190 research outputs found
Physical properties and the distribution of heavy metals in soils of the urban area of Novi Sad
Uzorci zemljišta iz povšinskog sloja dubine 0 - 10 cm prikupljeni su sa 121 lokacije na gradskom području Novog Sada. Ispitivano područje obuhvatilo je površinu (4 x 5)km2, koja je podeljena na mrežna polja veličine (400 x 400) m2 i u svakom polju uzet je po jedan uzorak. Za 121 uzorak gradskog zemljišta Novog Sada ispitana su fizičko-hemijska svojstva zemljišta, ukupni i pristupačni sadržaj metala (As, Co, Cr, Cu, Mn, Ni, Pb, Zn) i njihova prostorna raspodela. Konturne mape prostorne raspodele metala u zemljištu dobijene su korišćenjem interpolacijske metode običnog kriginga. Za pojedine uzorke izvršeno je razdvajanje čestica po veličinama frakcionisanjem u vodi pomoću sita različitih veličina i identifikovani su minerali prisutni u frakciji prah + glina. Aktivnosti radionuklida „unsupported” 210Pb i 137Cs određene su za jedan deo uzoraka zemljišta u Novom Sadu i za uzorke zemljišta pored fabrike akumulatora u Somboru. Ispitana je i vertikalna distribucija stabilnog i radioaktivnog Pb u zemljištu. Na 14 lokacija u Novom Sadu prikupljeno je 35 uzoraka snega direktno sa asfaltnih puteva i sa zemljanih površina u okolini puteva i na pešačkim ostrvima. Raspodela čestica po veličinama i ukupne koncentracije metala (Al, Ca, Cu, Fe, K, Na, Mn, Ni, Pb, Zn) određene su analizom filtriranih uzoraka, a za 4 uzorka ispitana je morfologija čestica i urađena semikvantitativna analiza čestica u suvoj materiji. Prilikom obrade rezultata merenja primenjene su metode deskriptivne statistike i multivarijacione statističke analize u cilju identifikacije izvora zagađenja i određivanja povezanosti između samih metala i drugih parametara.A total of 121 surface soil samples were collected across the central part of Novi Sad covering a surface area (4 km x 5 km). The physicochemical properties, pseudo total and available metal concentrations (As, Co, Cr, Cu, Mn, Ni, Pb, and Zn) were determined. Contour maps of spatial distribution of the investigated metals were obtained using ordinary kriging interpolation method. Separation of different particle size fractions by wet sieving and identification of minerals in the clay and silt fraction for some soil samples were performed. Specific activities of radionuclides “unsupported” 210Pb and 137Cs were measured in forty soil samples collected in urban area of Novi Sad and industrial area of Sombor (near a battery manufacturer). Vertical distribution of stable and radioactive Pb for two samples from the industrial soil was examined. Thirty five snow samples were collected at fourteen locations near crossroads in Novi Sad. The samples were taken directly from the road surface and from the ground surface in the vicinity of roads and on pedestrian islands. Particle size distribution and total concentration of the metals (Al, Ca, Cu, Fe, K, Na, Mn, Ni, Pb, Zn) were determined for filtered samples. Semi-quantitative analysis of the particles was conducted and morphology of the particles was examined for dry matter of four snow samples. Methods of descriptive and multivariate statistics and geostatistics were carried out for the analysis and interpretation of the data
Physical properties and the distribution of heavy metals in soils of the urban area of Novi Sad
Uzorci zemljišta iz povšinskog sloja dubine 0 - 10 cm prikupljeni su sa 121 lokacije na gradskom području Novog Sada. Ispitivano područje obuhvatilo je površinu (4 x 5)km2, koja je podeljena na mrežna polja veličine (400 x 400) m2 i u svakom polju uzet je po jedan uzorak. Za 121 uzorak gradskog zemljišta Novog Sada ispitana su fizičko-hemijska svojstva zemljišta, ukupni i pristupačni sadržaj metala (As, Co, Cr, Cu, Mn, Ni, Pb, Zn) i njihova prostorna raspodela. Konturne mape prostorne raspodele metala u zemljištu dobijene su korišćenjem interpolacijske metode običnog kriginga. Za pojedine uzorke izvršeno je razdvajanje čestica po veličinama frakcionisanjem u vodi pomoću sita različitih veličina i identifikovani su minerali prisutni u frakciji prah + glina. Aktivnosti radionuklida „unsupported” 210Pb i 137Cs određene su za jedan deo uzoraka zemljišta u Novom Sadu i za uzorke zemljišta pored fabrike akumulatora u Somboru. Ispitana je i vertikalna distribucija stabilnog i radioaktivnog Pb u zemljištu. Na 14 lokacija u Novom Sadu prikupljeno je 35 uzoraka snega direktno sa asfaltnih puteva i sa zemljanih površina u okolini puteva i na pešačkim ostrvima. Raspodela čestica po veličinama i ukupne koncentracije metala (Al, Ca, Cu, Fe, K, Na, Mn, Ni, Pb, Zn) određene su analizom filtriranih uzoraka, a za 4 uzorka ispitana je morfologija čestica i urađena semikvantitativna analiza čestica u suvoj materiji. Prilikom obrade rezultata merenja primenjene su metode deskriptivne statistike i multivarijacione statističke analize u cilju identifikacije izvora zagađenja i određivanja povezanosti između samih metala i drugih parametara.A total of 121 surface soil samples were collected across the central part of Novi Sad covering a surface area (4 km x 5 km). The physicochemical properties, pseudo total and available metal concentrations (As, Co, Cr, Cu, Mn, Ni, Pb, and Zn) were determined. Contour maps of spatial distribution of the investigated metals were obtained using ordinary kriging interpolation method. Separation of different particle size fractions by wet sieving and identification of minerals in the clay and silt fraction for some soil samples were performed. Specific activities of radionuclides “unsupported” 210Pb and 137Cs were measured in forty soil samples collected in urban area of Novi Sad and industrial area of Sombor (near a battery manufacturer). Vertical distribution of stable and radioactive Pb for two samples from the industrial soil was examined. Thirty five snow samples were collected at fourteen locations near crossroads in Novi Sad. The samples were taken directly from the road surface and from the ground surface in the vicinity of roads and on pedestrian islands. Particle size distribution and total concentration of the metals (Al, Ca, Cu, Fe, K, Na, Mn, Ni, Pb, Zn) were determined for filtered samples. Semi-quantitative analysis of the particles was conducted and morphology of the particles was examined for dry matter of four snow samples. Methods of descriptive and multivariate statistics and geostatistics were carried out for the analysis and interpretation of the data
The use of electromagnetic field in designing the high quality Al alloys for hot forging process
This work presents a way to obtain the better quality of EN AW 7075 aluminum high-strength alloy by application of electromagnetic field (EMF) during the casting process. In this way, the uniform fine-grained microstructure, and hence the better mechanical properties of the alloy can be achieved. The microstructure and mechanical characterization for samples obtained with and without EMF were performed. The application of numerical simulation for hot forging process, using appropriate software, is efficient and highly useful tool for problem prediction in industrial production, reducing the time and costs in the process of development of new products. The input data of high strength Al-alloy EN AW-7075 is used for simulation because it enables the development of parts with complex dimensions and shape. http://dx.doi.org/10.5937/metmateng1404247
Analiza citohistoloških faktora koji doprinose pojavi nepravilnih krvarenja, bola i febrilnosti kod pacijenatkinja sa miomima uterusa
Rezultati naše studije pokazali su da nije uočena statistički značajna razlika u histološkom tipu mioma između ispitanica sa iregularnim krvarenjem i ispitanica bez simptoma i sa bolom i inflamacijom. Ovakav rezultat sugeriše da histološki tip mioma ne utiče na kliničku sliku pacijentkinje. U obe analizirane grupe u ovoj studiji najzastupljenije su bile ispitanice sa miomima celularnog tipa i miomima neurolinoma-like tipa.
Statistički značajna razlika nije uočena ni u ekspresiji α- glatkomišićnog aktina između ispitanica sa iregularnim krvarenjima i kontrolne grupe ispitanica. I u grupi sa iregularni krvarenjima i u grupi sa bolom i inflamacijom i asimptomatskim miomima, najmanje ispitanica imalo je ekspresiju α- glatkomišićnog aktina manju od 35% (+), a najviše je bilo ispitanica sa ekspresijom do 100% (+++). Ovakav rezultat sugeriše da dominantu ćelijsku populaciju u tkivu mioma, bez obzira histološki tip, čine glatke mišićne ćelije različitog fenotipskog statusa, među kojima dominiraju glatke mišićne ćelije kontraktilnog fenotipa, uz prisutan jedan broj glatkih miocita sintetskog fenotipa organizovan u vidu ostrvaca između njih.
