Aqueous Blends Research Articles

Development, Evaluation, and Pharmacokinetic Assessment of Polymeric Microarray Patches for Transdermal Delivery of Vancomycin Hydrochloride.

Methicillin-resistant Staphylococcus aureus (MRSA) can cause harmful and potentially deadly infections. Vancomycin remains the first-line antibiotic treatment for MRSA-derived infections. Nevertheless, as a peptide drug, it is poorly absorbed when administered orally because of its high molecular weight and low permeability in the gastrointestinal tract and is therefore administered intravenously for the treatment of systemic diseases. In order to circumvent some of the many drawbacks associated with intravenous injection, other routes of drug delivery should be investigated. One of the strategies which has been employed to enhance transdermal drug delivery is based on microarray patches (MAPs). This work, for the first time, describes successful transdermal delivery of vancomycin hydrochloride (VCL) using dissolving MAPs (DMAPs) and hydrogel-forming MAPs (HFMAPs). VCL was formulated into DMAPs and reservoirs [film dosage forms, lyophilized wafers, and compressed tablets (CSTs)] using excipients such as poly(vinyl pyrrolidone), poly(vinyl alcohol), sodium hyaluronate, d-sorbitol, and glycerol. In this study, HFMAPs were manufactured using aqueous blends containing poly(methylvinyl ether-co-maleic acid) cross-linked by esterification with poly(ethylene glycol). The VCL-loaded CSTs (60% w/w VCL) were the most promising reservoirs to be integrated with HFMAPs based on the physicochemical evaluations performed. Both HFMAPs and DMAPs successfully delivered VCL in ex vivo studies with the percentage of drug that permeated across the neonatal porcine skin recorded at 46.39 ± 8.04 and 7.99 ± 0.98%, respectively. In in vivo studies, the area under the plasma concentration time curve from time zero to infinity (AUC0-∞) values of 162.04 ± 61.84 and 61.01 ± 28.50 μg h/mL were achieved following the application of HFMAPs and DMAPs, respectively. In comparison, the AUC0-∞ of HFMAPs was significantly greater than that of the oral administration control group, which showed an AUC0-∞ of 30.50 ± 9.18 μg h/mL (p < 0.05). This work demonstrates that transdermal delivery of VCL is feasible using DMAPs and HFMAPs and could prove effective in the treatment of infectious diseases caused by MRSA, such as skin and soft tissue infections, lymphatic-related infections, and neonatal sepsis.

Numerical investigation of performance trade-off characteristics of a packed bed dehumidifier using aqueous blends of lithium chloride and calcium chloride

Current research in dehumidification systems is mainly focused on thermally driven liquid desiccant systems. However, the selection of proper desiccant solution has a greater significance on the performance of a dehumidifier. In this perspective, current work is presented with governing equations of energy, mass and species balance to study the performance of a dehumidifier. The governing equations are solved using finite difference method coupled with Jacobi’s model for an air–desiccant contact system of a cross-flow packed bed adiabatic dehumidifier operating with different desiccant blends of lithium chloride (LiCl) and calcium chloride (CaCl2) solution. The effect of variation in blend proportion on outlet parameters of a packed bed dehumidifier is patterned under various desiccant to air (L/G) mass flow rate ratios. It is observed that the addition of CaCl2 desiccant solution into LiCl changes the nature of thermo-physical properties of blends‚ which are predicted using non-random two liquid (NRTL) equation. Further, a trade-off analysis among the performance parameters is presented. It demonstrates that dehumidifier performance paradox such as enthalpy effectiveness (ɛh), moisture removal rate (MRR) and moisture effectiveness (ɛm) have a tendency to be optimal for 35% LiCl with 5% CaCl2 blend (BL1) among all blends at L/G ratio of 2. The variation of thermodynamic properties (air temperature, humidity, desiccant temperature and desiccant concentration) inside the dehumidifier module is visualized in terms of contour plots. Furthermore, the irreversibility in heat and mass transfer operation for the optimal blend is investigated in terms of physical and chemical exergy destruction paradigm. The result of such investigation elucidated that the maximum chemical exergy destruction is 0.88 kW, whereas the physical exergy destruction is 0.06 kW.

