Geothermal development in Romania

Exploration for geothermal resources began in Romania in the early 1960s, based on a detailed geological exploration program for hydrocarbon resources that had a capacious budget and enabled the identification of eight geothermal areas. Over 200 wells drilled to depths between 800 and 3500 m have indicated the presence of low-enthalpy geothermal resources (40–120 °C). Completion and experimental production from over 100 wells during the past 25 years has led to the evaluation of the exploitable heat resources of the geothermal reservoirs. The proven reserves, with the wells that have already been drilled, amount to about 200,000 TJ for 20 years. The main geothermal systems discovered on Romanian territory are in porous permeable formations such as sandstones and siltstones (Western Plain and the Olt Valley) or in fractured carbonate formations (Oradea, Bors, and north of Bucharest). The total thermal capacity of the existing wells is about 480 MW_t (for a reference temperature of 25 °C). Only 152 MW_t of this potential is currently being exploited, from 96 wells (35 of which are used for health and recreational bathing), producing hot water in the temperature range 45–115 °C. In 2002 the annual energy utilisation from these wells was about 2900 TJ, with a capacity factor of 0.6. More than 80% of the wells are artesian producers, 18 wells require anti-scaling chemical treatment and six are reinjection wells. During the period 1995–2002, 15 exploration-production geothermal wells were drilled and completed, two of which were dry holes. Drilling was financed by the geological exploration fund of the State Budget, to depths varying between 1500 and 3500 m. Progress in the direct utilisation sector of geothermal resources has been extremely slow because of the difficulties encountered during the transition period from a centrally planned to a free-market economy; geothermal production is at present far below the level that could be expected from its assessed potential, with geothermal operations lagging behind in technology. The main obstacle to geothermal development in Romania is the lack of domestic investment capital. In order to stimulate the interest of potential investors from developed countries and to comply with the requirements of the large international banks, an adequate legal and institutional framework has been created, adapted to a market-oriented economy.     

Environmental Enrichment Decreases Asphyxia-Induced Neurobehavioral Developmental Delay in Neonatal Rats

Perinatal asphyxia during delivery produces long-term disability and represents a major problem in neonatal and pediatric care. Numerous neuroprotective approaches have been described to decrease the effects of perinatal asphyxia. Enriched environment is a popular strategy to counteract nervous system injuries. The aim of the present study was to investigate whether enriched environment is able to decrease the asphyxia-induced neurobehavioral developmental delay in neonatal rats. Asphyxia was induced in ready-to-deliver mothers by removing the pups by caesarian section after 15 min of asphyxia. Somatic and neurobehavioral development was tested daily and motor coordination weekly. Our results show that rats undergoing perinatal asphyxia had a marked developmental delay and worse performance in motor coordination tests. However, pups kept in enriched environment showed a decrease in the developmental delay observed in control asphyctic pups. Rats growing up in enriched environment did not show decrease in weight gain after the first week and the delay in reflex appearance was not as marked as in control rats. In addition, the development of motor coordination was not as strikingly delayed as in the control group. Short-term neurofunctional outcome are known to correlate with long-term deficits. Our results thus show that enriched environment could be a powerful strategy to decrease the deleterious developmental effects of perinatal asphyxia.     

pH‐Responsive PEGylated nanoparticles based on amphiphilic polyaspartamide: preparation,physicochemical characterization and in vitro evaluation

A series of amphiphilic graft copolymers based on polyaspartamide were synthesized by successive aminolysis reactions of polysuccinimide using 2‐diisopropylaminoethyl (DIP), O‐(2‐aminoethyl)‐O′‐methylpolyethylene glycol (PEG) and lauryl amine as pH‐sensitive, hydrophilic and hydrophobic groups, respectively. The pH‐dependent self‐assembly behavior of the aqueous copolymer solution was investigated. Nano‐aggregation, which was induced by a hydrophilic/hydrophobic shift of the DIP group in solution, occurred at a pH in the vicinity of the pK_a of the DIP group. The mean diameter of the nano‐aggregate could be modulated by changing the compositions of both pendants. The mean diameter of the nanoparticles increased with increasing solution pH from 6.5 to 8. The dissolution of paclitaxel into these amphiphilic nanoparticles was attempted and the pH‐dependent release behavior was examined using a solvent‐casting method. The results showed a significantly faster release of paclitaxel at pH = 6.5, which is a tumoral acidic pH, than at neutral physiological pH. These pH‐sensitive PEGylated polyaspartamide derivatives have potential use as a tumor‐targeting delivery system.     

A Single Sign-On Infrastructure for Science Gateways on a Use Case for Structural Bioinformatics

Structural bioinformatics applies computational methods to analyze and model three-dimensional molecular structures. There is a huge number of applications available to work with structural data on large scale. Using these tools on distributed computing infrastructures (DCIs), however, is often complicated due to a lack of suitable interfaces. The MoSGrid (Molecular Simulation Grid) science gateway provides an intuitive user interface to several widely-used applications for structural bioinformatics, molecular modeling, and quantum chemistry. It ensures the confidentiality, integrity, and availability of data via a granular security concept, which covers all layers of the infrastructure. The security concept applies SAML (Security Assertion Markup Language) and allows trust delegation from the user interface layer across the high-level middleware layer and the Grid middleware layer down to the HPC facilities. SAML assertions had to be integrated into the MoSGrid infrastructure in several places: the workflow-enabled Grid portal WS-PGRADE (Web Services Parallel Grid Runtime and Developer Environment), the gUSE (Grid User Support Environment) DCI services, and the cloud file system XtreemFS. The presented security infrastructure allows a single sign-on process to all involved DCI components and, therefore, lowers the hurdle for users to utilize large HPC infrastructures for structural bioinformatics.     

Rapid Homology Search with Neighbor Seeds

Using a seed to rapidly "hit" possible homologies for further scrutiny is a common practice to speed up homology search in molecular sequences. It was shown that a collection of higher weight seeds have better sensitivity than a single lower weight seed at the same speed. However, huge memory requirements diminish the advantages of high weight seeds. This paper describes a two-stage extension method, which simulates high weight seeds with modest memory requirements. By drawing upon the previously studied ideas of vector seed and multiple seeds, we introduce neighbor seeds, which are implemented using two-stage extension. Neighbor seeds provide the flexibility to maximize the independence between the seeds, which is a well-known criterion for optimizing sensitivity. A major advantage of neighbor seeds is that they all rely on the same pre-built database index. Based on considerations of sensitivity and biological adequacy, different neighbor seeds can be used for different queries without rebuilding the index. The paper also discusses some other practical techniques to reduce memory usage.     

An Efficient Quantum Algorithm for the Hidden Subgroup Problem in Nil-2 Groups

In this paper we show that the hidden subgroup problem in nil-2 groups, that is in groups of nilpotency class at most 2, can be solved efficiently by a quantum procedure. The algorithm is an extension of our earlier method for extraspecial groups in Ivanyos et al. (Proceedings of the 24th Symposium on Theoretical Aspects of Computer Science (STACS), vol. 4393, pp. 586–597, 2007), but it has several additional features. It contains a powerful classical reduction for the hidden subgroup problem in nilpotent groups of constant nilpotency class to the specific case where the group is a p-group of exponent p and the subgroup is either trivial or cyclic. This reduction might also be useful for dealing with groups of higher nilpotency class. The quantum part of the algorithm uses well chosen group actions based on some automorphisms of nil-2 groups. The right choice of the actions requires the solution of a system of quadratic and linear equations. The existence of a solution is guaranteed by the Chevalley-Warning theorem, and we prove that it can also be found efficiently.     

Infrared evanescent-absorption spectroscopy with chalcogenide glass fibers

We have used telluride glass fibers fabricated in house to measure the evanescent-absorption spectra of water, methanol, ethanol, isopropanol, acetone, ethanoic acid, hexane, and chloroform. Furthermore, detection limits of less than 2 vol. % solute were obtained for mixtures of water and methanol, ethanol, isopropanol, acetone, and ethanoic acid. Techniques to reduce the detection limits are discussed.