Recent Advances in Technology Research and Education

Gradient coatings were obtained as a result of deposition from the combined titanium plasma fluxes of a DC arc discharge and the flow of carbon ions formed by sputtering a graphite target with an impulse arc discharge. Structure and surface morphology of the coatings were analyzed by Raman spectroscopy and AFM. Mechanical properties were studied by friction (a “sphere-plane” method) and microhardness test (AFFRI DM8 test machine with a Knoop style diamond tip). The dependence between the carbon concentration in the depth of the studied films and their microhardness has been found out. Raman spectroscopy showed that films with high contents of the sp3 phase are formed, the presence of titanium atoms leads to a decrease the size of the carbon sp2 cluster, nitrogen conducts to an increase in the degree of disordering of s2 carbon clusters. It is established that the parameters of friction and wear depend on the structure of the gradient films.

The authors have been developing the method to recover the material of sintered carbide in electrochemical machining (ECM). The ECM performance is affected by the change in the electrolyte ingredient when the sintered carbide material is dissolved into the electrolyte. Besides, tungsten and cobalt are costly rare metals. In this report, the feasibility of a process on recovery of tungsten and cobalt by changing soluble substances into insoluble ones was investigated, in which process tungsten as calcium tungstate and cobalt as cobalt hydrate. It was found that the tungsten and cobalt compounds could be recovered by the proposed processes.

Establishment of effective tritium removal method was one of important issues for the development of fusion reactor from the view of fuel recycle and safe operation. The deuterium (D) removal efficiency in tungsten (W) by energetic hydrogen (H) ions under room temperature and baking under 623 K were studied by thermal desorption spectroscopy (TDS). Iron (Fe) damaged W with various damage level by 6 MeV Fe2+ was adopted to simulate neutron irradiation damages. To understand the D removal behavior, the desorption of D₂ was measured in-situ by a quadrupole mass spectrometer (QMS) during H₂+ implantation and baking. The in-situ results showed that the desorption of D₂ started after H₂+ implantation and became slowly with the increment of H₂+ implantation time. After H₂+ implantation, part of D trapped by dislocation loops, vacancy clusters and voids could be removed by hydrogen isotope exchange. However, the removal efficiency by hydrogen isotope exchange decrease obviously as the presence of irradiation damages. The D trapped by dislocation loops and vacancy clusters can be removed by baking with high efficiency. It is worth to note that the D trapped by voids cannot be removed by baking leading to the lower D removal efficiency for W with high damage level.

The investigation of new functional materials (ceramics) based on cerium (IV) oxides is a promising field of scientific research. A wide application in the industry received composite materials based on CeO₂–Gd₂O₃ and CeO₂–Sm₂O₃.Thin ceramic films were formed on the basis of CeO₂ with 10 mol% Gd₂O₃ (GDC10), CeO₂ with 20 mol% Gd₂O₃ (GDC20), CeO₂ with 15 mol% Sm₂O₃ (SDC15), CeO₂ with 20 mol% Sm₂O₃ (SDC20) using e-beam technique in this work. The deposition rate and temperature of the substrate had influence on the formed doped cerium oxide GDC10, GDC20, SDC15, SDC20 thin films structure. Sm and Gd doped cerium oxide thin films were deposited on SiO₂, Alloy 600 (Fe-Ni-Cr), Si (111), Si (100) and Al₂O₃ substrates. Investigations of the formed thin films were carried out using a Scanning electron microscope (SEM), Electron dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy. It has been established that the cerium oxide based ceramic retains the crystalline structure, regardless of the concentration of the dopant and used substrate type. The most dominant crystallographic orientation of formed thin films was cubic (111). Raman spectroscopy measurements showed the peak (465 cm−1) of pure ceria corresponding to F_2g vibrational mode. First-order peaks, inherent to cerium oxide, were shifted to a region of lower wavenumbers and depend on dopant concentration. The peaks for all formed thin films were similar to each other in form but the position, half width and their intensity varied depending on the dopant concentration. Raman peaks position at 550 cm−1 and 600 cm−1 could be explained as change of oxygen vacancy amount due to the cerium transition between oxidized and reduced forms.

