The use of arc-erosion as a patterning technique for transparent conductive materials

Within the framework of cost-effective patterning processes a novel technique that saves photolithographic processing steps, easily scalable to wide area production, is proposed. It consists of a tip-probe, which is biased with respect to a conductive substrate and slides on it, keeping contact with the material. The sliding tip leaves an insulating path (which currently is as narrow as 30 μm) across the material, which enables the drawing of tracks and pads electrically insulated from the surroundings. This ablation method, called arc-erosion, requires an experimental set up that had to be customized for this purpose and is described. Upon instrumental monitoring, a brief proposal of the physics below this process is also presented. As a result an optimal control of the patterning process has been acquired. The system has been used on different substrates, including indium tin oxide either on glass or on polyethylene terephtalate, as well as alloys like Au/Cr, and Al. The influence of conditions such as tip speed and applied voltage is discusse

Análisis de Tensiones Residuales Inducidas en Aleaciones Metálicas por Tratamientos Superficiales mediante Ondas de Choque Generadas por Láser

En el presente artículo se plantea un estudio sobre la medida de tensiones residuales mediante el método del taladro en banda extensométrica (o agujero ciego) aplicado en probetas de aluminio 2024-T351, previamente tratadas superficialmente mediante laser shock processing (método de tratamiento superficial por ondas de choque generadas por láser, conocido como LSP). Finalmente, se realiza una comparación entre los resultados experimentales obtenidos al medir las tensiones residuales obtenidas en probetas tratadas mediante LSP y los valores obtenidos mediante un modelo de simulación

Metrología óptica dimensional submicrométrica para determinación de espesores en sub-micro estructuras

En este trabajo se presenta el análisis de una técnica de metrología óptica utilizada para el control de procesos en línea en la fabricación de microchips. Se obtienen los perfiles de reflectividad en función del ángulo de incidencia para una longitud de onda de 675 nm, para los estados de polarización s y p. Se obtiene un modelo teórico para una estructura multicapa, con la que se pueden calcular de forma sencilla las propiedades ópticas y dimensiones de las capas. Se obtiene la incertidumbre de la técnica de medida.-In this work is presented the analysis of a technique of optical metrology widely used in controlling on- line process in fabrication of microchips. Reflectivity profiles as a function of angle of incidence are obtained for a wavelength of 675 nm. A theoretical model for a Si/ SiO2 multilayer stack is also obtained, which can be used to calculate both the thickness and the optical properties of the layers. A calculation of the uncertainty for the measurement technique is also performed

Efficacy of baths with mineral-medicinal water in patients with fibromyalgia: a randomized clinical trial

The layout of this study, designed as a randomized crossover clinical trial, is to evaluate the efficacy of an intervention with mineral-medicinal water from As Burgas (Ourense) in patients suffering from fibromyalgia. Pre-intervention: randomization of group A and group B. Intervention: Phase 1: Group A: 14 baths in thermal water for a month and standard pharmacological treatment; group B, standard pharmacological treatment. Rest period, 3 months. Phase 2: Gruop A, standard treatment and Grou B, 14 baths in thermal water for a month plus standard treatment. The Fibromyalgia Impact Questionnaire (FIQ) was used; this grades from 1 (minimum) to 10 (maximum) the impact of the illness, which was measured in both phases. 25 patients were included in each group and the study was concluded with 20 patients in group A and 20 in group B. The intervention group obtained, once the baths finished, a mean score of 60,3 (±11,8) and the control group of 70,8 (±13,0) (p <0,001). Three months later, the intervention group presented a mean score of 64,4 (±10,6) and the control group of 5,0 (±11,3) (p <0,001). We can therefore conclude that the simple baths with mineral-medicinal water from As Burgas can make an improvement on the impact caused by fibromyalgia

An Experimental and Numerical Approach to Multifunctional Urban Surfaces through Blue Roofs

