Values Of Parameters Research Articles

On the handling of inconsistent systems of max-min fuzzy relational equations

In this article, we study the inconsistency of systems of max-min fuzzy relational equations. We first compute by an explicit analytical formula the Chebyshev distance (defined by the L-infinity norm) between the second member of an inconsistent system and the set of second members of consistent systems defined with the same matrix: that of the inconsistent system. Then we study the set of Chebyshev approximations of the second member of the inconsistent system, which are the second members of the consistent systems defined with the same matrix as the inconsistent system, whose distance to the second member of the inconsistent system is equal to the computed Chebyshev distance. This set is non-empty and associated to the approximate solutions set of the inconsistent system in the following sense: an approximate solution is a solution vector of a consistent system defined with the same matrix as the inconsistent system, whose second member is a Chebyshev approximation of the second member of the inconsistent system. As main results, we describe both the structure of the approximate solutions set and that of the set of the Chebyshev approximations of the second member of the inconsistent system. As an application of our results, we show that our work can help to find approximate values for the rule parameters of a possibilistic rule-based system.

Cosmic expansion history analysis with Hubble parametrization in Qn gravity

In this paper, we propose a specialized parameterization for the Hubble parameter, inspired by [Formula: see text]CDM cosmology, to investigate the cosmic expansion history of the Universe. This parameterization is employed to analyze the universe’s late-time behavior within the context of [Formula: see text] gravity, where [Formula: see text] represents non-metricity. By using data from 57 Hubble data points, 1048 supernova (SNe) data points, and six Baryon Acoustic Oscillation (BAO) data points, we determine the optimal values for the model parameters. Additionally, we explore three distinct cosmological models based on the parameter [Formula: see text], specifically when it takes on the values of [Formula: see text], [Formula: see text] and [Formula: see text]. The results of our analysis indicate that our proposed parameterization, along with the associated models for different values of [Formula: see text], predicts an accelerated cosmic expansion phase.

Study of the matrix–particle interactions of polymer nanocomposites in the low‐frequency regime

AbstractIn this study, the dynamic moduli, in a wide frequency scale, of two series of polymer nanocomposites were qualitatively discussed. The dynamic mechanical analysis experimental results of polylactic acid (PLA)/silica nanocomposites, as well as PLA/graphene oxide‐carbon nanotubes hybrid nanocomposites, were employed. The study has been focused on the low‐frequency regime, estimating the terminal incline of the storage and loss modulus. In addition, the relative position of the two dynamic moduli was examined and results about the nanofiller's dispersion quality, as well as their interaction with the matrix were extracted. The consequence of nanofiller kind, loading, and distribution quality on the mechanical enhancement was thoroughly studied. In addition, the storage modulus master curves could be simulated by a model from the literature, considering the topological constraints of an entangled polymer reinforced by nanoparticles. It was shown that by adopting the linear contribution of the free and adsorbed chains to the relaxation function, the details of the master curves could be captured in the entire frequency range, quite effectively. The estimated model parameter values confirmed the analysis of the matrix–particle interactions.Highlights The SiO2 size effect on the terminal zone slope of the dynamic moduli. Successful description of the dynamic moduli by the tube reptation concept. Analysis of the physical meaning of the model parameter values. Relation between SiO2 dispersion quality and molecular motion restriction. Matrix‐particle interactions is the governing mechanism of enhancement.

