Quiescent consistency: Defining and verifying relaxed linearizability

Concurrent data structures like stacks, sets or queues need to be highly optimized to provide large degrees of parallelism with reduced contention. Linearizability, a key consistency condition for concurrent objects, sometimes limits the potential for optimization. Hence algorithm designers have started to build concurrent data structures that are not linearizable but only satisfy relaxed consistency requirements. In this paper, we study quiescent consistency as proposed by Shavit and Herlihy, which is one such relaxed condition. More precisely, we give the first formal definition of quiescent consistency, investigate its relationship with linearizability, and provide a proof technique for it based on (coupled) simulations. We demonstrate our proof technique by verifying quiescent consistency of a (non-linearizable) FIFO queue built using a diffraction tree. © 2014 Springer International Publishing Switzerland

A practical and user-friendly toxicity classification system with microbiotests for natural waters and wastewaters

Various types of toxicity classification systems have been elaborated by scientists in different countries, with the aim of attributing a hazard score to polluted environments or toxic waste-waters or of ranking them in accordance with increasing levels of toxicity. All these systems are based on batteries of standard acute toxicity tests (several of them including chronic assays as well) and are therefore dependent on the culturing and maintenance of live stocks of test organisms. Most systems require performance of the bioassays; on dilution series of the original samples, for subsequent calculation of L(E C50 or threshold toxicity values. Given the complexity and costs of these toxicity measurements, they can only be applied in well-equipped and highly specialized laboratories, and none of the classification methods so far has found general acceptance at the international level. The development of microbiotests that are independent of continuous culturing of live organisms has stimulated international collaboration. Coordinated at Ghent University, Belgium, collaboration by research groups from 10 countries in central and eastern Europe resulted in an alternative toxicity classification system that was easier to apply and substantially more cost effective than any of the earlier methods. This new system was developed and applied in the framework of a cooperation agreement between the Flemish community in Belgium and central and eastern Europe. The toxicity classification system is based on a battery of (culture-independent) microbiotests and is particularly suited for routine monitoring. It indeed only requires testing on undiluted samples of natural waters or wastewaters discharged into the aquatic environment, except for wastewaters that demonstrate more than 50% effect. The scoring system ranks the waters or wastewaters in 5 classes of increasing hazard/toxicity, with calculation of a weight factor for the concerned hazard/toxicity class. The new classification system was applied during 2000 by the participating laboratories on samples of river water, groundwaters, drinking waters, mine waters, sediment pore waters, industrial effluents, soil leachates, and waste dump leachates and was found to be easy to apply and reliable. © 2003 Wiley Periodicals, Inc

THE CHARACTERISTICS OF THE HABITAT COMPONENT OF MUREȘ DEFILE

The Characteristics of the Habitat Component of Mureș Defile. The habitat component of Mureș Defile is almost entirely rural, consisting of 11 rural settlements grouped in three communes, and the village of Bistra Mureșului (Deda commune), and Vâgani, part of Toplița Town, which is actually a rural settlement. This analysis is mainly concentrated on the three communes (Stânceni, Lunca Bradului and Răstolița), starting with the setting up of a settlement hierarchy for the localities that make up the regional microsystem of Mureș Defile, represented by two systems (Toplița and Reghin), which in turn have their own subsystems (Stânceni and Lunca Bradului for Toplița, and Răstolița and Deda for Reghin), which enabled the identification of specific typologies for this area. In terms of the numerical evolution and housing dynamics of the area, of the last decades, there is a slight increase in the number of houses, which was not caused by population growth, but by the population needs and the increase in comfort requirements, as well as by higher incomes, in some situations, due to the migration of a relatively small population segment abroad, for work

THE HISTORY OF BORSEC MINERAL WATER BOTTLING

The History of Borsec Mineral Water Bottling. The mineral water springs of Borsec have been known to exist since ancient times. It started as a legend, presented by Orbán Balász, who mentions an author named Salzer. In his „Voyage Diaries in Transylvania”, Salzer recounts the discovery of healing springs in the area, and attributes it, like many other authors, to a Romanian shepherd called Gheorghe, who, suffering from ulcer, returning home one day, drank from one of the Borsec springs. Drinking the sour water, he felt better. Consequently, he remained there for a couple of days, drinking water from the same spot and curing his ailment. Written documents date back from the 16th century, when Bethlen Farkas, in the historical novel „Historia”, recounts that, in 1594, Sigismund Bathory, who resided in Alba Iulia, suffered from nervous exhaustion. His Italian doctor, Bucello, who knew about the curing effects of the Borsec mineral waters, prescribed a treatment using the water from the „Lobogó” spring. The water, transported to the princely estate in large covered barrels, eventually healed Sigismund Bathory. It is easy to see why, at the end of the 16th century, the mineral water of Borsec, with its miracle properties, was well known in Transylvania and at the imperial court of Vienna. The above mentioned spring, used from the 19th century onwards, for spas and for bottling, earned great renown, especially due to the high concentration of CO2 (over 2.5 g/l). The bottled sparkling water, due to its pleasant taste and its chemical stability, is the most sought after table water. This explains why, in most cases, the notion of mineral water is associated with „Borsec”

GEODEMOGRAPHIC CHARACTERISTICS OF MUREŞ DEFILE

Geodemographic Characteristics of Mureş Defile. This study begins with a short introduction regarding the exact limits of this area, which extends on a 38 km stretch between Vâgani (component of the Town of Topliţa) and Bistra Mureşului (component of Deda), in order to have a unitary perspective on this area, situated on the contact line between the volcanic massifs of Căliman (to the north) and Gurghiu (to the south). As required for every study concerning geodemographic characteristics, an analysis of the evolution of the number of inhabitants was presented, followed by complex issues on population quality (structure) (gender, age, habitat, proffesions, ethnic groups and religions), with interpretations, and graphical and cartographical representations for more than a century and a half (1850-2011). Alongside defining the concrete limits (east and west), the study brings another novel element, which is establishing the surface area for the entire area (26.17 km2), together with the four compartments (Vâgani-Ciobotani, Stânceni, Lunca Bradului and Răstoliţa), numbers which allowed for more thorough calculations, in terms of population territorial distribution

THE EXPLOITATION OF THE TULGHEŞ-GRINŢIEŞ URANIUM DEPOSIT. BETWEEN BENEFITS AND CONTROVERSY

The Exploitation of the Tulgheș-Grințieș Uranium Deposit. Between Benefits and Controversy. Romania is one of the few European states (alongside the Czech Republic, France, Germany, Ukraine) and one of the few in the world with uranium deposits (Canada, Australia, Niger, Namibia are others), mainly used in the energy sector. According to recent studies, the only currently exploited deposit (Crucea-Botușana, Suceava County) is nearly depleted (by 2019) and will be eventually shut down. For this reason, there are plans to open a new uranium mining facility in the Tulgheș-Grințieș area, where geological surveys have proven that the area holds the largest uranium deposit in the country. It will provide the necessary fuel for Cernavodă Nuclear Power Plant, for the two functional reactors, which have a total capacity of 706 MW each (producing roughly 18% of the country's electricity needs), as well as for units 3 and 4, not operational yet. The study at hand intends to emphasize several aspects regarding the exploitation possibilities for the uranium deposit from the two mineralized structures located in the fracture areas of the central Carpathian line, through which the crystalline overflows the Cretaceous Flysch. Furthermore, the environmental impact analysis as well as the long term safety and security of the population inhabiting the area will be of utmost importance