Extreme pressure behaviour of newly formulated oil-in-water emulsions

Oil-in-water (O/W) emulsions are broadly used in metal-machining processes, where combined lubrication and refrigeration are needed, such as in cutting, rolling, or grinding. These fluids consist of tiny oil droplets in water stabilised by small amounts of emulsifiers, namely surfactants. In an emulsion, oil is responsible for the lubricating properties, whereas water provides heat dissipation and fire resistance. Normally, emulsifiable metalworking oils are used in an oil concentration between 2 and 5 vol. %, depending on the application. Despite their wide use, the lubrication mechanisms of o/w emulsions have not been fully understood, mainly because of their complexity. Previous studies on oil-in-water emulsions showed that, in order to form thick lubricant films, oil droplets must wet the metal surfaces, displacing water. The ability of oil to wet is strongly dependent on the concentration of surfactant. Surfactant molecules tend to adsorb preferentially at the interface, modifying the nature of the layers adjacent to the metal surfaces and, thus, playing a key role in processes such as wettability, corrosion, or friction, as well as emulsion stability. The aim of this work is to study the influence of concentration of two different emulsifiers (anionic and non-inonic) on the wettability and extreme pressure properties of an oil-in-water emulsion. A mixture of a synthetic polyalphaolefin and a trimethylol propane ester was used as the base oil, and the concentrations of emulsifiers were below, equal to, and above their critical micellar concentrations (CMC). Extreme pressure tests (ASTM D 2783), which try to simulate the operating conditions of high speeds and pressures taking place in cutting processes, and contact angle measurements were carried out in order to establish a relationship between both properties and to evaluate the performance of these emulsions as lubricants

Resolving galaxies in time and space: II: Uncertainties in the spectral synthesis of datacubes

In a companion paper we have presented many products derived from the application of the spectral synthesis code STARLIGHT to datacubes from the CALIFA survey, including 2D maps of stellar population properties and 1D averages in the temporal and spatial dimensions. Here we evaluate the uncertainties in these products. Uncertainties due to noise and spectral shape calibration errors and to the synthesis method are investigated by means of a suite of simulations based on 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models. We compare results obtained with the Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 100k CALIFA spectra are used in this comparison. Noise and shape-related errors at the level expected for CALIFA propagate to 0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities. Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16 mag for shape errors. Higher order products such as SFHs are more uncertain, but still relatively stable. Due to the large number statistics of datacubes, spatial averaging reduces uncertainties while preserving information on the history and structure of stellar populations. Radial profiles of global properties, as well as SFHs averaged over different regions are much more stable than for individual spaxels. Uncertainties related to the choice of base models are larger than those associated with data and method. Differences in mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V. Spectral residuals are ~ 1% on average, but with systematic features of up to 4%. The origin of these features is discussed. (Abridged)Comment: A&A, accepte

Sistemas de acceso venoso central (SAVC) en pacientes pediátricos. Experiencia de seis años

The need for an access to the venous system, in order to infuse chemotherapeutic treatments or parenteral nutrition, has increased the number of central venous access systems (CVAS) implanted in the past years. Between February 1985 and December 1990, 87 devices were implanted in 76 patients (from 11 months to 15 years of age), with a median function time of 349 days (range: 7 to 1887 days). The overall incidence of complications was 0.10 per 10 days of catheterization, with complication rates for infection and thrombosis of 0.02 and 0.03, respectively. Nineteen systems were removed because of complications and 11 because of completion of the treatment. Of the cases, 97.7% included a follow-up period. The present study confirms the advantages of these devices, with a long working life and a low complication rate, being a good alternative for chronically ill children requiring long-term and/or cyclic intravenous therapy

Short-term oral administration of non-porous and mesoporous silica did not induce local or systemic toxicity in mice

In this study, two sets of methyl-coated non-porous and mesoporous amorphous silica materials of two target sizes (100 and 300 nm; 10–844 m2/g) were used to investigate the potential role of specific surface area (SSA) and porosity on the oral toxicity in mice. Female Swiss mice were administered by oral gavage for 5 consecutive days. Two silica dose levels (100 and 1000 mg/kg b.w.) were tested for all four materials. All dispersions were characterized by transmission electron microscopy (TEM) and Nanoparticle tracking analysis (NTA). Batch dispersions of porous silica were rather unstable due to agglomeration. Animals were sacrificed one day after the last administration or after a three-week recovery period. No relevant toxicological effects were induced by any of the silica materials tested, as evaluated by body weight, gross pathology, relative organ weights (liver, spleen, kidneys), hematology, blood biochemistry, genotoxicity (Comet assay in jejunum cells and micronucleus test in peripheral blood erythrocytes), liver and small intestine histopathology, and intestinal inflammation. The presence of silica particles in the intestine was evaluated by a hyperspectral imaging microscopy system (CytoViva) using histological samples of jejunum tissue. Silica spectral signatures were found in jejunum samples with all the treatments, but only statistically significant in one of the treatment groups

