Response surface methodology (RSM) and central composite design have been applied to describe and optimize photocatalytic degradation of azo pyridone dye using TiO2, H2O2, and simulated sun light. ...The mutual interactions between three independent variables, viz. H2O2 concentration, irradiation time, and TiO2 content were obtained. The results revealed that the most influential variables under selected reaction conditions were irradiation time and TiO2 content. The optimized conditions for the photocatalytic degradation of azo pyridone dye were as follows: H2O2 concentration: 130.5 mg/L, irradiation time: 54.8 min, and TiO2 content: 2.48 g/L. Under these conditions, the maximum decolorization efficiency of 96.43% was achieved. This experimental value was in good agreement with the predicted one, which proved the validity of the model. Operation cost analysis indicated that irradiation time had the major influence on total process cost. The RSM based on the central composite design was shown to be a successful technique for the optimization of the decolorization efficiency of azo pyridone dye and can be very helpful in improving the process economic feasibility. TOC analysis showed that the dye could be effectively mineralized during photocatalytic degradation.
The use of satellite images in the field of agriculture Grujić, Nastasija; Golubović, Marina; Jovanović, Dušan
Zbornik radova Departmana za geografiju, turizam i hotelijerstvo,
2018, Letnik:
2018, Številka:
47-2
Journal Article
Recenzirano
Odprti dostop
The use of remote sensing in the field of agriculture is very diverse. It includes detection of the amount of chlorophyll in crops, the amount of water, the detection of pests, the creation of maps ...for selective spraying and feeding, etc. In this work, different vegetation indices were applied on satellite imageries obtained from platforms: Sentinel2, Landsat8, RapidEye, and PlanetScope, in order to detect trends in the vegetation of different cultures. RapidEye and PlanetScope imageries were used in order to detect nitrogen variation for agricultural parcels in the area of the municipality of Becej. In this case indices NDVI, NDRE, and MSAVI2 are applied for cultures: corn, sunflower, wheat, sugar beet, and soybean. Sentinel2 and Landsat8 imageries were used for the analysis of the orchard near Celarevo in the municipality of Backa Palanka and analysis of agricultural parcel with a predominantly agricultural crop near Stapar in the municipality of Sombor. The detection of an area with health and non-health vegetation was made, as well as a comparison of the obtained vegetation trends between two platforms. The applied indices were: NDVI, TNDVI, GNDVI, EVI2, WDRVI, and GLI.
The effects of silver content on the structure, morphology, texture, H
2-adsorption capacity and catalytic performance in soybean oil hydrogenation of Mg-Ni/diatomite materials have been ...investigated. The most promising candidate is the catalyst with higher silver content (Ag/Ni
=
0.1, SiO
2/Ni
=
1.07 and Mg/Ni
=
0.1) producing hydrogenated derivatives of lower of solid fat, stearic acid and detrimental
trans fatty acids.
Stearic acid (empty symbols) and TFA (
trans fatty acids – filled symbols) profiles
vs time.
▪
Silver modified Mg-Ni/diatomite materials with ratios of SiO
2/Ni
=
1.07 and Mg/Ni
=
0.1, differing in Ag content (Ag/Ni
=
0.025 and 0.1) were prepared by the precipitation–deposition method. The effects of silver presence and content on the structure, morphology, texture and H
2-adsorption capacity of the obtained precursors were studied by X-ray diffraction, scanning electron microscopy, Hg-porosimetry and H
2-chemisorption techniques. The catalytic performance of the corresponding catalysts in the soybean oil hydrogenation was investigated. The increase of the silver loading resulted in the development of macroporosity and increase in the total sample porosity. The decrease of both H
2-adsorption capacity and hydrogenation activity are related to the metallic silver covering and blocking effects on the Ni
2+ species, thus hampering the access of hydrogen. The decrease of hydrogenation activity and favorable limiting of
cis–
trans isomerization on the silver modified catalyst are explained by Horiuti–Polanyi mechanism based on the assumption that hydrogenation and isomerization proceed at the same active metallic nickel sites
via half-hydrogenated intermediates.
It was shown that the adjustment of the catalyst composition by changing the content of silver modifier offers the possibility to control the total amount of solid fat content, stearic acid and detrimental
trans fatty acids in the hydrogenated derivatives. The catalyst with higher silver content is proposed as a promising candidate for selective edible oil hydrogenation catalyst.
Despite the fact that treatment of liver injuries has dramatically evolved, severe liver traumas in polytraumatic patients still have a significant morbidity and mortality.
The purpose of this study ...was to determine the options for surgical management of severe liver trauma as well as the outcome.
In this retrospective study 70 polytraumatic patients with severe (American Association for the Surgery of Trauma AAST grade III-V) blunt liver injuries were operated on at the Clinic for Emergency Surgery.
Mean age of patients was 48.26±16.80 years; 82.8% of patients were male. Road traffic accident was the leading cause of trauma, seen in 63 patients (90.0%). Primary repair was performed in 36 patients (51.4%), while damage control with perihepatic packing was done in 34 (48.6%). Complications related to the liver occurred in 14 patients (20.0%). Liver related mortality was 17.1%. Non-survivors had a significantly higher AAST grade (p=0.0001), higher aspartate aminotransferase level (p=0.01), lower hemoglobin level (p=0.0001), associated brain injury (p=0.0001), perioperative complications (p=0.001) and higher transfusion score (p=0.0001). The most common cause of mortality in the "early period" was uncontrolled bleeding, in the "late period" mortality was caused by sepsis and acute respiratory distress syndrome.
