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1.
The rheological studies of Lactic Acid (LA)-based Natural Deep Eutectic Solvents (NADES) are provided in the present investigation. Those mechanisms were also studied in which three distinct Hydrogen Bond Acceptors (HBAs) of Choline Chloride (ChCl), Betaine (Be), and β-Alanine (β-Al), after being added to a specific Hydrogen Bond Donor (HBD) at a predefined mole-to-mole ratio of 1:1, affected the rheological properties of the prepared NADES. The alterations in the rheology-related characteristics in association with the mechanical and physical properties indicate the tolerance of the material under various operational conditions in the field and show their potential utilization as environmentally suitable and feasible solvents for industrial applications. In the present research, the viscoelastic properties of the three samples of NADES were assessed along with their shear flow properties. The backward and forward temperature change in the Apparent Viscosity (AV) pattern related to the NADES system was described by a rheogram. Furthermore, the density was determined and compared with the AV while considering the temperature-related factor. On a further note, the viscoelastic characteristics were utilized in describing and investigating the network disturbance on the level of the microstructure of NADES upon frequency sweep. A series of experiments were carried out using Thermogravimetry Analysis (TGA) to investigate the thermo-physical properties to optimize them. The rheological properties of shear flow measurements were analyzed using the Bingham model that is best suited for the AV developed with the shear rate with the dynamic yield stress of three systems. The Bingham model was used to determine the lowest stress necessary to disturb the network structure and commence the flow of LA-based NADES. Overall, the viscoelastic behavior of the LA-based NADES revealed the dissimilarity between their strength and viscosity. In addition, shear flow investigations demonstrated that LA-based NADES systems exhibit non-Newtonian properties and substantial shear-thinning effects equivalent to those of alternative IL sorbents. Assessing the rheological properties of LA-based NADES is crucial for a better understanding the key challenges associated with high viscosity. Defining the transport yield stress requirements for NADES systems under different conditions benefits their future development and potentially opens the door to more challenging applications.  相似文献   

2.
Deep Eutectic Systems (DESs) are obtained by combining Hydrogen Bond Acceptors (HBAs) and Hydrogen Bond Donors (HBDs) in specific molar ratios. Since their first appearance in the literature in 2003, they have shown a wide range of applications, ranging from the selective extraction of biomass or metals to medicine, as well as from pollution control systems to catalytic active solvents and co-solvents. The very peculiar physical properties of DESs, such as the elevated density and viscosity, reduced conductivity, improved solvent ability and a peculiar optical behavior, can be exploited for engineering modular systems which cannot be obtained with other non-eutectic mixtures. In the present review, selected DESs research fields, as their use in materials synthesis, as solvents for volatile organic compounds, as ingredients in pharmaceutical formulations and as active solvents and cosolvents in organic synthesis, are reported and discussed in terms of application and future perspectives.  相似文献   

3.
Deep eutectic solvent (DES) has been widely used in the field of metal electrodeposition as an economical and environmentally friendly green solvent. Metallic bismuth films were prepared by electrodeposition from choline chloride-malonic acid (ChCl-MA) deep eutectic solvent (DES) containing BiCl3. Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy were used to study the structure of ChCl-MA-BiCl3, and the results showed that Bi(III) was in the form of [BiCl6]3− ions. The viscosity of ChCl-MA-BiCl3 ranges from 200 to 1200 mPa·s at temperatures from 363 K to 323 K. The conductivity of 0.01 M Bi(III) in ChCl–MA is 3.24 ms·cm−1 at 363 K. The electrochemical behavior and electrodeposition of Bi(III) in DES were investigated by cyclic voltammetry (CV) and chronoamperometry. The results showed that the electrodeposition reaction was a quasi-reversible reaction controlled by the diffusion and the nucleation of bismuth was a three-dimensional instantaneous nucleation. The diffusion coefficient of Bi(III) in ChCl-MA was 1.84 × 10−9 cm2·s−1. The electrodeposition product was observed by scanning electron microscopy (SEM), and the results showed that the deposition potential has a significant influence on the morphology of the bismuth film. X-ray photoelectron spectroscopy (XPS) shows that bismuth and bismuth oxides are present in the deposited film obtained by electrodeposition.  相似文献   

