Ultrasonication as pretreatment for drying of tomato slices in a hot air–microwave hybrid oven

This study aims to investigate the effect of ultrasonic pretreatment on drying time and quality properties of tomato slices dried by microwave combined with hot air at 60°C. The influence of ultrasound pretreatment (0, 20, and 40?min) and microwave power (120, 150, and 180?W) on drying time, color, total phenolic content, lycopene, vitamin C, and rehydration capacity of dried slices of tomato was studied. Results showed that as the microwave power level increased, drying time decreased significantly (about 46.4%). Ultrasound pretreatment decreased the drying time by 7.38% only at 120?W microwave power and 40?min of pretreatment compared to those without ultrasound pretreatment at the same microwave power. Depending on drying conditions, vitamin C and lycopene contents reduced from 433.94 to 81.89?mg AA/100?g dry solids and 3920.57 to 415.40?mg/100?g dry solids, respectively. The change in total phenolic content was not severe as much as vitamin C contents. Rehydration capacity of pretreated samples was larger than nontreated samples. The color values of dried tomato slices were in the acceptable range. Both microwave power and ultrasound pretreatment affected the quality of the final product significantly.     

The influence of thermal pretreatment of Re/γ-alumina catalysts in hydrogen on their activity for hydrogenation and hydrogenolysis of benzene

The specific activity of Re/-alumina catalysts (10.4 and 1.04 wt% Re) preheated in hydrogen at 550–800°C for benzene hydrogenation and hydrogenolysis at 80–300°C has been found to not change or to increase with increasing pretreatment temperature, respectively. The results are discussed in relation to the metal dispersion.     

An improvement on Martin–Hou equation of state for more precise prediction in the liquid region

A modified Martin–Hou (M–H) equation of state (EOS) for the accurate representation of thermodynamic property data of some pure substances in liquid phase is presented in this work. The improvement is achieved by substituting a new parameter η into the original M–H EOS. Eighteen pure substances are chosen to construct the dependency relationship of η on reduced temperature T_r and acentric factor ω. Furthermore, to verify the effectiveness and improvement of the modified M–H EOS, the calculated values of the saturated vapor and liquid molar volumes are compared with the literature data in the reduced temperature ranging from approximately 0.6 to 1.0. The results show that the modified M–H EOS perform a good prediction in gaseous phase for pure substances with the average absolute deviation (AAD) generally less than 1%, and more precise liquid molar volume values can be obtained with the modified equation. In liquid phase, the AAD of the modified M–H EOS is 3.71%, which is much lower than 6.16% of the original M–H EOS.     

Study on CO2 reforming of methane to syngas over Al2O3–ZrO2 supported Ni catalysts prepared via a direct sol–gel process

Ni-based catalysts supported on Al₂O₃–ZrO₂ (Ni/Al₂O₃–ZrO₂) were prepared by a direct sol–gel process with citric acid as the gelling agent. The evaluation of the catalyst prepared for methane reforming with CO₂ was carried out with thermal gravimetric analysis (TGA), infrared spectroscopy (IR), X-ray diffraction (XRD), microscopy analyses (SEM and TEM), temperature-programmed reduction (TPR) and in a micro-reactor system. The catalytic performance for CO₂ reforming of methane to synthesis gas in a continuous-flow micro-reactor under atmospheric pressure was investigated. TGA, IR, XRD and microscopy analyses show that the Ni particles have a nanostructure of around $5\mathrm{nm}$ and are uniformly dispersed on the Al₂O₃–ZrO₂ support, which exists as an amorphous phase. Catalytic tests using CO₂ reforming of methane to synthesis gas show that the catalytic activity increases with increasing metal loading, and the 20Ni/Al₂O₃–ZrO₂ (0.2 Ni/Al molar ratio) catalyst has excellent activity and stability, compared with that of the Al₂O₃ supported Ni catalyst, with 91.9% conversion of CO₂ and 82.9% conversion of CH₄ over $50\mathrm{h}$ at $1073\mathrm{K}$, atmospheric pressure, hourly space velocity of $11,200\mathrm{ml}{\mathrm{gcat}}^{-1}{\mathrm{h}}^{-1}$ and CH₄:CO₂:N₂ of 2:2:1. The excellent catalytic activity and stability is attributed to the very highly and uniformly dispersed small metallic Ni particles, the reducibility of the Ni oxides and an interaction between metallic Ni particles and the support Al₂O₃–ZrO₂.     

Pd–Pt bimetallic catalyst supported on SAPO‐5 for catalytic combustion of diluted methane in the presence of water vapor

The examination of the combustion of a trace amount of methane over Pd‐ion‐exchanged silicoaluminophosphate‐5 (Pd‐SAPO‐5) at low temperature in the presence of water vapor reveals that water vapor strongly depresses methane combustion and causes a significant decrease in catalytic activity with time. The newly prepared bimetallic catalyst Pd–Pt‐SAPO‐5, on the other hand, shows higher performance for methane combustion under similar conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Promotional effect of Ca on the Pd/Ce–Zr/Al2O3 catalyst for low-temperature catalytic combustion of methane

Promotional effect of Ca on the catalytic property of Pd/Ce–Zr/Al₂O₃ catalyst towards methane combustion is examined. The surface properties and the oxidation/reduction behavior of these catalysts are investigated by BET, TEM, XPS, TPR, TPO and TPSR techniques. Activity tests in methane combustion show that addition of Ca to Pd/Ce–Zr/Al₂O₃ can promote remarkably its low-temperature activity. The thermal stability of the Pd/Ce–Zr/Al₂O₃ catalyst to the exposure at high temperature is also enhanced by Ca loading. XPS and TEM results show that the addition of Ca to Pd/Ce–Zr/Al₂O₃ catalyst generates well-dispersed PdO particles on support. H₂–TPR, O₂–TPO and CH₄/O₂–TPSR experiments show that the addition of Ca improves the reduction/reoxidation properties and thermal stability of the active PdO species, which increases the catalytic activity and thermal stability of the Pd/Ce–Zr/Al₂O₃ catalyst.     

Nitrogen and sulphur fertilization effect on leaching losses, nutrient balance and plant quality in a wheat–rapeseed rotation under a humid Mediterranean climate

An unbalanced S and/or N fertilization may have low N and S use efficiency together with substantial negative implications for yield, nutrient losses and plant quality parameters. The effect of N and S fertilization and their interactions on N?CS balances, on N?CS losses and on some plant quality parameters were investigated in a field experiment with a wheat (Triticum aestivum L.)?Crapeseed (Brassica napus L.)?Cwheat rotation (2005?C2008). The study was conducted under humid Mediterranean climatic conditions on a potentially S deficient soil. The effects of N (0, 140, 180, 220?kg?N?ha^?1 in wheat; 0, 100, 140, 180, 220?N?ha^?1 in rapeseed) combined with S fertilizer rates (0, 16 and 32?kg S ha^?1 in wheat and 0, 30, 60?kg S ha^?1 in rapeseed) were studied. Nitrogen fertilization increased yield by 55?% in wheat and 60?% in rapeseed, N concentration in grain and straw and S concentration in the grain of wheat. However, it led to a reduction in the S concentration of straw and the oil content of the rapeseed seed. The S application did not increase yield but had a positive effect on S concentration in the wheat straw. Glucosinolate concentration, a potentially toxic secondary metabolite in rapeseed, was not influenced by N or S applications. Nitrate leaching tended to increase with N application while sulphate leaching decreased. A net N and S mineralization was observed in each growing season, except for the first year in which a net S immobilization was observed. To make N fertilizer recommendations, the N mineralization from the previous crop residues should be taken into account. For S fertilizer recommendations, N supply is the most important item both from a qualitative point of view (N/S ratio in wheat grain) and an environmental point of view (S leaching).     

The effect of beta-alanine supplementation on neuromuscular fatigue in elderly (55–92 Years): a double-blind randomized study

Background

Ageing is associated with a significant reduction in skeletal muscle carnosine which has been linked with a reduction in the buffering capacity of muscle and in theory, may increase the rate of fatigue during exercise. Supplementing beta-alanine has been shown to significantly increase skeletal muscle carnosine. The purpose of this study, therefore, was to examine the effects of ninety days of beta-alanine supplementation on the physical working capacity at the fatigue threshold (PWC_FT) in elderly men and women.

Methods

Using a double-blind placebo controlled design, twenty-six men (n = 9) and women (n = 17) (age ± SD = 72.8 ± 11.1 yrs) were randomly assigned to either beta-alanine (BA: 800 mg × 3 per day; n = 12; CarnoSyn?) or Placebo (PL; n = 14) group. Before (pre) and after (post) the supplementation period, participants performed a discontinuous cycle ergometry test to determine the PWC_FT.

Results

Significant increases in PWC_FT (28.6%) from pre- to post-supplementation were found for the BA treatment group (p < 0.05), but no change was observed with PL treatment. These findings suggest that ninety days of BA supplementation may increase physical working capacity by delaying the onset of neuromuscular fatigue in elderly men and women.

Conclusion

We suggest that BA supplementation, by improving intracellular pH control, improves muscle endurance in the elderly. This, we believe, could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women.     

