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Juvenile Hormone (JH) is considered the main determinant of caste in social insects, though little is known about how this hormone acts in social wasps, especially the independent-founding species. The known relationship between JH titer and caste in the colony and we suggest a relationship among the effects of JH and the cuticular chemical profile. Therefore, this study aimed to test the hypothesis that topical application of JH to larvae of different instars alters the cuticular chemical composition of newly emerged females of Mischocyttarus consimilis (Zikán), influencing the dynamics of colony. Two techniques were used to evaluate the variation in cuticular chemical composition: Fourier transform infrared photoacoustic spectroscopy and gas chromatography coupled to mass spectrometry (GC-MS). Indeed, the application of JH did significantly alter the cuticular chemical composition of adult females that received treatment at the larval stage in comparison to control. The effects of JH were instar-dependent in that the results of topical application were significant when performed at third larval instar. Overall, these results add evidence that caste determination may, at least in part may be pre-imaginal in species of independent-founding social wasps.

Made available in DSpace on 2020-12-12T01:20:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-05 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This work has assessed the impact of copper oxide nanoparticles (CuONPs), designed via green route, toward photosynthetic apparatus on aquatic photoautotrophic organisms. In order to filling knowledge gaps, in vitro and in vivo assays were performed, using cyanobacterial phycocyanin (C-PC) from Arthrospira platensis and Lemna valdiviana plants (duckweed), respectively. Impairment in light energy transfer became evident in C-PC exposed to CuONPs, giving rise to an increase of light absorption and a suppression of fluorescence emission. Fourier transform infrared spectroscopy (FTIR) results showed that C-PC structures might be altered by the nanoparticles, also revealed that CuONPs preferably interacts with -NH functional groups. The data also revealed that CuONPs affected the chlorophyll a content in duckweed leaves. In addition, photosystem II (PSII) performance was significantly affected by CuONPs, negatively impacting the PSII photochemical network. In summary, the results point out that, even eco-friendly designed, CuONPs may negatively affect the photosynthetic process when accumulated by aquatic photoautotrophs. Natural Resources Program Center for Natural Resources Studies (CERNA) Mato Grosso do Sul State University (UEMS) Applied Optics Group Faculty of Science and Technology Federal University of Grande Dourados (UFGD) Department of Physics and Chemistry School of Engineering São Paulo State University (UNESP) Optics and Photonics Group Institute of Physics Federal University of Mato Grosso do Sul (UFMS) School of Life Science University of Essex Department of Physics and Chemistry School of Engineering São Paulo State University (UNESP)

In this work, thermal lens spectroscopy was performed simultaneously with photoluminescence experiments for determining the absolute external quantum efficiency (EQE) of luminescent materials. The procedure involved measurements of nonradiative (heat) and radiative (photon) emission rates after excitation of the material with a tunable laser. The main advantage of this combined methodology was that the amount of light absorbed by the sample was not required for EQE determination, which minimized the experimental error. In order to validate the methodology, the well-known Ce3+:YAG crystal was used for EQE determination, with the value obtained being in agreement with previous experiments. This shows that the method is a promising tool for accurate measurements of the EQE for materials with a single excited emission state.

At the present time there is no doubt that almost every country is experiencing a revolutionary change in the used devices for artificial lighting whether for public, for domestic or for work place illumination. This movement is taking place towards the substitution of fluorescent lamps to LED-phosphor based devices under the justification of reduction in energy consumption and mitigation of the contamination of environment produced by the mercury of fluorescent lamps. In this aspect, despite of the great effort of worldwide scientists to obtain a white lighting source with the emitting spectrum similar to that of the sunlight, it is recognized that there is still a challenge to be faced of getting luminescent materials with broad band excitation in the UV–Vis regions and large emission in the visible in order to allow tunable white lighting generation. Motivated by this interest, in this paper, Eu2+,3+/Pr3+ co-doped calcium aluminosilicate glasses were synthesized and spectroscopically investigated aiming at the development of smart white lighting devices. A prototype was developed to study the sample with excitation at 445 nm light emission diode (LED). The results indicate high color rendering index (CRI Ra ∼92–95) and tunable correlated color temperature (CCT from 5700 to 6600 K), covering the whole spectral daylight range. By using a second 405 nm LED together with the 445 nm one, the calculated Du’v’ values are suitable for indoor illumination. In this configuration, by adjusting the LEDs intensities it is possible to tune the CCT close to the white lighting region with CRI Ra nearly 95. These characteristics demonstrate that the Eu2+,3+/Pr3+ co-doped OH− calcium aluminosilicate glass is a strong candidate for smart white lighting with LEDs.

We report the first observation of laser cooling in Yb3+:KYW and validate the results by comparison with experiments in the well-studied material Yb3+:YAG. Radiation from a single-mode Ti:Al2O3 laser was used to achieve cooling of 1.5 K/W in 1% Yb:KYW at 1025 nm, comparing well with the reference material 3% Yb:YAG which cooled by 3.5 K/W at 1030 nm under open lab conditions. Experimental results for KYW crystals mounted on aerogels and doped with 1-20% Yb were in excellent agreement with the theoretical dependence of cooling power on the Yb absorption spectrum. Elimination of thermal conduction through the sample support structure was found to permit the attainment of lower temperatures and to simplify modeling of radiation balance conditions in self-cooled lasers with longitudinal thermal gradients. Contrary to the notion that more coolant ions yield higher cooling power, concentrations of Yb over 1% caused re-absorption of luminescence in KYW crystals, leading to a progressive red shift in the optimal cooling wavelength and the prevention of laser cooling altogether in a 20% sample at room temperature. The prospect of attaining radiation-balanced lasing in commercially-available tungstate crystals is evaluated.

