Direct normal irradiation-based approach for determining potential regions for concentrated solar power installations in Morocco

In this study, potential sites for concentrated solar power (CSP) installations in Morocco are investigated based on direct normal irradiation (DNI). The DNI data of four Moroccan sites (Missour, Erfoud, Zagora and Tantan) were collected from different satellite databases (NASA SSE, PV GIS-Helioclim, Climate-SAF PVGIS and Solar Med Atlas). However, it is required to mitigate the risks resulting from uncertainties of satellite-based irradiation data by combining satellite data to ground measurements of at least 1 year. The ground-measured data reported in this work are collected from MHP and MDI meteorological stations installed by IRESEN in collaboration with DLR and ONEE in the framework of the enerMENA project. The Liu and Jordan and the Collares Pereira and Rabl models were also used to determine the monthly and yearly average hourly DNI values. The results of this study suggest that Missour, Erfoud and Zagora represent potential sites for CSP power plants installations, except for Tantan.     

Dynamic characteristics and improved MPPT control of PV generator

This paper presents a mathematical model of photovoltaic (PV) module and gives a strategy to calculate online the maximum power point (MPP). The variation of series and shunt resistor are taken into account in the model and are dynamically identified using the Newton-Raphson algorithm. The effectiveness of the proposed model is verified by laboratory experiments obtained by implementing the model on the dSPACE DS1104 board.     

Multimycotoxin Determination in Tunisian Farm Animal Feed

Mycotoxins presence was evaluated in animal feed marketed in Tunisia for the first time ever. A QuEChERS method was performed to analyze the natural copresence of 22 mycotoxins (enniatins, beauvericin, ochratoxin A, aflatoxins, alternariol monomethyl ether, alternariol, tentoxin, zearalenone, deoxynivalenol, 3‐acetyldeoxynivalenol, 15‐acetyldeoxynivalenol, nivalenol, neosolaniol, diacetoxyscirpenol, T‐2 toxin, and HT‐2 toxin) in 122 Tunisian marketed feed samples, intended for poultry (n = 43), cattle (n = 35), rabbit (n = 12), sheep (n = 16), and horse (n = 16). Analytes detection and quantification were done using both liquid chromatography and gas chromatography coupled to tandem mass spectrometry. The analytical method showed good linearity (R > 0.996) and sensitivity, the limits of quantification ranged from 0.1 ng/g (enniatin A1) to 225 ng/g (3‐acetyldeoxynivalenol). Eighty‐five percent of the analyzed samples were positive. Poultry (n = 43) and rabbit (n = 12) feed samples were the most contaminated. Enniatin B was the most prevalent mycotoxin with values ranged between 0.5 ng/g for horse feed and 40 ng/g for poultry feed, followed by deoxynivalenol detected from 16 ng/g in cattle feed to 250 ng/g in poultry feed. None exceeded the limits set by EU recommendations for animal feed. Mycotoxins co‐occurrence was observed at most by five different mycotoxins (26%) and up to eight mycotoxins was recorded in 5% of samples. Furthermore, a relatively high copresence rate of different fusariotoxins was registered. Even if no toxicological concern was clearly revealed, the contamination is a real fact and will probably present influence on meat production and on food safety.     

Low‐voltage high‐performance current mirrors: Application to linear voltage‐to‐current converter

Current mirror is one of the basic building blocks of analog VLSI systems. For high‐performance analog circuit applications, the accuracy and bandwidth are the most important parameters to determine the performance of the current mirror. This paper presents an efficient implementation of a CMOS current mirror suitable for low‐voltage applications. This circuit combines a shunt input feedback, a regulated cascade output and a differential amplifier to achieve low input resistance, high accuracy and high output resistance. A comparison of several architectures of this scheme based on different architectures of the amplifier is presented. The comparison includes: input impedance, output impedance, accuracy, frequency response and settling time response. These circuits are validated with simulation in 0.18µm CMOS TSMC of MOSIS. In this paper, a linear voltage to current converter, based on the adapted current mirror, is proposed. Its static and dynamic behaviour is presented and validated with the same technology. Copyright © 2009 John Wiley & Sons, Ltd.     

Low‐latency retransmission control in a wireless communication system for plant instrumentation and control

When wireless communication technology is applied to plant instrumentation and control systems, it is important to ensure real‐time transmission and high reliability of the wireless communication system. However, the wireless communication system is prone to more frequent occurrence of transmission errors than a wired communication system, so that generally retransmission is implemented generically. To reduce retransmission latency, we propose a method of low‐latency retransmission control, which is a data block transmission method with multi‐redundant media access control layer (MAC) headers, to implement a wireless communication system for plant instrumentation and control. We carried out system tests using prototypes with the proposed methods, that is, data block transmission with multi‐redundant MAC headers. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Symmetric routing in DHT overlays

In this paper, we propose to extend the DHT topology to a bidirectional graph to provide a super-peer based lookup algorithm and a scalable search support. We consider routing algorithms for a bidirectional variant of the DHT network and show how the resulting structure extends the search region and provides an efficient resource lookup service at a very little additional cost.     

Evaluation of nutritional status in persons with spinal cord injury: a prerequisite for successful rehabilitation

A minority of patients with acute pulmonary embolism (PE) show failure of resolution when assessed by serial ventilation/perfusion (V/Q) radionuclide lung imaging. The fibrinolytic systems were studied in six such patients (group I), and in 11 patients in whom PE had resolved (group II), together with 17 healthy control subjects. Assays of the fibrinolytic system included euglobulin clot lysis times (ECLT), tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1). Euglobulin clot lysis times were not prolonged in the unresolved PE group, but were significantly longer in patients in group II when compared to control subjects (P < 0.03). This could not be explained either on the basis of tPA levels, which were higher in group II when compared to group I (P < 0.05) and control subjects (P < 0.02), or on the basis of PAI-1 levels which did not differ significantly between the three groups. Our inability to demonstrate derangements of fibrinolysis in the patients with unresolved PE makes defective fibrinolysis an unlikely aetiological factor in the persistence of thrombosis in these patients.