The Enhancing Effect of Microwave Irradiation and Ultrasonic Wave on the Recovery of Zinc Sulfide Ores

2017 ◽  
Vol 36 (6) ◽  
pp. 587-591
Author(s):  
Kun Yang ◽  
Libo Zhang ◽  
Chao Lv ◽  
Shiwei Li ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Zinc Sulfide ◽  
Ultrasonic Wave ◽  
Molar Ratio ◽  
Wave Power ◽  
Sulfide Ores ◽  
Reaction Energy ◽  
Liquid Ratio ◽  
Before And After ◽  
Total Ammonium ◽  
Xrd Patterns

AbstractA novel process for the treatment of zinc sulfide ores is discussed in this paper, which consists of two procedures: microwave roasting pretreatment and synergistic chelation. What’s more, the reaction mechanism also has been studied. By comparing XRD patterns before and after roasting, it can be concluded that microwave truly alleviates the reaction energy, and adding Na2O2 avoids the emission of SO2. % recovery of zinc can reaches 72.47 % on conditions of adding Na2O2 25 %, microwave activating temperature 500 °C, holding time 10 min, leaching temperature 40 °C, ultrasonic wave power 1,800 W, leaching time 4.5 h and solid to liquid ratio 10:1 in ammonium chloride solution whose total ammonium concentrate is 7.5 mol/L (c(NH3)T=7.5 mol/L). The molar ratio of NH4Cl and NH3·H2O is 1:1 (c(NH4Cl): c(NH3·H2O)=1:1). The effect of ultrasonic wave power in this process is to shorten reaction time.

Optimization of Combined Microwave-Ultrasonic Wave Extraction of Cochineal Dye by Response Surface Methodology

2012 ◽  
Vol 161 ◽  
pp. 82-87 ◽  
Author(s):  
Yuan Heng Guo ◽  
Hua Zheng ◽  
Hong Zhang ◽  
Li Yi Ma ◽  
Juan Han ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Optimal Condition ◽  
Response Surface ◽  
Ultrasonic Wave ◽  
Microwave Power ◽  
Wave Power ◽  
Single Factor ◽  
Liquid Ratio ◽  
Rsm Optimization ◽  
Dye Extraction

For more efficient and economical extraction of cochineal dye, combined microwave-ultrasonic wave extraction was applied. It was approached 4 factors as microwave power, treated time, materials-to-liquid ratio and ultrasonic wave power. Results showed that the optimal condition individually for cochineal dye extraction was at 400W microwave power, 17min treated time, 1:8 materials-to-liquid ratio and 600W ultrasonic wave power. On the basis of single factor test, RSM optimization of the extraction was achieved at 464W microwave power, 18.48min treated time, 1:8.23 materials-to-liquid ratio and 627W ultrasonic wave power. The verification was very approximate to the predicted value from the modelling regression equation. And the best extraction grade was tesified as 4 times.

scholarly journals Hydrothermally Assisted Fabrication of TiO2-Fe3O4 Composite Materials and Their Antibacterial Activity

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4715
Author(s):  
Adam Kubiak ◽  
Marta Kubacka ◽  
Elżbieta Gabała ◽  
Anna Dobrowolska ◽  
Karol Synoradzki ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Composite Materials ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Oxide Content ◽  
Gram Positive ◽  
Gram Negative ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Oxide Composites

The TiO2-Fe3O4 composite materials were fabricated via the hydrothermal-assisted technique. It was determined how the molar ratio of TiO2 to Fe3O4 influences the crystalline structure and morphology of the synthesized composite materials. The effect of the molar ratio of components on the antibacterial activity was also analyzed. On the basis of XRD patterns for the obtained titanium(IV) oxide-iron(II, III) oxide composites, the two separate crystalline forms—anatase and magnetite —were observed. Transmission electron microscopy revealed particles of cubic and tetragonal shape for TiO2 and spherical for Fe3O4. The results of low-temperature nitrogen sorption analysis indicated that an increase in the iron(II, III) oxide content leads to a decrease in the BET surface area. Moreover, the superparamagnetic properties of titanium(IV) oxide-iron(II, III) oxide composites should be noted. An important aim of the work was to determine the antibacterial activity of selected TiO2-Fe3O4 materials. For this purpose, two representative strains of bacteria, the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, were used. The titanium(IV) oxide-iron(II, III) oxide composites demonstrated a large zone of growth inhibition for both Gram-positive and Gram-negative bacteria. Moreover, it was found that the analyzed materials can be reused as antibacterial agents in three consecutive cycles with good results.