On the interaction between the search parameters and the nature of the search problems in search‐based model‐driven engineering

AbstractThe use of search‐based software engineering to address model‐driven engineering activities (SBMDE) is becoming more popular. Many maintenance tasks can be reformulated as a search problem, and, when those tasks are applied to software models, the search strategy has to retrieve a model fragment. There are no studies on the influence of the search parameters when applied to software models. This article evaluates the impact of different search parameter values on the performance of an evolutionary algorithm whose population is in the form of software models. Our study takes into account the nature of the model fragment location problems (MFLPs) in which the evolutionary algorithm is applied. The evaluation searches 1895 MFLPs (characterized through five measures that define MFLPs) from two industrial case studies and uses 625 different combinations of search parameter values. The results show that the impact on the performance when varying the population size, the replacement percentage, or the crossover rate produces changes of around 30% in performance. With regard to the nature of the problems, the size of the search space has the largest impact. Search parameter values and the nature of the MFLPs influence the performance when applying an evolutionary algorithm to perform fragment location on models. Search parameter values have a greater effect on precision values, and the nature of the MFLPs has a greater effect on recall values. Our results should raise awareness of the relevance of the search parameters and the nature of the problems for the SBMDE community.

Qualitative study of anisotropic cosmologies with inhomogeneous equation of state

We examine the qualitative features of anisotropic models sourced by the fluid having an inhomogeneous equation of state (EoS). In particular, we study the asymptotic behavior and cosmic dynamics of the locally rotationally symmetric Bianchi I, Bianchi III and the Kantowski–Sachs spacetime by using the dynamical system technique. The dark energy yielded by the inhomogeneous EoS leads to the accelerated expansion of the universe with vanishing shear at late-times. We further extract the geometrical and physical features of the cosmological dynamical system by rewriting the statefinder diagnostic and cosmographic parameters in terms of its dynamical variables. The model parameters are constrained for the quintessence and phantom evolution of universe. On the basis of model parameter values, the Kantowski–Sachs model undergoes synchronous bounce during its evolution.

Computation analysis of unsteady second grade biomagnetic micropolar blood base nanofluid flow with motile gyrotactic microorganisms

ABSTRACT The primary aim of this research is to investigate the impact of an external magnetic field on bacteria that are surrounded by a large quantity of magnetite nanoparticles. The study utilizes magnetite F e 3 O 4 nanofluid using blood as a base fluid with variable thermal conductivity, in which a synthetic bacterium moves within a biological cell. The focus of the study lies in analyzing the non-steady movement of a micropolar fluid in a two-dimensional context, specifically in the presence of a curved porous wall. Suitable transformations are used to transform the nonlinear PDEs to their corresponding nonlinear ODEs. The HAM (Homotopy Analysis Method) is used to find the mathematical results. The impact of various key parameters is studied by using numerical tables and graphs. This study shows that the velocity curves of the pure blood is higher than those magnetite/blood. Clinical disease shows that perilous tumors have weakened blood flow. This study demonstrates that higher parameter values lead to an improvement in the blood velocity profile, indicating that medication therapy reduces tumor size and aids in countering distorted cells. Furthermore, the research reveals that an increase in the concentration of magnetite nanoparticles corresponds to an increase in the distribution of blood temperature. The findings of this study highlight the significant role played by thermal conductivity in enhancing the rate of heat transfer.

Effects of Liquid Fertilizers on Growth Performances of Ipomoea aquatica in Coir-Based Growing Media

In the process of crop management, fertilization must be practiced in an appropriate way to maintain the sustainability. Hence, the right type of fertilizer and the correct mode of application is crucial. The source and the physical nature of the fertilizer is having a significant effect on the performance of plants. In that context, liquid fertilizers are generally a convenient and effective way to enhance the nutrients availability. Hence, the present study was conducted to evaluate the effect of several liquid fertilizers on the growth performance of the popular leafy vegetable Ipomoea aquatica. Plants were established in coir grow blocks and treated with five different commonly known and available liquid fertilizers namely, Albert’s solution (T1), Compost tea (T2), Vermiwash (T3), Sanstha liquid fertilizer (T4) and Gliricidia leaf extract (T5) once a week by applying a constant volume of 100 mL. The experiment was arranged in a randomized complete block design (RCBD) inside a semi protected plant house. The growth parameters of the plants (plant height, number of leaves, leaf area, fresh weight, and dry weight) were recorded up to 60 days. One-way Analysis of Variance (ANOVA) was used for statistical comparisons. According to the results all the parameters denoted significant differences among the treatments (P<0.05), except for chlorophyll content. However, T1 denoted the highest mean values for the vegetative parameters including, plant height, number of leaves, leaf area, fresh weight, and dry weight while T3 (Vermiwash) reported the second highest values for the respective parameters. Regarding the chlorophyll content the highest mean value was recorded by T2 (Compost tea) followed by T5 (Gliricidia leaf extract). The results of the present study indicated that liquid fertilizers can be used effectively for the production of I. aquatica in coir-based media. It suggested Albert’s solution and vermiwash as high potential liquid fertilizers while vermiwash can be recognized as a nutrient supplement for organic production of Ipomoea aquatica in coir-based media.
 