In this work, the time dependence of the crude glycerol production was obtained experimentally in different reactions by fluorescence spectroscopy, and the curves were fitted by a new mathematical model, derived from rate equations, in order to elucidate the behavior of the compounds involved in transesterification reactions, including the speed and ester yield. The values were validated by comparison with the results of analyses performed using gas chromatography with flame ionization detection. The fitting of the glycerol fluorescence signal as a function of time by the proposed theoretical model was shown to be highly suitable for indicating the time at which the reaction should be stopped, hence minimizing costs and the time required for biodiesel production.

SUMMARY Objectives: To characterize the chemical interactions and analyze the interface of adhesive systems containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) and N-methacryloyl glycine (methacrylamide) functional monomers with the dentin in noncarious cervical lesions (NCCLs) compared with artificial defects (ADs). Methods and Materials: Twenty human teeth with natural NCCLs on the buccal surface were used. Class V cavities, similar to NCCLs, were created on the lingual surface to serve as controls. Teeth were randomly allocated to two groups according to the functional monomer in the adhesive (N=10): G1, 10-MDP; and G2, methacrylamide. NCCLs and ADs were characterized by their mineral composition (MC) and degree of demineralization (DD) using micro-Raman spectroscopy, adhesive/dentin chemical interactions (CIs) were assessed with infrared photoacoustic spectroscopy, and interface morphology was evaluated with scanning electron and light microscopy. MC, CI, and DD data were submitted to Shapiro-Wilk and Student t-tests (p Results: Compared with ADs, dentin in NCCLs was hypermineralized (p Conclusions: Results suggest that the G1 adhesive could be applied directly on the superficial sclerotic layer in NCCLs. In contrast, previous cavity preparation should be conducted to improve the micromechanical interaction of G2 with the dentin.

The use of silver nanoparticles (AgNPs) in commercial products has increased significantly in recent years. However, findings on the toxic effects of the AgNPs are still limited. This paper reports an investigation on the cytotoxic and genotoxic potential of the AgNPs on root cells of Allium cepa. Germination (GI), root elongation (REI), mitotic (MI), nuclear abnormality (NAI), and micronucleus index (MNI) were determined for seeds exposed to various AgNPs diameters (10, 20, 51, and 73 nm) as well as to the silver bulk (AgBulk) (micrometer-size particles) at the concentration of 100 mg·L−1. Transmission electron microscopy (TEM) provided the particle size distribution, while dynamic light scattering (DLS) was used to get the hydrodynamic size, polydispersity index, and zeta potential of the AgNPs. Laser-induced breakdown spectroscopy (LIBS) and inductively coupled plasma/optical emission spectrometry (ICP OES) were applied for quantifying the AgNPs content uptake by roots. Silver dissolution was determined by dialysis experiment. Results showed that the AgNPs penetrated the roots, affecting MI, GI, NAI, and MNI in meristematic cells. Changes in these indicators were AgNPs diameter-dependent so that cytotoxic and genotoxic effects in Allium cepa increased with the reduction of the particle diameter. The results also revealed that the AgNPs were the main responsible for the cytotoxicity and genotoxicity since negligible silver dissolution was observed.

During beer production, the mashing process is fundamental for extraction of the main sugars from the starch. The quantification of these fermentable sugars during the process provides a measure of the alcoholic content of the final beer. Therefore, monitoring of the sugar composition during beer production is very important for obtaining a quality product. This paper demonstrates the potential of white light interferometry (WLI) for monitoring the extraction of sugars in different mashing processes, by observing the refractive index of the mixture. All the mashings presented linear increases of the refractive index during the temperature steps, which were influenced by the concentrations of sugars produced in each step. Cauchy parameters obtained by refractive index interpretation showed the influence of carbohydrates on absorption in the infrared region, and amino acids on absorption in the ultraviolet region. Strong correlation was obtained between the refractive index and °Bx values, indicating that the WLI technique is a potential analytical method for monitoring the mashing process during beer production.

The 1o Scientific Symposium about Natural Resources (1o Simposio Cientifico sobre Recursos Naturais - SCRN) has as theme “Natural environmental and products: an interdisciplinary view”, and the main aim was encourage discussion among graduation and postgraduate students, and researchers with different disciplinary views, about the exploration, conservation and monitoring of natural resources, bringing out the importance of multidisciplinary actions in research to a responsible regional development. The event was a promotion of the Postgraduation Program in Natural Resource (Programa de Pos-graduacao em Recursos Naturais - PGRN) of the State University of Mato Grosso do Sul (Universidade Estadual de Mato Grosso do Sul - UEMS) and received financial supported by Foundation for Support the Development of Teaching, Science and Technology of Mato Grosso do Sul (Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul, Fundect). The event was organized in the following thematic scopes: 1) Applied materials development for natural resources; 2) Analytical methods and control for natural resources; 3) Valuation and characterization of natural environmental; 4) Environmental monitoring; 5) Natural products and derived from vegetal and animal origins; 6) Evaluation, systematic and chemistry ecology. In this special issue published in Orbital: The Electronic Journal of Chemistry the reader has a sample of the 250 works presented during four event days. To publish in this issue all participants were invited to submit a full paper following the journal Author Guidelines. Sandro Marcio Lima (UEMS) Chairman Claudia Andrea Lima Cardoso (UEMS) Guest Editor

