Pressure in isochoric systems containing aqueous solutions at subzero Centigrade temperatures.

ObjectivePreservation of biological materials at subzero Centigrade temperatures, cryopreservation, is important for the field of tissue engineering and organ transplantation. Our group is studying the use of isochoric (constant volume) systems of aqueous solution for cryopreservation. Previous studies measured the pressure-temperature relations in aqueous isochoric systems in the temperature range from 0°C to - 20°C. The goal of this study is to expand the pressure-temperature measurement beyond the range reported in previous publications.Materials and methodsTo expand the pressure-temperature measurements beyond the previous range, we have developed a new isochoric device capable of withstanding liquid nitrogen temperatures and pressures of up to 413 MPa. The device is instrumented with a pressure transducer than can monitor and record the pressures in the isochoric chamber in real time. Measurements were made in a temperature range from - 5°C to liquid nitrogen temperatures for various solutions of pure water and Me2SO (a chemical additive used for protection of biological materials in a frozen state and for vitrification (glass formation) of biological matter). Undissolved gaseous are is carefully removed from the system.ResultsTemperature-pressure data from - 5°C to liquid nitrogen temperature for pure water and other solutions are presented in this study. Following are examples of some, temperature-pressure values, that were measured in an isochoric system containing pure water: (- 20°C, 187 MPa); (-25°C, 216 MPa); (- 30°C, 242.3 MPa); (-180°C, 124 MPa). The data is consistent with the literature, which reports that the pressure and temperature at the triple point, between ice I, ice III and water is, - 21.993°C and 209.9 MPa, respectively. It was surprising to find that the pressure in the isochoric system increases at temperatures below the triple point and remains high to liquid nitrogen temperatures. Measurements of pressure-temperature relations in solutions of pure water and Me2SO in different concentrations show that, for concentrations in which vitrification is predicted, no increase in pressure was measured during rapid cooling to liquid nitrogen temperatures. However, ice formation either during cooling or warming to and from liquid nitrogen temperatures produced an increase in pressure.ConclusionsThe data obtained in this study can be used to aid in the design of isochoric cryopreservation protocols. The results suggest that the pressure measurement is important in the design of "constant volume" systems and can provide a simple means to gain information on the occurrence of vitrification and devitrification during cryopreservation processes of aqueous solutions in an isochoric system

SUSTAINABLE DEVELOPMENT IN THE CONTEXT OF THE RELATIONSHIP ”MAN – NATURE”

In the long run, the environmental protection actions will have to correlate with the country’s social-economic development actions and the concept of durable development of the economy, resource exploitation and quality of the environment will have to be taken into account. It is common knowledge that the intensity of the pollution phenomenon is a result of the economic structure, especially of the industry, of the existing legal framework and of the level of ecologic education of the citizens in the country

Assessing the potential distribution of invasive alien species Amorpha fruticosa (Mill.) in the Mureş Floodplain Natural Park (Romania) using GIS and logistic regression

The assessment of invasive terrestrial plant species in the Romanian protected areas is an important research direction, especially since the adventive species have become biological hazards with significant impacts on biodiversity. Due to limited resources being available for the control of the invasive plants, the modelling of the spatial potential distribution is particularly useful in order to find the best measures to eliminate them or prevent their introduction and spread, as well as including them in the management plans of protected areas. Thus, the present paper aims to assess one of the most disturbing invasive terrestrial plant species in Europe – A. fruticosa in one of the most important natural protected area in Romania, i.e. Mureş Floodplain Natural Park (V IUCN category and RAMSAR –Wetlands of International Importance). The current study is a geographical approach seeking to explain the spatial relationships between this invasive species and several explanatory factors (soil type, depth to water, vegetation cover, forest fragmentation and distance to near waters, roads and settlements) and to assess its potential distribution by integrating GIS and logistic regression into spatial simulation. The resultant probability map can be used by the park’s administration in implementing the Management Plan in terms of identifying the areas with the highest occurrence potential of A. fruticosa according to the primary habitats and ecosystems and setting up actions for its eradication/limitation

