Significance of Nanoparticles Aggregation with Cattaneo-Christov Heat Flux on the Water and Ethylene Glycol Mixture Based MWCNTs-Nanofluid Flow over a Stretching Cylinder

This work aims to analyze the flow of electrically conducting MWCNTs-nanofluid over a stretching cylinder with the aggregation and non-aggregation effects of nanoparticles. The working fluid comprised a combination of water and ethylene glycol, with volumetric proportions of (50:50) considered. Convective boundary constraints and modified Fourier law are implemented in heat transmission assessment. The mathematical flow model is formulated in the form of PDEs and is transformed into ODEs via similarity transformation. Numerical outcomes will be obtained with the use of the bvp4c technique and will be displayed with the help of graphs and tables. The results show that the surface drag coefficient is enhanced in the case of aggregation of nanoparticles whereas heat transfer rate is enhanced in the non-aggregation effect of nanoparticles. Furthermore, the temperature distribution enhances the increasing values of particle volume fraction in the case of aggregation effects of nanoparticles whereas temperature distribution lowers in the case of non-aggregation effect of nanoparticles. .

Absorption and Structural Property of Ethanol/Water Mixture with Carbon Nanotubes

Molecular dynamics （MD） simulations are performed to study the structure and adsorption of ethanol/water mixture within carbon nanotubes （CNTs）. Inside the （6,6） and （10,10） CNTs, there are always almost full of ethanol molecules and hardly water molecules. Inside wider CNTs, there are some water molecules, while the ethanol mass fractions inside the CNTs are still much higher than the corresponding bulk values. A series of structural analysis for the molecules inside and outside the CNTs are performed, including the distributions of radial, axial, angular density, orientation, and the number of hydrogen bonds. The angular density distribution of the molecules in the first solvation shell outside the CNTs indicates that the methyl groups of ethanol molecules have the strongest interaction with the carbon wall, and are pinned to the centers of the hexagons of the CNTs. Based on the understanding of the microscopic mechanism of these phenomena, we propose that the CNTs prefer to contain ethanol rather than methanol.

SELECTIVE SEPARATION OF WATER-ETHANOL MIXTURES THROUGH COPOLYMERIC MEMBRANES: Ⅰ. ACRYLIC ACID AND ACRYLONITRILE COPOLYMER AND ITS IONIZED MEMBRANES

The copolymer of acrylic acid and acrylonitrile has been synthesized and pervaporation properties of the copolymeric membranes have been investigated. In order to elucidate the influence of membrane-permeate interaction on the pervaporation of water-ethanol mixtures and to prepare much improved membranes, the membranes have been treated with alkali metal, alkali earth metal and transition metal salt aqueous solutions. The treated membranes (ionized membranes) exhibited higher separation factors than the untreated membranes. The separation factors of various alkali metal cation membranes decreased in the following order : Li^+>Na^+>K^+, and the permeation rates showed an opposite tendency. The dependence of pervaporation behavior on the copolymer composition ,feed concentration and operating temperature have been studied with both ionized and non-ionized membranes. The apparent activation energies of water and ethanol permeation were calculated.

Recent advances in Ni-based catalysts for the electrochemical oxidation of ethanol

The electrochemical ethanol oxidation reaction(EOR) plays a crucial role in electrochemical hydrogen production and direct ethanol fuel cells, both vital for utilizing renewable energies. Ni-based catalysts are pivotal in enabling efficient EOR, leading to the formation of acetic acid/acetaldehyde or CO_(2). These can serve as alternative anodic oxidation reactions for oxygen evolution reaction(OER) in water electrolysis or the anodic reaction for direct ethanol fuel cells, respectively. This review explores recent advancements in EOR over Ni-based catalysts. It begins with an overview of EOR performance across various Ni-based catalysts, followed by an examination of the reaction chemistry, mechanism, and active sites.The review then delves into strategies for designing highly active Ni-based EOR catalysts. These strategies include promotion with transition metals, noble metals, nonmetals, and carbon materials, as well as creating amorphous structures, special morphologies, and single-atom catalysts. Additionally, it discusses the concept of self-supporting catalysts using three-dimensional porous substrates. Finally, the review highlights emerging methodologies that warrant further exploration, along with future directions for designing highly active and stable EOR catalysts.

