Thermal behaviour of a moving steel strip cooled by an array of planar water jets

A mathematical model has been developed to predict the temperature distribution in a moving strip of steel cooled by an array of planar water jets. Experimentally determined nucleate boiling and analytically obtained single-phase convection and film boiling heat transfer coefficients are used as convective boundary conditions, and thermophysical property variations of the steel with temperature are considered in the analysis. The model equation for the strip temperature distribution is solved numerically, and the model is validated by comparing predicted coiling temperatures with measurements obtained on the runout table of a steel mill.     

Complexity-based quality indicators for human and social capital in science and research: the case of Serbian Homeland versus Diaspora

Scientometrics - We developed quality indicators model for measuring human and social capital in the scientific and research communities, grounded in the complexity science. The model was...     

Development of whey-based beverages

This paper considers beverages consisting of whey, fruit components (orange, pear, peach, and apple), citric acid and sucrose. It also offers their optimal composition. The dry matter of the fruit component, the pH of the beverage and its sucrose content were independent variables. Blends were prepared in accordance with the factorial design. After pasteurization, they were exposed to a sensor analysis so that the following characteristics were estimated: flavour, odour, colour, sediment, appearance and total quality (sum of the previous factors). By applying the regression analysis method, a mathematical model of each characteristic was derived. None of the characteristic functions had an extreme, so the maxima lay at the boundaries of the independent variables (6% of dry matter and 4% or 2% of sucrose ). Only the pH changed within a narrow range. The statistical method has shown that the quality of blends with orange and pear mostly depends on the sucrose content, while the quality of blends with peach and apple depends on the dry matter of the fruit. Interaction of dry matter and sucrose is most significant for the blend with pear, while the balance between sucrose and pH strongly depends on the quality of all the other products. The peach–whey beverage containing 6% of dry matter and 2% of sucrose as well as having pH 3.6 proved to be the best.     

Predictive value of serum myeloperoxidase activity for thrombosis of arteriovenous fistulas

Myeloperoxidase is a proinflammatory protein that appears as a result of increased oxidative stress. It plays an important role in the promotion and progression of atherosclerosis. The aim of this study was to determine the importance of MPO as a predictive parameter for thrombosis of arteriovenous fistula (AVF). The study involved monitoring patients with AVFs for hemodialysis over a period of 2 years. There were 41 patients, 19 (46%) men and 22 (54%) women, with mean age of 65 ± 12.7 years. Routine laboratory analyses were carried out in all respondents, including determination of MPO concentration. Gender, demographic and anthropometrical characteristics, smoking, alcohol consumption, as well as the presence of diabetic nephropathy, as an etiological factor of kidney disease, were recorded. The group of patients who developed initial thrombosis of the AVFs had significantly different values for leukocytes (8.5 ± 3.8 vs. 7.3 ± 2.1, P = 0.024), erythrocytes (2.8 ± 0.27 vs. 3.2 ± 0.65; P = 0.019), hemoglobin (88.5 ± 81 vs. 99.1 ± 6.02; P = 0.041), and myeloperoxidase (19.3 ± 4.67 vs. 11.1 ± 4.43; P = 0.007) when compared with the group without fistula thrombosis. Diabetic nephropathy (P = 0.02) characterized the group of patients with thrombosis of the fistula. Diabetic nephropathy (B = 2.53, P = 0.049) and MPO (B = 0.03, P = 0.029) were statistically significant predictors of fistula thrombosis. In our study, MPO and diabetic nephropathy were predictors of thrombosis of the AVF.     

Development of an Environmentally Acceptable Detergent Formulation for Fatty Soils Based on the Lipase from the Indigenous Extremophile Pseudomonas aeruginosa Strain

A lipase derived from an indigenous extremophile Pseudomonas aeruginosa strain isolated from rancid metalworking fluid was evaluated as a detergent additive. Applicability of the obtained enzyme as an additive in detergent formulations was confirmed by its implementation in the formulations of several new products differing in surfactant type and concentrations, demonstrating satisfactory performance in terms of degreasing efficiency and composition of the washing wastewater. The degreasing efficiency of different enzyme‐containing detergent formulations was studied on cotton fabric samples stained with triolein and compared to that of formulations containing only surfactant. The highest efficiency of the fatty soil removal in formulations with a low content of surfactants (0.4 %) was noted in the enzyme formulation containing Lutensol^® XP‐80 (degreasing efficiency >80 %) and Triton^® X‐100 (degreasing efficiency >60 %). An attempt was then made to optimize the composition of the enzyme formulation on the basis of one or both of these surfactants using statistically planned experiments and response surface methodology (RSM). Taking into consideration the environmental aspects and the shown detergency, it appeared that rather high degreasing effects were achieved in formulations based on a low quantities of Lutensol^® XP‐80 (0.4 %) at all pH values. However, pH seemed to have a notable effect since the degreasing efficiency significantly increased with increasing pH and the amount of the enzyme. Formulations having a moderate alkaline pH profile and higher amount of enzyme exhibited a high cleaning performance of fatty soil even at a low concentration of the surfactant.     