Made available in DSpace on 2018-11-26T16:00:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 FUNDECT-MS Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) FINEP The synthesis of layered double hydroxides has been investigated aiming innumerous applications, mainly as adsorbent, catalyst and catalyst support materials, due their ability to adsorb anionic species and several aqueous soluble compounds. The carbonated magnesium-aluminium hydrotalcites are known as the main class of the layered double hydroxides and new composition are often characterized under the view point of thermal stability, crystallinity and catalytic performance for many reactions. Few trivalent cations are able to replace the aluminum one due the severe restriction for oxidation state and ionic radii, but the iron (III) one seems to be high potential to improve some of the characteristics required for that materials, such as specificity for built-rebuilt bonds in organic molecules. In this work, we have synthesized carbonated magnesium-aluminum hydrotalcite samples through the coprecipitation at pH 11 and investigate the Fe(III) insertion at 10 and 20 mol%. Thermal analysis, FTIR spectrometry and X-ray diffractometry techniques were used to understand the influence of the Fe(III) co-substitution, keeping the Mg(II) molar fraction invariable among the samples. We show the iron (III) insertion affects the dehydration and dehydroxylation processes due the changes in M-OH bond energies Very homogeneous structures were obtained for all of the samples dried at 100 degrees C and a consistent lattice volume expansion was observed as a function of iron (III) content, which can be required for catalyst or catalyst matrix applications. Univ Estadual Mato Grosso do Sul, CDTEQ, LIMAN, R Emilio Mascoli 275, BR-79950000 Navirai, MS, Brazil Univ Fed Mato Grosso do Sul, INQUI, Av Senador Filinto Muller 1555, BR-79064470 Campo Grande, MS, Brazil Univ Estadual Paulista, IQCar, CLIEC, Rod Araraquara Jau Km, BR-14800901 Araraquara, SP, Brazil Univ Estadual Paulista, IQCar, CLIEC, Rod Araraquara Jau Km, BR-14800901 Araraquara, SP, Brazil

We report the anomalous dispersion and group refractive index (ng) of the Er3+: tellurite glass measured by Windowed Fourier Transform from interferometric measurements and compared with the dispersion calculated from absorption spectra by known Kramers-Kroing relations.

Apiculture in Brazil is quite profitable and has great potential for expansion because of the favorable climate and abundancy of plant diversity. However, the occurrence of pests, diseases, and parasites hinders the growth and profitability of beekeeping. In the interior of the state of São Paulo, apiaries are attacked by ants, especially the species Camponotus atriceps (Smith) (Hymenoptera: Formicidae), which use the substances produced by Apis mellifera scutellata (Lepeletier) (Hymenoptera: Apidae), like honey, wax, pollen, and offspring as a source of nourishment for the adult and immature ants, and kill or expel the adult bees during the invasion. This study aimed to understand the invasion of C. atriceps in hives of A. m. scutellata. The individuals were classified into castes and subcastes according to morphometric analyses, and their cuticular chemical compounds were identified using Photoacoustic Fourier transform infrared spectroscopy (FTIR-PAS). The morphometric analyses were able to classify the individuals into reproductive castes (queen and gynes), workers (minor and small ants), and the soldier subcaste (medium and major ants). Identification of cuticular hydrocarbons of these individuals revealed that the eight beehives were invaded by only three colonies of C. atriceps; one of the colonies invaded only one beehive, and the other two colonies underwent a process called sociotomy and were responsible for the invasion of the other seven beehives. The lack of preventive measures and the nocturnal behavior of the ants favored the invasion and attack on the bees.

This study investigated the synthesis and structural characterization of two new polymeric frameworks based on metalorgano-chalcogenide materials. X-ray analyses revealed the frameworks of prepared compounds 1 and 2 to be polymeric chains achieved through Se–Hg intermolecular interactions. A detailed Raman evaluation of the compounds was performed, showing their synthetic precursors to constitute a safe and reproducible model for the assignment of the main vibrational modes of the molecules investigated. Complete characterization of 1 and 2 also included elemental analysis, IR spectroscopy, UV–Vis absorption data, and EDX analysis.

Made available in DSpace on 2018-11-26T16:17:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-01 Agencia Brasileira de Inovacao (FINEP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundacao de Apoio ao Desenvolvimento do Ensino, Ciencia e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT) Fish scales have been used to differentiate fish species and to give information on water pollution, besides others different purposes. In the present work, we are proposing, for the first time to our knowledge, to available the absorption from fish scales with Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) to assess the environmental integrity of different habitats. The infrared absorption measurements were performed directly on fish scales from the Astyanax altiparanae species, in order to check if the scales, and consequently the species, can be used as environmental bioindicator. The main absorption intensities were used as variables in the multivariate statistical analysis. It was noted that the chemical composition of the scales is directly related to the available food in the habitats, which is related to the integrity level of the environmental. The results point the fish scales as bioindicator to be applied with FTIR-PAS for monitoring aquatic ecosystems. (c) 2015 Elsevier B.V. All rights reserved. Univ Estadual Mato Grosso Sul, Programa Posgrad Recursos Nat, Dourados, MS, Brazil Univ Estadual Paulista, Dept Quim & Fis, BR-15385000 Ilha Solteira, SP, Brazil Univ Estadual Paulista, Dept Quim & Fis, BR-15385000 Ilha Solteira, SP, Brazil

In this work, fluorescence spectroscopy was used for the on-line in situ monitoring of the transesterification reaction of soybean oil with ethanol. Different excitation energies in the ultraviolet and visible regions were tested to find the most appropriate excitation wavelength to control the chemical reaction. The excitation wavelength of 532 nm was found to be the most interesting because the luminescence intensity is related to the crude glycerin byproduct, which is associated with the production of alkyl esters. At this excitation wavelength, the oil and biodiesel luminescence signals are minimal. The luminescence signal was monitored in different reactions to investigate its dependence on the temperature, catalyst mass concentration and alcohol:oil molar ratio relation. The methodology used is appropriate to optimize the production process, enabling determination of the best time to stop the reaction as well as the best parameters for the transesterification reaction.

The relationship between emission tunability and the local environment of europium ions in OH−-free calcium aluminosilicate glasses was investigated, focusing on the development of devices for artificial lighting. Significant conversion of Eu3+ to Eu2+ was obtained by means of melting the glasses under a vacuum atmosphere and controlling the silica content, resulting in broad, intense, and tunable luminescence ranging from blue to red. Electron spin resonance and X-ray absorption near edge structure measurements enabled correlation of the luminescence behavior of the material with the Eu2+/Eu3+ concentration ratio and changes in the surrounding ions' crystal field. The coordinates of the CIE 1931 chromaticity diagram were calculated from the spectra, and the contour maps showed that the light emitted from Eu2+ presented broad bands and enhanced color tuning, ranging from reddish-orange to blue. The results showed that these Eu doped glasses can be used for tunable white lighting by combining matrix composition and the adjustment of the pumping wavelength.

