Micromechanical analysis of inclusions in particulate media using digital photo stress analysis tomography

An experimental study aimed at sensing the stress distribution characteristics of inclusions inside particulate assemblies subjected to axial compaction is presented here. The particulate assemblies are made of powders and grains in which photo elastic inclusions are embedded along the central axis of the assemblies at different elevations. Digital photo stress analysis tomography is used to obtain the contours of maximum shear stress distribution and the direction of major principal stress within the inclusions under the external loading. Using this, an analysis is performed for understanding the implications of using Hertz theory based discrete element modelling for simulating stresses in relatively big inclusions surrounded by particulates. In the case of the inclusions surrounded by the grains, the location at which peak value in maximum shear stresses occurs within in the inclusions deviates from that of Hertzian analysis. This effect is dominant in the case of inclusions residing close to the loading surface. Unlike granular materials, shear stress distribution characteristics of inclusions in powder surroundings tend to display continuum-like behaviour under external compression and points to the need for a deeper understanding of the effects of surrounding materials in particulate beds with inclusions

Groundwater Quality Assessment in Iworoko-Ekiti Environs, South-Western Nigeria using Chemical Indices: Implications for Irrigation and Household Utilities

Groundwater quality of Iworoko-Ekiti and environs for irrigation and domestic purposes has partly been established using chemical indices. Groundwater quality assessment in the area is of great importance because of the influence of various activities in the area. The area is thickly populated by citizens and higher institution students across Nigeria. At the moment, sanitary conditions are very poor as the main occupations are trading and farming. Nineteen hand-dug wells were randomly sampled within the settlement. Flame photometry and spectrometry were used for cations and anions analyses respectively. Average values of pH, EC and TDS are 7.02, 342µS/cm and 230ppm. The average trend of major cations and anions concentrations is Ca2+>Na+>Mg2+>K+ and HCO3->Cl‑>SO42->CO32- respectively. Average values of Degree of Contamination and Revelle Index are 14 and 0.6 respectively. SAR, MAR, %Na, KI, TH, CIA-1 and CIA-2 has an average value of 0.7, 37.4, 24.8, 0.3, 162ppm, 0.4 and 0.9 respectively. Based on these values, the water is suitable for irrigation. In general, 31.6% of the hand-dug wells are slightly acidic and 10.5% have Revelle index >1 above recommended values respectively. 10.5% from the hand-dug wells have KI above one, 5.3% has MAR above recommendation making them unfit for irrigation purposes. Hence, majority of the wells are suitable for irrigation with exception of a few wells. However, the elevated Cl- concentrations in all the wells, make them unfit for human consumption. Weathering of migmatite and granite gneisses together with anthropogenic activities really contributed to the chemistry of the groundwater

The role of temporary accommodation buildings for post-disaster housing reconstruction

The number of houses damaged or destroyed after disasters is frequently large, and re-housing of homeless people is one of the most important tasks of reconstruction programmes. Reconstruction works often last long and during that time, it is essential to provide victims with the minimum conditions to live with dignity, privacy, and protection. This research intends to demonstrate the crucial role of temporary accommodation buildings to provide spaces where people can live and gradually resume their life until they have a permanent house. The study also aims to identify the main problems of temporary accommodation strategies and to discuss some principles and guidelines in order to reach better design solutions. It is found that temporary accommodation is an issue that goes beyond the simple provision of buildings, since the whole space for temporary settlement is important. Likewise, temporary accommodation is a process that should start before a disaster occurs, as a preventive pre-planning. In spite of being temporary constructions, these housing buildings are one of the most important elements to provide in emergency scenarios, contributing for better recovery and reconstruction actions.The first author gratefully acknowledges the financial support of Fundacao para a Ciencia e a Tecnologia, FCT, through grant SFRH/BD/73853/2010

A new xantphos-type ligand and its gold(I) complexes: Synthesis, structure, luminescence

