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This research paper explores the potential of passive heating and cooling strategies in buildings utilizing geothermal resources. The focus is on renewable energy solutions, including geothermal energy, solar systems, and Earth-to-air heat exchangers, with the aim of reducing energy consumption for cooling and heating loads. The investigation primarily centers on the performance and optimization of the Trombe wall system, a well-known passive solar system. Numerical studies are conducted to analyze the thermal and fluid-dynamical behavior of the Trombe wall system. The findings provide valuable insights into its operational characteristics and efficiency, aiding in the refinement of design approaches and optimization of system performance. The analysis of temperature distributions within the building and underlying soil reveals the stability of soil temperatures throughout the day, indicating its potential as a reliable heat sink and source for heating and cooling. The dynamic variations in room temperatures, influenced by solar flux fluctuations, convection processes, and the functioning of the air-toearth heat exchanger, highlight the importance of effective system design and control for achieving optimal thermal performance. [ABSTRACT FROM AUTHOR]

This study investigates heat transfer phenomena in a building envelope in Bechar, Southwest Algeria, under arid climatic conditions. The meteorological station Energarid provides precise recordings of solar radiation and outdoor temperature. A calibrated model is used to analyze diurnal temperature variations. Wall temperatures exposed to solar radiation are estimated using recorded data. The heating power requirements of the building envelope are determined through a thermal balance approach based on the regulatory technical document from the National Center for Building Studies and Integrated Research. Simulation results demonstrate favorable conditions for achieving thermal comfort, with elevated air temperatures and velocities at the outlet. Incorporating solar energy considerations into architectural design, such as double facades, south-facing orientations, and glazed surfaces, is crucial. These findings highlight significant energysaving potential, particularly in the Bechar region. [ABSTRACT FROM AUTHOR]

This research paper presents a highly significant study on a new type of static mixer, using advanced numerical simulations to assess its mixing efficiency. The mixer's unique T-shaped design with a spherical mixing chamber and side entrances deviates from traditional designs, resulting in smooth fluid-flow and reduced risk of blockages. The mixer employs hydrodynamic pumps to create a vortex, enhancing mixing. Numerical simulations reveal detailed insights into flow behavior and mixing performance, demonstrating an impressive 94% mixing efficiency within a 2 cm diameter sphere. The innovative design and technique offer practical solutions to industrial mixing problems, benefiting the chemical, pharmaceutical, and related industries. The high mixing efficiency leads to cost savings and improved product quality, while achieving the highest mixing index at Re = 650 sets a new milestone in static mixing. These findings contribute to applied mechanics and optimize industrial mixing processes. [ABSTRACT FROM AUTHOR]

Numerical simulations, based on relatively complex physical models developed for CFD, can accurately predict engine-out responses, but they require huge memory space and/or computation time. In terms of resources and computer time, artificial intelligence methodologies are more cost-effective. In this work, we used an ANN to predict the performance and exhaust emissions of a single-cylinder Diesel engine running on fossil diesel, biodiesel, and their blends under various speed and load regimes. To perform the modeling, we employed multilayer perceptrons and a back-propagation gradient algorithm with momentum to train the network weights. The modification of the network weights was done using the second-order method of Levenberg-Marquardt, and the technique of early termination was utilized to avoid overtraining the model. The study involved using 70% of the complete experimental data to train the neural network, allocating 15% for network validation, and reserving the remaining 15% to evaluate the trained network effectiveness. The ANN model that was created demonstrated remarkable accuracy in predicting both engine performance and emissions. This is evident from the strong correlation coefficients observed, which ranged from 0.987 to 0.999, as well as the low mean squared errors ranging from 7.44·10–4 to 2.49·10–3. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of the dynamic and thermal behavior of air-flow within a heat exchanger equipped with two distinctive baffles: a perforated baffle and a partially inclined baffle. The influence of hole positioning in the perforated baffle on the overall performance of the heat exchanger is thoroughly investigated through a systematic examination of temperature curves at varying Reynolds number values. The results demonstrate significant enhancements in flow characteristics attributed to the presence of these baffles. The flow structure exhibits prominent main currents across the gaps and secondary currents through the holes. The inclusion of these barriers leads to significant deformations and the emergence of well-developed recycling cells in the form of vortices. Both the perforated and inclined baffles effectively reduce pressure values on their frontal regions, thereby mitigating friction losses. Furthermore, the introduction of a perforation in the lower part of the baffle induces a more turbulent flow compared to the other cases. This is attributed to the expansion of the recirculating cells, resulting in improved fluid mixing and subsequent enhancement of thermal energy gain. These findings offer valuable insights into the design and optimization of heat exchangers, enabling improved performance and efficiency in various engineering applications. [ABSTRACT FROM AUTHOR]

In this study, the coldest days of 2022 in the Djelfa region, Algeria, were determined using astronomical and climatic data. The timing of sunrise, sunset, and duration of sunlight, as well as changes in solar radiation intensity and air temperature, were analyzed. By converting solar radiation into heat and solving differential equations, the study examined water exit temperature, thermal energy, and total yield as outputs of a renewable energy converter. The effect of different glass coverings on these outputs was also investigated. The coldest day in 2022 was found to be the first day of January, with nine hours and 43 minutes of sunlight, a maximum solar radiation intensity of 670.34 MW/m², and a maximum air temperature of 16.9 °C. The outputs of the solar center followed a parabolic pattern for the first two parameters and increased over time for the remaining outputs, regardless of the glass type. However, using glass with a high emission coefficient, such as clear monochromatic glass, resulted in the highest values for the outputs: 52.57 °C, 7.5 kW, 162 MW, and 70.62%. By understanding solar energy conversion and thermal behavior, the study contributes to energy-efficient designs and renewable integration, aiding in sustainable urban development. Findings can inform decision-makers in optimizing material selection, promoting resilient infrastructure, and advancing sustainable practices for a low-carbon future. [ABSTRACT FROM AUTHOR]

This article is devoted to the even entire functions, which are the exact solutions for the Laplace and diffusion equations. These functions are considered in the algebraic number field. We guess that the functions have purely real zeros in the entire complex plane. These are proposed as new connections with algebraic number theory and mathematical physics. [ABSTRACT FROM AUTHOR]

In this paper we present a new method of wavelets, based on generalized Gegenbauer- Humberts polynomials, named generalized Gegenbauer-Humberts wavelets. The operational matrix of integration are derived. By using the proposed method converted linear and non-linear fractional differential equation a system of algebraic equations. In addition, discussed some examples to explain the efficiency and accuracy of the presented method. [ABSTRACT FROM AUTHOR]

In this study, a numerical discrete derivative technique for solutions of Kuramoto- Sivashinksy equation is considered. According to the procedure, differential quadrature algorithm is adapted in space by using Chebyshev polynomials and explicit scheme is constructed to discretize time derivative. Sample problems are presented to support the idea. Numerical solutions are compared with exact solutions and also previous works. It is observed that the numerical solutions are well matched with the exact or existing solutions. [ABSTRACT FROM AUTHOR]

In this article, studied the properties of the oscillation of fractional difference equations, and we obtain some results. The results we obtained are an expansion and further development of highly known results. Then we showed them with examples. [ABSTRACT FROM AUTHOR]

This paper proposes a new technique which rests upon Legendre wavelets for solving linear and non-linear forms of fractional order initial and boundary value problems. In some particular circumstances, a new operational matrix of fractional derivative is generated by utilizing some significant properties of wavelets and orthogonal polynomials. We approached the solution in a finite series with respect to Legendre wavelets and then by using these operational matrices, we reduced the fractional differential equations into a system of algebraic equations. Finally, the introduced technique is tested on several illustrative examples. The obtained results demonstrate that this technique is a very impressive and applicable mathematical tool for solving fractional differential equations. [ABSTRACT FROM AUTHOR]

In this paper we discuss parameter estimation in black scholes model. A non-parametric estimation method and well known maximum likelihood estimator are considered. Our aim is to estimate the unknown parameters for stochastic differential equation with discrete time observation data. In simulation study we compare the non-parametric method with maximum likelihood method using stochastic numerical scheme named with Euler Maruyama. [ABSTRACT FROM AUTHOR]

The aim of this work is to determine an approximate solution of a fractional order Volterra-Fredholm integro-differential equation using by the Sinc-collocation method. Conformable derivative is considered for the fractional derivatives. Some numerical examples having exact solutions are approximately solved. The comparisons of the exact and the approximate solutions of the examples are presented both in tables and graphical forms. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses articles in the issue on topics including heat, mass and momentum transfer.

An introduction is presented in which the editor discusses articles in the issue on topics including fluid flow, structural mechanics and semiconductor modelling.