In the present paper the synthesis and optical characterization of iodinated acetophenone, 4-hydroxy-3-iodoacetophenone and 4-hydroxy-3,5-diiodoacetophenone obtained from 4-hydroxyacetophenone, were carried out. The optical features of iodinated molecules were determined by performing the UV-Vis absorption, fluorescence and thermal lens spectroscopies. The results showed that the optical properties of the 4-hydroxyacetophenone is altered when the iodine atom is inserted, as substituent, in the aromatic ring. Although it was determined that the optical feature was changed when one iodine atom was inserted in the aromatic ring (4-hydroxy-3-iodoacetophenone), the results revealed that emission behavior was strongly altered when two iodine atoms (4-hydroxy-3,5-diiodoacetophenone) were acting as substituents: the fluorescence quantum efficiency increases approximately 60%.

In this work we report the observed downconversion (DC) mechanism in Er 3+ /Yb 3+ -codoped tellurite glasses (in mol%, 80TeO 2 –10Li 2 O–10TiO 2 ). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in energy transfer from erbium to ytterbium. The visible Er 3+ fluorescence intensities decreased as a function of the Yb 3+ concentration, and there was a corresponding increase in the ytterbium emission at around 980 nm. Simultaneously, there was a reduction in the heat-generated due nonradiative decays (~21%) when ytterbium was added. This temperature change was measured by TLS measurements and the results corroborate with the indicated by spectroscopic interpretation.

Mashing is an enzymatic procedure for the extraction of sugars from malt. It has strong temperature dependence, so monitoring the sugar production is very important for optimization of the brewing process. In this work, Fourier transform infrared spectroscopy (FTIR) was used to monitor three different mashing programs. These all presented high concentrations of maltose and dextrin, enabling their differentiation according to the FTIR absorption bands at 991 and 1022 cm−1, characteristic of maltose and dextrin, respectively. The absorption intensities of these bands were used to monitor the concentrations of the compounds during mashing, and the values were compared to HPLC data. Multivariate analysis of variance was applied to the FTIR absorption intensities in order to separate groups corresponding to the temperature steps of each mashing program. The results demonstrated that infrared absorption offers an alternative to the HPLC method for monitoring the mashing process.

The aim of this study was to explore whether the nest chemical profile (NCP) can be used to determine intra- and interspecific differences in social wasps of the subfamily Polistinae. For this purpose, Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was used to directly analyze small pieces of nest as well as the gasters of females. An advantage of the methodology was that no sample preparation was required. FTIR-PAS combined with multivariate discriminant analyzes was used, to the best of our knowledge for the first time, to evaluate the NCPs of six species of polistine wasps, observing the influence of the nesting environment and investigating the relationships among the nest and female cuticular chemical profiles. The results revealed significant inter-species differences among the NCPs, as well as strong correlations with the environments in which the nests were located. The Mischocyttarus and Polistes species belong to the same tribe (Polistini) and therefore exhibited similar NCPs. These species were separated from the Polybia species in the NCP dendrogram, mainly because the Polybia belong to another tribe (Epiponini). Correlation was observed between the NCPs and the cuticular chemical profiles of females. The findings of the study demonstrated the importance of the NCP for differentiation of species and environments, and the utility of FTIR-PAS for identification of correlations between individuals and nests. The results confirmed the hypothesis that the NCP can be used as an additional tool for intra- and interspecific differentiation in social wasps of the subfamily Polistinae.

This work reports on the energy transfer efficiency for Nd3+/Yb3+ co-doped tellurite glasses (80TO2-20WO3, in mol%,). The correlation between Yb3+ ion concentration and the downconversion mechanism was investigated using optical and thermal lens spectroscopies, which enabled investigation of the radiative and nonradiative processes, respectively, involved in energy transfer from neodymium to ytterbium. The Nd3+ near-infrared fluorescence disappeared almost entirely when the maximum concentration of Yb3+ ions (4 mol%) was doped into the host. In contrast, there was a corresponding increase in the ytterbium emission at around 980 nm. When ytterbium was added, there was also a simultaneous reduction in the amount of heat generated by the sample due to a reduction in the nonradiative decay rate, corroborating the suspected high energy transfer efficiency of Nd3+→Yb3+. The results indicate that tungsten-tellurite glasses may be of potential use in solar cells for matching the solar emission spectrum to the semiconductor cell.

A fundamental feature in the evolution of social insects is the separation of castes, and the presence of wide differentiation between castes indicates a more advanced degree of sociability. In this study, we evaluated factors that indicate the reproductive status of females in colonies of the social wasp Polistes versicolor. The reproductive status of each female was examined by measuring nine morphometric characters, by the cuticular chemical profile, insemination and by her relative age. We conclude that in P. versicolor colonies there are 3 female groups that show cuticular chemical profile difference. The first group belong to females with ovarioles filamentous, typical of workers; the second is females with ovarioles intermediates; and the third is a group of queens, which are older females, inseminated and with greater degree of ovarian development found among all females. On the other hand, there was no significant morphological differences between these female groups. Therefore, although no significant morphological differences among females there are other factors such as the cuticular chemical composition that is an indicative of reproductive physiological condition of female in the colony.