This paper presents a method of three-dimensional imaging of dopants in wide band gap semiconductors by two-photon fluorescence microscopy. Tightly focused light beam radiated by two titanium-doped sapphire laser is used to obtain two-photon excitation of selected area of the semiconductor sample. Photoluminescence intensity of a specific spectral range is selected by optical band pass filters and measured by photomultiplier tube. Reconstruction of specimen image is done by scanning the volume of interest by piezoelectric positioning stage and measuring the spectrally resolved photoluminescence intensity at each point. The developed two-photon microscope was able to image the whole doped area, which was beyond capabilities of market-available confocal microscope. Additionally, the study found, that the doped volume is immersed below the surface of the semiconductor material, which was impossible to image with confocal microscope. Additionally, the study found, that the doped volume is immersed below the surface of the semiconductor material, which was impossible to image with confocal microscope.

The present work aims to design and study novel functional materials with multiferroic properties required in electric applications, such as magnetic and magnetoresistive sensors, actuators, microwave electronic devices, phase shifters, mechanical actuators etc. Complex oxides BiFeO₃ for analysis of its magnetic properties were synthesized by sol-gel method as powders. The size, shape and degree of crystallinity of the nanoparticles formed by sol-gel method can be controlled by varying the temperature and the ratio of the concentrations of the initial reactants and the stabilizer. To stop the growth of particles in all cases, it is usually enough to cool quickly the reaction mixture. To isolate the nanoparticles, the precipitating solvent is added, which mixes with the reaction system, but poorly dissolves the “protective shells” of the nanoparticles and, therefore, destabilizes the suspension. As a result, the nanoparticles precipitate as powder, which can be separated by centrifugation. The sol-gel method makes it possible to obtain practically monodisperse nanoparticles of various metals oxides.

TiO₂ is well known for its photocatalytic properties and wide range of applications. However, the efficiency of amorphous TiO₂ as photocatalyst is low and deposition of crystal TiO₂ phases is strict to deposition parameters. The TiO₂ phase dependence on temperature, total pressure (p_tot) and oxygen partial pressure and total pressure (p_O2/p_tot [%]) ratio and how this affect growth rate has been studied in this work, TiO₂ thin films were deposited via magnetron sputtering technique using different deposition parameters in order to get TiO₂ either pure anatase or rutile phase. Crystallographic structure and morphology of deposited thin films were analyzed by XRD and SEM/EDS. TiO₂ phase strongly depends on substrate temperature during the deposition of thin films, total pressure and p_O2/p_tot ratio. Analysis shows that TiO₂ anatase phase depends more on substrate temperature than p_O2/p_tot, while TiO₂ rutile phase in reverse, noting that it has better stability at high temperatures compared to anatase.

Spectroscopic performance of the Ni/CdTe/Au Schottky diode X/γ-ray detectors was examined by measurements of 137Cs isotope spectra at different bias voltages and operation time. Both the Schottky (Ni-CdTe) and near Ohmic (Au-CdTe) contacts were formed on the opposite sides (10 × 10 mm2) of high resistivity CdTe(111) crystals after preliminary chemical etching and Ar-ion bombardment with different parameters. The detectors had low reverse dark current density (4–6 nA/cm2 and 8–12 nA/cm2 at bias of 500 V and 1000 V, respectively) and showed quite high energy resolution (2–4%@662 keV) at room temperature. The optimal bias voltage ranges for the Ni/CdTe/Au detectors were determined to achieve sufficiently high detection efficiency and energy resolution. These parameters were changing by 30–50% for the detectors biased and subjected to γ-ray radiation during several hours that evidenced quite low degradation. The detector spectroscopic parameters can be recovered by turning off the bias for seconds and turned on it again to continue measurements.

