Facile decoration of TiO2 nanoparticles on graphene for solar degradation of organic dye

The reduced graphene oxide is interesting material for the synthesis of TiO₂-based photocatalyst. In the present investigation, blackberry fruit, which contains high levels of anthocyanins and other phenolic compounds, was employed as a reducing agent mainly due to its high antioxidant capacity. The nano-crystalline TiO₂ was decorated on different amounts of graphene oxide with sol–gel method and then the photocatalytic activity for degradation of cationic dye was evaluated by UV spectroscopy to achieve the optimum content of graphene oxide. The decoration of anatase nanoparticles on prepared reduced graphene oxide was investigated by X-ray diffraction, scanning and transmission electron microscopy techniques. The new composite gives significantly higher activity when is compared to the compositions fabricated by graphene oxide. The compact layer provides a large TiO₂-graphene contact area and reduces the electron recombination. The decoration of TiO₂ nanoparticles, 5–10 nm, on the graphene oxide reduced by blackberry juice further improves the dye removal. The results imply that the nanoparticle decoration is the key strategy to increase the degradation capacity.     

Water as a green solvent combined with different techniques for extraction of essential oil from lavender flowers

Using water as a green solvent with a variable geometry makes use of physical and chemical phenomena that are fundamentally different from those applied in conventional extraction techniques such as hydro-distillation, steam distillation or solvent extraction. Advantages and drawbacks of using water as a solvent with different physical and chemical states have been compared. A total of ten extraction techniques: hydro-distillation (HD), steam distillation (SD), turbo-hydro-distillation (THD), salt-hydro-distillation (NaCL-HD), enzyme-hydro-distillation (Enzyme-HD), micelle-hydro-distillation (Micelle-HD), ultrasound-hydro-distillation (US-HD) or subcritical water-hydro-distillation (SW-HD), solvent-free microwave extraction (SFME) and microwave steam distillation (MSD) were used to extract the essential oil from lavender (Lavandula L.) and their results were compared. The quantity was measured by the yield of essential oil and the quality was evaluated using the oil composition especially the content of linalyl acetate, linalool and terpin-4-ol compared with the corresponding control sample: Hydro-distillation. For environmentally friendly of the process: extraction time, total energy consumption and CO₂ emission were considered and compared with conventional hydro-distillation. The mechanism explaining the linalyl acetate degradation has been resolved by using COSMO-RS software. Based on the present experimental conditions, it is recommended that lavender oil may be produced preferably by steam distillation assisted by microwave extraction to reduce the by-product formation by various chemical reactions and to get better oil recoveries.     

Development of deep eutectic solvents applied in extraction and separation

Deep eutectic solvents, as an alternative to ionic liquids, have greener credentials than ionic liquids, and have attracted considerable attention in related chemical research. Deep eutectic solvents have attracted increasing attention in chemistry for the extraction and separation of various target compounds from natural products. This review highlights the preparation of deep eutectic solvents, unique properties of deep eutectic solvents, and synthesis of deep‐eutectic‐solvent‐based materials. On the other hand, application in the extraction and separation of deep eutectic solvents is also included in this report. In this paper, the available data and references in this field are reviewed to summarize the applications and developments of deep eutectic solvents. Based on the development of deep eutectic solvents, an exploitation of new deep eutectic solvents and deep eutectic solvents‐based materials is expected to diversify into extraction and separation.     

Ultrasound induced green solvent extraction of oil from oleaginous seeds

Ultrasound-assisted extraction of rapeseed oil was investigated and compared with conventional extraction for energy efficiency, throughput time, extraction yield, cleanness, processing cost and product quality. A multivariate study enabled us to define optimal parameters (7.7 W/cm² for ultrasonic power intensity, 40 °C for processing temperature, and a solid/liquid ratio of 1/15) for ultrasound-assisted extraction of oil from oilseeds to maximize lipid yield while reducing solvent consumption and extraction time using response surface methodology (RSM) with a three-variable central composite design (CCD). A significant difference in oil quality was noted under the conditions of the initial ultrasound extraction, which was later avoided using ultrasound in the absence of oxygen. Three concepts of multistage cross-current extraction were investigated and compared: conventional multistage maceration, ultrasound-assisted maceration and a combination, to assess the positive impact of using ultrasound on the seed oil extraction process. The study concludes that ultrasound-assisted extraction of oil is likely to reduce both economic and ecological impacts of the process in the fat and oil industry.     

Synergy of Cu/C3N4 Interface and Cu Nanoparticles Dual Catalytic Regions in Electrolysis of CO to Acetic Acid

Electrochemical reduction reaction of carbon monoxide (CORR) offers a promising way to manufacture acetic acid directly from gaseous CO and water at mild condition. Herein, we discovered that the graphitic carbon nitride (g-C₃N₄) supported Cu nanoparticles (Cu−CN) with the appropriate size showed a high acetate faradaic efficiency of 62.8 % with a partial current density of 188 mA cm⁻² in CORR. In situ experimental and density functional theory calculation studies revealed that the Cu/C₃N₄ interface and metallic Cu surface synergistically promoted CORR into acetic acid. The generation of pivotal intermediate −*CHO is advantage around the Cu/C₃N₄ interface and migrated *CHO facilitates acetic acid generation on metallic Cu surface with promoted *CHO coverage. Moreover, continuous production of acetic acid aqueous solution was achieved in a porous solid electrolyte reactor, indicating the great potential of Cu−CN catalyst in the industrial application.     

