardless of several unreliable reports, these new fluids have established performance in heat transfer. Lately, polyethylene glycol with nanoparticles has been demarcated as an innovative class of phase change materials with conceivable uses in the area of convective heat transfer. The amplified thermal conductivity of these nanoparticle enhanced phase change materials (PCMs) over the basic fluids (e.g., polyethylene glycol—PEG) is considered one of the driving factors for their improved performance in heat transfer. Most of the research, however, is centered on the thermal conductivity discussion and less on viscosity variation, while specific heat capacity seems to be fully ignored. This short review abridges most of the recent investigations on new PEG-based fluids and is dedicated especially to thermophysical properties of the chemicals, while a number of PEG-based nanofluids are compared in terms of base fluid and/or nanoparticle type and concentration. This review outlines the possibility of developing promising new heat transfer fluids. To conclude, this research is in its pioneering phase, and a large amount of experimental and numerical work is required in the coming years.

Strength analysis of geopolymer concrete based on fly ash and P-sand

The genuine emergency of the world is confining today for trending of natural causes the ecological contamination. In the development business principally the creation of OPC will causes the discharge of toxins brings about ecological contamination. We can cut down the contamination impact on climate, by broadening the utilization of modern outgrowth in our development industry. Geopolymer concrete is the current study, to create the geo-polymer concrete. The Portland concrete is completely replace with fly debris and the fine total is replaced with p-sand and basic fluids can be utilized for the limiting of materials. The antacid fluids utilized in this assessment for the polymerization are the arrangements of Sodium hydroxide (NaOH) and sodium silicate (Na2Sio3). Various molarities of sodium hydroxide arrangement for example 8 M, 10 M and 12 M are taken to get ready distinctive mix. Also, the compressive strength is determined in the structural lab. The solid shape examples are taken of size 150 mm × 150 mm × 150 mm and the 1 m3 3D square. The geopolymer concrete specimens are tried for their compressive strength at the period of 21 days, mixes of different sodium hydroxide molarities i.e.8 M, 10 M and 12 M are readied and they are cured by direct daylight and their strengths are determined for 21 days. The outcome shows that the strength of geopolymer concrete rises with the expansion of the molar concentration of sodium hydroxide.

In-House Production of Dialysis Solutions to Overcome Challenges During the Coronavirus Disease 2019 Pandemic

In-House Production of Dialysis Solutions to Overcome Challenges During the Coronavirus Disease 2019 Pandemic

Thermal conductivity of nanofluids based on hollow γ-Al2O3 nanoparticles, and the influence of interfacial thermal resistance

The current paper presents the results of theoretical and experimental studies of the thermal conductivity of nanofluids based on hollow nanoparticles. The thermal conductivity of nanofluids was studied experimentally using hollow Al2O3 nanoparticles in water, ethylene glycol, and isopropyl alcohol. The experiments were carried out at nanoparticle volume concentrations of 2.2%. Thermal conductivity was measured by the nonstationary hot wire method. It was found that the dependences of thermal conductivity obtained on volume concentration gave values below those obtained by the Maxwell theory for all nanofluids. The analysis showed that the presence of a cavity under the conditions of these experiments could not explain the observed results. The conclusion about the final value of Kapitza contact resistance at the nanoparticle-liquid interface was made based on the comparison of experimental data with the theory. The Kapitza contact resistances were estimated for the interfaces between nanoparticle material and basic fluids used.

Characterization of Paleogene hydrothermal events and their effects on reservoir properties in the Qikou Sag, eastern China

Widespread igneous activities occurred in the Qikou Sag, eastern China since the Paleogene with numerous dikes and sills preserved in the sedimentary sequence. Based on an integrated petrographic, fluid inclusion and organic geochemistry investigation, we have documented these hydrothermal fluid events and the effects of the associated thermal fluids on the reservoir properties. The Paleogene volcanic rocks in the Qikou Sag consist mainly of a set of basalt-diabase series of basic volcanic and intrusive rocks. Strong thermal anomalies caused by the hydrothermal fluid flows are present in the Qikou Sag, as evidenced from hydrothermal alteration of the sediments and abnormal depth profiles of vitrinite reflectance values (Ro), Rock-Eval pyrolysis parameters (e.g. Tmax, S1 and S2), fluid-inclusion homogenization-temperatures (Th) and clay-mineral transformations.An abrupt increase in Ro observed in the deep strata of the Qikou Sag is interpreted to be mainly caused by deep-sourced thermal fluids. Magmatic thermal fluids associated with intrusions and deep-sourced thermal fluids had caused different impacts on the transformation of the mixed-layer I/S clays: the magmatic thermal fluids affected the transformation of the clays by causing a potassium-deficient fluid environment after the emplacement of the intrusions, whereas the deep-sourced thermal fluids only provided a heat source. The shallow (<3500m) basic magmatic CO2-rich hydrothermal fluids have significantly enhanced the reservoir porosity and permeability, although the effect is only limited to the surrounding area of about five times of the intrusion body thickness. In contrast, the deep CO2-rich thermal fluids (>3500m) appear to have a sustained effect and exert a much broader thermal impact on the reservoirs due to their continuous nature and prolonged activity.