Između analiziranih grupa nije uočena statistički značajna razlika ni u ekspresiji CD34. U obe grupe najviše je bilo ispitanica sa ekspresijom CD34 opisanom sa dva (do 35%) i jednim (do 75%) plusom a najmanje sa ekspresijom opisanom sa tri plusa. Kako je CD34 antigen koji se između ostalog eksprimira na površini tkivnih fibroblasta, ovakav rezultat sugeriše da bez obzira na histološki tip mioma tkivni fibroblasti čine manju ćelijsku populaciju u tkivu u odnosu na populaciju glatkih mišićnih ćelija
On the properties of hot forged Ti-6Al-4V alloy aimed for surgical implants
The investigation here is aimed to examine the structural and mechanical changes that might have occurred during the hot forging process, a process to obtain a surgical hip implant, and the subsequent heat treatment. Microstructural characterization, morphological and semi-quantitative chemical analyses have been accomplished using an optical and scanning electron microscope. Chemical analyses of all surfaces obtained by the dotted method in all analyzed samples have shown the approximate equal content of aluminum, titanium, vanadium, iron, and silicon. Tensile testing and measurements were following obtained microstructure, showing the uniformity of microstructure and properties along the forging part, as well as over its cross section. All tests proved that hot forging could be a suitable procedure for surgical implants processing
Emissions of total volatile organic compounds during the digital printing process
The impact of the type of digital machine on increasing of total volatile organic compounds (TVOCs) in the ambient air of the digital printing office was analysed in this study. For that purpose, the TVOCs concentrations in gas samples were measured by mobile gas chromatograph Voyager-Photovac. The cumulative concentrations values of TVOCs for the single-color digital machine were in the range from 0.56 to 5.90 ppm and almost 4 and 25 times below compared to the same values for the four-color digital machine (14.01 - 24.84 ppm). The obtained results could be useful for the future risk assessment of indoor exposure of TVOCs, and for the creation of printing indoor air quality guidelines of the Republic of Serbia
The use of electromagnetic field in designing the high quality Al alloys for hot forging process
This work presents a way to obtain the better quality of EN AW 7075 aluminum high-strength alloy by application of electromagnetic field (EMF) during the casting process. In this way, the uniform fine-grained microstructure, and hence the better mechanical properties of the alloy can be achieved. The microstructure and mechanical characterization for samples obtained with and without EMF were performed. The application of numerical simulation for hot forging process, using appropriate software, is efficient and highly useful tool for problem prediction in industrial production, reducing the time and costs in the process of development of new products. The input data of high strength Al-alloy EN AW-7075 is used for simulation because it enables the development of parts with complex dimensions and shape. http://dx.doi.org/10.5937/metmateng1404247
UNSUCCESSFUL PRIMARY PCI FOR POSTPARTAL DISSECTION OF ALL THREE MAJOR CORONARY ARTERIES
Coronary artery dissection is rare but very dangerous condition which can result in myocardial infarction. It mostly occurs in young postpartum women. The left anterior descending artery is affected in 75% of cases and in some extremely rare cases dissection may include all three coronary arteries. Treatment guides are still not consistent. While some authors recommend medical treatment other recommend surgical one. Case report. We present a 36-year-old female patient who was admitted to our hospital with intermittent chest pain and dyspnea that occurred two hours before admission. After premedication with Aspirin 300 mg per os, Clopidogrel 300 mg per os and Enoxaparin 30 mg iv, the pain disappeared. Chest pain was repeated after five days. Coronary angiography revealed spiral dissection in medial segment of LAD. After PCI attempt, dissection progressed and ended fatal. Pathological finding was intimal dissection of the coronary arteries with loss of some parts of internal elastic lamina. It is interesting that in the literature there is no consistent opinion about therapeutic approach to SDCA and we hope that this case report will contribute to elucidating the problem
The heavy metals in the processing screen printing inks
The contents of heavy metals were analyzed in the two types (solvent-based and water-based) of processing screen printing inks. Mass concentrations of heavy metals (copper, iron, zinc, manganese, chromium, nickel, cadmium, and lead) were determined in the tested screen inks by combining the gravimetric method and atomic absorption spectroscopy. The results indicated that the measured mass concentration of copper (2049.9 mg kg-1 ) in solvent-based cyan ink is 2.4 times higher than in water-based cyan. Other detected metals show higher concentration values with water-based processing inks
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