Wide dynamic range homodyne interferometry method and its application for piezoactuator displacement measurements

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

Pressure distribution on the frontal disk for turbulent flows in a radial diffuser

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

RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

Recently, in [7] we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the alpha'(N) terms of the OSLEEL using open superstring n-point amplitudes in which n is considerably lower than (N + 2) (which is the order of the required amplitude to obtain those alpha'(N) terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger [21], using the pure spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N = 4, 5, 6 and 7). Also, following the spirit of the revisited S-matrix approach, we have found the alpha' expansions for these amplitudes up to alpha'(6) order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).

Doença do disco intervertebral Hansen tipo II em cães: fisiopatologia, abordagem clínico-cirúrgica e controvérsias

Protrusion of the intervertebral disc can cause chronic progressive compression of the spinal cord, and the neurological associated signs vary according to anatomical location, duration and dynamic force of compression. The type II disc disease is not fully understood, and there are many controversies about is clinical significance and best form of treatment. The most important aspect of conservative treatment is rest and physiotherapy associated with mild exercise, and use of corticosteroids to reduce vasogenic edema. The spinal decompression by surgery for removal of disc material from within the medullary canal is the surgical treatment of choice in type I disc disease, but has technical limitations in the type II disc disease. The purpose of this paper is to review the pathophysiology and treatment of chronic intervertebral disc disease and discuss the controversies in medical treatment and the use of some traditional and new surgical techniques.

Utilização da acupuntura no tratamento de cães com discopatia intervertebral

The intervertebral disc diseases have a high casuistic in clinical routines veterinary among dogs. These conditions can cause pain, paresis or paralysis of limbs depending on the degree of injury. Clinical signs are not limited to the intervertebral disc, other anatomical parts are included. In conventional medicine, treatment may be surgical or clinical, by the use of corticosteroids with muscle relaxants. Acupuncture was an alternative to treating these diseases due to its anti-inflammatory and analgesic effects. Although there are few studies for the treatment of discopathies, acupuncture triggers the release of substances such as dynorphins, beta-endorphins and serotonin, among others; that act inhibiting somatic and visceral pain. Electroacupuncture is used to potentiate the effects of acupuncture. It can be performed with different frequencies according to the clinical evolution. However there are different opinions related to the greater efficacy in relation to acupuncture. The restraint and monitoring of the treated animal are important factors for its recovery. The association between acupuncture and conventional treatment (surgical or clinical) achieved better results than acupuncture alone. This proves that acupuncture can be considered an option in order to minimize the complications of surgery or assist in patient recovery

Modelo de conductancia hidráulica de la dentina humana ex vivo

The main objective of this work was to mount and test an experimental model to measure the hydraulic conductance of ex vivo dentin. Seventeen healthy third molars, with indication of extraction of healthy donors aged between 15 and 30 years were obtained by informed consent. After cleaning them, disinfecting them, including them in resin epoxy and cutting them, there were 17 samples of dentin, corresponding to a disk of resin with a coronal section of tooth showing the dentin exposed on both sides of it. Three machines to measure the hydraulic conductance of the dentin were assembled according to the description of the model of Pashley. Samples were installed in a Chamber of diffusion, connected by using silicone tubes to a graduated transfer pipette and a 20cm water column. Through the displacement of a bubble of water in the inside of the pipette, the hydraulic conductance of each sample was measured 3 times on the 14th, 21st, 28th and 35th day post extraction. The data were tabulated and analyzed statistically. There is no SS difference in the rate of flow of a measured sample in the three machines (p=0.5937). There is no SS difference in measurements of the hydraulic conductance of 13 samples of human dentin measured in days 14, 21, 28 and 35 postextraction (p=0.0704). It is possible to mount an experimental model to study the hydraulic conductance of dentin ex vivo, based on the model of Pashley. The model seems to be reliable, but more research is needed in order to validate its reliability.

Geometrical parameter analysis of a high-sensitivity fiber optic angular displacement sensor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nano-displacement measurements of a new piezoelectric flextensional actuator by using a high dynamic range interferometry homodyne method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Magnetic flux quantum in a Superconducting concave/convex disk

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

Behaviour of displacement piles in sand under cyclic axial loading

Field experiments have demonstrated that piles driven into sand can respond to axial cyclic loading in Stable, Unstable or Meta-Stable ways, depending on the combinations of mean and cyclic loads and the number of cycles. An understanding of the three styles of responses is provided by experiments involving a highly instrumented model displacement pile and an array of soil stress sensors installed in fine sand in a pressurised calibration chamber. The different patterns of effective stress developing on and around the shaft are reported, along with the results of static load tests that track the effects on shaft capacity. The interpretation links these observations to the sand's stress strain behaviour. The interface-shear characteristics, the kinematic yielding, the local densification, the growth of a fractured interface-shear zone and the restrained dilatancy at the pile soil interface are all found to be important. The model tests are shown to be compatible with the full-scale behaviour and to provide key information for improving the modelling and the design rules. (C) 2012 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.

