Quantifying moisture transport in cementitious materials using neutron radiography

A portion of the concrete pavements in the US have recently been observed to have premature joint deterioration. This damage is caused in part by the ingress of fluids, like water, salt water, or deicing salts. The ingress of these fluids can damage concrete when they freeze and expand or can react with the cementitious matrix causing damage. To determine the quality of concrete for assessing potential service life it is often necessary to measure the rate of fluid ingress, or sorptivity. Neutron imaging is a powerful method for quantifying fluid penetration since it can describe where water has penetrated, how quickly it has penetrated and the volume of water in the concrete or mortar. Neutrons are sensitive to light atoms such as hydrogen and thus clearly detect water at high spatial and temporal resolution. It can be used to detect small changes in moisture content and is ideal for monitoring wetting and drying in mortar exposed to various fluids. ^ This study aimed at developing a method to accurately estimate moisture content in mortar. The common practice is to image the material dry as a reference before exposing to fluid and normalizing subsequent images to the reference. The volume of water can then be computed using the Beer-Lambert law. This method can be limiting because it requires exact image alignment between the reference image and all subsequent images. A model of neutron attenuation in a multi-phase cementitious composite was developed to be used in cases where a reference image is not available. The attenuation coefficients for water, un-hydrated cement, and sand were directly calculated from the neutron images. The attenuation coefficient for the hydration products was then back-calculated. The model can estimate the degree of saturation in a mortar with known mixture proportions without using a reference image for calculation. ^ Absorption in mortars exposed to various fluids (i.e., deionized water and calcium chloride solutions) were investigated. It has been found through this study that small pores, namely voids created by chemical shrinkage, gel pores, and capillary pores, ranging from 0.5 nm to 50 µm, fill quickly through capillary action. However, large entrapped and entrained air voids ranging from 0.05 to 1.25 mm remain empty during the initial filling process. In mortar exposed to calcium chloride solution, a decrease in sorptivity was observed due to an increase in viscosity and surface tension of the solution as proposed by Spragg et al 2011. This work however also noted a decrease in the rate of absorption due to a reaction between the salt and matrix which results in the filling of the pores in the concrete. ^ The results from neutron imaging can help in the interpretation of standard absorption tests. ASTM C1585 test results can be further analyzed in several ways that could give an accurate indication of the durability of the concrete. Results can be reported in depth of penetration versus the square root of time rather than mm3 of fluid per mm2 of exposed surface area. Since a known fraction of pores are initially filling before reaching the edge of the sample, the actual depth of penetration can be calculated. This work is compared with an ‘intrinsic sorptivity’ that can be used to interpret mass measurements. Furthermore, the influence of shrinkage reducing admixtures (SRAs) on drying was studied. Neutron radiographs showed that systems saturated in water remain “wetter” than systems saturated in 5% SRA solution. The SRA in the system reduces the moisture diffusion coefficient due an increase in viscosity and decrease in surface tension. Neutron radiography provided spatial information of the drying front that cannot be achieved using other methods

Sistema De Gestión De Calidad Basado En La Norma Iso 9001:2015 Para Mejorar La Eficiencia De La Empresa Proinco Mdg S.A.C, 2018

La presente investigación tiene como objetivo implementar un SGC basado en la norma ISO 9001:2015 que permita mejorar la eficiencia de la empresa PROINCO MDG S.A.C, para lo cual se empleó un método deductivo, con una investigación de tipo aplicativo de diseño pre experimental con prueba y post prueba. Se empleó un check list de verificación y escala de Likert para determinar el cumplimiento inicial de los requisitos de la norma, se aplicó una entrevista a los gerentes de la organización para determinar su perspectiva respecto al Sistema de Gestión de calidad, se utilizaron también los indicadores de eficiencia y los diagramas de Pareto e Ishikawa para el análisis de los proyectos de la empresa, obteniendo como resultado un 39% de cumplimiento inicial de la norma y eficiencias de 66%,87% y 67% en base a tiempo, costo y horas hombre. Se implementó el manual de calidad y procedimientos de la empresa dando como resultado una mejora de la eficiencia en base al tiempo en 91%, en base al costo en 98% y horas hombre en 91%, elevando también su cumplimiento de la norma a 85% en general. Se realizó la prueba de hipótesis planteada que corrobora los resultados, con la aplicación de la prueba estadística de T-student obteniendo un valor de significancia de p< 0.05. Lo que permite concluir que la implementación del Sistema de Gestión de Calidad mejora la eficiencia de la empresa PROINCO MDG S.A.C

Niveles de agresividad en estudiantes del tercer año de secundaria de la Institución Educativa Particular Trilce Villa el Salvador, Lima 2017