Optical properties of non-treated silicon plates and Si plates modified by femtosecond laser irradiation have been investigated by ellipsometry. The samples of the nanostructured silicon as isolated cells were formed on the single-crystal silicon wafers by a method of the laser ablation. Laser beam scanning modes provide the synthesis of nanostructured silicon dioxide particles or silicon nanoparticles. It was established that the principal angle of incidence for the nanostructured silicon is significantly reduced in comparison to the one for monocrystalline silicon wafers of 12–21°. Moreover, the essential difference between the values of the cosΔ and tgΨ for two mutually perpendicular directions in own plane of the cell when ones were measured at single taken angle of light incidence $$ \varphi $$φ = 53° was observed. Besides, for single cell it was found that the difference between the significances of the principal angle of incidence and ellipsometric parameter Ψ for two mutually perpendicular directions in own plane of the isolated cell of the nanostructured silicon is essential and equal to about 9° and more than 15° respectively. This means that the formed silicon nanostructures possess great optical anisotropy as a result of deformation influence of laser ablation and appearance of elastic stresses within the surface layer of the nanostructured silicon. The optical anisotropy was not found for silicon areas located between the cells of the nanostructured silicon.

The X-ray photoelectron spectroscopy (XPS) with 650 eV synchro-tron radiation was employed to study the In/CdTe diode detector structures formed by laser-induced doping and subjected to multiple Ar-ion etching from the In-coated side. The dependences of the peak areas in the high-resolution Cd 3d and In 3d XPS spectra on the etching number demonstrated the presence of Cd atoms in the In film and In dopant atoms in the CdTe near the In/CdTe inter-face. This was attributed to ultrafast mutual diffusion under laser action. The XPS results were direct evidence of incorporation of In dopant atoms into the surface region of the CdTe crystal and penetration of Cd atoms into the In film.

Cellular structures with triply periodic minimal surface (TPMS) topology are studied in current research work. Previously, it was shown that materials with TPMS topology have a potential as a lightweight material in energy-absorbing systems that can be used in various applications such as protective layer landing pods of spacecraft. In this work Schwartz primitive structure was chosen to study the influence of scale factor, unit number on mechanical properties. Samples were made by selective laser sintering process of polyamide powder and tested on Walter+bai ag LFM − 400 kN machine.

Both of radiation-induced damages and helium (He) existence effects on deuterium (D) retention in tungsten (W) by D plasma exposure were evaluated using high flux divertor plasma exposure device, called Compact Divertor Plasma Simulator (CDPS). The results were compared with 3 keV D₂+ implanted W with low flux and fluence. The thermal desorption spectra were consisted of three desorption stages at 400, 600, 780 K. Comparing to the undamaged W, the D desorption stages were shifted towards higher temperature side and the values of D retention increased. It can be said that the formation of stable trapping sites by damage introduction enhances the D trapping in the damaged W. For He+ irradiation, D desorption at lower temperature was enhanced, due to the formation of dense dislocation loops. In case of sequential Fe2+ and He+ implantation, D desorption at higher temperature was reduced, comparing to that for only Fe2+ damaged W. These facts show that the accumulation of He near surface region reduces D diffusion toward bulk, leading to the reduction of D trapping by voids.

Exposure of water to atmospheric discharge plasma in air determines generation of long-living reactive species as hydrogen peroxide H₂O₂, nitrites NO₂- and nitrates NO₃-. The water thus treated is called plasma activated water and have applications in medicine and agriculture. In the present work, surface DBD micro plasma working in air at atmospheric pressure is used to treat a small amount of deionized water. The surface DBD plasma was generated on the dielectric surface of a device formed by two silver electrodes deposited on the two sides of a thin glass plate. The device was powered by a high voltage amplifier that applied on the electrodes a sinusoidal waveform voltage at a frequency around 13 kHz and peak to peak amplitude of 4 kV. Time series of current intensity and voltage values were acquired to determine the power injected into the surface DBD micro plasma. Optical emission spectroscopy was used to get information on reactive species generated by micro plasma in the gaseous phase. The reactive species generated in water during the discharge-on and discharge-off periods were investigated by means of UV absorption spectroscopy. The measurements showed that the concentration of these reactive species rise not only during the discharge-on time, but also during discharge-off time for a few tenths of minutes. This observation points towards an optimization scheme of the treatment, which uses discharge on/off steps.