Bifunctional Onium and Potassium Iodides as Nucleophilic Catalysts for the Solvent-Free Syntheses of Carbonates,Thiocarbonates, and Oxazolidinones from Epoxides

The catalytic potential of organo-onium iodides as nucleophilic catalysts is aptly demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO₂), as a representative CO₂ utilization reaction. Although organo-onium iodide nucleophilic catalysts are metal-free environmentally benign catalysts, harsh reaction conditions are generally required to efficiently promote the coupling reactions of epoxides and CO₂. To solve this problem and accomplish efficient CO₂ utilization reactions under mild conditions, bifunctional onium iodide nucleophilic catalysts bearing a hydrogen bond donor moiety were developed by our research group. Based on the successful bifunctional design of the onium iodide catalysts, nucleophilic catalysis using a potassium iodide (KI)-tetraethylene glycol complex was also investigated in coupling reactions of epoxides and CO₂ under mild reaction conditions. These effective bifunctional onium and potassium iodide nucleophilic catalysts were applied to the solvent-free syntheses of 2-oxazolidinones and cyclic thiocarbonates from epoxides.     

Effectiveness of pressurized liquid extraction and solvent extraction for the simultaneous quantification of 14 pesticide residues in green tea using GC

A simultaneous multiresidue method to determine 14 different pesticides, namely: flufenoxuron, fenitrothion, chlorfluazuron, chlorpyrifos, hexythiazox, methidathion, chlorfenapyr, tebuconazole, EPN, bifenthrin, cyhalothrin, spirodiclofen, difenoconazole, and azoxystrobin in green tea using pressurized liquid extraction (PLE) is described and compared with that of liquid-liquid extraction (LLE). For PLE, the extraction conditions were not optimized. Rather they were selected based upon previous successful investigations published by our laboratory. Analysis was performed by GC with electron capture detector (GC-ECD), and the pesticide identity of the positive samples was confirmed by GC-MS in a selected ion-monitoring (SIM) mode. Calibration curves showed an excellent linearity for concentrations ranging from 0.006 to 36.049 ppm, with r(2) >0.995. Green tea spiked at each of the two fortification levels, yielded average recoveries in the range of 87-112% and 71-109% for PLE and LLE, respectively. Precision values, expressed as RSDs, were below 6% at various spiking levels. With respect to the existing procedures, both methods gave LOQs that were lower than the maximum residue limits (MRLs) established by the Korea Food and Drug Administration (KFDA). Both methods have been successfully applied to the analysis of real samples, and bifenthrin was the only pesticide residue quantified in incurred green tea samples, with concentrations ranging from 0.093 ppm (LLE) to 0.1 ppm (PLE). These concentration levels were relatively low compared to KFDA-MRL (0.3 ppm). According to the validation data and performance characteristics, both methods are appropriate for multiresidue analysis of pesticide residues in green tea. PLE methodology showed superiority in recoveries of some pesticides, acceptable accuracy and precision while minimizing environmental concerns, time, and labor, and can be applied in routine analytical laboratories.     

Removable singularities of solutions of linear uniformly elliptic second order equations

Let L be a uniformly elliptic linear second order differential operator in divergence form with bounded measurable real coefficients in a bounded domain G ? ?ⁿ (n ? 2). We define classes of continuous functions in G that contain generalized solutions of the equation L? = 0 and have the property that the compact sets removable for such solutions in these classes can be completely described in terms of Hausdorff measures.     

On commuting polynomial automorphisms of {\mathbb{C}}^{k} , k ≥ 3

We characterize the polynomial automorphisms of ${\mathbb{C}}^3We characterize the polynomial automorphisms of , which commute with a regular automorphism. We use their meromorphic extension to and consider their dynamics on the hyperplane at infinity. We conjecture the additional hypothesis under which the same characterization is true in all dimensions. We give a partial answer to a question of S. Smale that in our context can be formulated as follows: can any polynomial automorphism of be the uniform limit on compact sets of polynomial automorphisms with trivial centralizer (i.e. )? Partially supported by Progetto MURST di Rilevante Interesse Nazionale Proprietà geometriche delle varietà reali e complesse. Supported by Istituto Nazionale Alta Matematica, “F. Severi”, Roma and G.N.S.A.G.A., Roma.     

A review on bio-lubricants from non-edible oils-recent advances,chemical modifications and applications

The necessity for lubricants has increased recently, and today's chief issue is the depletion of fossil resources, which drives up the cost of lubricants made of petroleum. As a result, current research focuses on lubricants that are made from renewable resources and are therefore environmentally benign. We can use inedible plant oils as the foundation for biodegradable bio lubricants. The locally accessible seed oils have significant uses in agriculture and nutrition, but more recently, their use in biolubricants and chemical feedstocks has increased. They are favourable to mineral-based counterparts and prospective commodities because of their unique qualities, such as lubricity, biodegradability, reduced toxicity, and reduced volatility. However, while being chemically altered, they still have rather poor cold-flow and thermo-oxidative stability concerns, which restricts their use as lubricants. To get around this restriction, numerous chemical changes have been documented, including transesterification, epoxidation, and estolide ester synthesis, all of which are covered in this paper. The current state and anticipated future trends of the global lubricant market are presented in this review. The primary goal of the current study is to provide an overview of recent non-edible plant uses in biolubricant synthesis. This study contains a review of recent research literature on the utilisation of various non-edible plant oils to create biolubricants.