Eggers R.,TU Hamburg - Harburg |
Jaeger P.,TU Hamburg - Harburg |
Heinrich H.,TU Hamburg - Harburg |
Roj E.,Fertilizers Research Institute
Journal of Supercritical Fluids | Year: 2010
Swelling of plant material belonging to several plant families and the influence of swelling on supercritical fluid extraction process were investigated in this study. While swelling of Lamiaceae family species as well as hop cones and pellets occurred during the exposure of plant material to supercritical carbon dioxide, swelling of valerian root and ginger rhizome happened after the decompression step. Optimal pretreatment of herbaceous matrix which will enable commencement of continuous extraction from already swollen plant material was defined on the basis of swelling test results. Experimental results were modeled and energy savings due to the optimal processing on the laboratory scale were calculated. Sorption of carbon dioxide into the hop pellet was measured and the diffusion coefficient in the solid phase was determined. Obtained results indicated that the effective diffusion coefficient in the hop pellet was increased by one order of magnitude due to swelling. © 2009 Elsevier B.V. All rights reserved.
Labuzek K.,University of Silesia |
Gorki K.,University of Silesia |
Jaroszek H.,Fertilizers Research Institute |
Jarzabek K.,University of Silesia |
And 2 more authors.
CNS and Neurological Disorders - Drug Targets | Year: 2013
The blood-brain barrier significantly impedes treatment of central nervous system disorders by preventing drug entry into the brain. Several strategies have been developed to overcome this problem, but progress has been hampered due to a lack of efficacious drug delivery systems (DDS). Now, owing to DDS, therapeutic compounds can be transported to the site of action and accumulate there. This modern approach allows one to decrease the required dose of drug and, therefore, minimize toxicity and side effects. Also, treatment efficiency is increased. Highly organized nanostructures made of biological, polymeric or carbon-based materials are promising carriers in drug delivery to the brain, due to their unique and easily tailorable properties. The drug can be either attached to or entrapped in a carrier. To achieve greater site specificity and selectivity, DDS can be also modified with suitable ligands, providing identification of the molecular site of action. This review illustrates recent advances in using highly-organized structures: dendrimers, fullerenes, liposomes, micelles, nanogels, nanoparticles and nanotubes for this purpose. We also discuss advantages and limitations of each system. © 2013 Bentham Science Publishers.
Wojcik P.,Research Institute of Horticulture |
Borowik M.,Fertilizers Research Institute
Journal of Plant Nutrition | Year: 2013
The aim of the study was to examine effect of preharvest sprays of a mixture of calcium (Ca) formate, Ca-acetate, Ca-chloride (CaCl2) and Ca-nitrate [Ca(NO3)2] on quality and apple storability. The experiment was conducted during 2008-2009 at the Experimental Station of the Research Institute of Horticulture in Skierniewice, Poland, on mature 'Jonagold' apple trees/M.26, planted at a moderate density on a coarse-textured soil with low status of organic matter and abundant in exchangeable Ca. Apple trees were sprayed with Ca, 7 times per season, at 2-week intervals, starting 3 weeks after blooming. In the spray treatments a mixture of Ca-formate, Ca-acetate, CaCl2 and Ca(NO3)2 (as Insol Wap fertilizer), CaCl2 or Ca(NO3)2 were used at rates of 7.3 kg Ca, 11.8 kg Ca, and 9.9 kg Ca ha-1 per season, respectively. The trees sprayed with water were treated as the control. The results showed that Ca sprays caused no leaf and fruit injury. Calcium spray measures did not affect yield, mean fruit weight, and soluble solids concentration (SSC), titratable acidity and starch index of fruit at harvest. However, at harvest apples sprayed with Ca contained more this nutrient and were firmer than those of the control plots. After storage apples sprayed with Ca had more acids, and were firmer and less liable to bitter pit than the control fruit. Calcium sprays did not affect SSC of fruit after storage but reduced postharvest decay of fruit caused by Peziculla spp. and Penicillium expansum fungi. Apples sprayed with Insol Wap material were the least affected by the above pathogens. It is concluded that in apple orchards preharvest sprays of a mixture of Ca-formate, Ca-acetate, CaCl2 and Ca(NO3)2, containing 10% Ca (w/w) with ca. 50% in an organic form, can be the alternative to sprays of CaCl2 or Ca(NO3)2. © 2013 Copyright Taylor and Francis Group, LLC.
