Reliability Analysis of Photovoltaic Systems for Specific Applications

This contribution is dedicated to the analysis of a reliable PV system for specific applications. The reliability study was based on: (1) the RAMS (Reliability, Availability, Maintenance, and Safety) model applied to a PV system by using a simulation SYNTHESIS platform developed by ReliaSoft, and (2) the simulation of the PV system using the SYNTHESIS platform and TM-21 Calculator software developed by ENERGY STAR. The objective of this analysis was to obtain a more stable and long-lasting operation of a PV system regarding reliability, maintainability, availability and degradation of the system

Fiscal policy – an instrument for achieving economic and social balance

The fiscal policy construction developped at national level is focused on the maintenance of the macroeconomic stability process in order to achieve the nominal and real convergence criteria concerning the membership of the Romanian economy to the European Union integrated monetary space. The orientation of the fiscal national policy is subdue to some major constraints regarding her capacity of ensuring the external sustenance, of developping the non-inflation process, of forming and consolidating the financing resources necessary to the accomplishment of the post-adhesion engagements assumed by Romania as a member state of the European Union.Fiscal policy, economic crisis, fiscal policy, to stabilize the economy

Interacciones moleculares entre los aniones complejos de los metales de transición y bases orgánicas nitrogenadas

Tesis inédita de la Universidad de Madrid, Facultad de Ciencias, Sección de Químicas, leída en 1972.Universidad de MadridTRUEProQuestpu

Elastographie en temps réel – impact de la réponse d’anélasticité

Université de Médecine et de Pharmacie ”Victor Babes”, Timisoara, Roumanie The IVth Congress of Radiology and Medical Imaging of the Republic of Moldova with international participation, Chisinau, May 31 – June 2, 2018Introduction: L’élastographie mammaire est une technique récente utilisée en complément de l’échographie mammaire dans le dépistage du cancer du sein. L’élastographie fournit non seulement des informations qualitatives (carte à codage de couleur), ainsi que quantitative, liée au rapport d’élasticité du nodule versus le tissu adipeux (FLR). À la lumière de la qualité, il y a controverse sur la valeur de discrimination entre les lésions bénignes et malignes. Actuellement, la limite utilisée dans notre centre est la valeur médiane de 4,88, validée sur une étude comparative avec l’examen histopathologique, une valeur qui assure une sensibilité de 86,5% et une spécificité de 90,4% Matériel et méthodes: L’étude a inclu 344 femmes, âgées de 19 à 76 ans, avec des pathologies mammaires chirurgicales, qui ont eu un résultat histopathologique clair et, dans certains cas, un résultat immunohistochimique clair. Résultats: Sur le total de 344 cas, ont été diagnostiqués lésions bénignes en 186 (54,1%), le cancer du sein dans 158 cas (45,9%). Lorsque nous avons examiné la valeur FLR, on a eu la stratification du risque suivant: faible risque dans 166 cas, 38 cas avec risque intermédiaire et à haut risque 138 cas. La sensibilité et la spécificité de cette stratification considérée isolée, sans l’information fournie par l’échographie 2B, est 92,4% et respectivement 83,9%. Le système conventionnel BIRADS-US n’avait qu’une sensibilité de 75,6%, avec une spécificité de 69,9%. Contrairement à cela, un nombre important de cas classés comme intermédiaires, 97 cas (catégorie BIRADS 4 a), ont été réorganisés dans l’autre catégorie de risque, alors quand ils ont été soumis à l’évaluation élastographique, 23 ont été attribués à un groupe à haut risque en raison de l’anélasticité et 26 ont été attribués à classe de risque faible parce que l’élasticité était présente. Seuls 48 cas sont restés dans la catégorie intermédiaire. Conclusions: Évidemment, l’élastographie apporte un plus pour l’échographie classique, en réduisant le nombre de résultats faux positifs et faux négatifs par rapport à l’échographie classique

NEW DISPOSITIONS WITH REGARD TO FILIATION

The new Romanian Civil Code1 is a milestone for the profound reform of our judiciary as regards the matter of private law relationships, on the grounds of valuating the national and international experience.2 The novelties are represented, mainly, by the review of certain legal institutions and promotion of new principles and solutions. On this backdrop, the regulation of family relationships also received a new face. The present task is devoted to highlighting the amendments interfered in the matter of filiation, by presenting the systematization method of legal regulations and the critical analysis of its content

