AbstractBased on the simulation equations, which were developed earlier (Rao, 1999 and Rao et al., 2007) relating the oxygen transfer coefficient k (= KLa20 (?ľ/g2)1/3) with theoretical power per unit volume of water X (= N3D2/g4/3?ľ1/3) and k with actual powerconsumed by the surface aerators per unit volume PV (= P/(V??(g?ľ)1/3), methodology has been demonstrated to the save the energy consumption, defined by ?? (=PV /k), where KLa20 is the overall oxygen transfer coefficient at 20oC, ?ľ is kin...
Autori: Achanta Ramakrishna Rao, Bimlesh Kumar, Neelam Verma
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25243

AbstractThe effective mass transfer area of a Mellapak 750 Y structured packing was measured in a bench-scale plant with a column having an internal diameter of 100mm, and a packing height of 518 mm, using a broad range of gas and liquid flow rates. The absorption of carbon dioxide into natrium hydroxide aqueous solutions of 0.5 and 1.0 mol/L has been employed as test reaction. The validity of data obtained was tested by checking the two conditions of fast pseudo first order irreversible reactio...
Autori: Anton Friedl, Ilie Siminiceanu, Michael Harasek, Mihaela Dragan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25264

AbstractThe study on distribution of oxygen transfer rate for a stirred bioreactor and simulated broths was carried out for four positions inside the broth and indicated the significant variation of kla on the bioreactor height. For all considered positions, kla initially increased to a maximum value with mixing intensification, decreasing then, as the result of the modification of mixing mechanism in presence of air bubbles. The increase of broth viscosity led to the significantly reducing of o...
Autori: Adina Segneanu, Anca-Irina Galaction, Dan Caşcaval, Radu Z. Tudose
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25270

AbstractTheoretical and experimental studies of gas drying processes by adsorption in fixed bed of grains are presented in this paper. Based on an extensive literature study, some of the most representative mathematical models describing gas adsorption in fixed bed and consequently gas drying processes by adsorption in fixed bed are also presented. Using a mathematical model from those mentioned describing adsorption under isotherm regime, the temperature and gas flow velocity effects over the d...
Autori: Marius Sebastian Secula, Stelian Petrescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25272

AbstractIn the theory of relations between economical branches, a variety of balance of connections between the branches (BLR) models is used, whose theoretical construction is based on a series of hypotheses according to the purpose of each model. In this paper models which make use of the natural units are applied in the analysis of fluxes between industrial branches. ...
Autori: Aurel Burciu, Ionel Bostan, Petru P. Condrea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25277

Abstract In this paper preliminary results of studies concerning the extraction of uranium(VI) from soils in aqueous PEG (1550) 20 % - Na2SO4 20 % - Na2CO3 10-2-10-3 M two-phase systems are presented, as well as the spectrophotometric determination of extracted uranium with pirocatechol violet (PV). A special attention was given to the experimental factors (pH, redox potential, CO32- anion concentration and initial uranium concentration), which was found to influence both the formation and stabi...
Autori: Daniel Condorachi, Doru Juravle, Dumitru Bulgariu, Laura Bulgariu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25290

Include urmatoarele articole:� Removal of nickel from aqueous solution by Nordmann FIR (ABIES Nordmanniana (STEV.) SPACH SUBSP. Nordmanniana) cones� Determination of heavy metals in extracts and macerates from garden flowers� Biological phosphorus removal in a high performance single reactor � Advanced Cd2+ removal on dispersed TioO2-fly ash � Remediation techniques for contaminated soils� Separation of uranium(vi) from soils by extraction in aqueous PEG (1550) - Na2SO4 - Na2CO3 two-...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25296

AbstractThe sorption of Pb(II) and Hg(II) ions from aqueous solutions by moss peat (from Poiana Stampei, Romania) was studied in a batch system. The data obtained from experiments of a single-component sorption were analyzed using Langmuir and Freundlich models. The Langmuir equation describe sorption isotherm of Pb(II) and Hg(II) with high correlation coefficients, and better than Freundlich model. According to the Langmuir model, the maximum uptake capacities of moss peat for Pb(II) and Hg(II)...
Autori: Dumitru Bulgariu, Laura Bulgariu, Matei Macoveanu, Mioara Răţoi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25311

AbstractThe paper defines the average and local soil storage coefficients, for a soil with relatively shallow water table. By means of an adequate law for the suction distribution on soils level and certain parametrical models for the moisture retention curve of soil, the analytical equations for these storage coefficients were determined. Theoretical results are to be applied for a case study and on the basis of a pertinent analysis, and some recommendations were made for the practical use of f...
Autori: Daniel Toma, Esmeralda Chiorescu, Stefan Popescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25319

Include urmatoarele articole:� Composite membranes with cross-linked matrimid selective layer for gas separation� Determination of organic compounds from different types of coffee by Hplc and Gc-Ecd analysis� An integrated assessment of the suitability of domestic solar still as a viable safe water technology for India� Investigations on the possibility of natural hemp fibers use for Zn(II) ions removal from wastewaters� Removal of acid red 398 dye from aqueous solutions by coagulation...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25340

AbstractThe study on the distribution of oxygen transfer rate in a stirred bioreactor for Propionibacterium shermanii broths underlined the major influence of the presence and concentration of biomass on the interphasic transfer of oxygen. Owing to the bubbles surface blockage by the bacterial cells, the accumulation of biomass from 30.5 to 120.5 g/l d.w. led to the decreasing of kla for about 1.3- 2.4 times. Compared with the simulated broths without biomass having similar apparent viscosity, t...
Autori: Adina Segneanu, Anca-Irina Galaction, Dan Caşcaval
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25364

â€? Bioremediation of contaminated air using a bioscrubberâ€? Quality risk evaluation of the groundwater resources on the moldavian areaâ€? Electrochemical characterization of some dental materials in accelerated environmental testingâ€? Preliminary study of simple and Fenton oxidation with hydrogen peroxide applied on final effluents from a zootechnical farmâ€? The environmental impact assessment caused by the dykes failureâ€? Revaluation of beer industry byproducts – medical implicationsâ€? ...
Autori: http://www.ecozone.ro/reviste.php?RID=25372

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 In designing an efficient photovoltaic system, the meteorological data of the system location must be considered. Field data registered over years prove the importance of the implementation site characteristics in the design and optimal exploitation of a PV system, because wetting and atmospheric gaseous and particulate pollution can strongly distort the incident solar radiation. Thus, in addition to the efficiency of the solar module, the tracking efficiency, the clouds crossing fac...
Autori: Dorin Valentin Diaconescu, , Ioana Sinziana Hermenean, Maria Monica Vatasescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25464

Abstract Increasing the solar energy conversion into electrical or thermal energy represents an European and national priority, because it offers clean alternatives to the use of fossil fuels, in no pollutant systems, based on photovoltaic modules and solar collectors. The global solar radiation is the most important factor affecting the amount of energy produced by a PV module. In direct connection with the change in the solar energy conversion, the TR - Loss Coefficient (Tr??bungsfaktor) is...
Autori: , Dorin Valentin Diaconescu, Maria Valentina Dinicu (Popa), Bogdan Gabriel Burduhos
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25465

Abstract Phenols and chlorophenols are contaminants in soils, sediments, surface waters and groundwater, largely because of their worldwide utilization in the last 50 years as wood preservatives and general biocides in industry and agriculture. The toxicity of chlorophenols and their persistence in the environment require advanced treatment techniques for their removal. This study presents the results of a comparative evaluation of the adsorption of phenol and 4-chlorophenol from aqueous sol...
Autori: , Cezar Catrinescu, Roxana Elena Apreutesei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25497

Abstract The paper presents the experimental results, obtained using a pilot installation and hot-water boilers for reducing the pollutants emissions in combustion of heavy liquid fuels by using of additives for catalyzing of burning processes. The experiments were made using additives based on iron and cerium carboxylates. Experimental results, which are presented both in variant of heavy liquid fuels burning with additives and without additives, highlight the reducing of pollutants emissio...
Autori: Aurel Gaba, Stefania Iordache, Mircea Vladescu, Dan Ungureanu, Petrica Vizureanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25509