 Keywords: Compost tea, Ipomoea aquatica, Liquid fertilizer, Vermiwash

Удосконалення методики проєктування контейнерного терміналу

The purpose of the article is to develop a refined methodology for the general design of a container terminal. The difference between the proposed design methodology and the existing ones is that a solution is proposed to change its throughput (annual container flow passing through it), without changing the dimensions of the container yard and the way containers are stored, that is, with the same capacity of the container yard. Such cases occur, for example, when it is necessary to reconstruct a container terminal. Cargo terminals for containers are a specific area of logistics and cargo delivery systems, where cargo is processed in consolidated transport modules – containers. The main stages of analyzing or projecting a warehouse as a complex stochastic technical system should be considered: objective setting (it should be single); selection and determination of elements of technological areas and warehouse structure, as various connections between system elements; analyzing of system functioning (including its simulation); consideration of system interaction with surrounding environment; consideration of results of the warehouse system performance, and operation. It is interesting to point out that this general methodology can be used while creating or analyzing any other transformation of technical or social system, which receives a flow of some objects with one set of parameters, processes it through its structure, and gives them out with other values of parameters. 
 This method of formalizing the functioning of the container terminal can be used for its calculations, modeling, research and optimization. In the processes of interaction with environmental systems, the container terminal passes from one state to another, which are characterized by the types and volume of technological operations that must be performed at the moment, cargo that must be stored, delivered to and from the terminal, assembled, sorted, business employee processes, forklifts, cranes and other equipment in use. The functioning of the container terminal (part of the warehouse system) as a procedure of transitions from one state to another can be represented in the form of a graph or transition probability matrix.

Preliminary Analysis of Air Conditioner Condensate Water Generation in Buttala, Monaragala, Sri Lanka

In tropical countries like Sri Lanka, a significant amount of air-conditioner (A/C) condensate water is often discharged into the environment without being utilized. Although considerable number of reports available for South and East Asia, research related to AC condensate in Sri Lanka is scanty. The aim of this research was to analyse the quality and quantity of the discharged condensed water after understanding the potential environmental concerns. Monaragala district was chosen for this study due to its dry climate and the widespread use of air conditioners in most shops, resulting in a substantial discharge of condensed water into the environment. Water samples were taken from 31 institutions within Buttala area. These samples were collected in triplicate, and the mean value was used for analysis. When considering all parameter values, pH, TDS, Turbidity, Electrical Conductivity, and color showed good compliance with the SLS 614:2013 and NEA standards. (Mean values were 7.317, 28.37 ppm, 1.47 NTU, 54.21 µS, 10.74 and standard deviation values
 were 0.1138, 13.46, 0.1961, 26.01, 5.047 respectively). Therefore, the condensed water from air conditioners is unlikely to have environmental impacts and can be safely used for irrigation and agricultural purposes. In the case of potable water, all the parameters analyzed in this research were well-fitted with the potable water standards. However, if it is intended for drinking purposes, further analysis for heavy metal contamination is required. By considering 11 number of A/C units, an amount of condensed water 0.97L/h/ton is released to the environment; equivalent to approximately
 7.76 L/ton per day. The values were taken in duplicates. The volume of condensate water, while considerable, doesn’t need to be released into the environment without purpose. Instead, this water can be efficiently utilized for various applications, including garden irrigation, toilet flushing, cooling applications, cleaning, fire suppression, and construction. This suggestion is imperative, not only for the Buttala area but for the entire country of Sri Lanka, as this approach can yield several positive effects on both the environment and the economy.
 
