Pouzdanost primene konvencionalnih ključeva za određivanje boje zuba

Background/Aim. Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest ΔE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. Methods. VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: ΔL, ΔC, ΔH, ΔE, ΔElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. Results. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Conclusion. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.Uvod/Cilj. Određivanje boje zuba u protetskoj terapiji predstavlja veoma važan zadatak jer utiče na prirodan izgled i estetsku vrednost zubnih nadoknada. Vizuelni metod određivanja boje zuba najčešće se koristi u kliničkoj praksi. Instrumentalna merenja pružaju objektivne i kvantifikovane podatke u proceni boje prirodnih zuba i restauracija. U instrumentalnoj analizi boje cilj je da se postigne najmanja moguća vrednost ΔE, što predstavlja najtačniji izbor nijanse. Cilj ovog istraživanja bio je da se utvrdi pouzdanost najčešće korišćenih ključeva za određivanje boje zuba. Metode. Za instrumentalni izbor boje korišćen je VITA Easyshade spektrofotometar (VITA, Germany). Uz pomoć ovog uređaja, analizirani su uzorci boja 10 VITA Classical i 10 VITA 3D - Master ključeva boja. Svaki uzorak boje analiziran je tri puta i ispitivani su osnovni parametri kvaliteta boje: ΔL, ΔC, ΔH, ΔE, ΔElc. Stepen poklapanje boje nadoknade sa ciljnom nijansom spektrofotometar izražava kroz tri ocene kvaliteta: good, fair i adjust. Rezultati. Nakon izvršenih 1 248 merenja keramičkih uzoraka boje, frekvencije ocena adjust, fair i good statistički su se značajno razlikovale između VITA Classical i VITA 3D - Master ključeva boja (p = 0.002). U VITA Classical ključu boja bilo je 27,1% ocene adjust, 66,3% fair i 6,7% ocene good. U VITA 3D - Master ključu boja bilo je 30,9% ocene adjust, 66,4% fair i 2,7% ocene good. Zaključak. Uzorci boje iz različitih ključeva boja proizvedenih od istog proizvođača, pokazuju varijabilnost u osnovnim parametrima boje, što ukazuje na nepreciznost i neuniformnost konvencionalne metode

Instrumentalno određivanje boje zuba u protetskoj rekonstrukciji

Tooth color selection in prosthodontics is a very important factor for successful rehabilitation. The aim of this paper was to present different instruments for tooth color selection in prosthodontic rehabilitation. Knowledge of basic principles of a complex psychophysical phenomenon such as color is of essential interest in prosthodontic therapy. Furthemore, the mechanism of physiological perception of color and available methods for an objective determination of tooth color are also presented in the paper.Određivanje boje zuba u stomatološkoj protetici predstavlja važan faktor uspeha protetske rehabilitacije. Ciljovog rada je bio da jasno predstavi različite instrumente za određivanje boje u protetskoj rehabilitaciji. Poznavanje elementarnih postulata o složenom psihofizičkom fenomenu kao što je boja, za terapeuta je od esencijalnog interesa u protetskoj terapiji. Takođe su predstavljeni procesi fiziološke percepcije boje i apostrofirane metode koje su dostupne stručnoj praksi za objektivno vrednovanje boje zuba

Long cycle life of CoMn2O4 lithium ion battery anodes with high crystallinity

CoMn2O4 nanomaterials are prepared by a low temperature precipitation route employing metal acetates and NaOH. Structural changes, induced by different annealing temperatures, are comprehensively analyzed by X-ray powder diffraction and Raman spectroscopy. With rising annealing temperature the crystal lattice of CoMn2O4 undergoes changes ; AO4 tetrahedra expand due to thermally induced substitution of Co2+ by larger Mn2+ metal ions on the A-site of the spinel structure, while in contrast, BO6 octahedra shrink since the B-site becomes partially occupied by smaller Co3+ metal ions on account of the migrated Mn ions. CoMn2O4 particle sizes are easily fine-tuned by applying different annealing temperatures ; the particle size increases with increasing annealing temperature. During the battery operation, pulverization and reduction of particle sizes occurs regardless of the initial size of the particles, but the degree of division of the particles during the operation is dependent on the initial particle properties. Thus, contrary to the common assumption that nanostructuring of the anode material improves the battery performance, samples with the largest particle sizes exhibit excellent performance with a capacity retention of 104% after 1000 cycles (compared to the 2nd cycle)

Hibridni solarno-električni sistemi za unapređenje energetske efikasnosti u pripremi i korišćenju sanitarne tople vode u domaćinstvima