Made available in DSpace on 2019-10-06T17:19:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul Lithium tellurite glasses with xTeO2 + (100 − x)Li2O nominal composition, where x = 95, 90, 85, 80, 75 and 70 mol%, have been prepared to investigate the dependence of the Te4+ emission as a function of the lithium modifier. Optical and structural properties of the glasses were explored by using UV–Vis absorption, photoluminescence and photoluminescence excitation spectroscopies, photoluminescence lifetime and Raman spectroscopy. Besides, the influence of Li2O in the glass structure was verified by density, glass transition temperature, thermal stability, glass-forming tendency, optical band edge and the number of non-bridging oxygen. The results support there is a good correlation between the glass structure and the Te4+ center concentration: the Li2O content contributes to increase the Te4+ in the glass structure. Grupo Vidros e Cerâmicas Universidade Estadual Paulista – UNESP Grupo de Espectroscopia Óptica e Fototérmica Universidade Estadual de Mato Grosso do Sul Laboratório de Laser e Aplicações Universidade de São Paulo Physics Department Faculty of Science Menofia University Grupo Vidros e Cerâmicas Universidade Estadual Paulista – UNESP Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 59/300.031/2015

Erbium doped tellurite glasses (TeO 2 + Li 2 O + TiO 2 ) were prepared by conventional melt-quenching method to study the influence of the Er 3+ concentration on the luminescence quantum efficiency ( η ) at 1.5 μm. Absorption and luminescence data were used to characterize the samples, and the η parameter was measured using the well-known thermal lens spectroscopy. For low Er 3+ concentration, the measured values are around 76%, and the concentration behavior of η shows Er–Er and Er–OH − interactions, which agreed with the measured lifetime values.

Ni0.04Zn0.96O and Fe0.03Zn0.97O with average diameter of 23 and 19 nm, respectively, have been syn- thesized by a modified solegel method to be used in the preparation of (100 � x)/x poly(vinyl alcohol)/ oxide nanocomposite films, with x ¼ 0,1, 3 and 5 (in wt.%). A 125 W-Hg vapor lamp with emission above 254 nmwas used to irradiate PVA/Ni0.04Zn0.96O and PVA/Fe0.03Zn0.97O films. The effect on their structural, thermal, morphological and optical properties was studied by TG, DSC, DRX, AFM, UVevis and PL spectrophotometry. The Ni0.04Zn0.96O addition on PVA films decreases the thermal stability of the polymer in inert and in oxidative atmosphere. In contrast, the Fe0.03Zn0.97O presence in the PVA films seems to increase the thermal stability of the polymer. The characteristic peak of the crystalline phase of PVA and wurtzite phase of the zinc oxide were identified through X-ray diffraction in both films. The crystallinity of the PVA film increases with UV irradiation and with the presence of Ni0.04Zn0.96O and Fe0.03Zn0.97O. The roughness of the PVA film was not modified by the addition of the doped oxides; however, it increases after UV irradiation, more significantly in the films containing the oxides. The PVA film exhibits absorption around 280 nm characteristic of pep* transitions related to carbonyl groups from residuals acetate, while the 95/05 PVA/Ni0.04Zn0.96O and 95/05 PVA/Fe0.03Zn0.97O nanocomposite films show absorption at the visible region which is characteristics of the band gap reduction of the doped oxides. The photoluminescence of PVA was modified by the presence of the oxides in the film. These nanocomposite films are interesting due to their thermal, mechanical (flexible) properties and low cost of production. In addition they are also able to exhibit peculiar optical properties showing potential to be used in photonic devices, gas sensors and organic solar cell applications.

Thermal lens (TL) spectroscopy in a dual-beam configuration was applied in a study on biodiesel and oil–biodiesel blends. The goal of this work was to evaluate the behavior of the thermal and mass diffusivities that arose when oil was added to biodiesel and to verify the capability of the method to identify small concentrations of triacylglycerol in biofuel. When transitioning from pure biodiesel to a blend consisting of 98% biodiesel and 2% soybean oil, the thermal diffusivity decreased 15% and the mass diffusivity increased 59%, which indicated that both parameters can provide significant information about the presence of oil in biodiesel. Therefore, TL spectroscopy can be a useful method for certifying the quality of biodiesel and biodiesel blends.

Facultative social parasitism has been recorded in several taxa of social insects. Most recently, this phenomenon has been recorded in colonies of the neotropical social wasp Mischocyttarus cerberus (parasitized by Mischocyttarus consimilis). This is the first case of interspecific parasitism described for the genus Mischocyttarus. How social parasites are able to remain in the host colony has been one of the central subjects of studies on this theme. Chemical signals are used by social insects to recognize their nestmates, which suggests that female parasites use a chemical strategy to hide their identity and become accepted as a member in host colonies. This study investigated the dynamics of cuticular hydrocarbons (CHs) of workers of M. consimilis and M. cerberus in both control and host colonies. Fourier Transform Infrared-Photoacoustic Spectroscopy (FTIR-PAS) was used to read the CHs; this technique is somewhat unusual but is quite reliable for this type of study. A stepwise canonical discrimination analysis detected significant differences between the mid-infrared spectra of the two species. This analysis provided a dispersion diagram of the results in order to differentiate the species, in which the first axis explained 61% of the results. These results demonstrated a clear difference in the CHs profile between non-conspecific workers from the control colonies. However, non-conspecific workers from the host colonies underwent a significant modification of CHs in comparison to the workers from the control colonies, and this modification was similar in all the host colonies non-conspecific workers. These data suggest that females of parasitic-specie modify the chemical profile of the host-specie females, and also alter their own profiles in order to be recognized as “nestmates” and to achieve success in parasitism.

SUMMARYSocial wasps can face many challenges during their colony cycle, including the presence of parasites. The order Strepsiptera is among the main parasites of the wasp genus Polistes. The aim of this study was to evaluate the effect of an endoparasite species on the host Polistes ferreri, with the hypothesis that females of this social wasp would undergo morphophysiological alterations as well as changes in their cuticular chemical profile caused by the obligate endoparasite. On average, parasitism was found in 10% of the colonies studied. All the parasitized females showed filamentous ovarioles without developing oocytes, which indicates a physiological castration. Moreover, the endoparasites present in the gaster of females caused its volume to increase, and the presence of endoparasites changed the cuticular chemical profiles of females, confirming our hypothesis. It is likely that this parasitism effect could hamper the maintenance of wasp colonies.

A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10−6 K−1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10−6 K−1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10−6, enabling precise spectroscopic characterization of materials across a wide spectral range.