Rational modulation of electronic structure in PtAuCuNi alloys boosts efficient electrocatalytic ethanol oxidation assisted with energy-saving hydrogen evolution

Compared to conventional electrocatalytic water splitting,electrocatalytic ethanol oxidation reaction(EOR)along with hydrogen production is considered a more energy-efficient strategy.Herein,we prepared a type of novel quaternary alloy catalyst(PtAuCuNi@NF)that exhibits excellent activity for EOR(0.215 V at 10 mA cm^(-2))and hydrogen evolution reaction(HER)(7 mV at 10 mA cm^(-2)).Experimental results demonstrated that both Cu and Ni modulated the electronic environment around Pt and Au.The electron-rich active center facilitates the rapid adsorption and dissociation of reactants and intermediates for both EOR and HER.Impressively,in the ethanol-assisted overall water splitting(E-OWS),a current density of 10 mA cm^(-2)was achieved at 0.28 V.Moreover,an advanced acid-base self-powered system(A-Bsps)that can achieve a self-powered voltage of 0.59 V was assembled.Accordingly,the self-driven hydrogen production with zero external power supply was realized by integrating A-Bsps with the E-OWS equipment.The interesting results can provide a feasible strategy for designing and developing advanced nanoalloy-based materials for clean energy integration and use in various fields.

Influence of water vapor on the separation of volatile organic compound/nitrogen mixture by polydimethylsiloxane membrane

In the industrial treatment of waste volatile organic compound(VOC)streams by membrane technology,a third impurity,generally,water vapor,coexists in the mixture of VOC and nitrogen or air,and can affect membrane performance and the design of the industrial process.This study focused on the investigation of the effect of water vapor on the separation performance of the separation of VOC/water/nitrogen mixtures by a polydimethylsiloxane(PDMS)membrane.Three types of VOCs:water-miscible ethanol,water-semi-miscible butanol,and water-immiscible cyclohexane,were selected for the study.Different operating parameters including,concentration of the feed VOC,feed temperature,and concentration of the feed water were compared for the separation of binary and ternary VOC/nitrogen mixtures.The interaction between the VOC and water was analyzed to explain the transportation mechanism after analyzing the difference in the membrane performance for the separation of binary and ternary mixtures.The results indicated that the interaction between the VOC(or nitrogen)and water is the key factor affecting membrane performance.Water can promote the permeation of hydrophilic VOC but prevent hydrophobic VOC through the membrane for the separation of ternary VOC/water/nitrogen mixtures.These results will provide fundamental insights for the design of the recovery application process for industrial membrane-based VOCs,and also guidance for the investigation of the separation mechanism in vapor permeation.

A spectral mixture model analysis of the Kuroshio variability and the water exchange between the Kuroshio and the East China Sea

For understanding more about the water exchange between the Kuroshio and the East China Sea,We studied the variability of the Kuroshio in the East China Sea(ECS) in the period of 1991 to 2008 using a three-dimensional circulation model,and calculated Kuroshio onshore volume transport in the ECS at the minimum of 0.48 Sv(1 Sv ;106 m3/s) in summer and the maximum of 1.69 Sv in winter.Based on the data of WOA05 and NCEP,The modeled result indicates that the Kuroshio transport east of Taiwan Island decreased since 2000.Lateral movements tended to be stronger at two ends of the Kuroshio in the ECS than that of the middle segment.In addition,we applied a spectral mixture model(SMM) to determine the exchange zone between the Kuroshio and the shelf water of the ECS.The result reveals a significantly negative correlation(coefficient of-0.78) between the area of exchange zone and the Kuroshio onshore transport at 200 m isobath in the ECS.This conclusion brings a new view for the water exchange between the Kuroshio and the East China Sea.Additional to annual and semi-annual signals,intra-seasonal signal of probably the Pacific origin may trigger the events of Kuroshio intrusion and exchange in the ECS.