Solubility and fluid–melt partitioning of H2O and Cl in andesitic magmas as a function of pressure between 50 and 500 MPa

This study presents experimental data on the partitioning of Cl between andesitic melt and H2O- and Cl-bearing fluids at 1200°C and at 50 to 500MPa. The results demonstrate that at isothermal conditions Cl partitioning is governed by pressure, Cl and H2O content in the system affecting mixing properties of the fluid phase. The maximum Cl contents in the melt reach ~2.5wt.% Cl at P<200MPa and about 3–3.5wt.% Cl at P>300MPa in a good agreement with recent model (Webster et al., 2015. Experimental and modeled chlorine solubilities in aluminosilicate melts at 1 to 7000bars and 700 to 1250°C: Applications to magmas of Augustine Volcano, Alaska. Am. Mineralogist, 100: 522–535). Water solubility in the melt increases from 1.4 to 10wt.% with pressure increase from 50 to 500MPa and can be described by a power law: H2O (wt%)=0.0659·P0.8184 (R2=0.98). Moreover, there is a positive correlation between water and Cl contents of the melt at P<200MPa with an increase of maximum water concentration by a factor of 2 at 50MPa in the range 0 to ~2wt.% Cl. Both increasing pressure and increasing Cl content in the system enhance partial dissolution of the melt into the fluid (mainly by extraction of Ca, Na and K) resulting in large uncertainty of fluid composition determination. However, based on well-defined systematic trends and observed general relationships between Cl+cation+H2O contents in the melt and fluid phases, the systems at P<200MPa can be characterized by the occurrence of fluid immiscibility (vapor+brine), whereas at P>300MPa a single supercritical fluid is considered. Surprisingly, vapor phase at P<200MPa can contain up to 35–40wt.% Cl+Σcations indicating that the immiscibility gap in andesitic system is dramatically reduced when compared with that of simple water–salt fluids or silicic melt+fluid systems. Despite observed differences in fluid characteristics at low and high P, fluid–melt partition coefficients of Cl (DCl) show similar non-linear evolution as a function of Cl content in the melt up to 2wt.% and vary between ~1 and ~12 (on mass basis). Furthermore, systems with Cl content in the melt <1wt.% follow Henrian behavior and considering only reproducibility errors for this range, their averaged DCl values demonstrate a pronounced minimum at around 2 at 200MPa. A negative pressure dependence of DCl between 50 and 200MPa can be described by a power law DCl=279.92·P−0.914 (R2=0.95), whereas a positive correlation with P between 200 and 500MPa can be fitted by an exponential function: DCl=1.0444·e0.004·P (R2=0.97). The observed change in the DCl trend is presumably attributed to the changes in Cl speciation in the fluid, i.e., from acidic HCl-dominated fluids at low P to basic cation-dominated fluids at high P which might be also responsible for the significant decrease in the fluid immiscibility gap at P<200MPa. The compilation of experimental data on Cl partitioning illustrates that silicic peralkaline magmas typically have up to an order of magnitude higher DCl at P>200MPa but may have comparable DCl at P<200MPa than the DCl of more mafic and metaluminous magmas.

The transformation of nepheline and albite into sodalite in pegmatitic mariupolite of the Oktiabrski Massif (SE Ukraine)

Sodalite, Na8Al6Si6Cl2, from a pegmatitic variety of mariupolite in the Oktiabrski Massif (SE Ukraine) was studied using electron microprobe, electron microscopy, spectroscopic cathodoluminescence and Raman techniques to determine its growth history during the evolution of the host rock. Three generations of the mineral were distinguished: (1) the oldest forms patches with a pink-violet cathodoluminescence colour, (2) a younger one, with a dark blue colour, forms the matrix of the crystals, and (3) the youngest generation forms veins with light blue cathodoluminescence in the older sodalite generations; all are undoubtedly secondary phases formed during the post-magmatic evolution of the host rock. The close spatial association of the sodalite with coexisting albite, nepheline, natrolite and K-feldspar, forming inclusions in each other, and the embayed contacts of sodalite with nepheline and albite, and the patchy appearance of sodalite under CL, together suggest that the two older sodalite varieties formed from the conversion of nepheline and albite under the action of Na-, Cl- and Al-bearing, but Si undersaturated basic fluids released during cooling of the host. The excess of SiO2 (aq.) released as a result of albite metasomatism could be accommodated by natrolite occurring as tiny inclusions within the sodalite crystals. The youngest, veinlet, generation was probably formed via a fluid-mediated dissolution–recrystallization process, perhaps simultaneously with the coexisting veins of natrolite.