THE FIRST DETERMINATION OF THE VISCOSITY PARAMETER IN THE CIRCUMSTELLAR DISK OF A Be STAR

Be stars possess gaseous circumstellar decretion disks, which are well described using standard alpha-disk theory. The Be star 28 CMa recently underwent a long outburst followed by a long period of quiescence, during which the disk dissipated. Here we present the first time-dependent models of the dissipation of a viscous decretion disk. By modeling the rate of decline of the V-band excess, we determine that the viscosity parameter alpha = 1.0 +/- 0.2, corresponding to a mass injection rate (M) over dot = (3.5 +/- 1.3) x 10(-8) M-circle dot yr(-1). Such a large value of a suggests that the origin of the turbulent viscosity is an instability in the disk whose growth is limited by shock dissipation. The mass injection rate is more than an order of magnitude larger than the wind mass-loss rate inferred from UV observations, implying that the mass injection mechanism most likely is not the stellar wind, but some other mechanism.

Alkaline sulfite/anthraquinone pretreatment followed by disk refining of Pinus radiata and Pinus caribaea wood chips for biochemical ethanol production

BACKGROUND: Alkaline sulfite/anthraquinone (ASA) cooking of Pinus radiata and Pinus caribaea wood chips followed by disk refining was used as a pretreatment for the production of low lignified and high fibrillated pulps. The pulps produced with different delignification degrees and refined at different energy inputs (250, 750 and 1600 Wh) were saccharified with cellulases and fermented to ethanol with Saccharomyces cerevisiae using separated hydrolysis and fermentation (SHF) or semi-simultaneous saccharification and fermentation (SSSF) processes. RESULTS: Delignification of ASA pulps was between 25% and 50%, with low glucans losses. Pulp yield was from 70 to 78% for pulps of P. radiata and 60% for the pulp of P. caribaea. Pulps obtained after refining were evaluated in assays of enzymatic hydrolysis. Glucans-to-glucose conversion varied from 20 to 70%, depending on the degree of delignification and fibrillation of the pulps. The best ASA pulp of P. radiata was used in SHF and SSSF experiments of ethanol production. Such experiments produced maximum ethanol concentration of 20 g L-1, which represented roughly90% of glucose conversion and an estimated amount of 260 L ethanol ton(-1) wood. P. caribaea pulp also presented good performance in the enzymatic hydrolysis and fermentation but, due to the low amount of cellulose present, only 140 L ethanol would be obtained from each ton of wood. CONCLUSION: ASA cooking followed by disk refining was shown to be an efficient pretreatment process, which generated a low lignified and high-fibrillated substrate that allowed the production of ethanol from the softwoods with high conversion yields. (C) 2012 Society of Chemical Industry

New activity in the large circumstellar disk of the Be-shell star 48 Librae

Aims. Spectroscopic, polarimetric, and high spectral resolution interferometric data covering the period 1995-2011 are analyzed to document the transition into a new phase of circumstellar disk activity in the classical Be-shell star 48 Lib. The objective is to use this broad data set to additionally test disk oscillations as the basic underlying dynamical process. Methods. The long-term disk evolution is described using the V/R ratio of the violet and red emission components of H alpha and Br gamma, radial velocities and profiles of He I and optical metal shell lines, as well as multi-band BVRI polarimetry. Single-epoch broad-band and high-resolution interferometric visibilities and phases are discussed with respect to a classical disk model and the given baseline orientations. Results. Spectroscopic signatures of disk asymmetries in 48 Lib vanished in the late nineties but recovered some time between 2004 and 2007, as shown by a new large-amplitude and long-duration V/R cycle. Variations in the radial velocity and line profile of conventional shell lines correlate with the V/R behavior. They are shared by narrow absorption cores superimposed on otherwise seemingly photospheric He I lines, which may form in high-density gas at the inner disk close to the photosphere. Large radial velocity variations continued also during the V/R-quiet years, suggesting that V/R may not always be a good indicator of global density waves in the disk. The comparison of the polarization after the recovery of the V/R activity shows a slight increase, while the polarization angle has been constant for more than 20 years, placing tight limits on any 3-D precession or warping of the disk. The broad H-band interferometry gives a disk diameter of (1.72 +/- 0.2) mas (equivalent to 15 stellar radii), position angle of the disk (50 +/- 9)degrees and a relatively low disk flattening of 1.66 +/- 0.3. Within the errors the same disk position angle is derived from polarimetric observations and from photocenter shifts across Br gamma. The high-resolution interferometric visibility and phase profiles show a double or even multiple-component structure. A preliminary estimate based on the size of the Br gamma emitting region indicates a large diameter for the disk (tens of stellar radii). Overall, no serious contradiction between the observations and the disk-oscillation model could be construed.

Planetary nebulae and determination of the bulge-disk boundary

In this paper, a sample of planetary nebulae in the Galaxy's inner-disk and bulge is used to find the galactocentric distance that optimally separates these two populations in terms of their abundances. Statistical distance scales were used to investigate the distribution of abundances across the disk–bulge interface, while a Kolmogorov–Smirnov test was used to find the distance at which the chemical properties of these regions separate optimally. The statistical analysis indicates that, on average, the inner population is characterized by lower abundances than the outer component. Additionally, for the α-element abundances, the inner population does not follow the disk's radial gradient toward the Galactic Center. Based on our results, we suggest a bulge–disk interface at 1.5 kpc, marking the transition between the bulge and the inner disk of the Galaxy as defined by the intermediate-mass population.