The objective of the paper is to create on the basis of omega-shaped bianisotropic elements new absorbing metamaterials and coatings that do not have a reflecting base and are “invisible” on the irradiated side.

Optical properties of zirconium-based amorphous alloys that were subjected to deuterium plasma treatment have been investigated by the multiple-angle-of-incidence single-wavelength and spectral ellipsometry in a spectral range of 0.5–3.5 eV. After bombardment by ions of deuterium plasma of the samples the increase in the intensity of absorption within the spectra of optical conductivity in the indicated spectral range was found. Such behavior of the optical properties can be explained by deuterium plasma ions sputtering of a subsurface layer, and by modification of the electronic properties of a near-surface layer due to deuterium implantation. The optical anisotropy of the samples both in the initial and after treatment in the deuterium plasma was not observed being inherent for amorphous surface layer structures. It has been found that the treatment of mirror-like surfaces by the deuterium plasma increases the roughness of the surface of Zr₅₇Cu_15.4Al₁₀Ni_12.6Nb₅ alloy mirror sample investigated.

Finely dispersed (particle size less than 100 nm) NaYF₄:Yb3+,Er3+ and YF₃:Yb3+,Er3+ phosphors are synthesized using a hydrothermal method. YF₃:Yb3+,Er3+ phosphor is found to be mostly appropriate for IR radiation based photodynamic therapy (PDT). The efficiency of infrared laser stimulated generation of singlet (active) oxygen by a drug composition containing YF₃:Yb3+,Er3+ phosphor and “Radachlorin” photosensitizer is characterized.

In this work, we discuss the applicability of photon-coupled, photoswitchable proteins in multi-valued computing circuits. The proposed operational principle is based on photoswitchable proteins, capable of switching between more than two forms when subjected to light with well-defined frequencies. The molecules must be able to emit light with specific frequencies, determined by their forms (e.g. fluorescent photoswitchable proteins) in order to enable photo-coupling between neighboring proteins. According to our considerations such protein arrangements are potentially suitable for the realization of low power-consuming, terahertz-frequency, nanoscale, multiple-valued logic circuits.

3D printing technologies became an integral part of the medical environment due to their ability to produce relevant copies of human organs and tissues. This feature can be used by developing of radiotherapy/radiology phantoms for patient dose verification thus providing an excellent possibility for individualization of irradiation procedure.X-ray attenuation properties of four different 3D printing materials (PLA, ASA, PETG and HIPS) thought for phantom construction. Irradiation of samples printed in ZORTRAX300 3D printer was performed in X-ray therapy unit GULMAY D3225; peak voltage of 120 kV was applied. Multipurpose semiconductor detector BARACUDA was used for the assessment of X-ray attenuation in irradiated samples. Experimental results were verified with the results obtained using XCOM data based simulations. It was found, that X-ray attenuation properties of investigated materials were similar to those estimated for thyroid gland, brain, muscle and skin, however differed significantly from attenuation properties in bone and teeth, which are present in the head and neck region and play an important role in attenuation of X-rays in this anatomic region during irradiation procedure.

Due to its outstanding photon attenuation features lead (Pb) is the most popular material which is used for radiation shielding and for radiation protection of individuals against ionizing radiation. However, Pb is very toxic and can cause serious health problems. Also recycling of lead containing materials is relative complicated. In order to overcome Pb related problems, researchers are looking for lead free materials possessing similar photon attenuation properties as lead and that can be used for the development and fabrication of radiation shielding elements and radiation protection equipment.In this paper we discuss the investigation results of two tungsten containing water solutions: sodium tungstate dihydrate (Na₂WO₄ · 2H₂O) and silicotungstic acid (H₄SiW₁₂O₄₀ · xH₂O). Aqueous solutions containing different concentrations of tungsten products were fabricated and their X-ray attenuation properties were investigated. Since these solutions were thought for application as the fillers in aquarium type radiation protection screens their lead equivalent was calculated. Radiation protection screen of this type were developed for application in interventional radiology departments. It was found, that the lead equivalent of investigated solutions was dependent on concentration of tungsten compounds. Solutions containing ≥30% of sodium tungstate and ≥45% of silicotungstic acid indicated lead equivalent ≥0.25 mmPb, thus meeting the requirements set for radiation protection equipment.

