Tuned liquid dampers simulation for earthquake response control of buildings

This paper is focused on the study of an earthquake protection system, the Tuned Liquid Damper (TLD), which can, if adequately designed, reduce earthquake demands on buildings. This positive effect is accomplished taking into account the oscillation of the free surface of a fluid inside a tank (sloshing). The behaviour of an isolated Tuned Liquid Damper, subjected to a sinusoidal excitation at its base, with different displacement amplitudes, was studied by finite element analysis. The efficiency of the TLD in improving the seismic response of an existing building, representative of modern architecture buildings in southern European countries was also evaluated based on linear dynamic analyses

Pathway Weathering in Granitoid Rocks from Central Region of Angola: Geochemical and Mineralogical Data

The Central Region of Angola is characterized by the abundance of granitoid rocks, whose weathering “in situ” originated the so-called residual soils. The textural, geochemical and mineralogical properties of these soils depend not only on the chemical composition of parent rock, but mainly on the local climatic and geomorphological characteristics. In the study area, sampling sites were selected, which extend from the region of Kwanza- Norte (Kassenda, Dondo) through Kwanza-Sul (Cangulo, Quibala and Waco Kungo) until the plateau of Huambo, where samples of fresh rock, weathered rock and its residual soil were collected along each weathering profile. Chemical analytical data were determined using X-ray fluorescence (XRF) analysis of the major and minor elements, whereas mineralogical data were determined using X-ray diffraction (XRD), on the samples of rock and on the respective residual soil. The results obtained and their comparative analysis between the sampling sites, as well as along each weathering profile is presented. This paper allows contributing to the knowledge of the geochemical weathering in tropical areas, as is the case of Angola

Outer retinal layers as predictors of visual acuity in retinitis pigmentosa: a cross-sectional study

PURPOSE: To evaluate the integrity of the outer retinal layers-outer nuclear layer (ONL), external limiting membrane (ELM), ellipsoid (EZ), and interdigitation band (IZ)-using spectral-domain optical coherence tomography and estimate their effect on visual acuity in retinitis pigmentosa (RP). METHODS: A cross-sectional study was performed in the Ophthalmology Department of Hospital de Braga, Portugal. Patients with RP followed in the Hospital de Braga during January to August 2017 were included. Exclusion criteria were lack of data, macular edema due to RP, and concomitant retinal, optic nerve, or corneal disease that could interfere with visual acuity. Age, sex, time from diagnosis, phakic status, ONL thickness, and presence or absence of foveal ELM, EZ, and IZ were correlated to the best-corrected visual acuity (BCVA). RESULTS: Forty-eight eyes were analyzed. There was a strong and positive correlation in BCVA between both eyes (p < .001*). ONL thickness was decreased in 95.8%. The EZ was the most absent layer (79.2%), followed by IZ (70.8%) and ELM (45.8%). A positive family history (p = .04*) and increased time from diagnosis (p = .037*) correlated with worse BCVA. A thicker ONL (p = .001*) and the presence of subfoveal ELM (p < .001*), EZ (p < .001*), and IZ (p = .02*) are correlated with better BCVA. There was a strong and positive correlation between the number of layers affected and a lower BCVA (p < .001). The presence of EZ was a significant predictor of BCVA (p = .02*). CONCLUSIONS: The status of the outer retinal layers seems to influence BCVA. The status of the EZ was the most important predictor of BCVA but the ONL, ELM, and IZ may have a cumulative effect in the progression of visual loss.info:eu-repo/semantics/publishedVersio

Seed abortion in the sexual counterpart of Brachiaria brizantha apomicts (Poaceae).

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Current density distribution mapping in polymer electrolyte membrane fuel cell

A non-uniform utilization of the active area due to inhomogeneous current density distribution is one of the main factors for poor fuel cell performance. Furthermore, it leads to hot points which can be responsible for thermal stress in the membrane electrode assemble (MEA). Therefore, it became extremely important to have a consistent technic to visualize in real time the current density and temperature distribution on the active area. For this purpose a printed circuit board (current scan lin® form S++) was used to measure the current density and temperature distribution. With this equipment it was possible to generate high resolution counters for these two variables. With these results the effect on the current density distribution by different flow fields design, oxygen stoichiometry, and temperature were analysed. Besides, these results can be used to provide crucial data for simulation work, in particular for validation purpose

Chiropractic Manipulation: Reasons for Concern?

Chiropractic's popularity is rising among the general population. Moreover, few studies have been conducted to properly evaluate its safety. We report three cases of serious neurological adverse events in patients treated with chiropractic manipulation. The first case is a 41 years old woman who developed a vertebro-basilar stroke 48 h after cervical manipulation. The second case represents a 68 years old woman who presented a neuropraxic injury of both radial nerves after three sessions of spinal manipulation. The last case is a 34 years old man who developed a cervical epidural haematoma after a chiropractic treatment for neck pain. In all three cases there were criteria to consider a causality relation between the neurological adverse events and the chiropractic manipulation. The described serious adverse events promptly recommend the implementation of a risk alert system

Optical limiting behavior of bismuth oxide-based glass in the visible range

The authors report experimental results on the optical limiting behavior of a bismuth oxide-based glass by exciting the samples with nanosecond laser pulses at 532 and 598 nm. The results show that two-photon and free-carrier absorption processes contribute for the nonlinear absorption. Values for β, the two-photon absorption coefficient, and σe, the absorption cross section due to free carriers, were determined. The values for β and σe are dependent on the amount of bismuth oxide in the glass composition