Abstract The goal of the study was to investigate the sorption behavior of Acid Orange 7 (C.I. 15510) onto soil collected from Iasi area (Romania). The sorption isotherm, kinetic and thermodynamic studies were performed by batch mode. The effects of experimental parameters such as contact time, pH value (2-12) and temperature (20 - 400C) have been studied. Also the influence of initial dye concentration (10 - 100 mg/L) and sorbent dosage (from 5 g L-1 to 150 g L-1) were studied. It was found ...
Autori: Camelia Smaranda, Dumitru Bulgariu, Maria Gavrilescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25566

Abstract The use of biomaterials as biosorbents for treatment of wastewaters will provide as a potential alternate to the conventional treatment methods. The main advantages of biosorption are high selectivity , cost effectiveness and good removal performance. World wide numerous low cost bio materials have tried for biosorption of dyes. In this present investigation, the dead biomass of Penicillium sp. fungus and wood sawdust was used as biosorbents and their capacity to removed malachite gr...
Autori: Cornel Pohontu, Florin Luca, Igor Creţescu, Manea Liliana, Mariana Diaconu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25593

Abstract A five-year survey of gross ?ŽÂą+?ŽÂ?, 226Ra, and 137Cs in soils and selected spontaneous plants (Hypnum cupressiforme, Urtica dioica, Dryopsteris filix-mas, and Cirsium arvense) in the Crucea and Lesu Ursului mining areas is presented. The maximum activities in soils were fond to not exceed 0.257 Bq/g for gross ?ŽÂą+?ŽÂ?, 0.35 Bq/g 226Ra, and 0.05 Bq/g 137Cs. All plant species shown similar capabilities for gross ?ŽÂą+?ŽÂ? and 226Ra accumulation. The soil-to-plant transfer coeffi...
Autori: Alexandru Cecal, Catalin C. Nica, Dan T. Costin, Danut G. Cozma, Karin Popa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25604

Abstract Unlike the P. shermanii and S. cerevisiae cultures, the study on the distribution of oxygen transfer in stirred bioreactor for P. chrysogenum free mycelia broths indicated that this process is controlled mainly by the high apparent viscosity of broths, and less by the presence of fungus biomass. For this reason, the influence of fungus accumulation on the reduction of kla is attenuated compared with that obtained for bacterial or yeasts broths. The lower influence of fungus biomass i...
Autori: Anca-Irina Galaction, Dan Caşcaval, Marius Turnea, Stefanica Camarut
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25606

Abstract Characterization of soil permeability is of great importance for several geotechnical analyses. In common practice, because of the difficulty in sampling of granular material, constant head permeability tests are usually employed on specimens having similar relative densities to those in the field. An alternative approach to permeability tests for granular soils is the prediction of permeability levels by means of empirical equations depending on several particle size distribution an...
Autori: Alper Sezer, Burak A. Goktepe, Selim Altun
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25609

Abstract Artificial neural networks (ANNs) are capable of learning the relationships between the dependent and predictor surface water quality variables and have a high ability to predict from the new data set. In this study, two different ANN methods, the feedforward network (FFN) and the cascadeforward network (CFN) were applied to predict two surface water quality variables such as chlorophyll-a (Chl-a) and fecal coliform (FC) using twelve other variables as an input to the models. Both me...
Autori: Hasan Merdun, Ozer Cinar
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25623

Abstract Mathematical modeling of the ultrafiltration (UF) process is motivated by the complexity of retention phenomena that occur during the UF in conjunction with the complexity of wastewater matrices submitted to ultrafiltration, as well as by the need to predict the process behavior in extreme conditions, such as high pollution loads for UF-membrane cleaning cycles optimization or for automated control of the process. Thus, series of laboratory-scale ultrafiltration experiments were perf...
Autori: , George Barjoveanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25630

Abstract:The operation of solar air heat collectors consists in a sequence of transient regimes, being conditioned by the availability in timeof the solar resource. This paper presents the results of an experimental research on transient regimes of two types of solar air heatcollectors. The absorbers of the collectors have different configurations and are made of different materials. One collector is acommercial passage air collector with the absorber made of aluminum. The other collector is an ...
Autori: Adrian Ciocănea, Andrei Dragomirescu, Sanda Budea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25731

Abstract:This paper aims to analyze two types of wooden briquettes made from different raw material, in order to determine thecompactness of the wood used, namely their compaction coefficient. This factor is a new feature of briquettes that defines moreprecisely the quality of them. The density of raw material and briquettes causes the compaction coefficient, namely the ratiobetween them. Relevance of research and scientific innovation results from the fact that European standard of wooden briqu...
Autori: Aurel Lunguleasa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25753

Abstract:The aim of this work is to obtain sintered porous membranes with graded structure for microfiltration by sedimentation andsintering of metallic powders. Our previous studies have demonstrated the possibility of obtaining sintered porous materials withgraded structure by sedimentation. In this paper, spherical nickel particles were used having a grain size in the 2-90 Âľm rangemeasured by the laser scattering particle size analyzer. The powders were sedimented into a sintering die in a s...
Autori: Gyorgy Thalmaier, Ioan Vida-Simiti, Nicolaie Jumate, Niculina Sechel, Valentin Moldovan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25775

Abnstract:In recent years, solar receivers have been employed in several applications where high temperature fluids are involved, such aspower plants and solar thermal reactor. The possible presence of high temperature gradients could determine reduced receiverefficiency and a short life of the material. Thermal and fluid dynamic analysis of the receiver allows to highlight possible presenceof temperature gradients and to evaluate their values and the more critical zone of the material. Compress...
Autori: Alina Adriana Minea, Oronzio Manca, Salvatore Tamburrino, Sergio Nardini
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25779

Abstract:In this paper, the mathematical model is improved by considering the density variations of the liquid from the pollution source vs.pollutant’s concentration of this liquid and by including the sorption-desorption term (SDT), which takes into account thisphysical process, played by a first-order decay model defined by two coefficients and an exponent. In order to practically use thisimproved mathematical model, the authors inferred the calculating relationships from automatic processin...
Autori: Daniel Bucur, Esmeralda Chiorescu, Gheorghe Ţigaret
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25783

Abstract:In this study, the adsorption mechanism of a reactive azo dye, Reactive Yellow 125 (RY 125), onto a nitrogen doped TiO2 modified zeolite (Z-TiO2-N) has been examined in order to identify the affinity of the material for the investigated pollutant envisaging its degradation by heterogeneous photocatalysis. Equilibrium experiments were performed and the data obtained were fitted with different isotherm equations, i.e., Langmuir, Freundlich, and Dubinin-Radushkevich (D-R). The Freundlich i...
Autori: Cornelia Ratiu, Elida Cristina Ilinoiu, Florica Manea, Laura Cocheci, Liliana Andreea Colar, Rodica Pode
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25809

This paper refers to the post-Darcy free level uniform filtration. The capillary tube fascicle model is applied to this filtration. The theoretical Ch?Šzy coefficient is computed and also experimentally verified for a homogenous and isotropic material, made of glass spheres. The typical features for the free-level post-Darcy filtration (depending on slope) are the lover, critical and higher stages flows....
Autori: Aron Gabor Molnar, Daniel Toacă, Daniel Toma, Iosif Bartha, Nicolae Marcoie, Victor Gabor
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25833

The reactive extractions of propionic acid with TOA dissolved in three solvents with different dielectric constants (dichloromethane, butyl acetate, n-heptane) without and with 1-octanol as phase modifier have been comparatively analyzed. The results indicated that the mechanism of the interfacial reaction between acid and extractant is controlled by the organic phase polarity. In absence of 1-octanol, the structures of the extracted complexes are RCOOH.Q2 for dichloromethane and butyl acetate, ...
Autori: Alexandra Cârlescu, Anca-Irina Galaction, Dan Caşcaval, Mădălina Poştaru
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25938

