Galaxies are one of the most interesting and complex astronomical objects statistically due to their continuous diversification caused mainly due to incidents such as accretion, action, or mergers. Multivariate studies are one of the most useful tools to analyze this type of data and to understand various components of it. We study a sample of the local universe of Orlando 509 galaxies, imputed with Predictive Mean Matching(PMM) multiple imputation algorithm, with the aim of classifying the galaxies into distinct clusters through k-medoids and k-mean algorithms and in turn performing a heuristic evaluation of the two partitioning algorithm through the percentage of misclassification observed. From the clustering algorithms, it was observed that there were four distinct clusters of the galaxies with misclassification of about $1.96\%$. Also comparing the percentage of misclassification heuristically k-means is a superior algorithm to k-medoids under fixed optimal sizes when the said category of galaxy datasets are concerned. By considering that galaxies are continuously evolving complex objects and using appropriate statistical tools, we are able to derive an explanatory classification of galaxies, based on the physical diverse properties of galaxies, and also establish a better method of partitioning when working on the galaxies.

Fabricating conformal cooling channels (CCCs) has become easier and more cost-effective because to recent advances in additive manufacturing. CCCs give better cooling performance than regular (straight drilled) channels during the injection molding process. The main reason for this is that CCCs may follow the paths of the molded shape, but regular channels cannot. CCCs can be used to decrease thermal stresses and warpage while also decreasing cycle time and producing a more uniform temperature distribution. Traditional channels, on the other hand, have a more involved design technique than CCC. Computer-aided engineering (CAE) simulations are crucial for establishing an effective and cost-effective design. The goal of this paper is to compare two ANSYS modules for the purpose of verifying findings. For models with fine mesh, the two modules appear to provide equivalent results. As a result, the ANSYS module to use should be determined by the job's purpose as well as the complexity of the CAD geometry.

The Burr III distribution is extended in this work as a substitute for the numerous Burr III distributions. A new distribution is developed by applying the log transformation technique to define the transformed log-Burr III distribution. Moment generating function, moments, entropies, and stress-strength models, among other structural features, were established. The order statistics with minimum and maximum were introduced, and the model parameters are derived using the maximum products of the spacings technique. The applicability of the new distribution was assessed using real-world data on the transformed total milk production in the first birth of 107 cows of the SINDI race. The results showed that the revised distribution might be used as the optimal distribution for this data set.

Magnetic carbon xerogels composite with Fe₃O₄ nanoparticles (MNPs) prepared by co-precipitation can effectively remove arsenic (As(V) and As(III)) and fluoride ions from groundwater. The optimum conditions for the synthesis of these materials were studied, including the molar ratios of MNPs, and catalyst. Carbonization and post-synthesis treatment with H₂O₂-induced surface modification were applied. SEM and Fe analysis revealed the presence of Fe in the materials. This study provides a promising new method for the removal of arsenic and fluoride from groundwater, with the feasibility of reusing adsorbent and magnetic separation, which could have a significant impact on public health.

Cameroon has a high potential for numerous energy resources. However, the country still relies heavily on hydropower (approximately 88%) as primary source of electricity. In spite of this high concentration on hydro, the generated energy is still very insufficient. As a consequence, the country is plagued by several electricity challenges, with approximately ten electrical outages per month, which last for an average of two hours. In this light, the country is currently investigating on the effective exploration of alternative energy sources. Among the energy resources being sorted, solar energy is the most abundant, clean, and renewable source available. PV system performance are largely dependent on location and operating conditions. Considering the heavy reliance on weather conditions, the close monitoring and evaluation of such a system can provide information on short-term or long-term corrective measures. In the context of Cameroon, it is extremely difficult to have access to reliable PV data. This is due to the high cost of PV measurement equipment or the acquisition of satellite weather data whose reliability and accuracy are still questionable. To overcome such challenges, this paper introduces a Trio-PV-systems monitor for consistent and continuous monitoring of PV systems. The Trio device is a smart system that embody an electronic hardware, desktop application and a website. The system is especially designed to provide consistent monitoring, storage, sharing as well as analytical power to engineers and scientists on solar energy related data at any chosen site. The overall system features high flexibility, with wide range weather-proof sensors, permitting the monitoring and evaluation to cut across seasons and different geographical areas. Additionally, the system is suited for PV plants of up to 100KW rating. The automated design of the system allows it to consistently operate for 12 hours within a day. In addition, the system is grid-energy independent, thus the control unit has continuous power to consistently operate the sensors and collect the data for storage and sharing. Therefore, the proposed IoT -based system is aimed at providing a reliable and continuous monitoring of the PV parameters, including PV voltage, current and power, the ambient and module temperature, the relative humidity and irradiance. The Trio-PV-system monitor has been tested and evaluated on a twelve-hour basis. The acquired results revealed satisfaction and consistency between the data collected on the desktop and that displayed on website. Graphs showing the evolution of each parameter with time can be viewed directly by use of the graphical interface provided on the desktop application. The production parameters on the chosen site can be evaluated at any location in the world by authorized users. This system will be of great use in developing countries, especially Cameroon where access to information on PV systems is costly.