Development and characterisation of novel poly (vinyl alcohol)/poly (vinyl pyrrolidone)-based hydrogel-forming microneedle arrays for enhanced and sustained transdermal delivery of methotrexate.

Methotrexate (MTX) is one of the mainstays of treatment for rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) and it is mainly administered either orally or by subcutaneous (SC) injection, which are not so satisfactory. While orally administered MTX is associated with variable bioavailability and causes gastrointestinal side effects, including nausea and vomiting, SC injection is painful and produces high peak blood levels of MTX. Transdermal delivery presents an attractive alternative administration route. However, MTX passive permeation through the skin is hindered by the skin barrier and MTX physicochemical properties. To address these issues, hydrogel-forming microneedle arrays (HFMN) and a patch-like reservoir loaded with MTX (MTX-RV) were developed and combined to form a minimally invasive patch to deliver MTX transdermally in a sustained manner. HFMN were prepared from an aqueous blend of poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) which was crosslinked chemically with citric acid (CA) at 130˚C. MTX-RV was prepared from hydroxypropyl methylcellulose (HPMC) and glycerol. Both the HFMN and MTX-RV were fully characterised and then combined to form an integrated patch, which was evaluated ex vivo and in preclinical studies. The HFMN demonstrated a satisfactory mechanical strength and insertion capability into excised neonatal porcine skin, as well as moderate swelling properties. The MTX-RV incorporated a high dose of MTX (150.3±5.3µg/mg) without precipitation. The integrated patch delivered MTX at a steady-state flux of 506.8±136.9µg.cm2/h in an ex vivo setup. Furthermore, in preclinical studies performed in Sprague Dawley rats, MTX appeared in blood after 1h from patch application at a concentration of 7.6±2.0nM. MTX blood level increased gradually to reach its peak, Cmax=35.1±5.1nM, at 24h. Importantly, the HFMN were removed intact from the skin with only mild erythema, despite the cytotoxic nature of MTX. Accordingly, the integrated patch produced in this work represents a promising minimally invasive transdermal drug delivery system that can overcome the skin barrier and deliver MTX in a sustained manner. This may help in minimising or even avoiding the nausea and vomiting, associated with the conventional administration routes.

High-pressure measurement and thermodynamic modeling of the carbon dioxide solubility in the aqueous 2-((2-aminoethyl)-amino)-ethanol + sulfolane system at different temperatures

In this work, we presented the set of the experimental VLE data of solubility of carbon dioxide in the blend of 2-((2-Aminoethyl) amino) ethanol (AEEA) and sulfolane utilizing a quasi-static high-pressure equilibrium cell. We performed the measurements under isothermal conditions at temperatures of 313.15, 328.15 and, 343.15 K, and up to the maximum pressure of 5500 kPa. We used the various solvent mass compositions of (30–20–50), (30–10–60), (20–20–60), (20–10–70), (10–20–70), (10–10–80) wt% for the AEEA + sulfolane + H2O system. It was found that the CO2 loading in the solvent significantly enhanced by decreasing temperature and increasing pressure. Besides, CO2 solubility was improved by increasing both of sulfolane and AEEA concentration. Nevertheless, at the low CO2 loading region, the acid gas loading was reduced through enhancing the sulfolane concentration. Moreover, it was shown that an aqueous mixture of AEEA + sulfolane has a better performance than an aqueous blend of MDEA + sulfolane for CO2 removal. Furthermore, to model the CO2 solubility in the mixtures, a robust thermodynamics model based on the E-NRTL function was employed to correlate and predict the partial pressure of CO2 against its loading. The reasonable agreement between the calculated and experimental results demonstrated the high accuracy of the present thermodynamic modeling.

