1,367 research outputs found
Compatible blends of thermoplastic starch and hydrolyzed ethylene-vinyl acetate copolymers
AbstractEthylene-vinyl acetate copolymer (EVA) with 19% of vinyl acetate and its derivatives modified by hydrolysis of 50 and 100% of the initial vinyl acetate groups were used to produce blends with thermoplastic starch (TPS) plasticized with 30wt% glycerol. The blends were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, water absorption, stress–strain mechanical tests, dynamic mechanical analysis and thermogravimetric analysis. In contrast to the blends with unmodified EVA, those made with hydrolyzed EVA were compatible, as demonstrated by the brittle fracture surface analysis and the results of thermal and mechanical tests. The mechanical characteristics and water absorption of the TPS were improved even with a small addition (2.5wt%) of hydrolyzed EVA. The glass transition temperature rose with the degree of hydrolysis of EVA by 40 and 50°, for the EVA with 50 and 100% hydrolysis, respectively. The addition of hydrolyzed EVA proved to be an interesting approach to improving TPS properties, even when very small quantities were used, such as 2.5wt%
Effects of the Energy Error Distribution of Fluorescence Telescopes on the UHECR energy spectrum
The measurement of the ultra high energy cosmic ray (UHECR) spectrum is
strongly affected by uncertainties on the reconstructed energy. The
determination of the presence or absence of the GZK cutoff and its position in
the energy spectrum depends not only on high statistics but also on the shape
of the energy error distribution. Here we determine the energy error
distribution for fluorescence telescopes, based on a Monte Carlo simulation.
The HiRes and Auger fluorescence telescopes are simulated in detail. We analyze
the UHECR spectrum convolved with this energy error distribution. We compare
this spectrum with one convolved with a lognormal error distribution as well as
with a Gaussian error distribution. We show that the energy error distribution
for fluorescence detectors can not be represented by these known distributions.
We conclude that the convolved energy spectrum will be smeared but not enough
to affect the GZK cutoff detection. This conclusion stands for both HiRes and
Auger fluorescence telescopes. This result differs from the effect of the
energy error distribution obtained with ground detectors and reinforces the
importance of the fluorescence energy measurement. We also investigate the
effect of possible fluorescence yield measurement errors in the energy
spectrum.Comment: 24 pages, 11 figure
Size matters: fishing less and yielding more in smaller-scale fisheries
Several factors influence catches and the sustainability of fisheries, and such factors might be different depending on the scale on which fisheries
work. We investigated the existence of possible subdivisions within small-scale fisheries (SSF) themselves, regarding their economic performance
and relative social and environmental impacts to understand which categories of these two types of fleets are best positioned to support sustainability. By doing so, we investigated if it is a good strategy for SSF to aim to grow towards larger scales. We obtained economic and ecological data
from landing samplings and information on technological efficiency of this fleet, using a northeastern Brazilian state as a case study. We defined a
cut-off point to separate the SSF into two categories of boats, according to their size and gear. We compared their cpue and the factors affecting it
within each category; we also compared economic (number of boats, number of landings, jobs, gears, catch, travel time and total time of the fishery,
revenues, costs, profits, revenue per unit of effort, and profit per unit of effort) and ecological factors (vulnerability of species caught) between the
two categories. We found that small boats spent less time fishing and employed comparatively more people per landed value and catch. The cpue
and profits of small boats were also higher. Both large and small boats exploit species with the same overall vulnerability. Therefore, being smaller,
even within the SSF category, seems to be a more advantageous social and economic strategy for guaranteeing higher catches and more employment opportunities per catch. These findings need to be taken into account when defining new policies, such as the distribution of subsidies that
support or not the sustainable use of fishery resources
Trabalhadores Usuários De Drogas Em Recuperação Em Uma Região Industrial Do Brasil