Experimental study on the flow behaviour of water-sand mixtures in fractured rock specimens

The study of flow behaviour of water-sand mixtures in fractured rocks is of great necessity to understand the producing mechanism and prevention of water inrush and sand gushing accidents.A self-developed seepage test system is used in this paper to conduct laboratory experiments in order to study the influence of the particle size distribution,the void ratio,and the initial mass of Aeolian sand on the flow behavior.It is concluded that the water flow velocity is insensitive to the initial mass of the Aeolian sand but increases with the power exponent in the Talbot formula and the specimen height.The outflow of the Aeolian sand increases with the power exponent in the Talbot formula,the specimen height,and the initial mass of the Aeolian sand.Besides,the outflow of the Aeolian sand changes exponentially with the water flow velocity.Finally,it is found that the fractured specimen has a maximum sand filtration capacity beyond which the outflow of the Aeolian sand significantly increases with the initial mass of the Aeolian sand.

Molecular simulation of penetration separation for ethanol/water mixtures using two-dimensional nanoweb graphynes

Graphyne is expected to be a new-class of highly-efficient sieving membranes due to its controllable uniform pore structure and ultrathin single-atom thickness. Herein, we computationally investigate the permeation performance of liquid ethanol–water mixtures across polyporous two-dimensional γ-graphyne sheets. It was found that, in the mixture, ethanol with larger molecular diameter permeates faster through the graphyne pores than water. The simulations demonstrate that pristine graphynes could act as highly-efficient ethanol-permselective membranes for separation of ethanol–water mixtures, with ethanol permeability remarkably higher than conventional membranes. This separation mechanism is distinctly different from the molecular-size dependent sieving process. The stronger hydrophobic interfacial affinity between graphyne and ethanol makes ethanol molecules preferentially adsorb on graphyne surface and selectively penetrate through graphyne pores. This penetration mechanism provides new understanding of molecular transport through atomically thick two-dimensional nanoporous membranes and this work is expected to be valuable in the potential development of highly-efficient membranes for liquid-phase mixture separation.

Morphology Control of SrCO_3 Crystals using Complexons as Modifiers in the Ethanol-water mixtures

Using SrC12-6H2O and Na2CO3 as the main raw materials and adding different complexons as modifiers with simple co-precipitation method, SrCO3 crystals with distinct morphologies like spherical, bundle-like, overlapping plate-like, hexagonal star-like, dumbbell-like, etc. can be synthesized in the ethanol-water mixtures. The samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Fourier transform infrared spectrograph （FT-IR）. The interrelated effect mechanism is presented in the end. Results show that the modifier carboxyl groups play a significant role in controlling the SrCO3 crystal morphologies, which can alter the crystal growth unit （Sr^2＋） supply mode and induce the crystal formation with the morphologies matching their spatial configurations.

Deformation and water/gas flow properties of claystone/bentonite mixtures

As a potential engineered barrier material for disposal of radioactive waste in clay formations,claystone aggregate excavated from the Opalinus clay(OPA),its mixture with bentonite MX80 in a mass ratio of 7/3,and pure bentonite were extensively investigated with respect to the hydro-mechanical properties and performances.With these materials,a series of parallel experiments was performed under sequentially applied conditions of hydration with synthetic porewater of the clay formation,consolidation and water flow under increased stresses,and gas injection into the water-saturated and compacted materials under loading.Significant responses of the clay mixtures were observed.Main findings include:(1)the hydration and induced swelling of the mixtures are mainly dominated by bentonite content and dry density;(2)the consolidation decreases the porosity and water permeability exponentially by 2-3 orders of magnitude to low values of 10^(-18)-10^(-20) m^(2) at stresses of 2-5 MPa,depending upon bentonite content;and(3)the gas penetration in the water-saturated and compacted bentonite is characterised by a cyclic pressure rising/dropping process limited in between the upper breakthrough and lower shut-off boundaries,whereas the compacted claystone and claystone/bentonite mixture allow for gas release at low and moderate pressures.The results are helpful for design of the engineered barriers for safe isolation of radioactive waste in repositories.

Fluorescence spectrum characteristic of ethanol-water excimer and mechanism of resonance energy transfer

The steady-state fluorescence spectrum characteristic of ethanol-water excimer has been studied in this paper. By analysing the features of the sharp emission spectrum with fine structures in a shortwave band and the characteristics of the broad and featureless fluorescence peaks in the longwave band, one can conclude that the excimers are formed between the new ethanol-water cluster molecules in the excited state and the ground state through the interaction among different chromophores. The excitation spectra in the two fluorescence bands have been studied, and their emission mechanisms have been ascertained based on the energy transfer theory. Furthermore, the critical distance of the resonance energy transfer has been calculated.

