Search

There is an important novelty in biomaterials by innovative potential based on (ultra)nanocrystalline diamonds, what is almost the new result in scientific world, from the Institute of Functional Nanosystems, from Ulm University. The nanosynthetized diamonds are very new frontier application from the area biomedicine. From the other side, there is evident biocompatibility of the diamond layers, selectively improved by biomimetic 3D patterns structuring. From this point of view, graph theory approach is very inspirable new idea, already applied in some other systems, within material sciences, and electronic ceramics. By graphs, we already confirmed, also the first time in material sciences, that we can easily define the parameters values on the microstructure level between the structure constituencies grains and pores. So, now we originally apply all of this on the synthetized diamond structures. This novelty, graph applications, has the great importance in getting the additional ideas and directions for phenomena analysis of electrical and thermal conductivity grow, while electroconductivity goes down and opposite, better understanding. We already have done some analysis in this field by fractal nature approach, but here we add new methods based on very original graph theory. Part of the book series: Engineering Materials (ENG.MAT.)

Artificial neural networks (ANNs) are basically the structures that perform input–output mapping. This mapping mimics the signal processing in biological neural networks. The basic element of biological neural network is a neuron. Neurons receive input signals from other neurons or the environment, process them, and generate their output which represents the input to another neuron of the network. Neurons can change their sensitivity to input signals. Each neuron has a simple rule to process an input signal. Biological neural networks have the property that signals are processed through many parallel connections (massively parallel processing). The activity of all neurons in these parallel connections is summed and represents the output of the whole network. The main feature of biological neural networks is that changes in the sensitivity of the neurons lead to changes in the operation of the entire network. This is called adaptation and is correlated with the learning process of living organisms. In this paper, a set of artificial neural networks are used for classifying the human skin biophysical impedance data.

Data on thermally induced transformations of Mn exchanged zeolites LTA and FAU topology are presented in this paper. Thermally induced phase transformation of Mn-exchange zeolites are followed in the range from 700 to 1300?C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650?C. Prolonged heating of the intermediate product above 1100?C results directly in formation of a disorder Mn-anorthiteLTA and Mn-anorthiteFAU. The parameter of unit cell of Mn-anorthiteLTA and Mn-anorthiteFAU, in temperature range between 700 and 1300?C, was observed in space group C-1. The phase conversions in the temperature range investigated were followed by thermal, X-ray powder diffraction and FT-IR analyses

This paper is based on fundamental research to develop the interface structure around the grains and to control the layers between two grains, as a prospective media for high-level electronic parameters integrations. We performed the experiments based on nano-BaTiO3 powders with Y additives. All results on dielectric parameters on submicron level are the part of global values the same measured characteristics at the bulk samples. The original idea is to develop the new computing ways to network electronic parameters in thin layers between the grains on the way to get and to compare the values on the samples. Artificial neural networks are computing tools that map input-output data and could be applied on ceramic electronic parameters. These are developed in the manner signals are processed in biological neural networks. The signals are processed by using elements which represent artificial neurons, which have a simple function to process input signal, as well as adjustable parameter which has an influence to change output signal. The total network output presents the sum of a large number neurons outputs. This important research idea is to connect analysis results and neural networks. There is a great interest to connect all of these microcapacitances by neural network with the goal to compare the results in the standard bulk samples measurements frame and microelectronics parameters. The final result of the study was functional relation definition between consolidation parameters, voltage (U) and relative capacitance change, from the level of the bulk sample down to the grains boundaries.

The effect of Nb on the microstructure and dielectric properties of BaTiO3 ceramics was investigated. The Nb/Mn–BaTiO3 ceramics were prepared using a conventional solid-state method. The concentration of Nb varied from 0.1 to 5.0 at% but Mn was fixed at 0.05 at%. The SEM indicated that compositions of 0.1 and 0.5 at% Nb displayed a fairly uniform microstructure and homogeneous distribution of additives, with a grain size of less than 2 μm. In highly doped samples a wide range of microstructural features was observed, from homogeneous and completely fine-grained microstructure to the appearance of secondary abnormal grains with core-shell structure. The dielectric constant and the loss tangent of modified ceramics were measured as a function of temperature (20–180 °C) and frequency (100 Hz-1MHz) for different concentrations of additives. The obtained results have shown that the dielectric constant at, both, room temperature (er) and Curie temperature (ermax), decreased as the concentration of Nb5+ increased. Thus, the highest values for the dielectric constant at room temperature (er = 6648) as well as at Curie temperature (ermax = 7680) were measured for the 0.1Nb/Mn–BaTiO3 samples sintered at 1350 °C. The highly doped BaTiO3 ceramics were found to exhibit lower values of the dielectric constant and low dielectric losses at room temperature. In these samples, stable dielectric permittivity with a flat dielectric behavior over a wide temperature range is observed. The Curie constant for all series of samples decreases with an increase of dopant concentration and the highest values were measured from samples doped with 0.1 at% Nb. The effect of additives on the Curie constant change is more pronounced at higher sintering temperatures. The analysis of the critical nonlinearity exponent (γ = 1.07–1.27), for lower dopant concentrations, shows a sharp phase transformation. For samples with increased Nb content, the degree of nonlinearity γ is higher indicating a diffuse phase transformation.

