Facile Synthesis of CuO and Ag Nanoparticles by Thermal Decomposition of Novel Schiff Base Complexes

Journal of Inorganic and Organometallic Polymers and Materials - In this paper, a new Schiff base was synthesized via the condensation reaction between 3-methyl-4-amino-5-mercapto-1,2,4 triazole...     

Production of mixed methyl/ethyl esters from waste fish oil through transesterification with mixed methanol/ethanol system

Biodiesel (mixed fatty acid methyl/ethyl esters) was prepared from waste fish oil through base-catalyzed transesterification with mixed methanol/ethanol system. Effect of methanol/ethanol (% v/v), type and concentration of the catalyst, mixed alcohols to oil molar ratio, the reaction temperature, and the reaction time on the biodiesel yield was optimized. Maximum biodiesel yield (97.30?wt%) was produced by implementing 1:1 methanol/ethanol (v/v), 1.0?wt% KOH, 6:1 mixed alcohols to oil molar ratio, 40°C reaction temperature, and 30?min of reaction time. Conversion of the waste fish oil to mixed methyl/ethyl esters was confirmed by ¹H NMR spectroscopy. Fuel properties of the resulting biodiesel in addition to its blends with petrodiesel were in good agreement with specifications of ASTM D6751 and ASTM D7467, respectively. Therefore, it was concluded that using mixed alcohol system for biodiesel production could reduce the production cost through reducing conditions required for maximum conversion.     

Process design of waste gas treatment from Emirates Gold Refinery

In this case study, the process modifications and improvement to the existing process at the Emirates Gold refinery (in order to meet the United Arab Emirates (UAE) nitrogen oxides air emission regulations) is presented. In the past, Emirates Gold refinery used a single small scrubber to treat waste gases. In order to treat the waste gas efficiently, it was found that a cooled oxidation reactor (oxidizer) before the existing scrubber, as well as a second scrubber is needed. The waste gas is mixed with air at a fixed ratio before entering the oxidizer which is designed to obtain the optimum degree of NO oxidation (about 50%).To keep the oxidation reactions in the desirable direction the temperature should be kept between 15 and 20°C There for an internal cooler was required. The gas mixture from the Oxidizer enters the first scrubber (existing) where most of the NO _x , mainly as N₂O₃, are absorbed by a NaOH solution (15–20%). The remaining NO _x , mainly as N₂O₃ is absorbed in the second scrubber by a NaOH solution (8–10%). The mass transfer area of the packing in the two scrubbers, the solution circulation rate, and the cooling duty were designed to reach the desired degree of absorption of N₂O₃ and NO₂. This ensures that the recommended NO _x residual value of 500 mg/m³ (250 ppm) is reached. All reactions occur simultaneously was calculated using EQ4WIN software. The data obtained for different temperatures was processed with Stat View, SuperPro Designer simulation and Aspen HYSYS simulation.     

Improving arteriovenous fistula rate: Effect on hemodialysis quality

Vascular access (VA) is the lifeline for patients with end‐stage renal disease on regular hemodialysis (HD). Tunneled catheters have been associated with increased risk of luminal thrombosis, infection, hospitalization, and high cost. Our aims were to follow the “Fistula First Initiative,” avoid or reduce the rate of catheter insertion, improve the rate of arteriovenous fistula (AVF) use, and study the effect of increased AVF use on quality of dialysis and patient's outcome. A VA program has been established in collaboration with an enthusiastic and professional vascular surgery team to manage 358 patients who have been on regular HD treatment for a period ranging from 1 to 252 months. The mean ± standard deviation age of patients was 52 ± 15 years with 62% male patients. Over a period of 2 years, 408 procedures were performed. These include 293 AVFs and 56 arteriovenous grafts (AVGs). Other procedures include 39 permanent catheter insertions, 8 AVF aneurysmectomy, removal of 6 AVGs, embolectomy of 4 AVGs, excision of 1 AVG lymphocele, and ligation of 1 AVF. This program resulted in significant increase in AVF rate from 35% to 82%; reduction in catheter rate from 62% to 10.9%; infection rate down from 6.6% to 0.6%; VA clotting down from 5.1% to 1.0%; and increase in average blood flow rate from 214 ± 32 to 298 ± 37 mL/min (P < 0.01). These results have been associated with improved average single pool Kt/V from 0.88 ± 0.19 to 1.28 ± 0.2 (P < 0.01); increased hemoglobin from 9.2 ± 1.2 to 10.9 ± 0.9 g/dL (P < 0.01); improved serum albumin from 3.2 ± 0.5 to 3.7 ± 0.4 g/dL (P < 0.05); reduction in administered erythropoietin dose by 19%; and significant drop in hospitalization rate from 6.1% to 3.8%. These results confirm the great benefits of AVF on quality of HD and patient outcome, and clearly affirm that AVF should always be considered first.     

