Early Effects of Hyperbaric Oxygen on Inducible Nitric Oxide Synthase Activity/Expression in Lymphocytes of Type 1 Diabetes Patients: A Prospective Pilot Study

This study aimed at examining the early effects of hyperbaric oxygen therapy (HBOT) on inducible nitric oxide synthase (iNOS) activity/expression in lymphocytes of type 1 diabetes mellitus (T1DM) patients. A group of 19 patients (mean age: 63 ± 2.1) with T1DM and with the peripheral arterial disease were included in this study. Patients were exposed to 10 sessions of HBOT in the duration of 1 h to 100% oxygen inhalation at 2.4 ATA. Blood samples were collected for the plasma C-reactive protein (CRP), plasma free fatty acid (FFA), serum nitrite/nitrate, and serum arginase activity measurements. Expression of iNOS and phosphorylation of p65 subunit of nuclear factor- κ B (NF κ B-p65), extracellular-regulated kinases 1/2 (ERK1/2), and protein kinase B (Akt) were examined in lymphocyte lysates by Western blot. After exposure to HBOT, plasma CRP and FFA were significantly decreased ( p < 0.001 ). Protein expression of iNOS and serum nitrite/nitrate levels were decreased ( p < 0.01 ), while serum arginase activity was increased ( p < 0.05 ) versus before exposure to HBOT. Increased phosphorylation of NF κ B-p65 at Ser 536 ( p < 0.05 ) and decreased level of NF κ B-p65 protein ( p < 0.001 ) in lymphocytes of T1DM patients were observed after HBOT. Decreased phosphorylation of ERK1/2 ( p < 0.05 ) and Akt ( p < 0.05 ) was detected after HBOT. Our results indicate that exposure to HBO decreased iNOS activity/expression via decreasing phosphorylation of ERK1/2 and Akt followed by decreased activity of NF κ B

The possibility of in vitro multi-enzymatic method application for the assessment of the influence of thermal treatments on organic matter digestibility of feed for ruminants

In vitro multi-enzymatic method is a two-step procedure that uses exogenous enzymes for incubation of feed that aim to imitate digestive processes in the animal. It is used for determination of organic matter digestibility (OMD) of various feedstuffs and complete mixtures used in ruminant nutrition. The aim of the present work was to determine whether this in vitro multi-enzymatic method can be applied for the assessment of the influence of thermal treatments on OMD of feed for ruminants. Samples of corn and complete mixture for cows (based on corn) were subjected to pelleting, steam flaking, micronization and extrusion. Statistical analysis of the results did not show significant increase of corn and complete mixture OMD after various thermal treatments compared to untreated samples, which can be explained by high digestibility of corn itself (exceeds 90%). Based on obtained results it can be concluded that applied in vitro method is not suitable for the assessment of the influence of thermal treatments on OMD of corn and corn based mixture, while future research should be broadened to analysis of samples with lower OMD, such as sorghum, oats and barley

Seasonal water pricing using meteorological data: case study of Belgrade

The paper presents a model of seasonal water pricing (SWP) aimed primarily at diminishing excessive fresh water use in the city of Belgrade. Seasonal prices are determined on meteorological observations of the average monthly temperatures and the total monthly precipitations in the period from 2000 to 2010, and their deviations from the thirty year normal levels. The SWP operation is based on an ex-post price determination, and it conveys a signal to water users on resource scarcity. Not knowing ex ante how high their monthly bill is going to be, but aware of the price-setting rule, consumers will be in a situation to change their pattern of behaviour towards a more sustainable water use. Potential of the SWP model implementation are a) pushing consumers towards rationality, b) valuable resource conservation and c) enabling the water supply company to cover peak-season supply and the related costs. The SWP model has been created for the Belgrade Water and Wastewater Company, but might be easily implemented in all other cities with the same problems

Volatile organic compounds (VOC) policy innovation in petrochemicals river barge transportation

The aim of this paper was to emphasise the need for a volatile organic compounds VOC policy review in the field of river barge transportation of petrochemicals. Review of the VOC policy shows that barges neither fall under an integrated pollution prevention and control permit nor any other regulation or incentive related environmental policy. Current situation and trend in this area is presented through a case study of the Danube River, Serbia. The case study shows that evaporative losses have increased c ca 22 times in period 2006-2010 and, that vapour collection system can reduce VOC emissions by up to 3 times. A proposal for improved VOC policy has been developed in detail based on the following elements: a) The appropriate Best Available Techniques reference document (BREF) should include the transport sector; b) Mandatory reporting of VOC emitted during barge transport of crude oil and crude oil derivates should be introduced, and c) A pollution charge should be introduced on all barges without vapour collection system installed "onboard". Three potential scenarios for the VOC charge are presented, which vary according to the charge introducing dynamics. The differences between scenarios are in initial levels of charge, but the final charge is same for all three and it is proposed to be 220 (sic) per capacity ton

