Effect of the Pin Geometry on the Wear Behavior of Weld-Deposited Hardfacing

AbstractHarfacing welding is a widely used method on severe worn, corroded or oxidized surfaces to regain its functionality. For metal-to-metal sliding or rolling contact applications, in which oxidative wear, subsurface fatigue and adhesive wear are the main wear mechanisms, the materials usually selected are steels with a carbon contents between 0,1 and 0,7% and up to 20% of alloy content, such as martensitic tool steels. Among them, H13 tool steel has a great number of applications. Variables such as sliding speed, load, or contact stress may have decisive influence on wear rates. Laboratory tests like Pin-On-Disk (POD) are frequently used to evaluate the tribologic behaviour of different pairs of material. The objective of this work was to study the influence of the pin geometry (flat and spherical) in a POD test on the wear resistance of a weld-deposited hardfacing of H13 modified steel against low carbon steel AISI 1020 under different load and sliding speed conditions. It was observed an influence of the pin geometry on the wear rates, especially at high sliding speeds. Under light loads, the worn volume of the flat pin was greater, while under heavier loads it is the spherical pin the one with greater worn amount

Developing and validating a new multi‐dimensional scale for anti‐social behavior in a higher education setting

Abstract: The purpose of this research is to construct and validate a multi-dimensional scale of Anti-social Behaviour (hereafter ASB) in a Western higher education context (i.e. USA). To achieve this, four studies, each with a different sample, were performed. Study 1 (n = 150) followed an exploratory design to generate a pool of potential items measuring ASB. Study 2 (n = 254) explored the dimensionality of the items produced in Study 1 using Exploratory Factor Analysis (EFA) and reliability measures. Study 3 (n = 654) confirmed the factorial structure from Study 2 and assessed the measurement model invariance using structural equation modelling (SEM). Finally, Study 4 (n = 287) assessed the predictive validity of the ASB measure through testing a hypothetical path model linking ASB to narcissism and Machiavellianism via an SEM procedure. In total, our research findings conclude that the ASB measurement model is a two-factor multi-dimensional structure comprising: Interpersonal Antagonistic Behaviour (six items) as well as Indirect Distractive Behaviour (four items). The research and practical implications for universities are thereafter discussed

UTCI field measurements in an urban park in Florence (Italy)

The aim of this study is to evaluate human thermal comfort in different green area settings in the city of Florence by using the Universal Thermal Climate Index (UTCI). Field measurements of air temperature, solar radiation, relative humidity, wind speed and black globe thermometer were collected during hot summer days in various parts of Cascine Park, the biggest urban park in Florence (Italy). UTCI was evaluated over different surfaces (asphalt, gravel and grass) completely exposed to the sun or shaded by a large lime tree (Tilia × europaea). The results showed strong differences in UTCI values depending on the exposure to tree shade, while no significant difference was found among ground-cover materials when all surfaces were equally exposed to solar radiation. Future studies are needed to investigate the microclimatic effects of different tree species on UTCI

Emergency Department as an epidemiological observatory of Human Mobility: the experience of the Moroccan population

We conducted a retrospective study of the accesses to the Emergency Department registered from January 2000 to December 2014 in 5 major hospitals in the Metropolitan Area of Rome. We extrapolated data relating to patients of Moroccan origin from about 5 million total accesses, so we compared with Italians data which, in the same period, came to ED. The Moroccan population is distinguished by a larger number of diagnoses belonging to the ICD-9 code of Infectious Diseases and, more precisely, to Respiratory Infectious Diseases. There are also no differences in the assignment of such diagnoses to Moroccans with Italian citizenship, and this led to think that this could play an important role in the use of the ED and moreover that enrollment to the National Health Service may reduce its inappropriate use. Regarding to Degenerative Disorders, the result of our analysis is quite emblematic, showing that the accesses to the ED is due to Cardiovascular Diseases: 6.33% of Italians' accesses against 1.81% of Moroccans and 2.36% of Moroccans with Italian citizenship. The main explanation for this difference is, obviously, due to the age of the population: about 60% of Moroccans who accessed to ED was less than 40 years old. It is interesting how, in the field of ​​Cardiovascular Diseases, Moroccans have a lower percentage of diagnosis compared to Italians for acute diseases and a greater percentage of diagnoses for chronic diseases, suggesting once again that accesses to ED for migrants often is due to the inability to use the general services of the National Health Service. In conclusion, from the point of view of the Emergency Department, Migration Medicine still has Infectious Diseases as the main reason for access. Degenerative Disorders remain a prerogative of the Italians, but we could certainly assume that the Moroccan population would develop at some point with the aging

Low energy high angular resolution neutral atom detection by means of micro-shuttering techniques: the BepiColombo SERENA/ELENA sensor