4.
Choline-based deep eutectic solvents (DESs) are potential candidates to replace flammable organic solvent electrolytes in lithium-ion batteries (LIBs). The effect of the addition of a lithium salt on the structure and dynamics of the material needs to be clarified before it enters the battery. Here, the archetypical DES choline chloride:urea at 1:2 mole fraction has been added with lithium chloride at two different concentrations and the effect of the additional cation has been evaluated with respect to the non-doped system via multinuclear NMR techniques. 1H and 7Li spin-lattice relaxation times and diffusion coefficients have been measured between 298 K and 373 K and revealed a decrease in both rotational and translational mobility of the species after LiCl doping at a given temperature. Temperature dependent 35Cl linewidths reflect the viscosity increase upon LiCl addition, yet keep track of the lithium complexation. Quantitative indicators such as correlation times and activation energies give indirect insights into the intermolecular interactions of the mixtures, while lithium single-jump distance and transference number shed light into the lithium transport, being then of help in the design of future DES electrolytes.  相似文献   

5.
The methane fermentation of organic waste is one way to minimize organic waste, which accounts for 77% of the global municipal waste stream. The use of biochar as an additive for methane fermentation has been shown to increase the production potential of biogas. Sulfur waste has a potential application to synergistic recycling in a form of composites with other materials including biochar. A composite product in the form of a mixture of biochar and molten sulfur has been proposed. In this experiment, additions of the sulfur–biochar composite (SBC) were tested to improve the fermentation process. The biochar was produced from apple chips under the temperature of 500 °C. The ground biochar and sulfur (<1 mm particle size) were mixed in the proportion of 40% biochar and 60% sulfur and heated to 140 °C for sulfur melting. After cooling, the solidified composite was ground. The SBC was added in the dose rate of 10% by dry mass of prepared artificial kitchen waste. Wet anaerobic digestion was carried out in the batch reactors under a temperature of 37 °C for 21 days. As an inoculum, the digestate from Bio-Wat Sp. z. o. o., Świdnica, Poland, was used. The results showed that released biogas reached 672 mL × gvs−1, and the yield was 4% higher than in the variant without the SBC. Kinetics study indicated that the biogas production constant rate reached 0.214 d−1 and was 4.4% higher than in the variant without the SBC.  相似文献   

6.
Deep Eutectic Solvents (DESs) are experiencing growing interest as substitutes of polluting organic solvents for their low or absent toxicity and volatility. Moreover, they can be formed with natural bioavailable and biodegradable molecules; they are synthesized in absence of hazardous solvents. DESs are, inter alia, successfully used for the extraction/preconcentration of biofunctional molecules from complex vegetal matrices. Onion skin is a highly abundant waste material which represents a reservoir of molecules endowed with valuable biological properties such as quercetin and its glycosylated forms. An efficient extraction of these molecules from dry onion skin from “Dorata di Parma” cultivar was obtained with water dilution of acid-based DESs. Glycolic acid (with betaine 2/1 molar ratio and L-Proline 3/1 molar ratio as counterparts) and of p-toluensulphonic acid (with benzyltrimethylammonium methanesulfonate 1/1 molar ratio)-based DESs exhibited more than 3-fold higher extraction efficiency than methanol (14.79 µg/mL, 18.56 µg/mL, 14.83 µg/mL vs. 5.84 µg/mL, respectively). The extracted quercetin was also recovered efficaciously (81% of recovery) from the original extraction mixture. The proposed extraction protocol revealed to be green, efficacious and selective for the extraction of quercetin from onion skin and it could be useful for the development of other extraction procedures from other biological matrixes.  相似文献   

