bluuebunny/crossref_metadata_2025 huggingface dataset:
Innovation as a factor of entrepreneurship development with a special focus on Israel and disruptive innovations
Authors: Ljubičić Ivana
Published: December 2020

The subject of this paper are innovations, which play a crucial role in the development of entrepreneurship in the modern world. Sometimes it is enough for a company to make some important or even incremental innovation and to gain a market and competitive advantage. But sometimes, as in the case of the Finnish mobile phone manufacturer - Nokia, it is enough not to respond quickly enough before the emergence of a disruptive innovation and to lose 92% of the market as a result. Companies that have an environmental change rate faster than the rate of change of the company itself, i.e., those that implement innovations more slowly than the environment changes, are first doomed to lag behind others, and then also to become marginalized and eventually to disappear and be completely shut down. The importance of this paper is the innovation factor which remains paramount to the advancement of entrepreneurship, and whether it will be executed and driven in one way or another, by a government incentive or by the booming private sector, is irrelevant after all. China does this by direct government investment in innovation and innovative technologies, while in the US and to a lesser extent in Israel, it is happening in the free market. The countries of Scandinavia, Switzerland, Japan, South Korea and Singapore, as well as the "start-up nation", Israel, have a direct proportion of their GDP per capita and innovation index. This all tells us how important it is to support innovation. The induction, deduction, analysis, synthesis and, above all, desk research methods have been used for producing this paper.
An estimate of the pitting strength of steel materials
Authors: Osakue Edward , Anetor Lucky , Harris Kendall
Published: December 2020

A single expression for estimating the nominal pitting strength of steel materials, based on surface hardness, is developed from first principles for a reliability of 99% at 107 load cycles. It requires the hardness values to be measured in Vicker's hardness scale. The expression may be used for any steel material processed by hot rolling, cold drawing, quenching and tempering or case-hardening. The formulation incorporates a nominal design factor at 99% reliability which is estimated from a probabilistic model based on the lognormal probability density function. Pitting strength estimates from the expression are compared with those of American Gear Manufacturers Association (AGMA) estimates and data from other sources as indicated in Tables 3 and 4. The expression predicts lower values at low hardness but higher values at high hardness. The variance is between - 15.21% and 10.13% for through-hardened steels. For case-hardened steels, the variances range from 14.23% to 20.26% between the estimates and available data. These variances appear to be reasonable considering the many factors involved in pitting resistance. The main advantage of this study is that pitting strength of new steel materials may be estimated for initial design sizing without long and costly contact fatigue testing which of course is necessary for design validation. Also, the estimation method developed may be applied to other materials, metallic and non-metallic. Suggestions are made for estimating some pertinent pitting strength adjustment factors when considering field or service pitting strength.
Quadcopter altitude estimation using low-cost barometric, infrared, ultrasonic and LIDAR sensors
Authors: Ranđelović Dušan , Vorotović Goran , Bengin Aleksandar , Petrović Pavle
Published: December 2020

The goal of this research is to assess the different low-cost sensors for flight altitude measuring of a multirotor UAV at low altitude flight. For optimizing the sensor performances and accuracy, data filtering and other methods were applied. The flight altitude data were collected and stored for later analysis with reference to the true altitude. The correlation coefficient and the mean squared error were calculated in order to assess the sensors' performance. On the basis of the results of the study, it was possible to determine the choice of the adequate sensor for this specific use. The study showed that the best characteristics for this experiment conditions had the Garmin LIDAR-Lite V3HP sensor and the Bosch Sensortech BME280 that combined air humidity, atmospheric pressure, and air temperature sensor.
Tribological properties of nano-sized ZrO2 ceramic particles in automotive lubricants
Authors: Tóth Álmos , Szabó Á.I. , Kuti R.
Published: December 2020

The demand for decreasing CO2-emission and harmful material content of the exhaust gas of passenger cars requires the improvement of the entire powertrain including the applied lubricants. One of the possible future engines lubricant can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of nonmetallic surface materials. This paper presents the experimental investigation of ZrO2 nanoceramic powder as a lubricant additive. The tribological performance of the lubricant samples was experimentally investigated on a ball-on-disc translation tribometer. An optimum concentration was found at 0.4 wt%, where the wear scar diameter on the ball specimen was reduced by more than 40% compared to the reference sample. The SEM-analysis confirmed the mending mechanism theory: nanoparticles were revealed to aggregate between the asperities resulting in a significantly smoother contact surface.
Process modeling of sequential radial-direct extrusion using curved triangular kinematic module
Authors: Hrudkina Natalia
Published: December 2020