The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA cornerstone BepiColombo mission to Mercury (in the SERENA instrument package) is a new kind of low energetic neutral atoms instrument, mostly devoted to sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV, within 1-D (2x76 deg). ELENA is a Time-of-Flight (TOF) system, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings: the incoming neutral particles directly impinge upon the entrance with a definite timing (START) and arrive to a STOP detector after a flight path. After a brief dissertation on the achievable scientific objectives, this paper describes the instrument, with the new design techniques approached for the neutral particles identification and the nano-techniques used for designing and manufacturing the nano-structure shuttering core of the ELENA sensor. The expected count-rates, based on the Hermean environment features, are shortly presented and discussed. Such design technologies could be fruitfully exported to different applications for planetary exploration.Comment: 11 page

Solar neutrino variability and its implications for solar physics and neutrino physics

Recent coordinated power-spectrum analyses of radiochemical solar neutrino data and the solar irradiance have revealed a highly significant, high-Q common modulation at 11.85 yr-1. Since the stability of this frequency points to an explanation in terms of rotation, this result may be attributable to non-spherically-symmetric nuclear burning in a solar core with sidereal rotation frequency 12.85 yr-1. The variability of the amplitude (on a timescale of years) suggests that the relevant nuclear burning is variable as well as asymmetric. Recent analysis of Super-Kamiokande solar neutrino data has revealed r-mode-type modulations with frequencies corresponding to a region with sidereal rotation frequency 13.97 yr-1. If this modulation is attributed to the RSFP (Resonant Spin Flavor Precession) process, it provides a measurement of the rotation rate deep in the radiative zone. These two results suggest that the core rotates significantly more slowly than the radiative zone. If one accepts an upper limit of 7 MG for the Sun's internal magnetic field, an RSFP interpretation of the Super-Kamiokande results leads to a lower limit of 10-12 Bohr magnetons for the neutrino transition magnetic moment.Comment: 12 pages, 3 figure

SEíS: Sistema basado en tecnologías semánticas para integrar la información energética de los edificios

Access to reliable energy related data is a fundamental factor when taking decisions that help to improve the energy efficiency of buildings. The increase in the amount of data we have available has led to the need to develop information systems that facilitate the analysis of such data to the agents which are present throughout the building life cycle, from the design phase to maintenance. Semantic web technologies provide a solution to interlink distributed data sources. This requires the construction of shared vocabularies (i.e. ontologies) which capture the meaning that users give to the data and facilitate access to them. As yet there are no consolidated methods to build these vocabularies. This article presents the methodology developed to create SEíS, an energy information system that uses semantic technologies to integrate energy related data and to facilitate services to the different agents involved throughout the stages of the building life cycle.El acceso a los datos relacionados con la energía es un factor fundamental para tomar decisiones que ayuden a mejorar la eficiencia energética de los edificios. El incremento de la cantidad de datos disponibles ha llevado a la necesidad de desarrollar sistemas de información que faciliten el análisis de los mismos a los agentes que participan a lo largo del ciclo de vida del edificio, desde el diseño hasta el mantenimiento. Las tecnologías de la web semántica proporcionan una solución para interconectar fuentes de datos distribuidas. Esto requiere la construcción de vocabularios compartidos (i.e. ontologías) que capten el significado que le dan los usuarios a la información y faciliten el acceso a los datos. No existen aún métodos consolidados para construir estos vocabularios. En este artículo se presenta la metodología desarrollada para crear SEíS, un sistema de información energética que utiliza tecnologías semánticas para integrar datos energéticos y facilitar servicios a los agentes que intervienen a lo largo de las fases del ciclo de vida del edificio

Chapter 4: Infrastructure Considerations for CO2 Utilization, in: Carbon Dioxide Utilization Markets and Infrastructure Status and Opportunities: A First Report

This chapter describes considerations for developing infrastructure for carbon dioxide (CO2) utilization, taking into account the CO2-derived products identified in Chapter 3 and the existing infrastructure discussed in Chapter 2. Infrastructure needs throughout the CO2 utilization value chain are examined, from capture to purification, transportation, conversion, and, where applicable, transportation of the CO2-derived product. Requirements for enabling infrastructure, namely, clean electricity, hydrogen, water, land, and energy storage, are also considered

Chapter 6: Priority Infrastructure Opportunities for CO2 Utilization, in: Carbon Dioxide Utilization Markets and Infrastructure Status and Opportunities: A First Report

Building on the analyses of carbon dioxide (CO2)-derived products, infrastructure requirements, and policy, regulatory, and societal considerations discussed in Chapters 2 through 5, this chapter presents a summary of priority infrastructure opportunities to enable CO2 utilization. The chapter begins by describing options for CO2 utilization infrastructure funding based on current policy and regulatory regimes, and considering successful examples in related industries. It then examines near-term opportunities for CO2 utilization infrastructure investments, as well as near-term actions to enable longerterm deployment options. A primary consideration for these opportunities is the ability of CO2 utilization to participate in a future circular carbon economy, which depends on the type of CO2 source, CO2-derived product lifetime, and life cycle emissions of other process inputs. The chapt