From initial calcium aluminosilicate glass, transparent glass-ceramics have been successfully synthesized under simultaneous high pressure and temperature (SHPT). Possible homogeneous volumetric crystallization of this glassy system, which was not achieved previously by means of conventional heat treatment, has been put in evidence with a SHPT procedure. Structural, mechanical, and optical properties of glass and glass-ceramic obtained were investigated. Raman spectroscopy and X-ray diffraction allowed to identify two main crystalline phases: merwinite [Ca3Mg(SiO4)2] and diopside [CaMgSi2O6]. A Raman scanning profile showed that the formation of merwinite is quite homogeneous over the bulk sample. However, the sample surface also contains significant diopside crystals. Instrumented Berkovich nanoindentation was applied to determine the effect of SHPT on hardness from glass to glass-ceramic. For Eu-doped samples, the broadband emission due to 4f65d1 → 4f7 transition of Eu2+ was studied in both host systems. Additionally, the 5D0 → 7FJ transition of Eu3+ was used as an environment probe in the pristine glass and the glass-ceramic.

In situ micro-Raman spectroscopy was used to investigate the structural evolution of OH(-)-free calcium aluminosilicate glasses, under high pressure and at room temperature. Evaluation was made of the role of the SiO2 concentration in percalcic join systems, for Al/(Al + Si) in the approximate range from 0.9 to 0.2. Under high pressure, the intensity of the main band related to the bending mode of bridging oxygen ([Formula: see text][T-O-T], where T = Si or Al) decreased gradually, suggesting that the bonds were severely altered or even destroyed. In Si-rich glasses, compression induced a transformation of Q (n) species to Q (n-1). In the case of Al-rich glass, the Al in the smallest Q (n) units evolved from tetrahedral to higher-coordinated Al (([5])Al and ([6])Al). Permanent structural changes were observed in samples recovered from the highest pressure of around 15 GPa and, particularly for Si-rich samples, the recovered structure showed an increase of three-membered rings in the Si/Al tetrahedral network.

Eu 3+ and Eu 2+ co-doped calcium aluminosilicate glass–ceramics have been prepared by devitrification of calcium aluminosilicate glass using heat-treatment. Control of crystallization in the glass–ceramics was studied by X-ray diffraction (XRD) and Raman spectroscopy. The results showed that crystalline phases in glass–ceramic belong to the family of melilite Ca 2 Mg 0.25 Al 1.5 Si 1.25 O 7 as the major phase and anorthite CaAl 2 Si 2 O 8 as the minor phase. Luminescent properties were investigated by emission; lifetime and the color points were calculated. Emission spectra showed that Eu 2+ entered into the crystalline phase in a two steps mechanism: first as Eu 3+ which is then reduced to Eu 2+ . This incorporation in the crystal enhanced Eu 2+ emission with increasing time of heat-treatment and therefore crystallization.

One of the most important attributes that allowed the evolution and maintenance of sociality in insects is their ability to distinguish members of their own colonies. The capacity for individual recognition in social insects is mediated by chemical signals that are acquired soon after the adult emerges, and vary according to the tasks performed by individuals in their colonies. We determined the time when adults of the wasp Mischocyttarus consimilis acquire the chemical signature of their colonies, as well as the variation in the cuticular hydrocarbon profiles of the exoskeleton of individuals, according to their functions in the colony. The method used was Fourier transform infrared photoacoustic spectroscopy directly on the gaster of each individual. Young wasps take three to four days to acquire the colony's chemical signature, with a small change on the fifth day, when the cuticular hydrocarbon profile of the workers is more similar to that of the queens than that of the males, probably because they are of the same sex, but primarily because of the similarity of tasks executed by these two groups of females in the colonies.

In this paper, we report results concerning tunable light emission and color temperature in cerium-doped low-silica-calcium-alumino-silicate (LSCAS) glass for smart white-light devices. Spectroscopic results, analyzed using the CIE 1931 x – y chromatic diagram, show that this glass presents two broad emission bands centered at 475 and 540 nm, whose intensities can be tuned by the excitation wavelength. Moreover, the same emission can be achieved from a color temperature range from 3200 to 10,000 K, with a color-rendering index (CRI) of around 75% obtained by changing the optical path length of the sample. Our new phosphor LSCAS glass, which is a unique system that exhibits tunable yellow emission, combines all qualities for white-light devices.

ZnO nanoparticles with average diameter of 25 nm were synthesized by a modified sol–gel method and used in the preparation of (in wt.%) (100 − x) poly(vinyl alcohol) (PVA)/x ZnO nanocomposite films, with x = 0, 1, 2, 3, 4, and 5. The PVA/ZnO films were exposed to UV radiation for 96 h and their thermal, morphological, and spectroscopic properties were investigated. In inert atmosphere, the nanocomposite films showed lower thermal stability than the pure PVA film, and the calorimetric data suggest an interaction between PVA and ZnO in the nanocomposite films. Some crystalline phases could be seen in the films with ZnO, and a direct dependence on the ZnO concentration was also observed. The original structure of ZnO nanoparticles remained unaltered in the PVA matrix and they were uniformly distributed on the film surface. The roughness of the PVA film was not modified by the addition of ZnO; however, it increased after 96 h of UV irradiation, more significantly in the nanocomposite films. The films showed an absorption band centered at 370 nm and a broad emission band in the UV–vis region when excited at 325 nm.

Blends of biodiesel and diesel are being used increasingly worldwide because of environmental, economic, and social considerations. Several countries use biodiesel blends with different blending limits. Therefore, it is necessary to develop or improve methods to quantify the biodiesel level in a diesel/biodiesel blend, to ensure compliance with legislation. The optical technique based on the absorption of light in the mid-infrared has been successful for this application. However, this method presents some challenges that must be overcome. In this paper, we propose a novel method, based on fluorescence spectroscopy, to determine the biodiesel content in the diesel/biodiesel blend, which allows in loco measurements by using portable systems. The results showed that this method is both practical and more sensitive than the standard optical method.

