Toward equilibrium ground state of charge density waves in rare-earth tritellurides

We show that the charge density wave (CDW) ground state below the Peierls transition temperature, $T_{CDW}$, of rare-earth tritellurides is not at its equilibrium value, but depends on the time where the system was kept at a fixed temperature below $T_{CDW}$. This ergodicity breaking is revealed by the increase of the threshold electric field for CDW sliding which depends exponentially on time. We tentatively explain this behavior by the reorganization of the oligomeric (Te$_x$)$^{2-}$ sequence forming the CDW modulation.Comment: 10 pages, 5 figures, accepted in PR

One step protocol and green synthesis of 2-N,N-dimethylamino-3-alkyl(aryl)-2-oxido-1- hydro-2-benzo[1,3,2]diazaphosphinine-4-one derivatives

ABSTRACT. 2-N,N-dimethylamino-2-oxido-3-alkyl(aryl)-1-hydro-2-benzo[1,3,2]diazaphosphinin-4-one (2) derivatives  are synthesized by one pot reaction by reacting equimolar quantities of anthranilic acid, primary amine, and N,N-dimethylphosphoramic dichloride under reflux of ethanol with good yields. The structure of the compounds were established on the basis of their infrared, nuclear magnetic resonance spectral data (1H NMR, 13C NMR and 31P NMR), mass spectrometry, and elemental analysis.   KEY WORDS: Anthranilic acid, N,N-Dimethylphosphoramic dichloride, Diazaphosphinine Bull. Chem. Soc. Ethiop. 2022, 36(4), 859-864.                                                               DOI: https://dx.doi.org/10.4314/bcse.v36i4.11                                                   &nbsp

ANETAC: Arabic named entity transliteration and classification dataset

In this paper, we make freely accessible ANETAC, our English-Arabic named entity transliteration and classification dataset that we built from freely available parallel translation corpora. The dataset contains 79, 924 instances, each instance is a triplet (e, a, c), where e is the English named entity, a is its Arabic transliteration and c is its class that can be either a Person, a Location, or an Organization. The ANETAC dataset is mainly aimed for the researchers that are working on Arabic named entity transliteration, but it can also be used for named entity classification purposes. This dataset was developed and used as part of a previous research study done by Hadj Ameur et al. [1]

Genetic Algorithms for Optimal Reactive Power Compensation of a Power System with Wind Generators based on Artificial Neural Networks

In this paper, we develop a method to maintain an acceptable voltages profile and minimization of active losses of a power system including wind generators in real time. These tasks are ensured by acting on capacitor and inductance benches implemented in the consuming nodes. To solve this problem, we minimize an objective function associated to active losses under constraints imposed on the voltages and the reactive productions of the various benches. The minimization procedure was realised by the use of genetic algorithms (GA). The major disadvantage of this technique is that it requires a significant computing time thus not making it possible to deal with the problem in real time. After a training phase, a neural model has the capacity to provide a good estimation of the voltages, the reactive productions and the losses for forecast curves of the load and the wind speed, in real time

Analysis Techniques of Polymeric Encapsulant Materials for Photovoltaic Modules: Situation and Perspectives

AbstractThe properties of the encapsulant are critical to the long-term performance of photovoltaic (PV) modules under the influence of sunlight including UV, elevated temperature, humidity and diffusion of oxygen. Encapsulation process represents about 40% of the whole PV module cost. The introduction of new non-EVA encapsulant material type ″Low-Cost, High-Performance″ should provide a solution to outdoor yellowing degradation problems. The emerging encapsulant materials exhibit a good compatibility with emerging PV solar cells for long term durability. This new generation of encapsulant materials has the advantage to improve the PV module performances and long term durability for specific climate like desert regions. This scientific contribution presents an overview of the different encapsulant materials currently on the market, the general requirements of the emerging encapsulant materials and characterizations techniques for degradation, diagnostic and reliability lifetime estimation in the framework of Algerian renewable energy strategy

EU Dairy Sector: Impact of Luxemburg Reform, EU Enlargement and Trade Negotiations

The EU dairy sector is facing a period of significant changes that are due to three major decisions: the EU enlargement, the Luxembourg reform and on-going WTO negotiations. To evaluate the impact of such changes we developed a model of the EU and world dairy industry. The model is composed of two modules that interact: a milk and beef supply module and a dairy industry module. In this paper we present the model and focus on elements that are crucial for a better understanding of the impact of reforms: quota rents in the EU, evolution of production in the new member states and trade policy.agricultural policy, dairy industry, partial equilibrium model, International Relations/Trade, C21, Q13, Q18,

Propriétés physicochimiques et rhéologiques d’un mélange aqueux de biopolymères et d’un tensioactif non ionique

Dans ce travail, on s‟intéresse à l‟effet des concentrations du xanthane, du caséinate de sodium et du tween 20 sur les propriétés rhéologiques, zétamétriques et de surface de leurs mélanges, dans un milieu aqueux à pH neutre. Il a été mis en évidence, à l‟issue de l‟utilisation de la méthodologie des plans d‟expériences, de l‟existence des interactions répulsives de ségrégation entre les biopolymères, générant un affaiblissement du module de conservation viscoélastique, G‟o et par la même une fragilisation de la structure du système colloïdal. Dans cette situation, il a été observé que le potentiel zêta diminue, ce qui laisse supposer que les interactions répulsives électrostatiques entre les deux espèces anioniques ne sont pas responsables du relâchement de la structure. Par ailleurs, il a été observé que la tension de surface du mélange dépend essentiellement de la concentration du tween 20.Mots clés :Biopolymères - Tween 20 – Rhéologie - Tension de surface - Potentiel zêta