The effect of pre-strain on fatigue for a high strength low alloy (HSLA) steel

The effect of initial plastic strain cycle fatigue lives of HSLA specimens is investigated. Specimens were monotonically, quasi-statically loaded under strain control in tension to produce plastic strains (prestrain conditions s0 = 0, s1 = 4,6, s2 = 35,6 and s3 = 66,7 % deformation). Surface analysis on the annealed Zn coat on the prestrain surfaces shows that, the higher the deformation the bigger and deeper the cracks on the Zn coat. Results show that the higher prestrain the higher fatigue resistance for all stress applied, specimens with s3 shows the highest fatigue resistance for these experimental conditions

Ensayos de bioestimulación algal con diferentes relaciones nitrógeno: fósforo bajo condiciones de laboratorio

Esta investigación tuvo como objetivo evaluar el crecimiento del alga Chlorella vulgaris ante diferentes concentraciones de nitrógeno y fósforo, a través de ensayos de bioestimulación en una cámara ambiental. Las variables respuesta fueron la densidad algal y la turbidez, evaluadas por conteo en una cámara de Neubauer y por espectrofotometría, empleando un equipo NOVA 60.Para los ensayos de bioestimulación se utilizó el medio de cultivo Estándar Métodos, sugerido por APHA, AWWA (1995) con diferentes concentraciones de nitrógeno y de fósforo. En general, se concluyó que la bioestimulación del crecimiento de Chlorella vulgaris depende de la relación estequiométrica entre el nitrógeno y el fósforo. En síntesis, cuando el fósforo se hace menos limitante se presentó una mayor tasa de crecimiento poblacional. Sin embargo, el nitrógeno es también esencial y ambos nutrientes no pueden ser analizados independientemente. Por lo tanto, el aumento o la disminución de las concentraciones de estos nutrientes en los ambientes acuáticos deben ser estudiados conjuntamente a través de sus relaciones estequiométricas

Estilo de vida y estado de nutrición en niños escolares

ResumenObjetivoRelacionar el estilo de vida y el estado de nutrición en escolares.MétodoEstudio correlacional, participaron 260 niños adscritos a la Clínica ISSSTE, elegidos aleatoriamente. Se utilizó el cuestionario sobre estilos de vida en la niñez y se valoró el peso y talla. Se obtuvo la aprobación de la Jefatura de Investigación del ISSSTE. En el análisis de datos se aplicó estadística descriptiva e inferencial.ResultadosParticiparon 137 niños y 123 niñas, con edades entre 6-12 años. Respecto al estado de nutrición, 5 de cada 10 de los participantes se encuentran en peso normal, 2 de cada 10 en sobrepeso y uno de cada 10 en obesidad y peso bajo. Sobre el estilo de vida 7 de cada 10 de los participantes se encontraron en riesgo bajo y 2 de cada 10 en riesgo mediano. Por otra parte, no se encontró relación entre el estilo de vida de los niños y su estado de nutrición (rs=0.038, p>0.05). Adicionalmente, se encontró que los niños con peso normal o bajo peso tienen mejores hábitos de sueño que los niños con sobrepeso u obesidad (U=3.79, p<0.001).ConclusionesEste estudio muestra indicios de que los aspectos vinculados con la dimensión psicocorporal y con uso del tiempo libre deberían indagarse a mayor profundidad, ya que fueron los que arrojaron cifras que ubican a los escolares en riesgo medio y alto.AbstractObjectiveTo explore the association between lifestyle and nutritional status among school children.MethodCorrelational study involving 260 children registered at an ISSSTE clinic, who were randomly selected. A questionnaire on childhood lifestyles was used; weight and height were also assessed. A project approval from the ISSSTE research committee was obtained. Descriptive and inferential statistics were used.Results137 boys and 123 girls with ages between 6 and 12 years old participated. In relation to the nutrition status, five out every ten have a normal weight; two out every ten are over weighted, and one out of every ten is obese or under weighted respectively. In relation to lifestyle, seven out of every ten participants have low risk; and two out of every ten have medium risk. On the other hand a relation between the lifestyle and nutritional status of the children was not found (rs=.038, p>0.05). Moreover, it was found that children with normal or low weights have better sleep habits in comparison to the children who are over weighted or obese U=3.79, p <.001).ConclusionsThis study suggests that issues related to the psychological and corporal dimensions, as well as the use of free time, should be further explored because they showed figures which place children within mid and high risks

Compensation of inorganic acid interferences in ICP-OES and ICP-MS using a Flow Blurring® multinebulizer

