Performances of metal oxides supported in monolith for combined SO2/NOx removal from flue gas

The emission of acid gases such SO2 and NOx have detrimental effects on human beings and the environment hence, removing them from flue gas in a dry adsorption process is desirable. In this work, carbon monolith was synthesized with various metals consisting of CeO2, Co3O4, V2O5, and CuO by deposition precipitation, hydrothermal and wet pore volume impregnation synthesis techniques. The fixed bed adsorption activity test was carried out with flue gas production by coal burning. Furthermore, the breakthrough curves of the adsorbents were investigated where the adsorbent developed via hydrothermal technique with Co3O4 metal oxide termed as HM-Co3O4 /CM displayed higher adsorption capacity for both SO2 (103.9 mg/g) and NOx and (106.6 mg/g). The Langmuir model can best describe the experimental data based on the correlation coefficient and separation factor results. These results implied that the developed adsorbent can be potentially used in the industry for flue gas cleaning

Comparative Study of Maximum Power Point Tracking with a Modified DC DC Converter

Maximum power points are used to find the voltages and currents at which a photovoltaic (PV) panel should operate to obtain maximum power. In order to deliver highest power, an efficient DC DC converter and a reliable tracking algorithm are used. There is also the need to continuously find the maximum power under any environmental conditions at all times. This research is intended to study a comparative performance of maximum power point (MPP) which is presented under uniform irradiance condition. The algorithm employed is an improved cuckoo search algorithm and the DC-DC Converter( switched mode power supply) has been modified by including a synchronous rectifier connected to a load, the performance of the system is validated using MATLAB/Simulink and practical implementation for this work. A comparison of the MATLAB Simulation with the practical implementation of MPP is presented using maximum power and percentage tracking efficiency as performance metric. From the MATLAB results obtained, maximum extracted power is 26.81W and the hardware implementation gives a maximum power of 28.71W. Tracking efficiency improves by 6.62%. The results show the practical MPP gives a better maximum power, which consequently improves the Photovoltaic systems efficiency and conversely mitigates the power consumption and the cost of the system than the simulation result obtained in MATLAB

Position and Trajectory Tracking Control for the Ball and Plate System using Mixed Sensitivity Problem

This paper presents the position and trajectory tracking control scheme for the ball and plate system (BPS) using the double feedback loop structure (a loop within a loop) for effective control of the system. The inner loop was designed using linear algebraic method by solving a set of Diophantine equations. The outer inner loop was designed using   sensitivity approach. Simulation results showed that the plate was stabilized at 0.3546 seconds, and the ball was able to settle at 1.7087 seconds, when given a circular trajectory of radius 0.4 m with an angular frequency of 1.57 rad/sec, with a trajectory tracking error of 0.0095 m, which shows that the controllers have adaptability, strong robustness and control performance for the ball and plate system.           

An Election Energy Threshold Based Multi-Hop Routing Protocol in a Grid-Clustered Wireless Sensor Network

Owing to the limited energy of sensor nodes (SNs) in a wireless sensor network (WSN), it is important to reduce and balance the energy consumption of the SNs in order to extend the WSN lifetime. Clustering mechanism is a highly efficient and effective mechanism for minimizing the amount of energy that SNs consume during the transmission of data packets. In this paper, an election energy threshold based multi-hop routing protocol (mEEMRP) is presented. In order to minimize energy consumption, this routing protocol uses grid clustering, where the network field is divided into grid clusters. SNs in each grid cluster select a cluster head (CH) based on a weight factor that takes the node location, node’s residual energy (RE) as well as the node’s distance from the base station into consideration. An energy efficient multi-hop routing algorithm is adopted during the transmission of data packets from the cluster heads (CHs) to the base station (BS). This multi-hop routing algorithm uses an election energy threshold value, T­nhCH that takes into consideration the RE of CHs as well as the distance between CHs. Simulation results show a 1.77% and 10.65% improvement in terms of network lifetime for two network field scenarios over Energy Efficient Multi-hop Routing Protocol (EEMRP)

A Review on Critical Data Transmission in Wireless Body Area Networks

Wireless body area networks (WBANs) assemble multiple transceiver nodes in, on, or around a patient's body to transmit physiological signals to the sink node and further send it to the medical personnel via a medical server. WBANs a sensor network that is characterized as energy-dependent. Due to this finite nature, the deployment of intelligent utilization is needed. Quality of service (QoS) is another area that needs rapt attention to receive exactly what was sent from the source node to the destination node and throughput. Critical data transmission is characterized by abnormal data status that requires an urgent response from the medical personnel without delay to save the patient's life. In this review article, we propose a review of critical data transmission in wireless body area networks. However, most past articles in this line focus more on energy-efficient, security and privacy, quality of the links, throughput, network maximization, and so on. None of them looks into the direction of transmitting critical data directly to the sink node without multi-hopping of the physiological signals between intermediate nodes, which wastes the time of transmission to save patient life. This disparity between these scholars motivates us to fill the gap between them. This review article briefly discussed the state-of-the-art critical data transmission in WBANs alongside the WBANs architecture and implementation. Furthermore, a pragmatic approach to determining the threshold's degree of critical data index sensed during transmission was also considered

Analysis of the Impact of Relative Humidity and Mineral Nuclei Mode Aerosols Particle Concentration on the Visibility of Desert Aerosols

This paper presents the results of the Analysis of the Impact of relative humidity and water-soluble aerosol particle concentrations on the visibility and particle size distribution of desert aerosols based on microphysical properties of desert aerosols. The microphysical properties (the extinction coefficients, volume mix ratios, dry mode radii and wet mode radii) were extracted from Optical Properties of Aerosols and Clouds (OPAC 4.0) at eight relative humidities (00 to 99%RH) and at the spectral range of 0.4-0.8 mm. the concentrations of mineral nuclie component (MINN) were varied to obtain five different models. The angstrom exponent (a), the turbidity (b), the curvature (a2), humidification factor (g), the mean exponent of aerosol growth curve (µ) and the mean exponent of aerosol size distributions (n) were determined from the regression analysis of some standard equations. It was observed that the values of (a) are less than 1 throughout the 5 models which signifies the dominance of coarse mode particles over fine mode particles. It was observed that the curvature (a2) has both monomodal and bimodal types of distributions all through the 5 models and this signifies the dominance of coarse mode particles with some traces of fine mode particles. The visibility was observed to decrease with the increase in RH and increased with wavelength. The analysis further found that there is an inverse power law relationship between humidification factor, the mean exponent of the aerosol size distribution with the mean exponent of the aerosol growth curve (as the magnitude of (µ) decreases across the five models, the magnitudes of (g) and (n) increase, but the magnitude of both (g) and (n) increases for a given (µ) across the individual models). The mean exponent of aerosol size distribution (µ) being less than 3 indicate hazy condition of the desert atmosphere

Performances of Metal Oxides Supported in Monolith for Combined SO2/NOx removal from Flue Gas

The emission of acid gases such SO2 and NOx have detrimental effects on human beings and the environment hence, removing them from flue gas in a dry adsorption process is desirable. In this work, carbon monolith was synthesized with various metals consisting of CeO2, Co3O4, V2O5, and CuO by deposition precipitation, hydrothermal and wet pore volume impregnation synthesis techniques. The fixed bed adsorption activity test was carried out with flue gas production by coal burning. Furthermore, the breakthrough curves of the adsorbents were investigated where the adsorbent developed via hydrothermal technique with Co3O4 metal oxide termed as HM-Co3O4 /CM displayed higher adsorption capacity for both SO2 (103.9 mg/g) and NOx and (106.6 mg/g). The Langmuir model can best describe the experimental data based on the correlation coefficient and separation factor results. These results implied that the developed adsorbent can be potentially used in the industry for flue gas cleaning. &nbsp

Post occupancy evaluation sustainability assessment framework for commercial office buildings

Researchers have studied the concept of building performance and their evaluation over the years. The growth and use of performance assessment methods for existing buildings have contributed to sustainability in various stages of building performance especially in determining the occupant's needs and expectations of sustainability in office buildings. Assessment tools have been developed with different evaluation criteria based on the condition to suit the characteristics of the countries for which the tools were designed, hence applying sustainability assessment tool in rating existing building can be effective in optimized decision making to use them. This study explores the process of developing assessment criteria to assess sustainability in buildings. One of the primary and main steps in each criterion is arranging the assessment items, and then the assessment criteria are made based on relevant performance criteria and parameters

An Election Energy Threshold Based Multi-Hop Routing Protocol in a Grid-Clustered Wireless Sensor Network

Owing to the limited energy of sensor nodes (SNs) in a wireless sensor network (WSN), it is important to reduce and balance the energy consumption of the SNs in order to extend the WSN lifetime. Clustering mechanism is a highly efficient and effective mechanism for minimizing the amount of energy that SNs consume during the transmission of data packets. In this paper, an election energy threshold based multi-hop routing protocol (mEEMRP) is presented. In order to minimize energy consumption, this routing protocol uses grid clustering, where the network field is divided into grid clusters. SNs in each grid cluster select a cluster head (CH) based on a weight factor that takes the node location, node’s residual energy (RE) as well as the node’s distance from the base station into consideration. An energy efficient multi-hop routing algorithm is adopted during the transmission of data packets from the cluster heads (CHs) to the base station (BS). This multi-hop routing algorithm uses an election energy threshold value, T­nhCH that takes into consideration the RE of CHs as well as the distance between CHs. Simulation results show a 1.77% and 10.65% improvement in terms of network lifetime for two network field scenarios over Energy Efficient Multi-hop Routing Protocol (EEMRP)

Implementation of inkjet-printed 3 dB coupler with equal power division and 45° output phase difference

Implementation of a 3 dB coupler with flexible phase difference was presented in this paper. The coupler has equal power division and output phase difference of 45° as against the conventional coupler. It has advantage in many applications that require phase delay like phased antenna array, and beamforming network without necessarily requiring additional phase shifters. It was designed and implemented using the instant inkjet printing technique on a transparent Polyethylene terephthalate (PET) substrate specially coated with resin. The coupler's response shows very good return loss and isolation of −28 and −48 dB, respectively. A bandwidth of 31.33% was achieved around the center frequency. However, an output phase difference of 45° was recorded with a slight phase variation of about ±1° within the specified bandwidth