Engineering and Applied Science Letters (EASL)

Methods to determine the environmental consequences of circular strategies may be a prerequisite for the circular economy. However, the weighting factors of the criteria groups in the international L.1023 circularity scoring standard need to be determined beforehand. No comprehensive analysis of the connection between carbon footprint based life cycle assessment (LCA) results – of the product to be evaluated and redesigned – and these weighting factors has been published. Here a method, based on lifetime reduction and Analytical Hierarchy Process (AHP), for establishing weighting factors in the L.1023 standard for circularity scoring of electronic goods (EEE), is presented. The scope of the present investigation is the life cycle of a generic EEE evaluated with the L.1023 standard, AHP and carbon emissions. Statistical hypothesis testing at the single circularity score level shows that for the EEE example, the chance of mistakenly favoring the redesigned alternative over the status quo when they are in reality indistinguishable can be as low as 0.6%.

This study focused on line integral and its applications. The study was designed to show the areas where line integral is applicable and point out the role of line integral in solving practical problems. The study found out that space curves, and the concepts of scalar and vector fields are basic concepts to deal line integral. Also, the study found out that line integral is used to calculate mass, center of mass and moments of inertia of a wire, work done by a force on an object moving in a vector field, magnetic field around a conduct, voltage generated in a loop, length of a curve, area of a region bounded by a closed curve, and volume of a solid formed by rotating a closed curve about the \(x-\)axis.

Enhancement of heat and mass transfer heat over rotating plates in industrial processes is a major area of research recently due to several attempts to find cost-effective means. In this study, the flow of Williamson fluid is considered because of its ability to exhibit pseudo-plastic and shear-thinning properties. A theoretical analysis of the effect of Coriolis force and the angle inclination on the magnetohydrodynamic flow of Williamson fluid is considered. The flow is modelled by including Coriolis force and angle of inclination in the Navier-Stokes equation. By adopting a suitable similarity transformation, the system of governing partial differential equations is reduced to a system of ordinary differential equations which are solved using bvp4c solver in MATLAB. The simulations are depicted as graphs and it is found that velocity increases with increasing Coriolis force while it decreases as the magnetic field strength and inclination angle increases. Also, the local skin friction reduces as the rotation increases. Hence, to boost heat and mass transfer in the flow of fluid over a rotating inclined plate in a magnetic field, it is recommended that rotation should be increased and magnetic field strength should be reduced.

In this paper, by using \(t\)-norms, we introduce fuzzy subalgebras and fuzzy \(d\)-ideals of \(d\)-algebra and investigate some properties of them. Moreover, we define the cartesian product and intersection of fuzzy subalgebras and fuzzy \(d\)-ideals of \(d\)-algebra. Finally, by homomorphisms of \(d\)-algebras, we consider the image and pre-image of them.

Water scarcity comes with its attendant socio-economic effects. This paper evaluated the potential water supply and sanitation facilities in Dagbolu-Nigeria to boost economy. Facilities survey was carried out for the study including information from water, sanitation and health institutions across the State. GIS approach was used to depict the groundwater recharge potential of the study area.15.3% of the populace have access to potable water while 32.5% have access to good sanitation. Water-related diseases in the area are preponderantly malaria (81.2%), diarrhoea (8.41%), typhoid fever (3.40%), dysentery (3.22%) and cholera (2.76%). Annual loss due to unproductive downtime sickness in the Nigeria is estimated to be N 414,763,442,768:00. Improve management through effective policies of water resources leading to good water supply, hygiene and sanitation will enhance development or our underdeveloped countries.