Prototype isochoric preservation device for large organs

This paper presents the design and prototype of a constant volume (isochoric) vessel that can be used for the preservation of large organs in a supercooled state. This prototype is a preliminary version of a more advanced design. The device consists of a cooling bath operated by a mechanical vapor compression refrigeration unit and an isochoric chamber made of stainless steel. The preservation of organs using supercooling technology in an isochoric chamber requires a continuous temperature and pressure monitoring. While the device was initially designed for pig liver experiments, its innovative design and preservation capabilities suggest potential applications for preserving other organs as well. The isochoric reactor may be used to accommodate a variety of organ types, opening the door for further research into its multi-organ preservation capabilities. All the design details are presented in this study with the purpose of encouraging researchers in the field to build their own devices, and by this to improve the design. We chose to design the device for isochoric supercooling as the method of preservation to avoid the ice formation

Changes in ecosystem services from wetland loss and restoration: An ecosystem assessment of the Danube Delta (1960–2010)

Deltaic flood plains provide critically important ecosystem services, including food production, fresh water, flood control, nutrient cycling, spiritual values and opportunities for recreation. Despite growing recognition of their societal and ecological importance, deltaic flood plains are declining worldwide at alarming rates. Loss of wetland ecosystem services bears socio-environmental costs overlooked in land-use planning. Conversely, wetland restoration can deliver important long-term benefits. This paper examines effects of different land use policies on ecosystem services provided by the Danube Delta, one of Europe’s largest and most outstanding wetlands. First, we identify, characterize and measure the most important ecosystem services provided by the Danube Delta. Second, we assess trends between 1960 and 2010, contrasting periods of economic development (1960–1989) and ecological restoration (1990–2010). Our results indicate that i) the Danube Delta provides important services with benefits accrue from local communities to humanity at large, ii) that two thirds of the Delta’s ecosystem services have declined over the studied period and iii) that ongoing restoration efforts have so far been unable to reverse trends in ecosystem service decline. Benefits from ecological restoration policies are already becoming apparent, but at a scale not yet comparable to the costs from ecosystem decline incurred over previous decades. Ecosystem assessment Socio-environmental costs Wetlands Restoration Danube Delta RomaniaacceptedVersio

CENTRAL NUCLEAR ELECTRIC, A FUTURE OF ROMANIAN ENERGY

Official statistics show the year increasing the share of electricity produced in nuclear power plants. The most developed nuclear energy programs are: the United States, France, Japan, Germany and Canada. Although Romania was among the first countries in Eastern Europe that had a nuclear research program, switching to nuclear power reactors has been extremely difficult and slow. The implications of this decisionmaking process were the first political and then economic. There were a series of oscillations between Wer system offered by the USSR and the CANDU-PHWR supplied by Canada. Considering nuclear reactors Wer insufficiently protected against a nuclear accident, and the total requested by the former Soviet Union on the nuclear fuel cycle, the decision of us have opted for CANDU reactor, fueled with natural uranium, moderated and cooled with heavy water

Progress and Innovation through Evaluation Intellectual Property

Practical assessment of intellectual property is a complex and difficult issue because there are many factors that influence it, and apply the methodologies differ from one country to another, from one continent to another. Therefore, the responsibility of carrying out transactions these intangible assets is maximum, because they have social implications and / or political. Classical methods of assessment of intellectual property are the same as those used for measuring intangible assets or intangible.innovation, progress, valuation, intellectual property, intangible assets

THE INTERDEPENDENCE BETWEEN NEEDS OF RESOURCES, PRODUCTION STRUCTURES, AND SCIENTIFIC AND TECHNOLOGICAL INNOVATION PROCESS

At the intersection of three areas of high economic interest, Romania is a vital connecting point between the countries of Eastern Europe, Central Europe and Central Asia through the unique coexistence of a number of elements favorable. In this case, the economy must be understood as a means of achieving a human social purpose, whose growth must be of sociocentric and not economocentric. Hence the need to approach growth processes economical on much larger positions in going beyond the narrow meaning of the growth triangle - resources - environment with a wider perimeter of square economy - technology - social - ecology