Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@SiO<Subscript>2</Subscript>@TiO<Subscript>2</Subscript>-OSO<Subscript>3</Subscript>H: an efficient hierarchical nanocatalyst for the organic quinazolines syntheses

A sulfonic acid functionalized titanium dioxide quasi-superparamagnetic nanocatalyst Fe₃O₄@SiO₂@TiO₂-OSO₃H with average size of 61 nm and semispherical shape with surface area about 97 m² g^?1 with saturation magnetization 17.7 emu g^?1 and the coercivity 9.84 Oe was successfully synthesized. The structure and morphology of the nanocatalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy, X-ray diffraction pattern, transmission electron microscopy, field-emission scanning electron microscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller surface area analysis. The catalytic usage of the nanocatalyst was exemplified in synthesis of 2,3-dihydroquinazolin-4(1H)-one and spiroquinazolin-4(3H)-one derivatives in deep eutectic solvents (DESs) based on choline chloride and urea. We suggest that the synergistic effects in catalytic activities of titanium dioxide, organic acid and the CO₂ capture property of DES are the main reasons for the improvement of catalytic activity. The synthesized spiroquinazolinones and dihydroquinazolinones derivatives were characterized by FT-IR, ¹H and ¹³C nuclear magnetic resonance spectroscopy. The magnetic nanocatalyst exhibit high catalytic activity and can be simply separated from reaction media by an external magnet in a few seconds and could be reused for six cycles without significant loos in activity, which indicates the good immobilization of sulfonic acid on the magnetic titanium dioxide support. Furthermore, the solvent which has been used in this work can be readily isolated and reused for several times.     

Does weather explain cost and quality performance? An analysis of UK electricity distribution companies

In recent years, a number of empirical studies and energy regulators have applied benchmarking techniques to measuring the efficiency and performance of network utilities. An important issue has been the extent to which the results are influenced by contextual factors. Among these, weather factors are frequently discussed as being important. We use factor analysis and two-stage data envelopment analysis techniques to examine the effect of a set of important weather factors (gale, hail, temperatures, rainfall and thunder) on the performance of electricity distribution networks in the UK. The results indicate that such factors often do not have a significant economic and statistical effect on the overall performance of the utilities. The weather parameters in some models are significant in terms of economic efficiency. The results echo our previous findings of the importance of extending the basic model to include other inputs such as total expenditure (Totex), customer minutes lost (CML) and network energy losses in regulatory benchmarking.     

Effect of chitosan edible coating enriched with lemon verbena extract and essential oil on the shelf life of vacuum rainbow trout (Oncorhynchus mykiss)

In this research, the antioxidant and antibacterial characteristics of the chitosan (CH) coating incorporated with lemon verbena essential oil (LVEO) and extract (LVE) on the quality of the rainbow trout packed by vacuum packaging at 4°C were investigated. Samples evaluated include the following: Control, VP, CH, CH-LVE 2%, CH-LVEO 1%, and CH-LVE 1%-LVEO 0.5% for 16 days at 3 days intervals. All of the samples significantly reduced Psychrotrophic bacteria, total viable counts, Enterobacteriaceae, and H₂S producing bacteria as compared with control during keeping time. Thiobarbituric acid reactive substance, peroxide value, total volatile basic nitrogen, and pH value were detected lower in all of the samples than control. CH incorporated with LVE and LVEO gave an agreeable effect on sensory characteristics. Samples containing CH-LVE 1%-LVEO 0.5% was often in priority by sensory assessors. Generally, LV can be applied as a substitution for chemical preservatives in fish meat.     

Thermal Performance Enhancement of L-Shaped Microgrooved Heat Pipe Containing Water-Based Al2O3 Nanofluids

An experimental study was performed to investigate the thermal performance of an L-shaped grooved heat pipe with cylindrical cross section, which contained 0.5 wt% water-based Al₂O₃ nanofluid as the working fluid. The transient performance of the heat pipe and the effect of cooling water temperature on the heat transfer characteristics of the heat pipe were investigated. The outer diameter and the length of the heat pipe were 6 mm and 220 mm, respectively. Experimental results revealed that the temperature of the cooling water has a significant effect on the thermal resistance of the heat pipe containing nanofluids as its working fluid. By increasing the cooling water temperature from 5°C to 27.5°C, the thermal resistance decreases by approximately 40%. At the same charge volume, test results indicated an average reduction of 30% in thermal resistance of heat pipes with nanofluid as compared with heat pipe containing pure water. For transient conditions, unsteady state time for nanofluids was reduced by approximately 28%, when compared with water as the working fluid.     

