Particle-scale numerical study on screening processes

The present study aimed to increase the understanding of the industrial screening process by using the discrete element method simulation (DEM) and machine learning modelling. Thus, the study focused on understanding the fundamentals of the complicated screening processes by investigating the process model with different controlling factors through particle-scale analysis. The particle-scale analysis was also linked to several macroscopic models and screening processes such as percolation of particles under vibration, the local passing of particles from the screen, choking of screening, non-spherical shaped particles contact detection and packing and machine learning modelling. The computational and theoretical analyses as well as machine leaning helped to clarify the use of particle-scale analysis and screening processes in several areas. The outcomes of this thesis include: (i) the percolation of particles under vibration and the machine learning modelling of percolation velocity to predict the size ratio threshold; (ii) a better understanding of screening process based on local passing of inclined and multi-deck screen and physics informed machine learning modelling to predict the particles passing; (iii) a logical model to predict the choking judgement of screen while combining the numerical results and machine learning and (iv) a novel contact force model for non-spherical particles by Fourier transformation and packing. The research in this thesis is useful for the fundamental understanding of the effect of particles’ contact force, operational conditions, particle properties, percolation and sieving on the screening process. Moreover, the novel process models based on artificial intelligence modelling, DEM simulation, and physics laws can help the design, control and optimisation of screening processes

Isolation and screening of actinomycetes from Sundarbans soil for antibacterial activity

A total of 55 actinomycetes isolates from soil sample of Karanjal region in Sundarbans were characterized for morphological identification and antimicrobial activity. Four general such as Actinomyces, Nocardia, Streptomyces and Micromonospora with total numbers of isolates were 27, 14, 11 and 3, respectively, were identified from the sample. Twenty actinomycetes isolates produced antibiotic against one or more gram-negative pathogenic bacteria such as Shigella boydii, Shigella flexneri-AN-31153, Shigella sonnei, Pseudomonas, Shigella dysenterriae type-1, Vibrio cholerae-0139, Salmonella typhi-Ao-12014, Plesiomonas, Hafnia spp., Vibrio cholerae-OGET, and Escherichia coli-186LT. The study indicated that Sundarbans’ soil had diverse group of actinomycetes and three of the tested isolates had a broader spectrum antibacterial activity which showed potential as a source of antibiotics for pharmaceutical interest

Effect of chemical treatments on physico-chemical properties of fibres from banana fruit and bunch stems

Fibres have been extracted from fruit and bunch stems of banana plant by water retting and evaluated in terms of their performance characteristics. Banana bunch stem fibres have been found to be superior in terms of fineness, initial modulus and breaking strength, whereas elongation ratio shows an inverse trend. Thus, they have been further treated by bleaching and alkalization. Among the treated fibres, the bleached fibres show the highest initial modulus, breaking tenacity, and the lowest elongation. Alkalization results in increased breaking elongation and decreased initial modulus, whiteness and water absorption. The bunch stem fibres present higher water absorptive capacity and lower whiteness compared to that of fruit stem fibres. The characteristics of these unconventional fibres have been found to be comparable to natural fibres traditionally used in textiles. The ranges for properties of the studied banana fruit and bunch stem fibres in general can be given as: linear density 12.71-20.38 tex, initial moduli 168 -326 cN/tex, breaking tenacity 9.89-13.3 cN/tex, breaking elongation 4.42-16.4%, and moisture content 11.6-15.8%

Enhancing the Properties of Marl Soils for Effective Construction in Saudi Arabian Region

Marl, containing primarily carbonate (CaCO3) and clays of different percentages with occasional traces of organic matter, silt or sand is usually used as bases and sub-bases for roads and highways. Marl is usually used as sub-grade layers or as a backfill in base and sub-base layers for roads and highways. This type of soil has poor strength and high water sensitivity; a drastic loss of bearing capacity may occur upon immersion.Due to its poor strength and high water sensitivity, appropriate treatment from engineering perspective is necessary before such soils are recommended for use in any construction project. Critical analysis of different stabilization techniques employed in Saudi Arabia for last 30 years has been carried to find the best technique. Mechanical and chemical treatments were found to be more economical than Drainage, dewatering and other techniques. It has been noticed that no study was done in stabilization of Marl Soil using Geo-synthetics technique Hence, it can be an alternate way for future research to improve marl.Marl, containing primarily carbonate (CaCO3) and clays of different percentages with occasional traces of organic matter, silt or sand is usually used as bases and sub-bases for roads and highways. Marl is usually used as sub-grade layers or as a backfill in base and sub-base layers for highway pavements. This type of soil has poor strength and high water sensitivity; a drastic loss of bearing capacity may occur upon immersion. Due to its poor strength and high water sensitivity, appropriate treatment from engineering perspective is necessary before such soils are recommended for use in any construction project effectively. Critical analysis of different stabilization techniques employed for enhancing the marl soil properties in Saudi Arabia for the last 30 years has been carried out to find the best engineering solution. Mechanical and chemical treatments were found to be more economical than drainage, dewatering and other techniques. It has been noticed that no study was done in stabilization of Marl Soil using Geo-synthetics technique Hence, it can be an alternate way for future research to improve marl

Effect of chemical treatments and coupling agents on the properties of unidirectional jute fiber reinforced polypropylene composite

