940 resultados para FLASH


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This paper presents an assessment of an educational game for teaching the efficient use of electricity. Developed with Adobe Flash (R), it is a virtual board game where participants choose a car that starts the path and reaches the same final goal, going through a number of track steps defined in terms of a dice that each player rolls in turn. The car moves if the participant is able to correctly answer a question that is randomly generated by the software. The objective of the game is to answer questions related to energy efficiency promoting a healthy and attractive learning process for participants on concepts related to energy efficiency such as: the rational use of energy, the basic concepts of forms of energy generation, among others. The main objective of this paper is to assess the impact of the application of this virtual game in the teaching and learning process of high school students. Therefore, the game was applied in the discipline of physics in a class of junior high public school in the state of Sao Paulo. Initially, the class that had 43 students was divided into 10 groups of 4 students, and 1 group of 3 students. Each student group competed with one another. The idea was that each of them should indicate a student who was the representative of this group until only 4 group leaders were selected for the finals. At this stage, each student could interact with a group of up to ten students that acted as advisers. The adopted assessment process is based on the model proposed by Savi [7]. Then, at the end of the game, the students answered a prepared questionnaire based on the model proposed by Savi. According to Savi, although there are significant studies that show the importance of educational games for the process of cognitive development and learning concepts of students, there are few papers that present forms of assessing the potential of these resources. Thus, the assessment criteria proposed by Savi are based on the model of training evaluation by Kirkpatrick [3], taken as a reference to measure the efficiency of processes of continuing education courses for professionals. The authors assert that the metric of the evaluation proposed to assess the game is based on the first level of the model proposed by Kirkpatrick.

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Neste trabalho se propôs a utilização do MP3 player portátil para gravação de sinal nãoáudio em sua memória, utilizando-se seu recurso para gravação de voz. Para avaliar a proposta, retirou-se o microfone de eletreto do MP3 player e em seu lugar injetou-se um sinal de FM, com portadora de áudio de 1200 Hz modulada pelo sinal de interesse. O sinal é gravado no aparelho em arquivo no formato WAV. Sua recuperação se fez usando um demodulador de FM a PLL cuja entrada é o sinal de FM captado nos terminais da bobina do fone de ouvido do MP3 player. Nos testes, usou-se sinal senoidal e sinal de eletrocardiograma. Embora a qualidade dos sinais de baixa freqüência precise ser melhorada, em geral os resultados apontam para a viabilidade da proposta. Fazem-se sugestões para melhorias e extensões do trabalho.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Thermal annealings of amorphous gallium antimonide films were accompanied using Raman spectroscopy, both for stoichiometric and nonstoichiometric compositions. The films were prepared by flash evaporation on silicon substrates. Structural changes were induced by the heat treatments: an increasing degree of crystallization as a function of the annealing temperature is observed. Sb clusters are found to crystallize before GaSb does, and the dependence of the corresponding Raman peak intensity with the annealing temperature (occurring in two regimes) is explained. A mechanism for the crystallization of the amorphous GaSb is proposed, based on the prior migration of the Sb excess outside the GaSb region to be crystallized. © 1995 American Institute of Physics.

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Low-intensity laser has been used as a physical agent in various fields of medical sciences such as bone and tissue repair. Meanwhile little is known about its effects in adverse conditions such as abolition of load and osteopenic. With the assumption that the laser Ga-Al-As accelerates the process of bone consolidation, goal of this study was to evaluate bone mineral density (BMD) in incomplete transverse osteotomies of tibia in adult rats, treated with low power laser therapy in three different groups: G1 (n = 10), reference 15 days; G2 (n=10), suspended by the tail and, accordingly, treated with laser for 12 days; G3 (n = 10), suspended by the tail by 36 days and that after 21 days, there was laser treatment for 12 days. The right tibia treated with laser and left served as control. The laser was used to Ga-Al-As, DMC - Flash Lase® III, with wavelength 830nm, 100 mW, 4J, 140 J / cm ², 40s of application in 12 sessions. It was used densitometer-Lunar DPX®, with computer program for "small animals", and the analysis of BMD was made in the bone throughout the region and the osteotomy. The results showed no efficacy of laser therapy in the process of bone repair, both in animals of group 1, as in group 2 and 3. It follows that either the low-power laser was not an effective performance or the effects of laser therapy is not only manifested at the site of irradiation as well as the systemic level.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Matemática em Rede Nacional - IBILCE