Modified screw conveyor-mixers - Discrete element modeling approach

Screw conveyors are widely used in the food industry, building construction and mining companies, chemical, agricultural and processing industries, mostly for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity, the improvement of the transport parameters is a very demanding task and designers usually have to rely on data obtained from empirical investigations. In this paper, fifteen horizontal single-pitch screw conveyors with modified geometry and the different lengths were investigated for premixing action, during the transport of materials. All investigations were performed experimentally and numerically, by using Discrete Element Method (DEM). The influences of screw length, observed geometry variations and different types of screw design, on the performances of the screw conveyor-mixer during material transport were explored. The auxiliary mixing action (used to improve the mixing process) was achieved during the transport of the material. The geometry of the screw conveyor is changed by adding three complementary helices oriented in the same or the opposite direction from screw blades. The particles of the material being transported tumble down from the top of the helix to the next free surface, and that segment of helix was used for additional mixing action. According to experiments and DEM analysis, the particle path length is increased, with the observed modification of screw conveyor, and the improved geometry could be determined for increasing the quality of mixing. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved

DEM/CFD approach for modeling granular flow in the revolving static mixer

DEM/CFD (Discrete Element Method/Computational Fluid Dynamic) approach was used to develop a three dimensional model of fluid flow and mixing process of solid particles within the revolving static mixer, type Komax. Static mixers are widely used in process industry, food industry, pharmaceutical and chemical industry. Mixing process adds significant value to the final product and it can be regarded as a key process. The quality and the price of the product often depend on mixing efficiency. Both design and operation of the mixing unit itself have a strong influence on the quality produced. In this paper, DEM is used for modeling granular flow of zeolite spheres in the revolving Komax static mixer and CFD method was used for modeling fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable analysis of particle motion and flow pattern of the working fluid. The objective of this paper is to predict the behavior of particles after several rotations of the revolving static mixer. This type of device is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. The results of the numerical simulation are compared with appropriate experimental results. The special design revolving static mixer, made of transparent Plexiglas was used for this experiment. Mixing quality was examined by RSD (relative standard deviation) criterion. Application of this model provides the optimization of the number of revolutions and geometrical parameters of mixing process taking into account the quality of the mixing process. (c) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved

Mathematical model, numerical simulation and optimization of rotating valve feeder in animal feed production

The processes of transportation of bulk materials from silos and hoppers are significant in various industrial applications because of their influences on material characteristics and working parameters of the production process. In this paper, a rotating valve feeder, with eight vanes was investigated for transport action of bulk materials, such as wheat, maize and rice, which were ground, using the sieve sizes of 1, 3 and 5 mm. The rotating valve feeders under investigation have proven to be useful in transportation processes despite their construction simplicity. All investigations were done experimentally and numerically, using coupled Discrete Element Method (DEM) and Computational Fluid Dynamics calculation (CFD). The influences of different types of bulk materials and its particle size, on the performances of the rotating valve feeder during material transport were explored. The artificial neural network was developed (in the form of a multi-layer perceptron model) in order to optimize the granular flow of the bulk material, showing the high prediction capability of bulk density, dosing time and granular material flow, with the coefficient of determination equal to 0.999 during the training period. The decreasing of the sieve opening diameter caused the decrease in bulk density of the ground material, but statistically significant only for rice, as seen from the experiments and the results of the neural network model. The 5 mm sieve ensured the material with the highest flowability, significantly increasing the granular flow and decreasing the dosing time. The granular particles were modelled as the spheres in the DEM/CFD simulation, with a small-sized triangular surfaces. The DEM/CFD prediction of the mass transport for rice, wheat and maize was quite adequate, obtaining the coefficient of determination being 0.997; 0.998 and 0.849, respectively

The joint mixing action of the static pre-mixer and the rotating drum mixer – Discrete element method approach

In this study, the mixing performance of coupled mixing action of the Komax static mixer (which is used as a pre-mixer) and rotating drum (applied as the final mixer) was explored in the maize meal mixing operation. The main objective of this paper was to predict the behaviour of the previously grinded maize particles, during the mixing process in static mixer and drum mixer, and to explore the possibilities to shorten the mixing time in the main mixer (in order to reduce the energy consumption). Three different experiments were performed: in the first experiment, possibilities of static mixer were explored, second experiment showed the mixing performance of rotating drum, and the combination of these two mixing devices was investigated in the third experiment. Homogeneity of the obtained mixtures was determined experimentally, by the “Microtracers” method. The Discrete Element Method was used for modelling of granular flow in the pre-mixing and final mixing applications, and to predict the inter-particle mixing quality within a static mixer and the rotating drum mixer. The results of the numerical simulation are compared with appropriate experimental results. The possible industrial application of this model could be the optimization of parameters of mixing systems taking into account the quality and the duration of the mixing process