Progress in the experimental and computational methods of work function evaluation of materials: A review.

The work function, which determines the behaviour of electrons in a material, remains a crucial factor in surface science to understand the corrosion rates and interfacial engineering in making photosensitive and electron-emitting devices. The present article reviews the various experimental methods and theoretical models employed for work function measurement along with their merits and demerits are discussed. Reports from the existing methods of work function measurements that Kelvin probe force microscopy (KPFM) is the most suitable measurement technique over other experimental methods. It has been observed from the literature that the computational methods that are capable of predicting the work functions of different metals have a higher computational cost. However, the stabilized Jellium model (SJM) has the potential to predict the work function of transition metals, simple metals, rare-earth metals and inner transition metals. The metallic plasma model (MPM) can predict polycrystalline metals, while the density functional theory (DFT) is a versatile tool for predicting the lowest and highest work function of the material with higher computational cost. The high-throughput density functional theory and machine learning (HTDFTML) tools are suitable for predicting the lowest and highest work functions of extreme material surfaces with cheaper computational cost. The combined Bayesian machine learning and first principle (CBMLFP) is suitable for predicting the lowest and highest work functions of the materials with a very low computational cost. Conclusively, HTDFTML and CBMLFP should be used to explore the work functions and surface energy in complex materials.

Dataset on thermodynamics performance analysis and optimization of a reheat - regenerative steam turbine power plant with feed water heaters.

Steam power plants have a considerable potential to meet the growing energy demand, but its dependence on conventional fossil fuels has hampered its viability. One of the ways to minimize fuel consumption and upgrade the performance of a Rankine cycle is by incorporating closed feedwater heaters(FWHs). The datasets contained in this paper are thermodynamic performance analysis carried out on reheat - regenerative steam power plant with FWHs using CyclePad V2.0 software. The thermodynamic performance indices assessed are thermal efficiency, network output, heat rate, fuel consumption, boiler efficiency and specific steam consumption. Result obtained show that an increase in the number of FWHs decreases the fuel consumption, heat rate, heat rejected in condenser and heat input to the cycle. This effect invariably can lead to a reduction in operating cost and environmental impacts.

Dataset on performance of solar powered agricultural produce cooling storage system under tropical conditions.

Much of the post-harvest loss of agricultural produce in developing countries is due to lack of proper storage facilities. Agricultural produce such as peppers, tomatoes and fruits are highly perishable in nature; thus, maintaining the optimal air conditions inside the storage cabinet helps extending their shelf lives. The datasets contained in this paper are performance test carried out on agricultural produce cooling storage system under tropical conditions for various cooling pads (jute fibre) thickness and under no load and load conditions. The parameters recorded under these conditions include wet and dry bulb temperatures, relative humidity of the surroundings, relative humidity and temperature within the cooling chamber taken consecutively for 4 days with different pad thickness and for 5 days and 8days under no load and load conditions, respectively. Results obtained show that pad thickness of 80 mm has the highest cooling efficiency of 84.7% and temperature within the cooling chamber was found dropped to 25 °C and average relative humidity of cooling chamber increased to 82.4% as compared to 64.8% for ambient condition.

A GIS - based method for assessment and mapping of noise pollution in Ota metropolis, Nigeria.

A detailed method used for assessing and mapping noise pollution levels in Ota metropolis, Nigeria using ArcGIS 10.5 Software is presented in this paper. Noise readings were measured at a time interval of 30 min for each site considered using a precision grade sound level meter. The noise map developed was based on the computed values of average equivalent noise (LAeq) for the selected locations. Results of this study show that the A weighted sound level (LAeq), the background noise level (L10) and the peak noise level (L90) vary with location and period of the day due to traffic characteristics especially traffic volume, vehicle horns, vehicle mounted speakers, and unmuffled vehicles at road Junctions, major roads, motor parks and commercial centres. Based on the U.S. Department of Housing and Urban Development (HUD) recommendations and standards, only one (1) out of the 41 locations considered is under normally acceptable situation, while 12 locations are under normally unacceptable and the noise levels of the rest locations are clearly unacceptable. Results of this study are useful as reference and guideline for future planning and regulations on noise limit to be implemented for urban areas like Ota Metropolis. •Instrumentation used in this study for the environmental noise measurements consisted of a precision-grade sound-level meter - Model 8922 RS232.•The Geographical Positioning System (GPS) device (model: Magellan eXplorist 310) was used to obtain the exact coordinates of each location where noise level readings were recorded.•ArcGIS 10.5 software was used in this study to develop noise map for Ota Metropolis.

Dataset on noise level measurement in Ota metropolis, Nigeria.

Datasets contained in this article are noise level measurement carried out at 41 different locations in Ota metropolis, Nigeria. The noise readings were measured at a time interval of 30 min for each site considered using a precision grade sound level meter. The analysis was based on the noise descriptors LAeq, L10, L90, LD, TNI and NEI. Results from the study reflects that the highest and lowest equivalent noise levels (LAeq) were recorded at commercial areas (96 dB (A)) and residential areas (52 dB (A)), respectively, the background noise level (L90) has the highest and lowest values at commercial areas (77 dB (A)) and residential areas (44 dB (A)), respectively and the peak value (L10) has the highest value and lowest value at the commercial areas (96 dB (A)) and residential areas (56 dB (A)). Based on the WHO recommendations and standards, only 2 out of the 41 locations considered are under normally acceptable situation while the noise levels of other areas are not acceptable. Noise map developed in this study provides enough information for technical controls and interim legislation against environmental noise pollution in the metropolis. Moreover, considering the noise emission standards, planning and promoting the citizens awareness about the high noise risk could help to mitigate the effect of noise in Ota, Metropolis. The noise data in this study are useful as reference and guideline for future regulations on noise limit to be implemented for urban areas in Nigeria and developing countries at large.