Due to different chemical nature of jute and polypropylene, their blended composite materials often show failures behavior when applied in load bearing purposes. The aim of the research is to improve the properties of unidirectional jute fiber (JF) reinforced polypropylene (PP) composite. Unidirectional fiber composite was produced by simple hot press molding method according to weight percentage of 30wt% filler (JF), 2wt% coupling agent (compatibilizer) degraded PP (DgPP) and maleated PP (MAPP) and 68 wt% matrix (PP). To improve the interfacial interactions between the fiber and PP, the fiber was chemically modified with 10w/v% NaOH, 6w/v% dicumylperoxide (DCPO), 0.05 w/v% K2Cr2O7 and 5 w/v% H2O2 solution. The water absorption, tensile and thermal properties of raw and surface treated fibers composites were compared in particular coupling agent. It has found that the fiber treatments and addition of coupling agents, composites showed better properties. Among the composites, 10 wt/v% NaOH treated jute reinforced PP composite by using MAPP compatibilizer was presented better water absorption and mechanical properties. The positive change of the treated fiber composites was also found in case of the thermal stability that investigated by the TG, DTA and DTG tests

Mechanical, thermal and morphological studies of microfibrillated jute/PLA biocomposites

In the present study, biocomposites based on microfibrillated jute (MFJ) fibre and polylactic acid (PLA) have been prepared by solvent-assisted compression moulding techniques. The MFJ is obtained by a sequence of alkali, chlorite and acid treatments of jute fibre. The biocomposites are fabricated by loading of 10, 20 and 30 wt% of MFJ fibre into the PLA matrix. The effect of MFJ fibre loading on the mechanical, thermal, and morphological properties of the composites is also studied. Among these composites, it is observed that 10 wt% fibre-filled biocomposite shows improved tensile strength andtensile modulus compared to virgin PLA film. Similarly, storage modulus and loss modulus are also found improved for the composites. These composites exhibit higher water absorption capacity and lower thermal stability than virgin PLA. The fibre-matrix adhesion is evaluated by scanning electron microscopy. The results are attributed to the improved interfacial adhesion between MFJ and PLA matrix for 10 wt% fibre-filled biocomposites

Numerical simulation of periodic MHD casson nanofluid flow through porous stretching sheet

The perspective of this paper is to characterize a Casson type of Non-Newtonian fluid flow through heat as well as mass conduction towards a stretching surface with thermophoresis and radiation absorption impacts in association with periodic hydromagnetic effect. Here heat absorption is also integrated with the heat absorbing parameter. A time dependent fundamental set of equations, i.e. momentum, energy and concentration have been established to discuss the fluid flow system. Explicit finite difference technique is occupied here by executing a procedure in Compaq Visual Fortran 6.6a to elucidate the mathematical model of liquid flow. The stability and convergence inspection has been accomplished. It has observed that the present work converged at, Pr ≥ 0.447 indicates the value of Prandtl number and Le ≥ 0.163 indicates the value of Lewis number. Impact of useful physical parameters has been illustrated graphically on various flow fields. It has inspected that the periodic magnetic field has helped to increase the interaction of the nanoparticles in the velocity field significantly. The field has been depicted in a vibrating form which is also done newly in this work. Subsequently, the Lorentz force has also represented a great impact in the updated visualization (streamlines and isotherms) of the flow field. The respective fields appeared with more wave for the larger values of magnetic parameter. These results help to visualize a theoretical idea of the effect of modern electromagnetic induction use in industry instead of traditional energy sources. Moreover, it has a great application in lung and prostate cancer therapy

Recent advances on palm oil mill effluent (POME) pretreatment and anaerobic reactor for sustainable biogas production

Palm oil is one of the leading agricultural crops in the world, as it dominates 34% of the global vegetable oil market, with approximately 64.6*103 million kgs of production in 2017. However, along with its breakthrough, the generation of palm oil mill effluent (POME) as uncontrolled waste has become a serious matter and requires proper management to reduce its negative effects on the environment. Subsequently, the high organic content of POME makes it possible to convert waste into value-added products, such as biogas. A ratio of 0.5 for biological oxygen demand to chemical oxygen demand (BOD/COD) indicates a high possibility for biological treatment. Recently, the utilisation of POME as a cheap source for biogas production has gained an extraordinary amount of attention, and intensive research has been conducted on the upstream to downstream process. Finding the most suitable and efficient pretreatment technique and reactor configuration are vital parameters for the treatment and conversion of POME to biogas. This review describes existing pretreatment processes for POME and recommends recently manufactured high-rate anaerobic reactors as the most suitable and efficient pretreatment technique for maximising the extraction of biogas from POME

Usage of Mathematics Tools with Example in Electrical and Electronic Engineering

Usage of mathematics in different flow of electrical and electronic engineering is outstanding by everybody. In this paper, a good number of examples of applications of mathematics in electrical and electronic engineering have designed. The motivation behind this paper is to relate mathematics to electrical and electronic engineering subject. Numerous electrical and electronic engineering students think that it’s hard to tackle electrical and electronic engineering problems which require mathematics a considerable measure. It is not possible to investigation of current, voltage, electric LR and RC circuit, electromagnetic fields, designing and analyzing circuits without utilization of scientific instruments of trigonometry, Calculus, Geometry and Differential Equation