Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Synthesis, structure and properties of doped Bi2O3

Abstract: Oxide ion conductors have been increasingly studied for many years because of their application in devices with high economical interest such as solid oxide fuel cells (SOFC), oxygen sensors, dense ceramic membranes for oxygen separation, and membrane reactors for oxidative catalysis. Bismuth oxides present polymorph forms, such as δ-, β- or γ-Bi 2 O 3 , with great potential for such applications, alone or in combination with other oxides. The present study investigates the influence of selected ions (Fe 3+ , Sb 3+ /Sb 5+ , and Ta 5+ ), introduced as dopant in α-Bi 2 O 3 and their effect on the structure and properties of the oxide polymorph forms obtained at high temperature. The molar ratio was Bi 2 O 3 :M x O y 0.95:0.05 where M = Fe 2 O 3 , Sb 2 O 3 or Ta 2 O 5 , respectively. The structural changes of α-Bi 2 O 3 were analysed by powder X-ray diffraction, SEM/EDX analysis and infrared spectroscopy. The structural changes are correlated with bulk ceramic characteristics (density, porosity) and their electrical behaviour versus temperature. The presence of some dopants (antimony and tantalum) on bismuth sites enlarges and enhances the stability of the polymorph forms, which is relevant to potential application.

Tracing the influence of Mediterranean climate on Southeastern Europe during the past 350,000 years

Abstract: Loess-palaeosol sequences are valuable archives of past environmental changes. Although regional palaeoclimatic trends and conditions in Southeastern Europe have been inferred from loess sequences, large scale forcing mechanisms responsible for their formation have yet to be determined. Southeastern Europe is a climatically sensitive region, existing under the strong influence of both Mediterranean and continental climates. Establishment of the spatial and temporal evolution and interaction of these climatic areas is essential to understand the mechanisms of loess formation. Here we present high-resolution grain-size, environmental magnetic, spectrophotometric and geochemical data from the Stalac section in the Central Balkans (Serbia) for the past ~350,000 years. The goal of this study is to determine the influence of the Mediterranean climate during this period. Data show that the Central Balkans were under different atmospheric circulation regimes, especially during Marine Isotope Stages 9 and 7, while continental climate prevailed further north. We observe a general weakening of the Mediterranean climate influence with time. Our data suggest that Marine Isotope Stage 5 was the first interglacial in the Central Balkans that had continental climate characteristics. This prominent shift in climatic conditions resulted in unexpectedly warm and humid conditions during the last glacial.

A Quick Method for Estimating the Propagation Direction of Coronal Mass Ejections Using STEREO-COR1 Images

Abstract: We describe here a method to obtain the position of a coronal moving feature in a three-dimensional coordinate system based on height – time measurements applied to STEREO data. By using the height – time diagrams from the two SECCHI-COR1 coronagraphs onboard STEREO, one can easily determine the direction of propagation of a coronal mass ejection (i.e., if the moving plasma is oriented toward or away from the Earth). This method may prove to be a useful tool for space weather forecasting by easily identifying the direction of propagation as well as the real speed of the coronal mass ejections.

Is the Tourism Sector Supportive of Economic Growth? Empirical Evidence on Romanian Tourism:

Abstract: This paper studies the long-run relationships between tourism expansion and economic growth in Romania during the period 1988–2009. The empirical evidence highlights the nature of causal relationships, if any, between domestic travel and tourism spending, internal travel and tourism consumption, the gross domestic product annual growth rate and the real exchange rate. The paper uses the cointegration method and Granger causality analysis based on the vector error correction model (VECM) and impulse functions. The findings suggest that there are Granger causality relationships running from tourism expansion to economic growth, which sustains the tourism-led growth hypothesis (TLGH). These results emphasize the need for more consistent tourism development plans and strategies to be implemented at national and regional levels by the governmental authorities.