10 resultados para Luz solar
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
In adolescents, who tend to sleep and wake-up later, the school schedule in the morning is associated with sleep advancement and shortening besides bedtime and wake-up time irregularity between week and weekend days. As a result, there is an increase in daytime sleepiness and a drop in cognitive performance that interfer in students performance in classroom. These consequences reinforce the need to evaluate alternatives that help the adolescent to adapt their sleep needs to the time of start of classes in the morning. Accordingly, the general aim of this study was to evaluate the effects of a sleep program education and sunlight exposure in early morning on sleep-wake cycle (SWC) and daytime sleepiness of adolescents. The students chronotype were evaluated by the Horne-Ostberg questionnaire and the health and usual sleep habits by "the health and the sleep questionnaire. The SWC patterns were assessed by sleep log, the daytime sleepiness by Karolinska Sleepiness Scale (KSS) and the alertness by the Psychomotor Vigilance Test (PVT). These parameters were compared before and after a sleep education program and before and during the sunlight exposure. The sleep program was effective in increasing sleep knowledge of adolescents, in promoting a reduction of bedtime and wake-up time irregularity and increasing the sleep duration in school days. The sunlight exposure effect was evaluated in the return to classes after vacation due to the difference in sleep patterns between school and vacation days. During the intervention week it was observed an advance of sleep schedules, an increase on sleep duration and alertness at the end of the morning. Assessed separately, sleep education and sunlight exposure should contribute to minimize adolescents partial sleep deprivation, but daytime sleepiness effect must be better investigated. These strategies should be used jointly by school members to improve health and performance of their students
Resumo:
The sleep onset and offset delay at adolescence in relation to childhood. Besides biological causes, some external factors as academic obligations and socialization contributes, increasing the burden of school and socialization. However, morning school schedules reduce sleep duration. Besides light strong effect, studies in humans have indicated that exercise influence circadian synchronization. To evaluate the effect of the morning exercise under sunlight on sleep-wake cycle (SWC) of adolescents, 160 high school students (11th year) were exposed to the following conditions: lesson in usual classroom (Group C), lesson in swimming pool exposed to sunlight (Group E), half of them carrying through physical activity (EE) and the other resting (EL). Each experimental group met two stages: assessment of SWC 1 week before and 1 week during the intervention, which was held in Monday and Wednesday between 7:45 and 8:30 am. In the baseline, there were applied the questionnaires "Health and Sleep" and cronotype evaluation (H & O). In addition, students were evaluated before and during the intervention by "Sleep Diary", "Karolinska Sleepiness Scale" (KSS), Psychomotor Vigilance Test (PVT) and actimetry. During the intervention, there was a delay in wake-up time on the weekend and a trend to greater sleep duration on week for the three groups. At the weekend, only the groups EE and EL increased sleep duration. There was no difference in bedtime, irregularity of sleep schedules and nap variables. The sleepiness showed a circadian pattern characterized by higher alertness levels at 11:30 am and sleepiness levels at bedtime and wake-up time on week. On weekends there were higher levels of alertness in these times. In the days of intervention, there was an increase of sleepiness at 11:30 am for groups EL and EE, which may have been caused by a relaxing effect of contact with the water of the pool. In addition, the group EE showed higher alert levels at 14:30 pm on Monday and at 8:30 am in the Wednesday, possibly caused by exercise arousal effect. The reaction time assessed through the TPV did not vary between the stages. The sleep quality improved in the three groups in the second stage, making impossible the evaluation of intervention effect. However, the sleep quality increased on Monday and Tuesday only on the group EE. From the results, it is suggested that the intervention promoted effects on the sleepiness at some day hours. In other SWC variables there were no effects, possibly due to a large SWC irregularity on weekends. Thus, the evaluation of higher weekly frequency EF is necessary, since only two days were insufficient to promote greater effect on adolescents SWC
Resumo:
The present work presents a contribution in the study of modelings of transference of heat for foods submitted to the experimental tests in the considered solar oven, where the best modeling for the beefburger of chicken in study was evaluated, comparing the results, considering this food as a half-infinite(1er object considered model) and,after that, considered the chicken beefburger as a plain plate in transient regimen in two distinct conditions: not considering and another model considering the contribution of the generation term, through the Criterion of Pomerantsev. The Sun, beyond life source, is the origin of all the energy forms that the man comes using during its history and can be the reply for the question of the energy supplying in the future, a time that learns to use to advantage in rational way the light that this star constantly special tax on our planet. Shining more than the 5 billion years, it is calculated that the Sun still in them will privilege for others 6 billion years, or either, it is only in the half of its existence and will launch on the Earth, only in this year, 4000 times more energy that we will consume. Front