Due to urbanization, it is near impossible to construct civil infrastructures without encountering soil materials with poor geotechnical response. In soil re-engineering, the trending practise is the use of supplementary cementitious material with the aim of reducing carbon footprint and construction cost. This has necessitated the usability of integrating the blends of palm oil fuel residue (POFR) and calcium carbide residue (CCR) in the amelioration protocols of two soil materials. The amelioration protocols were implemented by inclusion of 0, 2, 4, 6, 8 and 10 % dosages of POFR and 0, 2, 4, 6, and 8 % dosages of CCR by requisite weight of soil materials. The experimental works were carried out in three phases, namely: material characterisation, mechanical performance and microstructural testing. Judging from the index performance, BCS and RLS are clayey materials having a plasticity index of 28.70 and 18.97 % respectively. With regard to the mechanical performance (compaction, California bearing ratio and durability), the inclusion of the blends of POFR-CCR into the soils (BCS and RLS) activated a positive response and was later validated via means of microstructural tests. This research has shown the potential of blended waste residues in soil re-engineering studies. The study was vividly achieved through qualitative approaches, namely: scanning electron microscopy and Fourier transform infrared.

The beam-column connection is a fundamental element in frame structures and requires special attention in the calculation of the forces passing through it and the corresponding modeling. Often the joint is assumed to be rigid, but this does not correspond to the real behavior of the beam-column connection, as well as the real response of the frame structures. For the study of the moment-resisting frame in the leading countries in seismic research, uniform procedures have been introduced. However, in their seismic codes, there is still a discrepancy in how the shear force is determined in the beam-column connection.
In the present paper, a new mathematical model is proposed for the analytical determination of the forces passing through the joint in the beam-beam and column-column direction. The occurring large deformations in the beam and the column, which can be realized during an earthquake, are take into account. The material is elastic. The tensile/compressive stiffnesses and the bending stiffnesses were taken into account after superposition of the stiffnesses of the various materials making up the cross-section.The obtained values are compared with results determined by mathematical procedures proposed in other literature sources. The results show values of the shear force determined by the new model about 20% greater than those available in the literature.

Europium(II) sulfide (EuS) belongs to the europium chalcogenides [1]. It is a ferromagnetic semiconductor with a Curie temperature of 16 K. While the magnetic properties of EuS have been extensively studied, investigations of its electrical properties are limited.

In this study, EuS thin films with varying thicknesses (15, 25, and 50 nm) were deposited onto a Si/SiO2 substrate using e-beam evaporation. Subsequently, two Ag contact electrodes with a 0.2 mm spacing were prepared via thermal evaporation using a shadow mask. To investigate the influence of film thickness and temperature on the electrical properties of EuS thin films, current-voltage (I-V) measurements were performed in a temperature range of 300-433K for a voltage range of -2V to +2V. The I-V characteristics exhibited a temperature-dependent behavior, particularly showing an increase in current with rising temperature in the forward bias region. Furthermore, an improvement in Schottky behavior was observed with increasing EuS film thickness. Additionally, the AC electrical and dielectric properties of the EuS thin film were examined in a frequency range of 4 Hz–8 MHz. Capacitance, conductance, impedance, and the Cole-Cole characteristic of EuS were analyzed in detail with respect to frequency, temperature, and film thicknesses.

References

1- Boncher, W., Dalafu, H., Rosa, N., & Stoll, S. (2015). Europium chalcogenide magnetic semiconductor nanostructures. Coordination Chemistry Reviews, 289, 279-288.

Clay and clay composite have been used for numerous applications around the world including as construction materials, cosmetics, and absorbents. As easy to find, abundant, and sustainable, the knowledge of the quality of clay is crucial. This study focuses on the characterization of geophagic clay samples from various locations in the Democratic Republic of Congo (DRC) to investigate their potential use in various sectors. The geophagic clays have different colors, different morphology, and properties. Many characterizations were carried out including X-ray diffraction, X-ray fluorescence spectroscopy, and fourier transform infrared (FTIR). The microstructure and chemical analysis were carried out using scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS). UV-Vis spectroscopy was also carried out to investigate the reflectance. XRD revealed the presence of Muscovite, Kaolinite, Illite, Muscovite, and Quartz. On the other hand, XRF showed the presence of SiO₂, Al₂O₃, TiO₂, and Fe₂O₃ as major chemical compounds. A flake-like surface morphology was observed in all the samples and the EDS analyses exhibited similar results as the XRF. The XRF, XRD, and EDS results were in agreement. The Zeta potential was negative for all the clay samples. The properties exhibited by the selected geophagic clay were compared with the properties of various samples used for different applications. It was concluded that the selected geophagic clays demonstrated properties that could lead to their use for water treatment and other applications including the cosmetic industry.

Compared to the classical inverters, the multilevel inverter finds remarkable advantages, which can be suitably implemented in green energy power generation. Here an asymmetric multilevel inverter with fewer components is proposed for renewable energy applications. The proposed inverter is a cross between two H bridge-style devices. To maximize the output voltage three different algorithms to fix the amplitude of the DC sources are proposed and the best among them is chosen for implementation. The recommended inverter can generate 19 levels of output voltages using three DC sources with reduced power components. The nearest level modulation is used as the control course for the inverter. Here MATLAB software is used to simulate the proposed inverter and the performance of the inverter is observed. The proposed inverter is constructed in real-time, and the performance of the inverter is studied by testing with fixed and variable reactive loads. A comparative study is made between the simulation model and real-time work results in-terms of efficiency and harmonics in the load wave-forms.