A new and easy method has been proposed for compensation of inorganic acid matrix effects in ICP-OES and ICP-MS. The method consists on an on-line standard addition calibration using a Flow Blurring® multinebulizer (FBMN-based system). Experimental conditions of the FBMN-based system are optimized for both ICP-OES and ICP-MS. Under optimized conditions recovery values obtained in the analysis of synthetic acid samples were close to 100% for HNO3 and HCl (with acid concentrations of up to 15% (w w-1)) and H2SO4 (up to 10% (w w-1)) for both plasma-based spectrochemical techniques. The applicability of the proposed method has been evaluated analyzing two whole milk powders, certified reference material and a commercial product, showing excellent recovery values. Compared with other calibration strategies and experimental setups used, the on-line standard addition calibration using the FBMN-based system is faster, easier to handle and significantly reduces reagents and sample consumption.The authors express their gratitude to the Spanish Ministry of Science and Innovation (projects n. CTQ2008 06730-C02-01 and PHB-2010-0018-PC), to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior in Brazil (Grant CAPES-DGU 243/11), and the Regional Government of Valencia (Spain) (projects n. ACOMP/2009/144 and ACOMP/2010/047) for financial support. The authors gratefully acknowledge OneNeb® (Division of Ingeniatrics Tecnologías S.L.) for the FBMN prototype provided. M.A.A. thanks the University of Alicante for his PhD fellowship. This work is part of the Ph.D. degree of M.A.A

Aerosol generation of As and Se hydrides using a new Flow Blurring® multiple nebulizer for sample introduction in inductively coupled plasma optical emission spectrometry

A new Flow Blurring® multiple nebulizer (FBMN) has been used for the efficient generation of As and Se hydrides directly into the aerosol formed inside the spray chamber before detection by inductively coupled plasma optical emission spectrometry (ICP OES). The FBMN allowed the hydride generation directly into the spray chamber without using any additional device either for solution and gas control or for gas phase separation. Synthetic solutions containing As and Se plus Ca, Mg and K were used for evaluating matrix effects and Ge was suggested as internal standard. Limits of detection of 2.7 and 5.8 μg L− 1 were obtained for As and Se, respectively, when keeping the nebulization gas flow rate at 0.60 L min− 1 and the liquid flow rate at 0.67 mL min− 1. The developed procedure was applied for spiked digests of food samples and quantitative recoveries were attained. The combination of FBMN, internal standard and hydride generation is a robust and simple approach for generating As and Se hydrides directly into the aerosol.The authors express their gratitude to the Spanish Government (Grant CTQ2008-06730-C02-01, CTQ2011-23968 and PHB-2010-0018-PC) and to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior in Brazil (Grant CAPES-DGU 243/11) for financial support

Integrating Deep-Web Information Sources

Deep-web information sources are difficult to integrate into automated business processes if they only provide a search form. A wrapping agent is a piece of software that allows a developer to query such information sources without worrying about the details of interacting with such forms. Our goal is to help soft ware engineers construct wrapping agents that interpret queries written in high-level structured languages. We think that this shall definitely help reduce integration costs because this shall relieve developers from the burden of transforming their queries into low-level interactions in an ad-hoc manner. In this paper, we report on our reference framework, delve into the related work, and highlight current research challenges. This is intended to help guide future research efforts in this area.Ministerio de Educación y Ciencia TIN2007-64119Junta de Andalucía P07-TIC-2602Junta de Andalucía P08-TIC-4100Ministerio de Ciencia e Innovación TIN2008-04718-

Estudio descriptivo retrospectivo de la fractura de cadera en un área de salud de la Comunidad Valenciana

Se presenta un estudio descriptivo de la fractura de cadera osteoporótica en el área de Salud 20 de la Comunidad Valenciana durante el año 2007. Se incluyó una serie consecutiva de 239 pacientes que sufrieron fractura de fémur proximal. Se diseñó una base de datos recogiendo información clínica como la edad, sexo, tipo de fractura y lateralidad, antecedentes personales, datos referidos al accidente, al ingreso y estancia, así como al tratamiento.A descriptive study of osteoporotic hip fracture in the Health area 20 of the Valencian Community in 2007. We included a consecutive series of 239 patients undergoing proximal femoral fracture. We created a database collecting clinical information such as age, sex, type of fracture and handedness, personal history, referred to the accident data, entry and stay, and treatment

Analysis of waste electrical and electronic equipment (WEEE) using laser induced breakdown spectroscopy (LIBS) and multivariate analysis

This study shows the application of laser induced breakdown spectroscopy (LIBS) for waste electrical and electronic equipment (WEEE) investigation. Several emission spectra were obtained for 7 different mobiles from 4 different manufacturers. Using the emission spectra of the black components it was possible to see some differences among the manufacturers and some emission lines from organic elements and molecules (N, O, CN and C2) led to the highest contribution for this differentiation. Some polymeric internal parts in contact with the inner pieces of the mobiles and covered with a special paint presented a strong emission signal for Cr. The white pieces presented mainly Al, Ba and Ti in their composition. Finally, this study developed a procedure for LIBS emission spectra using chemometric strategies and suitable information can be obtained for identification of manufacturer and counterfeit products. In addition, the results obtained can improve the classification for establishing recycling strategies of e-waste.The authors are grateful to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES- DGU, Grant 243/11), to the Spanish Government (Projects CTQ2008-06730-C02-01, CTQ2011-23968 and PHB2010-0018-PC), to Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq (grants 304772/2012-7 and 474357/2012-0), and to Grant 2012/01769-3, São Paulo Research Foundation (FAPESP) for the financial support