to this reality, would be irrational not to search, by all means technical possible, to use to advantage this clean, ecological and gratuitous power plant. In this dissertation evaluate the performance of solar cooker of the type box. Laboratory of Solar Energy of the Federal University of the Great River of North - UFRN was constructed by the group (LES) a model of solar stove of the type box and was tested its viability technique, considering modeling foods submitted when baking in the solar oven, the cooker has main characteristic the easiness of manufacture and assembly, the low cost (was used material accessible composition to the low income communities) and simplicity in the mechanism of movement of the archetype for incidence of the direct solar light. They had been proposals modeling for calculations of food the minimum baking time, considering the following models of transference of heat in the transient state: object the halfinfinite, plain plate and the model of the sphere to study the necessary temperature for the it bakes of bread (considering spherical geometry). After evaluate the models of transmission of heat will be foods submitted you the processes of to it bakes of, the times gotten for the modeling with the experimental times of it bakes in the solar oven had been compared, demonstrating the modeling that more good that it portraies the accuracies of the results of the model
Resumo:
The screening for genes in metagenomic libraries from soil creates opportunities to explore the enormous genetic and metabolic diversity of microorganisms. Rivers are ecosystems with high biological diversity, but few were examined using the metagenomic approach. With this objective, a metagenomic library was constructed from DNA soil samples collected at three different points along the Jundiaí-river (Rio Grande do Norte-Brazil). The points sampled are from open area, rough terrain and with the direct incidence of sunlight. This library was analyzed functionally and based in sequence. For functional analysis Luria-Bertani solid medium (LB) with NaCl concentration varied from 0.17M to 0.85M was used for functional analysis. Positives clones resistant to hypersaline medium were obtained. The recombinant DNAs were extracted and transformed into Escherichia coli strain DH10B and survival curves were obtained for quantification of abiotic stress resistance. The sequences of clones were obtained and submitted to the BLASTX tool. Some clones were found to hypothetical proteins of microorganisms from both Archaea and Bacteria division. One of the clones showed a complete ORF with high similarity to glucose-6-phosphate isomerase which participates in the synthesis of glycerol pathway and serves as a compatible solute to balance the osmotic pressure inside and outside of cells. Subsequently, in order to identify genes encoding osmolytes or enzymes related halotolerance, environmental DNA samples from the river soil, from the water column of the estuary and ocean were collected and pyrosequenced. Sequences of osmolytes and enzymes of different microorganisms were obtained from the UniProt and used as RefSeqs for homology identification (TBLASTN) in metagenomic databases. The sequences were submitted to HMMER for the functional domains identification. Some enzymes were identified: alpha-trehalose-phosphate synthase, L-ectoina synthase (EctC), transaminase L-2 ,4-diaminobutyric acid (EctB), L-2 ,4-diaminobutyric acetyltransferase (EctA), L-threonine 3 dehydrogenase (sorbitol pathway), glycerol-3-phosphate dehydrogenase, inositol 3-phosphate dehydrogenase, chaperones, L-proline, glycine betaine binding ABC transporter, myo-inositol-1-phosphate synthase protein of proline simportadora / PutP sodium-and trehalose-6-phosphate phosphatase These proteins are commonly related to saline environments, however the identification of them in river environment is justified by the high salt concentration in the soil during prolonged dry seasons this river. Regarding the richness of the microbiota the river substrate has an abundance of halobacteria similar to the sea and more than the estuary. These data confirm the existence of a specialized response against salt stress by microorganisms in the environment of the Jundiaí river
Resumo:
The screening for genes in metagenomic libraries from soil creates opportunities to explore the enormous genetic and metabolic diversity of microorganisms. Rivers are ecosystems with high biological diversity, but few were examined using the metagenomic approach. With this objective, a metagenomic library was constructed from DNA soil samples collected at three different points along the Jundiaí-river (Rio Grande do Norte-Brazil). The points sampled are from open area, rough terrain and with the direct incidence of sunlight. This library was analyzed functionally and based in sequence. For functional analysis Luria-Bertani solid medium (LB) with NaCl concentration varied from 0.17M to 0.85M was used for functional analysis. Positives clones resistant to hypersaline medium were obtained. The recombinant DNAs were extracted and transformed into Escherichia coli strain DH10B and survival curves were obtained for quantification of abiotic stress resistance. The sequences of clones were obtained and submitted to the BLASTX tool. Some clones were found to hypothetical proteins of microorganisms from both Archaea and Bacteria division. One of the clones showed a complete ORF with high similarity to glucose-6-phosphate isomerase which participates in the synthesis of glycerol pathway and serves as a compatible solute to balance the osmotic pressure inside and outside of cells. Subsequently, in order to identify genes encoding osmolytes or enzymes related halotolerance, environmental DNA samples from the river soil, from the water column of the estuary and ocean were collected and pyrosequenced. Sequences of osmolytes and enzymes of different microorganisms were obtained from the UniProt and used as RefSeqs for homology identification (TBLASTN) in metagenomic databases. The sequences were submitted to HMMER for the functional domains identification. Some enzymes were identified: alpha-trehalose-phosphate synthase, L-ectoina synthase (EctC), transaminase L-2 ,4-diaminobutyric acid (EctB), L-2 ,4-diaminobutyric acetyltransferase (EctA), L-threonine 3 dehydrogenase (sorbitol pathway), glycerol-3-phosphate dehydrogenase, inositol 3-phosphate dehydrogenase, chaperones, L-proline, glycine betaine binding ABC transporter, myo-inositol-1-phosphate synthase protein of proline simportadora / PutP sodium-and trehalose-6-phosphate phosphatase These proteins are commonly related to saline environments, however the identification of them in river environment is justified by the high salt concentration in the soil during prolonged dry seasons this river. Regarding the richness of the microbiota the river substrate has an abundance of halobacteria similar to the sea and more than the estuary. These data confirm the existence of a specialized response against salt stress by microorganisms in the environment of the Jundiaí river
Resumo:
The goal of the research was to investigate the energy performance of residential vertical buildings envelope in the hot and humid climate of Natal, capital of Rio Grande do Norte, based in the Technical Regulation of Quality for Energy Efficiency Level in Residential Buildings (RTQ -R), launched in 2010. The study pretends to contribute to the development of design strategies appropriate to the specific local climate and the increasing of energy efficiency level of the envelope. The methodological procedures included the survey in 22 (twenty two) residential buildings, the formulation of representative prototypes based on typological and constructives characters researched and the classification of the level of energy efficiency in the envelopment of these prototypes, using as a tool the prescriptive method of the RTQ-R and the parametric analyzes from assigning different values of the following variables: shape of the pavement type; distribution of housing compartments; orientation of the building; area and shading of openings; thermal transmittance, and solar absorptance of opaque materials of the frontage in order to evaluate the influence of these on the envelopment performance. The main results accomplished with this work includes the qualification of vertical residential buildings in Natal/RN; the verification of the adequacy of these buildings to local climate based from the diagnosis of the thermal energy of the envelopment performance, the identification of variables with more significant influence on the prescriptive methodology of RTQ-R and design solutions more favorable to obtain higher levels energy efficiency by this method. Finally, it was verified, that some of these solutions proved contradictory in relation to the recommendations contained in the theoretical approaches regarding environmental comfort in hot and humid weather, which indicates the need for improvement of the prescriptive method RTQ-R and further research on efficient design solutions
Resumo:
The present work concerns the use of shade elements as architectural elements to block sunlight in public buildings. In a city like Natal, (5o South) the incidence of sunrays in any type of design should be a constant concern for all the architects. Besides, this habit of avoiding insolation in the environment is not a common practice. Within this context, the present work has the objective to dig deep into the knowledge of solar control, studying some cases and verifying its function according to the orientation and the original design of the building, having in mind if the shade elements usually used in the region have achieved their purpose of providing protection against the incidence of direct sun rays. This study considers the position of the shade element (horizontal and vertical), the angle formed between them and the respective facades, and the local of the buildings in relation to their orientation during the summer, winter and equinox solstice. As supporting instruments the solar map of the city and the protractor, for measuring shade angles, were used. It was concluded that in all the cases studied, it was not possible to obtain the maximum use of the elements. It was verified that the best type of shade element (more efficient) for the city of Natal is the mixed type (horizontal and vertical) and that the vertical shade elements are more efficient in the early mornings and late afternoon. The horizontal shade elements are used more effective at midday. We intend to present the results of this study to the architects in the region in order to show them the correct ways of using the shade elements according to the possible orientation on the facade, as a supporting tool at the time of designing a project as well as a subsidy for further discussions on the elaboration of the new urban standards for the city of Natal/RN
Resumo:
Analogous to sunspots and solar photospheric faculae, which visibility is modulated by stellar rotation, stellar active regions consist of cool spots and bright faculae caused by the magnetic field of the star. Such starspots are now well established as major tracers used to estimate the stellar rotation period, but their dynamic behavior may also be used to analyze other relevant phenomena such as the presence of magnetic activity and its cycles. To calculate the stellar rotation period, identify the presence of active regions and investigate if the star exhibits or not differential rotation, we apply two methods: a wavelet analysis and a spot model. The wavelet procedure is also applied here to study pulsation in order to identify specific signatures of this particular stellar variability for different types of pulsating variable stars. The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifying rotation, magnetic activity, and pulsation signatures. We present the wavelet spectral composition and multiscale variations of the time series for four classes of stars: targets dominated by magnetic activity, stars with transiting planets, those with binary transits, and pulsating stars. We applied the Morlet wavelet (6th order), which offers high time and frequency resolution. By applying the wavelet transform to the signal, we obtain the wavelet local and global power spectra. The first is interpreted as energy distribution of the signal in time-frequency space, and the second is obtained by time integration of the local map. Since the wavelet transform is a useful mathematical tool for nonstationary signals, this technique applied to Kepler and CoRoT light curves allows us to clearly identify particular signatures for different phenomena. In particular, patterns were identified for the temporal evolution of the rotation period and other periodicity due to active regions affecting these light curves. In addition, a beat-pattern vii signature in the local wavelet map of pulsating stars over the entire time span was also detected. The second method is based on starspots detection during transits of an extrasolar planet orbiting its host star. As a planet eclipses its parent star, we can detect physical phenomena on the surface of the star. If a dark spot on the disk of the star is partially or totally eclipsed, the integrated stellar luminosity will increase slightly. By analyzing the transit light curve it is possible to infer the physical properties of starspots, such as size, intensity, position and temperature. By detecting the same spot on consecutive transits, it is possible to obtain additional information such as the stellar rotation period in the planetary transit latitude, differential rotation, and magnetic activity cycles. Transit observations of CoRoT-18 and Kepler-17 were used to implement this model.
Resumo:
The goal of the research was to investigate the energy performance of residential vertical buildings envelope in the hot and humid climate of Natal, capital of Rio Grande do Norte, based in the Technical Regulation of Quality for Energy Efficiency Level in Residential Buildings (RTQ -R), launched in 2010. The study pretends to contribute to the development of design strategies appropriate to the specific local climate and the increasing of energy efficiency level of the envelope. The methodological procedures included the survey in 22 (twenty two) residential buildings, the formulation of representative prototypes based on typological and constructives characters researched and the classification of the level of energy efficiency in the envelopment of these prototypes, using as a tool the prescriptive method of the RTQ-R and the parametric analyzes from assigning different values of the following variables: shape of the pavement type; distribution of housing compartments; orientation of the building; area and shading of openings; thermal transmittance, and solar absorptance of opaque materials of the frontage in order to evaluate the influence of these on the envelopment performance. The main results accomplished with this work includes the qualification of vertical residential buildings in Natal/RN; the verification of the adequacy of these buildings to local climate based from the diagnosis of the thermal energy of the envelopment performance, the identification of variables with more significant influence on the prescriptive methodology of RTQ-R and design solutions more favorable to obtain higher levels energy efficiency by this method. Finally, it was verified, that some of these solutions proved contradictory in relation to the recommendations contained in the theoretical approaches regarding environmental comfort in hot and humid weather, which indicates the need for improvement of the prescriptive method RTQ-R and further research on efficient design solutions
Resumo:
The present work concerns the use of shade elements as architectural elements to block sunlight in public buildings. In a city like Natal, (5o South) the incidence of sunrays in any type of design should be a constant concern for all the architects. Besides, this habit of avoiding insolation in the environment is not a common practice. Within this context, the present work has the objective to dig deep into the knowledge of solar control, studying some cases and verifying its function according to the orientation and the original design of the building, having in mind if the shade elements usually used in the region have achieved their purpose of providing protection against the incidence of direct sun rays. This study considers the position of the shade element (horizontal and vertical), the angle formed between them and the respective facades, and the local of the buildings in relation to their orientation during the summer, winter and equinox solstice. As supporting instruments the solar map of the city and the protractor, for measuring shade angles, were used. It was concluded that in all the cases studied, it was not possible to obtain the maximum use of the elements. It was verified that the best type of shade element (more efficient) for the city of Natal is the mixed type (horizontal and vertical) and that the vertical shade elements are more efficient in the early mornings and late afternoon. The horizontal shade elements are used more effective at midday. We intend to present the results of this study to the architects in the region in order to show them the correct ways of using the shade elements according to the possible orientation on the facade, as a supporting tool at the time of designing a project as well as a subsidy for further discussions on the elaboration of the new urban standards for the city of Natal/RN