In this work we report on the use of the Thermal Lens method to verify the evolution of the thermal diffusivity of sunflower and soybean vegetable oils utilized in preparation of twenty five snacks portions. Our results show that the thermal diffusivity for sunflower oil does not change between 1 and 25 portions of fried snacks. By another hand, the soybean thermal diffusivity exhibits a little decrease for higher portion of fried snacks, indicating that for this oil the triglyceride level is reduced as a degradation process.

As técnicas de lente térmica (LT) e \"Z-scan\" foram usadas para estudar as propriedades termo-óticas (difusividade térmica, condutividade térmica, taxa de variação do caminho ótico em função da temperatura e eficiência quântica de fluorescência) e não-lineares (partes real e imaginária do índice de refração não-linear, diferença de polarizabilidade e da seção de choque de absorção entre os estados excitado e fundamental, respectivamente) de sólidos dopados com Neodímio e Cromo. Uma nova extensão da técnica de LT foi proposta para determinar a eficiência quântica de fluorescência sem necessitar de amostra referência, como é feito na maioria dos métodos fototérmicos. Além disso, ambas técnicas foram usadas como espectroscopia, ou seja, a LT foi usada para estudar a forma de linha do calor gerado no material quando a excitação é feita próximo da banda de absorção do material, possibilitando assim a determinação da eficiência de transferência entre a matriz e o íon dopante, e a técnica \"Z-scan\" foi adaptada para medir a forma de linha do índice de refração não-linear próximo das linhas de emissão laser nos cristais dopados com Cromo. The Thermal Lens (TL) and Z-scan technique were used to study the thermo-optical (thermal diffusivity, thermal conductivity, temperature coefficient of the optical path length change and fluorescence quantum efficiency) and nonlinear optical (parts real and imaginary of the refractive index, polarizability difference and absorption cross section between the excited and ground states, respectively) properties of Neodymium and Chromium doped solids. A new extension of the TL technique was proposed to determine the fluorescence quantum efficiency without measuring a reference sample, as done by any photothermal method Moreover, both techniques were used as an spectroscopy one, i. e., the TL was used to study the line shape of the heat created in material when the excitation is done near at the host absorption band, allowing the determination of the energy transfer efficiency between the host and the dopant ion, and the 2-scan technique was adapted to measure the line shape of the nonlinear refractive index near the laser lines in Chromium doped crystals.

Neste trabalho, a técnica de Lente Térmica (LT) foi usada para determinar o valor absoluto da difusividade térmica (D), da condutividade térmica (K) e do coeficiente de temperatura do caminho óptico (ds/tD) de vidros fluoretos dopados com cobalto e neodímio, calcogenetos, calcohaletos (mistura de calcogenetos com haletos), aluminate de cálcio e de um cristal fluoreto. Estas medidas foram efetuadas na temperatura ambiente e próxima de Tg para algumas amostras. Para o vidro ZBLAN, realizamos experimentos de LT da temperatura ambiente até ~ 330°C, observando um grande decréscimo de D na região de transição do vidro (Tg ~ 290°C). Nós também aplicamos a técnica de LT para determinar a eficiência quântica fluorescente do ZBLAN dopado com Nd+3. A utilidade desta técnica para determinar as propriedades termo-ópticas dos materiais transparentes em função da temperatura foi demonstrado. In this work the Thermal Lens (TL) technique was used to determine the absolute values of the thermal diffusivity (D), thermal conductivity (K) and temperature coefficient of the optical path length (ds/dT) of fluoride, chalcogenide, chalcohalide (chalcogenides and halides mixture) and calcium aluminate glass and of a fluoride cristal. These measurements were developed at ambient temperature and near Tg for some samples. For the ZBLAN glass, we performed the TL experiment from ambient to ~ 330°C, observing na abrupt decrease on D close to the glass transition temperature (Tg ~ 290°C). We also applied the TL technique to determine the fluorescence quantum efficiency of Nd+3 doped ZBLAN. The usefulness of this technique to determine thermo-optical properties of transparent materials as a function of the temperature was demonstrated.

Made available in DSpace on 2018-12-11T16:39:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-25 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) In this work, we investigate the spectroscopy properties of neodymium doped tungsten-tellurite glasses prepared in ambient and O2-rich atmospheres. A conversion of TeO4 to TeO3 units was caused by the addition of Nd3+ into the glass, which was confirmed by absorption spectra and by Judd-Ofelt parameter behavior. The relaxation of the 4F3/2 level is dominated by radiative decay and cross-relaxation between Nd3+ and Nd3+ ions. The energy transfer from Nd3+ to the hydroxyl group is negligible when compared to the cross-relaxation. The luminescence quantum efficiency values of the 4F3/2 level decreases as the Nd3+ concentration increases, independently if determined by the Judd-Ofelt method or by the thermal lens technique. The observed reduction in the IR absorption associated to OH groups was not effective to improve the luminescence quantum efficiency. Faculdade de Engenharia, UNESP - Univ Estadual Paulista, Campus de Ilha Solteira Laboratório de Laser e Aplicações, IFSC UFGD Grupo de Espectroscopia Óptica e Fototérmica, UEMS Faculdade de Engenharia, UNESP - Univ Estadual Paulista, Campus de Ilha Solteira CAPES: 042/2010 CNPq: 305063/2012-0 CNPq: 445286/2014-8

Studies related to communication on spiders show that, as in other invertebrates, the interactions between conspecifics are also made through chemical signals. Therefore, in order to assess whether the composition of cuticular compounds might be involved in interactions that occur during the days after the emergence of juveniles in Latrodectus geometricus, we conducted behavioral and cuticular chemical profiles analysis of females and juveniles of different ages. The results show that females, regardless of their reproductive state, tolerate juveniles of other females with up to 40 days post-emergence and attack juveniles of 80 days post-emergence. Cuticlar chemical analysis shows that while the profile of juveniles is similar to adult's profile, they can remain in the web without being confused with threat or prey. Also, cuticular chemical profiles vary between different populations probably due to genetic and environmental differences or similarities between them. Finally, females in incubation period are able to detect the presence of eggs within any egg sac, but cannot distinguish egg sacs produced by conspecifics from the ones they had produced.