In this paper, we analyze a mixture of Lognormal and Log-Logistic distribution. We estimate the parameters of the introduced distribution by using the expectation-maximization (EM) algorithm. Various phenomena in the field of medicine and economy could be modeled by this mixture. In this paper, it is used to construct new mortality model for determining the unisex premium rates in life insurance. The application of the model is illustrated in the case of Serbian population and its advantages are presented in the context of life insurance premium calculation.

Due to the increased use of yttrium in agriculture and industry, there is a growing interest in the impact of yttrium on the environment and human health. Developing novel procedures to detect and quantify species of yttrium represents an important task. In this work, we apply laser desorption/ionization-mass spectrometry (LDI-MS) to detect cluster ions of the solution of yttrium(III) chloride (YCl3) at different pH values. The density functional theory (DFT) calculations were used to reveal the energetically most favored structures of the anions and cations chosen from the LDI-MS results. Examination of the positive and negative mode LDI mass spectra of YCl3 showed the presence of the heterogeneous mononuclear and polynuclear clusters, such as [YCl(OH) (H2O)3][Formula: see text], [Y2(H2O)][Formula: see text], [Y4H2(H2O)4][Formula: see text], and [Y5O4H3][Formula: see text] (at pH 2 and 5) and [Y2Cl2(H2O)2][Formula: see text], [Y2O5(HCl)(OH)][Formula: see text], and [Y3OH3(OH)2(H2O)][Formula: see text] (at pH 2, 5, and 10). The variation in the pH solution of YCl3 slightly affects the LDI mass spectrum of these yttrium clusters. It has only been noticed that the [Y4H2(H2O)4][Formula: see text] cluster ions were not detected at pH 10. These results can become a guide in the detection of yttrium chloride by LDI-MS in real samples in different fields (ecological, food, and human).

Advanced research frontiers are extended from biophysics relations on the Earth upto the discovering any type of alive matter within the whole space. Microorganisms’ motion within the molecular biology processes integrates variety of microorgnisms functions. In continuation of our Brownian motion phenomena research, we consistently build molecular-microorganisms structures hierarchy. We recognize everywhere biomimetic similarities between the particles in alive and nonalive matter. The research data are based on real experiments, without external energy impulses. So, we develop the analysis, inspired by fractal nature Brownian motion, as recognized joint parameter between particles in alive and nonalive biophysical systems. This is also in line with advance trends in hybrid submicroelectronic integrations. The important innovation in this paper is that we introduced approximation of trajectory and error calculations, using discrete mean square approximation, what cumulatively provide much more precise biophysical systems parameters. By this paper, we continue to generate new knowledge in direction to get complex relations between the particles clusters in biophysical systems condensed matter.

The microstructures properties predicting are based on their materials characteristics. In ceramic materials, regarding higher miniaturization and integrations, the structure analysis is very important. The main contribution of this research is related to relation between perovscites ceramics electronic properties, especially BaTiO3 and NZT-ceramics and structural characteristics. We applied advanced analysis, based on fractal nature and introduced complex fractal correction in defining the very important electromagnetic parameter inductivity (L). The samples consolidation includes both, powder pressing (cold sintering) and hot sintering. The fractal characterization performs very important role from powders up to the final structures, through which exists structure influence on electro-physical and other ceramic properties. We report the experimental results of BaTiO3 and NZT-ceramics processing. Also, this is the first time that we apply complex fractal correction (influence of grains and pore surface and as well as particles Brownian motion) on fundamental thermodynamic temperature in Currie-Weiss law. This application includes the influence of Housdorff dimension (DH) from the microstructure images and connect fractal corrections in Currie-Weiss law, for relative dielectric constant ϵr and magnetic permeability μr. Through ϵr and μr, on this way, for the first time in this scientific area, we present direct relation to inductivity. This complex relation opens quit new advance understanding in structures and parameters in area of ferroelectic-magnetic applications in telecommunications, by introducing the fractals. acceptedVersion

The electrical conductivity, phase, and space group of property of the NMT substance and grain boundary of samples were approximated from complex compound by Raman spectroscopy, X-ray, SEM, TEM, and differential scanning calorimeter (DSC), samples prepared and analyzed in the laboratory in the frequency ranges from 9.76 GHz. The solid-state conventional method utilized. All the samples were tested by using XRD from 1250°C to 1550°C by increasing 50 degrees for every sample and cooling to the room temperature. The contraction of structure did not happen even at elevated temperature. The increase in Nd+ ion polarizability is 0.50 nm compared to La+ rare elements material, which is 0.60, this contributes to change of perovskite cubic. This is result of the smaller size of Nd+ 0.127 nm cation compared to La+ which increase number of dipoles despite the reduction of diploes and expands relative permittivity (εr). The single-phase material produced which shows quality factor Q×f = 60000 saturated at 10 GHz and temperature coefficient of (τf) = -77 MK-1. acceptedVersion

The electronic packaging and systems are very important topics as the limitation of miniaturization approaches in semiconductor industry. Regarding the optimal materials microstructure for these applications, we studied different alloys such as Sn-3.0Ag-0.5Cu (wt.%)/organic solderability preservative (SAC305/OSP) Cu and SAC305–0.05Ni/OSP Cu solder joints. We implemented the fractal dimension characterization and microstructure morphology reconstruction. This is the first time that we applied fractals on such alloys. The morphology reconstruction is important for predicting and designing the optimal microstructure for the advanced desirable properties these alloys. These analyzed parameters are important for the hand-held devices and systems especially for the exploitation. The fractal reconstruction was applied on the prepared microstructures with five different magnifications. The results confirmed successful application of fractals in this area of materials science considering the grains and shapes reconstructions.

