AbstractThe present work carries out a parallel analysis between the performances and, on the other hand, of the restrictions of two different model systems designed to assess the nearshore circulation. These are SHORECIRC, which is a widely known general prediction system for nearshore circulation and ISSM (the Interface for SWAN and SURF Models). SHORECIRC is a quasi-3D model that combines a numerical solution for the depth-integrated 2D horizontal momentum balance equations with an analytical...
Autori: Eugen Rusu, Silviu Macuţă
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25345

Abstract Analytical equations for the variation of soil moisture content and for the local storage coefficient for a layered soil with a relatively shallow water table were developed in this study, based on a linear distribution law of the moisture retention on soil's profile, and the van Genuchten-Mualem parametrical model for the moisture-suction curve. By considering this mathematical model, an original computer code was written in MATLAB to determine and then to graphically represent the...
Autori: Dan Prepelita, Stefan Popescu, Esmeralda Chiorescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25429

Abstract:The paper presents the virtual prototype of a robotic system for spray pyrolysis deposition (SPD). To design of the mechanicaldevice model of the robotic system, the MBS environment ADAMS of MSC Software was used, while the MATLAB/Simulink ofMathworks was used for the dynamic analysis of the robotic system, according to the mechatronic concept. A control loop waschosen, composed by a multi-body mechanical model, connected to the dynamic model of each motor. The main objective is toverif...
Autori: Cătălin Alexandru, Monica Enescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25744

Abstract:The paper presents a method to improve the efficiency of a photovoltaic (PV) string by employing a mono-axis trackingmechanism. The tracking system was optimized so that it has minimum energy consumption during tracking. The PV stringsimultaneously changes the daily position using a linear actuator which transmits the motion to all modules by a rack-pinion gearmechanism. The system is designed in virtual prototyping concept with the following software solutions: for the solid modeling -...
Autori: Cătălin Alexandru, Nicoleta-Irina Tatu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25766

This paper presents a mathematical model for the prediction of pollutant transport in rivers. The model has been developed and calibrated using the Matlab software and relying on field data from Romanian Someş River (collected in case of accidental cyanide release). Field data has been used to estimate model parameters (e.g. dispersion coefficient, velocity) as variable in time and space in order account for river features non-uniformity in time and also in space. These initial parameter va...
Autori: Elisabeta-Cristina Ani, Vasile Mircea Cristea, Paul Serban Agachi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25848

AbstractWastewater streams and particularly industrial effluents tend to increase in volumes and to get more complex in terms ofpollution. Nevertheless, nowadays the focus is directed towards recycling or reuse of treated wastewater so as to close the wateruse loop. Advanced wastewater treatment allows these possible applications by achieving good quality effluent to suit the newpurposes, but the implementation of this treatment stage is a difficult task. This study gives an example on how to ap...
Autori: , Daniela Cailean, Florina Ungureanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25971

AbstractThis study is focused on simulating and optimizing design and configuration of anaerobic baffled reactor (ABR) by means ofartificial neural network (ANN). This approach is aimed to assess an efficient ABR performance in various operational conditionstreating municipal wastewater. For this purpose, to analyze comprehensively on a base of experimental data, the system isoperated in two pilots of 48 liters net volume made of 8 compartments. In 7 months, more than 130 sets of data are obtain...
Autori: Gagik Badalians Gholikandi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26260

AbstractBased on principles of feeding solid waste into vertical boreholes in fully mechanized coal mining and backfilling technology,the literature established a trajectory model of particles in gas-solid two-phase flow for the sake of reducing the damage tostorage silo underground done by enormous impulsive force generated by falling solid waste. In addition, dynamical analysismethod in gas-solid two-phase flow field was adopted herein to study the solid particles’ force characteristics and th...
Autori: Nan Zhou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26271

AbstractThe paper presents the structure of an active parallel filter for reducing harmonic pollution and reactive power. The active powerfilter control is based on instantaneous reactive power theory. The control is made in the system of axes  - , which use directand inverse transformation to obtain the equations from one system to another coordinate axes. The authors present the modelingof parallel active filter based on this theory and the simulation results in MATLAB-SIMULINK...
Autori: Marius Marcu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26397

AbstractThe distribution of mixing time for a split-cylinder gas-lift bioreactor has been investigated for simulated broths with apparentviscosities up to 26 cP. The results indicated important variation of mixing time on the height of riser or downcomer, as well asdifferent behavior of dispersion flows in the two regions. Thus, the highest mixing efficiency for the ascending circulation hasbeen recorded for the intermediary positions, placed above the sparger. Contrary, for the downcomer, the i...
Autori: Anca-Irina Galaction
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26560