Elucidating the performance of (N-(3-aminopropyl)-1, 3-propanediamine) activated (1- dimethylamino-2-propanol) as a novel amine formulation for post combustion carbon dioxide capture

The exploration of energy-efficient amine solvents for CO2 removal from fluegas streams has been adopted as a key strategy for the wide implementation of CO2 capture technology in fossil fuel-based power plants for post-combustion CO2 capture. The current study entails an insight into the CO2 absorption performance of a novel aqueous amine blend of N-(3-aminopropyl)-1,3-propanediamine (APDA) and 1-dimethylamino-2-propanol (1DMAP) with special emphasis to the investigation of CO2 solubility at equilibrium state. In order to investigate the effect of promoter addition, the concentration of APDA has been gradually increased from 0.02 w to 0.10 w in the mixed solvent blend. The generated solubility data are correlated using two different modeling approaches viz., equilibrium based modified form of Kent-Eisenberg (KE) thermodynamic model and feed-forward neural network model. The model prediction is further extended to estimate pH and the overall speciation profile of all the molecular as well as ionic species prevailing in the solvent system. The CO2 solubility data are also analyzed in view of estimating the heat duty requirement for the absorption process. The heat of absorption of CO2 in aqueous (APDA + 1DMAP) blend has been calculated using theGibbs-Helmholtz equation. Along with solubility measurement, important thermophysical properties such as density and viscosity of the aqueous amine solution are also measured and correlated using established Redlich-Kister and Grunberg Nissan models.

Measurements and modeling of vapor liquid equilibrium of CO2 in amine activated imidazolium ionic liquid solvents

The mean surface temperature has increased considerably over the past few decades primarily due to the huge contribution of CO2, a greenhouse gas. Hence, the reduction of CO2 majorly from the point sources of emission has been a thrust domain of research. This work reports the measurements and modeling of CO2 solubility in newly proposed aqueous solvent blends of 1-butyl-3-methyl-imidazolium acetate ([bmim] [Ac]) and amine activators. Various amine activators viz. 1-(2-aminoethyl) piperazine (AEP) and bis (3-aminopropyl) amine (APA) have been employed in aqueous [bmim] [Ac] over the wide operating temperature and CO2 partial pressure range of (303.15˗323.15) K and (1–390) kPa, respectively. Along with this, qualitative 13C NMR and FTIR analysis have been also performed to assess the proposed reaction scheme. The experimental vapor liquid equilibrium data (VLE) were modeled by modified Kent-Eisenberg equilibrium model including the gas phase non-ideality and Feed forward neural network model. The equilibrium constants associated with [bmim] [Ac], AEP and APA deprotonation, and carbamate formation reactions are regressed to fit the experimental CO2 solubility data. Various important thermophysical properties such as surface tension, viscosity, sound velocity, refractive index and density have also been measured and correlated using established as well as newly proposed models.

Autonomous Electrolyte Discovery for Batteries with Experimentally Informed Bayesian Optimization

An autonomous battery electrolyte experimental platform capable of mixing multi-component electrolyte systems and characterizing the transport and electrochemical properties in a high-throughput manner is disclosed. A Bayesian optimization software package found novel electrolyte compositions through optimization of the high-dimensional electrolyte design space over key design objectives like electrochemical stability and conductivity.Electrolyte optimization is difficult because 1) electrolyte evaluation is expensive and takes time, and 2) the space of possible electrolytes is expansive, formed by many possible choices for solvents (often in ternary blends), salts (often in binary mixtures), and trace additives. Bayesian optimization methods are well suited for the optimization of high-dimensional functions with costly evaluations, often producing an efficient design-of-experiments to converge on multi-objective optimal formulations in few experiments. To expedite the optimization over the expansive design space, theoretical predictions of electrolyte properties via the Advanced Electrolyte Model were utilized as “priors” in the statistical model.Implementation of the novel experimental platform was carried out by two novel test stands developed to automate the mixing and characterization of electrolytes: Otto (for aqueous systems) and Clio (for aprotic/organic systems). The test stands characterized the ionic conductivity and electrochemical stability of electrolyte systems, featuring a four-electrode conductivity probe, pH meter, and a flow-through three-electrode cell and potentiostat. Clio also integrated electrochemically active electrodes for optimization of electrolyte/electrode systems. The active electrode systems used were common functional ceramic metal oxides.A software orchestration and data layer linked the test-stands to human experimenters and machine-learning packages through a web-services architecture; all experiment data and meta-data is saved in a database. Additional out-of-the-loop characterization was conducted on cathodic systems to validate composition, structure, and oxidation state.The aqueous design space consisted of aqueous blends of lithium and sodium salts, including nitrates, sulfates, and other commonly-used battery salts. High-concentration aqueous electrolyte candidates were discovered by optimizing of electrochemical voltage stability and conductivity, including low-cost, high-performing alternatives to known but costly aqueous electrolytes (e.g. LiTFSI). Clio’s design space includes blends of both aprotic organic solvents and solutes in additional to various compositions of electrochemically active electrodes. The test-stands are demonstrated to be significantly faster than common human experimentation techniques, converging on novel, optimized electrolyte mixtures in mere hours or days of experimentation.