Development of single-molecule force spectroscopy instruments as atomic force microscope (AFM), optical tweezers and magnetic tweezers, allows for manipulation of individual molecules and measurements of intermolecular forces with pico Newton resolution. In all these techniques the molecules are physically or chemically bound to larger bodies, which can be moved with high spatial precision. In typical force spectroscopy experiments performed by AFM, the AFM tip is pushed for some time to a substrate in order to pick up a molecule from the substrate surface. Binding of the molecule to the tip and substrate is probed by the occurrence of the characteristic entropic force-extension pattern of the molecule on the force-displacement curve observed during the tip retraction form the substrate.In the present work collagen type I molecules isolated from rat tail were deposited on silicon wafers. To enhance formation of hydrogen bonds between collagen molecules and either silicon AFM probes and substrates, the AFM probes and substrates were cleaned and hydroxylated in negative glow plasma of a dc discharge in low-pressure air. Then, the collagen molecules were deposited by imbedding the hydroxylated silicon wafers in aqueous solutions of collagen molecules for 2 h. AFM images of dried collagen samples showed a complete coverage of substrates with a thick layer of collagen molecules. A sample consisting in isolated collagen molecules deposited on freshly cleaved mica is used for comparison. Single molecule stretching experiments were made on large numbers of collagen molecules picked up from either hydroxylated silicon or mica substrates. The entropic force-extension curves obtained in experiments were fitted using the worm like chain model of chain molecules to determine the contour length, persistence length and binding force values. Dispersion of the values of these parameters obtained in a statistically significant number of measurements are discussed on base of statistical variation in molecule binding sites and contribution of molecule-substrate interaction forces to the measured single-molecule stretching force.

Due to the chemical and radiation resistance, strength, inertia and biocompatibility properties, synthetic polycrystalline thermoplastic polymer polyetheretherketone (PEEK) is used in implantology and dentistry. Successful application in medicine requires proper surface wetting properties. Implantology intended to provide a hydrophilic, better attachment of cells to the implant surface. Meanwhile, different dental prostheses are required to be hydrophobic. The changes of contact angle, surface energy, and morphology of the polyetheretherketone surface after treatment in nitrogen, oxygen and argon plasma were investigated in this work. The dentine and gingiva PEEK MED 98H14 samples were cleaned for 10 min. with ultrasound in alcohol surrounding before plasma treatment which influenced 18°–23° decreasing of surface contact angle. It was noted that dentine PEEK MED 98H14 was more sensible for the argon and oxygen plasma treatment when ion energy is higher (500 eV) and surface of those samples becomes more hydrophobic. Repeating of experiments at the same conditions with gingiva PEEK MED 98H14 showed the opposite results – contact angle of surface decreased and samples become more hydrophilic. Treatment of both materials with nitrogen plasma resulted the decrease of contact angle by 5°.

To investigate the effect of phase transitions of the fluid on thermal convection, we are conducting experiments of thermal convection of the mixture of a thermosensitive gel and water. The gel absorbs water and swells below a certain critical temperature, while it discharges water and contracts above the critical temperature. The swelling ratio, as well as the critical temperature, can be controlled, which enables us to investigate the effect of phase transition in a series of experiments, where the critical temperature is set between the top and bottom boundary temperatures and the swelling ratio is systematically changed. In flow visualization, we have observed temporally stable and spatially fixed low-velocity regions which are surrounded by distinct high-velocity regions. Such a phenomenon is not observed in thermal convection of a single-phase fluid like water or air, and peculiar to the phase-changing fluid. Also, we have measured the rheological properties of the fluid and found, for example, the shear-thinning behavior, with which we try to explain the observed convection behaviors.

In this paper, we introduce an antenna-based energy harvesting device for generating electricity from infrared radiation. The proposed device is based on nanoantennas, terahertz rectifying diodes and concentrator lenses. Diodes integrated together with antennas can transform the energy of electromagnetic radiation into electricity by rectifying the high frequency currents induced in the antennas. We consider an array of diode coupled nanoantennas over a suitable substrate. A layer of micro lenses is placed on top of the antenna array to focus the incident light. This can considerably boost the conversion efficiency of the antenna array. A theoretical description of the proposed device is presented. Based on the existing experimental results, conversion efficiency of ~77% is estimated for the 10 µm infrared radiation.