A novel xantphos analog diphosphine ligand, 9,9-dimethyl-4,5-bis(diphenylphosphinomethyl)-9H-xanthene (X(CP)2), with methylene groups inserted between the xanthene skeleton and the two diphenylphosphine units, has been synthesized. A two-coordinate and a three-coordinate gold(I) complex of the ligand, [Au2Cl2(X(CP)2)] and [AuCl(X(CP)2)], have been prepared and studied by X-ray diffraction, NMR and optical spectroscopy. In the solid state, [AuCl(X(CP)2)] adopts a highly ordered structure with a planar xanthene skeleton that faces another plane composed of two phenyl rings and the AuCl moiety. The structure of [Au2Cl2(X(CP)2)] is much less regular, the two P–Au–Cl vectors point to the opposite sides of the folded xanthene backbone. The exchange-broadened resonances in the NMR spectra of [AuCl(X(CP)2))] indicate that this complex exists as a mixture of various chemical species and/or conformers in solution. In contrast, the NMR spectra of [Au2Cl2(X(CP)2)] exclude any medium-range exchange processes. Aurophilic interactions are absent in both X(CP)2 complexes. X(CP)2, as well as its two gold complexes, is phosphorescent in the solid state; the complexes emit at higher wavelengths and with longer lifetimes than the free ligand

A new source of suprathermal O+ions near the dayside polar cap boundary

A new dayside source of O+ ions for the polar magnetosphere is described, and a statistical survey presented of upward flows of O+ ions using 2 years of data from the retarding ion mass spectrometer (RIMS) experiment on board DE 1, at geocentric distances below 3 RE and invariant latitudes above 40°. The flows are classified according to their spin angle distributions. It is believed that the spacecraft potential near perigee is generally less than +2 V, in which case the entire O+ population at energies below about 60 eV is sampled. Examples are given of field-aligned flow and of transversely accelerated “core” O+ ions; in the latter events a large fraction of the total O+ ion population has been transversely accelerated, and in some extreme cases all the observed ions (of all ion species) have been accelerated, and no residual cold population is observed (“toroidal” distributions). However, by far the most common type of O+ upflow seen by DE RIMS lies near the dayside polar cap boundary (particularly in the prenoon sector) and displays an asymmetric spin angle distribution. In such events the ions carry an upward heat flux, and strong upflow of all species is present (H+, He+, O+, O++, and N+ have all been observed with energies up to about 30 eV, but with the majority of ions below about 2 eV); hence, these have been termed upwelling ion events. The upwelling ions are embedded in larger regions of classical light ion polar wind and are persistently found under the following conditions: at geocentric distances greater than 1.4 RE; at all Kp in summer, but only at high Kp in winter. Low-energy conical ions (<30 eV) are only found near the equatorial edge of the events, the latitude of which moves equatorward with increasing Kp and is highly correlated with the location of field-aligned currents. The RIMS data are fully consistent with a “mass spectrometer effect,” whereby light ions and the more energetic O+ ions flow into the lobes and mantle and hence the far-tail plasma sheet, but lower-energy O+ is swept across the polar cap by the convection electric field, potentially acting as a source for the nightside auroral acceleration regions. The occurrence probability of upwelling ion events, as compared to those of low-altitude transversely accelerated core ions and of field-aligned flow, suggests this could be the dominant mechanism for supplying the nightside auroral acceleration region, and subsequently the ring current and near-earth plasma sheet, with ionospheric O+ ions. It is shown that the total rate of O+ outflow in upwelling ion events (greater than 10^25 s^{−1}) is sufficient for the region near the dayside polar cap boundary to be an important ionospheric heavy ion source

Perioperative, postoperative, and long-term outcomes following open surgical repair of ruptured abdominal aortic aneurysm

We investigated factors that affected perioperative, postoperative, and long-term outcomes of patients who underwent open emergency surgical repair of ruptured abdominal aortic aneurysms (RAAA). All patients who underwent open emergency surgical repair from 1990 to 2011 were included (463 patients; 374 [81%] male; mean age 74.7 ± 8.7years). Logistic and Cox regression analyses were performed to explore the association of variables with outcomes. Preoperatively, median (interquartile range) hemoglobin was 11.2 (9.5-12.8) g/dL, and median creatinine level was 140 (112-177) µmol/L. Intraoperatively, the median operative time was 2.25 (2-3) hours, and median estimated blood loss was 1.5 (0.5-3) L; 250 (54%) patients required intraoperative inotropes, and a median of 6 (4-8) units of blood was transfused. Median length of hospital stay was 11 (7-20) days. In-hospital mortality rate was 35.6%, and 5-year mortality was 48%. Age, distance traveled, operation duration, postoperative myocardial infarction (MI), and multi-organ failure (MOF) were predictors of in-hospital mortality and long-term outcome. Additionally, postoperative acute renal failure predicted in-hospital mortality. In patients with RAAA undergoing open surgical repair, the strongest predictors of in-hospital mortality and long-term outcome were postoperative MOF and MI and operative duration

