Band 9, Heft 1

Rapid development in technology provides an emerging growth based on innovation, invention, and diffusion, where the diffusion of resources stands with the proper disposal of wastes, due to the over-utilization of resources, growing population growth, and migration increases the accumulation of wastes especially, in Indian cities. Therefore, managing the wastes effectively is a raising challenge in the metropolitan cities of India, where the continuous monitoring of the wastes and disposal needs to be initiated. In this research, an internet-of-things-based smart waste management system in smart cities (IoT-SWMS) is focused on proposing an optimal path selection protocol that facilitates the continuous monitoring and disposal of wastes. The proposed optimal path selection protocol named Seline trustworthy optimization developed to determine the optimal routing path in IoT network renders the faster communication of the collected data regarding the level of the dustbins, which is disposed properly at the right time. The analysis of the proposed Seline trustworthy optimization-based IoT network for SWMS is performed based on the performance measures, such as delay, throughput, energy, and Packet Delivery Ratio (PDR) in comparison with the traditional methods. The proposed methodology yields the maximal PDR of 99%, a minimum delay of 0.11 s, and a maximal throughput of 38,400 kbps.

In the present work, vibration control of a simply supported plate with line type and cross type piezoelectric (PZT) patches are investigated with and without actuation voltage. The plate is modeled under the assumption of Kirchhoff’s Plate theory. The mass of PZT patches remain constant in all cases. In case of actuation, applied voltage considered are 1, 2 and 3 mV. The external excitation to the plate is in the form of harmonically varying point load of 1 mN. It is noticed that cross type PZT patch is more effective in deflection suppression of plate than that of line type PZT patch at 3 mV of actuation at patch thickness of 0.75 μm. Suppression of central deflection of plate for line type and cross type PZT patches are obtained in different frequency bands of (175–185 Hz) and (870–880 Hz) respectively.

The paper presents a technical and economic analysis for two energy systems (conventional and renewable) with grid connection. The investigation was carried out using an experimental measurement for the desired load and weather data (solar irradiance and ambient temperature), were 5.1 kWh the daily energy consumption as measured and 4.6 kWh/m 2 /day the annual average of the solar irradiance. The simulation process was done by using MATLAB and HOMER software at a 1 min time step resolution. The economic optimization objective presented for two energy system scenarios (i) photovoltaic/grid and (ii) diesel/grid, takes into account the economic aspects and component prices based on the Iraqi market and regulations. The diesel generator, very popular in rural areas, is designed to work during the same period as the photovoltaic system (only during day hours). The yearly operating hours were recorded at 4380 h/year, and energy generation was approx. 2349 kWh/year while fuel consumption was 1826 L/year. The results showed that the photovoltaic system in scenario (i) can generate about 7895 kWh, and for the diesel generator in scenario (ii), it can generate approximately 2346 kWh. Furthermore, for scenario (i) the levelized net present cost is $1079 and the cost of energy is about $0.035/kWh, while for scenario (ii) the levelized net present cost is $12,287 and the cost of energy is $0.598/kWh. The use of solar energy is highly recommended compared to diesel generators due to the lowest cost and delivery of energy to the grid. Furthermore, it can capture carbon dioxide by about 5295 kg/year.

Electricity is the most sought after resource in this world and is crucial for the development of any community. The power system structure has been changing according to the evolving scientific technologies. A novel concept in this direction is a Microgrid (MG) which is a small power system having generation and distribution with negligible presence of transmission. A MG can operate in off-grid (standalone) or grid-connected mode. The objective of this study is to perform techno-economic analysis and to design a MG model for the purpose of rural electrification. The region being considered has different resources which are capable of providing reliable supply to the load. The proposed model is compared economically with the option of grid extension. The study considers power system reliability and economic feasibility as the primary objectives for MG modelling. The village of Jarre which is located in the eastern part of Ethiopian, Somali region, is selected for this study. Particle Swarm Optimization is implemented for obtaining the most economic and reliable MG having Hybrid Renewable Energy Sources (HRES). The simulation is performed using MATLAB and Homer.

The Triboelectric nanogenerators (TENGs) are Fabricated by contact between two surfaces of different materials and convert of electric loads between them. In such structures, the two contacting layers should be radically different in terms of their electric property so that one of the layers could induce positive electrical charge while the other induces a negative charge. The application of force on and friction between the two layers induce positive and negative charges. Through the electrodes in external load, the electrical charges flow as electric current. In the present study, TEGN structures fabricated of polyethylene terephthalate polymers (PET) act as electron acceptor while Polyamide (KAPTON) and polydimethylsiloxane (PDMS) act as electron donator. The resulting outputs are compared consequently. Considering the fact that the two materials are relatively identical in terms of electron donation as they are in contact with PET, the generators fabricated of KAPTON could generate 400% more power under identical conditions. Therefore, one may conclude that KAPTON could be more suitable for development of self-power system as they are more available and more environmentally compatible.