Hot water consumption in households is an essential component in the energy consumption structure and represents a significant potential for improving the energy efficiency of this category of consumers. In this paper a hybrid solar-electric system for obtaining hot water is proposed. The basic idea is the primary use of roof-integrated solar thermal systems for the preparation of hot water used by domestic sanitary appliances. Classic electrical heaters in sanitary facilities would be a secondary system that would ensure reliability of the system in conditions of insufficient insolation.This paper presents basic elements of improvement of existing installations of sanitary devices and energy balance calculations and savings that are made in relation to standard solutions. In addition to significantly improving energy efficiency, very significant effects have been achieved in terms of increasing the speed of work processes performed by individual domestic appliances, such as washing machines and dishwashers. Hybrid solarelectric systems for improving energy efficiency in the preparation and use of domestic hot water in householdsu strukturi potrošnje energije i predstavlja značajan potencijal za unapređenje energetske efikasnosti ove kategorije potrošača. U ovom radu je predložen hibridni solarnoelektrični sistem za dobijanje tople vode. Osnovna ideja je primarno korišćenje krovno integrisanih solarno-termalnih sistema za pripremu tople vode koju koriste sanitarni uređaji u domaćinstvu. Klasični električni grejači u sanitarnim uređajima bi bili sekundarni sistem koji bi obezbeđivao pouzdanost rada sistema u uslovima nedovoljne insolacije. U ovom radu prikazani su osnovni elementi unapređenja postojećih instalacija sanitarnih uređaja i izvršeni proračuni energetskog bilansa i ušteda koje se ostvaruju u odnosu na standardna rešenja. Pored značajnog unapređenja energetske efiksanosti postignuti su i veoma značajni efekti u pogledu povećanja brzine radnih procesa koje obavljaju pojedini sanitarni uređaji u domaćinstvu, kao što su veš mašine i mašine za pranje suđa

Hibridni solarno-električni sistemi za unapređenje energetske efikasnosti u pripremi i korišćenju sanitarne tople vode u domaćinstvima

Hot water consumption in households is an essential component in the energy consumption structure and represents a significant potential for improving the energy efficiency of this category of consumers. In this paper a hybrid solar-electric system for obtaining hot water is proposed. The basic idea is the primary use of roof-integrated solar thermal systems for the preparation of hot water used by domestic sanitary appliances. Classic electrical heaters in sanitary facilities would be a secondary system that would ensure reliability of the system in conditions of insufficient insolation.This paper presents basic elements of improvement of existing installations of sanitary devices and energy balance calculations and savings that are made in relation to standard solutions. In addition to significantly improving energy efficiency, very significant effects have been achieved in terms of increasing the speed of work processes performed by individual domestic appliances, such as washing machines and dishwashers. Hybrid solarelectric systems for improving energy efficiency in the preparation and use of domestic hot water in householdsu strukturi potrošnje energije i predstavlja značajan potencijal za unapređenje energetske efikasnosti ove kategorije potrošača. U ovom radu je predložen hibridni solarnoelektrični sistem za dobijanje tople vode. Osnovna ideja je primarno korišćenje krovno integrisanih solarno-termalnih sistema za pripremu tople vode koju koriste sanitarni uređaji u domaćinstvu. Klasični električni grejači u sanitarnim uređajima bi bili sekundarni sistem koji bi obezbeđivao pouzdanost rada sistema u uslovima nedovoljne insolacije. U ovom radu prikazani su osnovni elementi unapređenja postojećih instalacija sanitarnih uređaja i izvršeni proračuni energetskog bilansa i ušteda koje se ostvaruju u odnosu na standardna rešenja. Pored značajnog unapređenja energetske efiksanosti postignuti su i veoma značajni efekti u pogledu povećanja brzine radnih procesa koje obavljaju pojedini sanitarni uređaji u domaćinstvu, kao što su veš mašine i mašine za pranje suđa

Reliability of conventional shade guides in teeth color determination

Background/Aim. Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest ΔE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. Methods. VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: ΔL, ΔC, ΔH, ΔE, ΔElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. Results. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Conclusion. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method

