Ductility of Steel-Fibre-Reinforced Recycled Lightweight Concrete

This work examines experimentally and numerically the influence of steel fibre reinforcement on lightweight aggregate concrete (LWAC). The replacement of conventional aggregates with recycled lightweight ones has several benefits such as reducing the mass of the structure lead-ing to more economical designs (also beneficial under earthquake loading). The experimental project showed that it was possible to produce higher strength to weight ratio of LWAC com-pared to normal weight aggregate concrete (NWAC) as dry densities were approximately 700 Kg/m3 lower for identical characteristic compressive strengths between 40MPa and 30MPa. This could lead to savings in materials, construction and transportation costs making it espe-cially useful and economical for long-span and seismic-resistant structures. Conversely, LWAC is noted for its highly brittle nature due to its associated weak aggregate interlock mechanism which can be typically compensated for by increasing shear reinforcement and dowel action by means of adding higher reinforcement ratios. Nonetheless, this creates sever-al challenges in construction such as congestion of reinforcement in critical regions as well as increased dead loads which render LWAC use counterproductive. Thus, steel fibre rein-forcement emerges as a promising solution where partial or total substitution of conventional transverse reinforcement could become a possibility. This project carries out examination of the effectiveness of hooked-end steel fibre reinforcement with fibre volume fractions of Vf = 1% and Vf = 2%. The experimental investigation includes the study of direct uniaxial com-pression and tension (unique pullout test) and indirect splitting and flexural tensile tests. Moreover, a nonlinear finite element study has been carried out using ABAQUS to model the experiments using CDP. Currently, there is no international standards or design guidelines for steel fibre reinforced lightweight concrete (SFRLC). This project will help address that and lead to sustainable and innovative seismic design solutions in the future

Improvement of Unconfined Compressive Strength of Natural Organic Soil

The aim of this paper is to investigate the possible improvement of unconfined compressive strength of natural organic soil by using cement dust and fly ash. Natural organic soil with different percentage of organic content (0, 5, 10.15 and 20 %) is used. Three different percentages of cement dust and fly ash (3, 6 and 9 %) are used to improve the strength characteristics of the organic soil. The effect of curing time is investigates. The result show that unconfined compressive strength of organic soil decreased with increasing the organic content. The addition of cement dust increased the unconfined compressive strength for all percentage of organic content, while the addition of fly ash improved the strength characteristics of organic soil for samples with organic content greater than 10 %. Keywords: organic content, unconfined compressive strength, cement dust, fly ash

Nanostructural and optical properties of hierarchical ZnO grown via hydrothermal method

A simple hydrothermal method was employed to synthesize 3D hierarchical ZnO nanorods deposited on Si (100) substrate at different growth temperatures (110 and 90oC) within 3 h. The structure, mode and composition of hierarchical ZnO nanorods were investigated by XRD, FESEM and EDX spectroscopy. The polycrystalline ZnO nanostructures products were indexed as hexagonal wurtzite structured, while the morphology was urchin like ZnO nanorods with different aspect ratio of nanorods and stoichiometric. The photoluminescence (PL) properties were studied of as-grown ZnO samples dependent on various growth temperatures. The PL results after UV excitation source were shown a single broad Vis emission peak for both samples with absents of UV emission peak. The emission edge of Vis peak was exhibited blue-shift due to increase temperature growth, and that suggest enhancement in hierarchical ZnO nanorods crystallinity. Oxygen deficiency is evidence on the creation various defects types in hierarchical ZnO nanorods. It is responsible on Vis emission bands. The results demonstrate promising future for the hierarchal ZnO nanostructure which could be applied in optoelectronics and gas sensing

