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This study presents an improved correlation for predicting heat transfer coefficients for condensation inside smooth macro-tubes. Experimental data was obtained for various fluids, including R12, R1234yf, R1234ze, R134a, R22, R263fa, R245a, R32, R404a, R410a, and R600a. Tube diameters ranging from 3 to 14 mm, mass fluxes ranging from 50 to 1400 kg/m2s, and a vapor quality between 0 and 1 were used to cover a wide range of operating conditions. This data included 1683 data points from 50 sources. The comparison of the existing experimental data base with different correlations showed that the Cavallini et al. correlation had a mean absolute deviation of 19%, followed by those made by the correlations of Koyama and Yonemoto (24%), Dobson and Chato (24%), Huang et al. (24%), Shah (29%), and Haraguchi et al. (33%). Based on this comparison, an improved correlation modelled after the correlation of Cavallini et al. correlation was proposed. The accuracy and reliability of the proposed correlations were evaluated by comparing the predicted values with independent experimental data from the literature, wherein it was found that this new correlation predicted the databank with a mean absolute error of 17%. It was also found that this new proposed correlation provided better predictions of the heat transfer coefficient than existing correlations. The proposed correlation will improve the design and optimization of heat exchangers used in various industries, as well as provide valuable insights into condensation behavior inside smooth macro-tubes. [ABSTRACT FROM AUTHOR]

To decarbonize the Nigerian power sector and ensure a reliable electricity supply, nuclear power will play a key role. However, public acceptance must be considered for the successful introduction of nuclear power. This study examines the perceptions of Nigerians towards nuclear power generation and its opportunity as a viable source of power in Nigeria. The study adopts a quantitative method through surveys, using simple random sampling by administering questionnaires of structured close-ended questions to 10,001 respondents via social networking services and handdelivered questionnaires. However, the response rate was only 71%. The data were analyzed using Pearson's Product Moment Correlation to measure the relationship between the various perceptions of nuclear power as a viable solution to the electricity problems in Nigeria using the statistical analysis software, Statistical Product and Service Solutions Statistics (IBM SPSS). The Cronbach's alpha value of 0.821 of the items (questions) illustrates the acceptable internal consistency of the study and shows that it has reliability and validity on a five-point Likert scale. The study shows that over 56% of the respondents support the use of nuclear power generation as a viable option for electricity supply in Nigeria. Furthermore, it is recommended as a boost to the Nigerian economy, safety, security, and environmental sustainability, therefore, indicating positive perceptions towards building a nuclear power plant in Nigeria. [ABSTRACT FROM AUTHOR]

In this study, an interrupted microchannel heat sink with rib turbulators was studied for its thermohydraulic effectiveness and entropy generation in a compact space. The rib edges are modified to enhance the overall functioning of the system by reducing the pressure drop. The working fluid used was Al2O3‐water nanofluid, and increasing the Reynolds number and nanoparticle concentration triggered a reduction in the heat sink's maximum temperature. These also offer a decrease in resistance to heat transfer, and there is an improvement in the evenness of the temperature of the interrupted microchannel heat sink, as regions with the likelihood of hot spot reduced drastically. At Re = 100, increasing the nanoparticle concentration from 0% to 4% enhanced the heat transfer coefficient by 38.41% for the interrupted microchannel heat sink‐base (IMCH‐B) configuration. Under similar conditions, the convective heat transfer coefficient for the interrupted microchannel heat sink‐fillet (IMCH‐F) increased by 43.69%. Furthermore, at 0.5% concentration, changing the Reynolds number from 100 to 700 augmented the heat transfer coefficient by 70.65%. Thus, the maximum temperature of the substrate's bottom surface was reduced by 53.83°C when the system was operated at Re = 700 and nanoparticle concentration of 4%. The IMCH‐C also showed relatively close results at all observed volume fractions. For the IMCH‐C, the maximum temperature of the bottom surface was reduced by 41.98°C at Re = 700 when compared with Re = 100% and 4% concentration. Although at high Reynolds numbers and concentrations, the pressure drops are higher, the performance enhancement criteria prove that the nanofluid is superior to water and the edge modifications show significant performance improvement. More importantly, the IMCH‐F heat sink showed the optimum performance based on the performance evaluation criteria at Re = 300 and φ = 2% (ie, at this point, the heat transfer coefficient is maximum and the pressure drop is minimum). On the other hand, the optimal thermodynamic performance was observed at Re = 700 and φ = 4%. The numerical results demonstrated a potential way to exploit nano‐suspensions for thermal applications, especially for high‐energy flux systems with compact space constraints. [ABSTRACT FROM AUTHOR]

The deleterious effects of solar ultraviolet (UV) radiation on humans are of public health concern which demands constant global monitoring and intervention. This study analysed the latitudinal variations in mean daily and multi-year erythemal ultraviolet radiation (EUVR) across 7 states in Nigeria using satellite data from the Total Ozone Mapping Spectrophotometer (TOMS) and Ozone Mapping Instrument (OMI). The latitudes studied were 13° N, 8° N, 6° N and 4° N respectively, using 37 years of data obtained from phases: 1979-1988, 1989-1998, 1999-2008 and 2009-2020. The data obtained were statistically analysed using Ms Excel and MATLAB. The results of this study show that the mean daily EUVR at the selected latitudes ranges from 32.97 to 390 (mW/m 2 ). The results show that Borno State located at latitude 13° N had the highest EUVR, while Rivers State recorded the least EUVR at latitude 4° N. Comparative analysis of all the locations studied indicates latitudinal and longitudinal variations because the eastern axis recorded higher values than its western counterpart on the same latitude. Box and whisker plots in this study summarized the latitudinal variance in the mean multi-year EUVR in each phase. Box and whisker plots from 2009-2020 showed that there was a drastic reduction in mean multi-year EUVR in this phase unlike in the other phases. The findings of this study when compared to the UV index show that the 37 years mean EUVR obtained across Nigeria ranged from 8-10 which is on the "very high" category. This study recommends the implementation of WHO suggestions in preventing the biological effects of solar UV radiation. Furthermore, the Nigerian government should curb ignorance among its citizens by heightening public awareness of the effects of EUVR., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)