Arhivă — Seria A

1

Monte Carlo investigation of light-ions fragmentation in water targets

J. Soltani - Nabipour, Maria Anca Popovici , Ligia Strasser,Gheorghe Cãta - Danil

The use of ion beams in cancer therapy requires accurate understanding of the complex processes of ion interaction with matter, as it is the production of secondary particles. During irradiation therapy, secondary neutrons, protons and heavier ions contribute to the prompt and delayed dose delivered to tumor and health…

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2

A study of the optical properties of quantum well solar cells aimed at optimizing their configuration

Paul Sterian, Silvian Fara, Laurentiu Fara, Mihai Iancu

This paper is based on the original contributions developed within the CEEX project Research regarding the efficiency increasing of nanostructured photovoltaic cells –NANO_PV (2006-2008) [1] regarding the influence of the optical parameters of the quantum well solar cells, upon conversion efficiency. It was considered …

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3

HYDROSTATIC PRESSURE AND TEMPERATURE EFFECTS ON THE DONOR BINDING ENERGY IN ASYMMETRICAL SQUARE QUANTUM WELLS

Nicoleta Eseanu, Ecaterina C. Niculescu

We calculated the effects of the hydrostatic pressure and temperature on the binding energy for centric shallow donors in asymmetrical GaAs/AlGaAs quantum wells, within the effective mass approximation and variational approach. We found that the pressure, temperature and asymmetry effects are mainly observed when the q…

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4

Pattern formation and selection in nanotube arrays

Ágnes e. Horváth, Ferenc Járai-Szabó, György Kaptay, Robert Vajtai, Zoltán Néda

Engineering practically interesting spatial patterns on nano- or micron scales is a top priority in modern material sciences. A convenient and relatively easy way to achieve this is through capillary self-organization. In the present work we study and model a nanotube array wetted by a liquid, which self-organizes duri…

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5

Live/dead cell assay based on dielectrophoresis-on-a-chip

Ciprian Iliescu, Guillaume Tresset, Florina S. Iliescu, Paul E. Sterian

The paper presents a field-flow separation method of particle populations in a dielectrophoretic (DEP) chip with asymmetric electrodes under continuous flow. The structure of the DEP device (with one thick electrode that defines the walls of the microfluidic channel and one thin electrode), as well as the fabrication a…

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6

Modeling with the chaos game (II). A criterion to define the relevant transition periods in ROMANIA

Eugen I. Scarlat, Constantin P. Cristescu, Cristina Stan, Mona Mihailescu

The paper is focusing on a new partition method of the transition époque suffered by the Romanian economic system in the last two decades as revealed by the Romanian Leu-United States Dollar exchange rate time series. By extending the results of a previous work, the method is considering the time evolution of the quart…

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7

Study of the solitons propagation through optical fibers

Dan Alexandru Iordache, Andrei Petrescu, Viorica Iordache

The specific features: a) non-linearity type, b) dispersive properties of the propagation medium, c) pulses coherence features, d) propagation equations, e) maintenance procedures, f) technical applications, etc. were studied both for some typical optical [e.g. the: (i) quadratic (QNLS), (ii) Kerr (cubic, CNLS), (iii) …

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8

Some results in aligning long range area of sensors

Romeo Ionicã

Silicon microstrip detectors represent principal detection elements of particle trajectories in many of particle physics experiments. In the last decade they are used in a very large scale. The main detection unit in the AMS tracker is the silicon sensor. A fast and precise mechanical alignment method of silicon sensor…

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9

Correlation of optical methods and measurements for investigation membrane changes of normal and malign tissues

Teodora ªtefãnescu, Ion Gruia, Iuliana-Maria Gruia, Cornelia Moþoc

The aim of this paper is to join together the opportunities of Mueller optical-coherent tomography for bio-tissues, named MOCT (Mueller optical coherent tomography), with the techniques for polarization, correlation and fractals of MMI (Mueller matrix images) for early diagnosis of cancerous and degenerative pathology …

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10

The evaluation of some parameters which characterize the Er -doped Ti:LiNbO optical waveguide couplers

