53 resultados para Co2
Resumo:
Fundao de Amparo Pesquisa do Estado de So Paulo (FAPESP)
Resumo:
The use of biodiesel is increasing as an attractive fuel due to the depleting fossil fuel resources and environmental degradation. This paper presents results of an investigation on the potentials of biodiesel as an alternative fuel and main substitute of diesel oil, comparing the CO2 emissions of the main fuels in the Brazilian market with those of biodiesel, in pure form or blended in different proportions with diesel oil (2%, 5%, and 20%, called B2, B5, and B20, respectively). The results of the study are shown in ton CO2 per m(3) and ton CO2 per year of fuel. The fuels were analyzed considering their chemical composition, stoichiometric combustion parameters and mean consumption for a single vehicle. The fuels studied were: gasoline, diesel oil, anhydrous ethyl alcohol (anhydrous ethanol), and biodiesel from used frying oil and from soybean oil. For the case of biodiesel, its complete life cycle and the closed carbon cycle (photosynthesis) were considered. With data provided by the Brazilian Association of Automotive Vehicle Manufacturers (ANFAVEA) for the number of vehicles produced in Brazil, the emissions of CO2 for the national fleet in 2007 were obtained per type of fuel. With data provided by the Brazilian Department of Transit (DENATRAN) concerning the number of diesel vehicles in the last five years in Brazil, the total CO2 emissions and the percentage that they would decrease in the case of use of pure biodiesel, B100, or several mixtures, B2, B5 and B20, were calculated. Estimates of CO2 emissions for a future scenario considering the mixtures B5 and B20 are also included in this article. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
Resumo:
In this work we report on new optically pumped THz laser lines from deuterated formic acid (DCOOD). An isotopic (CO2)-C-13 laser was used for the first time as a pump source for this molecule, and a Fabry-Perot cavity was used as a THz laser resonator. Optoacoustic absorption spectra were used as a guide to search for new THz laser lines. We could observe six new laser lines in the range from 303.8 mu m (0.987 THz) to 725.1 mu m (0.413 THz). The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred lamb-dip technique was used to measure the frequency absorption transition for both of these laser lines. Furthermore, we also present a catalogue of all THz laser lines generated from DCOOD.
Resumo:
Avaliaram-se as alteraes do pH, da P O2 e da P CO2 do sangue arterial e da concentrao de lactato sangneo de 11 cavalos adultos da raa rabe, submetidos a exerccio progressivo em esteira de alta velocidade. Antes do exerccio, no intervalo dos 15 segundos finais de cada mudana de velocidade e aos 1, 3 e 5 minutos aps o trmino do exerccio foram coletadas amostras de sangue arterial e venoso para a mensurao dos gases sangneos e da concentrao de lactato. O exerccio resultou em diminuio do pH, da presso parcial de O2 (P O2) e da presso parcial de CO2 (P CO2). A concentrao de lactato sangneo elevou-se exponencialmente a partir da velocidade de 8,0m/s at os momentos aps trmino do exerccio.
Resumo:
Avaliou-se o efeito do enriquecimento da gua de irrigao com CO2 sobre ndices fisiolgicos de desenvolvimento e troca gasosa de folhas de plantas de pepino do tipo japons, cultivados em ambiente protegido. Os experimentos realizados em duas pocas do ano foram instalados em delineamento experimental de blocos ao acaso com 4 tratamentos e 5 repeties. Os tratamentos foram constitudos pelos hbridos Hokuho e Tsuyataro, irrigados com gua comum ou enriquecida com CO2, em uma concentrao de 1 no primeiro e 0,25 no segundo experimento. A produo de massa de material seco e rea foliar adotaram tendncia exponencial, no sendo possvel observar o incio da diminuio da taxa de produo de massa do material seco aos 63 dias aps transplante (DAT). A taxa de crescimento da comunidade e taxa de crescimento relativa do hbrido Hokuho irrigado com gua comum foi diferente do irrigado com gua enriquecida com CO2, no entanto, no hbrido Tsuyataro foram semelhantes. A taxa de assimilao lquida atingiu a mxima pendente na fase de crescimento vegetativo e florao, e foi reduzida drasticamente aps os 20 DAT no hbrido Hokuho, e aps os 35 DAT no hbrido Tsuyataro. A razo de rea foliar diminuiu ligeiramente nos dois hbridos com o desenvolvimento do cultivo. No incio observaram-se diferenas entre irrigao com gua comum e enriquecida com CO2, porm aps 20 DAT no se apreciaram mais diferenas. Quanto a troca gasosa, a taxa assimilatria lquida de CO2 e de transpirao, conductncia estomtica e eficincia no uso da gua foram semelhantes entre plantas irrigadas com gua comum e enriquecida com CO2 durante o primeiro semestre. J no segundo semestre, maiores valores foram registrados pelas plantas irrigadas com gua enriquecida.
