SynerCrete’18: interdisciplinary approaches for cement-based materials and structural concrete: synergizing expertise and bridging scales of space and time, vol. 2

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Microwave Non-Destructive Inspection and Prediction of Modulus of Rupture and Modulus of Elasticity of Engineered Cementitious Composites (ECCs) Using Dual-Frequency Correlation

This research article presents dual-frequency correlation models for predicting the growth of elasticity and flexural strength of engineered cementitious composites (ECCs) using microwave nondestructive inspection technique. Parallel measurements of microwave properties and mechanical properties of ECC specimens were firstly undertaken in the sense of cross-disciplinary experiments. Regression models were developed via means of nonlinear regression to the measured data. The purpose of the study is: (i) to monitor the flexural strength and elasticity growth; and (ii) to predict their mature values under the influence of different initial water contents, via microwave effective conductance at early ages. It has been demonstrated that both the modulus of rupture (MOR) and modulus of elasticity (MOE) can be accurately modeled and correlated by microwave conductance using exponential functions. The moduli developed as a function of conductance whereas the regression coefficient exhibited a linear relation with water-to-binder ratio. These findings have highlighted the effectiveness of the microwave non-destructive technique in inspecting the variation of liquid phase morphology of ECCs. The dual-frequency correlation can be used for structural health monitoring, which is not only for prediction but also provides a means of verification

Propuesta de mejoramiento del pavimento rígido aplicando el método AASHTO 93 de la Av. Confraternidad Internacional Oeste, Huaraz, Ancash – 2022

El desgaste de infraestructuras viales, asociadas a la perdida de resistencia y daños en sus capas, traen inestabilidad en su durabilidad, ocasionando gastos innecesarios por mantenimiento o construcción. En este estudio se planteó como objetivo, realizar la propuesta de mejoramiento del pavimento rígido aplicando la metodología AASHTO 93 en la Av. Confraternidad Internacional Oeste Huaraz, Ancash – 2022. Donde se usó como metodología, con un tipo de investigación aplicada, con diseño o experimental y enfoque mixto. Donde se encontraron como resultados que, con base al estudio de tráfico el volumen máximo fue de 982 vehículos de NS y 854 vehículos de SN, además los ejes equivalentes son iguales a 2 898 480.54 EE, del mismo modo el coeficiente de transferencia de cargas fue de 3.80 y el coeficiente de drenaje fue 1; el módulo de elasticidad empleado fue de 4 590 000 donde la servicialidad inicial y final fueron de 4.5 y 2.5 respectivamente; los espesores variaron de 15.39 cm hasta los 24.77 cm; sin embargo, considerando un Zr=1.645, una confiabilidad de 95% y una desviación de 0.39 el espesor fue de 19.00 cm. Se concluyó, que la propuesta final es de 19.37 cm, tomando en cuenta una clasificación JPCP

Properties and Applications of Graphene and Its Derivatives

Graphene is a two-dimensional, one-atom-thick material made entirely of carbon atoms, arranged in a honeycomb lattice. Because of its distinctive mechanical (e.g., high strength and flexibility) and electronic (great electrical and thermal conductivities) properties, graphene is an ideal candidate in myriad applications. Thus, it has just begun to be engineered in electronics, photonics, biomedicine, and polymer-based composites, to name a few. The broad family of graphene nanomaterials (including graphene nanoplatelets, graphene oxide, graphene quantum dots, and many more) go beyond and aim higher than mere single-layer (‘pristine’) graphene, and thus, their potential has sparked the current Special Issue. In it, 18 contributions (comprising 14 research articles and 4 reviews) have portrayed probably the most interesting lines as regards future and tangible uses of graphene derivatives. Ultimately, understanding the properties of the graphene family of nanomaterials is crucial for developing advanced applications to solve important challenges in critical areas such as energy and health

The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology