Content of trans,trans‐2,4‐decadienal in deep‐fried and pan‐fried potatoes

Trans,trans‐2,4‐decadienal is a by‐product of frying oil that is also transferred to fried food. This aldehyde has been found and quantified both in frying oils and fumes generated during frying. Furthermore, it has been reported that 2,4‐decadienal has cytotoxic and genotoxic effects and promotes LDL oxidation. In the present work trans,trans‐2,4‐decadienal was detected directly in fried potatoes (french‐fries). Moreover, the influence of frying conditions (deep‐frying, pan‐frying), the oil type (olive oil, sunflower oil, cottonseed oil, palm oil and a vegetable shortening) and the degree of thermal deterioration (eight successive frying sessions without replenishment) on the production of 2,4‐decadienal in oil and potatoes was studied. The isolation of the aldehyde was performed by methanol extraction, while the identification and quantification was performed by RP‐HPLC. The quantity of trans,trans‐2,4‐decadienal produced during successive pan‐frying demonstrated a peak at the third and fourth frying session. The highest concentration of trans,trans‐2,4‐decadienal was detected in potatoes fried in sunflower oil, and the lowest in olive oil. The quantity of trans,trans‐2,4‐decadienal in fried potatoes decreased during successive deep‐frying at the seventh frying session or remained stable, except for cottonseed oil. The quantity of trans,trans‐2,4‐decadienal in fried potatoes was considered to be dependent on the oil used, on the frying process and, to a lesser extent, on the oil deterioration. In all cases tested, the highest concentration of trans,trans‐2,4‐decadienal was detected during deep‐frying. The unsaturation degree of the frying oil was considered to promote the formation of trans,trans‐2,4‐decadienal. Considering the quantity of 2,4‐decadienal found in french‐fries and in the respective frying medium, direct quantification of 2,4‐decadienal is required in order to make an estimation of intake from french‐fries.     

α‐Alumina nanospheres from nano‐dispersed boehmite synthesized by a wet chemical route

In this work, stable aqueous suspensions of nano‐boehmite were developed through a hybrid wet‐chemical route that uses hyperbranched dendritic poly(ethylene)imine (PEI) as template material for boehmite formation aiming at the development of a deagglomerated α‐alumina nanopowder after calcination. The method involves firstly the interaction between the Al precursor and PEI followed by the hydrolysis and polycondensation reactions. The study was aiming to investigate the effect of solids content and pH during reactions on both the stability of the final suspension and the morphology of the resulting nanocrystals. For this purpose, the suspensions were evaluated through viscosity measurements, zeta potential analyses, FT‐IR, DLS and sedimentation studies, whereas after the proper centrifugation, drying, and calcination steps, the as‐received nanocrystals were evaluated through SEM, TEM and XRD studies. In addition, the boehmite nanopowder was studied using Thermogravimetric and Differential Thermal Analysis, whereas its sinterability was evaluated by dilatometric measurements. The investigation showed that the conditions employed affect greatly both the morphology of nanocrystals as well as the dispersion and the stability of the suspensions. The boehmite suspension with the optimum dispersion and stability can lead, after calcination at 1050°C, to a fine deagglomerated α‐alumina nanopowder with a mean size at about 10 nm.     

Influence of salinity on lead and cadmium accumulation by the salt cedar (Tamarix smyrnensis Bunge)

BACKGROUND: The removal of heavy metals from polluted soils through the use of suitable plants has attracted much interest over recent decades. In this study Tamarix smyrnensis Bunge has been investigated for the characterization of its metal tolerance and ability to accumulate Pb and Cd, in order to evaluate its effectiveness as a cleanup tool for phytoextraction applications. For this purpose, two hydroponic experiments were performed, one with lead at concentration 100 ppm and a second with cadmium at concentration 5 ppm and at three different salt concentrations (0, 100, 200 mmol L^?1 NaCl). RESULTS: The experimental results showed that Pb and Cd accumulation in shoots ranged from 150–270 ppm and 7.5–42 ppm, respectively, and salinity was found to increase metal accumulation in shoots. However, the presence of high metal and salt concentrations affected negatively the health and finally the survival of the plants. CONCLUSION: T. smyrnensis is neither a Pb nor a Cd hyperaccumulator; however, metal accumulation levels in shoots considered together with its high biomass production suggest that it could be used for phytoextraction applications. Furthermore, salinity has a positive influence on Pb and Cd accumulation in harvestable parts of the plant when it remains in low concentrations. Copyright © 2009 Society of Chemical Industry     

环氧丙烷-环氧乙烷-环氧丙烷嵌段共聚醚P_x E_(39) P_x系列的合成与结构表征

本文用常压合成方法制备了中央嵌段为39个环氧乙烷单位的环氧丙烷-环氧乙烷-环氧丙垸三嵌段共聚醚P_xE_(3(?))P_x系列;用凝胶渗透色谱法(HPGPC)与质子核磁共振法(′HNMR)表征系列的嵌段组成;用小角X射线衍射(SAXD)、低频拉曼光谱、差示扫描量热法(DSC)研究了系列的固态结构形态。研究表明:固态的P_xE_(3(?))P_x共聚醚系列由单层晶片堆集而成,非折迭的分子鏈在片中的取向一般是傾斜于片的端面。     

Steady Homann flow and heat transfer of an electrically conducting second grade fluid

The steady axisymmetric flow and heat transfer of an incompressible, electrically conducting non-Newtonian second grade fluid impinging on a flat plate is investigated. An external uniform, transverse magnetic field is applied at the surface of the plate. Similarity transformation is used to reduce the resulting highly nonlinear partial differential equations into ordinary differential equations. An effective numerical scheme has been adopted to solve the nonlinear ordinary differential equations. The effects of non-Newtonian flow parameters and the magnetic field on the momentum and thermal boundary layers are discussed in detail and shown graphically. It is interesting to find that the non-Newtonian parameter and the magnetic parameter have opposite effects on the momentum and thermal boundary layers. The skin friction coefficient decreases exponentially with an increase in the non-Newtonian viscoelastic parameter and increases linearly with an increase in the magnetic parameter.     

New bit loading algorithms for DMT systems based on the greedy approach

The performance of a DMT system, which transmits information over channels with varying characteristics through the frequency zones, is improved when the subchannels of the system are loaded with variable data rate. In this study, we meet the bit loading problem of the subcarriers of a DMT system. We propose two new optimum‐loading algorithms with low computational complexity. These algorithms assign integer number of bits successively until a target bit rate is fulfilled. We compare them with several existing algorithms in terms of transmitting energy versus data rate and complexity versus system's characteristics i.e. number of subcarriers and target data rate. Simulations prove that without sacrificing optimality both our proposals present a lower complexity level. Copyright © 2006 John Wiley & Sons, Ltd.     

Automated pressure ulcer lesion diagnosis for telemedicine systems.

In this work we examine the potential of using digital images to classify regions appearing in pressure ulcer images and thus being able to have a diagnosis about the patient's current state. We capitalize on telemedicine infrastructure, which can overcome difficulties posed by remote patient location, and we aim to provide diagnostic tools that will satisfy the above requirements.     

The Influence of Plasma-Based Nitriding and Oxidizing Treatments on the Mechanical and Corrosion Properties of CoCrMo Biomedical Alloy

Metallurgical and Materials Transactions A - Plasma-based nitriding and/or oxidizing treatments were applied to CoCrMo alloy to improve its surface mechanical properties and corrosion resistance...