Synthesis of Mesoporous Lanthanum Phosphate and Its Use as a Novel Sorbent

Mesoporous lanthanum phosphate was synthesized by supramolecular self-assembly of cetyltrimethylammo-nium bromide and lanthanum nitrate following digestion in phosphoric acid.TGA-DTA,XRD and SEM were em-ployed to study the uncalcined and calcined materials.Sorption behavior of Cr(Ⅲ),Mn(Ⅱ),Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ba(Ⅱ),Hg(Ⅱ)and Pb(Ⅱ)cations was studied on such materials in water,3 mol·L~(-1)ammonia,0.01 mol.L~(-1)potassium ferrocyanide and 0.01 mol·L~(-1)potassium ferricyanide solutions.     

A Freeze Dried Kit for 99mTc(V) Dimercaptosuccinic Acid

^99mTc pentavalent dimercaptosuccinic acid [^99mTc(V) DMSA], a useful agent for imaging thyroid medullary carcinoma and other tumors can be reliably prepared by addition of Na^99mTcO₄ to a freeze-dried mixture of DMSA and Sn (2:1 molar ratio). The radiochemical purity, stability and animal bio-distribution behaviour is similar to that of the agent made by addition of NaHCO₃ to DMSA (III) renal imaging freeze-dried kit.     

Investigating the Influence of Column Depth on the Treatment of Textile Wastewater Using Natural Zeolite

Textile industry production processes generate one of the most highly polluted wastewaters in the world. Unfortunately, the field is also challenged by the availability of relatively cheap and highly effective technologies for wastewater purification. The application of natural zeolite as a depth filter offers an alternative and potential approach for textile wastewater treatment. The performance of a depth filter treatment system can be deeply affected by the column depth and the characteristics of the wastewater to be treated. Regrettably, the information on the potential of these filter materials for the purification of textile wastewater is still scarce. Therefore, this study investigated the potential applicability of natural zeolite in terms of column depth for the treatment of textile wastewater. From the analysis results, it was observed that the filtration efficiencies were relatively low (6.1 to 13.7%) for some parameters such as total dissolved solids, electrical conductivity, chemical oxygen demand, and sodium chloride when the wastewater samples were subjected to the 0.5 m column depth. Relatively high efficiency of 82 and 93.8% was observed from color and total suspended solids, respectively, when the wastewater samples were subjected to the 0.5 m column depth. Generally, the 0.75 m column depth achieved removal efficiencies ranging from 52.3% to 97.5%, whereas the 1 m column depth achieved removal efficiencies ranging from 86.9% to 99.4%. The highest removal efficiency was achieved with a combination of total suspended solids and 1 m column depth (99.4%). In summary, the treatment approach was observed to be highly effective for the removal of total suspended solids, with a 93.8% removal efficiency when the wastewater was subjected to the 0.5 m column depth, 97.5% for 0.75 m column depth, and 99.4% for 1 m column depth. Moreover, up to 218.233 mg of color per g of the filter material was captured. The results derived in this study provide useful information towards the potential applicability of natural zeolite in the textile wastewater treatment field.     

Flow and heat transfer of nanofluid past stretching/shrinking sheet with partial slip boundary conditions

The boundary layer flow of a nanofluid past a stretching/shrinking sheet with hydrodynamic and thermal slip boundary conditions is studied. Numerical solutions to the governing equations are obtained using a shooting method. The results are found for the skin friction coefficient, the local Nusselt number, and the local Sherwood number as well as the velocity, temperature, and concentration profiles for some values of the velocity slip parameter, thermal slip parameter, stretching/shrinking parameter, thermophoresis parameter, and Brownian motion parameter. The results show that the local Nusselt number, which represents the heat transfer rate, is lower for higher values of thermal slip parameter, thermophoresis parameter, and Brownian motion parameter.     

