Concentrations and dietary exposure to polycyclic aromatic hydrocarbons (PAHs) from grilled and smoked foods

We investigated the concentrations and profiles of 16 priority polycyclic aromatic hydrocarbons (PAHs) in various grilled and smoked foods and estimated the dietary exposure of Kuwaiti children, adolescent and adult populations. Results indicated that non-carcinogenic PAHs were present at high proportions (60–100%) with phenanthrene showing the highest mean concentration (54.9 μg kg^?1, 37.1% of the total PAH concentrations). Among the genotoxic PAHs (PAH8), chrysene (4.88 μg kg^?1, 3.29%) and benz[a]anthracene (2.27 μg kg^?1, 1.53%) showed the highest mean values. Meat tikka contained the highest mean concentrations of benzo[a]pyrene (BaP) (2.48 μg kg^?1), total genotoxic PAHs (42.9 μg kg^?1), total PAHs (ΣPAHs) (648 μg kg^?1) and total benzo[a]pyrene equivalents (ΣBaPeq) (6.02 μg kg^?1). High levels of genotoxic PAHs were detected in grilled vegetables (21.1 μg kg^?1), shish tauk (20.5 μg kg^?1) and whole grilled chicken (20.3 μg kg^?1) samples. However, meat and chicken shawerma samples had low levels of PAH8. Meat tikka (437 ng/day, 641 ng/day), whole grilled chicken (160 ng/day, 241 ng/day), grilled vegetables (120 ng/day, 166 ng/day), meat burger (114 ng/day, 92.7 ng/day) were the major contributors to the daily intake of PAH8 in children/adolescent and adult populations, respectively. The total mean dietary intakes for children/adolescents and adults for BaP (8.09 ng/day, 9.20 ng/day), PAH8 (84.2 ng/day, 95.7 ng/day), ∑PAHs (974 ng/day, 1108 ng/day) and ∑BaPeq (14.8 ng/day, 16.8 ng/day) were comparable. Cancer risks for Kuwaiti children/adolescents and adults from dietary intake of ΣBaPeq from the animal-origin foods were determined to be 2.63/10⁷ and 9.3/10⁷, respectively.     

Short-term electric power load forecasting using feedforward neural networks

Abstract: This paper presents the results of a study on short‐term electric power load forecasting based on feedforward neural networks. The study investigates the design components that are critical in power load forecasting, which include the selection of the inputs and outputs from the data, the formation of the training and the testing sets, and the performance of the neural network models trained to forecast power load for the next hour and the next day. The experiments are used to identify the combination of the most significant parameters that can be used to form the inputs of the neural networks in order to reduce the prediction error. The prediction error is also reduced by predicting the difference between the power load of the next hour (day) and that of the present hour (day). This is a promising alternative to the commonly used approach of predicting the actual power load. The potential of the proposed method is revealed by its comparison with two existing approaches that utilize neural networks for electric power load forecasting.     

Properties of a fluorescent bezafibrate derivative (DNS-X). A new tool to study peroxisome proliferation and fatty acid β-oxidation

The first peroxisome proliferator-activated receptor (PPAR) was cloned in 1990 by Issemann and Green. Many studies have reported the importance of this receptor in the control of gene expression of enzymes involved in lipid metabolic pathways including mitochondrial and peroxisomal fatty acid β-oxidation, lipoprotein structure [apolipoprotein (apo) A2, apo Clll], and fatty acid synthase. By using radiolabeled molecules, it was shown that peroxisome proliferators bind and activate PPAR. As an alternative method, we developed a fluorescent dansyl (1-dimethyl-aminonaphthalene-5-sulfonyl) derivative peroxisome proliferator from bezafibrate (DNS-X), a hypolipidemic agent that exhibits an in vitro peroxisome proliferative activity on rat Fao-hepatic derived cultured cells. However, until now, the effect of this new compound on the liver of animals and subcellular localization was unknown. In addition to in vivo rat studies, we present a more efficient large-scale technique of DNS-X purification. Treating rats (DNS-X in the diet at 0.3% w/w) for 6 d leads to a hepatomegaly and a marked increase in liver peroxisomal palmitoyl-CoA oxidase activity. We also developed a method to localize and quantify DNS-X in tissues or cell compartment organelles. The primarily cytosolic distribution of DNS-X was confirmed by direct visualization using fluorescence microscopy of cultured Fao cells. Finally, transfection assay demonstrated that DNS-X enhanced the PPARα activity as well as other peroxisome proliferators do.     

CrN/AlN superlattice coatings synthesized by pulsed closed field unbalanced magnetron sputtering with different CrN layer thicknesses

CrN/AlN superlattice coatings with different CrN layer thicknesses were prepared using a pulsed closed field unbalanced magnetron sputtering system. A decrease in the bilayer period from 12.4 to 3.0 nm and simultaneously an increase in the Al/(Cr + Al) ratio from 19.1 to 68.7 at.% were obtained in the CrN/AlN coatings when the Cr target power was decreased from 1200 to 200 W. The bilayer period and the structure of the coatings were characterized by means of low angle and high angle X-ray diffraction and transmission electron microscopy. The mechanical and tribological properties of the coatings were studied using the nanoindentation and ball-on-disc wear tests. It was found that CrN/AlN superlattice coatings synthesized in the current study exhibited a single phase face-centered cubic structure with well defined interfaces between CrN and AlN nanolayers. Decreases in the residual stress and the lattice parameter were identified with a decrease in the CrN layer thickness. The hardness of the coatings increased with a decrease in the bilayer period and the CrN layer thickness, and reached the highest value of 42 GPa at a bilayer period of 4.1 nm (CrN layer thickness of 1.5 nm, AlN layer thickness of 2.5 nm) and an Al/(Cr + Al) ratio of 59.3 at.% in the coatings. A low coefficient of friction of 0.35 and correspondingly low wear rate of 7 × 10^− 7 mm³N^− 1m^− 1 were also identified in this optimized CrN/AlN coating when sliding against a WC-6%Co ball.     