7.
The capacitance and operating voltage of supercapacitors as well as their energy density have been increased by development of different materials and electrolytes. In this paper, two strategies, for the first time, were used to improve energy density: Mn3O4- and N-dual doped carbon electrode and aqueous mixture of multivalent ions as electrolyte. Mn3O4- and N-dual doped carbon was prepared by a novel and cost-effective procedure using deep eutectic solvent. XRD, XPS, and FTIR confirmed presence of Mn3O4 and nitrogen, while SEM and EDS elemental mapping showed micrometer-sized nanosheets with uniform distribution of C, O, N, and Mn atoms. Charge storage behavior of carbon was tested in aqueous multivalent-based electrolytes and their mixture (Ca2+-Al3+). Regarding both specific capacitance and workable voltage, the Ca2+-Al3+ mixed electrolyte was found as the best optimal solution. The calcium addition to the Al-electrolyte allows the higher operating voltage than in the case of individual Al(NO3)3 electrolyte while the addition of Al3+ ion in the Ca(NO3)2 electrolyte improves the multivalent-ion charge storage ability of carbon. As a result, the specific energy density of two-electrode Mn3O4@N-doped carbon//Al(NO3)2+Ca(NO3)2//Mn3O4@N-doped carbon supercapacitor (34 Wh kg−1 at 0.1 A g−1) overpasses the reported values obtained for Mn-based carbon supercapacitors using conventional aqueous electrolytes.  相似文献   

8.
The formability of the drawn part in the deep drawing process depends not only on the material properties, but also on the equipment used, metal flow control and tool parameters. The most common defects can be the thickening, stretching and splitting. However, the optimization of tools including the die and punch parameters leads to a reduction of the defects and improves the quality of the products. In this paper, the formability of the camera cover by aluminum alloy A1050 in the deep drawing process was examined relating to the tool geometry parameters based on numerical and experimental analyses. The results showed that the thickness was the smallest and the stress was the highest at one of the bottom corners where the biaxial stretching was the predominant mode of deformation. The problems of the thickening at the flange area, the stretching at the side wall and the splitting at the bottom corners could be prevented when the tool parameters were optimized that related to the thickness and stress. It was clear that the optimal thickness distribution of the camera cover was obtained by the design of tools with the best values—with the die edge radius 10 times, the pocket radius on the bottom of the die 5 times, and the punch nose radius 2.5 times the sheet thickness. Additionally, the quality of the camera cover was improved with a maximum thinning of 25% experimentally, and it was within the suggested maximum allowable thickness reduction of 45% for various industrial applications after optimizing the tool geometry parameters in the deep drawing process.  相似文献   

9.
Studies have shown a promoting effect of food on small intestinal absorption. Casein hydrolysate seems be more effective in increasing of D-xylose absorption in dogs than the whole protein and lactulose. The purpose this study was to analyze the effect of groups of peptides derived from casein hydrolysate on the absorption of d-Xylose and intestinal transit time in normal subjects. Seven normal volunteers participated in the study. Three peptide fractions were isolated from casein enzymatic hydrolysate by means of a preparative HPLC silica column. On separate days subjets drank test solutions containing lactulose, d-xylose, and d-xylose with one of three peptide groups. The hydrogen breath test was used to indirectly estimate d-xylose absorption and orocecal transit time. Two peptide fractions when added to d-xylose were followed by an increased absorption characterized by decreased H2 production. A nonstatistically significant increase of orocecal transit time was observed with these peptides.  相似文献   