Prediction of Poultry Egg Freshness Using Vis-Nir Spectroscopy with Maximum Likelihood Method

Crucial physio-chemical changes occuring in eggs during storage after laying lead to loss of egg freshness. In this research, a new method for prediction of egg freshness using transmission visible near infrared spectroscopy was investigated. For this purpose 300 eggs were stored at two control conditions: refrigerator (4–5°C, 75%RH) and room (24–25°C, 40%RH) then by special egg holder, transmission spectroscopy was measured. For two eggs groups, 25 eggs in each group, in six days were tested by spectroscopy, after that Haugh unit and air cell height was measured directly. The non-destructive visible near infrared spectroscopy spectral measurements from 300 to 1100 nm (832 length of wave) were done as well as Haugh unit, air cell height for each egg and created the database for both environments. Finally a maximum likelihood latent root regression algorithm was developed to predict Haugh unit and air cell height by spectrum observation. The database was randomly divided into two parts. Training data, was used for maximum likelihood latent root regression parameter tuning and training of the model and testing data, was used just for model evaluation. Results indicated that maximum likelihood latent root regression method showed good prediction ability with coefficient of determination (R²) value up to 0.82 and 0.86 for Haugh unit and air cell height, respectively for testing data set. The results showed this method was better in comparison with partial least square regression (R² up to 0.79 and 0.72 for air cell height and Haugh unit) which was already used for this prediction.     

Incentive regulation of electricity distribution networks: Lessons of experience from Britain

This paper reviews the recent experience of the UK electricity distribution sector under incentive regulation. The UK has a significant and transparent history in implementing incentive regulation in the period since 1990. We demonstrate the successes of this period in reducing costs, prices, and energy losses while maintaining quality of service. We also draw out the lessons for other countries in implementing distribution sector reform. We conclude by discussing the place of incentive regulation of networks within the wider reform context, the required legislative framework, the need for appropriate unbundling, the importance of quality of service incentives, the regulatory information requirements, and the role of sector rationalisation.     

The case for a new energy research,development and promotion policy for the UK

This paper is a critical assessment of the current balance of efforts towards energy research and development (R&D) and the promotion of low-carbon electricity technologies in the UK. We review the UK's main technological options and their estimated cost ranges in the medium term. We contrast the energy R&D spending with the current and expected future cost of renewable promotion policies and point out the high cost of carbon saving through existing renewable promotion arrangements. We also note that liberalisation of the electricity sector has had significant implications for the landscape of energy R&D in the UK. We argue that there is a need for reappraisal of the soundness and balance of the energy R&D and renewable capacity deployment efforts towards new energy technologies. We suggest that the cost-effectiveness of UK deployment policies needs to be more closely analysed as associated costs are non-trivial and expected to rise. We also make a case for considering increasing the current low level of energy R&D expenditure. Much of energy R&D is a public good and we should consider whether the current organisation of R&D effort is fit for purpose. We argue that it is important to build and maintain the research capability in the UK in order to absorb spillovers of technological progress elsewhere in the world. Against this background, the recent signs that an energy R&D renaissance could be underway are therefore positive and welcome.     

Machining stability in high-speed drilling—Part 1: Modeling vibration stability in bending

In this work, dynamic models for chatter in drilling are developed that deal with the transverse vibration due to bending, and the axial vibration due to torsion. In the first part, a dynamic model is developed to obtain the limit of stability for the bending vibration mode. The equations of motion are formulated based on a lumped representation of the drill, and the gyroscopic effect due to the rotation of the tool is included. It is shown that, including this gyroscopic effect has a profound effect on the resulting stability lobes, especially at very high speeds; it makes the lobes wider but at the same time lowers the minimum stability boundary. In the second part of this work, a time domain simulation model is developed that combines both bending and torsion modes. This model is verified [1] using experimental cutting tests.     

Comprehensive exergetic and economic comparison of PWR and hybrid fossil fuel-PWR power plants

A typical 1000 MW Pressurized Water Reactor (PWR) nuclear power plant and two similar hybrid 1000 MW PWR plants operate with natural gas and coal fired fossil fuel superheater-economizers (Hybrid PWR-Fossil fuel plants) are compared exergetically and economically. Comparison is performed based on energetic and economic features of three systems. In order to compare system at their optimum operating point, three workable base case systems including the conventional PWR, and gas and coal fired hybrid PWR-Fossil fuel power plants considered and optimized in exergetic and exergoeconomic optimization scenarios, separately. The thermodynamic modeling of three systems is performed based on energy and exergy analyses, while an economic model is developed according to the exergoeconomic analysis and Total Revenue Requirement (TRR) method. The objective functions based on exergetic and exergoeconomic analyses are developed. The exergetic and exergoeconomic optimizations are performed using the Genetic Algorithm (GA). Energetic and economic features of exergetic and exergoeconomic optimized conventional PWR and gas and coal fired Hybrid PWR-Fossil fuel power plants are compared and discussed comprehensively.     

Enhancement of Free Convection Heat Transfer from a Vertical Array of Isothermal Cylinders by Flow Diverters

Free convection heat transfer from a vertical array of five horizontal isothermal cylinders separated by flow diverters is investigated experimentally through a Mach-Zehnder interferometer. Flow diverters with widths of 1, 2, and 3 cylinder-diameter are placed midway between the cylinders with a 45-degree inclination angle. The cylinders vertical center to center spacing is kept constant to three-cylinder diameter. The experiments are carried out for various Rayleigh numbers based on the cylinder diameter in the range of 10³ to 2.5× 10³ and for different flow diverter width. It is observed that the flow diverters enhance the heat transfer of the array from 10% to 27%, depending on their width. By increasing the width of the diverters and the Rayleigh number, enhancement of the heat transfer from the array increases.