Biophysical and condensed matter systems connection is of great importance nowadays due to the need for a new approach in microelectronic biodevices, biocomputers or biochips advanced development. Considering that the living and nonliving systems’ submicroparticles are identical, we can establish the biunivocally correspondent relation between these two particle systems, as a biomimetic correlation based on Brownian motion fractal nature similarities, as the integrative property. In our research, we used the experimental results of bacterial motion under the influence of energetic impulses, like music, and also some biomolecule motion data. Our goal is to define the relation between biophysical and physical particle systems, by introducing mathematical analytical forms and applying Brownian motion fractal nature characterization and fractal interpolation. This work is an advanced research in the field of new solutions for high-level microelectronic integrations, which include submicrobiosystems like part of even organic microelectronic considerations, together with some physical systems of particles in solid-state solutions as a nonorganic part. Our research is based on Brownian motion minimal joint properties within the integrated biophysical systems in the wholeness of nature.

The effects of Nb/Mn and La/Mn on the electrical properties of doped BaTiO3 ceramics were investigated in this paper. A series of Nb/Mn and La/Mn-doped BaTiO3 samples, with dopant concentrations, ranged from 0.1 up to 2 at% of La and Nb, were prepared. The Mn concentration of 0.01at% was the same in all samples. The samples have been sintered at 1300°C for two hours. SEM analysis indicated a fine-grained microstructure with grain size less than in La/Mn-BaTiO3. For the same concentration of additives, the bimodal microstructure was observed in Nb/Mn-BaTiO3. Samples with a low concentration of additives (0.1 and 0.5at%) show a higher dielectric constant value. A stable dielectric permittivity with a flat dielectric response in the transition zone is observed in high doped ceramics. Higher dielectric constant values were measured for samples doped with Nb and ranged from 1790 to 4027 at room temperature. The shift of Curie temperature towards lower temperature has been noticed in all samples. The Curie-Weiss law was used to analyze the permittivity behavior in the paraelectric region.

It is of great interest to determine the relation between biophysical and condensed matter systems, because this biomimetical approach provides new frontiers for further microelectronic circuits integrations. Molecular and submolecular particles are identical in living and nonliving organisms, which implies the possibility of considering these particles motion as the biunivocal phenomenon. Brownian motion and its fractal nature, as a general phenomenon existing within both systems, is an integrative property based on which we can establish the relation between these two systems. We used some experimental data, based on the bacterial motion experiments, regarding influence of different energy impulses on bacterial trajectories. The goal of this research is to introduce the asymptotic approaching of biophysical and condensed matter systems, based on Brownian motion fractal nature similarities, presented in mathematical analytical forms.

There is a progressing interests for polycrystalline diamonds and they have been more extensively used recently. This area has been intensively researched due to the outstanding potential of this material, and this necessitated presenting some of the latest application related to engineering in this paper. A better insight of polycrystalline diamonds properties can be achieved by intensively researching the surface structure. Samples of nanocrystalline diamonds grown by the chemical vapor deposition method are analyzed and accordingly, the focus of the research was the surface parameters and their structure. It is observed that waviness and texture are unique for any direction, their values are almost the same for the chosen directions and they vary approximately from -0.2 nm to 0.4 nm. Analyses of the parameters allowed a more detailed insight into the morphology of the surfaces of polycrystalline films. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI 172057]

Existing, the biunivocal correspondents between the fractal nature and the nature discovered by fractals is the source and meeting point from those two aspects which are similar to the thermodynamically philosophical point of view. Sometimes we can begin from the end. We are substantial part of such fractals space nature. The mathematics fractal structures world have been inspired from nature and Euclidian geometry imagined shapes, and now it is coming back to nature serving it. All our analysis are based on several experimental results. The substance of the question regarding entropy and fractals could be analyzed on different ceramics and materials in general. We have reported the results based on consolidation BaTiO3- ceramics by the standard sintering technology, performed with BaTiO3 and different additives (MnCO3, CeO2, Bi2O3, Fe2O3, CaZrO3, Nb2O5, Er2O3, Yt2O3, Ho2O3). Thermodynamic principles are very important. Beside the energy and temperature, the entropy as a measure between the order and disorder (chaos) is very important parameter. In this paper, we establish the relation between the entropy and fractal that opens new frontiers with the goal to understand and establish the order-disorder relation.

Materials science is highly significant in space program investigation, energy production and others. Therefore, designing, improving and predicting advanced material properties is a crucial necessity. The high temperature creep and corrosion resistance of Ni-based superalloys makes them important materials for turbine blades in aircraft engines and land-based power plants. The investment casting process of turbine blades is costly and time consuming, which makes process simulations a necessity. These simulations require fundamental models for the microstructure formation. In this paper, we present advanced analytical techniques in describing the microstructures obtained experimentally and analyzed on different sample’s cross-sectional images. The samples have been processed on board the International Space Station using the MSL-EML device based on electromagnetic levitation principles. We applied several aspects of fractal analysis and obtained important results regarding fractals and Hausdorff dimensions related to the surface and structural characteristics of CMSX-10 samples. Using scanning electron microscopy (SEM), Zeiss LEO 1550, we analyzed the microstructure of samples solidified in space and successfully performed the fractal reconstruction of the sample’s morphology. We extended the fractal analysis on the microscopic images based on samples solidified on earth and established new frontiers on the advanced structures prediction., publishedVersion

