Babes-Bolyai University Collection Repository
Babes-Bolyai University Collection Repository is a digital platform dedicated to collecting, preserving, and sharing academic works and research. This repository provides open access to a wide range of resources, including theses, scientific articles, and educational materials.
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- With a history of more than six decades (1955), Studia Universitatis Babeș-Bolyai (Studia UBB) is one of the leading academic journals in Romania. Published as early as 1955 in Social Sciences series and Natural Sciences series of the Newsletter of “V. Babeș” and “Bolyai” Universities, Cluj, the journal merged, in 1957, in Studia Universitatum Victor Babeş et Bolyai, and, in 1958, in Studia Universitatis Babeș-Bolyai. Since 1962, Studia UBB has been published as a separate series (with a brief hiatus in 1974, when it was again reunited multiple series). The journal was gradually modernised after 2000, reflecting its inclusion into a broader, global academic culture, a diversification of research areas, an openness to more varied theoretical approaches, as well as hospitality to cutting-edge, innovative studies. Studia UBB is currently edited in 29 diamond open access journals (series). All articles published in Studia UBB are fully open access: immediately freely available to read, download and share. Articles are published under the terms of a Creative Commons license which permits, without charge, use, distribution and reproduction in any medium, provided the original work is properly cited. Studia UBB does not charge authors any kind of publication fees or article processing charges.
Recent Submissions
INFLUENCE OF THE Ni/Mg RATIO ON THE COLOUR OF SPINEL PIGMENTS PREPARED BY A MODIFIED SOL – GEL METHOD
(STUDIA UBB CHEMIA. Published by Babeş-Bolyai University, 2017-03-30) Firuța GOGA; Roxana DUDRIC; Liliana BIZO; Alexandra AVRAM; Alexandru-Horațiu MARINCAȘ; Csaba VARHELY Jr.; Thomas DIPPONG
This paper focuses on the synthesis and analysis of some spinel-structured, ceramic pigment nanopowders (Mg(1-x)NiₓAl₂O₄) using a modified sol – gel method. This study emphasizes the influence of the Ni/Mg ratio and that of the thermal treatment on the properties of the obtained powders. The behavior of the dried gels during calcination was studied by differential thermal analysis. The formation of the spinel structure after calcination was analyzed using x-ray diffraction. The colour of the powders was characterized by UV – VIS spectroscopy, determining the absorption spectra. In addition, the trichromatic coordinates were determined, and the corresponding pigment positions were fixed on the chromaticity diagram.
INVESTIGATION OF TITANIUM-DIOXIDE COATINGS ON MEMBRANE FILTRATION PROPERTIES
(STUDIA UBB CHEMIA. Published by Babeş-Bolyai University, 2017-03-30) Ildikó KOVÁCS; Sándor BESZÉDES; Szabolcs KERTÉSZ; Gábor VERÉB; Cecilia HODÚR; Ibolya Zita PAPP; Ákos KUKOVECZ; Zsuzsanna LÁSZLÓ
In this study, synthesized TiO₂ nanorods and commercial Aeroxide P25 TiO₂ nanoparticles were deposited on polyethersulfone (PES) membrane surfaces to compare their photocatalytic activity and effects on membrane surface and filtration properties. The catalysts were deposited on the membrane surface by physical deposition. The effect of the TiO₂ amount on the stability of the catalyst layer and its effect on membrane resistance in presence and absence of UV irradiation were investigated. 1.2 mg/cm² catalyst coverage proved to be a minimal appropriate coverage to prevent membrane damage during UV irradiation. The catalysts formed hydrophilic layers on the surface, and in case of both catalyst the surface free energy increased compared to the neat membrane. The photocatalytic activity and retention of the modified membranes were tested spectrophotometrically by using Acid Red1, azo dye.
INVESTIGATION OF THE EFFECT OF A HYBRID DRYING METHOD ON THE COLOR QUALITY OF NECTARINE SLICES AND ENERGY CONSUMPTION
(STUDIA UBB CHEMIA. Published by Babeş-Bolyai University, 2017-03-30) Fatmagül Mutlu DEMIREL; Osman İSMAIL
The main objective of a product quality study for drying agricultural products without causing distortion is to reduce the product moisture value to a final moisture value while expending the least energy and time. In the first stage of this study, nectarine slices were dried in a microwave and cabinet dryer under different drying conditions. Experiments in the microwave dryer were done at four different power levels: 90, 180, 360, and 600 W. Hot air drying was done at two temperatures, 50 and 70 °C, with a constant air velocity (2.0 m/s). In the second stage, after those experiments, the hybrid drying method were constructed based on the color parameter, and moisture ratio. In the hybrid drying method, hot air drying was carried out with microwave pretreatment. The most effective hybrid drying method in terms of optimal drying time, energy consumption, and color parameters was found to be at 180 W microwave power and 70 °C.
BENFOTHIAMINE ADMINISTRATION IN PATIENTS WITH DILATED CARDIOMYOPATHY AND ADVANCED HEART FAILURE WITH CHRONIC DIURETIC TREATMENT
(STUDIA UBB CHEMIA. Published by Babeş-Bolyai University, 2017-03-30) Dana-Adriana ILUȚIU-VARVARA; Dan RĂDULESCU; Valer Ioan DONCA
It is well known that long term administration of high dose loop diuretics in patients with heart failure, may in some cases aggravate the cardiac failure symptoms. Part of this effect may be due to thiamine depletion secondary to diuretics use. The aim of our present study was to assess whether administration of benfothiamine in patients with advanced congestive cardiac failure treated on long term with high dose loop diuretics, can prevent the alteration of heart failure.
SEASONAL EVOLUTION AND DEPTH VARIABILITY OF HEAVY METAL CONCENTRATIONS IN THE WATER OF FIRIZA-STRÎMTORI LAKE, NW OF ROMANIA
(STUDIA UBB CHEMIA. Published by Babeş-Bolyai University, 2017-03-30) Thomas DIPPONG; Cristina MIHALI; Firuța GOGA; Elena CICAL
The paper follows the spatial variability and seasonal evolution of the heavy metal content of the Firiza-Strîmtori Reservoir that is the main source of drinking water for Baia Mare city located in the northwestern part of Romania. Water samples were collected from 10 sampling points located along the median line of the lake at different depths (at surface, at 5 m, 10 m, 15 m and 20 m). The experiments were carried out in the winter, spring, summer and autumn of 2015. We determined the concentration – depth profiles, both for the heavy metals iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb) and also for sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg). We determined the concentrations of heavy metals by atomic absorption spectrometry. We found that concentrations of heavy metals increase with depth. Generally, the concentrations of heavy metals are within the legal limits for the water used as drinking water sources. Mathematical models with high correlation coefficients were obtained in the case of heavy metal concentrations depending on depth and also for the seasonality of heavy metals upload.