JPCam: A 1.2Gpixel camera for the J-PAS survey

JPCam is a 14-CCD mosaic camera, using the new e2v 9k-by-9k 10microm-pixel 16-channel detectors, to be deployed on a dedicated 2.55m wide-field telescope at the OAJ (Observatorio Astrofisico de Javalambre) in Aragon, Spain. The camera is designed to perform a Baryon Acoustic Oscillations (BAO) survey of the northern sky. The J-PAS survey strategy will use 54 relatively narrow-band (~13.8nm) filters equi-spaced between 370 and 920nm plus 3 broad-band filters to achieve unprecedented photometric red-shift accuracies for faint galaxies over ~8000 square degrees of sky. The cryostat, detector mosaic and read electronics is being supplied by e2v under contract to J-PAS while the mechanical structure, housing the shutter and filter assembly, is being designed and constructed by a Brazilian consortium led by INPE (Instituto Nacional de Pesquisas Espaciais). Four sets of 14 filters are placed in the ambient environment, just above the dewar window but directly in line with the detectors, leading to a mosaic having ~10mm gaps between each CCD. The massive 500mm aperture shutter is expected to be supplied by the Argelander-Institut fur Astronomie, Bonn. We will present an overview of JPCam, from the filter configuration through to the CCD mosaic camera. A brief outline of the main J-PAS science projects will be included.Comment: 11 pages and 9 figure

Loop Quantum Gravity and the The Planck Regime of Cosmology

The very early universe provides the best arena we currently have to test quantum gravity theories. The success of the inflationary paradigm in accounting for the observed inhomogeneities in the cosmic microwave background already illustrates this point to a certain extent because the paradigm is based on quantum field theory on the curved cosmological space-times. However, this analysis excludes the Planck era because the background space-time satisfies Einstein's equations all the way back to the big bang singularity. Using techniques from loop quantum gravity, the paradigm has now been extended to a self-consistent theory from the Planck regime to the onset of inflation, covering some 11 orders of magnitude in curvature. In addition, for a narrow window of initial conditions, there are departures from the standard paradigm, with novel effects, such as a modification of the consistency relation involving the scalar and tensor power spectra and a new source for non-Gaussianities. Thus, the genesis of the large scale structure of the universe can be traced back to quantum gravity fluctuations \emph{in the Planck regime}. This report provides a bird's eye view of these developments for the general relativity community.Comment: 23 pages, 4 figures. Plenary talk at the Conference: Relativity and Gravitation: 100 Years after Einstein in Prague. To appear in the Proceedings to be published by Edition Open Access. Summarizes results that appeared in journal articles [2-13

Association between Parkinson's disease and diabetes: Data from NEDICES study

Background: Despite growing evidence showing an association between Parkinson's disease (PD) and diabetes, epidemiological studies have shown conflicting results. Aims of the study: To evaluate the association between PD and diabetes and the impact of diabetes duration in this association in an elderly (≥65 years) Spanish population. Methods: Data for this cross-sectional population-based analysis were obtained from NEDICES study. Subjects were identified from census list. Diagnosis of PD was confirmed by neurological examination. Diabetes was defined by self-report, being on antidiabetic medication or diagnosis on medical records. Logistic regression analysis adjusted by potential confounders was performed to estimate the association between both conditions and also after dividing patients into short-duration (<10 years) and long-duration (≥10 years) diabetes. Results: A total of 4998 subjects were included (79 PD and 4919 controls). Univariate analysis did not show any association between prevalence of PD and diabetes (OR 1.89, 95% CI 0.90-3.98, P=.09), although subgroup analysis showed a positive association in those with long-duration diabetes (3.27, 95% CI 1.21-8.85, P=.02). Conclusions: Diabetes duration might be an important factor in the association between PD and diabetes, and the risk might be limited to those with longer disease duration

Obtaining of repair lime mortars by mixing aerial lime and nanosilica

This work deals with the effect of the nanosilica addition on the performance of aerial lime mortars. Several lime mortars were prepared and modified upon the addition of 3, 6, 10 and 20 wt.% of nanosilica. The presence of nanosilica increased the water demand of the fresh mixtures and reduced the appearance of superficial cracks after the spreading of the mortars onto a porous stone. Setting time underwent a delay when the amount of nanosilica ranged from 3 to 10 wt.%. However, samples with 20 wt.% of nanosilica showed a shortened setting time compared to plain lime mortars. Nanosilica reacted with Ca(OH)2 particles, yielding C-S-H compounds and, acting as a nanofiller, nanosilica also caused a pore blockage in the mesoporous range. These facts resulted in an increase in both compressive strength and durability after undergoing freezing-thawing processes. Overall, the addition of nanosilica clearly improves several characteristics of the aerial lime mortars in order to prepare enhanced mixtures to be used for restoration works

Observation of a New Excited Ds+ Meson in B0 →d-D+K+π-Decays

Using pp collision data corresponding to an integrated luminosity of 5.4 fb−1 collected with the LHCb detector at a center-of-mass energy of 13 TeV, the B0 → D−DþKþπ− decay is studied. A new excited Dþ s meson is observed decaying into the DþKþπ− final state with large statistical significance. The pole mass and width, and the spin parity of the new state are measured with an amplitude analysis to be mR ¼ 2591 6 7 MeV, ΓR ¼ 89 16 12 MeV, and JP ¼ 0−, where the first uncertainty is statistical and the second systematic. Fit fractions for all components in the amplitude analysis are also reported. The new resonance, denoted as Ds0ð2590Þþ, is a strong candidate to be the Dsð21 S0Þþ state, the radial excitation of the pseudoscalar ground-state Dþ s meson

Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review

Background: Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture. Methods: We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age. Results: The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful. Conclusion: Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation