computational modeling

The relevance of this research stems from the necessity to enhance existing vibration-compensation systems for reducing vibrational loads on power units of mainline pumping units (MPUs). Algorithms and computational results of the spatial vibration state of the vibration-compensation system (VCS) for MPUs under various operational regimes are presented. Mathematical and spatial finite-element models, as well as versatile digital prototypes of the VCS, have been developed. The novelty of the findings lies in the developed digital prototype of the MPU, which offers broad capabilities for accounting for design-technological factors, accommodates diverse operational regimes, and exhibits high precision and computational efficiency. The practical significance of the work is that the developed simulation methodology based on digital prototypes of the MPU VCS enables the analysis of vibrational impacts from electric motors, pumps, and load-bearing frames. Comprehensive computational studies of the stress-strain state of the VCS frame were performed, and the system’s natural frequencies during operation were evaluated. The objective of this work is to study the behavior of the pumping unit when replacing elastomeric supports in the compensation system with hydrofilm dampers. An indisputable advantage of the developed digital model is its foundation for a universal methodology to assess the effectiveness of vibration compensators in the MPU VCS. A unique digital prototype of the MPU was developed considering the engineered VCS. The feasibility of using a finite-element-based digital prototype for evaluating vibrational loading on MPUs is substantiated. Numerical experiments using the MPU’s digital twin established that implementing hydrofilm dampers in the VCS reduces peak dynamic stresses by 18%. Values of axial and resultant displacements of the MPU using hydrofilm and elastomeric dampers in the VCS were obtained, measuring 11.1 mm and 10.0 mm, respectively.

Deciphering the crucial interactions among genes is one of the key issues in understanding the fundamental molecular and intracellular mechanisms of cell. Computational modeling of gene regulatory networks can be used as a powerful tool in various fields of molecular biomedicine such as identification of metabolic, regulator, and signal transduction pathways, analysis of complex genetic diseases, and drug discovery. In this paper, an optimal Boolean approach is proposed for computational modeling of gene regulatory networks from temporal gene expression profile. In this method, the optimal values of the Boolean thresholds of gene expression signals and the parameters of the interaction patterns between target and regulator genes are all designed as a mixed-integer nonlinear programming solved by Genetic Algorithm. To evaluate the performance of the proposed scheme, it has been applied to a well-known time course microarray data and gene regulatory network of Saccharomyces Cerevisiae from the literature. The reference network has 11 genes, 9 targets, and 61 regulatory interactions, and the original transcriptional dataset includes 18 timepoints for each gene expression signal. In this case study, the proposed computational model contains 142 unknown parameters that are optimally determined through optimization. The results demonstrate the efficiency of the proposed approach.

In this research, a pilot study and analysis of an innovative multi-channel photovoltaic/thermal (MCPV/T) system in a geographic location (35° 44' 35'' N, 50° 57' 25'' E) has been carried out. This system consists of integrating a photovoltaic panel and two PV/T heat-sink converters. The total electrical, exergy and energy efficiencies of the system at air flow rate of 0.005 kg/s and radiation intensity of 926 w/m2 were 9.73%, 10.72%, and 47.24%, respectively. An air flow rate of 0.011 kg/s and the radiation intensity of 927 w/m2 were also achieved to be  9.35%, 10.40% and 65.10%, respectively. Based on simulation results considering experiments validations, as the air flow rate increases, the overall energy efficiency increases to the maximal amount of 80%. However, the maximum exergy efficiency value has a local optimal point of 13.46% at a fluid flow rate of 0.024 kg/s. Similarly, with increasing channel heights, the total energy efficiency decreased to 70%, and the maximum exergy efficiency has a local optimal point of 13.64% at channel height of 0.011 m. As an overall achievement, the system has higher energy quality (exergy efficiency) in laminar flow regime and has higher energy efficiency under turbulent flow conditions.