EXAMPLES OF LCA METHODOLOGY IMPLEMENTATION IN STEEL INDUSTRY

Steel industry kept pace with actual trends for environmental protection in many ways – through different technological improvements considering environment protection, important share of recycling in the steel production, design of so called “eco-steels”, materials designed according to recent environmental directives and legislatives, etc. In the frame of steel production monitoring, LCA methodology is very important for obtaining an accurate environmental picture of a process, due to the fact that the process should be evaluated over its entire life cycle. A number of tools and methodologies have been developed in recent years to assess the potential environmental impacts associated with a product, process or activity during its entire life cycle. The examples of Life Cycle Assessment (LCA) are used by large steel industrial companies as potentially helpful tool for improving the production processes, efficiency of resource utilization and significantly reduction of waste generation and emissions are presented in this paper

Kalorimetrijsko ispitivanje tekućih Ga-Me (Sn, Zn) legura Oelsenovom metodom

The results of calorimetric investigation of binary, liquid Ga-Me (Sn, Zn) alloys are presented in this paper. According to constructed space enthalpy diagram and enthalpy isotherm diagram, activities, activity coefficients and other partial and integral molar quantities were determined at different temperatures. Also, comparison was made with existing literature data

Electrical Characterization and Impedance Response of Lanthanum Doped Barium Titanate Ceramics

The dielectric permittivity and dissipation factor of La-doped and undoped BaTiO3 were investigated as a function of frequency and temperature. The impedance response was used to study the electrical properties of La-doped BaTiO3 over the temperature range from room temperature (RT) to 350 degrees C. La-doped and undoped BaTiO3, obtained by a modified Pechini method, were sintered in air at 1300 degrees C for 2 and 16 hours. The impedance spectra were analyzed in terms of equivalent circuits involving resistors, capacitors and constant phase elements (CPE). The most suitable electrical circuit for the interpretation of experimental results is found to be the equivalent circuit consisting of resistors and CPE elements which replace the capacitor elements. The contribution of grain boundary resistance to the total resistance of a system is remarkable at low temperature. Dielectric permittivity of doped BaTiO3 was in the range of 8000 to 12000 at 1 kHz and the dissipation factor was less than 1%

Dilatometer Investigations of Reactive Sintering of Zinc Titanate Ceramics

Poster presented at the The Sixth Yugoslav Materials Research Society Conference - YUCOMAT 2004, Herceg Novi, Crna Gora, September 13-17, 2004

Supplementary data for article: Mišić, D.; Šiler, B.; Gašić, U.; Avramov, S.; Živković, S.; Živković, J. N.; Milutinović, M.; Tešić, Ž. Simultaneous UHPLC/DAD/(+/-)HESI-MS/MS Analysis of Phenolic Acids and Nepetalactones in Methanol Extracts of Nepeta Species: A Possible Application in Chemotaxonomic Studies. Phytochemical Analysis 2015, 26 (1), 72–85. https://doi.org/10.1002/pca.2538

Supporting information for: [https://doi.org/10.1002/pca.2538]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1663

Chemical risk factors responsible for the formation of wedge-shaped lesions

Introduction: Non-carious tooth substances loss pose a major health problem of a modern man. The literature often collectively describes all non-carious lesions and is therefore difficult to compare results obtained by different authors. Chemical factors are one of the predisposing factors responsible for the formation of wedge-shaped erosions. Aim: Examination of chemical risk factors as one of the predisposing causes responsible for the formation of wedge-shaped lesions. Method: We examined 62 patients with wedge-shaped erosions (mean age 45.52 ± 12.03 years, 58.1% of men) and 60 patients without erosions in the control group (mean age 34.40 ± 9.28 years, 60% men) . The entire examination was completed by using a questionnaire at the Dental Clinic of the University of Pristina - Kosovska Mitrovica. salivary pH was measured by the pH meter. Results: The results show that the wedge-shaped lesions often occur equally in both men and women. Considerably often it might appear in older people but can also occur in teenagers. Patients with wedge-shaped erosion have increased acidity of saliva, a heightened sense of acid in the mouth and consume a lot more carbonated drinks compared to patients without erosions. Conclusion: Wedge-shaped lesions are more common in people older than 40 years. Taking into account the results obtained in this study it can be concluded that the chemical risk factors truly fall within the predisposing factors that may be responsible for the creation of wedge-shaped erosions

