1,850 research outputs found
Mollusk freaks: New teratological cases on marine mollusks from the south pacific ocean
Indexación: Scopus.The present study provides new documented cases of abnormalities on chitons (hypomerism and coalescence of shell plates), in addition to four new cases on keyhole limpets (closed apical opening), and one new teratologic case on internal organs in octopuses (missing gill). We assess the frequency of these abnormalities and discuss about its possible environmental, mechanic and genetic causes. Several of these findings represent the first of these cases reported in South Pacific Ocean. © 2018, Escuela de Ciencias del Mar. All rights reserved.http://lajar.ucv.cl/index.php/rlajar/article/view/vol46-issue4-fulltext-
Evaluation of two 99mTc-DTPA radioaerosols with different characteristics in lung ventilation studies
Two radioaerosol preparations, TechneScan®-DTPA (99mTc-DTPA, 40 mCi/3 ml; IPEN-CNEN, São Paulo, SP, Brazil) and TechneScan®-DTPA/AEROSOL (99mTc-DTPA/A, 15 mCi/1.5 ml with 0.5 ml ethanol; Mallinckrodt Medical, St. Louis, MO, USA), were compared in pulmonary ventilation studies in terms of total radiocounts and clearance after inhalation. An aerosol with ethanol is supposed to better distribute the radioparticles in the lungs. Twenty normal nonsmoking volunteers (10 men and 10 women), mean age of 23.2 years (range: 20 to 35 years), were studied. Images were obtained immediately and 30, 60 and 90 min after inhalation. Total and regional counts were obtained and the clearance half-lives of both lungs were determined. There was no difference in total counts between the two types of radioaerosol at any time (mean of ~188,000 cpm for male and female subjects at time zero in both aerosols). The highest count was obtained in the middle region of both lungs (P<0.001) with both preparations. The clearance half-life did not differ between aerosols (mean of ~80-88 min for male and female subjects for both aerosols). Small nonsignificant regional differences were observed. No differences between genders or between right and left lung were observed. 99mTc-DTPA/A generated the highest output of radioaerosol. 99mTc-DTPA with alcohol costs approximately five times more than the aerosol without alcohol. The present results show that either kind of aerosol may be adopted routinely for use in pulmonary examinations without affecting diagnosis. We suggest that the amount of 740 mBq (20 mCi) of 99mTc-DTPA in 1.5 ml saline can be used for routine examinations resulting in reduction of costs in pulmonary ventilation studies without diagnostic impairment.Universidade Federal de São Paulo (UNIFESP) Centro de Reabilitação PulmonarUniversidade Federal de São Paulo (UNIFESP) Departamento de Diagnóstico por ImagemUNIFESP, Centro de Reabilitação PulmonarUNIFESP, Depto. de Diagnóstico por ImagemSciEL
Recovery of different waste vegetable oils for biodiesel production: a pilot experience in Bahia State, Brazil
In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sert\ue3o Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81-85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH.
The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated
Water wave propagation and scattering over topographical bottoms
Here I present a general formulation of water wave propagation and scattering
over topographical bottoms. A simple equation is found and is compared with
existing theories. As an application, the theory is extended to the case of
water waves in a column with many cylindrical steps
Utilisation d'un robot terrestre pour estimer les caracteristiques de la canopee et le rendement au vignoble
This paper aims to present some results of the EU VINBOT (Autonomous cloud-computing vineyard robot to
optimize yield management and wine quality) project focused on vineyard yield estimation. A ground truth
evaluation trial was set up in an experimental vineyard with two plots of the white varieties ‘Alvarinho’ and
‘Arinto’, trained on a vertical shoot positioning system and spur pruned. For each varietal plot, six smart points
were selected with 10 contiguous vines each. During the ripening period of the 2016 season the vines were
manually assessed for canopy dimensions and yield and then scanned by the VINBOT sensor head composed
with a 2D laser rangefinder, a Kinect v2 camera and a set of robot navigation sensors. Ground truth data was
used to compare with the canopy data estimated by the rangefinder and with the output of the image analysis
algorithms. Regarding canopy features (height, volume and exposed leaf area), in general an acceptable fit
between actual and estimated values was observed with canopy height showing the best agreement. The
regression analysis between actual and estimated values of canopy features showed a significant linear
relationship for all the features however the lower values of the R2 indicate a weak relationship. Regarding the
yield, despite the significant R2 (0.31) showed by the regression analysis between actual and estimated values,
the equation of the fitted line indicate that the VINBOT algorithms underestimated the yield by an additive
factor. Our results showed that canopy features can be estimated by the VINBOT platform with an acceptable
accuracy. However, the underestimation of actual yield, caused mainly by bunch occlusion, deserves further
research to improve the algorithms accuracyN/
Semiquantitative theory of electronic Raman scattering from medium-size quantum dots
A consistent semiquantitative theoretical analysis of electronic Raman
scattering from many-electron quantum dots under resonance excitation
conditions has been performed. The theory is based on
random-phase-approximation-like wave functions, with the Coulomb interactions
treated exactly, and hole valence-band mixing accounted for within the
Kohn-Luttinger Hamiltonian framework. The widths of intermediate and final
states in the scattering process, although treated phenomenologically, play a
significant role in the calculations, particularly for well above band gap
excitation. The calculated polarized and unpolarized Raman spectra reveal a
great complexity of features and details when the incident light energy is
swept from below, through, and above the quantum dot band gap. Incoming and
outgoing resonances dramatically modify the Raman intensities of the single
particle, charge density, and spin density excitations. The theoretical results
are presented in detail and discussed with regard to experimental observations.Comment: Submitted to Phys. Rev.