Absorption of CO2 in aqueous blend of methyldiethanolamine and arginine

AbstractThe objective of this research is to study for the first time the effect of adding l‐arginine (Arg) amino acid on the solubility of carbon dioxide in aqueous solution of N‐methyldiethanolamine (MDEA). The study was carried out at different mixing ratios of MDEA and Arg at a total concentration of 2 moles per litre. The CO2 partial pressure varied from about 10 to 100 kPa, and the temperature varied from 293 K to 323 K. The experimental results showed improved solubility of CO2 with the addition of Arg at CO2 partial pressures below 20 kPa. However, for CO2 partial pressure of above 20 kPa, the addition of Arg caused a decrease in the solubility of CO2. The obtained loading data were correlated using a semiempirical (SE) vapour liquid equilibrium (VLE) model with an average absolute deviation (AAD) less than 4.1% between the predicted and the experimental values. An estimation of the heat of CO2 absorption in the solution was obtained using an analytical expression for ΔHabs derived from the SE model and was found to be in the range of 29‐ to 40‐kJ/mole CO2. From the finding of this work, it is anticipated that the studied novel blended solvent will effectively reduce CO2 capture costs as the CO2 content of most gas streams is less than 20% by volume, which is specifically true for natural gas and a large number of industrial flue gas streams.

Rheological Test for the Homogeneity of Aqueous Blends of Associative Polymer Network and Entangled Linear Polymer

Rheological Test for the Homogeneity of Aqueous Blends of Associative Polymer Network and Entangled Linear Polymer

Effect of Liquid Flow Rate on Carbon Dioxide Absorption Performance Using Aqueous Potassium Carbonate Promoted with Glycine at Elevated Pressure Condition of Packed Absorption Column

This paper presented the absorption removal efficiency for carbon dioxide (CO2) removal from natural gas using an environmental friendly solvent, potassium carbonate promoted with glycine. Recently, CO2 capture using this solvent (with precipitating) was studied by previous researchers. However, the precipitates of the solvent increase the potential of blockage in the packing and piping thus result failure in absorption processes. Therefore, this study focused to assess the CO2 removal efficiency of non-precipitating potassium carbonate promoted with glycine. This green solvent contains aqueous blend of 20 wt% potassium carbonate and 8 wt% glycine. The absorption performance of the solvent was obtained by demonstrated a few experimental works using a bench scale packed absorption column. The packing type was Sulzer metal gauze and the column consisted of six sampling point which located equidistance along the packing. The effect of liquid flow rate was assessed in term of its CO2 removal efficiency and concentration profile along the packing. The study shows the increasing trend of CO2 removal as liquid flow rate increases. Higher liquid/molar flow rate gas (L/G) offers a better absorption performance compared to lower L/G ratio. The results demonstrated the efficient absorption up to 77% using non-precipitating potassium carbonate promoted with glycine.

Selection of efficient absorbent for CO2 capture from gases containing low CO2

Amine-based absorption processes are widely used in natural gas processing, but recently they have been considered for CO2 capture from flue gas emitted from thermal power plants. The main issue of amine used in the CO2 capture process is the high cost of solvent regeneration. So, this issue can be solved by using efficient amine absorbent. The amine type absorbents employed in the experimentation were an aqueous blend of 2-(Diethylamino)ethanol (DEEA) with different types of diamine activators such as piperazine (PZ), 2-(2-aminoethylamino)ethanol (AEEA), hexamethylenediamine (HMDA), ethylenediamine (EDA), and 3-(Dimethylamino)-1-propylamine (DMAPA). An absorption experiment was performed to evaluate the CO2 absorption performance in terms of CO2 loading, absorption capacity, and absorption rate. The experiment was performed to assess the CO2 desorption performance in terms of desorption capacity, desorption rate, cyclic capacity, and regeneration efficiency. From the results of absorption-desorption and comparison with benchmark amine absorbent MEA, the aqueous blend of DEEA and HMDA indicated the best performance for CO2 capture applications among all the tested amine blends.