In this article new engineering calculations such as the value of the relative strain pressure for the combination of a triangular kinematic module with external modules of various configurations are developed. This allowed us to describe qualitatively the nature of the metal flow in the reversal zone before radial extrusion. This made it possible to achieve a decrease in the predicted assessment of the power mode for the deformation process with comparison by the use of rectangular modules. The greatest reduction in the value of the relative strain pressure corresponded to a combination with an adjacent rectangular module (with the missing vertical component CPVF) and can obtain 7-8%. The deviation of the theoretical results in the power parameters of the process by using a triangular kinematic module are 12-15% for a process with a developed flow radial component. The resulting calculations can be used to model new cold extrusion processes.
Performance analysis of a solar chimney power plant for different geographical locations of Saudi Arabia
Authors: Hussain Faisal , Rehman Shafiqur , Al-Sulaiman Fahad
Published: December 2020

In this study, a detailed performance analysis was conducted by analysing the energy model of solar chimney power plant. The developed model was used for five locations (cities) in Saudi Arabia for a comparative study. The selected cities were Jubail (East), Arar (North), Umluj (West), Sharurah (South) and Shaqra (Central). The solar irradiation, sunshine hours, ambient temperature and atmospheric pressure was used to determine the output power, efficiency, and other performance parameters for the chosen size of plant. The data analysis showed that the highest annual average solar irradiation was at Sharurah (551W/m2) and the lowest for Jubail (456W/m2). The highest and lowest average ambient temperatures were found at Sharurah (303K) and Umluj (301K). Study reveals that annual average efficiency for Jubail is highest followed by Umluj. Furthermore, the output power, energy efficiency, variation of floor and air temperatures and pressure across turbine and chimney, variation of the mass flow rate and, the turbine inlet velocity are reported for all the months during the year for the selected five cities of Saudi Arabia.
Effect of post-fabrication treatments on surface residual stresses of additive manufactured stainless steel 316L
Authors: Barath Kumar , Aravindan K.M. , Vinoth Jebaraj , Sampath Kumar
Published: December 2020

In this work, an investigation was made to analyze the surface residual stresses on additive manufactured stainless steel AISI 316L in as-built and post-treated conditions. Direct metal laser sintering was used to fabricate the metal blocks. X-ray residual stress analysis on the as-fabricated surface revealed the presence of an inhomogeneous and irregular distribution of residual stresses in the as-built condition ranging from - 30 MPa to 111 MPa. It was mainly due to the localized laser heat source that caused variations in stresses at a lattice level. Heat treatment was performed for providing relief to the residual stress from the as-built condition showed significant relief of residual stress, which was lesser than 50% compared to as-built condition. Beneficial compressive residual stress induced by shot peening and lapping resulted in high magnitude compressive stresses on the surface. Also, homogeneous distribution of residual stress was found on the peened and lapped surface layer with an average of - 531 MPa and - 554 MPa, respectively.
LT - contradiction matrix
Authors: Rajić Dušan
Published: December 2020

Altschuller's Contradiction Matrix and Bartini-Kuznetsov's LT - Table represent two different tools for solving inventive problems based on the same dialectical principle. It starts from the premise that there are contradictions at the root of every problem. Although both tools are designed to make it easier to come up with the Ideal Final Solution (IFS), in practice they often come up with optimal rather than ideal solutions. One of the reasons for this phenomenon can be attributed to the subjectivity of the innovator arising from the logical-descriptive Theory of Inventive Problem Solving (TIPS / rus. TRIZ). The second reason is related to the existence of unidentified laws of nature shown in the LT table of physical quantities. The integration of these two tools yields an effective LT contradiction matrix as a new inventology tool, which does not have the disadvantages of the individual tools from which it arose.
New design of miniature C-band substrate integrated waveguide bandpass filters using ceramic material
Authors: Rhbanou Ahmed , El Fadl , Jebbor Nawfal , Bri Seddik
Published: December 2020

This article presents new structures and methods of design of miniature third-order substrate integrated waveguide (SIW) bandpass filters on a high-permittivity ceramic substrate for the C-band. The aim was to appraise the feasibility of such filters by using a 3D electromagnetic (EM) simulator. The substrate integrated waveguide (SIW) offers good quality factors and electrical performances compared with other planar techniques. Its integration capabilities and fabrication cost are other benefits that make it attractive. Ceramic material offer electrical properties suitable in designing of passive devices. High relative permittivity with low dielectric losses makes it possible to miniaturize passive components while exhibiting high temperature stability, which is an important selection criterion for a filter designed to equip the payload of a satellite. Three SIW filters were designed on a Trans-Tech ceramic substrate (thickness = 254 mm, er = 90, and tand = 0.0009) with drastic specifications for space application. The first filter is composed of three SIW resonators with direct coupling, the second is composed of three SIW resonators with a cross-coupling to create a transmission zero, and the third is composed of three SIW resonators with circular holes etched on the top of the metal layer to achieve a super-wide band. The obtained results for the proposed filters are presented, discussed, and compared with relevant published literature. The proposed filter can be used to enhance the performance of microwave devices used for C-band, especially Satellite communications.
Numerical simulation of flow in trapezoidal labyrinth-channels of drip irrigation
Authors: Ouarriche Hamza , El Bouhali , Bouisfi Firdaouss , Chaoui Mohamed , Hannaoui Mohamed
Published: December 2020

The clogging of emitters has been considered as one of the most troublesome problems inhibiting the extension of drip irrigation. This paper investigates the flow field of water and behaviour of suspended particles in the trapezoidal labyrinth-channel. Computational Fluid Dynamics methods has been executed on liquid-solid two-phase flow in labyrinth-channel emitters. RNG k-e turbulence model was used to evaluate four types of emitters that have the same characteristics and differ in the elbow width S. This study has shown that as the value of S increases, the maximum velocity in the labyrinth-channel decreases and the number of vortices increases. However, emitter with a high S value are more subtle to clogging. In addition, it was also observed that smaller diameter particles behave best when they pass through the channel and follow the streamline flow. As the particle diameters become larger, the particles tend to leave the mean stream and enter the vortex zones under the force of inertia. So, more suspended particles trapped in the vortex area , more the chances of emitter clogging increase. All of these furthermore confirm that vortex and low speed regions were the main causes leading to emitter clogging.
The role of reverse logistics in the transition to a circular economy: Case study of automotive spare parts logistics
Authors: Makarova I. , Shubenkova K. , Buyvol P. , Shepelev Vladimir , Gritsenko A.
Published: December 2020

The article describes the ways of industrial development in the era of transition from a linear model of the economy to a circular model, as well as new trends in the development of logistics. It shows the interconnection of processes in production systems, logistics and services, their role in ensuring sustainable green growth. It is shown that by closing the loop of product lifecycles, reverse logistics plays an important role to transitioning to a circular economy. The article presents an example of planning the supply of spare parts when organizing services in foreign markets. Planning is based on multidimensional analysis of failure and modeling data. For this purpose, an information system was developed. The found failure probabilities of units and parts were used to build a model of the reverse logistic chain, within which the parameters of the formation of a reverse flow, differentiated for various operating conditions and vehicle subsystems, were introduced for the first time.
Analysis of the motion and stability of the holonomic mechanical system in the arbitrary force field
Authors: Vesović Mitra , Petrović Goran , Radulović Radoslav
Published: December 2020

In order to give an insight into the work of the machine before the production and assembly and to obtain good analysis, this paper presents detailed solutions to the specific problem occured in the field of analytical mechanics. In addition to numerical procedures in the paper, a review of the theoretical foundations was made.Various types of analysis are very common in mechanical engineering, due to the possibility of an approximation of complex machines. For the proposed system, Lagrange's equations of the first kind, covariant and contravariant equations, Hamiltons equations and the generalized coordinates, as well as insight in Coulumb friction force are provided.Also, the conditions of static equilibrium are solved numerically and using intersection of the two curves. Finally, stability of motion for the disturbed and undisturbed system was investigated.
Multiphysics simulation of piezoresistive pressure microsensor using finite element method
Authors: Pashmforoush Farzad
Published: December 2020

In this study, the electro-mechanical behavior of a specially designed highsensitive piezoresistor pressure microsensor was simulated using finite element method, through COMSOL multiphysics software. The mechanical deformation of the diaphragm and the distribution of electrical potential in the piezoresistive were evaluated for various pressure values. In order to determine the influence of the temperature sensitivity parameter, different temperature conditions were investigated. According to the obtained results, by increase of the applied pressure, the resistance of the piezoresistor decreased, while, the sensitivity increased. Also, it was observed that at constant pressure, as the temperature increases, the stress on the diaphragm surface decreases, indicating high stress distribution at the sides and the middle of the diaphragm at low temperatures such as -50 °C. Furthermore, the obtained results demonstrated that temperature variations were not very effective on the potential distribution in the piezoresistor. However, the temperature coefficient of sensitivity demonstrated an increasing tendency with increase of the temperature from -50 °C to 50 °C.
Human activity recognition based on machine learning classification of smartwatch accelerometer dataset
Authors: Radivojević Dušan , Mirkov Nikola , Maletić Slobodan
Published: December 2020

This paper presents two Machine Learning models that classify time series data given from smartwatch accelerometer of observed subjects. For the purpose of classification we use Deep Neural Network and Random Forest classifier algorithms. The comparison of both models shows that they have similar performance with regard to recognition of subject's activities that are used in the test group of the dataset. Training accuracy reaches approximately 95% and 100% for Deep Learning and Random Forest model respectively. Since the validation and recognition, reached about 81% and 75% respectively, a tendency for improving accuracy as a function of number of participants is considered. The influence of data sample precision to the accuracy of the models is examined since the input data could be given from various wearable devices.
Influence of geology on tunnel boring machine performance: A review
Authors: Pandey P.K. , Raina A.K. , Deshmukh S. , Trivedi R. , Vajre R. , Murthy V.M.S.R.
Published: December 2020