The goal of the present work is to study the regulations of the changes of the characteristics of high frequency optical signals using both quantitative and qualitative terms, on the basis of changes statistical parameters of turbulent media on the random phase screen model. There is an analytical assessment of statistical moments of laser radiation via random phase screen by numerical modeling and comparison with known experimental results. The object of the study is a random inhomogeneous atmosphere with weak turbulence, as well as optically dense turbulent media. The model of a random phase screen is discussed and the distribution of the statistical moments of scattered laser radiation is studied. The dependence of the effective size of the laser beam and the scintillation index on the correlation radius of the phase screen in the plane of the detector for a random phase screen is estimated.

In disaster situations, it is necessary to rapidly determine the locations of traffic jams and abandoned vehicles to find traffic routes so that rescue activities can be carried out efficiently. However, it takes time to recognize vehicles and estimate their positions. The purpose of our study is to rapidly detect vehicles and their positions in the case of disasters. We propose a method of vehicle recognition and position estimation using an aerial image taken from a helicopter and a road map. Although such images can be taken locally, occlusion occurs when buildings are reflected on the road. For vehicle recognition, we use shadow correction, asphalt removal by machine learning, and shape analysis. In addition, we remove buildings to solve the problem of occlusion. First, we adjust the color of the aerial image by shadow correction. Then, we remove areas of asphalt and buildings on the road, and we extract vehicle areas by using their shape features. To estimate the positions of vehicles, we project the road map on the aerial image by a projective transformation. We extract the road area from the aerial image by the projection before vehicle recognition, thus increasing the efficiency of the process. Using our method, we successfully detected most vehicles with owing to their different colors from the asphalt. Furthermore, we marked the positions of the vehicles on the road map. We thus demonstrated the possibility of the rapid detection of vehicles from aerial images in disaster situations.

Digital images undergo irreversible compression to enable transmission, a process which induces visible and often annoying distortions. Post-compression enhancement algorithms attempt reduce the visual impacts of these distortions. One such enhancement technique, designed specifically for textures, employs perceptually shaped noise patterns. Although this technique is quite effective, the contrasts of the patterns must be properly scaled, thus necessitating an algorithm that can automatically predict these scaling factors. To help enable such a prediction, we investigated whether patterns which have higher contrast detection thresholds (CTs) [i.e., patterns which require more contrast to be just-visible] also require higher contrast scaling factors (CSs) for proper enhancement. We measured CTs in the current study and compared them with CSs measured in our previous study. Our results support the hypothesis that low CT implies low CS, and vice-versa, but only for those patterns which could markedly improve the visual quality.

Minimally invasive robots are currently used during the operations of human body in the entire world. There are various important mechanical quantities in the designing process of a medical robot structure, such as the dynamic safety factor, which is reckoned in this following article. Matlab program was used to calculate the torque in every joint with a DC motor, controlled with PID regulator for a given trajectory. Trajectory allows the effector to move in the tunnel of a tissue inside the patient’s chest (tunnel was obtained by using 3D Slicer computer program and CT scan diagnostics). Subsequently, the FEM (finite element method) was applied to enumerate transient conditions during the deformation of robots’ structure (RRRS). Numerical experiment of multi-objective optimization is introduced in the work, where two criteria, during the calculation, are very significant: first natural frequency and dynamic safety factor for multibody effector of a medical robot in motion, taking into account the inertia, damping, and stiffness reactions. The Pareto optimum for these criteria is calculated by using a genetic algorithm. The mini robot effector is finished with a scalpel.