Wastewater discharged by dye manufacturing and textile finishing industries has become an environmental concern. The textile dyeing plants utilize a variety of synthetic dyes and dump massive amounts of dyeing effluent because the uptake of these dyes by fabrics is very low. The plant’s photosynthetic activity is significantly harmed by this highly colored textile dyeing effluent, impairs aquatic life because of its low light penetration and oxygen consumption. Owing to the presence of heavy metallic materials and chlorine in synthetic dyes, it could also be harmful to some aquatic creatures. Therefore, these textile wastewaters need to be treated before their discharge. Various techniques for dealing with textile dyeing effluent have been discussed in this paper. Treatment techniques presented in this study include oxidation methods, physical methods, and biological methods. Also, the paper is prepared to compile all the updated data on textile dyeing effluents’ characterization and their impact on the environment from various journals and websites and some from personal communication with some factories. Since an extensive range of synthetic dyes, namely, azo dye, vat dye, reactive dye, disperse dye, is widely used in the textile industry, some of the dyeing effluents’ physicochemical parameters surpassed their standard limits. Hence, these days, the proper monitoring and corrective steps such as the elimination process have become the most thoughtful tasks globally, particularly the developing and transition economies. It is crucial to take immediate action to minimize environmental emissions due to the discharge of untreated textile dye waste.

In the presented work we applied three machine learning techniques to forecast and predict COVID-19 cases, deaths ad recoveries numbers in Algeria for the next six months using data from February 25th, 2020 to April 26th , 2021. These models are represented by the Gaussian process regression (GPR), the support vector machine (SVM) and the decision tree (DT). The plotting results and parameters evaluation pointed out that the Gaussian Process Regression (GPR) has the best performance. Prediction with this model showed that the number of cases, deaths and recoveries will increase in the next months Algeria recording a peak in the month of August and the curve will tend to decrease later.

This paper presents the spectral reflectance of thermally evaporated ZnS/Ag nanostructures. The coating of ZnS/Ag nanostructures was performed in two steps while varying the film thickness and deposition angle. Silver metal wire (99.99% purity) was heated under vacuum at a pressure of \(2.5 \times 10^{-5}\) mBars and deposited on glass slide substrates in the diffusion pump microprocessor vacuum coater (Edwards AUTO 306). Pieces of zinc sulphide (99.99% purity) were heated and deposited to the glass slides previously coated with silver to form the ZnS/Ag/glass composite. The optical reflectance of the samples was studied by the UV/Vis/NIR spectrometer (Perkin Elmer Lambda 19) with UV-WinLab software. The reflectance was measured at angles of incidence between \(15^o\) and \(75^o\). Spectrophotometric studies showed that reflectance decreased with decrease in film thickness and decreased with increase in deposition angle of silver nanoparticles. The reflectance of ZnS/Ag nanostructures decreased with increase in deposition angle of zinc sulphide.

This paper discusses a gallery of useful results in connection with integrating factors that are often left as problems for discovery learning and are generally not taught in typical Ordinary Differential Equations courses. Most often than not the approach earlier writers employ is to give a possible form for an integrating factor that may results in an integrating curve without practical prove as far as the subject matter is concerned. In this write-up, an attempt is made by solving the resulting partial differential equation emanating from an underlining general differential equation of a non-exact form, by the use of the ratio theorem to establish various intricate possibilities of integrating factors that are seldom and often relegated to the background, even though they may be equally be applied as a function of a unitary variable or a linear combination of both the dependent and independent variables under certain conditions. Granted an integrating factor is found and such a function applied, the benefit is enormous especially the non-exact differential equation reduces into a known type which may be identified as exact, homogeneous, and or separable that yields a solution.

Green buildings are supposed to provide a sustainable solution for energy usage, but their low performance raised some questions in the literature. The researchers determine that occupants are the key factor for this energy deficiency. In the last two decades, a stream of research focuses on the greening of occupants, but a synthesis of findings and results are absent in the literature. In this study, we reviewed the literature on green buildings and occupants. Based on the findings we classified four classes. The first class consists of green occupants and green buildings, which is the ideal solution for high-energy efficiency. The second class is of brown occupants and green buildings and is the prime reason behind outperformed green buildings and yields negative-medium level efficiency. The third class comprises green occupants and brown buildings and yields positive-medium level efficiency, which helps to start the journey towards sustainability. The fourth class is the combination of brown buildings and brown occupants and has the lowest efficiency and worst impact on the environment throughout the lifecycle. Further, we link these classes with the energy-saving efficiency of buildings and finally recommended an efficient solution for second and third world countries. The study contributes to green building literature and packed with managerial implications to gain the maximum benefits of green buildings.