Formal synthesis of J-type prostaglandins based on enantiopure polyfunctional cyclopentenol derivative

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Evaluation of process conditions and characterization of particle size and stability of oil-in-water nanoemulsions

This article reports on the oil in water (o/w) nanoemulsions, which were prepared using a mixture of solvents (decane, toluene and cyclohexane) as oils and the mixtures of ethoxylated lauryl alcohols with various concentrations as surfactants with HLB values ranged from 10 to 12. The Ultra-Turrax (rotor-stator type) stirring and/or ultrasound processing were applied for varied processing times. The data show that the particle sizes in nanoemulsions prepared with ultrasound were smaller than those produced by stirring. The stability of these emulsions was, however, enhanced, when the mixtures were preliminary processed with the shearing agitator. The most stable nanoemulsions were obtained in 10 wt % surfactant mixture of the alcohols with HLB 11 in the shearing agitator.     

Tunable emission of AgIn5S8 and ZnAgIn5S8 nanocrystals: electrosynthesis,characterization and optical application

Ternary AgIn₅S₈ (AIS) and quaternary ZnAgIn₅S₈-alloy (ZAIS) nanocrystals, stabilized by L-glutathione, were produced by a clean and eco-friendly electrochemical method, eliminating the need of reducing agents. AIS-GSH colloidal solution was obtained by constant current electrolysis (i = 30 mA) in cavity cell. S^2? ions (0.051 mmol) were generated into a graphite powder macroelectrode, reacting in the intermediate compartment of the cell containing Ag⁺/In³⁺ aqueous solution at different ratios (0.5, 0.28, 0.18, and 0.14), and 0.025 mmol/L^?1 glutathione (GSH). ZAIS-GSH NCs were synthesized in the same cavity cell containing the previously prepared AIS-GSH solution. A paired electrolysis (i = 30 mA) was used for simultaneous production of Zn²⁺ and S^2? (Zn⁰ sacrificial anode and graphite powder macroelectrode/S⁰ cathode). The electrochemical method promoted a high reproducibility and efficient luminescence in the preparations of NCs. The sizes of the AIS-GSH and ZAIS-GSH nanoparticles were determined by HRTM (3.4 and 4.0 nm, respectively), and quantum yields reaching 16% (AIS-GSH, Ag⁺/In³⁺ = 0.18). The spectrophotometric characterization showed that Ag⁺/In³⁺ ratio can be used for the tuning of the AIS-GSH nanoparticle emission wavelength, which is associated to electronic defects introduced in the NCs lattice. XRD/EDS analysis of ZAIS-GSH nanoparticles point out to Zn²⁺ ion-exchange into the AIS-GSH lattice. XPS analysis was carried out at different etching levels of the ZAIS nanocrystals surface, making possible to identify the 2p Zn doublet signal, indicating two different Zn²⁺ sites in the alloy structure. Time-resolved spectroscopy measurements/decay curves were carried out to evaluate the effect of silver amount on radioactive and non-radioactive terms. Additionally, the AIS-GSH and ZAIS-GSH photoluminescence and stability were used to produce the active parts of commercial white LEDs, and modulate the colour perception from the respective emission bands.     

Particle size dependence of the Pr2Fe17 nitrogenation process

The particle size dependence of the Pr₂Fe₁₇ nitrogenation process at 400°C is determined by the Mössbauer method. The experimental data are described in terms of a particle model consisting of spherical concentrical shells containing: (i) an expanded central core saturated with 2+ atoms N per formula unit; (ii) an intermediate unnitrided shell with a volume larger than the core by a factor of about 2.4 and accommodating a stress/strain field produced by the expanded core, and (iii) an unnitrogenated undeformed external shell. We observed that small particles (d 10 m and most probably lower) tend to absorb higher nitrogen contents than the large ones. Our results also indicate that some small particles, most probably single crystals, do not nitrogenate.     

Calorimetry and thermogravimetry as tools for the assessment of the thermal stability of polyoxide-based nonionic surfactants

Differential scanning calorimetry (DSC) and thermogravimetry (TGA) have been used to evaluate the thermal stability of nonionic surfactants. We have studied monofunctional diblock copolymers of poly(ethylene oxide-propylene oxide) (R-PEO–PPO–OH, where R length is linear C₄ or C_12–14) as nonionic surfactants. It was observed that the thermal stability was dependent on the copolymer structure. Moreover, the higher the EO/PO ratio in the copolymers the higher the oxidative thermal stability. The autoxidation exhibits exothermic behaviour and the enthalpy related to the process depends on the EO/PO ratio. The initial temperatures of degradation obtained from DSC and TGA were in agreement.