Syn3DWound: A Synthetic Dataset for 3D Wound Bed Analysis

Wound management poses a significant challenge, particularly for bedridden patients and the elderly. Accurate diagnostic and healing monitoring can significantly benefit from modern image analysis, providing accurate and precise measurements of wounds. Despite several existing techniques, the shortage of expansive and diverse training datasets remains a significant obstacle to constructing machine learning-based frameworks. This paper introduces Syn3DWound, an open-source dataset of high-fidelity simulated wounds with 2D and 3D annotations. We propose baseline methods and a benchmarking framework for automated 3D morphometry analysis and 2D/3D wound segmentation.Comment: In the IEEE International Symposium on Biomedical Imaging (ISBI) 202

Axisymmetric wave propagation in multilayered poroelastic grounds due to a transient acoustic point source

International audienceThis paper deals with the study of axisymmetric wave propagation in various acoustic / porous stratified media coupling configurations. It presents the theoretical development of a semi-analytical method, its validation for a limit test-case half-space ground, and an extension to a realistic multilayered seabed, when spherical waves are emitted from a transient point source in water

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration.

BACKGROUND: It has been proposed that antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. OBJECTIVES: The objective of this review was to assess the effects of antioxidant vitamin or mineral supplementation, or both, on the progression of age-related macular degeneration (AMD). SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2005, Issue 4); MEDLINE (1966 to January 2006); SIGLE (1980 to March 2005); EMBASE (1980 to January 2005); NRR (2005, Issue 4); AMED (1985 to January 2006); and PubMed (24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies. SELECTION CRITERIA: We included randomised trials comparing antioxidant vitamin or mineral supplemention (alone or in combination) to a control intervention in people with AMD. DATA COLLECTION AND ANALYSIS: The author extracted data and assessed trial quality. Where appropriate, data were pooled using a random-effects model unless three or fewer trials were available in which case a fixed-effects model was used. MAIN RESULTS: Eight trials were included in this review. The majority of people were randomised in one trial (AREDS in the USA) that found a beneficial effect of antioxidant (beta-carotene, vitamin C and vitamin E) and zinc supplementation on progression to advanced AMD (adjusted odds ratio 0.68, 99% confidence interval 0.49 to 0.93). People taking supplements were less likely to lose 15 or more letters of visual acuity (adjusted odds ratio 0.77, 99% confidence interval 0.58 to 1.03). Hospitalisation for genito-urinary problems was more common in people taking zinc and yellowing of skin was more common in people taking antioxidants. The other trials were, in general, small and the results were inconsistent. AUTHORS' CONCLUSIONS: The evidence as to the effectiveness of antioxidant vitamin and mineral supplementation in halting the progression of AMD comes mainly from one large trial in the USA. The generalisability of these findings to other populations with different nutritional status is not known. Further large, well-conducted randomised controlled trials in other populations are required. Long-term harm from supplementation cannot be ruled out. Beta-carotene has been found to increase the risk of lung cancer in smokers; vitamin E has been associated with an increased risk of heart failure in people with vascular disease or diabetes

A de novo designed protein-protein interface

As an approach to both explore the physical/chemical parameters that drive molecular self-assembly and to generate novel protein oligomers, we have developed a procedure to generate protein dimers from monomeric proteins using computational protein docking and amino acid sequence design. A fast Fourier transform-based docking algorithm was used to generate a model for a dimeric version of the 56-amino-acid β1 domain of streptococcal protein G. Computational amino acid sequence design of 24 residues at the dimer interface resulted in a heterodimer comprised of 12-fold and eightfold variants of the wild-type protein. The designed proteins were expressed, purified, and characterized using analytical ultracentrifugation and heteronuclear NMR techniques. Although the measured dissociation constant was modest (~300 µM), 2D-[^1H,^(15)N]-HSQC NMR spectra of one of the designed proteins in the absence and presence of its binding partner showed clear evidence of specific dimer formation