The Global Energy Crisis necessitated improving research into new, renewable and alternative energy sources. Due to that, our focus is on the area of some phenomena and applications where different synthetic methods and micro-structure property optimization achieved significant improvement in the electro physical properties of output materials and components. This is especially important for higher energy efficiency and electricity production (batteries and battery systems, fuel cells, and hydrogen energy).The improvement of energy storage tank capacity is one of the most important development issues in the energy sphere too. It is because of this very promising research and application area that we are expanding the knowledge on these phenomena through fractal nature analysis. So, the results obtained in the field of electrochemical energy sources, especially in electrolyte development, are taken into account the analysis of fractal nature optimization. Based on the research field of fractal material science, particularly electronic materials, we conducted research in micro-structure fractal influence in the area of electrochemistry. We investigated the consolidation parameters of Fe2O3 redox processes. The influence of activation energy, fundamental thermodynamic parameters, and also the fractal correction of electrode surface area through complex fractal dimension with recognized grains and pores, and the Brownian motion of particles is introduced. Finally, the electrochemical Butler-Volmer equation fractalization is obtained. These results practically open new frontiers in electrochemical energy processes performed through the Arrhenius equation within electrolyte bulk and electrode relations and more complete and precise energy generation.

The materials’ consolidation, especially ceramics, is very important in advanced research development and industrial technologies. Science of sintering with all incoming novelties is the base of all these processes. A very important question in all of this is how to get the more precise structure parameters within the morphology of different ceramic materials. In that sense, the advanced procedure in collecting precise data in submicro-processes is also in direction of advanced miniaturization. Our research, based on different electrophysical parameters, like relative capacitance, breakdown voltage, and [Formula: see text], has been used in neural networks and graph theory successful applications. We extended furthermore our neural network back propagation (BP) on sintering parameters’ data. Prognosed mapping we can succeed if we use the coefficients, implemented by the training procedure. In this paper, we continue to apply the novelty from the previous research, where the error is calculated as a difference between the designed and actual network output. So, the weight coefficients contribute in error generation. We used the experimental data of sintered materials’ density, measured and calculated in the bulk, and developed possibility to calculate the materials’ density inside of consolidated structures. The BP procedure here is like a tool to come down between the layers, with much more precise materials’ density, in the points on morphology, which are interesting for different microstructure developments and applications. We practically replaced the errors’ network by density values, from ceramic consolidation. Our neural networks’ application novelty is successfully applied within the experimental ceramic material density [Formula: see text] [kg/m3], confirming the direction way to implement this procedure in other density cases. There are many different mathematical tools or tools from the field of artificial intelligence that can be used in such or similar applications. We choose to use artificial neural networks because of their simplicity and their self-improvement process, through BP error control. All of this contributes to the great improvement in the whole research and science of sintering technology, which is important for collecting more efficient and faster results.

The dielectric properties of Neodymium zinc titanium oxide (NZT) and Neodymium magnesium titanium oxide (NMT) were investigated. The single-phase ceramic was synthesized at various temperatures below 1650[Formula: see text]C. The result shows that the value of temperature of resonant frequency [Formula: see text] for NMT is higher than NZT. Our findings also indicate that the rare earth materials produce high property dielectric materials, despite the fact some elements produce lower negative value of temperature of resonant frequency [Formula: see text]. By doping a compound such as CaTiO3 which has a very positive temperature of resonant frequency ([Formula: see text] ppm/[Formula: see text]C) and a very high relative permittivity [Formula: see text], it is possible to tune NZT and MNT to achieve an excellent dielectric material. This work is under consideration. The results of this scientific research could be very important for modern advance applications in microelectronic miniaturization.

The focus of this study is on the control of layers between grains by applying graph theory. We performed modification of BaTiO3 nanoparticles with Y2O3. The results of capacitance change on submicron level are the part of the measured values on the bulk samples. The original idea is to develop the new approach to use graph theory for networking of electronic parameters between the neighboring grains in order to compare the values measured on the sample, and to present them through the edges in graph between corresponding vertices. Capacitance change with DC bias was measured on bulk samples, and the modified nanoparticles showed stability up to 90 V. After using graph theory with the different number of neighboring grains and on different voltages, it has been shown that capacitance change can be successfully calculated on the layers between grains. Original calculations presented as 1D cases were performed, confirming graph application as a tool with which measured bulk results can be downsized to an appropriate intergranular level, opening the new perspectives in the area of miniaturization and micropackaging.

In the past century, the use of polymers and composites with a polymer matrix has expanded to such a level that today it is impossible to imagine life without these materials. Epoxy resin and epoxy-based composites are widely used as construction materials, due to their excellent adhesion, thermal and chemical stability. Fractal nature analysis can provide insight in morphological changes at fiber-matrix interface level, which could give direction for the processing of composites. This mathematical technique can be performed on field emission scanning electron microscopy (FESEM) images, by identifying fiber phase and pores shapes and boundaries, as well as fiber-matrix bonding at the interface. In this study, fiberglass mat was used for the reinforcement of epoxy. FESEM image of enlarged fiber after the composite fracture was used for the reconstruction of data. With the use of affine fractal regression model, software Fractal Real Finder was employed for the reconstruction of fiber shape and the determination of Hausdorff dimension. Niš, Serbia, 12-14 Sept. 2021

The goal of our research is to establish the direction of coronavirus chaotic motion to control corona dynamic by fractal nature analysis. These microorganisms attaching the different cells and organs in the human body getting very dangerous because we don’t have corona antivirus prevention and protection but also the unpredictable these viruses motion directions what resulting in very important distractions. Our idea is to develop the method and procedure to control the virus motion direction with the intention to prognose on which cells and organs could attach. We combined very rear coronavirus motion sub-microstructures images from worldwide experimental microstructure analysis. The problem of the recording this motion is from one point of view magnification, but the other side in resolution, because the virus size is minimum 10 times less than bacterizes. But all these images have been good data to resolve by time interval method and fractals, the points on the motion trajectory. We successfully defined the diagrams on the way to establish control over Brownian chaotic motion as a bridge between chaotic disorder to control disorder. This opens a very new perspective to future research to get complete control of coronavirus cases.

Donor/acceptor (La/Mn) doped BaTiO3 ceramics, sintered at different temperatures, were studied regarding their microstructure and dielectric properties as well as the dielectric response in a ferroelectric/paraelectric regime. The concentrations of La3+ as donor, ranging from 0.1 to 5.0 at% were used for doping, while a content of Mn4+ as acceptor was at 0.05 at% in all samples. The sintering temperature of codoped samples were 1290? and 1350?C. A reduction in grain size and fine-grained microstructure with average grain size from 0.5 to 2.0 mm was observed in low doped samples, whereas the abnormal growth of individual grains took place in the 2 at% and 5 at% La doped specimens. The dielectric properties of these samples were investigated as a function of frequency (100Hz - 20 kHz) and temperature (20-180?C). The measured results suggested that both the dielectric constants of the ceramics (er at room temperature and ermax at the Curie temperature) decreased as the concentration of La3+ increased. The dielectric permittivity was in the range of 944 to 3200. For samples doped with 0.1 at% La and sintered at 1350?C, the highest dielectric constant value at room temperature (er= 3200) and Curie temperature (er= 5000) were measured. For all measured samples the dissipation factor was less than 0.09. With an increase in La contents, dielectric measurements exhibited shift in the Curie temperature (Tc) towards the low temperature. Using the Curie-Weiss and the modified Curie-Weiss law, Curie's constant C was calculated as well as the parameterg, which describes the deviation from the linear dependence er of T above the phase transformation temperature. The calculated values for g ranged from 1.01 to 1.43. These values indicate a sharp phase transformation in lowdoped and diffuse phase transformation in highly La doped samples. The phase transition was reflected in the values of C that started to decrease with increasing dopant content.

Mineralogical and chemical composition of mortar from the floor, ceiling and wall of Stibadium B, from the archaeological site of Mediana (Serbia) have been analysed using ICP-OES, FТIR and XRD-spectroscopy and chemical analysis. The results show that hydraulic lime mortar was used with crushed bricks as artificial puzzolanic aggregate. Large contribution of silicon- and aluminum-oxides, indicate the presence of quartz and phyllosilicate minerals derived from the aggregate, river sand and crushed bricks. Also, high content of Pb and Cu was observed in investigated samples. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 176008 and Grant no. TR36017]

The microstructure characteristic and dielectric properties of doped BaTiO 3 -ceramics were investigated in the light of the Clausius–Mossotti relation (CMR) which incorporates both the Curie and Curie–Weiss Laws. The samples of doped BaTiO 3 ceramics were prepared using conventional solid state procedure and sintered from 1290 °C to 1320 °C. Microstructural and compositional studies were performed by SEM equipped with EDS system. The Clausius–Mossotti relation is used to clarify the influence of dopant on the dielectric properties and BaTiO 3 phase transformation. Curie parameters (C, Tc) were calculated by using a Curie–Weiss law. Also, a new approach on correlation between microstructure and dielectric properties of doped BaTiO 3 based on fractal nature analysis (grains shapes, pores and intergranular contacts) have been developed, by using fractals in microstructure configurations reconstruction. This includes reconstruction of grain surface i.e. pore surface as tensor product of appropriate fractal curves. Particles chaotic motion trajectories is considered as Brownian motion which is then linearized in fractal manner. Fractality of grain surface, pore surface and particle motion introduce three fractal factors. Our hypothesis is that working temperature of BaTiO 3 -ceramics must be influenced by ceramics material fractality; these three fractality factors, appear as a correction of theoretic temperature appearing in Clausius–Mossotti relation i.e. Curie–Weiss law. © 2018, © 2018 Taylor & Francis Group, LLC.

BaTiO3-ceramics is a porous material made out of grains and pores. Such a structure is best explained by fractal nature approach. There is a strong porosity influence on microelectronic properties,...

This paper is focused on the research an improved version of the Boltzmann-Poisson model for BaTiO3-ceramics. In the approximation of one relaxation time, for constant external electrical field, this approach included correct quadratic relation for varistor effect in the case of the Heywang model. Within meso-kinetics, quantum corrected Boltzmann-Poisson model, contains space-time correlations for the probability distribution density function f(r, k, t), lead to correct fractional relaxation velocity description. These new results corresponds to our other research based on electronic particles Brownian motion within its fractal nature.