Tunnel boring machines are used for excavating a variety of soils and rocks for circular cross-section tunnels. Several published studies examined the role of rockmass in determining the cutting and advance rate of tunnel boring machines. A comprehensive review of literature was conducted to ascertain the influence of geological conditions on the performance of tunnel boring machines and revealed that different rock characteristics were used to define the tunnel boring machine performance. The progress of the tunnel boring machine was ascribed to the inherent properties of the rockmass, intact rock properties, and surrounding geological conditions. Several authors found that extreme geological conditions strongly influence the advance of the machine. The review revealed that joint spacing, angle between plane of weakness and tunnel axis, rock quality designation, and number of joint sets were the most important variables that influenced the advance rates of the tunnel boring machine. At least 12 intact rock variables were used to define tunnel boring machine performance with one to seven such variables used in combination. The compressive strength, tensile strength, and brittleness index emerged as most crucial intact properties. Rockmass classifications or indices of tunnel boring machine performance were used by different authors to predict their performance and even to define their selection methodology. Use of dynamic properties of rock/rockmass was identified as a grey area for future research by scientists.
Recovery of ZnO from lead-zinc flotation tailings by hydrometallurgical processes: XRD, SEM, and AFM studies
Authors: Perek K.T. , Benli B. , Arslan C. , Arslan F.
Published: December 2020

The hydrometallurgical route of zinc hydroxide and synthesis of nanocrystalline ZnO is a particularly attractive method to recover oxidized lead and zinc from lead-zinc flotation tailings. In Turkey, lead-zinc complex/mixed ores along with high iron content are not suitable for conventional mineral processing methods and need hydrometallurgical treatments. Therefore, the control of iron during zinc processes is really important. In this study, hydrometallurgical process route for zinc recovery from Pb-Zn flotation tailings was investigated by considering the effects of H2SO4 concentration, leaching and roasting temperatures on the zinc dissolution considering the Eh-pH variations. The iron and zinc products were also individually examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images in order to compare before and after leaching, precipitation and roasting steps. 83.1% Zn and 91.6% Cd leaching efficiencies were obtained from Pb-Zn flotation tailing particles with the size range of 50-110 nm from AFM image cross-sections, while lead and iron were not dissolved. Elemental sulfur started to form and produce a layer around the particles or a partially agglomerated particle in the size of 170 nm during the sulphuric acid leaching. However, majority of the particles was determined to be less than 20 microns, and AFM images showed that the size reduction between the leached and unleached particles was over 50%. Selective precipitations of iron and zinc in the form of hydroxide were performed in high recovery efficiencies of 90.1% and 99%, respectively. After the heat treatment, nanocrystalline zincite clusters of 96.6% purity were produced in the ZnO mineral form and nearly 13 nm in size. Zinc can be successfully recovered and a flotation tailings ore can be a good candidate for the production of high technology needs of nanocrystalline ZnO nanoparticles.
Determination of surface moisture and particle size distribution of coal using online image processing
Authors: Choudhary P. , Maloo T. , Parida H. , Khatri P. , Deo B. , Chattopadhyay P.
Published: December 2020

Production of sponge iron requires iron ore, coal, and dolomite. The quality of sponge iron is affected by particle size variation and moisture content of the feed materials. In the present work, image processing was used to detect both particle size and moisture variation of the feed materials on an online basis. Noise and signal irregularities in images were removed by image analysis through MATLAB. Continuous (online, every 30 minutes) images were taken over a coal bed which was moving on a conveyor belt. It was a challenge to determine the particle size distribution and surface moisture of coal online. The distribution of reflectivity of coal in the image varied according to the moisture content and particle size. It affected the intensity information of the image which was then used to predict the surface moisture content of the coal. The method is now being used successfully in a processing plant.
Model for ore deposits selection by using the fuzzy TOPSIS method
Authors: Popović G. , Stanujkić D. , Karabašević D. , Štirbanović Z.
Published: December 2020

Decision-makers are often being faced with imprecise and ambiguous data. In such circumstances, the use of extended Multiple-Criteria Decision-Making (MCDM) method is more appropriate than the use of other classic decision-making techniques. This paper develops an evaluation model based on the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) to help the selection of the appropriate ore deposit for exploitation in a fuzzy environment. The applicability of the proposed model is demonstrated with a real case study involving four alternative ore deposits, seven evaluation criteria, and 3 decision-makers.
Epidemic of influenzae A H1N1 in 2019 in the Zlatibor district
Authors: Pavić Slađana , Raković-Radivojević Jelena , Sparić Radmila , Janković Ivan , Andrić Aleksandra , Pavić Aleksandra
Published: December 2020