scholarly journals CHARACTERISTIC OF XONOTLITE SYNTHESIZED BY HYDROTHERMAL REACTION USING RICE HUSK ASH AND ITS APPLICATION TO ABSORB CHROME (III) SOLUTION

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Trung Kien Pham ◽  
Tran Ngo Quan
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Hydrothermal Reaction ◽  
Mekong Delta ◽  
Molar Ratio ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Xrf Scanning ◽  
Before And After ◽  
Chrome Iii

In this paper, we report on synthesizing xonotlite, calcium silicate hydrate (CSH), via a hydrothermal reaction using rice husk from the Mekong Delta, Vietnam. The rice husks were burnt at 1000 °C for 3 h. Grey rice husk ash was collected, then mixed with Ca(OH)2 at a Ca/Si molar ratio of 1 : 1. This was followed by a hydrothermal reaction at 180 °C for 24 h and 48 h to obtain the xonotlite mineral. Before and after adsorption, 3-mm xonotlite pellets were thoroughly characterized using X-ray diffractometry (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy. This material has potential application in chromium(III) removal during a chrome-plating process. The adsorption efficiency of the 3-mm pellet samples reached more than 76 % after 12 h.

scholarly journals MWCNTs/ZnO Nanofibers Fabrication, Properties and Applications

2019 ◽  
Vol 16 (1) ◽  
pp. 196-211
Author(s):  
Magda Dawy Badry
Keyword(s):  
Food Packaging ◽  
Fiber Diameter ◽  
Aluminum Foil ◽  
Hexagonal Wurtzite Structure ◽  
Organic Precursor ◽  
X Ray ◽  
Before And After ◽  
Zno Nanofibers ◽  
The Mean ◽  
Xrd Patterns

Electrospun MWCNTs nanofibers (CNF1, CNF2 and CNF3) with different concentrations of MWCNTs (0.3, 1.5, 2 wt%), respectively, were deposited on Aluminum foil substrates.  Also,Zinc AcetatedihydrateZn(CH3COO)2.2H2O (ZNF) and MWCNTs/zinc acetate (CZNF)nanofiberswere deposited on Aluminum foil substratesand annealed in the presence of oxygen at 400 oC. The resultant fibers were characterized using X-ray differaction (XRD), scanning electron microscope with energy dispersive X-Ray spectrophotometry (SEM,EDX), Fourier transform infrared (FTIR). SEM,EDX and FTIR exhibited a total decomposition of the organic precursor after calcination and formation of zinc oxide (ZONF and CZONF). The mean fiber diameter was found to be increased with increasing MWCNTs concentration and ranged 490-767 nm. XRD patterns indicated that ZnO was corundum with the hexagonal wurtzite structure. The crystallite size of ZONF and CZONF were determined by shurrer equation to be26 and  29.7  nm, respectively. The optical analysis indicated that the percentage transmittance increased after calcination.The band gap for the electrospun fibers before and after calcination was calculated. CZONF nanofibers have elec­trical properties similar to those of semiconductors. The testedcompounds CNF2, CNF3, CZNF and CZONF exhibited different activities against the bacteriaand yeast pathogen Candidaalbicans. CZNF compound is the most active against the bacteria and yeast pathogen. So, these compounds can be used as food packaging.  

scholarly journals Synthesis of Nanoscale Zerovalent Iron (nZVI) Supported on Biochar for Chromium Remediation from Aqueous Solution and Soil

2019 ◽  
Vol 16 (22) ◽  
pp. 4430 ◽  
Author(s):  
Haixia Wang ◽  
Mingliang Zhang ◽  
Hongyi Li
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
X Ray ◽  
Nanoscale Zerovalent Iron ◽  
Before And After ◽  
Pseudo Second Order ◽  
Xrd Patterns ◽  
Co Precipitation