PRIMARY REGIME AS REGULATED BY THE NEW ROMANIAN CIVIL CODE

The regulation of patrimonial relations between spouses shall find a modern approach in the new Civil Code1, according to the legislation of the European countries, which shall provide any family the possibility to choose its matrimonial regime applicable to the concrete situation and interests.Moreover, in order to protect the interest of the family and its life environment, the new Civil Code establishes a set of general provisions, applicable to any family, irrespective of the matrimonial regime chosen by the spouses to regulate their patrimonial relations. Even though the legal text summons those norms under the title of „Common provisions”2, the doctrine assumed the name most used in the law systems having similar provisions, namely the „primary regime”.Among the objectives of this work it is also the analysis of provisions setting up the primary regime applicable to spouses in the new Romanian Civil Code, and also its implications on the protection of the family life from a patrimonial perspective

Numerical Modelling and Digitalization Analysis for a Photovoltaic Pumping System Placed in the South of Romania

The authors studied a working off-grid type photovoltaic (PV) pumping system for irrigation use. The methodology was based on digitalization analysis and numerical modeling as a preliminary stage. A mathematical model of the PV pumping installation considered the determination of the characteristic equations for all its components. These have been used together with the SISIFO simulation software to achieve the performances of the mechanical and electrical components of an advanced PV pumping system. Its global performance features, namely the monthly energy yield, monthly pumping yield, and monthly total performances (energy and flow rate) were introduced. Digital platform (DP) for PV systems characterized by three advanced technologies—machine learning (ML), digital twin (DT) and artificial intelligence (AI) was developed. The simulation results were discussed for a specific case study conducted for a location in the Southern Romania regarding the irrigation potential, taking into account the main meteorological parameters: solar irradiance and ambient temperature, related to the site. The AI approach was implemented to achieve an optimum operation of the PV pumping system by the use of the maximum power point tracking (MPPT) method and the MATLAB/Simulink software. A unified development of all the components of the PV pumping system using the SISIFO simulation software was established by the authors, with major implications in the development of solar PV installations on large-scale

Complex Investigation of High Efficiency and Reliable Heterojunction Solar Cell Based on an Improved Cu2O Absorber Layer

This study is aimed at increasing the performance and reliability of silicon-based heterojunction solar cells with advanced methods. This is achieved by a numerical electro-optical modeling and reliability analysis for such solar cells correlated with experimental analysis of the Cu2O absorber layer. It yields the optimization of a silicon tandem heterojunction solar cell based on a ZnO/Cu2O subcell and a c-Si bottom subcell using electro-optical numerical modeling. The buffer layer affinity and mobility together with a low conduction band offset for the heterojunction are discussed, as well as spectral properties of the device model. Experimental research of N-doped Cu2O thin films was dedicated to two main activities: (1) fabrication of specific samples by DC magnetron sputtering and (2) detailed characterization of the analyzed samples. This last investigation was based on advanced techniques: morphological (scanning electron microscopy—SEM and atomic force microscopy—AFM), structural (X-ray diffraction—XRD), and optical (spectroscopic ellipsometry—SE and Fourier-transform infrared spectroscopy—FTIR). This approach qualified the heterojunction solar cell based on cuprous oxide with nitrogen as an attractive candidate for high-performance solar devices. A reliability analysis based on Weibull statistical distribution establishes the degradation degree and failure rate of the studied solar cells under stress and under standard conditions

Corrosion Resistance of AISI 442 and AISI 446 Ferritic Stainless Steels as a Support for PEMWE Bipolar Plates

Cost reduction in bipolar plates in proton exchange membrane water electrolyzers has previously been attempted by substituting bulk titanium with austenitic stainless steels protected with highly conductive and corrosion-resistant coatings. However, austenitic steels are more expensive than ferritic steels due to their high nickel content. Herein we report on the corrosion resistance of two high chromium ferritic stainless steels, AISI 442 and AISI 446, as an alternative material to manufacture bipolar plates. Electrochemical corrosion tests have shown that AISI 442 and AISI 446 have similar corrosion resistance, while AISI 446 reveals more noble corrosion potential and performs better during potentiostatic stress tests. The current density obtained during polarization at 2 V versus the standard hydrogen electrode (SHE) is 3.3 mA cm−2, which is more than two times lower than on AISI 442. Additionally, surface morphology characterization demonstrates that in contrast to AISI 442, AISI 446 is not sensitive to intercrystalline or pitting corrosion. Moreover, EDX energy dispersion analysis of AISI 446 reveals no differences in the chemical composition of the surface layer compared to the base material, as a confirmation of its high corrosion resistance. The results of this work open up the perspective of replacing austenitic stainless steels with less expensive ferritic stainless steels for the production of components such as bipolar plates in proton exchange membrane water electrolyzers