Spectral characteristics of normal and nutrient-deficient maize leaves

Reflectance, transmittance and absorbance spectra of normal and six types of mineral-deficient (N,P,K,S,Mg and Ca) maize (Zea mays L.) leaves were analyzed at 30 selected wavelengths along the electromagnetic spectrum from 500 to 2600 nm. Chlorophyll content and percent leaf moisture were also determined. Leaf thermograms were obtained for normal, N- and S- deficient leaves. The results of the analysis of variance showed significant differences in reflectance, transmittance and absorbance in the visible wavelengths among leaf numbers 3, 4, and 5, among the seven nutrient treatments, and among the interactions of leaves and treatments. In the reflective infrared wavelengths only treatments produced significant differences. The chlorophyll content of leaves was reduced in all deficiencies in comparison to controls. Percent moisture was increased in S-, Mg- and N- deficiencies. Positive correlation (r = 0.707) between moisture content and percent absorption at both 1450 and 1930 nm were obtained. Polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related (r = 0.894)

Multifocus Images Fusion Based On Homogenity and Edges Measures

Image fusion is one of the most important techniques in digital image processing, includes the development of software to make the integration of multiple sets of data for the same location; It is one of the new fields adopted in solve the problems of the digital image, and produce high-quality images contains on more information for the purposes of interpretation, classification, segmentation and compression, etc. In this research, there is a solution of problems faced by different digital images such as multi focus images through a simulation process using the camera to the work of the fuse of various digital images based on previously adopted fusion techniques such as arithmetic techniques (BT, CNT and MLT), statistical techniques (LMM, RVS and WT) and spatial techniques (HPFA, HFA and HFM). As these techniques have been developed and build programs using the language MATLAB (b 2010). In this work homogeneity criteria have been suggested for evaluation fused digital image's quality, especially fine details. This criterion is correlation criteria to guess homogeneity in different regions within the image by taking a number of blocks of different regions in the image and different sizes and work shifted blocks per pixel. As dependence was on traditional statistical criteria such as (mean, standard deviation, and signal to noise ratio, mutual information and spatial frequency) and compared with the suggested criteria to the work. The results showed that the evaluation process was effective and well because it took into measure the quality of the homogenous regions

COVID-19 and the effect of its infodemic on people’s wellbeing

In this research, it was used to look at social media behaviour during the pandemic and how it might have affected well-being. The WHO-5 Well-Being Index (WHO-5) score was used to do this. COVID-19-related material was sought for and disseminated through social media by those who participated in the study. This research shows how social media might affect people's well-being during this epidemic and other crisis in the future. 73 percent of the 993 participants were women, 91 percent were university graduates, and 50 percent worked in diverse occupations, with 20 percent working in health care. Participants said they got COVID-19-related news mostly via social media and messaging apps, with WhatsApp being the most popular. After authentication, the majority of participants said they shared information. Throughout the coronavirus pandemic, this research offers insight into the usage of Social Media and its influence on well-being. During catastrophes and disasters, social media behaviours may have an influence on public safety. There is also a need for global and local health authorities to better prepare for future challenges by developing policies and actions that address these difficulties. Social media activities may directly affect one's mental health, but more research is required before conclusions can be drawn

The effects of the ambient liquid medium on the ablation efficiency, size and stability of silver nanoparticles prepared by pulse laser ablation in liquid technique

Silver (Ag) nanoparticles (NPs) were synthesized by pulsed laser (Nd:YAG, 1064 nm) ablation of individual target in various solutions. The influence of deionized water (DIW), ethanol and Polyvinylpyrrolidone (PVP) as ambient medium on the fundamental aspects such as ablation efficiency, particle size and stability of Ag NPs was studied. UV-vis spectrophotometer and transmission electron microscopy (TEM) were used to study the optical characterization and morphological analysis of all the synthesized samples, respectively. Preparation in DIW was carried out as a reference sample. The experiments demonstrated that ablation efficiency and stability of NPs in ethanol medium are lowest than those prepared in PVP medium and the reference sample. PVP medium led to higher stability, lower ablation efficiency and finer average particle size compared to reference sample

Synthesis and Thermal Characterization of Copolymers Containing Amino Acids

Thee copolymers of amino acid were synthesized in two steps. First, the amino acids react with resorcinol to formation of azo monomers step. They led in a second condensation polymerization step to copolymeric materials. The structures of the copolymers were characterized by means of FT-IR and 1H-NMR spectroscopy. The thermal properties were investigated by TGA and DTG. Keywords: copolymers, amino acid, thermal properties, azo compoun