Browse

The paper presents an exergy analysis of a heat pump with a steam injection. Different refrigerants as R290, R152A and R1234yf are considered. Constructive schemes such as two-stage heat pumps or cascade couplings are known and used to reduce the temperature at the compressor discharge level, but the presence of two or more compressors increases the cost of the initial investment of the equipment. This paper presents the design of a steam injection heat pump that has the advantage of a simple construction and can ...

Cryogenic energy storage (CES) is a large-scale energy storage technology that stores electricity in the form of liquefied gas at cryogenic temperatures. The CES system has three sub-processes, namely, charging or liquefaction, storage, discharging or power cycle. Because the main energy costs in this system are related to the liquefaction module, we will focus on the analysis of liquefaction processes. The present work aims at performing a comparative study between cycles commonly used for the liquefaction of air...

The paper presents well-preserved microfaunas (foraminifers and ostracods) enclosed in cuttings samples and cores recovered by 6 hydrocarbon wells drilled in the Moesian Platform, in Silistea area, S Romania. The lithological and micropaleontological obtained data improve the stratigraphic knowledge at regional level. The analyzed samples contain foraminifera that characterize biozones extending in the Sarmatian, as follows: the middle Volhynian Varidentella reussi, the late Volhynian Elphidium reginum, the early ...

The possibility of regeneration of plants from somatic and genetic cells open the way of in vitro storage of the genotypes. The utilisation of such a method has a lot of advantages as: relatively reduced space for preservation of a large number of multiplicated clonal plants, the plants are preserved free of pathogens and viruses, in special storage conditions, the plants don?t need special treatments during preservation, the material has an adequate form for establishing nuclear stocks which make possible rapid p...

The possibility of regeneration of plants from somatic and genetic cells open the way of in vitro storage of the genotypes. The utilisation of such a method has a lot of advantages as: relatively reduced space for preservation of a large number of multiplicated clonal plants, the plants are preserved free of pathogens and viruses, in special storage conditions, the plants don?t need special treatments during preservation, the material has an adequate form for establishing nuclear stocks which make possible rapid p...

The groundwater quality survey can be made by using monitoring and analysis tools that are able to manipulate time-series large datasets showing a spatial reference. Data correlation with the spatial distribution of the hydrogeological structures is compulsory. Within the urban environment the problem show a larger complexity because of the infrastructure interaction. Within the collaboration framework between several Spanish and Romanian institutions a management, analysis, and modeling hydrogeological platform f...

The detailed modeling of sedimentary media (alluvial sediments, deltas, etc.) that form important aquifers is very complex for two reasons. The first is the intrinsic natural heterogeneity of the geological medium and the second is that the data management tools (manipulating geological and hydrogeological data) needed to implement them in the hydrogeological models are not developed enough. The paper presents a software platform containing methodologies and tools that facilitate the integration of the 3D geologic...