This paper presents mineralogical and crystallographic characterization of the zeolitic tuff from the Novakovic deposit, Republic of Bosnia and Herzegovina. The zeolitic tuff is of a whitish color composed of Ca-clinoptilolite and an amorphous phase (volcanic glass and amorphous SiO2). The zeolitic tuff was analyzed by X-ray diffraction of the polycrystalline sample (XRPD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), and differential thermal and thermo- gravimetric (DTA/DTG) methods. According to the results obtained, it can be concluded that the studied zeolitic tuff is composed of Heu-type minerals. Based on the chemical analysis, thermal treatment and XRPD analysis it was determined that this is a mineral Ca-clinoptilolite. Thermal analysis in the temperature range from 300 up to 700?C showed that the examined zeolite minerals from the Novakovic deposit are stable up to the temperature of 600?C. The crystal structure of Ca-clinoptilolite has been refined in the centrosymmetric space group C2/m (S.G. 12) with disordered distribution of Al and Si in the tetrahedral framework. The unit-cell parameters are as follows: a = 17.662 ?, b = 17.874 ?, c = 7.402 ?, ? = 116.32? and V = 2122.73 ?3. The basic structural motif is represented by four channels. Three channels are composed of eight-membered rings, and one of ten-membered rings. The ten-membered (channel A) and one eight-membered channel (B) are parallel to the crystallographic axis c, and the other eight-membered channel is parallel to the a-axis. Ca-clinoptilolite comprises approximately 90 % of the studied zeolite tuff while the rest 10 % is the amorphous phase. The overall cation exchange capacity (CEC) amounts to 187 mmolM+/100g, and calcium represents the most abundant cation in the studied sample. The atomic ratios of Si/Al, Na+/(Na++K+), and Ca2+/(Ca2++Mg2+) are as follows: 4.36, 0.14, and 0.55, respectively. The zeolite tuff is both thermally and structurally stable and has applications in various areas of industry and agriculture.

Historically, although the first indications for the use of lasers in general were in dentistry, coming as a relief from the sound of the drill and mechanical contacts, it still seems somewhat that the entry in various ways of lasers in dentistry has been slower. This is somewhat true for the situation at the continents (e.g. USA much later approved the application relative to Europe). This paper analyzes the potential and existing applications of lasers in dentistry in a wide range of existing types, including interaction with dental tissues, in terms of surgical applications, on living tissue, the prosthetic area of applications and therapeutic doses. There is another special feature that can be recognized is the precise determination of the color of the material (teeth and prosthetics) and in general the determination of the composition of the material including classic, but also modern laser techniques (LIBS, complimentary techniques, tooth tissue, bone) and especially in the case of the first Q switch systems related to pain reduction, because the short pulse favors the intervention rate (ns, ps and fs). Special attention should be paid to modeling of interaction and analysis with the appropriate software support.

This research is focused on further developing of application and use of graph theory in order to describe relations between grains and to establish control over layers. We used functionalized BaTiO3 nanoparticles coated with Yttrium-based salt. The capacitance change results on super-microstructure levels are the part of the measured values on the bulk samples. The new idea is graph theory application for determination of electronic parameters distribution at the grain boundary and to compare them with the bulk measured values. We present them with vertices in graph, corresponding with grains, connected with edges. Capacitance change with applied voltage was measured on samples sintered in air and nitrogen, up to 100 V. Using graph theory, it has been shown that capacitance change can be successfully calculated on the layers between grains. Within the idea how to get parameters values at microlevel between the grains and pores, mathematical tool can be developed. Besides previously described 1D case, some original calculations for 2D cases were performed in this study, proving successful graph theory use for the calculation of values at nanolevel, leading to a further minituarization in micropackaging. This is the peer reviewed version of the article: Randjelović, B.M., Mitić, V.V., Ribar, S., Lu, C.-A., Radovic, I., Stajcic, A., Novakovic, I., Vlahovic, B., 2020. Ceramics, materials, microelectronics and graph theory new frontiers. Mod. Phys. Lett. B 34, 2150159. [https://doi.org/10.1142/S0217984921501591] Published version: [https://hdl.handle.net/21.15107/rcub_dais_10032]

Nanomaterials form the main thrust for modern day technological and industrial applications, including but not limited to, super-capacitors, membranes, batteries, filters, sensors, tissue engineering, wound dressing, protecting vesture, reinforcement in composite materials, etc. Ceramic nanofibers are at the forefront of these materials due to their high surface area and tunable nano structures and porosity. However, obtaining nanofibers with a well-developed uniform crystallinity and a perfect morphology is a challenging task. Among various techniques utilized for preparation of nanofibers centrifugal jet spinning covets merits due to its high efficiency production rate, cost adequacy and operational safety. In the present manuscript we report preparation of TiO2 nanofibers by Sol–Gel Course with Centrifugal Jet Spinning using tetrabutyl titanate as main organic titanium precursor. Herein we demonstrate that a well-developed crystallinity and a perfect morphology of TiO2, from Nano to micro-scales, can be achieved after decomposition of polymer and removal of carbon. Effect of various factors such as PVP content, speed of rotation, humidity and heat treatment on the fiber growth was investigated. Effect of variation in soaking time and different temperatures on the TiO2 nanofiber grain growth was also investigated. Phase structure of TiO2 nanofibers was characterized by X-ray diffraction (XRD). Microstructure of the nanofibers was analyzed using Scanning Electron Microscopic (SEM) studies and Transmission Electron Microscope (TEM) studies. Kinetic exponents of grain growth were likewise acquired by with the help of an image processing software. Outcomes of our investigations show that crystallinity and morphology of grains of fibers are highly sensitive to temperature and soaking time. Image analysis demonstrates that sintering temperature greatly affects the crystallinity and grain size of the nanofibers over 700 °C.