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

Equilibrium and kinetics of nitrate removal from aqueous solutions of pH = 6.8 were investigated using the strong base anion exchange resin (Purolite A-520E) in the batch method. The experimental equilibrium data were analyzed by means of the Langmuir, Freundlich and Dubinin-Radushkevich sorption isotherm models. The Langmuir model describes sorption isotherm of nitrates with high correlation coefficients and better than Dubinin-Radushkevich and Freundlich models. The effect of temperature on th...
Autori: Anca Ceica, Igor Creţescu, Ion Balasanian, Laura Bulgariu, Liliana Lazăr
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25851

AbstractThe transport of gases and solvents in polymeric membranes is an important phenomenon with many technical applications, suchas the mixture separation using polymeric membranes, the polymeric membrane preparation, the polymer devolatilization and theselection of appropriate polymeric membranes for a certain process. In most membrane separation operations and manufacturing,equilibrium and diffusion data are required.Useful information on equilibrium and diffusion can be obtained from the s...
Autori: Ciprian Constantin Negoescu, Eugenia Teodora Iacob Tudose, Ioan Mămăligă, Nicoleta Bunduc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25975

AbstractFlood inundation modelling and flood risk mapping are primary cornerstones of flood risk assessment and management.Modelling activities generally assume that the morphology of the conveyance does not change, which certainly is not true foralluvial rivers. River bed elevations can quickly change during flood events. Flood water can induce different bed-forms (ripples,dunes, plain bed, etc.), which affects the flow resistance and as a result the flood water level. As a result integrating t...
Autori: Biswa Bhattacharya, Ioana Popescu, MdShamim Shams
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26016

AbstractThe HR BREACH model is a physically based numerical model for the simulation of breach initiation and formation throughembankment dams, dykes, and flood embankments. The model is used for the analysis of homogenous as well ascomposite/zoned embankments. Simulation can also include the effect of surface protection such as grass or rock blocks. Twobreach failure modes are available: failure by overtopping and failure by piping. Breach growth can proceed through surfaceerosion or head-cut e...
Autori: Andreja Jonoski, Ioana Popescu, Mark Morris, Mohamed Hassan, Tseganeh Gichamo
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26017

AbstractThere are many treatment methods used to remove color from textile wastewater, and Fenton oxidation, a well known AdvancedOxidation Process is one of the most efficient. Apart of Fe(II), other metal ions have been used as catalysts in Fenton’s Reagent,and Cu(II) proved to be a good alternative.In this study the effect of the concentration of dye, catalyst and hydrogen peroxide were studied and optimized for thediscoloration process of Reactive Black 5 using a Fenton-like process, H2O2/Cu...
Autori: Andrei-Petru Bertea, Armand-Florin Bertea, Romen Butnaru
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26042

AbstractIn recent years non-metric digital cameras have known a great development, being used in wide applications, such as: real timemonitoring and preservation of cultural heritage, the shoreline dynamics study, the wave movement for costal protection, soilerosion, etc. Clasic photogrammetry with the use of metric cameras are still of great use in areas such as architecture andenvironmental imaging. An old problem occurs when we want to extract metric information from our environment using clo...
Autori: Ersilia Oniga, Maximilian Diac
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26061

AbstractThe design of hydrotechnical constructions requires knowing certain hydrological quantities necessary for their dimensioning.The annual average turbidity is one of these quantities. The issue is that, in some river sections direct observations andmeasurements do not exist regarding this hydrological quantity, so that different empirical relationships developed by variousauthors based on long observations and measurements are applied, such as that developed by Poliakov. Turbidity depends ...
Autori: Ilinca Dinu, , Tomi-Alexăndrel Hrăniciuc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26066

AbstractWith the development of transportation systems, the associated traffic noise problem has drawn more and more attention in HongKong. Under the Hong Kong Planning Standards and Guidelines, a standard of 70 dB(A), measured as LA10 (1 hour), has been setfor road traffic noise. The Calculation of Road Traffic Noise (CRTN) method has been adopted in Hong Kong to estimate suchnoise. This study first examined and evaluated the accuracy of this method in predicting traffic noise at different floo...
Autori: Cheuk Ming Mak
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26082

AbstractExperiments were designed to optimize the Cr(VI) adsorption on Salvinia cucullata. The significance of different adsorptionparameters along with their combined effect on the adsorption process has been established. A regression equation wasformulated by representing percentage of Cr(VI) adsorption as a function of different independent variables such as contact time,pH, adsorbate concentration and adsorbent dose. The insignificant terms were assessed through student ‘t’ test and are remo...
Autori: Saroj Sundar Baral
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26084

AbstractThe present study was focused to classify various advanced oxidation processes (AOPs) to degrade sixteen commonpharmaceuticals and personal care products (PPCPs). The classification was based on the degradation rate constant (h-1).Chemometric techniques like principal component analysis (PCA) and cluster analysis (CA) were used to classify AOPs whichcan efficiently degrade a certain class of PPCPs. The bipolt based on first two principal components (PCs) of PCA modelidentified two distin...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26085

AbstractThe ozone oxidation and disinfection stages constitute important technological phases in the modern systems of water treatment,both as unitary stages as integrated ones into systems that use advanced oxidation processes (AOP). More than half of thewater/ozone contact systems used nowadays in the water treatment plants are based on systems of contact in the bubble column.This work here aims at experimentally analysing, in terms of scale, a water-ozone contact system in the bubble column a...
Autori: Sorin Claudiu Ulinici
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26088

AbstractA new approach to environmental protection management is the aerobic microbial digestion of food industry wastewaters byusing those waters as substrate, while the pollutants contained work also as oxygen-vectors. In biotechnology, oxygen masstransfer is a key parameter involved in the design and operation of mixing–sparging bioreactors and it can be analyzed by meansof the oxygen mass transfer coefficient (kLa). The influence of a second liquid phase with higher oxygen affinity (in this ...
Autori: Elena Folescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26097

AbstractThis paper presents the results of the research analyses and laboratory studies, aiming to develop design guidelines and suitabletechnologies for the construction of durable and environmental friendly rigid pavements by using recycled cement concrete,resulted from various demolition works. Various recycling principles and technologies, specific laboratory methods of improvedtechnical solutions to enhance wear coefficients, density homogeneity, mixture contamination and water absorption o...
Autori: Marius Muscalu
ISSN: 1843 - 3707Abstract This paper presents the results of the research analyses and laboratory studies, aiming to develop design guidelines and suitable technologies for the construction of durable and environmental friendly rigid pavements by using recycled
http://www.ecozone.ro/reviste.php?RID=26098

Abstract In many industrial applications most of the solid particles are separated by size and for this purpose there are used the oscillating sieves. The separation process based on sieves is a complex one and it depends on several factors, such as the properties of solid particles submitted to the separation process and on the operating regimes of the separating equipment. We have studied the separation process of the behaviour of solid particles on a flat oscillating surface...
Autori: Ovidiu Bontas
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26134

Abstract Large amount of radioactive sources generate gamma rays of various energies and intensities. Gamma-ray spectroscopy is applied for the quantitative study of the energy spectra of gamma-ray sources. In the present paper, a statistical analysis of the energy spectra of gamma-ray spectroscopy monitored during 4 years at the “Dosimetry and Radioprotection” Laboratory from ”Vasile Alecsandri” University of Bacău is provided. Several new mathematical parameters were calcula...
Autori: Marius Stamate
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26144

Abstract Biogas can be used as a renewable and green energy source by upgrading to natural gas. Water scrubbing, which is one of the most widely-applied upgrading technologies, involves an accurate knowledge of the solubility of the main biogas components in water, which is essential to the design and optimization of the biogas upgrading process. In this work, we use several thermodynamic models available in the Aspen Plus software modeling environment to calculate the solubilit...
Autori: Petronela Cozma
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26148