Cichy B.,Fertilizers Research Institute |
Kuzdzal E.,Fertilizers Research Institute
Industrial and Engineering Chemistry Research | Year: 2012
The kinetics of the melamine phosphate precipitation reaction under stable mixing conditions and at constant temperature were described along with the morphology of the crystals obtained. The kinetics of the reaction between melamine and phosphoric acid was described using a model of crystallization which included a stage of rapid dissolution of solid melamine dispersed in water in phosphoric acid, followed by nucleation and growth of sparingly soluble crystals of melamine phosphate. Experimental results have confirmed the assumptions made. The size and shape of the obtained melamine phosphate particles is important for the size and shape of the product of the second reaction - melamine polyphosphate. This allows for a certain scope of control over the process of shaping the particles of plastics filler - melamine polyphosphate. © 2012 American Chemical Society.
Skalska K.,Technical University of Lodz |
Miller J.S.,Technical University of Lodz |
Wilk M.,Fertilizers Research Institute |
Ledakowicz S.,Technical University of Lodz
Ozone: Science and Engineering | Year: 2012
Attempts to develop new technologies of reduction of NOx emission are still carried out all around the world. However, most of them as literature survey suggests is focused on NOx emission control from power plants and mobile vehicles. Fewer investigations are conducted on the NOx emission abatement from the chemical industry. One of the relatively new approaches is the application of ozone injection into exhaust gas stream followed by an absorption process. Ozone is used to transform NOx to higher nitrogen oxides that are more soluble in water, and therefore the higher yield of nitric acid is expected. The main objective of this article is to present results of our studies in which the effectiveness of the ozonation process, as well as the dependence of the conversion rate and the selectivities of NO ozonation into NO2, N2O5 and HNO3 on the residence time of reagents in the reactor space were studied. Results of laboratory investigations were confirmed during ozonation experiments with real exhaust gases from a nitric acid pilot plant in Fertilizers Research Institute in Pulawy, Poland. © 2012 Copyright 2012 International Ozone Association.
Szustakiewicz K.,Wroclaw University of Technology |
Cichy B.,Fertilizers Research Institute |
Gazinska M.,Wroclaw University of Technology |
Piglowski J.,Wroclaw University of Technology
Journal of Reinforced Plastics and Composites | Year: 2013
The article reports on flammability, thermal, and mechanical properties of bimodal high-density polyethylene/clay nanocomposites modified with ammonium polyphosphate or melamine polyphosphate (MPP) flame retardants. Two types of clays were used as fillers for the composites - the first one was standard montmorillonite modified with quaternary ammonium salt (ZR2), and the second one was montmorillonite modified with aluminium hydrogen sulfate (ZG1). As a compatibilizer, maleic grafted polyethylene (Plb) was used. X-ray diffraction and transmission electron microscopy were used to characterize the layer structure of clays in the composites. The limiting oxygen index tests showed synergistic effect between both clays and MPP. Flammability was also examined using cone calorimetry technique. The influence of all the fillers on thermal stability (thermogravimetric analysis), crystallinity (differential scanning calorimetry and wide angle X-ray scattering techniques), and mechanical properties was also studied. © 2013 The Author(s).
