Analytical models of subthreshold swing and threshold voltage forthin- and ultra-thin-film SOI MOSFETs

Analytical models are proposed for thin- and ultra-thin film silicon-on-insulator (SOI) MOSFETs operating in weak or strong inversion. The models take into account all the device parameters. The cases of two and three interfaces with a silicon substrate are considered in the modeling and compared with one another. These models give the main electrical MOSFET parameters in ohmic operation (subthreshold swing and threshold voltage) for these structures. The basic approximation is the consideration of a linearly varying potential in the Si film, which has been inferred on the basis of numerical simulations. Various behaviors depending on the Si film and the buried insulator thickness as well as the interface charges, Si film doping, or substrate regime are simulated to assess the properties and the performances of SOI MOS transistors and to validate the analytical models     

Effect of the addition of nitrate to milk on the formation of volatile N-nitrosamines and apparent total N-nitroso compounds

 Saint-Paulin, a French semihard cheese, was manufactured from milk with and without added NO₃ ^–. Reference and experimental cheeses were analysed at different stages of ripening for the presence of apparent total N-nitroso compounds (ATNC) by chemical denitrosation and chemiluminescence detection (thermal energy analyser). The fate of NO₃ ^– and NO₂ ^–was also scrutinized. The levels of ATNC and of volatile N-nitrosamines were followed during ripening. After 60 days of ripening, ATNC were detected at concentrations of 27 μg NO-N/kg and 64 μg NO-N/kg in the cheeses obtained from milk with and without added NO₃ ^–, respectively. The NO₃ ^– contents of both cheeses were nearly the same, and below 5 mg/kg. The occurrence of NO₂ ^–was not observed. No relationship was found between the NO₃ ^– contents and the contamination of the cheeses by volatile N-nitrosamines. At the beginning of ripening, the cheeses manufactured with added NO₃ ^- showed high levels of ATNC (mean value 5800 μg N-NO/kg with large variations of 570–15210 μg NO-N/kg). These ATNC contents rapidly decreased during the first days of ripening (96%), but decreased much more slowly during the following days. An hypothetical mechanism, attempting to explain the disappearance of ATNC, involving the formation of alkylated species in the cheese was proposed. Received: 30 March 1998 / Revised version: 7 October 1998     

Impact of volume fiber on distribution of thermal stress residual near fiber/epoxy interface using axisymmetric model

Thermal residual stresses are important in composite materials. The aim of this work is the computation of thermal residual stresses by finite element method and the effect of volume fraction on their distribution. In this work, two cases are considered by using an epoxy matrix with respectively glass and carbon fibers with a different volume fiber using an axisymmetric model. From the results of the numerical calculation, it is shown that the stresses are important and thus should be taken into account. The interface is affected by thermal stresses. The normal stresses and shear stress value have an influence on the behavior of the material. Hence, on the performance of composites during service, is an information of significance for the designers.     

Enhancing the sustainability and energy conservation in heritage buildings: The case of Nottingham Playhouse

Today, there is a growing interest in developing energy efficient buildings since it is estimated that buildings account for about 40% of the total primary energy consumption in the world. In relation to existing buildings, energy efficiency retrofits have become an important opportunity to upgrade the energy performance of commercial, public and residential buildings that may reduce the energy consumption, demand and cost. In this paper we cover the energy efficiency deep retrofit process that has been carried out for Nottingham Playhouse theatre building for the aim of enhancing its environmental performance and analysing the energy efficiency gained after implementing certain proposed modifications. It is a nationally protected historic building, listed as Grade II1 on The National Heritage List for England (NHLE). The building has had insulation enhancement, doors modifications, solar energy installations, energy-saving lights, in addition to improved heating and air conditioning system. The paper presents a novel methodology; and its results indicate significant improvements in the building's energy performance which is demonstrated using infrared thermographic images and data logger sensors where significant energy savings to the building's thermal performance are obtained. The energy saving measures have been completed while maintaining the heritage building's general appearance and architectural features, which have received a Commendation Certificate from The Nottingham Civic Society for this achievement.     