Maize straw biochar-supported nanoscale zero-valent iron composite (MSB-nZVI) was prepared for efficient chromium (Cr) removal through alleviating the aggregation of zero-valent iron particles. The removal mechanism of MSB-nZVI was investigated by scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). Cr(VI) removal from aqueous solution by MSB-nZVI was greatly affected by pH and initial concentration. The removal efficiency of Cr(VI) decreased with increasing pH, and the removal kinetics followed the pseudo-second-order model. XRD patterns of MSB-nZVI before and after reaction showed that reduction and precipitation/co-precipitation (FeCr2O4, Fe3O4, Fe2O3) occurred with the conversion of Cr(VI) to Cr(III) and Fe(0) to Fe(II)/Fe(III). The produced precipitation/co-precipitation could be deposited on the MSB surface rather than being only coated on the surface of nZVI particles, which can alleviate passivation of nZVI. For remediation of Cr(VI)-contaminated saline–alkali soil (pH 8.6–9.0, Cr 341 mg/kg), the released amount of Cr(VI) was 70.7 mg/kg, while it sharply decreased to 0.6–1.7 mg/kg at pH 4.0–8.0, indicating that the saline–alkali environment inhibited the remediation efficiency. These results show that MSB-nZVI can be used as an effective material for Cr(VI) removal from aqueous solution and contaminated soil.

scholarly journals Aerosolizable Lipid Nanoparticles for Pulmonary Delivery of mRNA through Design of Experiments

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1042
Author(s):  
Hairui Zhang ◽  
Jasmim Leal ◽  
Melissa R. Soto ◽  
Hugh D. C. Smyth ◽  
Debadyuti Ghosh
Keyword(s):  
Design Of Experiments ◽  
Protein Expression ◽  
Messenger Rna ◽  
Pulmonary Delivery ◽  
Lipid Nanoparticles ◽  
In Vivo Studies ◽  
Molar Ratio ◽  
Mouse Lung ◽  
Intracellular Protein ◽  
Before And After

Messenger RNA is a class of promising nucleic acid therapeutics to treat a variety of diseases, including genetic diseases. The development of a stable and efficacious mRNA pulmonary delivery system would enable high therapeutic concentrations locally in the lungs to improve efficacy and limit potential toxicities. In this study, we employed a Design of Experiments (DOE) strategy to screen a library of lipid nanoparticle compositions to identify formulations possessing high potency both before and after aerosolization. Lipid nanoparticles (LNPs) showed stable physicochemical properties for at least 14 days of storage at 4 °C, and most formulations exhibited high encapsulation efficiencies greater than 80%. Generally, upon nebulization, LNP formulations showed increased particle size and decreased encapsulation efficiencies. An increasing molar ratio of poly-(ethylene) glycol (PEG)-lipid significantly decreased size but also intracellular protein expression of mRNA. We identified four formulations possessing higher intracellular protein expression ability in vitro even after aerosolization which were then assessed in in vivo studies. It was found that luciferase protein was predominately expressed in the mouse lung for the four lead formulations before and after nebulization. This study demonstrated that LNPs hold promise to be applied for aerosolization-mediated pulmonary mRNA delivery.

scholarly journals Potential Sustainable Slow-Release Fertilizers Obtained by Mechanochemical Activation of MgAl and MgFe Layered Double Hydroxides and K2HPO4

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 183 ◽  
Author(s):  
Roger Borges ◽  
Fernando Wypych ◽  
Elodie Petit ◽  
Claude Forano ◽  
Vanessa Prevot
Keyword(s):  
Layered Double Hydroxides ◽  
Slow Release ◽  
Mechanochemical Activation ◽  
Molar Ratio ◽  
X Ray ◽  
Dipotassium Hydrogen Phosphate ◽  
Before And After ◽  
Noticeable Improvement ◽  
Slow Release Fertilizers ◽  
Double Hydroxides