Carcinogenic aspect of xenobiotic molecules belonging to the peroxisome proliferator family

STUDY DESIGN: Cervical motion patterns were analyzed in a normal population and in patients with cervical instability by using cineradiography. OBJECTIVES: To determine normal and pathologic motion patterns in the cervical spine through an in vivo continuous motion analysis. SUMMARY OF BACKGROUND DATA: Cineradiographic techniques have been used in a limited number of studies to quantify spinal motion. There is a paucity of information regarding dynamic motion patterns in normal and pathologic cervical spines. METHODS: Ten healthy subjects and 12 patients with unstable cervical spines (C1-C2 subluxation caused by rheumatoid arthritis, n = 10; instability below C2, n = 2) were studied. Cervical motion during flexion from the maximum extension position was recorded using cineradiography. Cervical segmental motions (C1-C2 to C5-C6) were continuously measured through quantifying cineradiographic images projected on a digitizer. RESULTS: Normal cervical spines showed a well-regulated stepwise motion pattern that initiated at C1-C2 and transmitted to the lower segments with time lags. Pathologic spines showed a different order of onset of segmental motion. In patients with rheumatoid arthritis who had atlantoaxial subluxation, C1-C2 motion initiated significantly earlier than C2-C3 motion. In patients with segmental instability below C2, motion in the unstable segments preceded that in the upper intact segments. CONCLUSIONS: Different motion patterns were observed between normal and pathologic cervical spines. Cineradiographic motion analysis is a valuable adjunctive technique, especially in diagnosis or evaluation of conditions that cannot be identified through conventional radiographic examination.     

Simulation of an Atmospheric Residue Desulfurization Unit by Quasi-Steady State Modeling

The current trend in petroleum refining is to maximize the conversion of the bottom of the barrel to improve the profitability of the refinery. Atmospheric residue desulfurization (ARDS) plays a key role in this, especially, when processing crudes with moderate to high sulfur contents. A deterministic quasi-steady state model has been developed to simulate the long term behavior of the reaction section of an atmospheric residue desulfurization (ARDS) unit, consisting of four co-current catalytic trickle bed reactors in series. The model uses the properties of the feedstock and the catalyst and is capable of simulating profiles of sulfur, coke, and metal depositions and the temperature along the reactors, taking into account also catalyst deactivation. Hydrogen quenching has also been simulated and simulation results predict all the essentials of the long term behavior of both experimental and industrial scale ARDS reactors satisfactorily. Comparing the simulation results with actual commercial data, the model predicted perfectly the middle part of the run. The model is unable to simulate the End-of-Run conditions due to pore mouth plugging phenomenon.     

Electrochemical aspects of exfoliation corrosion of aluminium alloys: The effects of heat treatment

Electrochemical approaches are used to investigate the exfoliation corrosion (EFC) of a 7XXX series aluminium alloy that has undergone different tempering treatments. EFC was produced under an artificial crevice at open circuit potential in neutral chloride solutions, and is found to be associated to current and potential transients. EFC was also produced under galvanostatic control conditions. Observations made through Scanning Electron Microscopy (SEM) suggest that these transients result from the progression of inter-granular cracks. Last, over-ageing heat treatments that are known to decrease both metal hardness and EFC sensitivity were found to decrease the number of transients.     

Hardware Implementation for a Genetic Algorithm

A genetic algorithm (GA) can find an optimal solution in many complex problems. GAs have been widely used in many applications. A flexible-very-large-scale integration intellectual property for the GA has been proposed in this paper. This algorithm can dynamically perform various population sizes, fitness lengths, individual lengths, fitness functions, crossover operations, and mutation-rate settings to meet the real-time requirements of various GA applications. It can be seen from the simulation results that our design works very well for the three examples running at an 83-MHz clock frequency.     

Ionic Conductivity in Glasses and Melts (Up to 1950K): Application to the CaO–SiO<Subscript>2</Subscript> System

T he electrical properties of the CaO–SiO₂ system have been investigated in a wide temperature range (up to 1950 K) using a specific device developed in this laboratory. Conductivity data were obtained in the liquid, undercooled-liquid, and glassy states for two different compositions. In the solid state, the conductivity is determined by the jump of the Ca²⁺ cations along the non-bridging oxygens. This mechanism is thermally activated with a high activation energy value. A second regime was observed in the molten state where the conductivity follows the phenomenological Vogel–Tammann–Fulcher (VTF) law. In this regime, the conductivity is enhanced because the softening and the deformation of the network facilitate the migration of the alkaline-earth cations.