CF_4 decomposition without water over a solid ternary mixture consisting of NaF,silicon and one metal oxide

A solid ternary mixture consisting of NaF, silicon and one of the metal oxides such as Al2O3, MgO, CaO, SrO, BaO was prepared and used as a defluorinated reagent for CF4 decomposition. The results show that the initial conversion of CF4 reached 100% over NaF-Si-MgO and NaF-Si-CaO at 850°C, and the reagent with NaF/Si/MgO molar ratio of 33/34/33 exhibited a high reactivity with a full conversion of CF4 lasting for 57 min. The plausible paths of CF4 decomposition over NaF-Si-Al2O3, NaF-Si-MgO, NaF-Si-CaO, NaF-Si-SrO and NaF-Si-BaO are proposed.

Experimental adsorption equilibrium study and comparison of zeolite with water and ethanol for cooling systems

Two adsorption refrigeration working pairs of zeolite with water and ethanol were studied and the parameters of Dubinin-Astakhov model were regressed using the experimental data of equilibrium. The coefficient of heterogeneity varied from 1.305 to 1.52 for the zeolite-water pair and from 1.73 to 2.128 for zeolite-ethanol pair. The maximum adsorption capacity varied from 0.315 to 0.34 for zeolite-water and 0.23 to 0.28 for zeolite-ethanol, respectively. The results showed that the zeolite-water pair is suitable for solar energy cooling not only because of the high latent heat of vaporization of water but also because of the better equilibrium performance. On the other hand, zeolite-ethanol gives a high adsorption capacity at high regeneration tem-perature, which means it can be used in heat engine systems like buses and cars.

Evaluation of the Effectiveness of a 4-Months Continuous Injection of a Gas Mixture (CO₂and Inert Gases) on <i>Legionella</i>Contamination of a Hot Water Distribution System

Within the biofilm and scales Legionella is less far susceptible to the effects of the most frequently used biocides. The objective of this study was to evaluate the effect of a 4-months continuous injection of a gas mixture (CO2 and inert gas) in the hot water distribution system of a large hotel colonized by L. pneumophila sg3 on limiting biofilm formation and scales and in turn Legionella growth. Before the continuous injection of the gas mixture, out of the 15 sampling points examined every month 60% were colonized by Legionella (mean concentrations of 102 cfu/L in the boilers and the return loop, and 104 cfu/L in taps and showers). One week after the injection of the gas mixture and daily fluxing of the distal outlets, the level of colonization decreased (3 cfu/L). When it was decided to flux all the distal outlets only 1 day per week the mean concentration of Legionella increased again (>104 cfu/L) in all the sampling points. Thus, cleaning of the boilers was performed and distal outlets were again fluxed daily. One week after the level of contamination decreased again (2 cfu/L). Nonetheless, the colonization was not eliminated and when fluxing of the distal outlets was not performed every day the mean concentrations of Legionella raised up to >104 cfu/L. Results indicate that the gas mixture was able to reduce the level of colonization by Legionella only because associated to the fluxing of the distal outlets.

Co-liquefaction of Cotton Seed and Flos Populi in Sub-critical Water/Ethanol Solvent for Bio-oil with Medical Stone Based Additives

The co-liquefaction behaviors of cotton seed(CS)and flos populi(FP)were investigated in the sub-critical water/ethanol mixed solvent using the medical stone(MS)based additives.Oil products were characterized using FTIR,GC-MS,1HNMR,and 13CNMR techniques.The test results showed that the synergistic effect of co-liquefaction was obvious when the ratio of cotton seed and flospopuli was 1:1 without additives.The additives,such as 12-phosphotungstic acid(PW12),HZSM-5,PW12/HZSM-5 and modified medical stone(MS),PW12/MS,Ni/MS,Co/MS,Mo/MS and Co-Mo/MS,could increase the bio-oil yield;and the modified MS resulted in higher liquefied oil yield than that achieved by MS.Furthermore,additives such as Ni/MS,Mo/MS,and Co-Mo/MS also could increase the yield of aliphatic hydrocarbons in liquefied oil.The addition of Co-Mo/MS could lead to a highest liquefied oil yield of 28.8%,while the additive of PW12/HZSM-5 could result in a highest total conversion of 81.6%.Results also revealed that additives,such as PW12/MS,PW12,PW12/HZSM-5,Ni/MS,Co/MS,Mo/MS,and Co-Mo/MS,could increase the H2 production and decrease the CO2 production in gas products.

