Multiple Sensor Monitoring of CFRP Drilling to Define Cutting Parameters Sensitivity on Surface Roughness, Cylindricity and Diameter

Machining parameters affects the final quality of components made in carbon fiber reinforced plastic (CFRP) composite materials. In this framework, the work here presented aims at studying the right combination of cutting speed (v(c)) and feed rate (v(f)), for dry drilling of carbon fiber reinforced plastic composite materials, which obtained better results regarding roughness, hole cylindricity, and diameter. A series of experimental tests were carried out under different drilling conditions (v(c)/v(f)), monitoring the thrust force (Fz), torque (T), and electric power (EP), to define which one can help more for industrial daily life production. Results validation was carried out using the analysis of variance, in order to relate main machining parameters cutting speed and linear feed, with thrust force, drilling torque, main spindle electric power and hole quality parameters (average roughness, cylindricity and diameter). The conclusions show that thrust force is not proportional to the cutting speed and the best combinations of cutting speed and feed were found out around the average values of tested parameters. Spindle electric power is an interesting element to take into account because it is easy to consider in real production

The Importance of Reverberation for the Design of Neonatal Incubators

Low frequency noises are predominant in neonatal intensive care units (NICUs). Some studies affirm that neonates can perceive noises from 113 Hz, and can therefore be affected by sound sources with high spectral content at low frequencies (e.g., incubator engine, air fan). Other studies suggest that reverberation amplifies noise within incubators. In this paper, the reverberation time (T, T-30) within an incubator with standard dimensions was measured in one-third octave bands. To get reliable results, the T was measured in 15 positions at the neonate's ear height, in a room with low T values (to reduce the influence of the room in the results), using an impulsive sound method. Results show a heterogeneous T distribution at the neonate's ear height, with maximum average T differences between positions of 1.07 s. The highest average T of all microphone positions is 2.27 s at 125 Hz, an extremely high mean value for such a small space. As the frequency of electrical devices in America is 60 Hz, some harmonics lay within the one-third octave band of 125 Hz, and therefore may create a very reverberant and inappropriate acoustic environment within the audible spectrum of neonates. As the acoustic environment of the incubator and the room are coupled, it is expected that the results are higher in the NICUs than in the room where the measurements were conducted, as NICUs are more reverberant. Therefore, it is recommended that the T will be limited in the international standards, and that incubator designers take it into account

Lugar, tiempo y memoria habitados por el proyecto de arquitectura

aproximarnos a la realidad, relacionando ideas en distintos mundos de la creación, hasta construir un marco para una reflexión teórica con la función de ser descriptor del proyecto. El territorio es fuente de datos con los que operar; para conocer estas realidades se propone un paseo por los límites, lugares donde operan las fuerzas en transformación. También se revisan las condiciones y relaciones del lugar con el habitar: lugar y ocupación, la habitación del hombre y, por último, la ruina. Finalmente, se observan aspectos en los que el tiempo tiene un papel fundamental: huellas producidas, huellas encontradas a partir de las que reconstruir aquella otra realidad del pasado y, por último, la huella del arquitecto. Para explicar la arquitectura constantemente nos apoyamos en imágenes; podríamos decir que son las imágenes del pensamiento. El punto de partida se sitúa en el conocimiento del espacio, filtrado a través de la percepción y de los sentidos, como ya se observó desde la posición fenomenológica; ésta es una aproximación a través de aspectos corrientes y permanentes de la arquitectura. Los trazos dibujados, el espacio construido o las palabras escritas servirán para que otros los interpreten, conozcan o no su idioma, pero no serán más que un reflejo del pensamiento.The project demands a search that continually tries to find arguments to approach reality, relating ideas in different worlds of creation, the first setting of a theoretical reflection with the function of being descriptor of the project. The territory is a source of data with which to operate; to know these realities is proposed a walk through the limits, places where the forces in transformation operate. Also conditions and relations of the place with the inhabit are revised: place and occupation, the man’s room and the ruin. Finally, we observe aspects in which time plays a fundamental role: traces produced, traces found from which to reconstruct that other reality of the past and, finally, the imprint of the architect. To explain architecture we constantly rely on images; we could say that they are the images of the thought. The starting point is situated in the knowledge of space, filtered through the perception and the senses, as already observed from the phenomenological position; this is an approximation through current and permanent aspects of architecture. Drawn strokes, built space or written words will serve for others to interpret, whether or not they know their language, but will be nothing more than a reflection of thought