10.
Fischer  U.  Freyse  E. -J.  Jutzi  E.  Besch  W.  Raschke  M.  Höfer  S.  Albrecht  G. 《Diabetologia》1983,24(3):196-201
Summary The appearance rate of insulin (calculated insulin secretion rate) in the circulating blood after subcutaneous injection was estimated in diabetic dogs from serial measurements of immunoreactive insulin concentrations using a simple mathematical model based on the insulin half-life and the distribution space. In the case of highly purified monocomponent porcine insulin, maximum concentrations occurred after 30–60 min. The duration of insulin appearance was dose-dependent and the rate of appearance could be described by a bi-exponential function. It was linearly dose-dependent but the effect on glycaemia showed saturation kinetics. The action of the injected dose on the fasting glycaemia diminished when the appearance rate became <0.3 mU · kg-1 · min-1. Fractional dose recovery was between 70% and 90% and was not different between depot and regular insulin. Appearance kinetics were not significantly affected by the initial glycaemia. The model presented provides a means for quantitative characterization of different insulin preparations.  相似文献   

11.
Adherent hardened cement paste attached to recycled concrete aggregates (RCA) generally presents a higher porosity than natural aggregates, which induces a lower porosity in the properties of RCA. The characterization of the adherent hardened cement paste content (HCPC) in the fine RCA would promote better applications of RCA in concrete, but the determination of HCPC in fine RCA is not well established. A simple method based on salicylic acid dissolution was specifically developed to quantify the HCPC in RCA, especially for RCA containing limestone aggregates. The results demonstrated that the soluble fraction in salicylic acid (SFSA) was equal to the HCPC for white cement and slightly lower for grey Portland cement, which was also confirmed by a theoretical approach using modelling the hydration of cement paste with the chemical equations and the stoichiometric ratios. The physical and mechanical properties of RCA (e.g., water absorption) were strongly correlated to the SFSA. For industrial RCA, SFSA did not give the exact value of HCPC, but it was sufficient to correlate HCPC with the other properties of RCA. The water absorption could be estimated with good accuracy for very fine RCA (laboratory-manufactured RCA or industrial RCA) by extrapolating the relationship between water absorption and HCPC, which is very important for concrete formulation.  相似文献   

12.
To make a food preparation containing radioactively labelled cobalamins, rabbits were given repeated injections with 57Co-labelled cyanocobalamin. The liver was removed, homogenized, and fried for 1 min or boiled for 30 min. Of the radioactivity in the fried homogenate 41.7% was recovered in the centrifuged supernatant compared with 50.8% in the boiled homogenate. The radioactivity in the supernatants had a molecular size close to that of free 57Co-labelled cyanocobalamin. Forty-two per cent of the radioactivity in the whole homogenate had been incorporated into 5-deoxyadenosyl-, 10% into methyl-, and 16.5% into hydroxy-cobalamin. To assess the validity of a double-isotope method for measuring the intestinal absorption of doses of the 57Co-labelled liver cobalamins, 51CrCl3 was used as a non-absorbable marker. In 14 healthy volunteers the correlation coefficient between the absorption measured by the double-isotope technique and the faecal excretion test was highly significant (r = 0.96, p < 0.005), and there was only a small variation in the 57Co/51Cr ratio in successive stool collections. In 11 patients with chronic diarrhoea there was a significant correlation between the absorption measured by the double-isotope technique and the faecal excretion test (r = 0.92, p < 0.005), but in some patients there was considerable variation in the 57Co/51Cr ratio in successive stool collections.  相似文献   

13.
The aim of this study was to determine the effects of main factors and interactions on the color removal performance from dye solutions using the electrocoagulation process enhanced by adsorption on Granular Activated Carbon (GAC). In this study, a mathematical approach was conducted using a two-level fractional factorial design (FFD) for a given dye solution. Three textile dyes: Acid Blue 74, Basic Red 1, and Reactive Black 5 were used. Experimental factors used and their respective levels were: current density (2.73 or 27.32 A/m2), initial pH of aqueous dye solution (3 or 9), electrocoagulation time (20 or 180 min), GAC dose (0.1 or 0.5 g/L), support electrolyte (2 or 50 mM), initial dye concentration (0.05 or 0.25 g/L) and current type (Direct Current—DC or Alternative Pulsed Current—APC). GAC-enhanced electrocoagulation performance was analyzed statistically in terms of removal efficiency, electrical energy, and electrode material consumptions, using modeling polynomial equations. The statistical significance of GAC dose level on the performance of GAC enhanced electrocoagulation and the experimental conditions that favor the process operation of electrocoagulation in APC regime were determined. The local optimal experimental conditions were established using a multi-objective desirability function method.  相似文献   