Molecular dynamics simulation of the interaction of ethanol-water mixture with a Pt surface

An analysis of the molecular dynamics of ethanol solvated by water molecules in the absence and presence of a Pt surface has been performed using DL_POLY_2.19 code. The structure and diffusion properties of an ethanol–water system have been studied at various temperatures from 250 to 600 K. We have measured the self-diffusion coefficients of the 50:50% ethanol–water solution;in the absence of a Pt surface our results show an excellent agreement–within an error of 7.4% – with the experimental data. An increase in the self-diffusion coefficients with the inclusion of a Pt surface has been observed. The estimation of the diffusion coefficients of both water and ethanol in the presence of a Pt surface shows that they obey the Arrhenius equation;the calculated activation energies of diffusion of ethanol and water are 2.47 and 2.98 Kcal/mole, respectively. The radial distribution function graphs and density profiles have been built;their correlations with the self-diffusion coefficients of both ethanol and water molecules are also illustrated.

Separated Hydrolysis and Fermentation of Water Hyacinth Leaves for Ethanol Production

Water hyacinth is a raw material for long-term sustainable production of cellulosics ethanol. In this study, the acid pretreatment and enzymatic hydrolysis were used to evaluate to produce more sugar, to be fermented to ethanol. Separated hydrolysis and fermentation （SHF） studies were carried out to produce ethanol from water hyacinth leaves. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions. The optimum pretreatment conditions included T = 135 ℃, t = 30 min, and sulfuric acid concentration = 0.1 M. The residue was enzymatically hydrolyzed using the mixture of enzymes cellulase, xylanase and pectinase. The maximum enzymatic saccharification of cellulosic material （76.8%） was achieved. SHF by mono-culture of Saccharomyces cerevisiae KM1195 achieved the highest yields of ethanol. Furthermore, ethanol production was accomplished with the co-culture ofS. cerevisiae TISTR5048 and Candida tropicalis TISTR5045 which produced the highest increase in ethanol Yield. In this case, the ethanol concentration of 3.42 （g/L）, percentage of the theoretical ethanol yield of 99.9%, the ethanol yield of 0.27 g/g and the productivity of 0.22 g/L/h were obtained. This suggested that mild acid pretreatment and co-cultureare promising methods to improve enzymatic hydrolysis and ethanol production from water hyacinth.

Single and Repeat Dose Toxicity Study of 7-Hydroxycoumarin, Ethanol, and Their Mixture in Rats

Acute and repeat-dose toxic effects ofHOC （7-hydroxycoumarin）, ethanol and their mixture were studied in rats. Single oral administration of HOC （5,000 mg/kg） caused transitional glycosuria associated with lowered serum glucose levels, decreased urea clearance. HOC given orally during 28 days （200 mg/kg） decreased serum glucose, and increased serum triglyceride concentrations. No enhancement of acute toxic effect of HOC （5,000 mg/kg） and ethanol （6,000 mg/kg） mixture was found in the acute toxicity study phase. Effect of HOC （200 mg/kg） and ethanol （750 mg/kg） during 28 days of exposure was less pronounced in comparison with HOC effect only, as far as neither decrease of glucose, nor increase oftriglyceride serum concentrations were found.

Design of Pilot Plant Packed Column for the Dehydration of Water from Ethanol-Water Mixtures

This use of biomass-based adsorbent has been explored for the column study of the adsorptive dehydration of water in ethanol-water mixtures. The column study was carried out using enzyme modified corn starch and the breakthrough curve parameters were used to design the packed bed column. The effect of flow rate on the breakthrough curves revealed that adsorption efficiency decreased with increased inflow rate. The empty bed contact time (τ) of the pilot plant packed column was 35.35 min while the breakthrough time is 40.78 min. 66.7% was the fraction of capacity left unused for the pilot plant from the design.