Synthesis of MIL-101@g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> nanocomposite for enhanced adsorption capacity towards CO<Subscript>2</Subscript>

MIL-101@g-C₃N₄ nanocomposite was prepared by solvothermal synthesis and used for CO₂ adsorption. The parent materials (MIL-101 and g-C₃N₄) and the MIL-101@g-C₃N₄ were characterized by X-ray diffraction, argon adsorption/desorption, Fourier transform infrared spectroscopy, thermal analysis (TG/DTA), transmission electronic microscopy, and Energy-dispersive X-ray spectroscopy. The results confirmed the formation of well-defined MIL-101@g-C₃N₄ with interesting surface area and pore volume. Furthermore, both MIL-101 and MIL-101@g-C₃N₄ were accomplished in carbon dioxide capture at different temperatures (280, 288, 273 and 298 K) at lower pressure. The adsorption isotherms show that the nanocomposite has a good CO₂ adsorption affinity compared to MIL-101. The best adsorption capacity is about 1.6 mmol g^?1 obtained for the nanocomposite material which is two times higher than that of MIL-101, indicating strong interactions between CO₂ and MIL-101@g-C₃N₄. This difference in efficacy is mainly due to the presence of the amine groups dispersed in the nanocomposite. Finally, we have developed a simple route for the preparation of an effective and new adsorbent for the removal of CO₂, which can be used as an excellent candidate for gas storage, catalysis, and adsorption.     

Numerical study of natural convection in a cavity of high aspect ratio by using the lattice Boltzmann method

A comprehensive numerical study has been conducted to investigate two‐dimensional, steady heat transfer of natural convection in a divided enclosure of high aspect ratio. The vertical walls of the enclosure are maintained at different temperatures, while the horizontal walls are adiabatics. A numerical hybrid scheme with lattice Boltzmann for fluid velocity and finite difference for the temperature is adopted. Parametric studies of the effects of aspect ratio, number and length of partitions attached to the cold wall of the enclosure on heat transfer and fluid flow have been performed. Copyright © 2007 John Wiley & Sons, Ltd.     

An Accurate Combination of on-the-fly Interface Trap and Threshold Voltage Methods for NBTI Degradation Extraction

The Negative bias temperature instability (NBTI) is one of the most important reliability issues for modern CMOS technology. Accurate reliability prediction necessitates physically based models for NBTI and accurate methods for estimation of interface (?N _it ) and oxide trap (?N _ot ) generated under this degradation as well as mobility degradation (?μ _eff /μ _eff0 ). In this paper, we propose an accurate approach to estimate ?N _it , ?N _ot and ?μ _eff /μ _eff0 induced by NBTI degradation. This approach is based on combining on-the-fly interface trap (OTFIT) and on-the-fly threshold voltage (OTF-V_th) methods in the same time measurement setup, contrary to the classical combination where the two methods (OTFIT and OTF-V_th) are applied separately in two different measurements setups and using two transistors. In addition, the contribution of border trap to the charge pumping (CP) current in OTFIT is minimized using the high frequency signal and the scan band energy of the two combined methods is calibrated. Therefore, the data set of OTFIT and OTF-V_th can be directly comparable. The proposed approach can contribute to further understand the behavior of the NBTI degradation, especially through the mobility degradation and the threshold voltage shift contributions of interface (?V _it ) and oxide traps (?V _ot ).     

Robust $$\mathcal{H}_\infty$$ H ∞ Observer-based Stabilization of Linear Discrete-time Systems with Parameter Uncertainties

International Journal of Control, Automation and Systems - This paper addresses the problem of observer-based stabilization of discrete-time linear systems in presence of parameter uncertainties...     

Δ6 and Δ5 desaturase activities in liver from obese zucker rats at different ages

Δ6 Desaturation of linoleic acid (18∶2 n−6) and Δ5 desaturation of dihomo-γ-linolenic acid (20∶3 n−6) were measured in liver microsomes from genetically obese Zucker rats (fa/fa) and from their lean littermates (Fa/−). Both groups were fed a balanced commercial diet. The rats were 6, 9 and 12 weeks old, which corresponded to stages in their active growth period. The content of total fatty acids and n−6 polyunsaturated fatty acids in whole liver and liver microsomes was also determined in order to ascertain how the desaturase activities measuredin vitro reflected regulation of essential fatty acid metabolismin vivo. Contrary to values obtained for Δ6 desaturation, Δ5 desaturation at nonsaturating substrate levels were lower in obese rats than in lean controls. In contrast, at saturating substrate level, the maximal Δ5 desaturase activities were the same in both phenotypes and they increased with age. Study of Δ5 desaturation kinetics (1/V vs 1/S) showed that V_m did not differ between 12-week-old obese and lean rats, whereas K_M in obese rats was much lower than in controls, expressing the very low affinity of the enzyme for the substrate in obese animals. The fatty acid composition of liver lipids reflected the results of desaturase activitiesin vitro. In particular, the ratios 20∶4 n−6/20∶3 n−6 were lower in obese rats than in lean rats, which can be explained by the lower conversion of 20∶3 n−6 into 20∶4 n−6 by Δ5 desaturation. However, the total amount of 20∶4 n−6 in the whole liver did not differ between phenotypes, whatever their age. This work presents evidence for a relationship between the changes in fatty acid compositional data in hepatic total lipids, total lipids of liver microsomes and modifications of fatty acid desaturase activities in the genetically obese Zucker rat.     

Demand for Scientific Articles and Citations: An Example from the Institut de l'information scientifique et technique (France)

The patterns that appear in exchanges between researchers, scientific journal publications and the demand for scientific articles often intersect, but the logic behind each type of activity is not necessarily the same. Analyses of requests for scientific articles from document suppliers may help to interpret current developments in electronic publishing.This study of article requests to the Institut de l'information scientifique et technique (INIST) shows that, in France, document supply customers fall into three main categories: business, academic libraries and public research organisations, in descending order. Demand focuses mainly on medicine, pharmacology, biology and chemistry, and the distribution of articles is entirely in accordance with the laws of bibliometrics.A further comparative analysis shows a high reciprocal correlation (except in the physical sciences) between the 50 journals most frequently requested from INIST, and the 50 most frequently cited journals according to ISI (Institute for Scientific Information). The titles which did not appear in either one list or the other show that the most frequently cited physics journals are not necessarily requested from the document supplier, and that, conversely, some frequently requested journals are not often cited. It may therefore be assumed that a trade in electronic articles is likely to develop quite rapidly in disciplines which are common to both lists, although this would focus on reputed titles only, but that a different pattern of electronic document exchange would emerge for scientific literature in other disciplines.     

Study of the Static Properties I-V of Mosfet

Today, telecommunications, data processing, physics and electronics, take a very important place in the activities of research of the various laboratories. In the field of the ultra high frequencies, the field-effect transistor MOSFET caused many studies and research to exploit its interesting and promising characteristics as well as possible. The objective of this contribution is devoted to study the static properties I-V of MOSFET. The study enables us to calculate the drain current as function of bias in both linear and saturated modes; this effect is evaluated using a numerical simulation program, one could notice that the MOS transistor characteristics are very sensitive to the temperature. The load of inversion via the threshold voltage and the mobility of the carriers are the two principal impacted parameters, it was noted that the increase in the temperature induces a drop of the threshold voltage like that of mobility, and an immediate consequence of this reduction is the diminution in the drain current. One can thus conclude that the temperature influences the performances of the device; more it is low, better is the reliability of the device under operation.