The main goal of our research is to find the connection between micro particles and microorganisms motion in the Nature, considered as Brownian’s Motion within the fractal’s nature. For ceramics and generally material science it is important to clarify the particles motion and other phenomena, especially for grains and pores. Our idea is to establish control over the relation order–disorder on particle motion and their collision effects by Brownian motion phenomena in the frame of fractal nature matter. We performed some experiments and got interesting results based on microorganism motion initiated by different outer energetic impulses. This is practically the idea of biomimetic correlation between particles and microorganisms Worlds, what is very original and leads towards biunivocal different phenomena’s understanding. Another idea is to establish some controlling effects for electro ceramic particle motion in chemical-materials sciences consolidation by some phenomena in the nature. These important research directions open new frontiers with very specific reflections for future of microelectronics materials. This is the peer-reviewed version of the article: Mitic, V., Lazovic, G., Milosevic, D., Lu, C.-A., Manojlovic, J., Tsay, S.-C., Kruchinin, S., Vlahovic, B., 2020. Brownian motion and fractal nature. Mod. Phys. Lett. B 34, 2040061. [https://doi.org/10.1142/S0217984920400618]

The BaTiO3 ceramics applications based on electronic properties have very high gradient scientific and industrial-technological interests. Our scientific research has been based on nano BaTiO3 modified with Yttrium based organometallic salt (MOD-Y). The samples have been consolidated at a sintering temperature of 1350 &deg, C. Within the study, the new frontiers for different electronic properties between the layers of BaTiO3 grains have been introduced. The research target was grain boundary investigations and the influence on dielectric properties. After scanning electron microscopy and dielectric measurements, it has been established that modified BaTiO3 samples with larger grains showed a better compact state that led to a higher dielectric constant value. DC bias stability was also investigated and showed a connection between the grain size and capacitance stability. Analyses of functions that could approximate experimental curves were successfully employed. Practical application of fractal corrections was performed, based on surface (&alpha, s) and pore size (&alpha, p) corrections, which resulted in obtainment of the relation between the capacitance and Curie temperature. Successful introduction of fractal corrections for capacitance-Curie temperature dependence for a set of experimental data is an important step towards further miniaturization of intergranular capacitors.

The grain size and the ferroelectric morphology are the two most important factors in the research and development of advanced dielectric devices. It is important to synthesize nanostructures in order to achieve optimal grain size and inhibit grain growth while controlling the sintering parameters. It is also important to find new methods to study the grain growth during densification. BaTiO3 films were successfully obtained via the sol-gel spin coating method. In this paper, we report the deposition of nanostructured BaTiO3 thin film by spin coating of sol-gel precursors. The densification, grain growth and microstructure evolution have been studied. Moreover, a novel physical and mathematical fractal analysis have been applied successfully to the densification and nano grain growth of BaTiO3 thin film. The discrepancy between the fractal dimension and the grain growth with increasing temperatures and soaking time are presented and discussed. This is the peer-reviewed version of the article: Aminirastabi, H., Xue, H., Mitić, V.V., Lazović, G., Ji, G., Peng, D., 2020. Novel fractal analysis of nanograin growth in BaTiO3 thin film. Materials Chemistry and Physics 239, 122261. [https://doi.org/10.1016/j.matchemphys.2019.122261] Published version: [https://hdl.handle.net/21.15107/rcub_dais_6886]

Nowadays, there is a very high importance of composite research and variety of their applications in the modern world. In that sense, we researched hollow glass capillaries filled with dissolved Grubbs catalyst (GC) and dicyclopentadiene (DCPD) were incorporated into a fiber-reinforced epoxy with the aim of improving the flow of healing agents to the crack site. The morphological investigation of the crack site was performed using field emission scanning electron microscopy (FESEM), showing the difference between the samples depending on the used solvent. The software analysis of sample photographs has been performed by calculating the fractured/healed surface area of the samples, revealing that approximately 20% of the volume was affected by the impact. Fourier transform infrared spectroscopy (FTIR) revealed that poly (dicyclopentadiene) (PDCPD) formed at the healed interface. However, the FTIR investigation of catalyst stability in different solvents showed structural changes in GC and partial deactivation. The mechanical tests of the samples showed that a recovery of 60% after 24 h at room temperature could be achieved through the use of a solvent and very low concentration of GC. The performed research results are a good base to develop the model for predicting the processes and morphology, with the goal to design the final mechanical and in the future, thermal, properties in advance. This opens a new direction for future research in the field of composite healing. © 2020 Elsevier B.V.

The effect of rare earth ions on dielectric permittivity, dielectric losses and microstructure of barium titanate ceramics doped with Ho, Er and Yb at the concentrations of 0.05 wt% to 1.0 wt% was investigated. The doped BaTiO 3 were obtained by solid-state sintering reaction at a temperature of 1320°C in air atmosphere. The electrical properties were measured in the temperature interval from 30°C to 180°C at different frequencies. The results of electrical investigation showed that samples doped with a low additives concentration, with a spherical and large grains, have high dielectric constant value. e r at Curie temperature is 4250, 3828 and 3011 for 0.05 wt% Ho, Er and Yb respectively. By increasing dopant concentration and decreasing grain size, the dielectric permittivity value decreases. All investigated samples have low values of dielectric losses ranged from 0.01 to 0.09. Also, samples with a low concentration of additives follow Curie-Weiss‘s law. The Curie temperature of doped samples is slightly lower than Curie temperature of the undoped ceramics and it is 126-128 °C. The Curie constant $C$ for all examined samples increases with increasing dopant concentration, so that the highest values were measured for the samples doped with 1.0 wt% of the additive.