 Keywords: Air conditioners, Condensed water, Quality analysis, Quantity analysis

Покращення динамічних властивостей засобу рухомості озброєння шляхом встановлення дизельних двигунів при проведенні модернізації

This article examines the possibilities of improving the dynamic properties of a weapon vehicle by installing diesel engines during modernization. It proposes a number of practical measures to achieve this goal, such as replacing a gasoline engine with a diesel engine.The article conducts a comparative analysis of the traction and dynamic characteristics of the basic gasoline power unit and the diesel power unit installed after modernization on the example of APCS 70. The necessity of modernization by replacing gasoline engines with diesel units is substantiated by means of a comparative traction and dynamic calculation and economic indicators of power units. A comparative analysis of fuel consumption is carried out and the power of the power units is compared. The disadvantages of using gasoline power units are analyzed. According to the results of the calculations, the optimal ratio of parameters that determine the dynamic properties of the vehicle of the weapon is achieved.For the calculation of the main indicators of traction and speed properties of the prototype, the numerical values of the design parameters of the APCS 70 product, which are given in the reference literature, are used.The modernization discussed in this article involves further refinement of the APCS 70's power plant compartment, which is located in the aft part of the hull. It contains two ZMZ 4905 power units assembled with clutches and gearboxes mounted on a common frame. The gasoline power units are replaced with clutch assemblies and 4-speed transmissions. Diesel power units are assembled with clutches, equipped with 5-speed gearboxes and are installed with minor modifications to the standard subframe on which the units are mounted. In turn, the replacement of the power units entails further modifications to the cooling system, fuel supply, exhaust system, engine heating system, as well as part of the electrical equipment of the power units. The transfer case and subsequent transmission of the product remain unchanged.The research provides valuable information for military equipment specialists and engineers interested in improving the performance of combat vehicles.

Design and analysis of optimal AGC regulator for multi‐area power systems with TCPS and energy storage unit in deregulated environment

AbstractIn today's electric power network, fast changes are the norm, and auxiliary services such as automatic generation control (AGC) play a crucial role in maintaining the quality of the power supply. AGC ensures a balance between power generation, demand, and losses to sustain frequency stability and variation in tie‐line power within a set limit, even when the load changes. To accomplish this, it is always beneficial to consider new approaches to controlling the situation. This paper introduces the design of new AGC regulators that consider deviation in DC tie‐line power as an extra control variable for the turbine controller. In this study, three different deregulated power systems (containing two control areas), namely three thermal generations, the combination of one thermal and two hydro generations, and three hydro generations, including two power distribution companies (DISCOs) in each control area. These optimal AGC regulators are implemented in the proposed thermal–thermal–thermal system to carry out the various power contracts. The results have shown that the dynamic outcomes meet the AGC standards. To improve further dynamic results and the proposed systems' stability margins by incorporating redox flow batteries (RFB). In actual operating conditions, the system parameters do not remain constant due to the aging effect, assumptions made in simplifying the mathematical model, etc. Thus, ±50% deviations in the nominal value of system parameters to assess how well the optimal AGC regulators perform in the system under investigation. The suggested realistic AGC system incorporates many parameter fluctuations and works well with the optimal AGC regulators developed for the proposed plans. This study expanded to include a two‐area, thermal‐hydro‐hydro (THH) system under a deregulated framework connected via an asynchronous transmission link with or without a thyristor‐controlled phase shifter (TCPS) and RFB. The genetic algorithm (GA) can solve many issues and has global search, flexibility to varied problem types, intrinsic parallelism, and the ability to handle massive, complex search spaces. Thus, a two‐area deregulated hydro‐hydro‐hydro system with parallel tie‐lines utilizes GA‐PID, GA‐FOPID, and GA‐(1 + PI)‐FOPID controllers. Moreover, a random load disturbance (RLD) is employed in each section of the offered approach to show the resilience and elite performance of the proposed control strategy. To produce various dynamic reactions in the plans, MATLAB software version R2013a is employed.