Context: The number of illicit drug users worldwide is estimated at 210 million people annually, of which at least 200,000 die as a result. Drug abuse affects not only the user but also their family, friends, coworkers, and community. Objective: This study outlines a sociodemographic profle of workers undergoing treatment for chemical dependency recovery in Campinas (SP). Method: Cross-sectional, exploratory study with data collected in rehabilitation centers for chemical dependency treatment in Campinas by means of a self-administered and anonymous questionnaire. The research was conducted between July 2011 and July 2012 and focused on the analysis of health and work conditions. The study included workers who were followed for more than 30 days (n=200). Results: 87.8% of the population were aged 18-54 years. Most of them had completed high school, had an income of some kind, and of which 54.5% were formally employed. 48.4% hadcontract positions of less than one year and 42.1% had a salary range below R$1,020.00 (Brazilian real). Conclusion: This study provides information not explored in other studies and has a potential value related to the prevention, treatment, and rehabilitation of workers in similar conditions.142788
Recommended from our members
Remote system for detection of low-levels of methane based on photonic crystal fibres and wavelength modulation spectroscopy
In this work we described an optical fibre sensing system for detecting low levels of methane. The properties of hollow-core photonic crystal fibres are explored to have a sensing head with favourable characteristics for gas sensing, particularly in what concerns intrinsic readout sensitivity and gas diffusion time in the sensing structure. The sensor interrogation was performed applying the Wavelength Modulation Spectroscopy technique, and a portable measurement unit was developed with performance suitable for remote detection of low levels of methane. This portable system has the capacity to simultaneously interrogate four remote photonic crystal fibre sensing heads. Copyright © 2009 J. P. Carvalho et al
TOPOGRAFIA DOS COLATERAIS CALIBROSOS DO ARCO AÓRTICO DE UM MÃO - PELADA (Procyon cancrivorus GRAY, 1865) (CARNIVORA PROCYONIADAE)
Estudou-se a topografia dos colaterais calibrosos do arco aórtico em um exemplar de
Procyon cancrivorus, adulto, macho, proveniente da Fazenda Experimental do Glória, da Universidade
Federal de Uberlândia, MG, Brasil, o qual teve seus vasos arteriais injetados com solução corada de
Neoprene Latex 450, com posterior fixação em solução aquosa de formol a 10% e submetidos à
dissecação. O arco aórtico encontra-se em correspondência à terceira costela, no antímero esquerdo
da cavidade torácica. O primeiro ramo calibroso do arco aórtico é o tronco braquiocefálico, situado
medialmente à terceira costela, originando as artérias carótida comum esquerda, carótida comum
direita e a subclávia direita, em correspondência ao primeiro espaço intercostal. A artéria subclávia
esquerda é o segundo ramo emergente do arco aórtico, originando-se medialmente à terceira costela.
As artérias subclávias direita e esquerda, cedem os mesmos colaterais em ambos os antímeros, ou
seja, tronco costocervical esquerdo (medialmente à primeira costela), tronco costocervical direito
(borda cranial da primeira costela), artérias cervical superficial esquerda e cervical superficial direita
(borda cranial da primeira costela), artéria torácica interna esquerda (medialmente à segunda costela)
e artéria torácica interna direita (borda cranial da primeira costela).
The topography of the thick collaterals of the aortic arch in a crab
eating raccoon Procyon cancrivorus Gray, 1865, Carnivora Procyoniadae
Abstract
An anatomical study has been carried out on the topography of the thick collateral
branches of the aortic arch in an adult male specimen of raccoon (Procyon cancrivorus) from the
Gloria Experimental Farm, Federal University of Uberlandia MG, Brasil. For this purpose, the arterial
blood vessels were injected with a ruddy solution of Neoprene Latex 450, fixed by means of a 10%
aqueous solution of formaldehyde and then dissected. It has been observed that the aortic arch is in
correspondence with the third rib at the left side of the thoracic cavity The first thick branch of the aortic
arch is the brachiocephalic trunk which is situaded medially in regard to the third rib, originating the left
common carotid artery, the right common carotid artery and the right subclavian artery in correspondence
with the first intercostal space. The left subclavian artery is the second emerging branch of the aortic
arch originating itself medialy to the third rib. The right and the left subclavian arteries give way to the
same collaterals in both sides, as the left costocervical trunk (medially to the first rib), the right
costocervical trunk (cranial edge of the first rib), the left and the right superficial cervical arteries (cranial