Abstract Municipal waste landfill leachate results in different stages of waste stabilization and has a negative impact on the environment. When implementing a new policy on waste handling, monitoring landfill leachate should be carried out under conditions of a modern solid waste landfill. The paper discusses the quality of leachate observed in old and recently built landfills in Vilnius - the capital city of Lithuania. The landfills are situated at a distance of 20 kilometres fro...
Autori: Kristina Baziene
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26151

Abstract The biosorption of Pb(II) and Cd(II) ions from aqueous solution on marine green algae biomass (Ulva lactuca sp.) was studied in batch systems, at initial solution pH of 5.0 and biomass dose of 8.0 g/L, considered as optimum experimental conditions. The obtained results from experiments of a single-component biosorption were analyzed using Langmuir, Freundlich and Dubinin- Radushkevich isotherm models. The Langmuir equation describe the biosorption isotherm of Pb(II) and Cd...
Autori: Laura Bulgariu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26152

AbstractDuring the normal operating of reservoir, the rock mass quality in hydro-fluctuation belt of reservoir bank will degrade graduallyunder the water-rock interaction because of the periodically impoundment and drainage. In this article, with the consideration ofthe change of water pressure, an experiment was performed to simulate the process of “immersion-air dry” cycles with sandstones selected from the hydro-fluctuation belt of Three Gorges reservoir area. Test results indicates that the ...
Autori: Huafeng Deng
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26161

AbstractBased on the method of images, the three-dimensional soil additive load formula caused by pipe jacking soil loss was derived byusing non-uniform soil displacement mode. Combining the formulas of additive load induced both by bulkhead additive thrust,force of friction between shield and soil, force of friction between follow-up pipes, which are based on the Mindlin solution, theformulas of total soil additive load were obtained. The distribution regularity of total additive load on adjace...
Autori: Gang Wei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26166

AbstractThermal behaviour, microstructure and mechanical properties of the clay polluted by acidic and alkaline pollutants wereinvestigated by thermogravimetric/differential thermal analysis (TG-DTA), scanning electronic microscope (SEM), mercuryintrusion experiments, permeability coefficient and unconfined compressive strength tests. The clay polluted by alkaline solutionpresented distinct exothermic peaks at 304-310oC, while it’s not observed for the one polluted by acidic solution due to thed...
Autori: Zhao Ying
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26182

AbstractThe removal of Acid Black 1 dye was investigated by acid treated pumice stone as a low cost adsorbent, since acidicmodifications were expected to improve the sorption capacity. The main components of the considered adsorbent were SiO2 andAl2O3 and acid treated pumice shows irregular structure. The effect of various parameters such as the initial dye concentration,the contact time, the temperature and the pH were studied. An increase of the contact time, the initial dye concentration or a...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26211

AbstractDespite the Moderate Resolution Imaging Spectrometer (MODIS/Aqua) presently collects data on operational basis, evaluationof its biogeochemical products from standard bio-optical algorithms is scare especially in Arctic waters. The present study isaimed to evaluate several MODIS/Aqua bio-optical algorithms and MODIS/Aqua remote sensing reflectance (Rrs) products inKongsfjorden waters on the western side of Svalbard, Arctic. Data sets consisting of in-situ measurements of radiometric quan...
Autori: Palanisamy Shanmugam
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26220

AbstractIn an urban environment, visibility strongly reflects human safety and welfare. Generally, visibility is dependent on particlescattering and absorption. The former is influenced by light wavelength, atmospheric gaseous species and particle characteristics,especially number and size distribution. Therefore, it is necessary to establish the relationship between visibility and particlecharacteristics. Furthermore, it is important to understand the formation mechanism of secondary aerosols. ...
Autori: Chih-Ming Ma
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26221

AbstractIn this article, hydrodynamic parameters and overall Oxygen mass transfer coefficient of petroleum based micro-emulsions in anairlift reactor were investigated. Four different petroleum-in-water micro-emulsion systems containing kerosene, heavy naphtha,light naphtha and diesel as oil based were used with concentrations of 3% and 7 % (v/v). The experimental data were supportedby simulation results obtained from the Computational Fluid Dynamics (CFD) method. The CFD was properly able to si...
Autori: Mostafa Keshavarz Moraveji
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26234

AbstractIn this work, a four factor three-level Box–Behnken factorial design based on response surface methodology (RSM) wasemployed to optimize the removal of phosphate from synthetic wastewater (mineral salts medium-MSM) by the bacterialconsortium (Bacillus sp. RS-1, Pseudomonas sp. YLW-7, Enterobacter sp. KLW-2). A mathematical model was then developedto show the effect of each medium composition and their interactions on phosphate removal. The effect of the lactoseconcentration (X1), pH (X2)...
Autori: Krishnaswamy Usharani
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26235

AbstractA novel RHA/PFA/CFA sorbent was developed by sol-gel method using three types of ashes, i.e. rice husk ash (RHA), palm oilfuel ash (PFA) and coal fly ash. From surface analysis of selected RHA/PFA/CFA sorbents, the spent sorbent had more compactstructures covered by irregular rough surface and the specific structure of raw RHA, PFA, and CFA were no longer visible. Inaddition, lower specific surface area was obtained for spent RHA/PFA/CFA sorbent. Batch studies were performed to evaluatet...
Autori: Irvan Dahlan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26272

AbstractThe removal and determination of toxic heavy metal ions in aqueous solutions has been given much more attention over the pastfew years. In this paper, a removal and separation/preconcentration method for cadmium species on Poly S15-g-EMA100 (a kind ofpolystyrene-graft-ethyl methacrylate copolymer) in water samples was developed. Some experimental parameters, such assolution pH, sample flow rate, type and concentration of eluent, amount of adsorbent and effect of common matrix ions werein...
Autori: Harun Ciftci
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26317

AbstractThis paper discussed the potential ecological risk, homologous relativity and spatial distribution of heavy metals in the waterlevel-fluctuating zone (WLFZ) of the Xiao River, a tributary of the Yangtze River. The Cd, Cu, Pb and Zn contents in the WLFZsoil were analyzed via atomic absorption spectroscopy. The potential ecological hazards of the heavy metals were also evaluatedusing the classical Lars Hakanson potential ecological risk index method. The average Cd, Cu, Pb and Zn contents ...
Autori: Chuan Fu, Dan Liu, Junjie Lin, Zhiguo Yu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26346

AbstractBased on the improved C-D production function model, the relationship of China’s energy consumption, economic growth andcarbon emissions are comprehensively studied in this paper through the panel data in China from1991 to 2009. The researchshows that energy consumption and economic growth have a long-term equilibrium and a one-way causality relationship fromenergy consumption to economic growth. In both elasticity coefficients and contributive rate, energy consumption plays the mostimpo...
Autori: Huifeng Pan, Jian-Min Wang, Li Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26370

AbstractThe electrochemical properties of two fluorinated substrates, namely 1H-3-methyl-4-ethoxycarbonyl-5-(4-fluorobenzylidenehydrazino)-pyrazole (Ia) and 1H-3-methyl-4-ethoxycarbonyl-5-(2-fluoro-benzylidenehydrazino)-pyrazole (Ib)respectively have been investigated in the room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluoroborateon a platinum electrode. The voltammetric investigation of the above compounds in the mentioned RTIL shows mainly twoirreversible anodic peaks...
Autori: Liviu-Virgil Costea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26471

AbstractTetracycline (TC) are used as bacteriostatic agents, inhibits the synthesis of bacterial proteins, with activity against awide variety of organisms with application in human and veterinary medicine. The presence of TC in theenvironment constitutes a serious problem, being weakly metabolized or absorbed into the human or animal bodycon. TC residues even in low concentration may produce serious toxic and other effects on humans and livingorganism. In this study are presented the applicatio...
Autori: Carmen Ionela Brînzilă
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26513

