Micro-Cantilever Testing Of Cementitious Materials Under Various Loading Conditions

Nanoindentation is usually used to investigate local elastic properties and hardness of materials. In this paper, the nanoindenter served as a loading tool to perform micro scale bending tests and measure the global response of micro-scale specimens. For testing, cement paste cantilever beams with a square cross-section of 300 μm × 300 μm were...

Combined experimental and numerical study of uniaxial compression failure of hardened cement paste at micrometre length scale

The aim of this work is to investigate the mechanical performance of hardened cement paste (HCP) under compression at the micrometre length scale. In order to achieve this, both experimental and numerical approaches were applied. In the experimental part, micrometre sized HCP specimens were fabricated and subjected to uniaxial compression by...

Experimentally informed fracture modelling of interfacial transition zone at micro-scale

The aim of this work is to predict the micromechanical properties of interfacial transition zone (ITZ) by combining experimental and numerical approaches. In the experimental part, hardened cement paste (HCP) cantilevers (200 μm × 100 μm × 100 μm) attached to a quartzite aggregate were fabricated and tested using micro-dicing saw and...

Abundant grain boundaries activate highly efficient lithium ion transportation in high rate Li₄Ti₅O₁₂ compact microspheres

It is a huge challenge for high-tap-density electrodes to achieve high volumetric energy density but without compromising the ionic transportation. Herein, we prepared compact Li₄Ti₅O₁₂ (LTO) microspheres consisting of densely packed primary nanoparticles. The real space distribution of lithium ions inside the...

81 supra-THz beams generated by a Fourier grating and a quantum cascade laser

Large heterodyne receiver arrays (~100 pixel) allow astronomical instrumentations to map more area within limited space mission lifetime. One challenge is to generate multiple local oscillator (LO) beams. Here, we succeeded in generating 81 beams at 3.86 THz by combining a reflective, metallic Fourier grating with an unidirectional antenna...

Static and Fatigue Tests on Cementitious Cantilever Beams Using Nanoindenter

Cement paste is the main binding component in concrete and thus its fundamental properties are of great significance for understanding the fracture behaviour as well as the ageing process of concrete. One major aim of this paper is to characterize the micromechanical properties of cement paste with the aid of a nanoindenter. Besides, this paper...

Creation of an anti-imaging system using binary optics

We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from...

Velocity analysis of simultaneous-source data using high-resolution semblance: Coping with the strong noise

Direct imaging of simultaneous-source (or blended) data, without the need of deblending, requires a precise subsurface velocity model. In this paper, we focus on the velocity analysis of simultaneous-source data using the normal moveout-based velocity picking approach.We demonstrate that it is possible to obtain a precise velocity model directly...

Dynamic Beam Steering from a Subwavelength Slit by Selective Excitation of Guided Modes

Dynamic control of the direction of radiation of the light emanating from a subwavelength slit carved out of a thin metal film is experimentally demonstrated. This is achieved by selective excitation of the individual guided modes in the slit by setting the phase of three coherent laser beams. By changing the voltage across a piezoelement, we...

Plasmon switching: Observation of dynamic surface plasmon steering by selective mode excitation in a sub-wavelength slit

We report a plasmon steering method that enables us to dynamically control the direction of surface plasmons generated by a two-mode slit in a thin metal film. By varying the phase between different coherent beams that are incident on the slit, individual waveguide modes are excited. Different linear combinations of the two modes lead to...

Coherence converting plasmonic hole arrays

Simulations are presented that demonstrate that the global state of spatial coherence of an optical wavefield can be altered on transmission through an array of subwavelength-sized holes in a metal plate that supports surface plasmons. It is found that the state of coherence of the emergent field strongly depends on the separation between the...