CO2 capture using aqueous 1-(2-Hydroxyethyl) piperidine and its blends with piperazine: Solubility and enthalpy

In this article, equilibrium CO2 solubility in aqueous 1-(2-Hydroxyethyl) piperidine (HEP) solutions pertaining concentrations (1, 2, 3) mol/L in the temperature range (303.15–323.15) K, and CO2 partial pressure range 0.1–100 kPa are presented. HEP; being a tertiary alkanolamine, its rate of CO2 absorption is comparatively slower than primary or secondary alkanolamine. Piperazine (PZ), a rate promoter was added to HEP in 1:4 mol ratio to form blends having enhance rate of CO2 absorption. Equilibrium CO2 solubility in four different aqueous blends; (0.8 mol/L HEP + 0.2 mol/L PZ), (1.6 mol/L HEP + 0.4 mol/L PZ), (2.4 mol/L HEP + 0.6 mol/L PZ), (3.2 mol/L HEP + 0.8 mol/L PZ) were measured over the temperature range of (303.15–323.15) K and CO2 partial pressure spanning over 0–70 kPa. Equilibrium constant for deprotonation reaction of HEP was estimated by measuring pKa of aqueous HEP solution at 298.15, 303.15, 313.15, 323.15 and 333.15 K. Experimentally obtained CO2 solubility data for single and blended amine solutions were correlated efficiently using activity coefficient model with AAD % of 3.76 and 3.22, respectively. Speciation of both single and blended amine solutions in their equilibrated liquid phase were predicted. Interaction parameters obtained through thermodynamic modelling of equilibrium solubility data for single and blended amine solutions were used to predict the enthalpy of CO2 absorption.

Equilibrium Solubility Measurement and Modeling of CO2 Absorption in Aqueous Blend of 2-(Diethyl amino) Ethanol and Ethylenediamine

The equilibrium CO2 solubility in an aqueous blend of 2-(diethyl amino) ethanol (DEEA) and ethylenediamine (EDA) was performed at atmospheric pressure with the use of a laboratory scale bubbling absorber. The total concentration of amine blend solution in the range of 1.13–4.90 mol·kg–1 and the EDA mole fraction in the total amine blend in the range of 0.05–0.20 were taken. The experiments for the measurement of CO2 solubility were performed at a temperature range of 303.15–333.15 K and CO2 partial pressure range of 10.13–20.27 kPa. The analysis of CO2 in the liquid phase was accomplished by a direct titration method using HCl solution. The solubility data of CO2 in DEEA+EDA solution of the present study were compared with data available in the literature. The experimental results were applied to develop an empirical mathematical model with an average absolute deviation of 7.03% to predict the CO2 equilibrium solubility in DEEA+EDA solution within the specified range of operating conditions. In addition, ...

CO2 Absorption Capacity and its Enthalpy of Absorption in Aqueous Blend of MDEA/Piperazine/Arginine

In this work, the solubility data of CO2 in aqueous blends of N-Methyldiethanolamine, Piperazine and Arginine (MDEA/PZ/ARG) of a total concentration of two moles is presented. CO2partial pressure was varied from 9 to 99 kPa while temperature ranged from 293 to 323 K in increment of 10 degrees. The experimental results showed that the solubility of CO2 decreased with increasing ARG ration in the mixture. These results were modelled using a semi-empirical (SE) vapor liquid equilibrium (VLE) model. The model was found able to adequately represent the experimental data with an average absolute deviation (AAD) less than 3.13 %. Using a truncated form of the semi-empirical model, the heat of CO2 absorption, ΔHab, at low pressure was estimated and found to be in the range of 32-66 kJ/mole CO2 absorbed.