La presente investigación fue de tipo aplicada – descriptiva, no experimental, porque se evaluó a la muestra en su ambiente natural, sin intervenir ni manipular la variable, a su vez fue de corte transaccional, ya que se recolectaron datos en un solo momento; el objetivo principal fue determinar los niveles de agresividad en los estudiantes de tercer año de secundaria de la Institución Educativa Particular Trilce Villa el Salvador, buscando identificar cuáles es el nivel de Agresión Física, verbal, hostilidad e Ira. Se evaluó a una muestra representativa de 98 alumnos, pertenecientes a las 3 secciones de tercer año (A, B y C), a quienes se les aplicó el Cuestionario de Agresividad (AQ) de Buss y Perry (1992), que fue adaptado en nuestro país en el 2012 por Matalinares, M. et al. Al procesar los datos se encontró que de los 98 alumnos evaluados, tan solo el 22% obtuvo un nivel bajo de agresividad, mientras que el 37% un nivel medio, el 29% un nivel alto y el 12% un nivel muy alto de agresividad, de acuerdo a la investigación se evidencia que aproximadamente el 78% de los alumnos evaluados poseen agresividad desde un nivel medio con tendencia a niveles altos y muy altosThe present research was applied - descriptive, not experimental, because the sample was evaluated in its natural environment, without intervention or manipulation of the variable, in turn it was transactional cut, since data were collected in a single moment; The main objective was to determine the levels of aggressiveness in the third year of high school students of the Institución Educativa Particular Trilce Villa el Salvador, seeking to identify the level of Physical Aggression, verbal, hostility and anger. A representative sample of 98 students, belonging to the 3 third-year sections (A, B and C), who were assessed using the Buss and Perry Questionnaire of Aggressiveness (AQ) (1992), which was adapted in Our Country in 2012 by Matalinares, M. et al. When processing the data found in the 98 students evaluated, only 22% had a low level of aggressiveness, while 37% had an average level, 29% had a high level and 12% had a very high level of aggressiveness

Sex Workers Should Be Included in COVID-19 Vaccination Efforts.

As the COVID-19 pandemic takes its toll on citizens across the globe, more people turn to sex work for survival. Because sex work is inherently physical and intimate, sex workers become defenseless against the virus and act as a bridge for transmitting the virus to their clients and society. Often, sex workers are the victims of violence and homelessness, and are devoid of health-care facilities, including HIV treatment, and are frequently exposed to a large number of individuals as dictated by the nature of their work. Their survival instincts would drive them to take part in their usual job to earn money, despite added health risks, to survive and feed their families. Worldwide, sex workers do not fully benefit from the COVID-19 responses, particularly in health, social, and economic aid assistance and services. Hence, it is essential to include this vulnerable population in the COVID-19 vaccination programs to halt the further spread of the virus

Dispersion and Effects of Metal Impregnated Granular Activated Carbon Particles on the Hydration of Antimicrobial Mortars

Granular activated carbon (GAC) particles impregnated with antimicrobial metals were incorporated into cementitious materials for the express purpose of inhibiting biogenic concrete corrosion. We report herein the influence of such metal-laden GAC particles on the hydration of cement mortars when substituted for fine aggregate, as well as the dispersion of metal in the cured matrix. Isothermal calorimetry was utilized to study the influence of GAC without and with copper and/or cobalt on select hydration characteristics of ordinary portland cement (OPC) mortars. When 1% of the fine aggregate mass was replaced with GAC particles of similar size, total evolved heat in all formulations was similar, regardless of GAC pretreatment. However, as the substitution approached 10% of the fine aggregate mass, metal-laden GAC formulations imparted delays in heat liberation and lowered heat fluxes. Results also substantiate that metal-laden GAC particles participate in the enhanced uptake of the calcium that is normally liberated during cement mixing and that the water delivered with GAC particles is not readily available during the first 142&nbsp;h of curing. Electron microprobe analysis (EMPA) elucidated that copper and cobalt were homogenously distributed throughout the cement paste with metal-laden GAC, with these metals concentrations localized in a 50&ndash;100&nbsp;&mu;m region surrounding the GAC particles. Compressive strengths were not affected by the presence of metal-impregnated GAC in the concentration ranges tested and reported herein. &nbsp;</p

The North American Consortium for the Study of Endâ Stage Liver Diseaseâ Acuteâ onâ Chronic Liver Failure Score Accurately Predicts Survival: An External Validation Using a National Cohort

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153715/1/lt25696_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153715/2/lt25696.pd

Diseñar e implementar guías y protocolos en el proceso de selección de contratación de personal de la empresa social del estado ESE Popayán.

imagen, tablas, fichas.De acuerdo con la contratación de personal realizada por la Empresa Social del Estado ESE Popayán, podemos evidenciar que no existe un protocolo en este campo por lo tanto mediante este trabajo vamos a diseñar e implementar este protocolo, dado que hoy en día los Protocolos tienen un gran componente en la organización empresarial, como guía para buscar a los mejores y potencializar sus habilidades, por lo que existen normas que ayudan a mejorar la funcionalidad y mejora los resultados proyectados. Las técnicas protocolarias sirven para optimizar las competencias tanto de los empleados como de la Empresa Social del Estado ESE Popayán, puesto que nos ayuda a generar mayor confianza y encontrar un buen personal idóneo para el desempeño de las actividades tanto misionales por parte de personal de planta como apoyo por parte de contratistas, según sea la necesidad dando un plus profesional a la ESE Popayán.According to the hiring of personnel carried out by Empress Social del Estado ESE Popayan, we can show that there is no protocol in this field, therefore through this work we are going to design and implement this protocol, given that nowadays the Protocols have a large component in the organization business, as a guide to find the best and enhance their skills, so there are rules that help improve functionality and improve projected results. The protocol techniques serve to optimize the competencies of both the employees and the Social Enterprise of the State ESE Popayàn, since it helps us to generate greater confidence and find good suitable personnel for the performance of both missionary activities by plant personnel as support from contractors, depending on the need, giving ESE Popayan a professional bonus

Readout of a quantum processor with high dynamic range Josephson parametric amplifiers

We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $\Omega$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs.Comment: 9 pages, 8 figure