Smolik M.,Silesian University of Technology |
Turkowska M.,Fertilizers Research Institute
Talanta | Year: 2013
A method of determination of low amounts of tantalum in niobium and niobium compounds without its prior separation by means of inductively coupled plasma optical emission spectrometry (ICP-OES) has been worked out. The method involves dissolution of the analyzed samples of niobium as well as its various compounds (oxides, fluorides, chlorides, niobates(V)) in fluoride environments, precipitation of sparingly soluble niobic(tantalic) acid (Nb2O 5(Ta2O5)·xH2O), converting them into soluble complex compounds by means of oxalic acid with addition of hydrogen peroxide and finally analyzing directly obtained solutions by ICP-OES. This method permits determination of Ta in niobium at the level of 10 -3% with relatively good precision (≤8% RSD) and accuracy (recovery factor: 0.9-1.1). Relative differences in the results obtained by two independent methods (ICP-OES and ICP-MS) do not exceed 14%, and other elements present in niobium compounds (Ti, W, Zr, Hf, V, Mo, Fe, Cr) at the level of 10-2% do not affect determination. © 2013 Elsevier B.V.
Arczewska M.,Lublin University of Life Sciences |
Kaminski D.M.,Lublin University of Life Sciences |
Gorecka E.,Fertilizers Research Institute |
Pociecha D.,Fertilizers Research Institute |
And 4 more authors.
Biochimica et Biophysica Acta - Biomembranes | Year: 2013
Xanthohumol (XN) is the major prenylated flavonoid found in hop resin. It has attracted considerable attention in recent years due to its wide spectrum of biological activities and the beneficial effect on human health. Since lipid membrane is first target for biologically active compounds, we decided to investigate the influence of XN on the dipalmitoylphosphatidylcholine (DPPC) multibilayers. Interactions of XN with DPPC were investigated as a function of temperature and its concentration by using X-ray diffraction and the ATR-FTIR spectroscopy techniques. The aim of understanding the mechanisms of molecular interactions between XN and DPPC was to indicate the localization of the XN with respect to the membrane and the type of interaction with phospholipids. The results revealed that XN changes the physical properties of the DPPC multibilayers in the form of dry film. A new complex formation between XN and DPPC is reported. The detailed analysis of refraction effect indicates the changes in electron density ratio between hydrophobic and hydrophilic zones of lipid at phase transition. This is in compliance with reported changes in FTIR spectra where at pretransition XN moves from interface region between polar heads to the neighborhood of phosphate groups. © 2012 Elsevier B.V. All rights reserved.
Cichy B.,Fertilizers Research Institute |
Kuzdzal E.,Fertilizers Research Institute
Industrial and Engineering Chemistry Research | Year: 2014
A continuous MSMPR (mixed-suspension mixed-product removal) crystallizer was used in the process of obtaining melamine phosphate in a precipitation reaction. The effects of the mean residence time of the suspension in the crystallizer and of the concentration of the melamine suspension in water on the efficiency of the process and the quality of the product obtained were studied. Kinetic parameters of the reaction crystallization process under study were estimated. The grain size distribution of the crystals and the specific surface area of the grains were determined. Morphology was defined by means of a shape factor and coefficients of inhomogeneity and variation. Well-formed, homogeneous crystals of similar specific surface areas and practically identical small pore volumes were obtained. This work shows that, within the studied range of solid-phase concentrations and mean residence times, it is possible to obtain a product of monodisperse grains and predicted grain size by controlling the concentration of the melamine suspension and the reaction time during the synthesis process. © 2014 American Chemical Society.
Kowalik P.,Fertilizers Research Institute |
Prochniak W.,Fertilizers Research Institute |
Borowiecki T.,Maria Curie Sklodowska University
Catalysis Today | Year: 2011
The following contribution shows the results of investigations on an influence of alkali metals compounds on physicochemical and catalytic properties as well as the most important operating parameters of Cu/ZnO/Al2O3 system, with a composition being similar to typical industrial heterogeneous catalysts for LT-WGS process. The addition of cesium or potassium to the Cu/ZnO/Al2O3 catalyst causes a decrease of copper surface. It gives remarkable inhibition of methanol synthesis, accompanying by a relatively small influence on the activity towards WGS. © 2011 Elsevier B.V.