Interlayer transport of charges and carriers of 2D nanomaterials is a critical parameter that governs the material and device performance in energy storage applications. Inspired by multilevel natural bamboo-membrane with ultrafast water and electrolyte transport properties to support its super-rapid growth rate, 2D–2D multilevel heterostructured graphene-based membranes with tailored gradient interlayer channels are rationally designed for achieving ultrafast interlayer ion transport. The bioinspired heterostructured membranes possess multilevel interlayer spacing distributions, where the closely packed layers with sub-nanosized interlayer space provide ultrafast confined interlayer ion transport, while the loosely stacked outer layers consisting of open channels with large distances up to few micrometres are favorable for rapid wetting and penetration of liquid electrolytes. The combination of advantages of large-size open channels and nanosized confined channels offers ultrafast electrolyte wetting and permeation and interlayer ion transport and provide the devices with superior volumetric capacity as free-standing electrodes for rechargeable batteries.

Hydroxyapatite scaffold is a type of bio-ceramic. Its cellular design has similarities with the morphologies in nature. Therefore, it is very important to control the structure, especially the porosity, as one of the main features for bio-ceramics applications. According to some literature, freeze casting can form the shape of dendrites and remain a foam structure after ice sublimation. Ice nucleation became more heterogeneous with the aid of printing materials during freeze casting. This procedure can even improve the issue of crack formation. In this paper, we studied the mechanical properties of hydroxyapatite scaffold. We also analyzed the porosity by fractal nature characterization, and successfully reconstructed pore shape, which is important for predicting ceramic morphology. We applied SEM analysis on bio-ceramic samples, at four different magnifications for the same pore structure. This is important for fractal analysis and pores reconstruction. We calculated the fractal dimensions based on measurements. In this way, we completed the fractal characterization of porosity and confirmed possibilities for successful porous shapes reconstruction. In this paper, we confirmed, for the first time, that fractal nature can be successfully applied in the area of porous bio-ceramics.

After pioneering attempts for the introduction of graph theory in the field of ceramics and microstructures, where 1D and 2D graphs were used, in this paper we applied 3D graphs for the breakdown voltage calculation in BaTiO3 sample with some predefined constraints. We have described the relations between grains in the sample and established a mathematical approach for the calculation of breakdown voltage using experimental results. As a result, we introduced mapping between the property of sample and grain structure, then between the grain structure and mathematical graph, using various crystal structures. The main idea was to apply 3D graph theory for the distribution of electronic parameters between the neighboring grains. With this study, we successfully confirmed the possibilities for applications of graphs as a tool for the determination of properties even at the intergranular level.

In this study, the electrical resistivity (ρ) and PTC effect of Er doped BaTiO3 ceramics are investigated. The concentrations of Er2O3 in the doped samples vary from 0.01 to 1.0 at% Er. The samples are prepared by the conventional solid state reaction, and sintered at 1320° and 1350°C in air atmosphere for 4 hours. The SEM analysis shows that all of measured samples are characterized by polygonal grains. The uniform and homogeneous microstructure with grain sizes from 20 to 45μm is the main characteristic of the low doped samples (0.01 and 0.1 at% Er). For the samples doped with the higher dopant concentration (0.5 and 1.0 at%) the average grains sizes have been ranged from 5 to 10 μm. The electrical resistivity is measured in the temperature range from 25°C to 170°C, at frequencies 1 kHz, 10 kHz and 100 kHz. The electrical resistivity values, measured at frequency of 1 kHz and room temperature, have been ranged from 1.62•104 Ωcm to 4.24∙104 Ωcm, for samples sintered at 1320°C and from 1.43•104 Ωcm to 1.94∙104 Ωcm, for samples sintered at 1350°C. A nearly flat and stable electrical resistivity-temperature response is characteristic for all samples at the temperature range from 25°C to 120°C. Above this temperature, the electrical resistivity increases rapidly. At 170°C the value of electrical resistivity is ranged 9.84•104 Ωcm -1.62•105 Ωcm, for Tsin=1320°C, and 6.11•104 Ωcm 1.32•105 Ωcm, for Tsin=1350°C. The electrical resistivity decreases with concentration increment up to 0.5 at%, while above 0.5 at% it increases. Also, with increasing frequency, ρ decreases for a few orders of magnitude. [172057: Directed synthesis, structure and properties of multifunctional materials]

Fluctuation of wind speed affects wind energy systems since the potential wind power is proportional the cube of wind speed. Hence precise prediction of wind speed is very important to improve the performances of the systems. Due to unstable behavior of the wind speed above different terrains, in this study fractal characteristics of the wind speed series were analyzed. According to the self-similarity characteristic and the scale invariance, the fractal extrapolate interpolation prediction can be performed by extending the fractal characteristic from internal interval to external interval. Afterward neuro-fuzzy technique was applied to the fractal data because of high nonlinearity of the data. The neuro-fuzzy approach was used to detect the most important variables which affect the wind speed according to the fractal dimensions. The main goal was to investigate the influence of terrain roughness length and different heights of the wind speed on the wind speed prediction.