This article assesses the surface water quality of the Strîmtori-Firiza reservoir by analyzing 14 physicochemical parameters among 9 metals in 18 sampling points. A series of possible reservoir pollutants were identified, depending on the nature of the pollutants and their loading. The novelty of the paper consists in the broad spectrum of investigations that includes spatial distribution cluster analysis and mathematical modeling. This article presents an innovative method of assessing the distributions of the metal loads as maps of metal distribution that are in accordance with the developed mathematical models that aim to present the pollutant distribution and the degree of correlation between the physicochemical indicators. The clusters were generated using Ward's and Nearest Neighbor methods that are less used in the studies concerning the analysis of water quality. Measures for maintaining the quality of the water reservoir are proposed considering the importance of the reservoir as source for drinking/industrial water.
The molar refraction, polarizability, and refractive index for a series of monocarboxylic, dicarboxylic, and unsaturated monocarboxylic acids, having a symmetric or asymmetric structure, were investigated by the application of quantitative structure property relationship (QSPR) technique. We used a linear regression method and a single molecular descriptor, the ZEP topological index, calculated in a simple manner, with the help of weighted electronic distances, and also calculated on the basis of the chemical structure of the molecules. The high-quality performance and predictive ability of the QSPR models obtained were validated by means of specific validation techniques: y-randomization test, the leave-one-out cross validation procedure, and external validation. The investigated properties are well modeled (with r2 > 0.99) by the ZEP index, using the regression analysis as a statistical tool for developing reliable QSPR models. Our approach provides an alternative technique to the existing additive methods for predicting the molar refraction and polarizability of carboxylic acids, which is essentially based on the summation of atom and/or functional group contributions or bond contributions, and of some correction increments.
The need to reduce pollution to levels that minimize adverse effects on human health involve the monitoring of air quality, including dry depositions and their metal content. The analysis of these parameters aims to investigate the air quality in Maramures County (with nonferrous mining activities) and in the Romanian - Ukraine transboundary area. The paper presents the experimental results obtained for dry atmospheric deposition of copper and zinc using flame atomic absorption spectrometry (FAAS). The samples were collected from four location/cities of Maramures County (Baia Mare, Sighetu Marmatiei, Viseu de Sus and Borsa) during May-October 2014. The highest average values of copper concentration in the dry depositions were found in Baia Mare (199.88 μg/g), that is the most important industrial centre in Maramures County, followed by Borsa (111.49 μg/g), that used to be a nonferrous mining centre. In Viseu de Sus and Sighetu Marmatiei the average concentrations of copper in the dry depositions were lower: 75.63 μg/g and 64.26 μg/g, respectively. Zn average concentrations in dry depositions were 6.4-12 times higher than Cu concentrations. In Viseu de Sus and Borsa relative high values of Pearson correlation coefficients between the logarithm of Cu and Zn content in the dry deposition were found (0.702 and 0.737, respectively) estimating that both pollutants in the ambient air have the same sources, probably the re-suspension of the dust from the tailing ponds. This study is implemented within the frame of ENPI Cross-border Cooperation Programme Hungary-Slovakia-Romania-Ukraine 2007-2013, in the project Clean Air Management in the Romania-Ukraine Transboundary Area - (CLAMROUA), financed by the European Union
Sweet, semi-dry and semi-sweet red wine samples from two vine-growing regions in Romania:Vrancea and Recaș were analyzed aiming to show their main chemical properties including heavy metal content, and, microbiological characteristics. The chemical analysis showed that the semidry wine (W1) has a high polyphenol content, permanganate index and content of Fe, Zn and Cu, but the lowest content of anthocyanins, sugar and Mn; the total acidity of semi-sweet wine W3 was the highest, while the semi-sweet wine W2 contained the highest concentrations of anthocyanins and SO2. No contamination with yeasts, molds and bacteria was found when opening the wine bottles, these colonies having grown one month after opening. The importance of this article comes from the comprehensive presentation of the connections among the physicochemical and microbiological characteristics of sweet to semi-sweet red wines, or to semi-dry from two vinegrowing regions in Romania: Vrancea and Recaș.
Polyphenols are the main contributors for the wines color and also for others characteristics of wines such as astringency and bitterness. Samples of wines (red and white) were analyzed following to assess their polyphenols and anthocyanin's content in relation with their color characteristics. The properties of red (Fetească Neagră) and white wines (Fetească Albă from Cotnari vineyard) were compared to the wine made of grape hybrid cultivar Othello. Also the grape must obtained of hybrid cultivar Othello was analyzed. Polyphenols and anthocyanins were assessed by UV-VIS spectrophotometric methods. Polyphenols content was analyzed using Folin-Ciocalteu method and was expressed as gallic acid. Calibration with gallic acid as standard polyphenolic substance was previously performed. The method for determining anthocyanins is based on their property to be discolored by sulfites. Permanganate index was also determined to evaluate the reducing characteristics of wines by titration against potassium permanganate in the presence of Indigo carmine as redox indicator. Glories chromatic parameters such as color intensity, tonality, %Yellow, %Red and %Blue were established. Polyphenol of the analyzed wines ranged between 47-2653 mg/L polyphenols while the anthocyanins were 0-245 mg/L. Permanganate index was in the range of 14-87 ml KMnO 4 /L. The polyphenols content of the wine made of hybrid cultivar Othello was lower than that of red wine (Fetească Neagră). The color intensity was significant lower than that of Feteasca Neagră wines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.