The Effect of Methacrylic Acid and Maleic Acid on the Isothermal Kinetics of Acrylic Acid Crosslinking Co-polymerization under Conventional and Microwave Heating

The kinetics of free-radical crosslinking co-polymerization (FRCCP) of acrylic acid (AA) with both methacrylic acid (MA) (PAMA hydrogel ) and maleic acid (MAL) (PAMAL hydrogel) was investigated under the conditions of isothermal conventional heating (CH) and under the conditions of microwave heating (MWH) with controlled cooling.   The kinetics curves of FRCCP of PAMA and PAMAL hydrogels under the conditions of CH are described with the kinetics model of second order chemical reaction, whereas the kinetics curves under the conditions of CH are described with the kinetics model of Polany-Winger.  It is proved that MWH leads to the changes in the rate of  FRCCP and to the changes in the values of the kinetic parameters (activation energy (Ea) and pre-exponential factor (lnA).  It was found the existence of relationship between the values of the kinetic parameters calculated for MWH and CH for PAMA and PAMAL hydrogel synthesis process, which is well-known as compensation effect. The effect of MWH on the kinetics of FRCCP for PAMA and PAMAL hydrogel formation were explained by applying the model of activation by selective energy transfer (SET). The changes in kinetics model, rate of FRCCP and kinetics parameters, caused with the MWH can found wide application in designing novel technologies for obtaining polymers and for synthesis of polymers with  novel physico-chemical properties.  The suggested mechanism of activation for polymerisation under the conditions of MWH also enables development of novel reaction systems and technologies for polymers productions.

Korišćenje savremenih tehnoloških postupaka u proizvodnji hrane za ribe različitih fizičkih karakteristika

In order to produce fish feed which can satisfy the nutritive requirements and the ever stricter legislation on environment protection, it is necessary to maintain appropriate physical properties of the finished product. When referring to the physical properties of fish feed, we usually think about shape, particle size, their specific weight or bulk density and water stability. Technological production methods are the decisive factor for obtaining these properties, in addition to the well balanced nutritive demands and the adequate quality of raw materials. The goal of this paper is to point out the most important parameters of technological procedures for fish feed processing which are immediately related to the physical properties of the feed. This is presented through examples of specific products which are used by the “FSH Komponenta” company from Ćuprija in Serbia in order to offer potential solutions for certain demands in the fish feed industry

Cerebral Amyloid Angiopathy-Related Inflammation (CAA-rI): Three Heterogeneous Case Reports and a Focused Literature Review

Cerebral amyloid angiopathy-related inflammation (CAA-rI) is a largely reversible, subacute encephalopathy, which is considered as a rare variant of cerebral amyloid angiopathy (CAA). Although the diagnosis of this inflammatory vasculopathy is generally clinico-pathologic, a probable or possible diagnosis can often be established based on current clinico-radiological diagnostic criteria. This is important since CAA-rI is considered as a treatable disorder, which most commonly occurs in the elderly population. Behavioral changes and cognitive deterioration are highlighted as the most common clinical signs of CAA-rI, followed by a heterogeneous spectrum of typical and atypical clinical presentations. However, despite the well-established clinical and radiological features incorporated in the current diagnostic criteria for this CAA variant, this rare disorder is still insufficiently recognized and treated. Here, we have shown three patients diagnosed with probable CAA-rI, with significant heterogeneity in the clinical and neuroradiological presentations, followed by different disease courses and outcomes after the introduction of immunosuppressive treatment. Moreover, we have also summarized up-to-date literature data about this rare, yet underdiagnosed, immune-mediated vasculopathy

MCNP simulation of the dose distribution in liver cancer treatment for BNC therapy

The Boron Neutron Capture Therapy (BNCT) is based on selective uptake of boron in tumour tissue compared to the surrounding normal tissue. Infusion of compounds with boron is followed by irradiation with neutrons. Neutron capture on 10B, which gives rise to an alpha particle and recoiled 7Li ion, enables the therapeutic dose to be delivered to tumour tissue while healthy tissue can be spared. Here, therapeutic abilities of BNCT were studied for possible treatment of liver cancer using thermal and epithermal neutron beam. For neutron transport MCNP software was used and doses in organs of interest in ORNL phantom were evaluated. Phantom organs were filled with voxels in order to obtain depth-dose distributions in them. The result suggests that BNCT using an epithermal neutron beam could be applied for liver cancer treatment. © 2014 Versita Warsaw and Springer-Verlag Wien

Degradation of Topciderska River Water Quality (Belgrade)

In this paper a study of degradation of water quality of Topciderska River has been shown. Topciderska River flows through Belgrade city nucleus and presents one of the most polluted rivers in this area, which joins to Sava river upwards from confluence of Sava and Danube. Various techniques have been used such as Ion chromatography (IC), Inductively coupled plasma emission spectroscopy (ICP-OES) and measurements, conductonetis and phisical parametars. Anions were analysed with ion chromatography and cations were determined with ICP-OES. The chosen locations in which sampling was done are situated in lower part of Topciderska river. Sediment, as the larges strorage and resorces of heavy metal (HM), plays a rather important role in metal transformations. The pH and HM can directly change metals distribution in sediment; however temperature and conductivity, mainly through changing the pH values, indirectly alters metals distribution. This river is one of the most polluted urban flows in Serbia. It represents good example for studying hydrologic changes influenced by social processes

Degradation of Topciderska River Water Quality (Belgrade)

In this paper a study of degradation of water quality of Topciderska River has been shown. Topciderska River flows through Belgrade city nucleus and presents one of the most polluted rivers in this area, which joins to Sava river upwards from confluence of Sava and Danube. Various techniques have been used such as Ion chromatography (IC), Inductively coupled plasma emission spectroscopy (ICP-OES) and measurements, conductonetis and phisical parametars. Anions were analysed with ion chromatography and cations were determined with ICP-OES. The chosen locations in which sampling was done are situated in lower part of Topciderska river. Sediment, as the larges strorage and resorces of heavy metal (HM), plays a rather important role in metal transformations. The pH and HM can directly change metals distribution in sediment; however temperature and conductivity, mainly through changing the pH values, indirectly alters metals distribution. This river is one of the most polluted urban flows in Serbia. It represents good example for studying hydrologic changes influenced by social processes