edge of the first rib, the left internal thoracic artery (medially to the second rib), and the right internal
thoracic artery (cranial edge of the first rib)
Future environmental and agricultural impacts of Brazil's Forest Code
The role of improving the enforcement of Brazil's Forest Code in reducing deforestation in the Amazon has been highlighted in many studies. However, in a context of strong political pressure for loosening environmental protections, the future impacts of a nationwide implementation of the Forest Code on both environment and agriculture remain poorly understood. Here, we present a spatially explicit assessment of Brazil's 2012 Forest Code through the year 2050; specifically, we use a partial equilibrium economic model that provides a globally consistent national modeling framework with detailed representation of the agricultural sector and spatially explicit land-use change. We test for the combined or isolated impacts of the different measures of the Forest Code, including deforestation control and obligatory forest restoration with or without environmental reserve quotas. Our results show that, if rigorously enforced, the Forest Code could prevent a net loss of 53.4 million hectares (Mha) of forest and native vegetation by 2050, 43.1 Mha (81%) of which are in the Amazon alone. The control of illegal deforestation promotes the largest environmental benefits, but the obligatory restoration of illegally deforested areas creates 12.9 Mha of new forested area. Environmental reserve quotas further protect 5.8 Mha of undisturbed natural vegetation. Compared to a scenario without the Forest Code, by 2050, cropland area is only reduced by 4% and the cattle herd by 8%. Our results show that compliance with the Forest Code requires an increase in cattle productivity of 56% over four decades, with a combination of a higher use of supplements and an adoption of semi-intensive pasture management. We estimate that the enforcement of the Forest Code could contribute up to 1.03 PgCO<sub>2</sub>e to the ambitious GHG emissions reduction target set by Brazil for 2030
TOPOGRAFIA DO CONE MEDULAR EM UM GATO MOURISCO, Herpailurus yagouaroundi (Severtzow, 1858)(FELIDAE)
A anestesia caudal foi proposta pela primeira vez em 1926 e diversas técnicas foram
desenvolvidas para anestesiar os nervos espinhais lombares e sacrais. Os métodos para anestesia
epidural exigem conhecimento da anatomia da região envolvida. O objetivo deste estudo foi determinar
a topografia do cone medular do gato mourisco, tornando possível a realização desta técnica
anestésica em um felino silvestre de nossa fauna. Uma gata mourisca, adulta, proveniente do
Zoológico Parque do Sabiá, Uberlândia-MG, foi encaminhado ao Laboratório de Pesquisa em Animais
Silvestres (LAPAS), com o objetivo de determinar a topografia do cone medular para tornar possível
a realização desta técnica anestésica em um felino silvestre de nossa fauna. Este animal foi fixado
em solução de formol a 10%. Feita incisão de pele, os músculos da coluna vertebral foram retirados,
os arcos vertebrais foram seccionados para visualização da medula espinhal e seus envoltórios. O
cone medular neste animal iniciou-se na sexta vértebra lombar (L6) e terminou na segunda vértebra
sacral (S2), com comprimento total de 50mm. O comprimento corporal deste felino foi de 473mm.
Conclui-se que o melhor local para a anestesia epidural do membro pélvico no gato mourisco está
entre as vértebras L6 e S2.
Topographycal study on the medullar cone in jaguarundi, Herpailurus yagouaroundi
(Severtzow,1858)(FELIDAE
Abstract
Since the caudal anesthesia was first proposed in 1926 many techniques were
developed to anesthethize the lumbar and sacral nerves. Such methods for epidural anesthesia
require knowledge of the relative anatomical regions. The objetive of the present study was to determine
the topographic anatomy of the jaguarundi medullar cone as a morphological basis for application of
anesthesis techniques. One adult female jaguarondi that perished by natural death has been obtained
form the Sabiá Zoo Park, Uberlândia, MG, Brazil and conducted to tha Wild Animals Laboratory. The
animal was fixes in 10% formalin solution. Following skin incision, muscles of the vertebral column
were removed and the vertebral arcs sectioned for the visualization of hte spinal cord and its wrappers.
Epidural anesthesic drug in the medullar cone. The medullar cone in this jaguarundi startet in the
sixth lumbar vertebra (L6) and ended in the second sacral vertebra (S2); the spinal cord length was
50mm. The corporal length of this feline measured 473mm. The best region to perform the pelvic
anesthesia in a jaguarundi is between the vertebra L6 and S2
- …