The Influence of Basic Volcanic Fluids on Gaseous Products of Source Rocks

The aspects, such as composition, temperature, viscosity, and fluidity, of basic volcanic fluids are greatly different from acidic volcanic fluids. In order to further complement the conceptual model of the influence of volcanic fluids on source rocks in petroliferous basins, this research uses the thermal simulation experiment to analyze the characteristics and reasons of the ratio of alkanes to acid, dry coefficient, and carbon isotope in the dry and fluid systems. The results show that, the ratio of alkanes to acid of all samples in the two systems will increase with the rise of temperature and presents features of the dry system higher than the fluid system, which indicates that the basic volcanic fluids restrain the generation of gaseous hydrocarbons. The dry coefficient of the fluid system at the range of 300–400°C is greater than that of the dry system, while smaller at the range of 400–450°C, which indicates that the basic volcanic fluids promote the generation of CH4 in low temperature. In the two systems, δ13CO2 of all samples have no obvious change as the rising of temperature, but in the fluid system the proportion of carbon isotopic will increase with the rising of temperature, which shows that carbonate exists in the volcanic fluids. The carbon isotopes of gaseous hydrocarbon in three samples are presented as δ13C1 < δ13C2 < δ13C3, and it accords to general pyrolysis regularity without reversal phenomenon, which indicates alkane gases produced by pyrolysis of three samples are of organic origin.

Characteristics of ethoxylated fatty amine emulsion: Effects on the wettability and permeability of silicate formation under various pH conditions

Abstract The effects of ethoxylated fatty amine emulsion on the wettability and permeability of silicate rock under various pH conditions, as well as the adsorption behavior of ethoxylated fatty amine on the silicate rock surface, were investigated using core displacement test, contact angle test and infrared spectroscopy. A new knowledge about the characteristic and mechanism of formation damage from reversible invert emulsion drilling fluids and a new method for the completion and cementing of a well drilled by reversible invert emulsion drilling fluids were proposed. Under pH of 4 to 8, exthoxylated fatty amine can adsorb on the rock surface to various degrees, resulting in the strong oil-wet condition of rock which does a serious harm to the permeability of the formation. Under pH of 10, no exthoxylated fatty amine adsorbs in the rock, resulting in the water-wet condition of the rock surface which is benefit to mitigating the damage of mud to the permeability of the formation. It is suggested removing the reversible invert emulsion drilling fluid using acidic fluids followed by basic fluids or using acidic fluids combined with wettability alteration agents.

Insights from X-ray absorption/fluorescence spectroscopy and ab-initio molecular dynamics on concentration and complexa-tion of Zr and Hf in aqueous fluids at high pressure and temperature

High-field-strength elements such as Zr and Hf are important geochemical indicators for processes in the deep Earth. Aqueous fluids play a significant role in the transport of heat and matter in these systems. However, concentrations and complexation of Zr and Hf in these fluids at high pressure (P) and temperature (T) conditions are largely unknown. Zr/Hf contents were determined in-situ at P and T in aqueous fluids containing NaOH, HCl or Na-Al silicate components in equilibrium with zircon or baddeleyite. Concentrations are strongly enhanced in comparison to pure H2O. The variation of Zr/Hf contents with fluid composition and their respective variation with P and T point to differences in the Zr/Hf complexation. High-resolution Zr K-edge XANES spectra were collected in-situ at P and T as well as Hf L3-edge XANES spectra. Analysis of spectra evidences considerable differences in the coordination of Zr and Hf as a function of fluid composition. [7]Zr is found in NaOH solution. [7]Zr is also found in HCl solution, however, coordinated by both chlorine and oxygen. In fluids with Na-silicate components, Zr and Hf are 6-fold coordinated in zircono-silicate complexes, likely complexed with Na and Si. Further insight into the speciation was obtained by ab-initio molecular dynamics simulations of Zr monomers in H2O-NaOH and H2O-HCl. In basic solutions, Zr is five-fold coordinated by oxygen, whereas in acidic solutions, mixed oxychloride complexes are formed. The oxychloride complexes also seem to be present in experimental fluids, whereas the Zr coordination in basic fluids is underestimated by the simulations. The most likely explanation for this discrepancy is the formation of Zr oligomers in the fluid.