2,552 research outputs found

    Analysis of Ostwald ripening in Ni-rich Ni–Ti alloys by diffusion couples

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    "The coarsening kinetics of gamma' precipitates in Ni-rich Ni-Ti alloys are studied using a Ni-11-5 wt% Ti and pure Ni diffusion couple. The formed concentration gradient allowed to study the aging process at 1023 K (750 degrees C) in Ni-rich Ni Ti alloys with Ti content from 8-62 to 11-15 wt% Ti. In general, during the coarsening of gamma' precipitates, the experimental coarsening kinetics do not fit well to the LSW or TIDC theoretical models and anomalous behaviour of coarsening rate constant (k(r)) associated with gamma' volume-fraction is confirmed at high values.

    Modulated-laser source induction system for remote detection of infrared emissions of high explosives using laser-induced thermal emission

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    In a homeland security setting, the ability to detect explosives at a distance is a top security priority. Consequently, the development of remote, noncontact detection systems continues to represent a path forward. In this vein, a remote detection system for excitation of infrared emissions using a CO2 laser for generating laser-induced thermal emission (LITE) is a possible solution. However, a LITE system using a CO2 laser has certain limitations, such as the requirement of careful alignment, interference by the CO2 signal during detection, and the power density loss due to the increase of the laser image at the sample plane with the detection distance. A remote chopped-laser induction system for LITE detection using a CO2 laser source coupled to a focusing telescope was built to solve some of these limitations. Samples of fixed surface concentration (500 μg∕cm2) of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) were used for the remote detection experiments at distances ranging between 4 and 8 m. This system was capable of thermally exciting and capturing the thermal emissions (TEs) at different times in a cyclic manner by a Fourier transform infrared (FTIR) spectrometer coupled to a gold-coated reflection optics telescope (FTIR-GT). This was done using a wheel blocking the capture of TE by the FTIR-GT chopper while heating the sample with the CO2 laser. As the wheel moved, it blocked the CO2 laser and allowed the spectroscopic system to capture the TEs of RDX. Different periods (or frequencies) of wheel spin and FTIR-GT integration times were evaluated to find dependence with observation distance of the maximum intensity detection, minimum signal-to-noise ratio, CO2 laser spot size increase, and the induced temperature incremen

    Calidad de vida y función sexual en mujeres con disfunción del piso-pélvico del sur de Chile

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    Antecedentes/Objetivos: La disfunción del piso pélvico (DPP) es muy prevalente, afectando a un tercio de las mujeres adultas. Estas patologías no suponen un riesgo vital, pero sus síntomas pueden interferir con las actividades de la vida diaria incluyendo aspectos físicos, sociales y sexuales. En el sur de Chile, en el Hospital de alta complejidad (Regional-Concepción), se ha implementado la Unidad de Piso Pélvico (UPP). No hay evidencia sobre el efecto que supone en la calidad de vida y la función sexual de las mujeres que la padecen Describir la calidad de vida y función sexual de mujeres controladas en la Unidad de Piso Pélvico de un Hospital de alta complejidad en Chile. Métodos: Estudio transversal. Población: usuarias con DPP de la UPP del H. Regional-Concepción. Muestra 173. Variables: Caract. sociodemográficas, antecedentes obstétricos, tipo de DPP, Variables de Calidad de Vida (percepción del estado de salud, limitación emocional, limitación de actividades cotidianas, alteraciones de actividades sociales) (Short Form-12 Health Survey) y función sexual (PISQ-12). Análisis: medidas de dispersión, frecuencia absoluta- relativa. Resultados: Edad media 57 años, 88% con ingreso menor a 357€. 91% con IMC-sobrepeso y obesidad, 64% ≥ 3 hijos. Tipos DPP: 53% incontinencia de orina (IO), 35% prolapso vaginal (Pp), 12% IO+Pp. Calidad de vida (n = 173): Mala percepción de salud: 95%. Limitación emocional: 37%. Limitación de actividades cotidianas: 67%. Alteraciones de actividades sociales: 57% Función sexual (n = 95): Disfunción alta: 8,4%, moderada: 41,1%, baja 50,5%. El 15% nunca tuvo deseo-sexual los últimos 6 meses. El 14% admite no haber alcanzado el orgasmo en los últimos 6 meses, el mismo porcentaje admite no sentir excitación en el mismo período. El 19% admite no estar satisfechas con las actividades sexuales actuales, el 15% siente dolor durante las relaciones sexuales, el 40% admite sufrir de pérdidas de orina durante la actividad sexual, y el mismo número admite restringir su vida sexual debido al miedo de pérdida de orina durante el acto sexual. El 27% admite tener reacciones emocionales negativas durante las relaciones sexuales. El 10% y el 13% admite que sus parejas sufrían de disfunción eréctil y eyaculación, respectivamente. Por último, el 42% de las mujeres admite que sus orgasmos en los últimos 6 meses son más intensos. Conclusiones: Las mujeres con DPP presentan una alteración negativa de su calidad de vida y de su función sexual, aunque existe cierta incongruencia al valorar positivamente la calidad de los orgasmos cuando los demás aspectos de la vida sexual son negativos

    Analysis of the Relationship between Lifestyle and Coffee Consumption Habits, from the Myth Approach, in the Municipalities of Orizaba, Tehuipango, and Zongolica Veracruz.

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    Coffee consumption habits have evolved along with society for more than 300 years around the world. Social changes imply different lifestyles in each culture. Lifestyles influence the myths used by people in their consumption decisions. The objective of this research is to determine the relationship between lifestyle and coffee consumption habits, from the perspective of myth, in the inhabitants of the Mexican municipalities of Orizaba, Tehuipango, and Zongolica. A survey was conducted with a sample of inhabitants of the three municipalities studied. The statistical analyzes applied were the central limit theorem, Pearson, and Chi-square. The results show that the variables Consumption habits-Lifestyle-Myth, are highly dependent on the level of perception of people. It is concluded that the coffee myth corresponds to the "family union" in the study municipalities. This myth is not characterized in the evolutionary stages contemplated in the "waves of coffee"

    Calidad del agua del estero el sauce, valparaíso, chile central water quality in the el sauce estuary, valparaíso, central Chile

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    Indexación: Scopus.The main objective of this work was to evaluate the water quality of the El Sauce estuary and its tributaries. The El Sauce estuary basin is located in the town of Laguna Verde, Valparaíso, Central Chile. Sampling took place in the summer season of 2013 and 2015, in 11 stations located along the basin, five of them distributed from its origin to its mouth in the sea and six located before entering its tributaries. Point and non-point sources downloaded in its course were identified. The direct discharge of water from a sewage treatment plant in the area of origin of the estuary, and in its middle zone the percolation of a municipal landfill, stand out for their volume. Its mouth is affected by non-point sources of domestic waters in the town of Laguna Verde. The results show that the estuary is a shallow water course, which quality Class 4 (poor) in most of its extension presents due to the content of organic matter, nutrients, chlorides, and fecal contamination, not complying with environmental regulations for any use. There is a lack of management and control plans in the use of this important resource. It has become a risk to the community, who use the water of the stream both to irrigate subsistence agriculture and for recreation with a direct contact at its mouth.https://www.revistascca.unam.mx/rica/index.php/rica/article/view/RICA.534

    Artificial intelligence assisted Mid-infrared laser spectroscopy in situ detection of petroleum in soils

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    A simple, remote-sensed method of detection of traces of petroleum in soil combining artificial intelligence (AI) with mid-infrared (MIR) laser spectroscopy is presented. A portable MIR quantum cascade laser (QCL) was used as an excitation source, making the technique amenable to field applications. The MIR spectral region is more informative and useful than the near IR region for the detection of pollutants in soil. Remote sensing, coupled with a support vector machine (SVM) algorithm, was used to accurately identify the presence/absence of traces of petroleum in soil mixtures. Chemometrics tools such as principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA), and SVM demonstrated the e ectiveness of rapidly di erentiating between di erent soil types and detecting the presence of petroleum traces in di erent soil matrices such as sea sand, red soil, and brown soil. Comparisons between results of PLS-DA and SVM were based on sensitivity, selectivity, and areas under receiver-operator curves (ROC). An innovative statistical analysis method of calculating limits of detection (LOD) and limits of decision (LD) from fits of the probability of detection was developed. Results for QCL/PLS-DA models achieved LOD and LD of 0.2% and 0.01% for petroleum/soil, respectively. The superior performance of QCL/SVM models improved these values to 0.04% and 0.003%, respectively, providing better identification probability of soils contaminated with petroleum
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