Classification of Honey According to Geographical and Botanical Origins and Detection of Its Adulteration Using Voltammetric Electronic Tongue

Main possible honey fraud is the addition of various sugar syrups. But, there are also other types of fraud, such as deception on the geographical and/or botanical origin product. Providing a product of the hive with full authenticity is therefore crucial for the preservation of beekeeping. In this pursuit, voltammetric electronic tongue (VE-tongue) was employed to classify honey samples from different geographical and botanical origins. Furthermore, VE-tongue was used to detect adulterants such as glucose syrup (GS) and saccharose syrup (SS) in honey. The data obtained were analyzed by three-pattern recognition techniques: principal component analysis (PCA), support vector machines (SVMs), and hierarchical cluster analysis (HCA). These methods enabled the classification of 18 honeys of different geographical origins and 7 honeys of different botanical origins. Excellent results were obtained also in the detection of adulterated honey. Therefore, this simple method based on VE-tongue could be useful in the honey packaging and commercialization industry.     

On the reduce of interfacial shear stresses in fiber reinforced polymer plate retrofitted concrete beams

One major problem when using bonded fiber reinforced polymer (FRP) plate is the presence of high interfacial shear stresses near the end of the composite (edge effect) which might govern the failure of the strengthening schedule. It is known that the decrease of plate thickness reduces the magnitude of stress concentration at plate ends. Another way is to use a plate end tapering. In this paper, the analytical solution of interfacial shear stresses obtained has been extended by a numerical procedure using the modal analysis of finite element method (FEM) in a retrofitted concrete (RC) beam with the FRP plate with tapered end, which can significantly reduce the stress concentration. This approach allows taking into consideration the variation of elastic properties of adhesive and plate as well as the complicated geometrical configurations and effects of thermal loads.     

Influence of the deposition conditions on the crystallographic structure and the GaAs refraction index

An experimental study of the influence of deposition conditions of GaAs thin films growth, by radio frequency sputtering method, on the structure and the refraction index has been performed. The X-ray diffraction and spectrophotometer results, with different deposition conditions, are reported.The refraction index depends on the structure, which also depends on four deposition parameters, namely, the self-bias voltage, V_p, the argon pressure, P_Ar, the target-to-substrate distance, d, and the substrate temperature, T_s. Hence, it has been observed that, the index refraction of the films decreases with V_p and T_s and increases essentially with P_Ar.     

Big Data to support sustainable urban energy planning: The EvoEnergy project

Energy sustainability is a complex problem that needs to be tackled holistically by equally addressing other aspects such as socio-economic to meet the strict CO₂ emission targets. This paper builds upon our previous work on the effect of household transition on residential energy consumption where we developed a 3D urban energy prediction system (EvoEnergy) using the old UK panel data survey, namely, the British household panel data survey (BHPS). In particular, the aim of the present study is to examine the validity and reliability of EvoEnergy under the new UK household longitudinal study (UKHLS) launched in 2009. To achieve this aim, the household transition and energy prediction modules of EvoEnergy have been tested under both data sets using various statistical techniques such as Chow test. The analysis of the results advised that EvoEnergy remains a reliable prediction system and had a good prediction accuracy (MAPE  5%) when compared to actual energy performance certificate data. From this premise, we recommend researchers, who are working on data-driven energy consumption forecasting, to consider merging the BHPS and UKHLS data sets. This will, in turn, enable them to capture the bigger picture of different energy phenomena such as fuel poverty; consequently, anticipate problems with policy prior to their occurrence. Finally, the paper concludes by discussing two scenarios of EvoEnergy development in relation to energy policy and decision-making.     

Application of a portable electronic nose system to assess the freshness of Moroccan sardines

In this paper, we propose the investigation and the realisation of an electronic nose system able to evaluate fish freshness in real-time, under the constraints of being suitable for miniaturization and portability. Six tin oxide based Taguchi gas sensors are used to analyse sardine samples stored at 4 °C. A dedicated real-time data acquisition system based on a microcontroller and portable computer have been designed and constructed for this application. Principal component analysis (PCA) and support vector machines (SVMs) results show that the system is able to assess the freshness of sardines stored at 4 °C.     

A Finite Element Analysis for Evaluation of J-Integral in Plates Made of Functionally Graded Materials with a Semicircular Notch

Journal of Failure Analysis and Prevention - This work introduces a numerical investigation using finite element method to evaluate the J-integral at crack tip in titanium boride...