Elasticity or viscosity,which one is more influential on the internal structure of a core-shell morphology in ternary blends?

The goal of this research was to study the internal phase structure of core-shell morphology within a ternary blend and look into the affecting parameters. In this way, a series of SEBS/SAN/PA6 ternary blends representing core-shell morphology were prepared and effect of viscosity and elasticity of core-forming component on the phase structure of core droplets were investigated. Studies based on the scanning electron microscopy micrographs demonstrated that elasticity plays a more dominant role on the formation of single or multi-core droplets. In addition, it was inferred that absolute elasticity of core component is more influential rather than elasticity ratio of core and shell components. Furthermore, morphology of prepared samples compared with predictions of DIE and modified DIE conceptual models.     

The effect of phase formation during use on the chemical corrosion of magnesia–chromite refractories in contact with a non-ferrous PbO–SiO2 based slag

One of the main factors limiting the lining lifetime in pyrometallurgical smelters is continuous refractory oxides dissolution in the slag bath. The overall wear is accelerated when the slag infiltrates the porous brick and the dissolution thus occurs in a larger part of the lining. This work investigates the possibility of preventing deep infiltration by sealing off the pores with newly formed phases. Static finger tests at constant temperature (1200 °C) were performed in contact with a synthetic non-ferrous PbO–SiO₂–MgO slag, showing the formation of forsterite (Mg₂SiO₄) throughout the refractory sample by the reaction between SiO₂ (slag) and MgO (refractory). This phase grows with time, eventually sealing off the pores near the interface with the bath. The phase grows too slow to prevent full infiltration of the refractory but creates an equilibrium state in the sealed off part of the sample, ceasing the chemical corrosion in that part of the sample.     

EVOO’s Effects on Incretin Production: Is There a Rationale for a Combination in T2DM Therapy?

Type 2 diabetes mellitus (T2DM) is a serious public health concern as it is one of the most common chronic diseases worldwide due to social and economic developments that have led to unhealthy lifestyles, with a considerable impact both in terms of morbidity and mortality. The management of T2DM, before starting specific therapies, includes cornerstones such as healthy eating, regular exercise and weight loss. Strict adherence to the Mediterranean diet (MedDiet) has been related to an inverse association with the risk of T2DM onset, as well as an improvement in glycaemic control; in particular, thanks to the consumption of extra virgin olive oil (EVOO). Agonists of gut-derived glucagon-like peptide-1 (GLP-1), gastrointestinal hormones able to increase insulin secretion in response to hyperglycaemia (incretins), have been recently introduced in T2DM therapy, quickly entering the international guidelines. Recent studies have linked the action of EVOO in reducing postprandial glycaemia to the increase in GLP-1 and the reduction of its inactivating protease, dipeptidyl peptidase-4 (DPP-4). In this review, we explore observations regarding the pathophysiological basis of the existence of an enhanced effect between the action of EVOO and incretins and, consequently, try to understand whether there is a rationale for their use in combination for T2DM therapy.     

A Reynolds mass flux model for gas separation process simulation:II. Application to adsorption on activated carbon in a packed column☆

Simulations of adsorption process using the Reynolds mass flux model described in Part I of these serial articles are presented. The object of the simulation is the methylene chloride adsorption in a packed column (0.041 m id, packed with spherical activated carbon up to a length of 0.2 m). With the Reynolds mass flux model, breakthrough/regeneration curves, concentration and temperature as well as the velocity distributions can be obtained. The simulated results are compared with the experimental data reported in the literature and satisfactory agreement is found both in breakthrough/regeneration curves and temperature curves. Moreover, the anisotropic turbulent mass diffusion is characterized and discussed.     

How good is the evidence for a favourable effect of very long chain n‐3 polyunsaturated fatty acids on cardiovascular disease?

The evidence for beneficial effects of very long chain (VLC) n‐3 polyunsaturated fatty acids (PUFA) on cardiovascular disease (CVD) is strong because it is based on the results of adequately powered intervention trials with disease endpoints. This contrasts with the evidence for a detrimental effect of saturated fat on CVD which is weak because such studies have not been carried out. Accordingly, any set of dietary recommendations which attaches more importance to saturated fat intakes than VLC n‐3 PUFA intakes can be questioned. Despite the strength of the evidence there are practical difficulties associated with implementing the recommendation to increase intake of VLC n‐3 PUFA to 1g per day which need to be overcome. These include the acceptability of fatty fish consumption, the presence of methyl mercury in fish at the top of the food chain and declining global fish stocks.     