Thermal analysis and kinetics of the chalcopyrite-pyrite concentrate oxidation process

The paper presents the results of experimental investigation of the chalcopyrite-pyrite concentrate oxidation in the air. Characterisation of the initial sample and oxidation products was done by ICP-AES, XRD, EDXRF methods. Phase stability diagrams were constructed for Cu-Fe-S-O system at 25, 450, 650 and 900 °C. Equilibrium composition of the charge for the optimal oxidation process was calculated. DTA-TG analysis was used for monitoring the oxidation process. Kinetic parameters in non-isothermal conditions were determined, based on Kissinger and Ozawa methods.Values of activation energies showed that all stages of the oxidation process occur in the kinetic field

Synthesis of BaTiO3 from a mechanically activated BaCO3-TiO2 system

In this article the solid state reaction of BaTiO3 formation from a mechanically activated BaCO3-TiO2 system has been investigated. An equimolar mixture of BaCO3 and TiO2 powders was activated in a planetary ball mill in a continual regime for 0, 30 and 90 min, pressed and thermally treated up to 1200°C. The effect of the milling and firing regime on the phase formation was investigated by the X-ray diffraction (XRD) method and differential thermal analysis (DTA). Deconvolution of the experimental DTA curve corresponding to the BaTiO3 synthesis process has been performed. The influence of the activation time on the change of characteristic temperature for each elementary step in the complete solid-state reaction of BaTiO3 formation, was analyzed. These results were correlated with the ones obtained by SEM characterization and by XRD analysis.U ovome radu je analiziran uticaj mehaničke aktivacije sistema BaCO3- TiO2 na formiranje BaTiO3. Ekvimolarne smeše praha BaCO3 i TiO2 su aktivirane u planetarnom mlinu u kontinualnom režimu tokom 0, 30 i 90 min. Uzorci su zatim presovani i termički tretirani do 1200oC. Efekat mlevenja i zagrevanja na promene faza je analiziran primenom rendgenske fazne analize i diferencijalne termijske analize. Izvršena je dekonvolucija eksperimentalno dobijene DTA krive koja odgovara procesu sinteze BaTiO3, kao i analiza uticaja vremena aktivacije na promene karakteristične temperature za svaki pojedinačni elementarni proces tokom sinteze barijum titanata. Ovi rezultati su korelisani sa rezultatima dobijenim SEM i XRD analizom

Tyrosinase Inhibitory and Antioxidant Activity of Wild Prunus spinosa L. Fruit Extracts as Natural Source of Bioactive Compounds

In recent years, naturally derived tyrosinase inhibitors and antioxidants have become very important, since the synthetic ones are related with several side effects. As wild fruits are rich source of bioactive compounds, this study focused on the examination of Prunus spinosa L. (blackthorn) fruit extracts, widely distributed in our country. However, blackthorn extracts are not enough investigated, and there are only a few published works. Extraction efficiency of P. spinosa ultrasonic fruit extracts obtained by using different solvents (methanol, 70% (v/v) ethanol, 45% (w/w) propylene glycol and water) was evaluated, regarding polyphenolic profile, tyrosinase inhibitory and antioxidant activity. Results suggested that extracts with 45% propylene glycol and water were particularly rich in polyphenolic compounds (especially phenols, flavonoids and anthocyanins). The highest extraction yield was for 45% propylene glycol extract. This extract showed higher tyrosinase inhibitory and antioxidant activity compared to others, while the methanolic extracts had the highest chelating capacity. Therefore, P. spinosa fruit extracts, especially extracts obtained by ultrasonic extraction with 45% propylene glycol, have a great potential to be incorporated in some pharmaceutical formulations for obtaining tyrosinase inhibitory and antioxidant effects