AbstractCurrently, thermal insulation of buildings is required from both an energy savings perspective and a money savings perspective.Insulation is primarily installed on the outer surface of the buildings. Weather and other circumstances can produce humidity thatcan act on the building structure, e.g., by changing its heat capacity, the heat transfer coefficient and/or other factors. As a result,it is important to measure the sorption behaviors of the construction materials. To perform sorptio...
Autori: Ferenc Szodrai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26550

AbstractHeavy metals in sludge have been one of the limiting factors for sludge reclamation, and therefore the changes of heavy metalsduring sludge treatment process should be concerned. This study investigated the detailed profile of changes of seven typicalheavy metals (As, Cd, Cr, Cu, Ni, Pb, and Hg) in the activated sludge during ultrasonic treatment process. The influences ofsonication time and ultrasonic power density were studied. Results showed that heavy metals in sludge were released i...
Autori: Tian Wan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26563

Abstract The present study deals with the removal of Cr (VI) from aqueous solution by polypyrrole (PPy). Response surface methodology (RSM) was applied for the design and analysis of experiments in the optimization of pH, temperature, initial concentration, contact time and adsorbent dose during the removal of the Cr (VI). The optimum adsorbent dose, temperature, initial concentration of Cr (VI), pH and contact time were found to be 0.8 g, 46.5 oC, 187.5 mg/L, 5.3 and 15.4 min respectively. ...
Autori: Ehsan Hasani
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26614

Abstract Samples were collected for six months (nine storm events) to observe the contaminant loads from three highway segments at Rawalpindi, Pakistan. The contaminants analyzed include total suspended solids (TSS), total dissolved solids (TDS), total nitrogen (TN), chemical oxygen demand (COD), total organic carbon (TOC), total phosphorous (TP), sulphate (SO4), chloride (Cl-), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), and chromium (Cr). Mass vs. volume [M (V)] curves were drawn to inve...
Autori: Hamid Iqbal
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26617

Abstract The objectives of this paper address the identification and statistical analysis of the laws underlying the variability of the magnitude of the damages to torrent control structures induced by four of the most well-known events affecting their stability, resistance and durability. The research set consists of 100 torrent control structures that have continuously functioned for almost three decades in a managed torrential watershed in the forested mountainous area of Romania. In the ...
Autori: Ioan Clinciu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26619

Abstract Adsorption equilibrium and effective diffusion coefficients of water vapor, in cylindrical particles of activated alumina (A) and activated alumina impregnated with calcium chloride (MCA), are experimentally determined. The experiments were conducted at 303 K and 323 K using cylindrical particles with 2.5 mm in both length and diameter. Diffusion coefficients were determined from the kinetics of water sorption. The measurements were conducted in a constant pressure unit based on a m...
Autori: Eugenia Teodora Iacob Tudose
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26665

Abstract The present work investigates the performance of Cristal-RightTM CR100 zeolite based on the equilibrium and thermodynamics water softening process. The commercial zeolite was characterized by scanning electron microscopy combined with energy dispersive X-ray spectroscopy and FT-IR spectroscopy. The equilibrium performances of zeolite were evaluated by the sorption capacity of calcium cations from calcium chloride solutions varying the calcium concentrations corresponding to moderate...
Autori: Liliana Lazăr
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26670

Abstract A novel sensitive and rapid analytical approach based on ultra-high performance liquid chromatography - mass spectrometry (UHPLC/MS/MS) tandem was developed for the monitoring of pentachlorophenol in water samples. Chromatographic separation was carried out on Acquity BEH C18 (100 x 2.1 mm, 1.7 μm) column under gradient mode using a mobile phase consisting of acetonitrile/ultrapure water/formic acid. Quantification of pentachlorophenol was performed on a triple-quadrupole tandem ...
Autori: Yassine Kadmi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26673

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 Mapping the distribution of populations has become an important issue in geographical and relative researchers. Combining population and spatial data allows for socio-graphic information to be visualized, in order to evaluate the total numbers of people at risk of environmental health hazards, who have died in natural disasters etc. Therefore, spatial distribution of population data is an effective way to integrate statistical and spatial data. This paper presents a multi-factor dat...
Autori: Yu Zhang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26686

Abstract This paper presents a medical diagnosis method, based on the interaction of the infrared laser beam and the human body, in a hospital environment, for inflammatory diseases, avoiding infected wastes. The main advantage of the laser bio-photometry is a rapid localization of the inflammation source, deep under the skin up to 5 cm, in emergency cases, when there is not enough time for classical medical procedures. Other advantages consist in the pollution absence for environment and pa...
Autori: Ala Bondarciuc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26696

Abstract This paper proposes an expert system based on Artificial Neural Networks (ANNs) to model road traffic noise. Feed-Forward Neural Networks (FFNNs) that are trained with the Levenberg-Marquardt back-propagation algorithm were used. Models were evaluated using mean squared error (MSE) and coefficient of determination (R2) as statistical performance parameters. In traffic noise modelling, the noise level at a receptor position due to the source of traffic emission is modelled as a funct...
Autori: Leila Khouban
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26700

Abstract Locally sourced clay from Kuala-Kangsar town in Perak state Malaysia was used in both its raw (RKKC) and modified (MKKC) form as adsorbents for the removal of methylene blue (MB) from synthetic textile wastewater in batch adsorption process. The raw clay was modified through H2SO4 acid treatment, Al(OH)3 ion exchange, calcinations and then molded into beads before freeze drying. The BET surface areas of RKKC and MKKC were 11 and 100 m2/g, respectively; their elemental analysis and ...
Autori: Manase Auta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26717

Abstract Planktonic algal samples were collected from lakes with different salinity (Salt Lake Brăila, Amara Lake, Fundata Lake, Techirghiol Lake and Black Lake-Sovata), in which mud used in balneary therapy is formed. A total of 189 species were recorded: 35 Cyanobacteria, 10 Euglenophyceae, 96 Bacillariophyceae, 33 Chlorophyceae, 3 Chrysophyceae, 2 Cryptophyceae, 1 Xantophyceae and 9 Dinophyceae. The highest number of phytoplankton species was recorded in Techirghiol lake (127 species...
Autori: Liana Gheorghievici
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26719

Abstract This paper aims to analyze the characteristic of Road deposited sediment (RDS) using West Chang Tan highway, Hunan, China as a study site. RDS samples were collected at five representative highway sites and the particle size distribution was generally less than 150μm. Particles with the grain size (<150μm) had high metal concentrations among all sampling sites (unit: mg/kg): Cu 74-178, Zn 309-2737, Pb 601-1160, Cd 9.8-44.5. There is significant spatial variability between t...
Autori: Yunbo Zhai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26728

Abstract Every day, millions of people are exposed to noise at work and to all the associated risks. It is a clear fact that the noise is an important problem in the industrial areas and moreover it becomes a significant issue in a wide range of other non-industrial environments as well. The current trend in the construction of gearboxes, regarding the speed increasing, favors the increase of the dynamic loads, which are accompanying the operation of equipments. The dynamic contact phenomen...
Autori: Zoltan Iosif Korka
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26765

Abstract On the basis of a generalized irreversible Carnot heat engine (GICHE) model with the losses of heat resistance, heat leakage and internal irreversibility, the local stability of the heat engine at the maximum ecological function (MEF) is studied with Newton’s heat transfer law between working fluid and heat reservoirs. It is derived that a general expression of relaxation time described as stability of the system refers to heat capacity C, overall heat transfer surface area F,...
Autori: Lingen Chen
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26859

In this study, response surface methodology (RSM) method was applied based on a five-level and four-variable central composite design. The optimization of the C.I. Direct Red 81 (DR81) removal by the combination of electrocoagulation (EC) and UV processes was also performed. The effect of initial pH, reaction time, current density and initial dye concentration on the dye removal was investigated to obtain the optimal experimental conditions. The optimal conditions with the dye removal of 95% ...
Autori: Elmira Pajootan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26942