It is useful to obtain road traffic information quickly for disaster rescue and remediation activities. Utilizing aerial images for determining road traffic conditions is an effective means that is not affected by the situation on the ground. In particular, helicopters can be used to not only grasp road traffic conditions but also aid rescue activities. Moreover, systems that transmit real-time images to ground stations, such as helicopter relay systems and helicopter satellite systems, have attracted attention. In fact, such systems widely contributed to the rescue activities after the Kumamoto earthquakes that occurred in April 2016. However, there is a large difference between the fixation point and position of photographing because aerial images are obtained obliquely with respect to the ground surface, which remains a problem. In this study, we identify the fixation point without utilizing any large special equipment by only using information from the global positioning system (GPS) and a map. Ultimately, we aim to use the results of registration between the images and maps to grasp road traffic conditions.

This work presents a project of new interference image analysis software. The main idea was to create a new algorithm that uses the position of functions local maxima to detect the wedges position change. The purpose of this software is to determine the possibility of using flat-parallel plate interference to determine the position of the wedge plate in relation to the laser beam, with the use of CCD camera.

The article presents an innovative method of kidney recognition in computed tomography (CT) images. Kidney cancer is one of the most common causes of death. Over 300,000 people die per year from this disease. A fast and correct diagnosis of neoplastic lesions in computed tomography images allows to choose the proper method of treatment. This article presents innovative and unique methods of kidney recognition in CT images. The proposed methods are based on morphological operations, shape analysis, geometrical coefficients calculations as well as the directional operation of flood fill with automatic selection of the stop criterion. The article presents also an innovative method of closing the boundary of an unrecognized kidney. Application of fast and effective algorithms for an automatic kidney shape recognition allows to make a 3D reconstruction of the kidney model. The use of algorithms to improve visualization of CT scans allows more accurate diagnosis by specialists. The system for supporting kidney cancer diagnosis presented in the article has been tested to assess the quality of kidney shape recognition. The recognition results of the shape of the kidney by the automatic system are comparable to the results obtained by a human expert and the accuracy of the diagnosis is at the level of 86%. Despite the difficult task, it was possible to obtain satisfactory results of the kidney shape recognition.

In this study, a hybrid algorithm of adaptive neuro fuzzy inference system (ANFIS), particle swarm optimization (PSO) and principle component analysis (PCA) is utilized to predict the reference evapotranspiration (ET0). The accuracy of the computational model is evaluated using four statistical tests including Pearson correlation coefficient (r), mean square error (MSE), root mean-square error (RMSE), and coefficient of determination (R2). The results show that the ET0 can be estimated with an acceptable accuracy trough combination of PCA and ANFIS. Moreover, the result indicated that the ANFIS model can be simplified via reducing dimensionality of the input data.

Marangoni convection is a flow along the interface between two fluids due to the variation of surface tension, which is mainly caused by temperature and/or concentration gradients, namely thermal and/or solutal Marangoni convection(s). During the crystal growth by the floating zone method, Marangoni convection may induce the striation and affect the quality of growing crystal. Therefore, it is necessary to understand the convective phenomenon and control it. In this study, a three-dimensional configuration of the half-zone liquid bridge in the crystal growth of Si_xGe_1-x was selected by establishing the temperature and concentration differences. The equations of continuity, momentum, energy and mass transfer were solved by the PISO algorithm in the OpenFOAM. Thermal and solutal Marangoni convections were set to flow in the opposite direction under zero gravity in the melt with different Marangoni numbers. Results have shown that when Ma_C is larger than −Ma_T, the flow is steady and axisymmetric, while Ma_C is smaller than −Ma_T, the flow is unsteady and irregular. As for the control of Marangoni convection, rotation of top and bottom plane in the liquid bridge was applied during the crystal growth. With different rotation speeds and directions, the suppression of Marangoni convection can be effectively realized by the appropriate forced rotation.

A single level linked list (a simple list) is a dynamic data structure that is used for storing data in applications. However, there are also multi-level linked lists (called skip lists) that are more complicated for creating, but searching for the required data elements in them is more efficient because they allow us to skip to the correct element in them. We have created a C# object-oriented .NET application that uses both lists, a skip and simple list, with structured data in their data elements. By using our C# application we want to compare the execution efficiency of the use of these lists, therefore the same structured data of students is stored in the data elements of its skip and simple list. Our C# application is able to carry out basic operations with these data elements of a skip and simple list, such as searching for students (data elements) according to their points for accommodation, their year of birth, their surname and according to their ISIC in both lists, inserting of a new student (a data element) sorted into both lists etc., and simultaneously it is able to measure the execution times of particular operations. By comparing these times we have examined the execution efficiency of these operations in a skip list and in a simple list. The results and evaluation of this examination are listed in the paper.

