The vertical plate in laminar free convection: effects of leading and trailing edges and discontinuous temperature

For laminar free-convection flow past a heated vertical plate of finite length, the local asymptotic flow structure is studied in regions where the boundary-layer equations do not provide a correct approximation at large Grashof numbers. The leading-edge region is shown to contribute a secondorder term to the integrated heat transfer. An integral form of the energy equation permits calculation of this correction in terms of the second-order boundary-layer solution away from the edge, without knowledge of the flow details near the edge, which can be obtained only by solution of the full Navier-Stokes equations. Near the trailing edge and near a jump in the prescribed plate temperature the longitudinal pressure gradient is found to be important in a thin sublayer adjacent to the plate, and the transverse pressure gradient is important in the remainder of the boundary layer, each for a distance along the plate which is slightly larger in order of magnitude than the boundary-layer thickness. At the trailing edge the sublayer problem is nonlinear and cannot be solved analytically, but it can be shown that the local correction to the total heat transfer is of slightly larger order of magnitude than the leading-edge correction. It is pointed out that the trailing-edge flow is identical in form to the flow near the edge of a rotating disc in a stationary fluid. The temperature-jump problem is linear and a solution is given which shows how the singularity in streamline slope predicted by the boundary-layer solution is removed

Effects of waterlogging during grain filling on yield components, nitrogen uptake and grain quality in bread wheat

Waterlogging stress frequently affects wheat production in the current conditions. The aim of this work was to evaluate the effect of waterlogging during grain filling on grain yield components, nitrogen uptake and partitioning and gluten composition and quality in bread wheat. Two greenhouse experiments were conducted under contrasting environmental conditions in Azul, Buenos Aires, in a completely randomized design with three replicates. The cultivar chosen was Klein León and the waterlogging treatment was imposed from 5 days after anthesis to maturity. The effects of waterlogging during grain filling in wheat depended on explored environmental conditions: early sowing vs. late sowing. Waterlogging had not significant effects on the most variables at early sowing conditions. However, the delaying in sowing date (higher temperature and radiation) enhance the effects of waterlogging: i) reducing grain weight by 41% and total nitrogen uptake by 51%; ii) reducing the ratio between the contents of high and low molecular weight glutenin subunits, affecting gluten composition; and iii) increasing the sodium dodecyl sulfate test from 79 to 108 mm, which correlates positively with the gluten strength. Reductions in grain weight due to waterlogging during grain filling affect the milling quality, although changes in protein composition may increase or maintain the gluten strength (SDSS) under particular conditions

Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices

Estudio descriptivo de las cavidades pleurales residuales complicadas tratadas en un Servicio de Cirugía Torácica

Introducción: Las cavidades pleurales residuales se definen como espacios pleurales causados por una falta de reexpansión pulmonar principalmente secundario a infecciones pleurales o cirugías torácicas. Estas pueden cronificarse y complicarse si no logran resolverse con los tratamientos de primera línea (drenaje torácico, fibrinolíticos o decorticación quirúrgica). Material y Métodos: Estudio descriptivo retrospectivo de los pacientes con cavidades pleurales residuales complicadas (CPRC) en el Servicio de Cirugía Torácica del Complejo Hospitalario Universitario de Albacete desde noviembre del 2004 hasta mayo del 2015. Resultados: Sesenta y tres pacientes fueron diagnosticados, con una mayor frecuencia en hombres (n=57; 90,5%). Del total de pacientes intervenidos en este periodo, el 16,27% de cirugías fueron secundarias a esta patología. La patología infecciosa fue la más frecuente (n=35; 55,6%) y dentro de la post-quirúrgica la neumonectomía (n=8; 42,1%), con una media de días desde la intervención quirúrgica hasta el diagnóstico de 190,7 días. En 43 pacientes (68,3%) el cultivo del líquido pleural fue positivo. En 17 pacientes (27%) se asoció a una fístula broncopleural. De los 63 pacientes, 16 (25,4%) recibieron un único tratamiento quirúrgico (25,4%), mientras que 47 (74,6%), precisaron más de un tratamiento. En 39 casos (61,9%) la cavidad pleural complicada se resolvió por medio de los tratamientos, mientras que no lo hizo en 24 (38,1%) pacientes. Conclusiones: A pesar de ser una patología poco frecuente continua presente en la actualidad, principalmente como complicación postquirúrgica o infecciosa. Los tratamientos descritos hasta la fecha no revelan una alta eficacia.Introduction: Residual pleural cavities are pleural spaces caused by a lack of pulmonary reexpansion mainly secondary to pleural infections or thoracic surgeries. If they can not be solved with first line treatments (thoracic drainage, fibrinolytics or surgical decortication), these can become cronic and complicate. Material and Methods: Retrospective descriptive study of patients with complicated residual pleural cavities at the Thoracic Surgery Service of the “Complejo Hospitalario Universitario de Albacete” from November 2004 to May 2015. Results: Sixty-three patients were diagnosed, showing that incidence was more frequent in men (n=57; 90.5%). 16.27% of the surgeries treated within this period were secondary to this pathology. The infectious pathology was the most frequent (n = 35; 55.6%), whereas within the postoperative group, it was pneumonectomy (n = 8; 42.1%), with 190.7 days in average from surgical intervention to the diagnosis. In 43 patients (68.3%), the pleural fluid culture was positive. In 17 patients (27%), it was associated with a bronchopleural fistula. From the 63 patients, 16 (25.4%) received a single surgical treatment (25.4%), while 47 (74.6%) required more than one treatment. In 39 cases (61.9%), the complicated pleural cavity was resolved, whereas in 24 (38.1%) patients it wasn’t. Conclusions: Despite it being a rare pathology, it is still present today, mainly as a post-surgical or infectious complication. To date, the treatments described haven’t exhibited high efficacy