Over the past three decades, nickel–titanium engine-driven files have become instruments “sine qua non” for root canal treatment. They are increasingly used by dentists to facilitate the cleaning and shaping of root canals, during the mechanical treatment phase in endodontic therapy, increasing not only the speed of the treatment but also assuring a proper shape of the canal preparation. During the repeated use of these instruments, separation of the file occurs. It has been...
Autori: Teodora Stefanescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27024

This paper presents a research on ways to reduce waste and to diminish sound pollution by recovery of fir sawdust and recycled rubber granules and use in making sound absorbing composite materials. Four materials were prepared using raw materials (fir sawdust and recycled rubber granules) in various percentages, and polyurethane binder. Materials mechanical and acoustic properties were characterized, proving these materials have useful properties. Materials acoustic performance was compared w...
Autori: Ancuţa Elena Tiuc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27039

This paper focuses on the testing and comparison of the sensitivity of vegetation indices to determine the changes occurred in forest areas of the Cluj Forest District during the post-socialist period, between 1986 and 2009. Concurrently, the paper pursues to assess the way in which the socio-economic and social changes have caused alterations of the forest areas. These have been significantly affected by the changes occurred over the past decades, as well as by the increase of the anthropiza...
Autori: Paula Furtună
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27061

Triton X-100 (TX100) and Tween 80 (TW80) were used to study the decontamination of polycyclic aromatic hydrocarbons (PAHs) in the bulk and different size fractions of soil samples from a former coke oven plant. The effects of PAH ring number, initial concentration and soil total organic carbon (TOC)/black carbon (BC) contents on PAH removal efficiencies were analyzed. Surfactant washing for the bulk sample showed clear relation between the removal efficiency and PAH ring number. When the sur...
Autori: Helian Li
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27093

This study proposes a modified fractional fuzzy simulation (MFFS) method to predict the toluene and oxygen concentrations in aquifers under microbial attenuation conditions. The method integrates the modeling of groundwater flow contaminant transport and fuzzy parameters analysis within a general framework. Compared to conventional fractional fuzzy simulation (FFS), decreased interior points of fuzzy parameters need to be used, thus reducing the simulation time. The method is applied to an a...
Autori: Li He
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27106

Hydraulic modelling makes possible the identification of floodplain areas for flash floods with discharge of different return periods. High resolution DEMs allow river bed geometry identification, while prior hydrologic modeling results can serve as input data for the hydraulic model. Once the river bed and floodplain roughness coefficient are set, the floodplains can be delineated on the base of MIKE11 model. For the present study the authors have used three gauged small rivers situated in t...
Autori: Maria-Mihaela Győri
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27115

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

The adsorbent gels utilized in this research project were synthesized from non-commercially available chitosan, obtained by deacetylation of chitin, which was isolated from fermented shrimp waste by a major local industrial food biopolymer. Chitosan-based adsorbent gels were used for the removal of a tris-azo dye (Direct Blue 71) from aqueous solutions. Sorption experiments focused on the chemical modification of chitosan using two cross-linking agents, sodium tripolyphosphate (TPP) and glutaral...
Autori: Reyna G. Sánchez-Duarte
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27184

A new simple empirical model is proposed to describe the waste sludge volumetric flow rate in the steady-state completely mixed activated sludge process. The model is derived based on the nonlinear regression analysis by using the Richardson’s extrapolation method and the Levenberg–Marquardt algorithm. The application of the model has been explored for a wide range of eleven fundamental biological design variables and tested against a total of 1500 additional computational scenarios ...
Autori: Kaan Yetilmezsoy
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27202

This paper examined some physical and mechanical properties of wood from thin trees of sessile oak collected from thinning operations, in order to recommend this secondary wood resource for potential superior applications (as solid wood panels and furniture components). Swelling, shrinkage, modulus of rupture (MOR) and modulus of elasticity (MOE) and compression strength parallel to the grain were examined and compared with data from literature reported for mature trees. The variation of the abo...
Autori: Alin M. Olărescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27210

In this study, the biosorption of zinc(II) ions from the aqueous solutions by the lichen biomass of Xanthoria parietina (L.) Th. Fr. was studied as a function of contact time, initial pH of metal solution, biosorbent concentration, initial metal ion concentration and stirring speed in a batch system. The optimum pH value for maximum zinc biosorption was found to be 5.5. Concentrations intervals from 50 mg/L to 250 mg/L were tested and it was observed that the biosorption efficiency depends on th...
Autori: Zuleyha Bingul
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27213

In this study, an upflow anaerobic sludge blanket (UASB) bioreactor at the mesophilic temperature (38ºC) was successfully used for the treatment of petroleum refinery effluents. Response surface methodology (RSM) was applied for the design and analysis of experiments to predict the behavior of the initial COD and the hydraulic retention time (HRT) in the bioreactor. A statistical analysis indicated that the models adequately represented the experimental data. At the optimal conditions, the ...
Autori: Seyed Omid Rastegar
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27233

In this article we present the results of the study concerning the relationship between the concentration of trace elements (lead, chromium, cadmium, cobalt, copper, zinc and nickel) in soil and in the leaves and bark of Populus nigra L. The samples were collected in the period May 2010 – October 2010 in two areas from the Romanian North Littoral of Black Sea. The concentrations of the trace elements in soil, leaves and bark were determined using Flame Atomic Absorption Spectrometry (F...
Autori: Lucica Barbeş
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27239

The necessary oxygen concentration for the biological process depends on the organic matter present in wastewater characterized by organic matter reaction rate with oxygen, k. This article highlights the impact of the reaction coefficient on oxygen dispersion in water. The first stage of the research led to the determination of the ratio between the coefficient of reaction and the coefficient of dispersion on the vertical of the tank as k/εz ϵ [0.066 - 0.79]. Starting from this rat...
Autori: Corina Boncescu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27298

According to literature, aggregate stability of soils is influenced by: particle size and soil texture, soil structure, content of Ca2+ and Mg2+, mineral clay type, soil content of organic matter, soil processing degree. This paper aims to investigate the influence of some physical, microbiological and chemical properties of saline soil concerning water-stable aggregate. The hydro system stability of the aggregates appears in the specialized studies as having a positive correlation with microorg...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27300

Climate and environmental conditions primarily affect the yield and quality of agricultural products. Turkey’s environment shows different characteristics between regions because of the position of the Turkey in the World. In the agricultural product industry, different techniques are used to measure the physical properties (diameter) of the agricultural products to determine the effect of the climatic difference between regions on the quality of goods. Many factors affect the classificati...
Autori: Metin Dağtekin
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27308

The paper aims to present the sorption properties of two sorbent substrates (composts) prepared by aerobic fermentation from vegetables waste composted with beech sawdust (BR2) and beech ash (BC1) to be used for Cu2+ removal from wastewaters. The composts structures and surface properties were characterised in terms of active groups (FTIR), crystallinity (XRD), morphology (SEM), topography (AFM) and specific surface and pores analysis (BET), and the changes in properties after Cu2+ sorption were...
Autori: Ileana Manciulea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27323

This study was to optimize the fermentation process for protein enrichment of potato starch residue (PSR) by solid state fermentation with mixed strains. Three single-factor experiments were conducted to optimize the fermentation conditions, and a Plackett-Burman design followed by a central composite design of response surface methodology was investigated to optimize the medium constituents. The optimal fermentation conditions were fermentation temperature 28°C, fermentation period 72 h and...
Autori: Heng Lei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27380

The main objective of this study was to investigate the potential utilization of polyethylene terephthalate PET waste in cementitious matrix, as substituent to cement, to develop lightweight construction materials and for preventing chemical attacks or repairing various reinforced concrete structures. Composites containing different amounts of PET particles, as partial replacement to cement by weight, were characterized by destructive and non-destructive testing. So, the thermal conductivity, ul...
Autori: Ahmed Soufiane Benosman
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27381