Evaluation of the Toxicity of Diluted Aqueous Blends of a Series of Hydrocarbons

Evaluation of the Toxicity of Diluted Aqueous Blends of a Series of Hydrocarbons

High-pressure experimental and theoretical study of CO2 solubility in aqueous blends of lysine salts with piperazine as new absorbents

Vapour-liquid equilibrium of carbon dioxide loaded potassium and sodium l-lysine salts have been investigated in the region of high-pressure and high loadings. The equilibrium solubility of carbon dioxide was measured in separate aqueous l-lysine alkaline salts for a range of temperature (303.15–363.15 K), solution concentrations (1.0–3.0 M) and pressure (95–4204 kPa). In addition to that, solubility of carbon dioxide in blends of both aforementioned amino acid salts with piperazine were investigated. All the studied solutions exhibited an increase in the carbon dioxide loading values with increase in the pressure and had a negative relationship with increase in the temperature and solvent concentration. Furthermore, the experimental data was correlated by the Kent-Eisenberg model. The correlated values shows a good agreement (AAD% of 5.15%) with experimental values. The regressed parameters of the model allows satisfactory estimation of the loadings of carbon dioxide in all studied solutions, for parametric studies. The study shows that l-lysine salts are potential green solvents for the carbon dioxide capture at high pressure.

Assessment of mass transfer correlations used in post-combustion CO2 capture by piperazine activated 2-amino-2-methyl-1-propanol (a-AMP)

The prevalent solvents used in CO2 capture processes have such drawbacks as degradability, high energy consumption for solvent regeneration, low absorption capacity, and corrosive nature which have convinced the researchers to suggest a new combination of alkanolamines in place of the commonly-used solvents like MEA. Since Rate-Based model, compared to Equilibrium model, gives more accurate simulations of CO2 capture processes by amine solvent, it is used in this study. Mass transfer correlations are significant parameters in Rate-Based model, and using them improperly will lead to considerable disagreement between real and simulated results.In the present work, mass transfer coefficients in CO2 capture processes are evaluated using an aqueous blend of piperazine activated 2-amino-2-methyl-1-propanol (a-AMP) solution for the first time. It is done according to Khan et al. (2016) experimental results in 36 points and for different operational conditions. In the first evaluation, 12 sets of data are achieved following the changes of the operational parameters, gas flow rate and CO2 partial pressure, while other parameters such as operational absorption temperature, solvent flow rate and solvent blends of AMP + PZ remain constant. The studies indicate that considering the amount of CO2 absorbed, the Mean Absolute Errors (MAE) of Onda et al., Bravo-Fair, and Billet-Schultes mass transfer coefficients are 12%, 7.63%, and 3.2% respectively in comparison with Khan et al. results. The second evaluation is also done in 12 operational points regarding the variations of PZ concentration and operational absorption temperature. Other parameters remain unchanged in this evaluation, too.This study demonstrates that Billet-Schultes correlations own higher accuracy compared to the Onda et al. and Bravo-Fair. Mean Absolute Errors (MAE) of Onda et al., Bravo-Fair, and Billet-Schultes are 12.74%, 8.26%, and 2.04% respectively. The third evaluation of this work is of rich solvent loading (absorber loading). Similarly, this evaluation is performed in 12 operational points in regard to the changes of CO2 partial pressure and the ratio of AMP to PZ, while other operational parameters are kept constant. This evaluation likewise shows that, compared to two other ones, Billet-Schultes correlations have more precision when utilized in CO2 capture processes by the a-AMP solvent. Mean Absolute Error (MAE) of Onda et al., Bravo-Fair, and Billet-Schultes in predicting absorber loading and in accordance with experimental data are 24.21%, 16.44%, and 6.23% respectively.

New AMP/polyamine blends for improved CO2 capture: Study of kinetic and equilibrium features

Abstract2‐Amino‐2‐methyl‐1‐propanol (AMP), which is the sterically hindered form of monoethanolamine (MEA), is a credible substitute to conventional CO2‐capturing solvents. Its performance can be improved by blending with a highly reactive polyamine promoter. Two such aqueous blends of AMP/TETA and AMP/TEPA were chosen here (TETA = triethylenetetramine and TEPA = tetraethylenepentamine). The kinetics of CO2 absorption in the proposed blends was investigated at 308, 313, and 318 K using the stirred cell technique. The concentrations of AMP and polyamine were varied between 2 to 3 kmol/m3 and 0.1 to 0.5 kmol/m3, respectively. From the measured values of the fast pseudo‐first order constants, the second‐order rate constants for the reactions of CO2 with TETA (14 695 m3/(kmol s)) and TEPA (19 250 m3/(kmol s)) were determined at T = 313 K. Both TETA and TEPA react faster with CO2 than MEA. Further, the respective activation energy values were found (40 and 37 kJ/mol). Finally, the equilibrium solubility of CO2 for both blends was measured at T = 303 K. The loading capacity was higher than that for the aqueous blends of AMP/MEA, AMP/DEA, and AMP/MDEA (here, DEA and MDEA denote diethanolamine and N‐methyldiethanolamine). The highest value of loading capacity (1.12 mol CO2/mol amine at 2.01 kPa equilibrium partial pressure of CO2) was noted in AMP/TEPA mixtures. The new findings on our proposed blends will strengthen the AMP/polyamine application in CO2 separation.