Introduction: Influenza A H1N1 occurs worldwide sporadically or epidemically. There have been several epidemics of this disease in recent decades. Millions of people fell ill and hundreds of thousands died. The clinical picture varies from asymptomatic to lethal outcome. Older age, male gender and obesity are the most common risk factors for adverse disease. The aim of the research was to examine the clinical course and outcome of the disease of patients with pneumonia during the epidemic of influenza A H1N1 in 2019 in the Zlatibor district. Methods: Epidemiological, clinical, microbiological and radiographic data of patients with influenza A H1N1 treated at the Department of Infectious and Tropical Diseases and the Intensive Care Unit of the General Hospital of Uzice were retrogradely collected and analyzed. Virological and serological analyzes were performed at the Institute of Immunology and Virology "Torlak" in Belgrade. The diagnosis of acute respiratory distress syndrome (ARDS) was made according to the Berlin definition. Statistical analysis was performed using the Statistical Package for Social Sciences SPSS (version 16.0). Results: Out of a total of 274 patients, women accounted for 52.9%. The most common age was 61 to 70 years. 55.4% of patients had comorbidities, 61.8% of that had cardiovascular disease. C reactive protein was elevated in 79.2% of patients. Pneumonia confirmed by radiographic findings was present in 82.8% of patients, 51.5% of that had bilateral pneumonia. Four patients were pregnant, GML 5-9. Two of them had a mild clinical course of infection, one moderate with unilateral pneumonia. All three had a favorable disease outcome. A fourth pregnant woman was admitted in a severe clinical condition and was immediately referred to a tertiary health institution where the disease ended in death. 10.2% of patients were treated in the intensive care unit. Complications occurred in 23.7% of patients, ARDS in 52.3% of that. 55.9% of patients with ARDS were aged 61 to 70 years, and 58.8% were male. Among patients with ARDS, 94.1% had associated diseases, most often CVD (85.3%). C reactive protein was elevated in 85.3% of patients with ARDS. In 8.4% of patients, the disease had an unfavorable course and ended in death. Among these patients, 65.2% were women, and 73.9% were over 65 years of age. Associated diseases were present in 95.6% of these patients, cardiovascular diseases was present in 87% of that. Conclusion: During the influenza epidemic in 2019 in the Zlatibor district, pneumonia, most often bilateral, was most often in patients aged 61-70 with associated cardiovascular diseases. These were also the main risk factors for complications and adverse disease outcome. ARDS was the most common comlication and risk factor for the lethal outcome of the diseases.
Metastatic disease of melanoma malignum choroid
Authors: Knežević Snežana , Srećković Biljana , Vulović Jelena
Published: December 2020

Introduction. Choroidal melanoma is a rare form of cancer, with a total of 3-5% of the patients suffering from this type of disease. People who are more likely to suffer from the disease are of the white race, bright skin color and iris, as well as those with a genetic mutation BAP 1 and GNAQ. Studies indicate the micro-metastatic disease before the primary process is diagnosed. There is no effective therapy to prevent the development of metastases. In 90% of cases the metastases are in the liver. Metastases can occur any time after the diagnosis of melanoma, even after 40 years. The prognosis of metastatic disease is bad, the median of survival per year is 4 to 15 months. Case report. The patient had enucleation of the eye, when he was primarily treated for malignant melanoma of choroid in 2007. He also appeared regularly for checkups. Felt healthy. 9 years later, dizziness and instability occurred. After a seizure, on July 2016, echotomography and computed tomography diagnosed liver, brain metastases as well as changes in the right lung. Radio-oncology treatment deposits in the brain done with Gama knife, as well as systemic hemotherapy with Dacarbazine. Changes in the lung treated as a secondary deposit. Despite oncology and palliative treatment, the patient passed away 6 months after the diagnosis of the metastatic disease. Conclusion. It is important to point out the importance of early and accurate diagnosis and early treatment of malignant diseases. During the period of monitoring the patient, rare localizations of the metastases must be considered, as well as the possibility of their occurrence long time after the discovery of the primary malignancy. For this case report, the data obtained from extensive medical documentation was used, as well as several years of monitoring patients in Primary care.
Christian-orthodox view of the world and environmental problem
Authors: Midić Ignatije
Published: December 2020

Pollution of environment and the irreversible destruction of nature has become the way of life of the modern world. The consequences of that are obviously tragic for human life and for the survival of the entire planet Earth. This article has an aim to answer the question: what can the Orthodox Church do to stop this problem, if it cannot regain what has already been lost? To answer this question, the author first analyzes the causes of the ecological catastrophe, and then offers a theological answer to the posed problem.
World and world views at the time of the first Christians
Authors: Tili Mihael
Published: December 2020

Central places like Rome, Delphi, or Jerusalem legitimize the respective cult community by directing all conditions in the world and in history towards their center. Accordingly, the world order is maintained in the microcosm of the temple. As the "navel of the world," the temple thus serves the emergence and preservation of the cultic community. On the one hand, this makes it understandable that even the first Christians held fast to the Jerusalem Temple as a place of religious orientation. On the other hand, it explains why the Christian tradition soon identified the crucifixion site of Golgotha as the sacred world center.
Faith in ressurrection of the dead and creatio ex nihilo in 2 Macc 7
Authors: Danilović Aleksandar
Published: December 2020