Magnetic dipole probes of the sd and pf shell crossing in the A=36,38 argon isotopes

We have calculated the M1 strength distributions in the A=36,38 argon isotopes within large-scale shell model studies which consider valence nucleons in the sd and pf shells. While the M1 strength in 36Ar is well reproduced within the sd shell, the experimentally observed strong fragmentation of the M1 strength in 38Ar requires configuration mixing between the sd and the pf shells adding to our understanding of correlations across the N=20 shell gap.Comment: 14 pages, 8 figure

Influencia del uso de las tecnologías de internet en el capital estructural

[ESP] Desde la irrupción de Internet, las empresas han emprendido una carrera para posicionarse en el negocio electrónico. Sin embargo, esta inversión se está realizando sin tener una realimentación clara de la rentabilidad que el uso de estas tecnologías les reporta. Este trabajo analiza en que medida el comportamiento de la empresa en Internet se asocia al capital estructural. Para ello, han sido aplicadas técnicas de regresión jerárquica sobre una muestra de 164 empresas del sector de las Telecomunicaciones. Los resultados muestran que la mera presencia en Internet no aporta necesariamente un valor a la empresa, en contraposición a empresas que realmente hacen transacciones en Internet, además se observa que el tamaño se asocia positivamente al capital estructural. [ENG]From the irruption of Internet, companies have undertaken a career for obtaining a position in the electronic business. However, this investment is being accomplishing without having a clear feedback of the profitability that the use of these technologies reports. This work analyzes in which measured the behavior of the company in Internet is associated to the structural capital. In doing so, we have applied hierarchic regression on a sample of 164 companies of the Telecommunications industry. Our results show that the mere presence in Internet does not provide necessarily a value to the company, in contraposition to companies that actually make transactions in Internet, furthermore, it is observed that the size is associated positively to the structural capital

The potential to control Haemonchus contortus in indigenous South African goats with copper oxide wire particles

The high prevalence of resistance of Haemonchus contortus to all major anthelmintic groups has prompted investigations into alternative control methods in South Africa, including the use of copper oxide wire particle (COWP) boluses. To assess the efficacy of COWP against H. contortus in indigenous South African goats, 18 male faecal egg-count-negative goats were each given ca.1200 infective larvae of H. contortus three times per week during weeks 1 and 2 of the experiment. These animals made up an “established” infection group (ESTGRP). At the start of week 7, six goats were each given a 2-g COWP bolus orally; six goats received a 4-g COWP bolus each and six animals were not treated. A further 20 goats constituted a “developing” infection group (DEVGRP). At the beginning of week 1, seven of the DEVGRP goats were given a 2-g COWP bolus each; seven goats were treated with a 4-g COWP bolus each and no bolus was given to a further six animals. During weeks 1–6, each of these DEVGRP goats was given ca. 400 H. contortus larvae three times per week. All 38 goats were euthanized for worm recovery from the abomasa and small intestines in week 11. In the ESTGRP, the 2-g and 4-g COWP boluses reduced the worm burdens by 95% and 93%, respectively compared to controls (mean burden ± standard deviation, SD: 23 ± 33, 30 ± 56 and 442 ± 518 worms, P = 0.02). However, in the DEVGRP goats, both the 2-g and 4-g COWP treatments were ineffective in reducing the worm burdens relative to the controls (mean burdens ± SD: 1102 ± 841, 649 ± 855, 1051 ± 661 worms, P = 0.16). Mean liver copper levels did not differ between the ESTGRP goats treated with 2-g COWP, 4-g COWP or no COWP (mean ± standard error of the mean, SEM, in ppm: 93.7 ± 8.3; 101.5 ± 8.3; 71.8 ± 8.3, P = 0.07) nor did they differ between the DEVGRP goats (mean ± SEM, in ppm: 74.1 ± 9.1; 75.4 ± 9.1; 74.9 ± 10.0, P > 0.99). The copper values were considered adequate, but not high, for goats. The COWP boluses have the potential to be used in the place of conventional anthelmintics for the control of established H. contortus infections in indigenous South African goats, but their use as part of an integrated approach to control H. contortus in the field must be fully investigated

Persistence of the efficacy of copper oxide wire particles against Haemonchus contortus in grazing South African goats

