Study on sisal fibres as insulator in building materials

In this current era, there are some concerns of using synthetic fibres in regards to their impact on the environment since they are non-recyclable and non degradable. There are many attempts by various groups of engineers and researchers to use natural fibres in engineering applications, in the hopes of replacing synthetic fibres with natural fibres. In this project, the possibility of using natural fibres in building materials is investigated in terms of their compression strength and heat conductivity. Sisal fibres are selected as reinforcement for gypsum walls for the application in industrial and commercial buildings. To gain high interfacial adhesion of the sisal fibres with gypsum, a study on the optimum chemical treatment concentration of NaOH (0-10 %) is considered. To study the heat conductivity of the composites, a newly designed heat conductivity test setup is developed to study the influence of different volume fractions of glass and sisal fibres on the conductivity of gypsum. In addition, compressive test was performed for the selected materials. Failure mechanisms of the samples after compressive testing are examined with the aid of the scanning electron microscopy (SEM). The results revealed that the alkalization on the sisal fibres have provided different levels of interfacial adhesion in the composites which were pronounced on the surface topography of the fibres. Based on this observation and supported by other literatures, 6% NaOH was selected as the optimal concentration for composite fabrication. From the compressive test, it was observed that the addition of fibres to the gypsum matrix improves the compressive strength and resulted in reduced brittleness. For sisal fibre-gypsum composite, the optimum fibre content is at 25 vol.% while for glass fibre-gypsum composite, the optimum fibre content is at 30 vol.%. The thermal conductivity resulted showed that pure gypsum was found to have the highest thermal conductivity. The thermal conductivity of the composites decrease with the increment of fibre volume fraction for both synthetic and natural addition of the fibres. Sisal fibre-gypsum composites performs slightly better at insulating heat as compared to glass fibre-gypsum composites possibly due to its porous nature, as heat transfer is impeded by the presence of air voids

NeTO:Neural Reconstruction of Transparent Objects with Self-Occlusion Aware Refraction-Tracing

We present a novel method, called NeTO, for capturing 3D geometry of solid transparent objects from 2D images via volume rendering. Reconstructing transparent objects is a very challenging task, which is ill-suited for general-purpose reconstruction techniques due to the specular light transport phenomena. Although existing refraction-tracing based methods, designed specially for this task, achieve impressive results, they still suffer from unstable optimization and loss of fine details, since the explicit surface representation they adopted is difficult to be optimized, and the self-occlusion problem is ignored for refraction-tracing. In this paper, we propose to leverage implicit Signed Distance Function (SDF) as surface representation, and optimize the SDF field via volume rendering with a self-occlusion aware refractive ray tracing. The implicit representation enables our method to be capable of reconstructing high-quality reconstruction even with a limited set of images, and the self-occlusion aware strategy makes it possible for our method to accurately reconstruct the self-occluded regions. Experiments show that our method achieves faithful reconstruction results and outperforms prior works by a large margin. Visit our project page at \url{https://www.xxlong.site/NeTO/

Shadow Detection and Removal in Single-Image Using Paired Regions

A shadow appears on an area when the light from a source cannot reach the area due to obstruction by an object. The shadows are sometimes helpful for providing useful information about objects, and sometimes it degrade the quality of images or it may affect the information provide by them. Thus for the correct image interpretation it is important to detect shadow and restore the information. However, shadow causes problems in computer vision applications, such as segmentation, object detection and object counting. That’s why shadow detection and removal is a pre-processing task in many computer vision applications. So we propose a simple method to detect and remove shadows from a single image. The proposed method begins by selecting shadow image and by pre-processing method we focus only on shadow part. In image classification we distinguish between shadow and non shadow pixels. So that we able to label shadow and non shadow regions of the image. Once shadow is detected that detection results are later refined by image matting, and the shadow- free image is recovered by removing shadow region by non shadow region. Examination of a number of examples indicates that this method yields a significant improvement over previous methods

Durable and ductile double-network material for dust control

Dust generation is a world-wide issue due to its serious deleterious effects on the environment, human health and safety, and the economy. Although various dust suppression methods have been used for decades, some critical drawbacks in state-of-the-art technology still remain unsolved, such as short-lasting, ground water impact, and prone to water. This work reports a soil stabilizer based on non-toxic material and forms a ductile and durable double-network in soil, namely “D3 soil stabilizer”, which not only improves soil mechanical toughness of surface soil but also suppresses dust generation. A copolymer comprising hydrophilic and hydrophobic components combined with enzyme-induced carbonate precipitation is utilized as an in-situ gelation binder to soil particle. The tunable hydrophobic-to-hydrophilic component ratio minimizes undesirable soil matrix expansion and mechanical strength loss upon experiencing wet-dry processes, while still retains good water affinity. We further demonstrated controllable treatment depth by fine-tuning precursor composition, which is essential to minimize environmental impact. The double-network morphology with carbonate precipitate embedded uniformly in polymer matrix is observed via microscopic imaging. The nature of outstanding ductility, high durability against water, and good long-term stability were supported by systematic unconfined compressive strength (UCS) measurements on treated soil, which show strong inter-particles binding, good retention of peak strength, increased strain at peak strength, and increased toughness after soil samples have experienced wet-dry processes

Overburden Dump Slope Stability: A Case Study At Coal Mine

Slope stability of overburden dumps plays as integral part of opencast mine project throughout the operation process. Waste dumps always have steep angled slopes as the waste has been tipped over from the top of the dump in a continuous and progressive manner. For new landfill it is often desirable to design steep slopes as it can accommodate the maximum amount of waste possible. The heavy machinery implanted for the extraction and transportation of wastes in the opencast mine whose management is of prime importance. The problems relating to overburden dump slope stability is catching attention for safe working in adverse natural constraints. This paper examines the influence of various parameters such as slope height, slope inclination, interfacial shearing resistance on the dump deposit. The analysis cover analysis of various sections of the waste dumps from the mine including material properties, strength values, bench height and angle. The evaluation of slope stability analyses in geotechnical analyses in geotechnical engineering has followed closely developments in soil and rock mechanics as a whole. Most of the design methods are purely based on field experience, followed by sound engineering judgment. During the last few decades, the concepts of slope stability analysis have emerged within the domain of rock and geotechnical engineering to address the problems of design and stability of dump slopes