Reliability of conventional shade guides in teeth color determination

Background/Aim. Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest ΔE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. Methods. VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: ΔL, ΔC, ΔH, ΔE, ΔElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. Results. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Conclusion. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.Uvod/Cilj. Određivanje boje zuba u protetskoj terapiji predstavlja veoma važan zadatak jer utiče na prirodan izgled i estetsku vrednost zubnih nadoknada. Vizuelni metod određivanja boje zuba najčešće se koristi u kliničkoj praksi. Instrumentalna merenja pružaju objektivne i kvantifikovane podatke u proceni boje prirodnih zuba i restauracija. U instrumentalnoj analizi boje cilj je da se postigne najmanja moguća vrednost ΔE, što predstavlja najtačniji izbor nijanse. Cilj ovog istraživanja bio je da se utvrdi pouzdanost najčešće korišćenih ključeva za određivanje boje zuba. Metode. Za instrumentalni izbor boje korišćen je VITA Easyshade spektrofotometar (VITA, Germany). Uz pomoć ovog uređaja, analizirani su uzorci boja 10 VITA Classical i 10 VITA 3D - Master ključeva boja. Svaki uzorak boje analiziran je tri puta i ispitivani su osnovni parametri kvaliteta boje: ΔL, ΔC, ΔH, ΔE, ΔElc. Stepen poklapanje boje nadoknade sa ciljnom nijansom spektrofotometar izražava kroz tri ocene kvaliteta: good, fair i adjust. Rezultati. Nakon izvršenih 1 248 merenja keramičkih uzoraka boje, frekvencije ocena adjust, fair i good statistički su se značajno razlikovale između VITA Classical i VITA 3D - Master ključeva boja (p = 0.002). U VITA Classical ključu boja bilo je 27,1% ocene adjust, 66,3% fair i 6,7% ocene good. U VITA 3D - Master ključu boja bilo je 30,9% ocene adjust, 66,4% fair i 2,7% ocene good. Zaključak. Uzorci boje iz različitih ključeva boja proizvedenih od istog proizvođača, pokazuju varijabilnost u osnovnim parametrima boje, što ukazuje na nepreciznost i neuniformnost konvencionalne metode

Зграде школских и предшколских установа - методолошки оквир формирања типологије и побољшања енергетске ефикасности

Монографија ”Зграде школских и предшколских установа – методолошки оквир формирања типологије и побољшања енергетске ефикасности” представља теоретску подлогу рада и основне принципе истраживања којим су посебно обухваћени: историјски преглед развоја зграда школских и предшколских установа, развој регулативе ове области, методологија вршења пописа и формирања типологије зграда, принципи унапређења и прорачун потенцијалне уштеде енергије као и смањења емисије угљен-диоксида кроз процесе енергетске обнове зграда на нивоу Републике Србије.Monograph “School and Kindergarten Buildings- a methodological framework for the formation of typology and the improvement of energy efficiency” represents a theoretical basis of our work and basic research principles, especially covering the following: historical overview of the school and kindergarten buildings development, development of legislation in this area, methodology for taking inventory and forming the typology of buildings, improvement principles and calculation of potential energy savings and CO2 emission reduction via the processes of energy rehabilitation of buildings in the Republic of Serbia

National typology of school buildings in Serbia

Book 2 Typology of School Buildings presents the defi ned matrix following the insight into the principles and limitations of its formation, and provides the calculations for energy performance for selected typological representatives. The calculations were carried out in accordance with the current regulations, and were followed by recommendations for improving the energy effi ciency of buildings. In comparison with the National Typology of Residential Buildings, there are three proposed scenarios for improvement by the application of the appropriate package of measures. Taking into account the applicability of the methodology, the proposed technical and technological solutions were adjusted to the characteristics of buildings and the market potential, i.e. economic parameters. The potential for reducing the required heating energy and CO2 emissions was calculated for all levels of improvement, both for the individual building types and for the entire segment of the building stock in the Republic of Serbia.Knjiga 2 Tipologija školskih zgrada koja je posvećena školskim zgradama, daje principe i ograničenja pri formiranju tipološke matrice škola, definisanu matricu, kao i proračune energetskih karakteristika za odabrane tipološke reprezente. Proračuni energetskih performansi su izvršeni u skladu sa važećom regulativom, uz definisanje preporuka za poboljšanje energetske efikasnosti zgrada. U ovom slučaju su, za razliku od Nacionalne tipologije stambenih zgrada, unapređenja predviđena korz tri moguća nivoa primenom odgovarajućih paketa mera. Imajući u vidu primenljivost metodologije, uzeta su u obzir tehničko-tehnološka rešenja prilagođena karakteristikama zgrada i mogućnostima tržišta, to jest ekonomskim parametrima. Za sve nivoe unapređenja izračunat je potencijal redukcije potrebne energije za grejanje, to jest smanjenja emisije ugljen-dioksida, kako za pojedinačne tipove, tako i za celokupan segment građevinskog fonda na nivou Republike Srbije