Problems of village electrification based on PV systems in Romania: Individual solar home systems for settlements in the Cerna Valley

The autonomous PV systems cover a wide area of the applications that can be developed in the country, in places far from the national grid and with a low demand of electric power. The electrification of homes and farms in rural areas by using PV systems would contribute to improving the inhabitants' social, economic and cultural standard.In Romania, it is estimated that there are about 10,000 homes, farms and schools located in more than 500 settlements which could be electrified by using PV systems. The individual solar home systems would allow each user to adjust his own electricity consumption according to weather variations. A major problem in the development of these systems is the identification of the optimum technical and economic solutions as well as of the main financing sources. The paper aims to present the technical, economic and social problems involved by the implementation of such a project of PV-based electrification in Romania, presenting the particular case of two settlements (Scarisoara and Prisacina) located in the Cerna Valley - the Banat Mountains.     

X-ray absorption fine structure investigations on heat-treated Cr-doped titania thin films

Chromium-doped titanium oxide thin films were investigated in the as-deposited state and after thermal treatment (723 K for 3 h in air). X-ray diffraction data revealed an improvement in film crystallinity induced by the thermal treatment. Extended X-ray absorption fine structure data revealed similar atomic neighboring around Cr atoms in both as-deposited and annealed samples. A lattice contraction of ~ 2% is observed in the annealed samples. The 67% enhancement of the amplitude of the Cr 1 s X-ray absorption fine structure pre-edge peak after thermal treatment, which is a sign of “dipole-forbidden” 1 s → 3 d transitions, suggests strong alteration in the number of Cr 3 d vacancies, in spite of similar Cr local environment in the two kinds of investigated samples. We discuss here the Cr⁺ → Cr⁴⁺ and Cr²⁺ → Cr⁶⁺ changes induced by thermal treatment, and/or the evolution in local structures without inversion center.Refractive index dispersion spectra in the visible wavelength domain allowed us to compute the values of the dispersion energy, the single-oscillator energy and the coordination number of Ti atoms in both as-deposited and annealed samples.     

Adjusting Some Properties of Poly(methacrylic acid) (Nano)Composite Hydrogels by Means of Silicon-Containing Inorganic Fillers

The present work aims to show how the main properties of poly(methacrylic acid) (PMAA) hydrogels can be engineered by means of several silicon-based fillers (Laponite XLS/XLG, montmorillonite (Mt), pyrogenic silica (PS)) employed at 10 wt% concentration based on MAA. Various techniques (FT-IR, XRD, TGA, SEM, TEM, DLS, rheological measurements, UV-VIS) were used to comparatively study the effect of these fillers, in correlation with their characteristics, upon the structure and swelling, viscoelastic, and water decontamination properties of (nano)composite hydrogels. The experiments demonstrated that the nanocomposite hydrogel morphology was dictated by the way the filler particles dispersed in water. The equilibrium swelling degree (SDe) depended on both the pH of the environment and the filler nature. At pH 1.2, a slight crosslinking effect of the fillers was evidenced, increasing in the order Mt < Laponite < PS. At pH > pKa_MAA (pH 5.4; 7.4; 9.5), the Laponite/Mt-containing hydrogels displayed a higher SDe as compared to the neat one, while at pH 7.4/9.5 the PS-filled hydrogels surprisingly displayed the highest SDe. Rheological measurements on as-prepared hydrogels showed that the filler addition improved the mechanical properties. After equilibrium swelling at pH 5.4, G’ and G” depended on the filler, the Laponite-reinforced hydrogels proving to be the strongest. The (nano)composite hydrogels synthesized displayed filler-dependent absorption properties of two cationic dyes used as model water pollutants, Laponite XLS-reinforced hydrogel demonstrating both the highest absorption rate and absorption capacity. Besides wastewater purification, the (nano)composite hydrogels described here may also find applications in the pharmaceutical field as devices for the controlled release of drugs.     

Towards Long Lifetime Battery: AI-Based Manufacturing and Management

Technologies that accelerate the delivery of reliable battery-based energy storage will not only contribute to decarbonization such as transportation electrification, smart grid,but also strengthen the battery supply chain. As battery inevitably ages with time, losing its capacity to store charge and deliver it efficiently. This directly affects battery safety and efficiency,making related health management necessary. Recent advancements in automation science and engineering raised interest in A...     

Knowledge-Guided Data-Driven Model With Transfer Concept for Battery Calendar Ageing Trajectory Prediction

<正>Dear Editor, Lithium-ion(Li-ion) battery has become a promising source to supply and absorb energy/power for many energy-transportation applications. However, Li-ion battery capacity would inevitably degrade over time, making its related ageing prediction necessary.     

Monopolar needle electrode spatial recording characteristics

The recording characteristics of the monopolar needle in three dimensions have not been well established. A simple spherical recording territory is commonly assumed with the very tip proposed to have a greater spatial recording sensitivity by some authors. We demonstrate by enlarged physical modeling in a homogeneous volume conductor that the recorded amplitude diminishes more gradually radially away from the conical surface than distally past the tip or proximal to the insulation edge. The sensitivity over the exposed metallic surface is found to be uniformly proportional to the area, which results in relatively less sensitivity at the tip than the middle and proximal portions of the conical recording surface. The overall spatial amplitude recording characteristics can be better described by an apple shape than a sphere, centered at the midportion of the exposed conical surface. A better appreciation of the actual spatial recording characteristics of the monopolar needle electrode can result in more accurate physiologic interpretations of quantitative motor unit analysis.     

Concentric needle electrode duration measurement and uptake area

Motor unit action potentials (MUAPs) were recorded with a standard concentric needle electrode inserted into the right biceps brachii muscle with different angular orientations of the beveled recording surface to the muscle fibers. Contrary to the predictions from computer simulations, the MUAP duration remained constant during needle rotation. This finding is used to reexamine the previous assumptions regarding the concentric needle's spatial uptake recording territory and the implications with respect to MUAP duration measurements.     

Some physical studies on thexBeO(1 −x)V2O5 system

The results of X-ray analysis, electron microscope studies, nuclear magnetic resonance, electron paramagnetic resonanace and infrared absorption spectra performed on thexBeO(1 –x)V₂O₅ system are reported. These suggest that, unlike previous statements, V₂O₅-BeO does not form solid solutions.     

The effects of electroconvulsant shocks on phagocytic activity and on phagocytic response

The influence of a single or several subsequent convulsant electroshocks at different time laps (2-4 day), over a month, on the phagocytic activity was studied on seven dogs. The electroconvulsant shock was performed with bitemporal electrodes, at a liminal electric power. Phagocytosis was studied in vitro with amidon particles in whole blood, incubated 1h at 37 degrees C. After 4 hours the phagocytosis increases in all animals and remains higher for 12 days. Later on the repeated shocks produce very different changes of the phagocytic activity, depending, not only on the stressor agent, but also on the animal particular reactivity, conditioned genetically and by its individual history.     

On the buckling of a column in an elastic medium

One deals with the buckling of a cantilever column in an elastic medium by the aid of the differential eqns (2), (2′) with bilocal conditions (3), (3′). Introducing the conventional load (4), one considers the three cases P_cr < P₀, P_cr = P₀ and P_cr > P₀ and one determines the corresponding characteristics eqns (8″), (12), (15″). The reduced critical load P_cr/P₎ and the reduced critical length l_cr/l are listed in a table and plotted into diagrams for various values of an adimensional magnitude bl. One obtains also the asymptotic formulae (16), (16′).