Centro Universitario do Norte Paulista

São José do Rio Preto, Brazil

Centro Universitario do Norte Paulista

São José do Rio Preto, Brazil
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Kobelnilk M.,Centro Universitario Do Norte Paulista | Fontanari G.G.,University of Sao Paulo | Cassimiro D.L.,São Paulo State University | Ribeiro C.A.,São Paulo State University | Crespi M.S.,São Paulo State University
Journal of Thermal Analysis and Calorimetry | Year: 2014

Coffee seeds are a source for obtaining oil which is used in the candy, soluble coffee, and cosmetics industries. The main purpose of this study was the investigation of the lipid profile and thermal behavior of the roasted and in nature coffee oil of Arabica and Robusta species, using thermogravimetry, differential thermal analysis, derivative thermogravimetry, differential scanning calorimetry (DSC), and modulated DSC. Details concerning the thermal decomposition as well as data of the kinetic parameters have been described here. The kinetic studies were evaluated from several heating rates with a sample mass of 10 mg in open crucible under nitrogen atmospheres. The obtained data were evaluated with the isoconversional kinetic method, where the values of activation energy (E a/kJ mol-1) were evaluated in function of the conversion degree (α). In addition, this oil was evaluated by modulated DSC from 25 to -60 C, where the transition phase behavior was verified. © 2013 Akadémiai Kiadó, Budapest, Hungary.


PubMed | Centro Universitario do Norte Paulista, University of Sao Paulo, New York University and Federal University of Rio Grande do Sul
Type: Journal Article | Journal: European journal of oral sciences | Year: 2016

This study evaluated the probability of survival (reliability) of platform-switched fixed dental prostheses (FDPs) cemented on different implant-abutment connection designs. Eighty-four-three-unit FDPs (molar pontic) were cemented on abutments connected to two implants of external or internal hexagon connection. Four groups (n=21 each) were established: external hexagon connection and regular platform (ERC); external hexagon connection and switched platform (ESC); internal hexagon and regular platform (IRC); and internal hexagon and switched platform (ISC). Prostheses were subjected to step-stress accelerated life testing in water. Weibull curves and probability of survival for a mission of 100,000 cycles at 400N (two-sided 90% CI) were calculated. The beta values of 0.22, 0.48, 0.50, and 1.25 for groups ERC, ESC, IRC, and ISC, respectively, indicated a limited role of fatigue in damage accumulation, except for group ISC. Survival decreased for both platform-switched groups (ESC: 74%, and ISC: 59%) compared with the regular matching platform counterparts (ERC: 95%, and IRC: 98%). Characteristic strength was higher only for ERC compared with ESC, but not different between internal connections. Failures chiefly involved the abutment screw. Platform switching decreased the probability of survival of FDPs on both external and internal connections. The absence in loss of characteristic strength observed in internal hexagon connections favor their use compared with platform-switched external hexagon connections.


Kobelnik M.,Centro Universitario Do Norte Paulista | Ribeiro C.A.,São Paulo State University | Dos Santos Dias D.,São Paulo State University | De Almeida S.,São Paulo State University | And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2011

The Co(II)-diclofenac complex was evaluated by simultaneous thermogravimetry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC). The DTA curve profile shows one exothermic peak because of the transition phase of the compound between 170 and 180 °C, which was confirmed by X-ray powder diffractometry. The transition phase behavior was studied by DSC curves at several heating rates of a sample mass between 1 and 10 mg in nitrogen atmosphere and in a crucible with and without a lid. Thus, the kinetic parameters were evaluated using an isoconversional non-linear fitting proposed by Capela and Ribeiro. The results show that the activation energy and pre-exponential factor for the transition phase is dependant on the different experimental conditions. Nevertheless, these results indicate that the kinetic compensation effect shows a relationship between them. © 2010 Akadémiai Kiadó, Budapest, Hungary.


Kobelnik M.,Centro Universitario Do Norte Paulista | Kobelnik M.,São Paulo State University | Cassimiro D.L.,São Paulo State University | De Almeida A.E.,São Paulo State University | And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2011

The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of 2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results in two kinetic behavior patterns. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Lofego A.C.,São Paulo State University | Rezende J.M.,São Paulo State University | Verona R.L.C.,Centro Universitario do Norte Paulista | Feres R.J.F.,São Paulo State University
Systematic and Applied Acarology | Year: 2013

The physic nut (Jatropha curcas L.) (Euphorbiaceae) has emerged as a new option in cultivation aimed at biodiesel production. In order to provide information that may be useful to further develop management plans for that specific crop, samples of mites were collected from cultured and wild J. curcas plants in various regions of the country and from two other species of the same genus, Jatropha gossypiifolia L. and Jatropha mollissima (Pohl) Baill. in the northeastern region of Brazil. Altogether 31 species belonging to 10 families were recorded. The family Phytoseiidae presented the largest number of species (17). Polyphagotarsonemus latus Banks (Tarsonemidae) was the most abundant species (8,503 specimens). A dichotomous key was prepared to identify all the sampled species. At least four mite species of the samples deserve attention as showing potential for being pests in the crops of J. curcas, Brevipalpus phoenicis, Brevipalpus obovatus, Polyphagotarsonemus latus and Tetranychus bastosi, the latter two often found in great abundance. © 2013 Systematic & Applied Acarology Society.