Patients with high-grade liver trauma who present with hemorrhagic shock and associated severe injury should be managed operatively. Mortality from liver trauma is high for patients with higher AAST grade of injury, associated brain injury and massive transfusion score.
The aim of this study was to find a low cost, easy to synthesize and efficient adsorbent for the simultaneous adsorption of both organic and inorganic pollutants (including textile dyes, toxic metals ...etc.). The stalling material, domestic bentonite clay from Bogovina was modified with amounts of hexadecyltrimethylaminonium cations corresponding to 0.5 and 1.0 times of the value of the cation exchange capacity value. The organobentouites were tested as adsorbents in a three-dye-containing solution, a three-component solution of Pb super(2-). Cd super(2-) and Ni super(2+) and a hexa-component solution containing all investigated dyes and toxic metal cations. The used adsorbents showed the highest affinity toward Acid Yellow 99 and Ni super(2+) ions. Dye adsorption was enhanced in the presence of toxic metal cations, while the adsoiption of all toxic cations from the hexa-component solution was lower than from the three-component solution containing only toxic cations. The synthesized hexadecyltrimethylammonium bentonite could be regarded as an efficient multifunctional adsorbent for the investigated type of water pollutants.
Toluene Degradation in Water Using AlFe-Pillared Clay Catalysts Predrag BANKOVIC~ Aleksandra MILUTINOVIC-NIKOLIC Zorica MOJOVIC Aleksandra ROSIC Zeljko CUPIC Davor LONCAREVIC Dusan JOVANOVIC
Chinese journal of catalysis,
2009, 2009-1-00, Letnik:
30, Številka:
1
Journal Article
Recenzirano
The catalytic wet peroxide oxidation （CWPO） of toluene on two bentonite-based AlFe-pillared clays （PILCs） with different iron contents was investigated. The PILCs were obtained using bentonite clay ...from Bogovina, Serbia. The change in chemical and phase composition and textural properties of the starting clay and synthesized catalysts was monitored using X-ray diffraction, inductively coupled plasma optical emission spectrometry, UV-Vis diffuse reflectance spectrometry, and physisorption of nitrogen. The catalytic performance was examined using gas chromatography. The Na-exchange process lowered the （001） smectite basal plane spacing, but the clay retained its swelling properties, while the pillaring process increased it. The surface areas of both synthesized pillared clays increased to similar values although their Fe content was different. At 37℃ , both catalysts show significant toluene degradation, with the one richer in Fe having higher efficiency. The leaching of the active cations during reaction was negligible, and the catalysts were stable. AlFe-pillared clay catalysts can be used in CWPO for the elimination of BTEX compounds from plant effluent streams.
Photocatalytic degradation of synthesized azo pyridone dye (5-(4-sulpho phenylazo)-6-hydroxy-4-methyl-3-cyano-2-pyridone), in aqueous solutions by simulated sunlight in the presence of commercial ...TiO₂, Aeroxide P25, was studied. The reaction kinetics analysis showed that photodegradation exhibits pseudo first-order kinetics according to Langmuir-Hinshelwood model. The effects of various process parameters on the photocatalytic degradation were investigated. The optimal catalyst content and pH were determined. A decrease in the reaction rate was observed upon the increase of the initial dye concentration. Degradation of the dye was enhanced by hydrogen peroxide, but it was inhibited by ethanol. The influence of temperature was studied, and the energy of activation was determined. According to total organic carbon (TOC) analysis, 54% of TOC remained when 100% of the dye was decolorized. Although the intermediates were not determined in this study, the TOC results clearly indicate their presence during the reaction. In addition, photocatalytic degradation of simulated dyehouse effluents, containing tested azo pyridone dye and associated auxiliary chemicals was investigated.
Bone scintigraphy is well-known method for the detection of neoplastic lesions with a high sensitivity and, at the same time, a lower specificity. On the other hand magnetic resonance imaging (MRI) ...is previously established noninvasive imaging method regar ding its diagnostic specificity. The aim of this study was to determine the possibilities and to correlate two different diagnostic methods--bone scintigraphy and MRI in the detection of bone metastasis in the spine and pelvic bones.
A total of 123 patients who underwent both bone scintigraphy and spine and pelvic MRI on 1.5 T MR imager were enrolled in this study. Scans were subsequently analyzed in total and divided in regions of interest (cervical, upper, middle and lower thoracic, upper and lower lumbar and pelvic region, which includes sacral spinal segment); afterwards the total number of 585 mat ching regions were compared and statistically analyzed.
The statistical analysis demonstrated significant correlation between the findings of both methods in total. Divided by regions of interest, significant degrees of correlation were demonstrated in all of them, except in the cervical spine region where the r-value was in the range of low correlation.
Having a high mutual correlation, bone scintigraphy and MRI are to be considered as the complementary diagnostic methods in the detection of bone metastases. Still, increased diagnostic potential of MRI may highlights negative bone scintigraphy findings in the patients with solitary metastatic lesions or diffuse vertebral infiltration. Advances in the bone scintigraphy (single photon emission tomography--SPECT, SPECT-computed tomography--SPECT-CT) and MRI (whole body MRI, diffusion MRI), make it possible the diagnostic potential of both methods will result in a further improvement in bone metastasis detection.
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