This is a case study of one student’s research about the Nash equilibrium in the context of board games. First set the stage, i.e. describe the educational environment. In 1995 Faculty of Informatics was a new faculty. The faculty itself was a “simulation,” establishing a viable institution of higher learning. An irregular procedure made it possible for a Bachelor’s degree 4th year (B4) in computer science (CS) student to choose the General Systems Theory (GST) Lab’s (LAB) Event Planning and Game Theory (GT) lab for graduation research. The lab has keywords GST, experiential learning, GT, requisite variety, etc. Educational environment impacts strategic learning (Young 2004), at the level of student, faculty, staff, and university. The third player in this account is a Master of Science (MS) candidate who was LAB’s Teaching Assistant (TA).3 players/stakeholders hold different roles in this account: LAB’s job is to provide praxis of requisite variety and a layered educational environment for Science, Technology, Engineering, and Mathematics (STEM) students. This story is a learning story with a template. B4 required an environment for experiments with main interest in the board game shogi. How B4 linked the “sacrifice move” to Nash equilibrium is the goal of this narrative. TA provided crucial insight at the right time.

In this paper, we present a Cluster-Based Approach (CBA) that utilizes the support vector machine (SVM) and an artificial neural network (ANN) to estimate and predict the daily horizontal global solar radiation. In the proposed CBA-ANN-SVM approach, we first conduct clustering analysis and divided the global solar radiation data into clusters, according to the calendar months. Our approach aims at maximizing the homogeneity of data within the clusters, and the heterogeneity between the clusters. The proposed CBA-ANN-SVM approach is validated and the precision is compared with ANN and SVM techniques. The mean absolute percentage error (MAPE) for the proposed approach was reported lower than those of ANN and SVM.

Nowadays, parallelization is an increasingly popular tool to speed up algorithms. Data classification is one of the many fields of computer science that can take significant advantage of that. In this paper, a parallel implementation of Fuzzy RBF based filters are proposed for pattern recognition problems. It realizes a simple pattern matching by using the radial basis functions for proximity detection, then simply choosing the class or label associated to the pattern as output. The classifier has the advantage of being very simple to implement, to train and to modify the obtained knowledge. With the parallel computing improvement, the speed of both the training and evaluation phase are significantly increased compared to the sequential implementation.

Research on induced Pluripotent Stem (iPS) cell has attracted attention due to their remarkable progress in regenerative medicine. Cost and quality are two main factors to be considered when using iPS cells in biological applications in a large scale. In this study, the suspension culture of iPS cells was numerically simulated in a cylindrical tank under the two-different shaking methods; one-direction rotation and periodic alternate rotation. The two shaking methods exhibited a significant difference in the average number of cells accumulated in the bottom. Even though the one direction rotation method suppressed the shear stress acting on iPS cells, after eight seconds it accumulated more cells in the bottom than the periodic alternate rotation method.

While we reported positive changes in class atmosphere in “Flipping Out in Japan” at iA2017 in Iasi, Romania, questions regarding empirical evidence of language improvement were lacking. Also, the control and experimental groups were not adequately demarcated. Our evaluations were subjective and impressionistic. With the addition of a third partner who advised a final testing protocol, we hope to address both of these criticisms with replicable test results. In this article, we re-examine our premises and the goals of our research. The “flipped classroom,” or experiential learning, is all about context, and because both control and experimental groups did well last year in the class with a decidedly improved atmosphere, we decided this year to maintain the “flipped” format for both groups. With the enhancements of a senior student “mentor” and visitors to the experimental group, and two native English speakers teaching the control group, we are relying on a series of quizzes structured on the relevant material in each module of the class, with the final exam based on those quizzes, to provide robust empirical data which will convince peers of the approach’s utility.