Dragoº Dinu, Niculae N. Puºcaº

In this paper we report some experimental and theoretical results concerning the characterization of a directional coupler in Er :Ti:LiNbO optical waveguides. Based on the mode coupling theory we evaluated the coupling coefficient between two adjacent waveguides of the directional coupler.\r\nThe experimental IR trans…

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11

Optical communication methods based on chaotic laser signals

Paul Sterian, Valericã Ninulescu, Andreea Rodica Sterian, Bogdan Lazãr

Numerical investigations of two methods for the information transmission based on a chaotic deterministic carrier are performed. The first is represented by a ring optical cavity with a nonlinear medium inside, while the second refers to the synchronization of two laser diodes. These methods can be used for the transmi…

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12

Multi -variable prediction of physical data

Dan Stefanoiu, Janetta Culiþã

The paper aims to present a comparative study related to different approaches regarding prediction of multi-variable physical data. Data are provided by natural phenomena with geographical distribution (especially ecological and meteorological) and are stored as blocks of time series. Simulations have shown that the pr…

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13

Uncertainty estimation for SDAR-OES internal standard method

Ion Pencea, Catalin Eugen Sfat, Violeta Florina Anghelina

The spark discharge in argon optical emission spectrometry (SDARis theOES) is the most used technique for elemental analysis of metallic alloys due to its highest efficiency/cost ratio. In this field the SR EN 13005/2005 standard and other European documents as EA 4/16is the EA guidelines on the expression of uncertain…

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14

On a Peano - type axiomatication for free monoids

Alina Petrescu - Niþã, Ana Niþã

It is well-known the Peano axiomatization for the set of natural numbers. If X is a nonempty set and is the monoid of the words over X, can be characterized up to an isomorphism by an universality property and also by some internal properties. If hence a singleton, then is practically . In this paper, we giv…

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15

A note on proper affine symmetry in Bianchi types VIII and IX space-times

Ghulam Shabbir, M. Rafiq

We consider the most general form of Bianchi types VIII and IX space-times for studying proper affine symmetry by using holonomy and decomposability, the rank of the Riemann matrix and direct integration techniques. While studying proper affine symmetry in the above space-times it is shown that there exists only one …

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16

Credibility formulas allowing effects like inflation

Virginia Atanasiu

In this article we will obtain, just like in the case of classical credibility model, a credibility solution in the form of a linear combination of the individual estimate (based on the data of a particular state) and the collective estimate (based on aggregate USA data).

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17

Application of Green’s functions in analysis of the response of an infinite homogenous structure to moving load

Traian Mazilu

The aim of this paper is to present a numerical method based on the Green’s functions to calculate the response of an infinite homogenous structure to moving load. The structure has two beams continuously supported by elastic layers and represents the common model of the slab track. The high accuracy of the method is p…

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18

Nonholonomic geometry of Gibbs contact metric structure

Cristina Stamin, Constantin Udriºte

The paper connects the Vrânceanu congruence theory with our theory of odd-dimensional nonholonomic thermodynamic systems. To build the Riemannian metric, the authors use certain congruences with thermodynamical meaning. Based on this metric, the differential invariants of the Gibbs- Vrânceanu-Riemann nonholonomic space…

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19

On Udriºte ode and a problem of Jiang

Gabriel Bercu, Claudiu Corcodel, Mihai Postolache

In our paper [1], we introduced a new class of self-concordant functions, defined on Riemannian manifolds endowed with metrics of diagonal type. The aim of this note is twofold. First we introduce a class of self-concordant functions which generate the given metric. Then we give positive answer to an open problem by Pr…

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20

Some new types of vertical 2-jets on the tangent bundle of a Finsler manifold

Adelina Manea

We provide a basis of the vertical bundle of a Finsler manifold, adapted to the Liouville foliation FL’. We define the vertical 2-jet bundle Jv,2(TM0) and the leafwise, transversal and mixed vertical 2-jet bundles with respect to FL’. The main result is the existence of a diffeomorphism between the total space Jv,2(…

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21

-semihypergroups and their properties

D. Heidari, S. O. Dehkordi, B. Davvaz

Algebraic hyperstructures are a suitable generalization of classical algebraic structures. In a classical algebraic structure, the composition of two elements is an element, while in an algebraic hyperstructure, the composition of two elements is a set. The concept of -semihypergroups is a generalization of semigroups…

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