Multiphysics Study of Thermal Profiles and Residual Stress in Welding.

One of the effects of welding is residual stress. Welding involves complex tests concerning differences in values of the mechanical parameters of its regions as an effect of residual stress. Such multiphysics characteristics of welding pose a challenge in predicting residual stress. In the present study, a thermo-mechanical constitutive model considering phase transformation and transformation plasticity is implemented in the numerical model in ABAQUS user subroutines. In order to consider phase evolution in welding, the metallurgical parameters for Leblond's phase equation were obtained from the calibration of DH36 steel with a CCT diagram. In addition, the effects of welding speed on thermal profiles and residual stress generation were investigated. Analysis has suggested that the width of the heat-affected zone (HAZ) decreases with an increase in welding speed, and the phase fraction is significantly affected by this kind of parameter. Such phase transformation has led to the generation of a compressive stress in the fusion zone (FZ) and HAZ. The volume difference between coexisting phases produces a compressive stress in cooling, and its magnitude was increased with martensite increasing.

The shadow of Kerr-Newman black hole surrounded by perfect fluid matter in Rastall gravity

We investigate analytically the apparent shadows cast by Kerr-Newman black hole with surrounding perfect fluid matter in Rastall gravity theory. With the help of the Hamilton-Jacobi equation and Carter constant separable method, we derive the null geodesics of the black hole space-time and calculate the numerical results of the horizon structures. The results reveal that three horizons (Cauchy horizon r −, event horizon r + and cosmological horizon r q ) occur in the space-time, and the horizon structure could degenerate while the Rastall parameter k λ arrives the critical value. By fixing the value of equation state parameter ω˜ of surrounding substance for both cases of dark matter ( ω˜=−1/3 ) and dark energy ( ω˜=−2/3 ), we study the effects of the perfect fluid matter intensity N s , the Rastall parameter k λ, the black hole spin a and the black hole charge Q on black hole shadows in detail. Furthermore, the effective potentials for black hole space-time and the energy emission rate of the black hole are also conducted and discussed.

Long-term averages of the stochastic logistic map

ABSTRACT The logistic map is a nonlinear difference equation well studied in the literature, used to model self-limiting growth in certain populations. It is known that, under certain regularity conditions, the stochastic logistic map, where the parameter is varied according to a specified distribution, has a unique invariant distribution. In these cases we can compare the long-term behaviour of the stochastic system with that of the deterministic system evaluated at the average parameter value. Here we examine the relationship between the mean of the stochastic logistic equation and the mean of orbits of the deterministic logistic equation at the expected value of the parameter. We formally prove that, in some cases, the addition of noise is beneficial to the populations, in the sense that it increases the mean, while for other ranges of parameters it is detrimental. A conjecture based on numerical evidence is presented at the end.

Referentne vrijednosti za odabrane hematološke i biokemijske parametre u pelagonijske pramenka ovce

