Orange-Reddish Light Emitting Phosphor GdVO 4 :Sm 3+ Prepared by Solution Combustion Synthesis

The gadolinium vanadate doped with samarium (GdVO 4 :Sm 3+ ) nanopowder was prepared by the solution combustion synthesis (SCS) method. After synthesis, in order to achieve the full crystallinity, the material was annealed in air atmosphere at 900°C. Phase identification in the postannealed powder samples was performed by X-ray diffraction, and morphology was investigated by high-resolution scanning electron microscopy (SEM). Photoluminescence characterization of the emission spectrum and time-resolved analysis have been performed using the tunable laser optical parametric oscillator excitation and the streak camera. Several strong emission bands in the Sm 3+ emission spectrum were observed, located at 567 nm ( 4 G 5/2 – 6 H 5/2 ), 604 nm ( 4 G 5/2 – 6 H 7/2 ), and 646 (654) nm ( 4 G 5/2 – 6 H 9/2 ), respectively. The weak emission bands at 533 nm ( 4 F 3/2 – 6 H 5/2 ) and 706 nm ( 4 G 5/2 – 6 H 11/2 ) and a weak broad luminescence emission band of VO 4 3− were also observed by the detection system. We analyzed the possibility of using the host luminescence for two-color temperature sensing. The proposed method is improved by introducing the temporal dependence in the line intensity ratio measurements

Time resolved study of temperature sensing using Gd 2 O 3 :Er,Yb: deep learning approach

This paper examines the potential applications of machine learning algorithms in the analysis of optical spectra from Gd2O3:Er,Yb thermophosphor. The material was synthesized using the solution combustion method. For data acquisition, we employed pulsed laser diode excitation at 980 nm and utilized a streak camera with a spectrograph to obtain time-resolved spectral data of the optical emission from Gd2O3:Er,Yb. To ensure data consistency and facilitate visualization, we employed principal component analysis and Uniform Manifold Approximation and Projection clustering. Our findings demonstrate that, instead of the conventional approach of identifying spectral peaks and calculating intensity ratios, it is feasible to train computer software to recognize time-resolved spectra associated with different temperatures of the thermophosphor. Through our analysis, we have successfully devised a technique for remote temperature estimation by leveraging deep learning artificial neural networks