This work presents an experimental analysis of the influence of a monocrystalline photovoltaic (PV) panels’ temperature on its main operating parameters. Victron Energy, SPM 30-12 PV panel is tested, using a double climatic chamber. The PV panel is placed as a barrier between the two rooms of the climatic chamber. The study is focused on the establishing the effect of raising temperature of PV panel over electrical parameters: voltage, current and power produced and also over the effici...
Autori: Sebastian Valeriu Hudisteanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27397

Cascade dams alter the movement and accumulation of heavy metals in sediments along the river continuum. 27 sample crosssections were taken in July 2011 from the Xiaowan, Manwan, and Dachaoshan dams in the middle reach of the Mekong River in southern China and analyzed for content of heavy metal (Zn, Cr, Pb, As, Cu, Ni, and Cd) concentrations in the dammed river reach. There were evident spatial variations of the heavy metal concentrations downstream and upstream of the three cascade dams; t...
Autori: Li Deng
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27436

The Artificial Neural Network (ANN) model was used to predict dye (Reactive Blue 19) removal efficiency from aqueous solution using modified pomegranate residual based on 124 experimental sets. Three-layer ANN models with different neurons numbers at a hidden layer were developed. The optimum network yielded a network error of 0.0054 and 0.9606 for mean square error and coefficient of determination, respectively. Furthermore, sensitivity analysis of the network revealed that the adsorbent do...
Autori: Elham Radaei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27439

This study analyses the relationship between the scattering properties and the chemical compounds internal mixture of the aerosols near Bucharest, Romania. Several cases of local aerosols influenced by heating sources, like wood or fossil fuel, are characterized in order to retrieve the winter period specificity. Correlation between organic and inorganic aerosols composition from mass spectrometry measurements made with Compact Time (CT) of Flight Aerosol Mass Spectrometer (AMS) and scatteri...
Autori: Luminita Marmureanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27444

The aim of this study was to examine the adsorption of malachite green dye from aqueous solutions on the waste foundry sand. The effects of contact time, adsorbent amount, pH and initial dye concentration were investigated. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin adsorption isotherm models. The adsorption capacity of waste foundry sand for the removal of malachite green dye was determined with the Langmuir and found to be 23.29 mg/g. The adsorption isothe...
Autori: Elif Hatice Gürkan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27536

A micelle-mediated preconcentration method has been developed for determination of Safranine T at trace amounts, which is widely used in textile industry. It can be evaluated as one of the dangereous chemicalsdue to its carcinogenicity and toxic properties. The method is based on the cloud point extraction (CPE) of Safranine T at pH 8.0 in the presence of Triton X-114 as nonionic surfactant. The obtained surfactant–rich phase (SRP) was diluted with ethanol and its absorbance was measured ...
Autori: Songül Ulusoy
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27538

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

The solid-liquid extraction process and some of its influencing factors such as solid-liquid ratio, temperature and salt initial amount have been investigated. Also, mathematical modeling for mass transfer coefficients calculation was applied. An inert porous solid material (coal), impregnated with 10% and 20% mass NaCl or 15% and 30% mass CaCl2, was used. The leaching was conducted in a fixed bed column, in laminar flow. The CaCl2 impregnated samples were investigated in a column with a height...
Autori: Marcel Popa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27557

This paper proposes a study on the estimation of daily solar irradiation (global and diffuse irradiation) under real-sky conditions and the validation of proposed estimation models by analyzing the most important statistical indicators. Two types of regressions are proposed for the estimation of solar daily global irradiation; the first type is based on the second order degree Ångström-Prescott correlations; the second type uses the second order Ångström-Prescott correla...
Autori: Elena Eftimie
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27670

Sulfide bearing mine tailings generated through mining and processing of mineral ores is one of the serious problems around the world due to their potential environmental hazards. Current study focuses on vertical distribution and potential mobility of metals in New and Old tailings of a Lead and Zinc mining area of India. Mine tailing profiles sampled from New (0-500mm) and Old tailing (0-400mm) dams were chemically (pH, EC, Carbonate content, Cd, Pb, Zn and Mn levels) and mineralogically (usin...
Autori: Malik Anju
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27690

Bottled water (commonly called mineral) makes an important source of minerals for humans. Its consumption has been systematically rising in the highly industrialized countries, even though not every water type has appropriate health properties. As a result, drinking bottled water ought to be supported with understanding its qualities and physicochemical content. The following article presents the results of the research into pH levels, electrical conductivity, selected inorganic anions (F-, Cl-...
Autori: Rajmund Michalski
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27693

The adsorption rate and dynamic behavior of the system are important factors as regards the process design and operational control. The aim of this study was to find a suitable kinetic model for the hexavalent chromium removal in a batch reactor. The experimental data were analyzed using four adsorption kinetic models: the pseudo- first and second order equations, the Elovich equation, and the intraparticle diffusion equation, so as to determine the best fit equation of the Cr(VI) adsorption ont...
Autori: Ankica Radjenovic
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27773

Geocomposite materials consisting of lightly cemented mixtures of expanded polystyrene beads (EPS) and backfill soils are commonly used as fillers and for the construction of light weight embankments. The constant normal stress (CNS) and constant volume (CV) direct shear parameters as well as the relationship between gradation properties of four residual granular backfill soils and direct shear parameters of lightly cemented mixture of EPS and backfill soils was evaluated. The maximum density an...
Autori: Felix Okonta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27771

Influence of soil pH on the mechanical characteristics of glass reinforced plastic (GRP) pipes type was often investigated in different situations encountered in the field. GRP degradation is directly proportional to the exposure to soil with non-neutral reaction. The theoretical and experimental results lead during time to design standards, which allow the application of GRP pipes in water and soil, so as minimum interferences with the materials used in the manufacture of pipes would appear. Sa...
Autori: Ana Diana Ancas
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27768

Bare zero-valent iron nanoparticles (bare-ZVIN) have a great tendency to aggregate, which drops their reactivity with pollutants. To address this issue, polyvinylpyrrolidone stabilized-ZVIN (PVP-ZVIN) was synthesized and used for the removal of Cd2+ from aqueous solution in a batch system. The effects of operation conditions such as the pH of aqueous solution (2-8), reaction time (0-120), adsorbent concentration (1-6 g L-1) and the initial Cd2+ concentration (10-60 mg L-1) on the removal efficie...
Autori: Amirhosein Ramazanpour Esfahani
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27764

6In this paper, an application artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) are presented to predict the heat transfer rate and effectiveness in the corrugated plate heat exchangers. First, the thermal performances of the corrugated plate heat exchangers were evaluated experimentally. Experimental data were used for training and testing network. The results of the ANN are compared with the ANFIS in which the same data sets are used. The ANN model is slight...
Autori: Bayram Kılıç
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27763

This study was conducted to screen plants growing on potentially contaminated areas of landfill body and nearest surrounding to determine their potential for metal accumulation. In addition, enrichment coefficient (EC) for plant/soil system, correlation and principal component analysis were used for determining the environmental contamination from landfill in terms of heavy metal (HM) accumulation. The examined plant samples meet the stated requirements. The highest values in samples 1 - 8 reach...
Autori: Magdalena Daria Vaverková
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27752

Debris from deciduous trees in the form of park green waste was investigated as a potential biosorbent for the removal of chlorinated solvents from water. The sorption properties of beech leaves and cupules, oak leaves and acorns, birch leaves and lime leaves (all tree species common for a moderate climate) in a non-modified form were investigated with regard to the removal of perchloroethylene, 1,1,2-trichloroethane and 1,1,1,2-tetrachlorothane. The preliminary results showed that these biosorb...
Autori: Marek Tobiszewski
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27760

Changes in material properties are examined in this work by vibration diagnostic techniques. In the article examinations of soft poly(vinyl chloride) (PVC) fibers, which were tested as vibrating strings are presented after different UV light induced aging times. The developed experimental system is presented in this manuscript and the main goal is to determine material changes as the results of artificial aging by special vibration diagnostic methods. The damped oscillations, where PVC fibers ar...
Autori: Dénes Kocsis
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27841