The narrative of the martyrdom of a mother and seven brothers has had an enormous impact on the history of both Church and Synagogue. The cult of the Maccabean martyrs began to develop very early, so that in the fourth century at the latest, they were celebrated among the Christians. The story about them is to be found in the seventh chapter of the Second Book of Maccabees. Its canonical status has become the subject of debate in the last few centuries, both among the Orthodox and other Christians. The Synagogue rejected this book in its entirety, although it contains the oldest recorded testimony about the celebration of Hanukkah, one of the most important Jewish holidays today. However, the story of the mother and brothers remained preserved in Talmud in a certain form. Apart from the story of martyrdom, the seventh chapter hides one of the oldest, and certainly one of the most vivid descriptions of the early faith in the resurrection from the dead. In addition, the seventh chapter reveals the oldest explicitly expressed faith in God, who is the absolute Creator and who creates the world out of nothing. This idea will later become one of the central motives of Christian and Jewish cosmology.
Cosmological aspects of unity of the affirmative (kataphatic) and negative (apophatic) theological perspective
Authors: Petrović Predrag
Published: December 2020

Expressions of an affirmative and negative semantic determination are the basis of human linguistic communication. In order to communicate with one another, we must use true statements. We call true statements all those statements whose meaning is agreed upon by a large number of people. Each true statement consists of affirmative or negative statements, or both affirmative and negative statements. There are two ways of expression in the theological literature of theurgy, divine designation, and the many-faceted aspects of divine knowledge. The first way of expression is affirmative or cataphatic (gr. cataphaticή), and the second one is negative or apophatic (gr. ἀpophaticή). Although theological literature is full of problematic topics related to various aspects of affirmative and negative theological statements, we believe that for the sake of their fuller coverage it is necessary to include cosmological aspects in the discussion, since the cosmological dimension of existence is revealed as one of the basic assumptions of the theological problem of divine designation, which we find and in the theological tradition of the divine Dionysius the Areopagite. Finally, this theological aspect in contemporary theological studies of the various dimensions of affirmative and negative theology is particularly insufficient when considering its significance for the daily Christian life.
Richard of St. Victor: Person and existence
Authors: Đakovac Aleksandar
Published: December 2020

Richard of St. Victor is an important figure in the history of scholasticism. In this paper, we will analyze his idea of the person, which he developed for the needs of Triadology. The peculiarity of Richard's point of view is reflected in the attempt to establish the relationship as a key ontological definition of the person. In his thinking, Richard relies on his predecessors, primarily Tertullian, Augustine and to some extent Anselm. Despite the limitations arising from such a background, Richard's insights were a novelty in the thought of the Western Christianity, and the consequences of his teachings have never been fully grasped.
Christianity and Islam in a pluralistic society: The coexistence and challenges
Authors: Matić Zlatko
Published: December 2020

The imposed problem by social context, which directly refers to the co-existence of Christianity and Islam, articulates through simple and direct questions: Can Christians and Muslims read the signs of time together, in the world of God they share. Are there common cultural and theological paradigms, which would allow a common analysis of the signs of the historical moment? Could they interpret them together, and finally, could they join together in the process of reaction to the challenges in the purpose of transformation of this kind of world? Can the modern society be understood as a chance, not for these entities each, but as a chance for these two faiths in their eventual joint action in the field of testify of God, protological Creator and eschatological Savior? Simply, can we do it together? In order to answer all of these questions, we will consider the central issue, to what extent is Islam a challenge, and a chance to Christianity, to its word - theology, but to the modern (Christian, western) civilization? At the end, in a form of several examples we shall present our personal opinion, which concerns certain appeals of orthodox dogmatic and comparative theology, which is led by Islam, by its existence, and by its message in the pluralistic society.
Depression: Disbalance of grief and satisfaction: Two access: Saint Maximus the Confessor and Cognitive therapy
Authors: Jevtić Aleksandar
Published: December 2020

This essay is considering the problem of depression. This research is done on basis of theological access of Saint Maximus the Confessor and different points of views of cognitive therapies representatives. Relationship between feeling of grief and pleasure is in the centre of attention. Disruption of this relationship as well as different models of living both of these feelings are connected with state known as depression. In this work, some of the main research tasks are: mutual connection between grief and pleasure and the ways of their dissimulation and manifestation. It is concluded that there are not only similarities and differences, but also possibility of interdisciplinary cooperation.
Primus sine paribus - odgovor na tekst Moskovske Patrijaršije o primatu
Authors: Kisić Rade
Published: December 2020

