Laguerre-like methods for the simultaneous approximation of polynomial multiple zeros

Two new methods of the fourth order for the simultaneous determination of multiple zeros of a polynomial are proposed. The presented methods are based on the fixed point relation of Laguerre's type and realized in ordinary complex arithmetic as well as circular complex interval arithmetic. The derived iterative formulas are suitable for the construction of modified methods with improved convergence rate with negligible additional operations. Very fast convergence of the considered methods is illustrated by two numerical examples

A new higher-order family of inclusion zero-finding methods

AbstractStarting from a suitable fixed point relation, a new one-parameter family of iterative methods for the simultaneous inclusion of complex zeros in circular complex arithmetic is constructed. It is proved that the order of convergence of this family is four. The convergence analysis is performed under computationally verifiable initial conditions. An approach for the construction of accelerated methods with negligible number of additional operations is discussed. To demonstrate convergence properties of the proposed family of methods, two numerical examples results are given

Izbor biomaterijala - višekriterijumska analiza i razvoj sistema za podršku odlučivanju

Community development has led to the increasing use of biomaterials, which are used for making prostheses and implants. The topic of this doctoral dissertation is selection of biomaterials by using multi-criteria decision making methods. First of all the material selection problem, its actuality and methods that used to solve the problem are described. Then the basic principles of multi-criteria decision making theory with specifics of its application for material selecetion are explained. Existing multi-criteria decision making methods are adapted so that they can be successfully and reliably used for the selection of biomaterials. The procedures of three methods used in this dissertation (Extended TOPSIS, Extended WASPAS and Comprehensive VIKOR) as well as methodology for determination of criteria weightings are described in detail. Furthermore it is outlined methods for comparison of solutions obtained by different methods. In the following chapter, basic definitions, terms and requirements regarding biomaterials are listed, which is followed by a detailed review of metallic biomaterials. Three case studies of biomaterials selection by means multi-criteria decision making methods are considered. The first one is selection of biomaterial for bone fixation plates, the second one is biomaterial selection for femoral part of hip prosthesis and the third one is selection of biomaterial for femoral component of knee prosthesis. Finally, it is developed a decision support system (MCDM Solver). in which adapted multi-criteria decision making methods are incorporated. Checking and validation of the developed decision support system is carried out through the use of the previously solved case studies

Еталонирање терестричких ласерских скенера у лабораторијским условима

Терестричко ласерско скенирање (ТЛС) представља методу брзог прикупљања велике количине података у виду „облака тачака“ који нам касније представља основу за приказивање реалног стања „објекта“ у виду тродимензионалног модела и вршење разних анализа над њим. Перманентни развој технологије, хардвера и софтвера у претходних 10-ак година је у великој мери утицао на експанизију методе ТЛС-а, и на квалитет података који добијамо као резултат њене примене. Методу ТЛС-а можемо декларисати као једну од „најмлађих“ метода која се користи у геодезији, грађевинарству, архитектури, просторном планнирању и др. Међутим, методи ТЛС-а недостају јасно дефинисане и стандардизоване теренске процедуре као и методе испитивања и еталонирања инструмената и прибора који се користи. Такође, још увек не постоји међународни стандард који би унифицирао декларисање карактеристика инструмената од стране произвођача. У овом раду је дат преглед свих процеса и прорачуна у циљу успостављања метролошког полигона за потребе еталонирања терестричко ласерских скенера. Приказана је и анализа података прикупљених приликом еталонирања три модела терестричко ласерских скенера

The effect of architectural façade design on energy savings in the student dormitory

There are many reasons for adequate use of natural light inside students' dormitories. Intensity of light required for student activities and temperature inside the rooms are the major factors for an occupant's comfortable work and life. Design of building façades has a significant impact both on the use of natural light and energy consumption. In this paper, a comparative analysis of student rooms with different orientations and different façade designs was performed in order to investigate what type of refurbishment in the façade is necessary. The goal of the refurbishment was generation of optimal thermal and lighting comfort for students' work with maximal energy saving for a new student dormitory in Nis, Serbia. An analysis of annual energy consumption of the newly designed student dormitory and proposed replacements on the exterior façade was performed by using the software EnergyPlus. Based on the energy consumption analysis it could be concluded that significant energy savings would be possible by upgrading the shading devices across the width of the window. In other words, changing the façade of the dorm could generally improve students' comfort, while the energy costs would be reduced. [Projekat Ministarstva nauke Republike Srbije, br. TR 36037: Development of student dorms in Serbia at the beginning of the 21st century i br. TR 33051: The concept of sustainable energy supply of settlements with energy efficient buildings

Microwave Assisted Esterification of Aryl/Alkyl Acids Catalyzed by N-Fluorobenzenesulfonimide

The susceptibility of the carbonyl group towards nucleophilic attack affords the construction of various organic compounds. Thus, investigations of carbonyl activation applying greener methodologies are highly important. In the present work, among the investigated N-halo compounds, N-fluorobenzenesulfonimide (NFSi) has been found as an efficient and selective catalyst in the reaction of direct esterification of aryl and alkyl carboxylic acids supported by microwave (MW) irradiation. The comprehensive esterification of different benzoic acids and mono-, di-and tri-carboxy alkyl derivatives was performed, whereby significant reaction time reductions were achieved. The presented method used NFSi as an easily manipulatable, non-metal, water-and air-tolerant catalyst, allowing simple synthetic and isolation procedures and energy saving, compared to conventional methodologies. Importantly, in contrast to esterification under thermal conditions, where N-halo compounds behave as pre-catalysts, in the MW-supported protocol, a distinct reaction mechanism has been proposed that assumes NFSi as a sustainable catalyst. Moreover, a scale-up of the industrially important derivative was performed