Acoustic conditioning of the neonatal incubator compartment: Improvement proposal

The objective of this work focuses on the study of the main sources of noise associated with incubators and the acoustic effects that derive from them. The method that has been established is based on tests carried out under different operating conditions of the incubators. Noise levels are analyzed under different boundary conditions (Neonatal ICU and "Controlled environment rooms"). Under normal operating conditions, the levels inside the incubator are around 56 dB (A), values that exceed the maximum limits recommended by the American Academy of Pediatrics. The scope of this study is to evaluate the existing noise levels in the incubator and analyze possible design improvements. The study was carried out in the hospitals of Cadiz, Huelva, and Malaga

Factores de riesgo asociados a enfermedad renal crónica en la población adulta en cuatro estratos socioeconómicos del municipio de Guatemala

Describir el comportamiento epidemiológico de los factores de riesgo asociados a enfermedad renal crónica, en la población adulta de cuatro estratos socioeconómicos del Municipio de Guatemala en abril 2015. Estudio de tipo descriptivo, transversal, con muestreo no probabilístico por conveniencia, en 4 sectores cartográficos, 223 viviendas. Los datos se recolectaron por medio de una encuesta con base al cuestionario del método progresivo (STEPS) modificado. La prevalencia de factores de riesgo modificables asociados a enfermedad renal crónica en población adulta, en 4 estratos socioeconómicos del municipio de Guatemala fue de:sedentarismo(76%),sobrepeso/obesidad (56%), consumo de sal (36%), presión arterial elevada (31%) consumo de bebidas artificiales (30%), consumo de alcohol (21%), consumo de tabaco (1%). La prevalencia de factores de riesgo no modificables asociados a enfermedad renal crónica en población adulta, en 4 estratos socioeconómicos del municipio de Guatemala fue de: antecedente médico de hipertensión (35%), antecedente médico de de hipercolesterolemia (17%) y antecedente de diabetes mellitus. (11%). los factores de riesgo de mayor prevalencia asociado a desarrollar enfermedad renal crónica fueron sedentarismo, sobrepeso/obesidad y consumo de sal. El comportamiento epidemiológico de los factores de riesgo asociados para el desarrollo ERC fue ser sexo femenino, estar entre el rango de edad de 40 a 60 años, con un estado civil de casado, haber terminado diversificado como nivel de escolaridad, pertenecer a la población trabajadora, tener ingresos económicos en el hogar menores a Q3,247.20 y pertenecer al grupo étnico ladino

The Importance of Noise Attenuation Levels in Neonatal Incubators

Background: It is known that high noise levels can be harmful to preterm infants, causing physiological and psychological disorders. It is also known that premature babies spend a lot of time in an incubator. In this sense, many studies show that incubator noise levels can range from 45 to 70 dB. However, these differences in noise levels depend, fundamentally, on the wide range of methodology that can be used. This study aims to know the levels of noise from a fan in the incubator itself and how much it can isolate the noises coming from the outside. Methods: For this purpose, the noise levels of three incubators were measured within a sound-dampened booth for free-field audiometry. For the emission of acoustic energy, a pink noise generator was used; likewise, two microphones were placed, one inside the incubator cabin and the other outside, to determine the acoustic insulation levels of the tested incubators. Results: The incubators produced equivalent continuous sound pressure levels between 53.5 and 58 dB. Acoustic insulation analysis showed that levels varied from one incubator to another, between 5.2 and 10.4 dB. Conclusions: It is necessary to improve the acoustic insulation inside the incubator cabin and to reduce the noise levels of the motor fan. On the other hand, although the incubators are meeting the noise criteria set out in the IEC60601-2-19: 2009 standard of 60 dBA, under normal use conditions, they are still far from the limit recommended by the American Academy of Pediatrics (45 dBA).13 página