Uncontrolled urban growth causes a number of problems associated with land use, stormwater management and energy generation. Sustainable Urban Drainage Systems (SUDS) are positioned as an alternative to traditional constructive solutions, contributing towards the generation of multifunctional urban spaces for efficient stormwater management and energy consumption reduction. Nevertheless, this combined goal calls for a deeper understanding of the heat transfer processes that govern the temperature performance in SUDS in order to be further validated as infrastructure to house renewable energy elements. This study intends to determine the thermal properties of two types of blue roofs under extreme conditions of performance (wet and dry), depicting the operation features of their layers and comparing their performances based on the materials used. With this aim, a hybrid experimental methodology, combining laboratory and numerical modelling, was designed using standardized equipment (ISO 8990:1994 and ASTM C1363-05), improving previous methods proposed in the study of the thermal properties of SUDS. The section with expanded clay improved the hydraulic capacity by 4.8%. The section without expanded clay increased its thermal transmittance value by 64.9% under wet conditions. It was also found that the presence of water increased the equivalent thermal conductivity in both sections by 60%

Exploring the Chemistry of Ocimum Species under Specific Extractions and Chromatographic Methods: A Systematic Review

Ocimum is considered the largest genus in the Lamiacea family. The genus includes basil, a group of aromatic plants with a wide range of culinary uses that nowadays draws attention for its medicinal and pharmaceutical potential. This systematic review intends to explore the chemical composition of nonessential oils and their variation across different Ocimum species. Moreover, we aimed to identify the state of knowledge regarding the molecular space in this genus as well as the different methods of extraction/identification and geographical location. Seventy-nine eligible articles were selected for the final analysis, from which we extracted more than 300 molecules. We found that the countries with the highest number of studies into Ocimum species are India, Nigeria, Brazil, and Egypt. However, from all known species of Ocimum, only 12 were found to have an extensive chemical characterization, particularly Ocimum basilicum and Ocimum tenuiflorum. Our study focused especially on alcoholic, hydroalcoholic, and water extracts, in which the main techniques for compound identifications are GC-MS, LC-MS, and LC-UV. Across the compiled molecules, we found a wide variety of compounds, especially flavonoids, phenolic acids, and terpenoids, suggesting that this genus could be a very useful source of possible bioactive compounds. The information collected in this review also emphasizes the huge gap between the vast number of Ocimum species discovered and the number of studies in each of them that determined the chemical characterization.We thank the Universidad de Las Américas, Quito, Ecuador, for the financial support of the PhD students A. Beltrán-Noboa and M. Guevara-Terán. We also want to thank Universidad de Las Américas for supporting A. Jordan-Álvarez and E. Tejera and Y. Castillo, and Universidad San Francisco de Quito, Ecuador, for supporting J.M. Alvarez-Suarez

Microconformado de Materiales Metálicos mediante Pulsos Láser en el Dominio de ns

La demanda de miniaturización introducida, entre otros, por la industria de fabricación de MEMS (Micro Electro Mechanical Systems), hace necesario caracterizar y validar los procesos que emplean el láser en el microconformado de materiales metálicos a escala submilimétrica. Como alternativa al microconformado térmico, que hace uso de las deformaciones de origen térmico inducidas por la radiación láser, el microconformado mediante pulsos láser en el dominio de ns hace posible el conformado de materiales metálicos manteniendo, o incluso mejorando, las propiedades mecánicas de los mismos debido a la inducción de tensiones residuales de compresión en la superficie de la pieza tratada. Se presenta en este trabajo el estudio teórico y experimental del microconformado láser mediante la caracterización de diversas pruebas elementales. Miniaturization of components demanded by MEMS (Micro Electro Mechanical Systems) industry, makes necessary the validation of the manufacturing processes applied to submillimetric metallic materials in which laser is used. As an alternative to thermal microforming in which laser induced thermal fields are responsible for the forming phenomena, the use of ns laser pulses makes possible microforming of metallic materials preserving, or even improving, their mechanical properties, due to the induction of residual stresses in the surface. In the present paper experimental tests and FEM simulation results on nanosecond time scale laser microforming are presented

Texture-induced enhancement of the magnetocaloric response in melt-spun DyNi2 ribbons

"The magnetocaloric properties of melt-spun ribbons of the Laves phase DyNi2 have been investigated. The as-quenched ribbons crystallize in a single-phase MgCu2-type crystal structure (C15; space group Fd (3) over barm) exhibiting a saturation magnetization and Curie temperature of M-S = 157 +/- 2 A m(2) kg(-1) and T-C = 21.5 +/- 1 K, respectively. For a magnetic field change of 2 T, ribbons show a maximum value of the isothermal magnetic entropy change vertical bar Delta S-M(peak)vertical bar = 13.5 J kg(-1) K-1, and a refrigerant capacity RC = 209 J kg(-1). Both values are superior to those found for bulk polycrystalline DyNi2 alloys (25% and 49%, respectively). In particular, the RC is comparable or larger than that reported for other potential magnetic refrigerants operating at low temperatures, making DyNi2 ribbons promising materials for use in low-temperature magnetic refrigeration applications.