U ovom tekstu biće predstavljen i analiziran odgovor Mitropolita Elpidofora Lambriniadisa na dokument sveštenog Sinoda Ruske Pravoslavne Crkve "Stav Moskovske Patrijaršije o prvenstvu u vaseljenskoj Crkvi". Tekst Primus sine paribus u stvari predstavlja nastavak debate o primatu u vaseljenskoj Crkvi, koja je u pravoslavnoj teologiji posebno podstaknuta usvajanjem Ravenskog dokumenta. Ključne teme u ovoj debati su pitanja da li se odnos primata i sabornosti može razmatrati u kontekstu trojičnog bogoslovlja i kako se određuje izvor primata na različitim eklisiološkim nivoima.
The fixed bed column sorption study for the nitrate removal by a cationic modified inedible pumpkin shell
Authors: Marković-Nikolić Dragana , Petković Goran , Ristić Nebojša , Bojić Danijela , Durmišević Miloš , Žerajić Stanko , Nikolić Goran
Published: December 2020

A fixed bed column was applied to remove nitrate ions from an aqueous solution using a cationic modified pumpkin shell as a sorbent. The fixed bed column performances were assessed by varying the influent nitrate concentrations (50 mg dm-3 and 100 mg dm-3) and flow rates (20 cm 3 min-1 and 40 cm 3 min-1) with 13 cm bed height of the sorbent. The obtained results showed that increase of the concentration of the initial nitrate solution affects the increase in the amount of nitrate in the effluent and reduces the breakthrough time. A higher flow rate led to the faster column exhaustion, resulting in the shortened lifespan of the column. In this study, the best nitrate removal was achieved for an initial nitrate solution of 100 mg dm-3 at the flow rate of 20 cm 3 min-1 , when a total nitrate removal of 86% is reached. The relationship between the sorption capacity of this sorbent and the varied parameters was assessed and predicted using two different theoretical breakthrough curve models: the Thomas and Yoon-Nelson models. This study confirmed that the cationic modified pumpkin shell in the fixed bed column has good potential for removing nitrate from aqueous solutions.
The identification of volatile aroma compounds from local fruit based spirits using a headspace solid-phase microextraction technique coupled with the gas chromatography-mass spectrometry
Authors: Cvetković Dragan , Stojilković Petra , Zvezdanović Jelena , Stanojević Jelena , Stanojević Ljiljana , Karabegović Ivana
Published: December 2020

The optimization of the headspace solid-phase microextraction in combination with the gas chromatography-mass spectrometry (HS-SPME-GC/MS) for the qualitative identification of the aroma compounds in fruit spirits (Williams, plum spirit, grape spirit , apricot spirit) was the subject of the presented paper. The SPME extraction conditions (temperature, time, and NaCl amount) have been varied in order to achieve the more efficient chromatographic separation of the gas mixtures, to efficiently salt-out a higher number of less volatile compounds, and to save the energy during the sample preparation. Optimal parameters were determined as: T = 40 °C; m NaCl = 2 g; dilution = 10 times. According to the results obtained, the analyzed samples of Serbian fruit spirits produced from different fruits have a comparable composition of volatile aroma compounds to whiskey. The detection and definition of specific compounds that are "fingerprint" of fruit spirits could be an efficient method of the product authentication developing.
D-optimal design of experiments and comprehensive rheological analysis in the development of natural anti-aging creams
Authors: Savić Sanela , Cekić Nebojša , Savić Saša
Published: December 2020

This work is focused on the development and evaluation of completely natural anti-aging creams, with the aid of the experimental design. Model formulations, differing in the content of emollients (10%/15%/20%) and emulsifier (1%/2%/3%) and containing the Acmella oleracea extract as a model anti-aging active were prepared by the cold process and evaluated regarding rheological behavior (con-tinuous rotational and oscillatory tests) and physical stability (dynamic-mechanical thermoanalysis-DMTA test). To study the influence of varied formulation parameters and their interaction on the critical rheological characteristics of the developed creams, a D-optimal design within the response surface method was applied. The data acquired from rheological characterization revealed favorized pseudoplastic (shear-thinning) flow behavior with the yield point, and dominating elastic behavior (storage modulus G' > loss modulus G") in both, amplitude and frequency sweeps, which together with a rather small and constant structural change obtained in the DMTA test indicated satisfying overall physical stability of formulated creams. The results of D-optimal design showed a significant individual, as well as a mutual effect of the tested formulation factors (emollient concentration, emulsifier concentration) affecting critical quality attributes (apparent viscosity, yield point, flow point, G', G", structural change) of developed anti-aging creams. Based on optimization results, the model formulation containing 20% of the emollient mixture and 2% of the emulsifier was selected as preferred in terms of required rheological properties and, thus, desired stability and quality, and it could be considered as a promising candidate worth exploring further for efficacy and in vivo skin performances.
Advanced energy management approach in food industry
Authors: Rajić Milena , Milosavljević Pedja , Maksimović Rado , Pavlović Dragan
Published: December 2020