Influence of the periodic changes in the incoming solar hydrogen Ly-α radiation intensity on the total electron content in the ionospheric D-region

This paper analyzes variations in the total electron content in the D-region induced by periodical changes in the solar hydrogen Lyα radiation. The considered changes are a consequence of variations in the solar radiation intensity during a solar cycle and a consequence of the Earth's revolution. The presented analysis is based on the Quiet ionospheric D-region (QIonDR) model, which shows the dependencies of ionospheric parameters on the smoothed daily sunspot number and season. We consider the vertical and slant (for different zenith angles) total electron content in the D-region (TECD) which are important for calculations of delays of satellite signals. The obtained results show a significant influence of the considered zenith angle and period of the solar cycle and season on calculating the considered ionospheric parameter.IV Meeting on Astrophysical Spectroscopy - A&M DATA - Atmospher

BIOCHEMICAL AND HISTOPATHOLOGICAL EFFECTS OF MOBILE PHONE EXPOSURE ON RAT HEPATOCYTES AND BRAIN

Microwave radiation MWR is widespread in human environment. The most frequent sources of MWR are mobile phones and cell towers. The effects of MWR are still unknown and there are insufficient data about long-term MWR effects on hepatocytes and brain structures.The aim of this paper was to investigate the biological effects of mobile phone microwave radiation on the brain and liver of experimental animals and to determine the increase in oxidative stress as a possible pathogenetic mechanism for harmful effects of long-term exposure.Wistar rats, 3 months old, were divided into two groups: I-rats constantly exposed to MWR (3 female and 2 male) and II-control animals without near source of electromagnetic field (EMF) (3 female and 2 male). The microwave radiation was produced by a mobile test phone (model NOKIA 3110; Nokia Mobile Phones Ltd.) connected to a Communication Test Set (model 4202S; Wavetek, Germany). A 900 MHz electromagnetic near-field signal for GSM (Global System for Mobile communication at 900 MHz, continuous wave, analog phone) system was used. The whole-body specific energy absorption (SAR) rate was estimated as 0.025-0.05 W/kg (E=9.8-18.3 V/m, B=4.8-8.6 µT). Rats were sacrificed after 3 months of MWR exposure. The liver and brain were fixed in 10% formaldehyde and paraffin sections were stained by HE. The biochemical analyses comprised the determination of serum activity of AST (Aspartate aminotransferase), ALT (Alanine transaminase), GGT (Gamma-glutamyl transpeptidase) and LDH (Lactate dehydrogenase), as well as determination of serum concentration of sodium, potassium and chloride. Lipid peroxidation was determined by measuring the quantity of malondialdehyde (MDA).Slightly increased number of micronuclei and discrete perivenular fatty changes were only histopathological findings in the liver of exposed rats. The discrete reduction of gray matter and reduced size and number of dendritic spines of Purkinje cells in cerebellum were notified as well. The serum activity of ALT was significantly increased (p<0.05), while activities of AST, GGT and LDH did not changed in the exposed rats. Potassium serum concentration was significantly higher in the exposed rats, while the concentration of sodium and chloride did not differ. The MDA concentration was significantly higher in the brain and liver tissues of MWR-exposed rats.The results in this study show significant increase in lipid peroxidation as a direct indicator of the hepatocytes and brain cells’ injury under a long-term (90 days) mobile phone microwave exposure. The hyperkalemia could be the possible systemic marker of impaired cells membrane fluidy and increased permeability, alongside with increased ALT activity as marker of hepatocelular damage. Disorders of hypothalamo- hypophyseal axis lead to disturbances in affective behaviour, but also to disturbances of neurovegetative functions, which leads to behavioral changes and increased appetite and weight gain in exposed animals

The visualization of the medieval site of the Savinac monastery

Contemporary visualization techniques rely on new technological achievements which offer information data collection in the form of a three-dimensional model. Such 3D model is significant in the area of cultural heritage protection and specifically in the restoration processes of ruined monuments. The results of applications of both methods, terrestrial laser scanning (TLS) and photogrammetry, is 3D data in the form of point cloud, which is a base for 3D modelling process in adequate software, and accordingly, a creation of an objects’ 3D shape. In this paper, the results of data collecting at the medieval site of the Savinac monastery (twelfth century ), performed in 2018, by using both contemporary methods, is presented. The visualization of this particular site is of the major importance for cultural heritge of Serbia

Synthesis, characterization and biological study of new dinuclear zinc(ii) and nickel(ii) octaaza macrocyclic complexes

Two new nitrato complexes of zinc and nickel with 1,4,8,11-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc), have been synthesized and characterized. The IR spectral peaks showed that the coordinated and ionic nitrate ions are in agreement with the formula proposed by elemental analysis. Conductometric titrations predicted methanol to be a convenient solvent for synthesis and revealed the stoichiometry of the complexes, while molar electrical conductivities indicated a 1 : 3 complex electrolyte type for the zinc complex, and a 1 : 2 complex electrolyte type for the nickel complex. The optimized complex structure was obtained by molecular modeling and density functional theory calculations. The biological activity of the novel complexes was examined by screening eight different bacterial strains and two cancer cell lines. The zinc complex showed better antimicrobial activity against the bacterial strains, while the complexes did not show significance antiproliferative activity toward cancer cells MCF-7 and MDA-MB-231