Resumo:
Exposure of 1, 4, 7 & 10 day-old virgin queens of Apis mellifera Linne 1758 for 1 min to CO2 accelerated their ovarian development, having a similar effect as mating on the initial formation of the ovarian follicles. In 3 day-old queens the exposure to CO2 enhanced the initial stage of germ cell differentiation into oocytes and nurse cells in the ovarioles, a developmental stage only seen in 5 day-old untreated virgin queens, the age at which they are ready to mate. In 10 day-old untreated virgin queens, some regions of the ovarioles presented tissue disorganization and many cells with pycnotic nuclei. However, narcotized virgin queens of the same age did not present such ovary degeneration. Conversely, they showed nitid follicle formation, arising in the ovarioles' initial differentiation between nurse and oocytic chambers, although still without vitellogenesis. The accelerative effect of CO2 is limited to the ages near to those proper for mating, since 15 and 18 day-old treated virgin queens presented ovaries with extensive regions of high tissue disorganization and a great number of cells with pycnotic nuclei. According to the results, the narcosis presented three levels of effect on the ovary of honeybee virgin queens: 1) accelerated the germ cell differentiation, 2) preserved the tissue integrity even after the queen mating period and 3) stimulated the initial differentiation of a vitellarium. This later condition was only seen in untreated queens after mating. All these effects are not maintained if the queen is kept virgin beyond 15 days old.
Resumo:
Fundao de Amparo Pesquisa do Estado de So Paulo (FAPESP)
Resumo:
In order to study the relative roles of receptors in the upper airways, lungs and systemic circulation in modulating the ventilatory response of caiman (Caiman latirostris) to inhaled CO2, gas mixtures of varying concentrations of CO2 Were administered to animals breathing through an intact respiratory system, via a tracheal cannula by-passing the upper airways (before and after vagotomy), or via a cannula delivering gas to the upper airways alone. While increasing levels of hypercarbia led to a progressive increase in tidal volume in animals with intact respiratory systems (Series 1), breathing frequency did not change until the CO2 level reached 7%, at which time it decreased. Despite this, at the higher levels of hypercarbia, the net effect was a large and progressive increase in total ventilation. There were no associated changes in heart rate or arterial blood pressure. on return to air, there was an immediate change in breathing pattern; breathing frequency increased above air-breathing values, roughly to the same maximum level regardless of the level of CO2 the animal had been previously breathing, and tidal volume returned rapidly toward resting (baseline) values. Total ventilation slowly returned to air breathing values. Administration of CO2 via different routes indicated that inhaled CO2 acted at both upper airway and pulmonary CO2-sensitive receptors to modify breathing pattern without inhibiting breathing overall. Our data suggest that in caiman, high levels of inspired CO2 promote slow, deep breathing. This will decrease deadspace ventilation and may reduce stratification in the saccular portions of the lung.
Resumo:
The Locus coeruleus (LC) has been suggested as a CO2 chemoreceptor site in mammals. In the present study, we assessed the role of LC noradrenergic neurons in the cardiorespiratory and thermal responses to hypercapnia. To selectively destroy LC noradrenergic neurons, we administered 6-hydroxydopamine (6-OHDA) bilaterally into the LC of male Wistar rats. Control animals had vehicle (ascorbic acid) injected (sham group) into the LC. Pulmonary ventilation (plethysmograph), mean arterial pressure (MAP), heart rate (HR), and body core temperature (T-c, data loggers) were measured followed by 60 min of hypercapnic exposure (7% CO2 in air). To verify the correct placement and effectiveness of the chemical lesions, tyrosine hydroxylase immunoreactivity was performed. Hypercapnia caused an increase in pulmonary ventilation in all groups, which resulted from increases in respiratory frequency and tidal volume (V-T) in sham-operated and 6-OHDA-lesioned groups. The hypercapnic ventilatory response was significantly decreased in 6-OHDA-lesioned rats compared with sham group. This difference was due to a decreased V-T in 6-OHDA rats. LC chemical lesion or hypercapnia did not affect MAP, HR, and T-c. Thus, we conclude that LC noradrenergic neurons modulate hypercapnic ventilatory response but play no role in cardiovascular and thermal regulation under resting conditions.
Resumo:
Fundao de Amparo Pesquisa do Estado de So Paulo (FAPESP)
Resumo:
Keloids are considered to be benign hyperproliferative growths of dense fibrous tissue and overabundant deposition of disorganized, thick, hyalinized collagen that result from an abnormal tissue response to cutaneous injury. Keloids do not have a specific cause, although genetic predisposition is heavily implicated. We present a case report of a patient with an earlobe keloid that was treated with carbon dioxide laser radiation (CO2) with an 0.8-mm focus, 7 W, a power density of 2.5 W/cm(2), in a continuous mode. The patient was seen for follow-up 6 months later. An intact hole for placement of an earring was observed with a very good esthetic and functional result.
Resumo:
In this clinical study, we proposed to observe the efficacy of the treatment of squamous cell carcinoma of the tongue (SCCT) by carbon dioxide (CO2) laser surgery. Twelve patients with SCCT were treated with excisional surgery using the CO2 laser with a spot size of 0.8 mm, 10 W, power density of 2.5 W/cm(2) in continuous mode, and under constant vacuum removal of the plume. The post surgical clinical evaluations were done every day until the sutures were removed and then every 7 days up to 1 month postoperatively. Subjects were re-examined quarterly until the fifth year post surgery. After 5 yr of follow-up for all subjects, there was no recurrence of the SCCT at the involved sites. The functional and aesthetic results observed were excellent. It is concluded that CO2 laser ablation of SCCT is an extremely useful surgical technique that can provide a clean field and is capable of providing surgical results consistent with accepted principles of oncological surgery. (C) 2012 Laser Institute of America.
Resumo:
Fundao de Amparo Pesquisa do Estado de So Paulo (FAPESP)
Resumo:
Fundao de Amparo Pesquisa do Estado de So Paulo (FAPESP)