s.k. gupta

Understanding hydraulic jumps in gradually expanding sloping channels is crucial for designing eco-friendly water management systems that minimize environmental impacts. This study seeks to investigate how the expansion ratio and channel slope together influence the characteristics of hydraulic jumps. The experiments were performed on four different channel slopes (00, 20, 40, and 60) and four distinct expansion ratios (B = b1/b2) of 0.35, 0.45, 0.55 and 0.75. The Reynolds number was ranged from 7150 to 27750, while the Froude number varied between 2.5 and 8.5 during the experiments. Novel correlations were developed to predict key hydraulic jump parameters, including depth ratio (d₂/d₁), relative energy loss (EL/E₁) and relative jump length (Lj/d₁), by considering the effects of expansion ratio, channel slope and Froude number. The results indicate that as the channel slope increased from 0° to 6°, the depth ratio and relative energy loss increased by approximately30.53% and 15.37%, respectively, while the relative jump length decreased by 11.11%. Conversely, as the expansion ratio decreased from 1.0 to 0.35, the depth ratio and relative jump length were reduced by approximately 9.63% and 10.42%, respectively; while the relative energy loss was increased by 24.21%.These findings highlight the significant influence of channel geometry on hydraulic jump characteristics, offering valuable insights for optimizing water conveyance structures. The proposed correlations provide a novel and intuitive approach to analyze hydraulic jumps in expanding sloping channels, addressing gaps in existing literature and contributing to sustainable water resource management.

The purpose of this study is to estimate PSD indirectly using a Radiation Dose Structured Report (RDSR) from Cath lab interventional procedures. The estimated dose was then compared with direct measurements using films.

Information on radiation exposure and dosage associated with a specific interventional radiology procedure is provided in the RDSR document. The RDSR produced by the machine was verified using slab phantom, Gafchromic XRV3 film, and Ray Safe X2 detector. The PSD is estimated by adding the intensely projected beam dose in acquisition mode with the fluoroscopic dose percentage obtained from the RDSR. During the procedure, Gafchromic films were used to measure PSD directly. Then, the estimated PSD was compared with the measured PSD.

The PSDmes and PSDcal in this study showed an average difference of 0.12 Gy (8%). The Wilcoxon Signed-Rank test has a p-value of 0.08 and the Spearman's rank correlation coefficient (rs) of 0.97 indicates a very strong positive correlation between the two variables.

The Statistical analysis shows that the estimation of PSD using RDSR is reliable for monitoring the patient. This method may help the cardiologist to follow up of the patients to give extra care to skin reactions. A safe standard work practice will certainly monitor the prevention of undesirable consequences of radiation.

The voltage stability margin (VSM) is an important indicator to access the voltage stability of the power system. In this paper, Flexible AC transmission systems (FACTS) devices like static synchronous compensator (STATCOM), static synchronous series compensator (SSSC), and unified power flow controller (UPFC) have been deployed to enhance the VSM of the power system. The placement of the FACTS devices is decided based on contingency raking. For the top five critical contingencies, the most severe bus is selected based on bus voltage stability criticality index and degree centrality methods. The critical line is decided based on the values of the line stability index, fast voltage stability index, and line stability factor. The STATCOM and shunt part of the UPFC are placed at the critical bus, whereas the SSSC and series part of the UPFC are placed at the critical line for enhancing voltage stability. The proposed method for voltage stability enhancement using FACTS devices is tested and validated on the IEEE-14 bus system and the NRPG-246 bus system at different system loading scenarios. The impact of the placement of FACTS devices is validated in terms of VSM improvement.

In the family of Flexible AC Transmission Systems (FACTS) controllers, the distributed power flow controller (DPFC) can control powerfully all the system's parameters like bus voltages magnitude, transmission angle, and line impedances with high redundancy and a wide range of compensation. In this paper, IEEE-14 bus IEEE-30 bus, and IEEE-118 bus systems are taken for the testing of the proposed approach. The optimal placement of the series and shunt converters of the DPFC is decided by the most critical bus and most critical line associated with that bus respectively. The sizing of the DPFC is decided based on the minimization of active power losses of the systems. The loss function is considered an objective function and the limits of the bus voltages magnitudes, bus voltage angles, thermal limits of the lines, and level of compensation of the DPFC are taken as the system's constraints. To solve complex problems in various fields, meta-heuristic optimizations are more popular. Among the meta-heuristic optimizers, the jellyfish optimizer is one that is based on the behavior of jellyfish in the ocean. The optimization of the objective function with constraints has been solved by time-varying acceleration coefficients (TVAC) particle swarm optimization (PSO), artificial bee colony (ABC), genetic algorithm (GA), and metaheuristic optimizer jellyfish methods. Results show that all the optimization techniques provide solutions with minimum losses. Among these methods, the solution of the jellyfish optimizer has the lowest active power losses, highest convergence rate, less number of iterations, and also takes less computational time.