Abstract The deterioration of the natural polymers is a very complex process, and a problem that can be best addressed through modelling. The approach for modelling the rheological behaviour of different cellulose-based textile fibres (cotton, hemp, flax) when subjected to a hydrothermal treatment, followed by exposure to different doses of gamma-rays (5, 10, 15 and 25 kGy) is presented here. In order to predict the optimum radiation dose limit and hydrothermal aging time, the mathematical m...
Autori: Angelica Olaru
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26678

Abstract In this paper, the structure and working principles of a microbial fuel cell (MFC) are analysed, and a mathematical simulation model of MFCs is established based on the electrochemical equation, kinetic equation and material balance equation of a MFC. A simulation analysis and discussions are conducted in a MATLAB environment to investigate the effect of acetate concentration, influent flow and external resistance on the performance of a MFC system. The simulation model is demonstra...
Autori: Aimin An
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26803

There are many models developed for the adjustment of the 2D or 2D+1D geodetic networks, both on the ellipsoid surface and in the map projection plane. These models are widely used by practitioners. In this paper we presented two new mathematical models for the adjustment of combined geodetic measurements and networks (those collected using Global Navigation Satellite System (GNSS) technology plus earlier terrestrial methods). Such combined networks can be adjusted either in a Cartesian geoc...
Autori: Andrei-Șerban Ilie
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27051

The goal of this paper is to determine the characteristics of a Stirling engine able to be used by a micro-solar power plant as energy conversion system. The purpose is to use solar energy as heat source and a Stirling engine because of its numerous advantages, as its high (theoretical) efficiency. This work was made in collaboration with several industrials involved in the project named MiCST, whom objective is to electrify remote villages in Africa. Results of a simple 0-D model built on M...
Autori: Nadia Martaj
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27116

This paper presents an advanced numerical algorithm for the optimization of the current density distribution in electrochemical applications. The optimization principle consists in the distortion of the electric field by an insulating shield properly positioned between the electrodes. Such a distortion influences the distribution of current density at the electrodes under consideration. The electrochemical problem is approached by a Laplace equation which is numerically solved using a mesh-free ...
Autori: Alexandru Avram
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27199

Availability of alternate fuels for cogeneration helps to limit the amount of bagasse as fuel at sugar plants and make them available for other uses such as paper manufacture or ethanol production. Due to the increased awareness on the adverse effects of carbon dioxide emission on the environment, power plant operators are compelled to reduce emissions of pollutants during cogeneration. Selection of low pollutant fuels, tapping of renewable energy and use of efficient operating policies can help...
Autori: Faisal Pazheri
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27244

Floods have long been the cause of severe human and economic loss. Structural measures are applied to minimize the consequences of these natural disasters. A potential mitigating approach is the design and implementation of a control strategy for the water network aimed to regulate the water flowing within the river catchment system. There are several tools that have the ability to model and forecast the flood events in water networks. However, some tools are limited in the ability of providing ...
Autori: Phạm Thai Hňa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27278

The propagation of electromagnetic radiation was investigated at different points, and the theory of covariance was applied to identify the main parameters by recording the max, mean and min values of density. The biggest electric field strength values are emitted by the second generation (2G) GSM mobile phones that operate in the frequency band of 900 MHz. The smaller electric field strength values are determined by the higher frequency (1800 MHz) used by mobile phones and smaller maximum power...
Autori: Raimondas Buckus
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27314

In this paper, a model based on Back-Propagation (BP) artificial neural network was proposed, as a tool predict the soil suitability for cultivation in Jiangxia district. The model takes the soil nutrients indicators as the input and the level of soil suitability as the output. The correlation analysis showed that the correlation coefficient between expected output and actual training result is 0.99. The simulative results indicate that the learning and generalization ability of the model perfor...
Autori: Zhuoyan Feng
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27546

Optimal evacuation routes are crucial to protect workers’ safety when accidental leakage of toxic gas occurs in chemical plants. However, the majority of route optimization focuses on the transport field and few on the evacuation routing optimization in chemical plants. This paper proposes a dynamic evacuation routing optimization method for chemical plants under toxic gas release scenarios. From the complete accident scenario set (CASS) built with wind fields and leakage sources, the leak...
Autori: Ying Liu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28336