Recycling of waste incineration bottom ash in the production of interlocking concrete bricks

This study presents an experimental investigation on the recycling of waste incineration bottom ash (IBA) as a fine aggregate in the production of interlocking concrete bricks (ICB). Before being used, the concentration of heavy metal in IBA was determined to confirm it is a non-toxic material. In this study, the IBA was used to replace crushed sand (CSA) in the brick mixtures at different replacement levels of 0%, 25%, 50%, 75%, and 100% (by volume). The ICB samples were checked for dimensions, visible defects, compressive strength, bending strength, water absorption, and surface abrasion in accordance with the related Vietnamese standards. The test results demonstrated that the IBA used in this study was a non-toxic material, which can be widely used for construction activities. All of the ICB samples prepared for this study exhibited a nice shape with consistent dimensions and without any visible defects. The incorporation of IBA in the brick mixtures affected engineering properties of the ICB samples such as a reduction in the compressive strength and bending strength and an increment in water absorption and surface abrasion of the brick samples. As a result, the compressive strength, bending strength, water absorption, and surface abrasion values of ICB samples at 28 days were in the ranges of 20.6 – 34.9 MPa, 3.95 – 6.62 MPa, 3.8 – 7.2%, and 0.132 – 0.187 g/cm2, respectively. Therefore, either partial or full replacement of CSA by IBA, the ICB with grades of M200 – M300 could be produced with satisfying the TCVN 6476:1999 standard in terms of dimensions, visible defects, compressive strength, water absorption, and surface abrasion. These results demonstrated the high applicability of the local IBA in the production of the ICB for various construction application purposes. Keywords: interlocking concrete brick; waste incineration bottom ash; visible defect; compressive strength; bending strength; water absorption; surface abrasion.

A Convolutional Neural Network-Based Classification and Decision-Making Model for Visible Defect Identification of High-Speed Train Images

In high-speed train safety inspection, two changed images which are derived from corresponding parts of the same train and photographed at different times are needed to identify whether they are defects. The critical challenge of this change classification task is how to make a correct decision by using bitemporal images. In this paper, two convolutional neural networks are presented to perform this task. Distinct from traditional classification tasks which simply group each image into different categories, the two presented networks are capable of inherently detecting differences between two images and further identifying changes by using a pair of images. In doing so, even in the case that abnormal samples of specific components are unavailable in training, our networks remain capable to make inference as to whether they become abnormal using change information. This proposed method can be used for recognition or verification applications where decisions cannot be made with only one image (state). Equipped with deep learning, this method can address many challenging tasks of high-speed train safety inspection, in which conventional methods cannot work well. To further improve performance, a novel multishape training method is introduced. Extensive experiments demonstrate that the proposed methods perform well.

Genetic and environmental canalization are not associated among altitudinally varying populations of Drosophila melanogaster

Organisms are exposed to environmental and mutational effects influencing both mean and variance of phenotypes. Potentially deleterious effects arising from this variation can be reduced by the evolution of buffering (canalizing) mechanisms, ultimately reducing phenotypic variability. As such, there has been interest regarding the plausible conditions that enable canalizing mechanisms to evolve. Under some models, the circumstances under which genetic canalization evolves is limited, despite apparent empirical evidence for it. It has been argued that canalizing mechanisms for mutational effects may evolve as a correlated response to environmental canalization (the congruence model). Yet, empirical evidence has not consistently supported the prediction of a correlation between genetic and environmental canalization. In a recent study, a population of Drosophila melanogaster adapted to high altitude showed evidence of genetic decanalization relative to those from low-altitudes. Using strains derived from these populations, we tested if they also varied for environmental canalization, rearing them at different temperatures. Using wing morphology, we quantified size, shape, cell (trichome) density and frequencies of mutational defects. We observed the expected differences in wing size and shape, cell density and mutational defects between the high- and low-altitude populations. However, we observed little evidence for a relationship between a number of measures of environmental canalization with population or with visible defect frequency. Our results do not support the predicted association between genetic and environmental canalization.

Understanding Idiopathic Spinal Cord Herniation – A Comprehensive Review of Imaging and Literature

Idiopathic spinal cord herniation (ISCH) is displacement of spinal cord through a dural or arachnoidal defect. Most patients present with back pain or myelopathy, paresthesia, and sensory or motor weakness. Imaging findings include anterior displacement of the cord with possible kink, no filling defect on CT myelography, and no restricted diffusion/mass lesion on magnetic resonance imaging. Abrupt kink in the spinal cord or widened cerebrospinal fluid (CSF) space can be caused by a variety of reasons. The differential considerations include arachnoid web, intradural extramedullary epidermoid or arachnoid cyst, abscess or cystic schwannoma. We discuss the features, imaging, differentials, and treatment of ISCH as a rare cause of such kink in the cord. While reading such cases, a radiologist should include the location, segments involved, cord signal abnormality, visible defect, scalpel sign or C–sign, ventral cord kink, nuclear trail sign, the ventral CSF space preservation, or obliteration and the type.

Automatic Detection of Surface Defects in Industrial Materials Based on Image Processing

In the field of industry, corrosion and defects are amongst the most frequent operations. Industrial Materials have periodic defects that are difficult to detect during production even by experienced human inspectors. Defects are difficult to detect during production even by experienced human inspectors. Usually, the colour transfer process contains an image segmentation phase and an image construction phase. Therefore, we introduce an image processing method for automatically detecting the defects in surfaces. We show how barely visible defect can be optically enhanced to improve annual assessment as well as how descriptor-based image processing and machine learning can be used to allow automated detection. Image enhancement is performed by applying manual calculation. We implement this simulation using MATLAB R2013a. Results show that the proposed allows training both tested classifiers with good classification rates around 98.9%.

Quantum-size effects in visible defect photoluminescence of colloidal ZnO quantum dots: a theoretical analysis

A theoretical model elucidating green photoluminescence of ZnO quantum dots via quantum size effects of electronic states and their overlap with a deeply trapped hole.

Non-Visible Defect Analysis by the Nanoprobing Methodology

This paper explains how the authors used nanoprobing techniques and electrical characterization to trace a die failure to a problem with the photoresist used to mask the wafer for ion implantation. Nanoprobing and leakage current measurements revealed significant differences between the inner and outer fingers of a multi-finger native transistor. Based on simulations, the differences can be attributed to severe scattering at the active edge of the Pwell due to problems with the photoresist, resulting in nonuniform doping profiles and die failure.

Fracture Behavior of Cu/Cu–WCP Layered Composites

In order to understand the fracture mechanisms of Cu/CuWCP layered composites. An in-situ experimental study was carried out to investigate the behavior of the composites under uniaxial tensile loading. The specimens were manufactured by vacuum hot-pressed sintering technique, microscopic observations displayed that the microstructure of Cu/CuWCP layered composites distribute uniformly, and have no visible defect at interface. In situ tensile tests were performed in a scanning electron microscope (SEM) and the tensile strengths, failure modes of composites were measured. From the in situ experiments, the stages of nucleation, growth and coalescence of cracks in the vicinity of particles are well observed and understood. The results indicated that microcrack initiation happens at particle agglomeration and the matrix-particle interface because bond strength is weak,. With the density of microcracks increaseing, macrocrack formed, and finally cause failure of CuWCP layer, however, the Cu layer is not fracture during the whole testing.