Phytobiotics - natural growth stimulators in broiler feed

Фитогени додаци храни за животиње (фитобиотици) се дефинишу као једињења биљног порекла која се користе у исхрани животиња са циљем унапређења њихове продуктивности путем побољшања производних резултата животиња, својстава хране, као и квалитета намирница анималног порекла. Позитиван ефекат фитогених адитива (есенцијалних уља) у храни за животиње и њихових компоненти на производне резултате и здравље животиња је последица бројних својстава, од којих су најзначајнија њихова антиинфламаторна и антиоксидативна дејства, побољшање конзумације, стимулисање лучења ензима, повећање мотилитета желуца и црева, стимулација ендокриног и имуног система, антимикробно, антивирусно и кокцидиостатско деловање. Да би се испитао утицај исхране бројлера оброцима са додатим различитим фитогеним адитивима на здравствено стање, производне резултате, сензорне особине меса, као и оправданост кориштења фитогених адитива у исхрани бројлера организован је оглед на укупно 240 бројлера провенијенције Cobb 500, подељених у 4 групе. Храњени су стандардним смешама по препоруци произвођача, с тим што су се групе једино разликовале у томе што су огледне групе (О-I – О-IV) у смеши за исхрану имале додате различите комерцијалне фитогене адитиве а контролна група (К) без фитогеног адитива. Производни резултати (већи прирас, мања конзумација, боља конверзија) бројлера огледних група су били значајно бољи у односу на контролну групу бројлера у свим фазама това. У односу на бројлере посматраних огледних група код бројлера контролне групе утврђен је већи просечан број бактерија E. coli и Enteroccocus spp., а мањи број бактерија млечне киселине у испитиваним деловима дигестивног тракта. Посматране огледне групе су у свим испитиваним сегментима црева имале већу висину и ширину цревних ресица, а мању дубину крипти у односу на бројлере контролне групе, чиме је остварен већи ресорптивнии капацитет цревне слузнице. При сензорној анализи просечна оцена укупне прихватљивости меса груди О-I групе бројлера била је статистички значајно већа у односу на друге групе, а месо батака са карабатаком О-III групе бројлера у односу на О-I групу.Phytogenic feed additives (phytobiotics) are defined as compounds of plant origin used in animal nutrition with the aim of improving their productivity by improving the production results of animals, feed properties, as well as the quality of food of animal origin. The positive effect of phytogenic additives (essential oils) in animal feed and their components on production results and animal health is due to numerous properties, the most important of which are their anti-inflammatory and antioxidant effects, improving consumption, stimulating enzyme secretion, increasing gastric and intestinal motility, stimulation endocrine and immune systems, antimicrobial, antiviral and coccidiostatic action. In order to examine the impact of broiler diet with various phytogenic additives on health, production results, sensory properties of meat, as well as the justification of using phytogenic additives in broiler diet, a total of 240 broilers of Cobb 500 provenance were organized, divided into 4 groups. They were fed standard mixtures recommended by the manufacturer, with the only difference being that the experimental groups (O-I - O-IV) had different commercial phytogenic additives added to the feed mixture and the control group (K) without phytogenic additives. The production results (higher increment, lower consumption, better conversion) of broilers of the experimental groups were significantly better compared to the control group of broilers in all phases of fattening. Compared to the broilers of the observed experimental groups, the broilers of the control group had a higher average number of E.coli and Enteroccocus spp., and a lower number of lactic acid bacteria in the examined parts of the digestive tract. The observed experimental groups had a higher height and width of intestinal villi in all examined segments of the intestine, and a smaller depth of crypts in relation to the broilers of the control group, which achieved a higher resorptive capacity of the intestinal mucosa. In the sensory analysis, the average assessment of the total acceptability of breast meat O-I group was statistically significantly higher compared to other groups, and drumstick with thigh of O-III broiler group compared to O-I group.Zbornik radova i kratkih sadržaj

Biomechanical model produced from light-activated dental composite resins: a holographic analysis

Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.3rd International Conference on the Physics of Optical Materials and Devices, Sep 02-06, 2012, Belgrade, Serbi

Application of tot’hema eosin sensitized gelatin film for adaptive microlenses

In this paper we showed that tot’hema eosin sensitized gelatin (TESG) film can be used for adaptive microlenses fabriacation. The mechanical properties of a pure gelatin film were improved by adding tot’hema solution. We found that the elasticity of TESG film depend on the tot’hema concentration. By stretching the film, the microlenses were deformed uniaxially, and microlenses focal length can be tuned. The achieved microlenses focal lengths range from 0.05 to 0.2 mm

Three dimensional mathematical model of tooth for finite element analysis

Introduction. The mathematical model of the abutment tooth is the starting point of the finite element analysis of stress and deformation of dental structures. The simplest and easiest way is to form a model according to the literature data of dimensions and morphological characteristics of teeth. Our method is based on forming 3D models using standard geometrical forms (objects) in programmes for solid modeling. Objective. Forming the mathematical model of abutment of the second upper premolar for finite element analysis of stress and deformation of dental structures. Methods. The abutment tooth has a form of a complex geometric object. It is suitable for modeling in programs for solid modeling SolidWorks. After analyzing the literature data about the morphological characteristics of teeth, we started the modeling dividing the tooth (complex geometric body) into simple geometric bodies (cylinder, cone, pyramid,...). Connecting simple geometric bodies together or substricting bodies from the basic body, we formed complex geometric body, tooth. The model is then transferred into Abaqus, a computational programme for finite element analysis. Transferring the data was done by standard file format for transferring 3D models ACIS SAT. Results. Using the programme for solid modeling SolidWorks, we developed three models of abutment of the second maxillary premolar: the model of the intact abutment, the model of the endodontically treated tooth with two remaining cavity walls and the model of the endodontically treated tooth with two remaining walls and inserted post. Conclusion Mathematical models of the abutment made according to the literature data are very similar with the real abutment and the simplifications are minimal. These models enable calculations of stress and deformation of the dental structures. The finite element analysis provides useful information in understanding biomechanical problems and gives guidance for clinical research