In this work, low-cost substrates with rough silver surfaces were prepared from commercial copper foil-covered phenolic board (CPB) and an aqueous solution of AgNO3, and were used for surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS) measurements. A maximum SERS amplification factor of 1.2 × 107 was obtained for Rhodamine 6G (R6G), and use of the CPB resulted in a detection limit for Thiram pesticide of 0.5 µmol L−1. The minimum detection level was limited by residual traces of phenolic groups that originated from the substrate resin, which became solubilized in the aqueous Ag+ solution. It was found that the bands corresponding to the impurities had less influence in the Thiram analysis, which could be explained by the high affinity of sulfur for Ag surfaces. The influence of impurities in the SERS analyses therefore depended on the linkage between the rough silver surface and the analyte. The findings demonstrated the ease and effectiveness of using CPB to prepare a nanostructured surface for SERS.

Wasps are able to synthesize toxic compounds known as venoms, which form a part of a mechanism to overcome prey and also to defend their colonies. Study of the compounds that constitute these substances is essential in order to understand how this defense mechanism evolved, since there is evidence that the venoms can vary both intra- and interspecifically. Some studies have used liquid and gas chromatography as a reliable technique to analyze these compounds. However, the use of Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) to analyze the variations in venom's chemical profile has been proposed recently. This study evaluated whether the FTIR-PAS technique is effective for assessing the role of environmental factors on intra- and interspecific differences in the venom of the wasps Polybia paulista Von Ihering and Polybia occidentalis Olivier by FTIR-PAS. The colonies were collected in three municipalities of Mato Grosso do Sul, Brazil, in different types of environments. The results showed that the venoms of P. paulista and P. occidentalis differed significantly in profile. In addition, the intraspecific differences in the venom's chemical profile of P. paulista are related to the type of environment where they nested, regardless of the geographical distance between the nests. The FTIR-PAS technique proved to be reliable and effective to evaluate the variations in the venom's chemical profile in social wasps.

In this paper, the application of thermal lens and Z-scan techniques to the study of the thermo-optical and spectroscopic properties of solid-state laser glasses is described. The theoretical basis for quantitative measurements of thermal diffusivity and conductivity, temperature coefficient of the optical path length change, heat efficiency, fluorescence quantum efficiency, losses mechanisms (Auger upconversion and concentration quenching) and the line shape of the nonlinear refractive index are presented and discussed. The electronic contribution to the nonlinearity was investigated using the Z-scan technique in the time-resolved mode. The measurements were performed spectroscopically, allowing the determination of the line shapes of real and imaginary parts of the nonlinear refractive index, n2, in resonance with laser transitions. The results were interpreted by considering resonant and nonresonant contribution to n2. The magnitude of electronic and thermal contributions to the refractive index changes in solid-state laser glasses were also compared, and the thermal properties as a function of the temperature in the range of 20 up to 600 K are presented.

In this work the thermal lens, thermal relaxation calorimetry and interferometric methods are applied to investigate the thermo-optical properties of tellurite glasses (in mol%: 80TeO 2 –20 Li 2 O(TeLi), 80TeO 2 –15Li 2 O–5TiO 2 (TeLiTi-5) and 80TeO 2 –10Li 2 O–10TiO 2 (TeLiTi-10)). Thermal diffusivity, thermal conductivity, specific heat and the temperature coefficients of refractive index, optical path length, thermal expansion and electronic polarizability were determined. The use of three independent methods was useful for a complete characterization of the studied tellurite glasses. In addition, our results showed that the thermal expansion coefficient and the temperature coefficient of the optical path length (d S /d T ) were significantly modified with the introduction of titanium, which may be relevant for the application of these glasses in the photonic area.

In this work, a method based on thermal lens spectrometry is proposed to determine the fluorescence quantum efficiency (η) of the 3 F 4 level (∼1.8μm emission) of Tm-doped solids. It was applied to Tm-doped water free low silica calcium aluminate glasses. The obtained η value for the glasses with high Tm content was approximately 30 %, which is in agreement with the achieved η values from ratio between radiative and experimental lifetimes.

In this work we determine the thermo-optical properties of two chalcogenide glasses (in mol%): 65 Ga 2 S 3 ; 30 La 2 S 3 ; 5 La 2 O 3 (Ga:La:S) and 72.5 Ga 2 S 3 ; 27.5 La 2 O 3 (Ga:La:S:O). The thermal relaxation calorimetry and the thermal lens technique were combined so that the samples specific heat, thermal diffusivity, thermal conductivity, and the temperature coefficient of the optical path length change could be measured. Our results indicate that changes in thermal diffusivity (∼2.7 × 10 −3 cm 2 /s) and conductivity (∼4.8 × 10 −3 W/K cm) observed when La 2 O 3 is added in the glass compounds are less than the error in the data.

An interferometric technique was used to determine the temperature coefficient of the optical path length (dS/dT) as a function of the temperature in several optical glasses. The temperature range was between 25 � C and 180 � C. The studied samples included undoped and doped oxide glasses, such as low silica calcium aluminosilicate, phosphates, borates and also chalcogenides. The oxide glasses had dS/dT between 10 · 10 � 6 K � 1 and 20 · 10 � 6 K � 1 , while for the chalcogenides, these were around 70 · 10 � 6 K � 1 . The results showed that dS/dTs increased with the temperature in all samples. For samples doped with Nd the dS/dT values were found to be independent of concentration. On the other hand, for the phosphate glass doped with Cr, dS/dT increased about 5% when compared with the Nd doped one. In conclusion, the used interferometric method, which is a considerably simpler and a lower cost technique, and is a useful tool to measure dS/dT in semi-transparent glasses as a function of the composition and temperature. � 2004 Elsevier B.V. All rights reserved.