Energy represents a key aspect that characterizes the ability of an enterprise to maintain its sustainable business. It is also considered as a key resource, while its consumption should be monitored and controlled. The standard for the energy management system used widely in industry is ISO 50001. This standard specifies the requirements for the energy management system by introducing the material and the energy flow analysis. This paper presents the application of the energy management approach to identify the energy profile of the enterprise in the food industry sector. The energy flow was identified in order to have full insight into all energy consumption users. Based on the measured and calculated results, the energy performance indicators were obtained and compared with similar processes in the food industry. The aim of the paper is to analyze the energy demand in a production enterprise, to have insight into the material and energy flows in the process in order to optimize the production process.
Toxicity of essential oils: A brief overview of bioassays
Authors: Stepić Katarina , Kostić Danijela , Ickovski Jovana , Palić Ivan , Stojanović Gordana
Published: December 2020

Since the ancient times, people have used essential oils as a cure because they have noticed their beneficial effects on the human mind and body. What they did not know was how these essential oils actually affected the human body, as well as exactly what component or more of them were responsible for the activity of a particular oil. Therefore, a lot of attention has recently been paid to the detailed identification of the constituents of essential oil and determination of the biological activity of the essential oil itself, as well as of those identified constituents. The aim of this paper is to systematize the most used, most accessible and easily feasible techniques for determining the biological activity of essential oils. For this purpose, the following tests are mentioned in this paper: fumigation, insecticidal, pediculi-cidal, nematicidal, larvicidal, ovicidal, cytotoxic and antinociception bioassay.
AX2: Type of compounds and an overview of theoretically investigated TiO2
Authors: Jovanović Dušica , Zagorac Jelena , Matović Branko , Zarubica Aleksandra
Published: December 2020

AX 2-type compounds can be ionic, covalent or molecular types of structure, which depends on the size of atoms and the polarization properties. The materials of such type of the structure have different properties that can find the application in various areas of science and industry. Titanium dioxide, as a material of AX 2-type of the structure is a wide band gap semiconductor that has been widely investigated due to its photocatalytic properties and applicability for various purposes, such as the production of solar cells, decontamination of pollutants, elimination of microorganisms, suppression of cancer cells, etc. Experimental and theoretical studies of this metal oxide can give different data on the stability of individual crystalline modifications and their transitions. This study has presented an overview of theoretically examined TiO 2 modifications and current problems that can be encountered (such as various band gap values obtained by different methods and functionals; the difference between the stability of modifications examined on ab initio level and experimentally; the character of chemical bonds and transitions at the specific temperature and pressure conditions…) and overrun by optimal corrections added in calculations.
Motivational and cognitive value of games in the teaching process
Authors: Nikolić Sanja , Saračević Muzafer , Šabotić Mirela
Published: December 2020

It has long been recognized that learning content is very useful for developing the intellectual and creative abilities of children. Modern teaching requires dynamic, diverse teaching and its adaptability to the abilities of each individual student. This implies a skillful combination of modern teaching materials, methods, forms and the choice of teaching form in each lesson. In that context, motivational games in the class have a special function. It is common knowledge of every teacher that students in classes need to be encouraged towards full engagement of cognitive abilities. This is not always easy to achieve. In every class, psychological preparation (application) is necessary to mobilize students' attention in the shortest possible period of time, prepare them for cognitive activities, whether it is preparation for the processing of new teaching contents, doing exercises or repeating old material. In all this, well selected motivational games can play a significant role. With engagement of cognitive process in solving such tasks, students can find successful solutions in a short time, and success is the best motive for further work in class.
The factors of acceptance of children with autism spectrum disorders in preschool institutions
Authors: Kojić Miroslava , Kojić-Grandić Smiljana , Markov Zagorka
Published: December 2020

The present study examines the extent to which the readiness of children and their parents influences the acceptance of children with autism spectrum disorders by their typically developed peers, in regular educational groups. A total of (N=65) of typically developed respondents, attending three preparatory groups for starting school, participated in this research. In each group, one child with an autistic spectrum disorder was included in the educational process. The goal of the study was to determine whether the readiness of typically developed children and their parents influences the peer-acceptance of children with autism spectrum disorders in regular educational groups. The first educational group (N=25) and their parents were prepared for the arrival of a child with an autism spectrum disorder by the preschool teacher. This process also included the parents of the child with an autism spectrum disorder. The cooperation between the preschool teacher and the parents was exquisite. The second educational group (N=25) and their parents were also prepared for the arrival of the child with an autism spectrum disorder, but the cooperation with the parents of the child with an autism spectrum disorder was poor. The third educational group (N=15) was not prepared for the arrival of the child with an autism spectrum disorder to the educational group. The cooperation with the parents was completely lacking. The findings of the study indicate that the child from the first educational group was accepted by its peers the most at the start and the end of the school year, compared to the children from the second and third educational groups. It can be concluded that the readiness of typically developed children and their parents has positive effects on the peer-acceptance of the child with an autism spectrum disorder. The findings indicate the need for further research that will address this topic and its possible implications in practice.