14.
Temperature changes on the surface of the skin lead to modifications of subcutaneous microcirculation. This phenomenon is employed in a standardized way by the InsuPad device to stabilize skin conditions before injections, which is associated with enhanced prandial insulin absorption. Three programmed warming cycles to 40°C within 50 minutes are resulting in faster insulin appearance in the plasma. Early standardized meal tolerance studies indicated a substantial improvement in postprandial glucose control when the same short-acting insulin analog dose was applied using InsuPad, and a dose reduction by 20% resulted in comparable glucose excursions. Similar results were obtained when patients applied the device under real-world conditions for 1 month. The InsuPad device was also tested in a prospective, controlled, parallel 3-month real-world study with 145 well-controlled but insulin-resistant patients with type 1 or type 2 diabetes. Patients were treated to target in both treatment arms (6.2 ± 0.5% in each group), with or without the device. However, patients with InsuPad needed 28% less prandial insulin, needed 12.5% less total insulin, and had 46% less confirmed hypoglycemic events (blood glucose < 63 mg/dL) as compared to the control group. Except for very few inflammatory or allergic skin reactions, there were no device-specific adverse events reported from these studies. In conclusion, use of InsuPad when applying prandial insulin doses may result in a safer and more efficient treatment of type 1 or type 2 diabetes.  相似文献   

15.
Additive manufacturing, in particular the powder bed fusion of metals using a laser beam, has a wide range of possible technical applications. Especially for safety-critical applications, a quality assurance of the components is indispensable. However, time-consuming and costly quality assurance measures, such as computer tomography, represent a barrier for further industrial spreading. For this reason, alternative methods for process anomaly detection using process monitoring systems have been developed. However, the defect detection quality of current methods is limited, as single monitoring systems only detect specific process anomalies. Therefore, a new methodology to evaluate the data of multiple monitoring systems is derived using sensor data fusion. Focus was placed on the causes and the appearance of defects in different monitoring systems (photodiodes, on- and off-axis high-speed cameras, and thermography). Based on this, indicators representing characteristics of the process were developed to reduce the data. Finally, deterministic models for the data fusion within a monitoring system and between the monitoring systems were developed. The result was a defect detection of up to 92% of the melt track defects. The methodology was thus able to determine process anomalies and to evaluate the suitability of a specific process monitoring system for the defect detection.  相似文献   

16.
目的 检测中国人基因组中HIV-1感染相关的特异性协同受体(CCR5)的基因多态性和比较提取人基因组DNA方法的优缺点。方法 我们分别用常规法和柱层析法从1219名中国人外周血PBMC中提取基因组DNA样品,对纯化后的DNA样品质量进行定性和定量分析;并对其基因组DNA中CCR5基因进行了PCR、Southern杂交和直接DNA测序等分析。结果 在中国人基因组中,检测的CCR5基因多态性是wt/wt 1 210例、wt/△32 3例,未检测到CCR5△32/△32纯合子突变,CCR5等位基因突变率为0.125%。常规法提取的基因组DNA所需的外周静脉血多(5ml);DNA的量较少且不稳定;操作步骤复杂。相反,QIAamp Boold Kit柱层析法提取DNA仅需要外周血200μl,可稳定地获得一定量的DNA,操作简便。结论 首次报道了中国人CCR5等位基因突变率是0.125%,提示我国绝大多数人群对嗜巨细胞HIV-1病毒的遗传易感性较高;同时证实试剂盒法提取的DNA更适合于CCR5基因多态性分析。  相似文献   

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