Dissolving Microneedles for Intradermal Vaccination against Shigellosis.

Intradermal (ID) immunization is of increasing interest due to the easy accessibility and excellent immunogenic properties of the skin. Among ID immunization methods, dissolving microneedles (MNs) have appeared as an alternative to traditional hypodermic immunization, offering many advantages, such as being an easily administered method, with no need for health personnel, painless, and avoiding the use of needles and sharp wastage. In this study, an affordable and easy-to-produce MNs method was developed based on aqueous blends of 30% w/w poly (methyl vinyl ether-co-maleic anhydride). As an antigen model, a subunit vaccine candidate based on outer membrane vesicles from Shigella flexneri was used. Both unloaded and antigen-loaded MNs were synthetized and characterized. The MNs were successfully validated in an in vitro Parafilm M® skin model and in a pig skin ex vivo model. Biodistribution studies were performed in BALB/c mice using 99mTcO4− radiolabeled samples. Results indicated that the vesicle vaccine was successfully released from the MNs and targeted gastrointestinal tract after 6 h post-administration. In vivo immunization and protection studies were performed in BALB/c mice. Mice were intradermally immunized through ear skin with one single dose of 200 μg antigenic complex, eliciting the production of specific systemic IgG and mucosal IgA. Moreover, MNs were able to protect mice from an experimental infection with 1×106 CFU/mouse of S. flexneri four weeks after immunization. This work demonstrates for the first time the potential of outer membrane vesicle-loaded dissolving MNs for ID vaccination against enteropathogens like Shigella.

Combustion, performances, and emissions characteristics of diesel engine fuelled with diesel-aqueous zinc oxide nanofluid blends

ABSTRACT Finding the new fuel blend as a green fuel by mixing aqueous zinc oxide nanofluid with diesel to improve diesel engine combustion and performance is the aim of this study. Varying the nanofliud dosing level in diesel from 30 cc to 60 cc, four blends are prepared and their properties are measured. Engine performance tests are conducted with the blends and the best blend is identified as D + 50ZN. The energetic nanoparticles present in the aqueous nanofluid possess large surface area per unit volume, it exhibits high catalytic activity with hydrocarbon causing oxidation of hydrocarbon and also micro explosion phenomena of aqueous nanofluid blend helps to evaporate the blend quickly as soon as the fuel injected from injector with high speed and some millimeters away from the normal spay limit leading to quick preparation of charge during the delay period. Hence, the fuel is completely burnt during the combustion period. Among all blends, The D + 50ZN showed a maximum improvement of about 5.38% in brake thermal efficiency and remarkable reduction in NOX, smoke, HC, and CO is observed as 12.97%, 22.08%, 24.54%, and 10.34%, respectively at maximum rated power output. Abbreviation: ASTM: American Society for Testing and Materials; aTDC: After Top Dead Center; BP: Brake Power; BSFC: Brake Specific Fuel Consumption; bTDC: Before Top Dead Center; BTE: Brake Thermal Efficiency; CO: Carbon Monoxide; DDSA: Dodecenyl Succinic Anhydride; EDS: Energy Dispersive Spectroscopy; HC: Hydrocarbons; JCPDS: Joint Committee on Powder Diffraction Standards; NOX: Oxides of Nitrogen; ppm: Part Per Million; SEM: Scanning Electron Microscope; XRD: X-Ray Diffraction Pattern; ZN: Aqueous Zinc Oxide Nanofluid; ZnO: Zinc Oxide