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PURPOSE. To measure heterochromatic flicker electroretinograms (ERGs) at high (36 Hz) and intermediate (12 Hz) temporal frequencies to evaluate luminance and cone opponent responses, respectively, in glaucoma eyes with (perimetric) and without (preperimetric) visual field defects. METHODS. Flicker ERGs were recorded from one randomly chosen dilated eye of 32 patients (mean age, 61 +/- 11 years; 15 men, 17 women) from the Erlangen Glaucoma Registry and from 24 healthy volunteers (mean age, 43 +/- 11 years; 14 men, 10 women). Red and green light-emitting diodes in a Ganzfeld stimulator were sine wave-modulated in counterphase. The responses were measured at 36 Hz, the frequency at which ERGs reflect activity of the luminance pathway, and at 12 Hz, the frequency at which ERGs reflect chromatic activity. RESULTS. Response amplitudes were similar in glaucoma patients and controls. Phase differences were observed in patients with visual field defects (perimetric) compared with the control group at 36 and 12 Hz in the first harmonic and second harmonic responses. Patients without visual field defects (preperimetric) showed phase differences for the second harmonic component at 36 Hz. No age effect on response amplitudes and phases was found in any of the subject groups (controls and patients). CONCLUSIONS. The responses displayed phase differences but not amplitude differences in perimetric glaucoma patients at both 36 and 12 Hz, suggesting that both magnocellular and parvocellular pathways are affected. Preperimetric glaucoma patients also showed phase differences. The response phase may be sensitive to early dysfunction of the inner retina. (ClinicalTrials.gov number, NCT00494923.) (Invest Ophthalmol Vis Sci. 2011;52:6757-6765) DOI:10.1167/iovs.11-7538

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PURPOSE. To better understand the relative contributions of rod, cone, and melanopsin to the human pupillary light reflex (PLR) and to determine the optimal conditions for assessing the health of the rod, cone, and melanopsin pathways with a relatively brief clinical protocol. METHODS. PLR was measured with an eye tracker, and stimuli were controlled with a Ganzfeld system. In experiment 1, 2.5 log cd/m(2) red (640 +/- 10 nm) and blue (467 +/- 17 nm) stimuli of various durations were presented after dark adaptation. In experiments 2 and 3, 1-second red and blue stimuli were presented at different intensity levels in the dark (experiment 2) or on a 0.78 log cd/m(2) blue background (experiment 3). Based on the results of experiments 1 to 3, a clinical protocol was designed and tested on healthy control subjects and patients with retinitis pigmentosa and Leber`s congenital amaurosis. RESULTS. The duration for producing the optimal melanopsin-driven sustained pupil response after termination of an intense blue stimulus was 1 second. PLR rod-and melanopsin-driven components are best studied with low-and high-intensity flashes, respectively, presented in the dark (experiment 2). A blue background suppressed rod and melanopsin responses, making it easy to assess the cone contribution with a red flash (experiment 3). With the clinical protocol, robust melanopsin responses could be seen in patients with few or no contributions from the rods and cones. CONCLUSIONS. It is possible to assess the rod, cone, and melanopsin contributions to the PLR with blue flashes at two or three intensity levels in the dark and one red flash on a blue background. (Invest Ophthalmol Vis Sci. 2011; 52: 6624-6635) DOI: 10.1167/iovs.11-7586

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The present work employs a set of complementary techniques to investigate the influence of outlying Ru(II) groups on the ground- and excited-state photophysical properties of free-base tetrapyridyl porphyrin (H(2)TPyP). Single pulse and, pulse train Z-scan techniques used M association with laser flash photolysis, absorbance and fluorescence spectroscopy, and fluorescence decay measurements, allowed us to conclude that the presence of outlying Ru(II) groups causes significant changes on both electronic structure and vibrational properties of porphyrin. Such modifications take place mainly due to the activation of. nonradiative decay channels responsible for the emission, quenching, as well as by favoring some vibrational modes in the light absorption process, It is also observed that, differently from what happens when the Ru(II) is placed at the center of the macrocycle, the peripheral groups cause an increase of the intersystem crossing processes, probably due to the structural distortion of the ring that implies a worse spin orbit coupling, responsible for the intersystem crossing mechanism.

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The excited-state dynamics of free-base meso-tetrakis(sulfonatophenyl) porphyrin J-aggregates obtained by the Z-scan technique in femto- and picosecond time scales, along with UV-Vis spectroscopy and flash photolysis is reported. Besides obtaining the S-1 state lifetime, the discrimination between internal conversion and intersystem crossing nonradiative processes from that state was also possible, and their rates and respective quantum yields were found. The aggregates present reverse saturable absorption at 532 nm for both singlet and triplet excited states. The data shown is important for several applications such as optical limiting, photodynamic therapy and others. (C) 2011 Elsevier B.V. All rights reserved.

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Ground state interactions and excited states and transients formed after photolysis and photosensitization of 2-ethylaminodiphenylborinate (2APB) were studied by various techniques. The UV spectrum shows a large absorption band at 235 nm (epsilon = 14,500 M-1 cm(-1)) with a shoulder at 260 nm. The fluorescence spectra show increasing emission intensity with maximum at 300 nm, which shifts to the red up to 10(-3) M concentrations. At higher concentrations, the emission intensity decreases, probably due to the formation of aggregates. UV excitation in deareated solutions shows the formation of two transients at 300 and 360 nm. The latter has a lifetime of 5.7 mu s in ethanol and is totally quenched in the presence of oxygen and assigned to the triplet state of 2APB. The 300 nm peak is not affected by oxygen, has a lifetime in the order of milliseconds, and corresponds to a boron-centered radical species originated from the singlet state. A boron radical can also be obtained by electron transfer from triplet Safranine to the borinate (k(q) = 9.7 x 10(7) M-1 s(-1)) forming the semioxidized form of the dye. EPR experiments using DMPO show that dye-sensitized and direct UV-photolysis of 2ABP renders initially arylboron-centered radicals. (C) 2012 Elsevier B.V. All rights reserved.