The synthesis of dimethylamino-propylamine pullulan, DMAPA-P, with a substitution degree of 0.4 was performed in dimethylsulfoxide using N,N’-carbonyldiimidazole as activator and dimethylaminopropylamine as amination agent. Then, two quaternary derivatives (trimethylammonium-propylamine pullulan, TMAPA-P, and benzyldimethylammonium-propylamine pullulan, BzDMAPA-P) were prepared from DMAPA-P by quaternization with methyl iodide and benzyl chloride. The behavior of new pullulan derivativ...
Autori: Anca Giorgiana Grigoras
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27902

In this study, Mg-doped ZnO nanoparticles with 2% Mg content were synthesized by sol-gel method. The structure and morphology of the nanoparticles were characterized by TEM, BET and UV-Vis absorbance techniques. From TEM image, it was found out that the nanoparticles had uniform size and uniform distribution. BET analysis revealed that in comparison with pure ZnO, Mg 2%/ZnO nanoparticles had a higher specific surface area. Based on UV-Vis absorbance analysis, Mg 2%/ZnO nanoparticles shifted t...
Autori: Nahide Zarei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27909

In this study we investigated the possibilities of using recyclable fine and coarse grain waste obtained by grinding Polyethylene Terephthalate (PET) containers, as light filling materials for different applications (clay dams, highway embankments, and backfills behind retaining structures. Various geotechnical tests were performed on clayey soil and soil-PET mixtures using recycled fine and coarse granules of Polyethylene Terephthalate bottles. The results indicated that the use of the recyc...
Autori: Osman Gunaydin
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27920

The theoretical and computational studies of dye sensitized solar cells (DSSCs) can contribute to a deeper understanding of these types of solar cells. The DSSCs are the novel design of solar cells which could be used as power producing windows or skylights. They represent a particular promising approach to a direct conversion of sunlight into electrical energy at low cost and with high efficiency. The light adsorption occurs in dye molecules adsorbed on a highly porous structure of TiO2 film...
Autori: Nnditshedzeni Eric Maluta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27932

For assessing the intrinsic safety to mechanical sparks, two dedicated methods are implemented in testing laboratories and further used for the conformity assessment of products with regard to explosive atmospheres ignition, namely: impact test and friction test. The purpose of the article is to present the results obtained by using the first method mentioned, results which shall be applied in further research for comparison with the ones resulting from the friction test. The article presents...
Autori: Adrian Marius Jurca
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27957

Dairy wastewater has been a major environmental concern because of massive effluents characterized by high pollution load. This study reports the influence of initial pH (pHi), residence time (τ) and elapsed time (t) on the %COD removal (Y1) and specific energy consumed (kWh per kg of COD removed, Y2) for real dairy industry wastewater treatment in continuous stirred tank electrochemical reactor (CSTER) using aluminum electrodes. Central composite design (CCD) was applied for designing th...
Autori: Poonam Kumari
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28011

Trace elements (TEs) in contaminated soils are considered as primary jeopardy issues in developing countries which can cause major concerns for this industry and also menace the surrounding ecosystems, human health and wildlife, so urgent reclamation methods are required. The present research aims to evaluate potential phytoremediation capability of selected plant species Tamarix Spp., Haloxylon Spp. and Malcolmia Africana to grow in TE contaminated soils. Muteh Gold mine, a widespread mountaino...
Autori: Ali Daryabeigi Zand
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28056

In the present research, the intensity of contamination with heavy elements Vanadium (V) and Arsenic (As) in the coastal sediments of Bandar Abbas is gauged and rated using the method of Atomic Absorption Spectroscopy. All processes of sampling and assimilation of sediments are performed according to the guideline of the Manual of Oceanographic Observations and Pollutant Analyses Methods (MOOPAM) Standard issued by the Regional Organization for the Protection of the Marine Environment (RAPMI).T...
Autori: Akbar Elsagh
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28105

Based on the interpretation of LUCC data, through the correction of basic equivalent value and value equivalent coefficient, this study sets up the evaluation system based on value transfer method, and realizes the dynamic evaluation of wetland ecosystem nservices value in Jiangbei New Area, i.e., the value of wetland ecosystem services in Jiangbei New Area was RMB 6,060.77 million, RMB 9,244.62 million and RMB 7709.68 million respectively in 2002, 2009 and 2017, which show obvious fluctuation ...
Autori: Shu Tang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28109

Deforestation and changes in forest cover are subject to the effects of many factors: economic, social, cultural, political, and environmental and their interactions. To assess these factors, one should necessarily know their nature and then model them. Nowadays many models have been introduced to explore deforestation, however most of them are based on past events and do not pay enough attention to socioeconomic factors. Moreover, considering the future is sometimes absent in those models. The ...
Autori: Maryam Jadidi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28112

The present study represents an extension of ergosterol production by Saccharomyces cerevisiae fermentation processes using oxygen-vector by establishing the influence of the analyzed main factors, such as aeration efficiency and hydrocarbon concentration. The study has been developed for batch and fed-batch fermentation systems and has been focused on the variation of ergosterol content inside the yeast cells during the fermentation cycle in correlation with hydrocarbon volumetric fraction, COV...
Autori: Corina Ciobanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28130

Soluble dyes are intensively used in various industrial activities. They represent an important class of water pollutants from which they are rather difficult to remove. This paper focusses on the elimination of Congo Red (CR) ionic azo dye by adsorption on a low cost material. Cherry stones were used for activated carbon preparation by carbonization method. A temperature of 600 °C and a time of 4 h were found as adequate parameters for the physical activation and led to a final white powder...
Autori: Cristina-Gabriela Grigoraș
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28153

The objective of the present work was to introduce a novel adsorbent with high adsorption potential toward methylene blue by decorating montmorillonite clay (MMT clay) with Zn(OH)2–nanoparticles (Zn(OH)2–NPs). The adsorbent was characterized structurally by FE-SEM and FTIR techniques. Central composite design–response surface methodology was applied to optimize experimental variables including adsorbent dosage, pH, initial MB concentration, NaCl concentration, and sonication ti...
Autori: Adel Valipour
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28173

The heavy dependence on fossil-based energy and inefficient use of energy add to the relentless growth of carbon emissions in China, and also lead to an array of serious environmental pollution issues, such as haze and smog. This situation threatens the health of residents and the sustainable development of society. China has to face the huge pressure of carbon emissions from international and domestic societies. This study aims to investigate the demographic driving factors of carbon emission ...
Autori: Yan Li
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28265

In order to study the influence of different rainfall processes on the total pollutant load of non-point sources and pollutant load reduction rate of the low-impact development facilities, this paper took a Low Impact Development (LID) community of Tianfuheyuan, Fengxi new city, Xixian new district in Shaanxi, China as an example, and constructed the storm water management model (SWMM) of the study area. The computed results demonstrate that the storm patterns have obvious effects on the polluta...
Autori: Yu Tong
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28321

This research applied passive air pollution samplers to monitor the concentration of the pollutants nitrogen dioxide (NO2) and ozone (O3) in order to investigate the relationships between pollutant concentrations and meteorological variables. The study was carried out in three strategic sites in the municipality of Erechim, Brazil, which provide intense traffic of small and large vehicles. The pollutant analyses were performed using the method of UV/VIS spectrophotometry. NO2 concentrations vari...
Autori: Eduardo Pavan Korf
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28326

The study presents the experimental testing of a heat exchanger with uniform thermal flux (HEUTF), used as a cold source in HVAC systems with heat pumps. A water-water heat exchanger is tested, having a special geometry, with uniform thermal flux along the system. The heat exchanger proposed consists of a distributor and a collector, connected to each other by means of 20 staggered copper pipes, being suitable for serving low or medium geothermal sources. The innovation consists in the uniformit...
Autori: Sebastian Valeriu Hudișteanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28340