A study was conducted to examine the duration of anthelmintic effect of copper oxide wire particles (COWP) in grazing goats, as data for the persistence of efficacy of COWP in this host species is limited. Forty-eight indigenous male goats were infected naturally by grazing them on Haemonchus contortus-infected pasture. When the faecal egg count (FEC) in the goats was 3179 ± 540 eggs per gram of faeces (mean ± standard error), half the animals were treated with 4 g COWP (day 0; mean live weight = 25.5 ± 0.8 kg). Eight treated (COWP) and eight non-treated (CONTROL) goats were removed from the pasture on each of days 7, 28 and 56, maintained for 27 or 29 days in concrete pens and then humanely slaughtered for nematode recovery. Mean liver copper levels were in the high range in the goats removed from pasture at day 7 (treated: 191 ± 19.7 ppm; untreated: 120 ± 19.7 ppm; P = 0.022), but had dropped to normal levels at days 28 and 56. The mean H. contortus burdens of the treated versus the non-treated goats were, respectively, 184 ± 48 and 645 ± 152 for the goats removed from pasture at day 7 (71% reduction; P = 0.004), 207 ± 42 and 331 ± 156 at day 28 (37% reduction; P = 0.945) and 336 ± 89 and 225 ± 53 at day 56 (−49% reduction; P = 0.665). Weekly monitoring of FECs after treatment until slaughter indicated that the COWP-treated goats had lower FECs than the controls, the treatment main effect being significant at days 7, 28 and 56 (P < 0.01). The day main effect and the treatment × day interaction were only significant for the goats removed from pasture at day 28 (P ≤ 0.001). Packed cell volumes increased during the course of the experiment (day, P < 0.001), but the treatment main effect was significant only for the goats removed from pasture at day 28 (CONTROL 28 d, 28.65 ± 0.52% < COWP 28 d, 31.31 ± 0.52%; P < 0.001). No differences in live weight between groups were considered to be of any practical significance. The study indicated that persistence of efficacy of COWP is limited in goats, extending at most to 28 days after treatment. However, repeated COWP administration at three-month intervals may be safe, given that liver copper levels return to normal two to three months after COWP treatment

Uso de antídotos en un servicio de urgencias pediátricas.

INTRODUCTION: Poisoning is an infrequent cause of consultation in a pediatric emergency department (PED), but it can be potentially serious. Pediatricians should know how to use the available antidotes properly. OBJECTIVES: To analyze the use of antidotes in a PED and to assess the suitability of their indications. MATERIALS AND METHODS: A retrospective review of antidote use in a PED between January 2008 and June 2012. Inclusion criteria were age younger than 18 years and consultation for suspicious poisoning by a substance that could be treated with an antidote. The adequacy of antidote indication was based on the recommendations of the Spanish Society of Pediatric Emergencies (SSPE). RESULTS: A total of 1728 consultations for suspicious poisoning (0.4% of the total visits in the PED) were recorded. In 353 cases (20.4%) the involved poison could be treated with an antidote. Sixty-seven patients received an antidote (3.9% of consultations for suspicious poisoning), and a total of 69 administrations of an antidote were made: 100% oxygen (46), N-acetylcysteine (10), flumazenil (4), naloxone (3), deferoxamine (2), vitamin K (2), bicarbonate (1), and carnitine (1). In 3 cases there was no indication for administration: flumazenil without respiratory depression, and vitamin K following coumarin exposure. As side effects, agitation was noted after the use of flumazenil, and a decrease in the prothrombin time during infusion of N-acetylcysteine. CONCLUSIONS: The administration of antidotes in this PED is uncommon and, mainly, in accordance with the SSPE recommendations, and without serious side effects. The use of flumazenil needs to be limited to the cases with a clear indication and without any contraindication

Geoelectrical and electromagnetic methods applied to paleolimnological studies: Two examples from desiccated lakes in the Basin of Mexico

Paleolimnological studies require a broad understanding of the geometry and depth of the sedimentary fill of lake basins prior to coring campaigns. Seismic methods are routinely employed for the indirect characterization of lake-bottom sediments. However, the use of seismic methods might occasionally be limited due to surface conditions or poor seismic contrasts between the stratigraphic units, which lead to data quality that is too poor to provide sufficient information for the selection of drill sites. Sources of cultural noise are one of the main reasons why seismic methods fail in study areas near or within large cities, such as Mexico City. Under certain conditions, electrical and electromagnetic methods might be a suitable substitute or complement to seismic exploration, as they respond to different physical properties of the subsurface. To evaluate the applicability of such methods, here we present two recent case studies from the desiccated lakes Chalco and Xochimilco both located in urban areas within the Basin of Mexico where electrical resistivity tomography (ERT), transient electromagnetic (TEM) and magnetotelluric (MT) soundings were conducted for the characterization of lake basement and lacustrine sediments. In both examples, the results of the geophysical exploration contributed valuable stratigraphic information for the following drilling and core recovery, which highlights the potential of electrical and electromagnetic methods in paleolimnological studies