Effect of Filters on the Noise Generated by Continuous Positive Airway Pressure Delivered via a Helmet

Introduction: One of the problems that the delivery of continuous positive airway pressure (CPAP) via a helmet poses is the generation of noise. The objective of our study was to assess the effect that the use of filter has on sound pressure levels generated by the delivery of positive airway pressure at different gas flow rates. Materials and Methods: Sound pressure levels generated by neonatal helmet CPAP delivery were measured at different gas flows (20, 30, and 40 l/min) with and without a breathing filter. Noise intensity was measured by installing microphones in the inner ear of dummy heads wearing helmets. Results: The sound pressure level increased by 38% at a gas flow of 40 l/min, as compared to a gas flow of 20 l/min {74 dBA [interquartile range (IQR) 2,2] vs 52 dBA (IQR 5,9), respectively}. Using the breathing filter as a diffuser has a variety of effects on sound pressure levels according to the gas flow rate. Conclusion: The intensity of the noise generated by helmet delivery of positive airway pressure depends on the type of helmet used, gas flow, and use or not of a diffuser filter. Breathing filters with gas flows over 30 l/min might not be recommended since they would not attenuate but will rather amplify sound pressure

Evolución y análisis de la normativa de ruido en buques mercantes

Este estudio pretende describir la evolución de la normativa de ruido de los buques mercantes en las últimas cuatro décadas y a analizar sus aspectos más importantes en relación con las tripulaciones, pasaje y población expuesta en las ciudades, siguiendo los requerimientos de la Unión Europea para la reducción del impacto ambiental de los medios de transporte

Diagnosis of Noise Inside Neonatal Incubators under Free-Field Conditions

The study aims to diagnose the sound pressure levels inside incubators in a controlled environment under free-field conditions. The tests were carried out in a semi-anechoic room under the standard UNE-EN ISO 3745:2012/A1:2018 in three different operating states: off, on, and on with a temperature alarm triggered. Sound pressure levels were analyzed in three different models of incubators, both inside and outside. The main noise indices analyzed were the corrected equivalent continuous level (LKeq) and the equivalent continuous level (Leq) in third-octave bands. The results obtained under normal operating conditions showed variations among the different incubators, with overall values between 48.8 and 56.3 dBA. The influence of the alarm considerably worsened these data. The values obtained showed that premature newborns are exposed to noise levels above international recommendations. All incubators tested showed the presence of tonal components, both outside and inside the incubator cabin, and, in some cases, low-frequency components, but no impulsivity components were observed in any case

First steps towards a methodology to assess the influence of noise on a natural area

Natural sounds are integral elements of the natural environment that are frequently associated with natural parks and similar areas. They are, indisputably, inherent components of landscapes and their contents of natural and historical features, and particularly of their wildlife. Natural sounds constitute an indicator of the health of the wildlife habitat and the diverse ecosystems that comprise such areas. The present generation has an acknowledged obligation to conserve these natural resources for the benefit of those to come. In the planning process to achieve the objectives of the acoustic quality of the natural soundscape, the primary principle is the preservation of the soundscape at levels compatible with the characteristics of the park. When deficiencies are identified, mitigation measures must be taken to restore the soundscape to its natural condition. The objective of this project is to analyze the existence of “non-natural” noises foreign to the natural environment and protect the Natural Soundscape from intrusive acoustic impacts. The study was carried out on the "natural area" of Anceu, located in the municipality of Pontecaldelas in the province of Pontevedra, Galicia (Spain). © 2020, Canadian Acoustical Association. All rights reserved