This study describes the behavior of potential slow-release fertilizers (SRF), prepared by the mechanochemical activation of calcined Mg2Al-CO3 or Mg2Fe-CO3 layered double hydroxides (LDH) mixed with dipotassium hydrogen phosphate (K2HPO4). The effects of LDH thermal treatment on P/K release behavior were investigated. Characterizations of the inorganic composites before and after release experiments combined X-Ray diffraction (XRD), Fourier-transform infra-red spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The best release profile (<75% in 28 days and at least 75% release) was obtained for MgAl/K2HPO4 (9 h milling, 2:1 molar ratio, MR). Compared to readily used K2HPO4, milling orthophosphate into LDH matrices decreases its solubility and slows down its release, with 60% and 5.4% release after 168 h for MgAl/K2HPO4 and MgFe/K2HPO4 composites, respectively. Mechanochemical addition of carboxymethylcellulose to the LDH/K2HPO4 composites leads to a noticeable improvement of P release properties.

scholarly journals Synthesis of Pyrazolone Derivatives and Their Nanometer Ag(I) Complexes and Physicochemical, DNA Binding, Antitumor, and Theoretical Implementations

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Ismail Althagafi ◽  
Nashwa M. El-Metwaly ◽  
Marwa G. Elghalban ◽  
Thoraya A. Farghaly ◽  
Abdalla M. Khedr
Keyword(s):  
High Efficiency ◽  
Carcinoma Cell ◽  
Kinetic Studies ◽  
Molar Ratio ◽  
Breast Carcinoma Cell Line ◽  
Practical Result ◽  
Carcinoma Cell Lines ◽  
Pyrazolone Derivatives ◽  
Xrd Patterns ◽  
Mcf 7

Four pyrazolone derivatives and their corresponding silver complexes were synthesized and characterized. Based on elemental analysis, 1 : 2 (M : L) molar ratio was suggested for all inspected complexes. 1H, 13C NMR, mass, UV-Vis, TGA, and IR were the spectral tools used for describing the formulae. Moreover, XRD patterns and SEM pictures were used to evaluate the particle sizes which appeared strongly in nanometer range. CT-DNA study is the major consideration in this study, to test the interacting ability of all synthesized cationic complexes towards cell DNA. Each binding constant was computed and correlated with the Hammett sigma constant. Antitumor activity was examined upon three carcinoma cell lines (MCF-7, HepG2, and HCT116). The high efficiency was recorded towards MCF-7 (breast carcinoma) cell line. Kinetic studies yield essential parameters to assert on the rule of metal atom on thermal feature of organic compounds. Molecular modeling was implemented to optimize the structures of compounds. Also, molecular docking was achieved to obtain a clear view about proposed drug behavior within the affected cells. This was achieved through comparing the calculated internal energy values of all docking complexes. All the tested compounds displayed a significant interaction with breast cancer protein (strong matching with practical result) followed by DNA polymerase protein.

Synthesis and Thermoelectric Studies in Cr Doped Cobalt Ferrites Nano Particles

2012 ◽  
Vol 510-511 ◽  
pp. 171-176 ◽  
Author(s):  
M. Anis-ur-Rehman ◽  
Mariam Ansari ◽  
Zeb Un Nisa Mughal ◽  
M.S. Awan ◽  
Ashari Maqsood
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Room Temperature ◽  
Nano Particles ◽  
Power Measurement ◽  
Cobalt Ferrites ◽  
Before And After ◽  
Crystallite Sizes ◽  
Xrd Patterns ◽  
Co Precipitation

Samples of Cr doped cobalt ferrite were prepared by co-precipitation route. These particles were characterized by X-ray diffraction (XRD) at room temperature. The structural properties were observed before and after sintering. The FCC spinel structure was confirmed by XRD patterns of the samples. The crystallite sizes lie in the range of 37-60 nm. DC electrical properties as a function composition were measured. Scanning electron microscopy was used in order to investigate the surface morphology of the prepared samples. The system for thermoelectric power measurement was designed, developed and calibrated in the laboratory. The room temperature thermoelectric power was measured for the prepared samples. The magnitude of Seebeck coefficient depends on the composition and resistivity of the samples. The obtained values of Seebeck coefficient for CoFe2O4are in good agreement to the reported values. Determined values of Seebeck coefficient for other studied compositions are an addition to the literature.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

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