Vulnerabilidad ante la COVID-19 en adultos mayores con enfermedad cardiovascular

Introduction: the identification of vulnerable population groups through active surveys is aimed at preventing contagion through different measures or interventions.Objective: to characterize vulnerable older adults to Covid-19 with a personal pathological history of cardiovascular diseases.Method: an observational, descriptive and cross-sectional study was conducted at No-3 Family Doctor’s Office belonging to Manuel Piti Fajardo Rivero University Polyclinic in Las Tunas province, including the period defined between March and July 2020. The target group included 90 old people from 65 years or older having a personal pathological history of cardiovascular disease, working with all of them.Results: it was found a predominance of female sex (70 %) and the age group from 65 to 70 (35,6 %). According to personal medical history, 100 % of older adults were hypertensive, and 70 % suffered from cardiovascular diseases other than hypertension; 85,7 % of the patients maintained a standard therapeutic adherence to the treatments for the underlying diseases; 60 % of the patients were compensated during the period studied.Conclusions: the vulnerable older adults having a history of cardiovascular diseases were mainly female. Hypertension was shown as the main cardiovascular antecedent. Standard therapeutic adherence and stable underlying diseases were common in these patients.Introducción: la identificación de grupos poblacionales vulnerables a través de pesquisa activa tiene como fin prevenir la infección a través de diferentes medidas o intervenciones.Objetivo: caracterizar a los adultos mayores vulnerable a la COVID-19 con antecedentes personales de enfermedades cardiovasculares.Método: se realizó un estudio observacional, descriptivo y transversal en el Consultorio Médico de la Familia 3 del Policlínico Universitario “Manuel Piti Fajardo Rivero” de la provincia las Tunas el periodo definido entre marzo a julio de 2020. El universo estuvo constituido por 90 adultos mayores con antecedentes patológicos personales de enfermedad cardiovascular con edad igual o mayor a 65 años, trabajándose con la totalidad.Resultados: se encontró predominio del sexo femenino (70 %) y el grupo de edades de 65 a 70 (35,6 %). El 100 % de los adultos mayores según antecedentes patológicos personales fueron hipertensos, y el 70 % presentó enfermedades cardiovasculares diferentes a la hipertensión arterial. El 85,7 % de los pacientes mantuvo una adherencia terapéutica regular a los tratamientos de las enfermedades de base. El 60 % de los pacientes se mostró compensado en el periodo de estudioConclusiones: los adultos mayores vulnerables con antecedentes cardiovasculares fueron principalmente féminas. La hipertensión arterial se mostró como principal antecedente cardiovascular. La adherencia terapéutica regular y la compensación de la enfermedad de base fue común en los pacientes

Texture-induced enhancement of the magnetocaloric response in melt-spun DyNi2 ribbons

"The magnetocaloric properties of melt-spun ribbons of the Laves phase DyNi2 have been investigated. The as-quenched ribbons crystallize in a single-phase MgCu2-type crystal structure (C15; space group Fd (3) over barm) exhibiting a saturation magnetization and Curie temperature of M-S = 157 +/- 2 A m(2) kg(-1) and T-C = 21.5 +/- 1 K, respectively. For a magnetic field change of 2 T, ribbons show a maximum value of the isothermal magnetic entropy change vertical bar Delta S-M(peak)vertical bar = 13.5 J kg(-1) K-1, and a refrigerant capacity RC = 209 J kg(-1). Both values are superior to those found for bulk polycrystalline DyNi2 alloys (25% and 49%, respectively). In particular, the RC is comparable or larger than that reported for other potential magnetic refrigerants operating at low temperatures, making DyNi2 ribbons promising materials for use in low-temperature magnetic refrigeration applications.