The Ovcepolian type of Pramenka sheep is most prevalent in Pelagonia region. It is considered a valuable source of genetic diversity, characterised with a number of beneficial traits. Haematology and biochemistry measurements is important for health assessment of animals. The aim of this study was to determine the reference ranges for selected haematology and biochemistry parameters in the Pelagonian Pramenka sheep breed. The study was carried out on 55 clinically healthy, non-pregnant sheep, 1 to 3 years old, during spring season, from three different locations in the Pelagonia region, North Macedonia. Blood samples were collected from the jugular vein into vacuum tubes with an anticoagulant for haematological analysis and vacuum tubes free of anticoagulant for biochemical analysis. Reference values may be more adequate as it is later, for biochemistry parameters. Reference values for hematology parameters were: leukocytes, lymphocytes, midsize cells, cells correlating to monocytes, eosinophils, basophils, blasts and other precursor white cells, granulocytes, haemoglobin, haematocrit, erythrocytes, erythrocyte indices (average volume per litre, average haemoglobin in erythrocytes, average haemoglobin concentration per litre, and platelets). Reference values for biochemistry parameters were: total proteins, albumins, total bilirubin, total cholesterol, creatinine, glucose, HDL-cholesterol LDL-cholesterol, triglycerides, urea, aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, glutamyl transferase, lactate dehydrogenase, and the concentrations of calcium, magnesium and inorganic phosphate. Most obtained values were comparable to other strains of Pramenka sheep. There was a clear deviation of certain reference values compared to the literature. Further analysis should be conducted to determine the reference values in rams and lambs.

Analisis Pengaruh Penggunaan AAU pada Swap RRU terhadap Kualitas Layanan Telekomunikasi di Wilayah Pusdikom Cibeureum Cimahi

Telecommunications technology continues to undergo advancements. The enabler of communication in the field of telecommunications is the telecommunications equipment installed on a BTS tower. These devices are constantly being updated to improve the service provided by the provider to meet the needs of customers. One of the network technologies currently used is 4G LTE. To enhance the network service, one of the measures taken is performing a swap or upgrade of the telecommunications equipment on a BTS tower. The upgrade of telecommunications equipment is also influenced by the population in the vicinity of the BTS tower. This allows for the replacement of telecommunications devices with ones that have broader coverage and better signal quality. This research, we discuss the issue of network capacity shortage in the Cibeureum area, South Cimahi. This is indicated by the addition of AAUs to the BTS tower in Pusdikom, Cibeureum. This research found data that South Cimahi is the most densely populated area in the city compared to other districts. Therefore, the addition of AAUs is highly effective for this issue. It is known that the AAUs are added to replace the RRUs on the tower. This is because the capacity and transmission channels of AAUs are greater than RRUs. The addition of AAU with 32T32R specifications to the tower improves signal quality with the following parameter values: RSRP(dbm): -68, -72, -76; RSRQ(db): -11, -10, -10; and SNR(db): 1, 1, 4. These values are categorized as good, indicating that the addition of AAU to the tower can effectively increase network capacity and transmission channels, thereby improving network quality in the area.

Effect of meniscus modelling assumptions in a static tibiofemoral finite element model: importance of geometry over material.

Finite element studies of the tibiofemoral joint have increased use in research, with attention often placed on the material models. Few studies assess the effect of meniscus modelling assumptions in image-based models on contact mechanics outcomes. This work aimed to assess the effect of modelling assumptions of the meniscus on knee contact mechanics and meniscus kinematics. A sensitivity analysis was performed using three specimen-specific tibiofemoral models and one generic knee model. The assumptions in representing the meniscus attachment on the tibia (shape of the roots and position of the attachment), the material properties of the meniscus, the shape of the meniscus and the alignment of the joint were evaluated, creating 40 model instances. The values of material parameters for the meniscus and the position of the root attachment had a small influence on the total contact area but not on the meniscus displacement or the force balance between condyles. Using 3D shapes to represent the roots instead of springs had a large influence in meniscus displacement but not in knee contact area. Changes in meniscus shape and in knee alignment had a significantly larger influence on all outcomes of interest, with differences two to six times larger than those due to material properties. The sensitivity study demonstrated the importance of meniscus shape and knee alignment on meniscus kinematics and knee contact mechanics, both being more important than the material properties or the position of the roots. It also showed that differences between knees were large, suggesting that clinical interpretations of modelling studies using single geometries should be avoided.