Diffusive and localization behavior of electromagnetic waves in a two-dimensional random medium
In this paper, we discuss the transport phenomena of electromagnetic waves in
a two-dimensional random system which is composed of arrays of electrical
dipoles, following the model presented earlier by Erdogan, et al. (J. Opt. Soc.
Am. B {\bf 10}, 391 (1993)). A set of self-consistent equations is presented,
accounting for the multiple scattering in the system, and is then solved
numerically. A strong localization regime is discovered in the frequency
domain. The transport properties within, near the edge of and nearly outside
the localization regime are investigated for different parameters such as
filling factor and system size. The results show that within the localization
regime, waves are trapped near the transmitting source. Meanwhile, the
diffusive waves follow an intuitive but expected picture. That is, they
increase with travelling path as more and more random scattering incurs,
followed by a saturation, then start to decay exponentially when the travelling
path is large enough, signifying the localization effect. For the cases that
the frequencies are near the boundary of or outside the localization regime,
the results of diffusive waves are compared with the diffusion approximation,
showing less encouraging agreement as in other systems (Asatryan, et al., Phys.
Rev. E {\bf 67}, 036605 (2003).)Comment: 8 pages 9 figure
Equation of State of Oscillating Brans-Dicke Scalar and Extra Dimensions
We consider a Brans-Dicke scalar field stabilized by a general power law
potential with power index at a finite equilibrium value. Redshifting
matter induces oscillations of the scalar field around its equilibrium due to
the scalar field coupling to the trace of the energy momentum tensor. If the
stabilizing potential is sufficiently steep these high frequency oscillations
are consistent with observational and experimental constraints for arbitrary
value of the Brans-Dicke parameter . We study analytically and
numerically the equation of state of these high frequency oscillations in terms
of the parameters and and find the corresponding evolution of the
universe scale factor. We find that the equation of state parameter can be
negative and less than -1 but it is not related to the evolution of the scale
factor in the usual way. Nevertheless, accelerating expansion is found for a
certain parameter range. Our analysis applies also to oscillations of the size
of extra dimensions (the radion field) around an equilibrium value. This
duality between self-coupled Brans-Dicke and radion dynamics is applicable for
where D is the number of extra dimensions.Comment: 10 two-column pages, RevTex4, 8 figures. Added clarifying
discussions, new references. Accepted in Phys. Rev. D (to appear
Airborne olive pollen counts are not representative of exposure to the major olive allergen Ole e 1
Pollen is routinely monitored, but it is unknown whether pollen counts represent
allergen exposure. We therefore simultaneously determined olive pollen and Ole e
1 in ambient air in C ordoba, Spain, and Evora, Portugal, using Hirst-type traps
for pollen and high-volume cascade impactors for allergen.
Pollen from different days released 12-fold different amounts of Ole e 1 per
pollen (both locations P < 0.001). Average allergen release from pollen (pollen
potency) was much higher in C ordoba (3.9 pg Ole e 1/pollen) than in Evora
(0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in C ordoba
were 2.4 times higher than in Evora, but Ole e 1 concentrations were 7.6 times
higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in
Evora was explained by high-potency pollen originating from the south of Spain.
Thus, olive pollen can vary substantially in allergen release, even though they are
morphologically identical
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