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Search Results: 1 - 10 of 161 matches for " Ecaterina Avram "
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Surface Properties and Compatibility with Blood of New Quaternized Polysulfones  [PDF]
Raluca Marinica Albu, Ecaterina Avram, Iuliana Stoica, Emil Ghiocel Ioanid, Dumitru Popovici, Silvia Ioan
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2011, DOI: 10.4236/jbnb.2011.22015
Abstract: The paper describes some properties of new quaternized polysulfones obtained by quaternization of chloromethylated polysulfone with different tertiary amines - N,N-dimethylethylamine and N,N-dimethyloctylamine. Hydrophilic/hydrophobic properties, morphological aspects and compatibility with red blood cells and platelets are affected by the alkyl radicals and by history of the formed films. The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion to the surfaces, or utilization of modified polysulfones as semipermeable membranes.
The Phytotoxic Effect of Some New Monoquaternary Salts of 4,4`-bipyridyl and 1,10-phenanthroline
Druta,C. Cuciac,Ramona Dana,Ecaterina Avram
Journal of Applied Sciences , 2002,
Abstract: Not Available
Geometric Aspects of Extremal Kerr Black Hole Entropy  [PDF]
Ecaterina Howard
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.43050

Extreme Black Holes is an important theoretical laboratory for exploring the nature of entropy. We suggest that this unusual nature of the extremal limit could explain the entropy of extremal Kerr black holes. The time-independence of the extremal black hole, the zero surface gravity, the zero entropy and the absence of a bifurcate Killing horizon are all related properties that define and reduce to one single unique feature of the extremal Kerr spacetime. We suggest the presence of a true geometric discontinuity as the underlying cause of a vanishing entropy.

SVD-MPE: An SVD-Based Vector Extrapolation Method of Polynomial Type  [PDF]
Avram Sidi
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.711111
Abstract: An important problem that arises in different areas of science and engineering is that of computing the limits of sequences of vectors , where , N being very large. Such sequences arise, for example, in the solution of systems of linear or nonlinear equations by fixed-point iterative methods, and are simply the required solutions. In most cases of interest, however, these sequences converge to their limits extremely slowly. One practical way to make the sequences converge more quickly is to apply to them vector extrapolation methods. Two types of methods exist in the literature: polynomial type methods and epsilon algorithms. In most applications, the polynomial type methods have proved to be superior convergence accelerators. Three polynomial type methods are known, and these are the minimal polynomial extrapolation (MPE), the reduced rank extrapolation (RRE), and the modified minimal polynomial extrapolation (MMPE). In this work, we develop yet another polynomial type method, which is based on the singular value decomposition, as well as the ideas that lead to MPE. We denote this new method by SVD-MPE. We also design a numerically stable algorithm for its implementation, whose computational cost and storage requirements are minimal. Finally, we illustrate the use of SVD-MPE with numerical examples.
An Architectural Solution of Assistance e-Services for Diabetes Diet
Vasile AVRAM,Diana AVRAM
Informatica Economica Journal , 2011,
Abstract: The aim of this paper is to outline the requirements and main architecture for a useful tool for determining the nutrition facts of food for people having Type 2 Diabetes. This diabetes is used only to establish the target audience, a “mass of people” having, maybe, to less in common regarding the computer usage skills. The characteristics of the target audience (huge number, diversity of habits and behaviors, computer usage skills) requires a solution based on web services delivered at least partly as a standalone/ portable application, build from Web services and provided with means for domain knowledge dissemination and usage.
Managing Knowledge within the Small and Midsized Companies
Vasile AVRAM,Diana AVRAM
Informatica Economica Journal , 2007,
Abstract: In the post decade the business environment was altered with direct impact to the way business organized and managed. The ability to capture and harness corporate knowledge has become critical for firms as they seek to adapt to changes in the business environment. Business rules management systems [BRMS] allows separating out the business logic and changing rules without impacting the remainder of the application, offering in that way a solution to faster adapt the informatic systems to changes. BRMS adds decision capabilities to application and workflow-type processes. Generally, small to midsized business budgets don’t allow for rip-and-replace approach and the software licensing can be prohibitive and restrictive too, leaving to that few options for complete information management. This paper introduces business rules, business rules management system together with a cheaper solution that can be used by almost small and midsized companies to manage their knowledge and support the decision making process.
Ecological niche of plant pathogens
Ecaterina Fodor
Annals of Forest Research , 2011,
Abstract: Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.
Letter to tefania Golopen ia (23.10.1958)
Revista Roman? de Sociologie , 2013,
The Institutionalization of Probation in Romania: Situational Practice and Strategies in the Context of the (Post-) Accession to the European Union
Revista Roman? de Sociologie , 2009,
Abstract: This study deals with the history of the institution of probation in Romania, its stages of development, its development strategies and practice, as well as the situational strategies specific to the crisis situations generated by the decision of aligning the activity of probation counselors to the relevant European rules In order to give consistency to our attempt, we focused on a crisis faced by the national probation system services, a moment triggered by the entry into force, as of April 1, 2007, of the amendments to Article 482 of the Criminal Procedure Code. The new provisions of Article 482 set out the obligation of criminal prosecution bodies (the police and prosecution offices) or of courts of law to request assessment reports in cases involving underage delinquents. The task of drafting these assessment reports is incumbent on the probation counselors in the 41 units existing at the national level. The study carried out within the Bucharest Probation Service tried to capture the practice and reactions of counselors in the context of the overloading of the Service's activity, the coping strategies for overcoming the crisis situation and the conclusion thereof.
Lamplighter Random Walks and Entropy-Sensitivity of Languages
Ecaterina Sava
Mathematics , 2010,
Abstract: The main purpose of this thesis is to study the interplay between geometric properties of infinite graphs and analytic and probabilistic objects such as transition operators, harmonic functions and random walks on these graphs. For a transient random walk, there are several problems one is interested in: for instance to study its convergence, to describe the bounded harmonic functions for the random walk, to describe its Poisson boundary, or to study the parameter of exponential decay of the transition probabilities of the random walk. In the first part of the thesis we deal with similar problems in the context of random walks on the so-called lamplighter graphs, which are wreath products of graphs. The convergence and the Poisson boundary of lamplighter random walks is studied for different underlying graphs, and the used methods are mostly of a geometrical nature. In the second part of the thesis we consider Markov chains on directed, labelled graphs. With such graphs we associate in a natural way a class of infinite languages (sets of labels of paths in the graph) and we study the growth sensitivity (or entropy sensitivity) of these languages using Markov chains.
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