Influence of starter cultures on the free fatty acids during ripening in Tea sausages

The influence of starter cultures on the free fatty acids content during ripening of Tea sausages, typical dry sausages produced in the south of Croatia, was studied. Three batches of Tea sausages were produced using different starter mixtures (Staphylococcus xylosus S81 and Lactobacillus sakei G20; Staphylococcus xylosus S142 and Lactobacillus sakei G20; Staphylococcus xylosus S206 and Lactobacillus sakei G20), while the control batch was produced without a starter. The amounts of free fatty acids present in the samples at the end of the ripening period were not significantly different, suggesting that the lipolytic enzymes naturally occurring in meat could play a predominant role in the free fatty acids release. Oleic and linoleic acids were present in the highest concentrations, while only small quantities of short-chain fatty acids were detected, with acetic acid being the most representative one.     

Retinal Ciliopathy in the Patient with Transplanted Kidney: Case Report

A review of a rare case of a proven mutation in the RP1 gene (RP1c.2029C>T, p. (ARG677*) in a kidney transplant patient was presented herein. According to his medical history, he had tonsillectomy performed at the age of 20 due to erythrocyturia, and at the age of 32 he was treated for malignant hypertension. The patient had been diagnosed with chronic renal failure at age 56 years. During an eye examination in 2016, retinitis pigmentosa was suspected and the patient was advised to run further tests. After an ophthalmological examination and tests, genetic testing was performed and a mutation in the RP1 gene encoding a family of proteins which are components of microtubules in photoreceptor primary cilia was proven. The literature search found that mutations in the RP1 gene have so far been exclusively associated with a non-syndromic form of retinal degeneration. However, the RP1 protein is expressed in the kidneys, and it remains unclear why the mutation of this gene so far was only specifically related to retinal photoreceptor function and not to arterial hypertension and renal disease. Primary cilia are thought to act as potential mechanosensory fluid-flow receptors in the vascular endothelium and kidney and their dysfunction results in atherosclerotic changes, hypertension, and chronic renal failure.     

E-Learning personalization based on hybrid recommendation strategy and learning style identification

Personalized learning occurs when e-learning systems make deliberate efforts to design educational experiences that fit the needs, goals, talents, and interests of their learners. Researchers had recently begun to investigate various techniques to help teachers improve e-learning systems. In this paper, we describe a recommendation module of a programming tutoring system - Protus, which can automatically adapt to the interests and knowledge levels of learners. This system recognizes different patterns of learning style and learners’ habits through testing the learning styles of learners and mining their server logs. Firstly, it processes the clusters based on different learning styles. Next, it analyzes the habits and the interests of the learners through mining the frequent sequences by the AprioriAll algorithm. Finally, this system completes personalized recommendation of the learning content according to the ratings of these frequent sequences, provided by the Protus system. Some experiments were carried out with two real groups of learners: the experimental and the control group. Learners of the control group learned in a normal way and did not receive any recommendation or guidance through the course, while the students of the experimental group were required to use the Protus system. The results show suitability of using this recommendation model, in order to suggest online learning activities to learners based on their learning style, knowledge and preferences.     

The missing component in rail charging modeling—access charges principle selection

The motive of this research is the fact that until now no universal model of access charges (AC) has been defined. In the process of modeling, the AC principle is one of the key elements for defining the AC. In this paper, a model for the AC principle selection based on the analytic network process (ANP) approach is proposed. The developed model presents the objectives of the identified stakeholders through the established criteria from three different perspectives: the government influence, railway market environment, and efficiency of network use. Based on the results of a research, network structure of the ANP method can successfully resolve the dependence and conflicts among evaluation criteria for the AC principle selection. The proposed ANP‐based model can become a tool for evaluation and ranking of the AC principle as shown in the case study of the Serbian Railways. This paper is based on real data.