Integrated Assessment of Kirala Kele Wetland Health: Bridging the Gap between Water Quality Parameters and Biotic Components

Abstract The present study was carried out to assess the health of the Kirala Kele Wetland, Sri Lanka, by coupling water quality indices and bioindicators. A total of 12 sampling sites were selected to represent different land-use patterns of the Kirala Kele Wetland using purposive sampling technique, and sampling was conducted from March 2021 to May 2021, on a monthly basis. Triplicated samples (n = 3) were obtained for each sampling event at each sampling site. Aquatic macroinvertebrates were collected from each site to determine the biological water quality using the Biological Monitoring Working Party (BMWP) score. Weighted Arithmetic Water Quality Index (WAWQI) was calculated to understand the physicochemical parameters of water, and the mean values of physicochemical water quality parameters were compared with the Sri Lankan water quality standards. According to the WAWQI for the different sampling sites, water is not suitable for drinking without treatment. The resulted BMWP score (BMWP = 61) shows that the water quality is acceptable (clean but slightly impacted) for biotic components of the wetland in accordance with the aquatic macroinvertebrates present. Spatial variation in water quality parameters and the aquatic macroinvertebrates were taken into account, and the temporal variation in water quality parameters within the 3 months from March to May was considered.

Two layer film flow on an unsteady stretching cylinder

Most of the earlier research works related to the thin film flow over a stretching cylinder are primarily limited to the boundary layer flow of a single liquid. Whereas, multilayer film coating is commonly used to coat microelectronic chips, circuits, etc. This scenario motivated us to investigate the thin double-layer liquid film development over a stretching cylinder. In the present work, the above limitations of earlier models have been removed to investigate the two-layer film flow over a stretching cylinder by considering a full set of momentum equations. The governing set of equations is transformed into a system of nonlinear partial differential equations (PDEs) by applying appropriate similarity transformation. The analytical solutions are obtained by using the asymptotic analysis method for smaller values of Reynolds number (i.e. Re1<<1). Whereas numerical solutions are obtained by implicit finite difference method for smaller as well as moderate values of Re1. It is found that the film thinning rate enhanced for both the liquid layers with raising values of the cylinder’s radius (A) and density ratio (m). It is further seen that both the liquid layers thin faster with a decreasing initial thickness ratio of both liquid layers (δ). It is also observed that the variation of film height for the first layer is very small in comparison to the second layer for increasing values of viscosity ratio parameter (n). The film height for both the liquid layers decreases very fast for a smaller Reynolds number (Re1) at the initial time but a reverse trend is noticed at large time.

Numerical study of linear and nonlinear stability in double-diffusive Hadley-Prats flow through a horizontal porous layer with Soret and internal heat source effects

Numerical analysis is constructed to study the onset of the double-diffusion convection mechanism through an infinite parallel permeable channel with heat generation, mass flow and Soret impacts. Homogenous isotropic Darcy’s flow model is deployed to elucidate the porous features. The roll instabilities pertaining to longitudinal and transverse cases are examined through a linear and nonlinear stability analysis. The unit-less eigenvalue problem is constructed through linear and nonlinear stability assumptions and which is solved numerically using a fourth order Runge-Kutta scheme. The critical values of wave and thermal Rayleigh parameters are evaluated. Extended graphical and tabular visualization is presented to describe the onset of the convection mechanism. The results of this semi-numerical investigation may be useful in environmental, geothermal and chemical engineering processes. In addition, the critical R z value is also determined for a range of thermo-physical numbers. Significant modifications in the flow patterns are computed with mass flow parameter and vertical thermal and solutal Rayleigh number. With an increment in Soret (thermo-diffusive) parameter Sr the regime become more unstable. Based on the nonlinear stability analysis, an elevation in solutal Rayleigh number also induces earlier instability. The collective influence of the Lewis number and horizontal concentration parameter is observed to render the system more stable.