An aerodynamic analysis is presented in the current work, which estimates the separation distance between the balloon and the turbine in an airborne wind energy system (AWES). The stability of the structure of AWES depends on the aerodynamic interaction between the turbine and the balloon. A minimum gap must be maintained between the balloon and the wind turbine to reduce the interaction between the balloon and the turbine assembly. Three cases of AWES have been studied with a separation gap of 5 m, 10 m, and 16 m to estimate the minimum distance of separation between the balloon and the turbine. The aerodynamic interaction details suggest that a minimum distance of 13 m needs to be maintained between the turbine and the balloon to avoid the interaction between the balloon and turbine. Steady-state simulations of the rotor are run for various wind conditions to evaluate the efficiency of the duct-mounted configuration. The ducted turbine configuration saw a 7.4% increase in torque than the inducted turbine for a wind speed of 5 m s −1 . A torque increase of 17.85% was observed when the separation distance was increased to 16 m from earlier 10 m.

The increase in fuel prices, along with the lack of petroleum supplies, has led researchers to seek out alternative fuels. In recent years, the concept of transforming waste into a productive source of energy has gained attention. Several forms of agricultural products, chemical reactant, and treated blends have been studied by scientists all over the world over the past few decades. The work’s goal is to determine the effectiveness with using treated transformer oil (TTO) as diesel engine fuel, thus minimizing the environmental issues created by its discharge into open space. This study also aims to capitalise used transformer oil as a renewable fuel source into compression ignition engine, since using waste oils decreases the cost of fuel. The characterization (aniline point, calorific value, density, diesel index, flash point, kinematic viscosity) of treated transformer oil (TTO) was determined and blended with diesel in the proportion of 10% (TTO10), 20% (TTO20), 25% (TTO25), 30% (TTO30), and 40% (TTO40) treated transformer oil. The outcomes are evaluated in comparison to the same diesel engine’s operation. According to the findings of the study, blends of treated transformer oil and diesel fuel may be a best choice for diesel engines since they have the same calorific value as diesel fuel. The brake thermal efficiency of blends containing up to 20% TTO is greater compared to diesel fuel. It lowers as a proportion of treated transformer oil increases and increases as the load increases. Furthermore, when the fraction of TTO in blends grows, brake specific fuel economy (BSFC) declines with load.

It is proposed to tune linear electromagnetic vibration-based energy harvesters so that they will achieve an optimum case regardless of the base amplitude or excitation frequency of the environment. The author designed the optimum coil and load parameters as well as the optimum acceleration amplitude and vibration frequency of the magnet for known values of three mechanical parameters (spring constant, mass, and mechanical damping coefficient) so that the optimum parameters will remain constant upon switching. As the vibration frequency of the magnet deviates from the optimal value, the switch turns on and off to compensate for the deviation so that the maximum power entering the electrical domain does not change. The deviation is limited to frequency or base amplitude acceleration. Other optimum parameters are fixed values. They are designed so that they can handle the maximum power that is delivered to the electrical domain.

The study evaluates the visibility of solar photovoltaic power plant construction for electricity generation based on a 20 MW capacity. The assessment was performed for four main cities in Iraq by using hourly experimental weather data (solar irradiance, wind speed, and ambient temperature). The experimental data was measured for the period from 1st January to 31st December of the year 2019, where the simulation process was performed at a 1 h time step resolution at the same resolution as the experimental data. There are two positionings considered for solar photovoltaic modules: (i) annual optimum tilt angle and (ii) two-axis tracking system. The effect of the ambient temperature and wind on the overall system energy generated was taken into consideration. The study is targeted at evaluating the potential solar energy in Iraq and the viability of electricity generation using a 20 MW solar photovoltaic power plant. The results showed that the overall performance of the suggested power plant capacity is highly dependent on the solar irradiance intensity and the ambient temperature with wind speed. The current 20 MW solar photovoltaic power plant capacity shows the highest energy that can be generated in the mid-western region and the lowest in the northeast regions. The greatest influence of the ambient temperature on the energy genrated by power plants is observed in the southern regions.

Photovoltaic (PV) systems have paved their way into general households due to their high efficiency, low deployment cost and huge power savings. These advantages combined with Government incentives further assist in wide-scale adoptability of the solar powered systems. PV systems generate direct current (DC) outputs, which needs to be converted into alternating current (AC) via inverters. The efficiency of inverter design decides the overall efficiency of the PV system, which allows effective utilization of the solar power for feeding to grid or for local usage. In order to design effective inverter models, a large number of electrical configurations are designed by researchers over the years. These include, stand-alone inverters, grid-tie inverters, battery backup inverters and hybrid inverters, each of which are further divided into multiple sub-categories. Each of these sub-categories have a different application, for instance, string-converters are used for moderate power applications up-to 150k W, while central converters are used for high power applications above 80k W, etc. Apart from power capabilities, these designs vary in terms of efficiency of conversion, usability, cost, etc. Due to so many parametric variations, effective selection of these converters for a given PV application becomes ambiguous. In order to reduce this ambiguity, the underlying text statistically evaluates performance of some of the most efficient PV converter models, and compares them on the basis of power capabilities, accuracy of conversion, converter used, control model used, etc. This review will assist researchers and system designers to select the best suited models for their given applications, and thus reduce the time needed for efficient PV inverter system design. This text also recommends future research which can be adopted for improving efficiency of these systems.