Importance of GLUT Transporters in Disease Diagnosis and Treatment

Facilitative sugar transporters (GLUTs) are the primary method of sugar uptake in all mammalian cells. There are 14 different types of those transmembrane proteins, but they transport only a handful of substrates, mainly glucose and fructose. This overlap and redundancy contradict the natural tendency of cells to conserve energy and resources, and has led researchers to hypothesize that different GLUTs partake in more metabolic roles than just sugar transport into cells. Understanding those roles will lead to better therapeutics for a wide variety of diseases and disorders. In this review we highlight recent discoveries of the role GLUTs play in different diseases and disease treatments.     

Self-Assembled Microactuators Using Chiral Liquid Crystal Elastomers

Materials that undergo reversible changes in form typically require top-down processing to program the microstructure of the material. As a result, it is difficult to program microscale, 3D shape-morphing materials that undergo non-uniaxial deformations. Here, a simple bottom-up fabrication approach to prepare bending microactuators is described. Spontaneous self-assembly of liquid crystal (LC) monomers with controlled chirality within 3D micromold results in a change in molecular orientation across thickness of the microstructure. As a result, heating induces bending in these microactuators. The concentration of chiral dopant is varied to adjust the chirality of the monomer mixture. Liquid crystal elastomer (LCE) microactuators doped with 0.05 wt% of chiral dopant produce needle-shaped actuators that bend from flat to an angle of 27.2 ± 11.3° at 180 °C. Higher concentrations of chiral dopant lead to actuators with reduced bending, and lower concentrations of chiral dopant lead to actuators with poorly controlled bending. Asymmetric molecular alignment inside 3D structure is confirmed by sectioning actuators. Arrays of microactuators that all bend in the same direction can be fabricated if symmetry of geometry of the microstructure is broken. It is envisioned that the new platform to synthesize microstructures can further be applied in soft robotics and biomedical devices.     

Electric vehicle battery charging framework using artificial intelligence modeling of a small wind turbine based on experimental characterization

The objective of this paper is to develop a generic electric vehicle battery charging framework using wind energy as the direct energy source. A robust model for a small vertical axis wind turbine based on an artificial neural network algorithm is used for predicting its performance over a wide range of operating conditions. The proposed framework can be implemented at any location worldwide where full prediction of the wind signature is perfectly obtained. In this paper, a small vertical axis wind turbine has been experimentally characterized at different operating conditions, where measured data, output power, and torque have been used to build the model. Once the model has been developed, the model is inserted into the MATLAB/Simulink software tool to predict the charging performance of a battery for an electric vehicle. An rpm controller has been used to achieve the maximum generated power from the wind turbine across the day with various wind speeds. Hence, the generated power is fed to the EV battery charger to implement the constant current constant voltage charging protocol. The charging current reached the desired value in a settling time of 4.5 s, whatever the intermittency of the wind energy. The proposed application of wind energy to EV provides sufficient constant power supported by the utility grid.

Graphical Abstract

     

Design and Analysis of Charge-Reduced Refrigerant Cycles Using R290

R290 is one of the most promising refrigerants for heat pumps and cooling processes working in a temperature range of –15 to 70 °C. The nearly neglectable global warming potential and attractive thermodynamic properties allow the design of climate-friendly and efficient refrigeration systems and heat pumps. However, R290 is flammable, and the use of charge-reduced components and designs should be the first central step to reduce safety risks. Whereas the prediction of heat capacity, temperatures and pressure drops are sufficiently precise the prediction of refrigerant charge is not very accurate when using computer-aided design tools. The article presents a method to enhance accuracy for refrigerant cycles with less than 500 g of R290.