The effect of magnetic field on the impurity binding energy of shallow donor impurities in a Ga1?xInxNyAs1?y/GaAs quantum well

Using a variational approach, we have investigated the effects of the magnetic field, the impurity position, and the nitrogen and indium concentrations on impurity binding energy in a Ga_1−xIn_xN_yAs_1−y/GaAs quantum well. Our calculations have revealed the dependence of impurity binding on the applied magnetic field, the impurity position, and the nitrogen and indium concentrations.     

Liquid-phase oxidation of normal C<Subscript>10</Subscript>–C<Subscript>13</Subscript> hydrocarbons with hydrogen peroxide on the titanium-containing catalyst ts-1: The effect of process conditions on product composition

Severe economic challenges and stringent environmental regulations have made it necessary to devise new higher fatty alcohol synthesis technologies in order to replace the existing processes, which produce large amounts of waste, or to eliminate or considerably lessen their drawbacks. Processes using hydrogen peroxide, an environmentally friendly oxidizer, are of great interest in this respect. Here we report the effect of process conditions (the initial molar ratio of reactants and temperature) on the proportions of the products (alcohols and ketones) of the liquid-phase oxidation of normal C₁₀–C₁₃ hydrocarbons on a heterogeneous titanium-containing silicalite catalyst (TS-1). The main products of the reaction are alcohols and ketones, and the proportion of the alcohols in the reaction mixture decreases as the temperature is raised and as the hydrocarbon-to-hydrogen peroxide molar ratio is decreased.     

A simple oxidation–reduction process for the activation of a stainless steel surface to synthesize multi-walled carbon nanotubes and its application to phenol degradation in water

Aligned multi-walled carbon nanotubes (MWCNTs) were synthesized directly on a stainless steel surface by surface activation by intense oxidation in air followed by a moderate reduction in H₂ without any wet process. This method is extremely simple compared with conventional ways that need catalyst loading steps or acid pre-etching steps to synthesize carbon nanotubes on stainless steel surfaces. It was found that the length of MWCNT bundles could reach 80 μm when the oxidation step was properly controlled. It was demonstrated that MWCNTs synthesized on stainless steel meshes could be used as a catalyst support to enhance ozone oxidation in the decomposition of phenol in water.     

An optimization method for enhancement of gas–liquid mass transfer in a bubble column reactor based on the entropy generation extremum principle

In this study, an optimization method is proposed to enhance the gas–liquid mass transfer in bubble column reactor based on the entropy generation extremum principle. The mass transfer–induced entropy generation can be maximized with the increase of mass transfer rate, based on which the velocity field can be optimized. The oxygen gas–liquid mass transfer is the major rate–limiting step of the toluene emissions biodegradation process in bubble column reactor, so the entropy generation due to oxy...     

Effect of hydrogen on methane conversion to hydrocarbons in “one‐step” reaction under non‐oxidative conditions at low temperature over Pd–Co/SiO2 catalysts prepared by the sol/gel method

Methane conversion to higher hydrocarbons in a “one‐step” process under non‐oxidative conditions at low temperature was here first introduced and investigated over Co–Pd/SiO₂ catalysts at 250°C as a function of hydrogen concentration in helium and of catalyst composition. A maximum in the production of C₂₊ hydrocarbons including aromatics (benzene and toluene) was observed at 1.3 vol% H₂/He mixture in which one pulse of methane was introduced. Additional hydrogenation with the same H₂/He mixture at 400°C was efficient to remove the larger hydrocarbon fragments already existing on the surface. On pure Pd/SiO₂ the one‐step process is not so efficient as on cobalt‐rich samples, but in the latter case the hydrocarbon removal is the most efficient during high‐temperature hydrogenation. It was found that methane conversion in the one‐step process is at least 2.5 times greater than that measured in the “two‐step” process and, in some cases, 80% of the methane introduced is converted to larger hydrocarbons. The results are discussed in terms of the hydrogen coverage ensuring the optimum hydrogen content in the surface CH_x species leading to chain growth. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analysis of the kinetics for the H2 + - \frac{1}{2}O2 ⇌ H2O reaction on a hot Pt surface in the pressure range 0.10–10 Torr

The H₂ + O₂ ⇌ H₂O reaction on platinum at 700 and 1300 K has been studied. A stagnation flow geometry was used with a gas mixture of H₂ and O₂ at pressures between 0.10 and 10 Torr. Comparing SHG results with simulations using different reaction parameters, it was concluded that , and . LIF measurements showed an ambiguity in the choice of main water-producing channel. Both hydrogen addition with low sticking coefficients and hydroxyl disproportionation with high sticking coefficients are plausible. This revised version was published online in July 2006 with corrections to the Cover Date.