Kobelnik M.,Centro Universitario Do Norte Paulista | Cassimiro D.L.,São Paulo State University | Dos Santos Dias D.,São Paulo State University | Ribeiro C.A.,São Paulo State University | Crespi M.S.,São Paulo State University
Journal of Thermal Analysis and Calorimetry | Year: 2011

The jerivá is a well-known fruit, which belongs to the Arecaceae family, Syagrus romanzoffiana species frequently found in Brazil. Extraction of the jerivá oil was carried out, and the fatty acid profile of this oil indicates the linoleic and oleic acid presence, around 29.35 and 28.89%, respectively. Thermogravimetry (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were used to characterize this oil. Additionally, this oil was evaluated by DSC from 25 to -80 °C, and the crystallization behavior was verified. Details concerning the thermal behavior as well as data of kinetic parameters of these stages have been described here. The obtained data were evaluated, and the values were plotted in activation energy (E a/kJ mol -1) in function of the conversion degree (α). © 2011 Akadémiai Kiadó, Budapest, Hungary.


Kobelnik M.,Centro Universitario Do Norte Paulista | Cassimiro D.L.,São Paulo State University | Dos Santos Dias D.,São Paulo State University | Ribeiro C.A.,São Paulo State University | Crespi M.S.,São Paulo State University
Journal of Thermal Analysis and Calorimetry | Year: 2012

The araçá is a well-known fruit, which belongs to the Myrtaceae family, Psidium cattleianum Sabine species, frequently found in the southern region of Brazil. The extraction of araça oil was carried out from seeds, and the fatty acid profile of this oil indicates the predominant presence of linoleic acid (81.38%). Thermogravimetry, derivative thermogravimetry, and differential scanning calorimetry (DSC) were used to characterize this oil. In addition, this oil was evaluated by DSC from 25 to -60 C, where the crystallization behavior was verified. Details concerning thermal decomposition as well as data of kinetic parameters of these stages have been described here. The kinetic behavior of the thermal decomposition was evaluated from several heating rates with mass samples of 5 and 20 mg in open crucibles under nitrogen and synthetic air atmospheres. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Bernabe G.A.,São Paulo State University | Kobelnik M.,Centro Universitario Do Norte Paulista | Almeida S.,São Paulo State University | Ribeiro C.A.,São Paulo State University | Crespi M.S.,São Paulo State University
Journal of Thermal Analysis and Calorimetry | Year: 2013

The lignin and cellulose were extracted from reference material (leaves and twigs) and food of compost at different times composting: zero (raw), 30, and 120 days. According to thermogravimetric analysis and its derivative and differential scanning calorimetry curves for these samples, were verified during composting process there were considerable changes in its thermal profiles, as well as, characteristics lignin in cellulose samples and cellulose in lignin samples. These features were found by fourier transformed infrared spectroscopy. © 2012 Akadémiai Kiadó, Budapest, Hungary.


Kobelnik M.,Centro Universitario Do Norte Paulista | Cassimiro D.L.,São Paulo State University | Ribeiro C.A.,São Paulo State University | Capela J.M.V.,São Paulo State University | And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2012

The thermal behaviour of Mg-diclofenac compound was evaluated by simultaneous TG-DTA and DSC. The profile of the DSC curves showed that this compound possesses two transition phases: endothermic and exothermic between 170-180 °C and 185-195 °C, respectively. The endothermic reaction is reversible (enantiotropic). Thus, different experimental conditions, i.e. masses sample, open and crimped lids crucible, static and dynamic atmospheres were utilized for DSC analysis for evaluation of this transition phase. In a static atmosphere the enantiotropic reaction was not observed. The obtained data were utilized to obtain the kinetic parameters, which were calculated by the Capela and Ribeiro method. The results show that the activation energy for the transition phase depends on the different experimental conditions. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Rezende J.M.,São Paulo State University | Verona R.L.C.,Centro Universitario Do Norte Paulista | Lofego A.C.,São Paulo State University
Systematic and Applied Acarology | Year: 2016

Mite communities inhabiting crops are influenced by several environmental factors, e.g. rainfall, seasonality and the presence of weeds within the plantation. In this study, we seek to clarify the seasonality patterns of mite communities present in physic nut crops, Jatropha curcas L. (Euphorbiaceae), by evaluating the influence of these factors on the most abundant species found. We verified that Polyphagotarsonemus latus Banks (Tarsonemidae) and Tetranychus bastosi Tuttle, Baker & Sales (Tetranychidae), the most abundant phytophagous species, had random seasonality patterns in the physic nut crops. In the field, predatory species of natural occurrence were not able to control the population growth of phytophagous mite species. Also, the presence of weeds among physic nut crops increased the number of potential predators and the diversity of mite species in the agroecosystem. © Systematic & Applied Acarology Society.

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