Characterization and luminescence kinetics of Eu3+ doped YVO4 nanopowders

In this paper we describe the synthesis and characterization of the YVO4:Eu3+ nanopowder. The material was prepared using simple solution combustion synthesis. X-ray powder diffraction (XRD), scanning electron microscope (SEM), Raman and photoluminescence (PL) techniques were used to confirm and characterize the prepared material. The time resolved analysis of emission spectra was achieved by using the streak camera system. Beside luminescence lifetime of slow decayed transitions we also measured their rise time and lifetime of fast decayed transitions. We also determitied the excitation spectra of this nano material. Results of our analysis prove that YVO4:Eu3(+) nanopowder is appropriate material for various optoelectronic devices. (C) 2016 Elsevier Ltd. All rights reserved

Characterization and Optimization of Real-Time Photoresponsive Gelatin for Direct Laser Writing

There is an abundance of plastic materials used in the widest range of applications, such as packaging, machine parts, biomedical devices and components, etc. However, most materials used today are non-decomposable in the environment, producing a huge burden on ecosystems. The search for better, safer alternatives is still on. Here we present a detailed analysis of a simple, cheap, non-toxic, even edible, eco-friendly material, which can be easily manufactured, laser patterned and used for the fabrication of complex structures. The base substance is gelatin which is made photoresponsive by adding plasticizers and sensitizers. The resulting films were analyzed with respect to their optical, thermal and mechanical properties, which can be modified by a slight variation of chemical composition. The material is optimized for rapid laser-manufacturing of elastic microstructures (lenses, gratings, cantilevers, etc.) without any waste or residues. Overall, the material properties were tailored to increase photothermal responsivity, improve the surface quality and achieve material homogeneity, transparency and long-term stability (as verified using electron microscopy, infrared spectroscopy and differential scanning calorimetry)

Structural properties and luminescence kinetics of white nanophosphor YAG:Dy

Dysprosium (Dy3+ ions) doped YAG nanopowders were prepared by the solution combustion synthesis (SCS) method and undoped yttrium aluminum garnet (YAG, Y3Al5O12) single crystal was grown by the Czochralski technique. The structure of the prepared materials has been confirmed and characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM), Raman and photoluminescence (PL) spectroscopy. PL spectra were acquired using Optical Parametric Oscillator (OPO) excitation tuned at 350 nm. Several emission bands in Dy3+ emission spectrum were observed in the blue (470-500 nm), yellow (560-600 nm), red (660-685 nm) and infra-red (750-780 nm) regions, corresponding to F-4(9/2)-H-6(15/2), F-4(9/2)-H-6(13/2), F-4(9/2)-H-6(11/2), F-4(9/2)-(H-6(9/2) + H-6(11/2)) transitions in the 4f levels of Dy3+ ions, respectively. By using the Commission Internationale de lEclairage (CIE) chromaticity diagram of emission spectra it has been shown that this material can be used as a source of a white light. The result of lifetime analysis of the F-4(9/2) level in dysprosium ion has been reported, as well. (C) 2015 Elsevier B.V. All rights reserved

Effects of temperature and pressure on luminescent properties of Sr 2 CeO 4: Eu3+ nanophosphor

In this paper we describe the synthesis and characterization of the Sr2CeO4:Eu3+ nanopowder and possibilities of its application for temperature and high pressure sensing. The material was prepared using simple solution combustion synthesis. X-ray powder diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) techniques have been used to confirm and characterize the prepared material. Time resolved analysis of emission spectra was achieved by using the streak camera system. Measured lifetime values of luminescence emission and the intensity ratios of spectral lines were used for determining the calibration curves for remote temperature sensing. We have analyzed sensitivity improvement of the intensity ratio method by using a temporal evolution of emission lines and simulation of delayed gating of one of them. Pressure effects on optical properties of Sr2CeO4: Eu3+ nanophosphor are also investigated