Peristaltic Pump Research Articles

Optimization design analysis on sodium chloride solution evaporative crystallization system driven by high-temperature heat pump

Industrial crystallization is an essential procedure for food, chemistry, and seawater desalination, whereas it accompanies with considerable energy consumption. Although the mechanical vapor recompression serves as an effective tool for heat recovery, it cannot adapt to the lower evaporation temperatures of crystallization process (45–90 °C). To address the above issues, this paper proposed a composited system consisting of high-temperature heat pump and draft tube baffle evaporative crystallizer, which can achieve higher energy efficiency. The coupling mathematical model is solved through the Newton iterative method. The optimized input parameter is determined based on thermal analysis, and the coefficient of performance can reach 5.85. Moreover, the system employs R1234ze as the working medium, achieving the minimum total heat exchange area of 19.27 m2. Simultaneously, this system with different evaporation capacities exhibit similar cycle rates, approximately 58.3. After the system is constructed, the energy-saving and economic evaluation is performed. The result indicates that the system demonstrates an annual carbon dioxide emission reduction about 550 tons, an annual cost reduction of 221,718 CNY, and a dynamic payback period of only 0.89 years, presenting significant economic advantages. By this study, it provides some theoretical guidance for practical engineering applications.

Liquid Flow Control System Using Arduino Microcontroller

Abstract: An automated system presented here is designed to control the flow of fluid or liquid. The system uses automated peristaltic Pump to control the liquid flow. The peristaltic pump used here is designed and developed by the author according to the requirement of the application. The stepper motor movement of pump is controlled by using Arduino Microcontroller. Liquid flow through the pump is controlled in two ways: Automatic and manual mode. Such systems can be used in small industries for fluid separation from slurry or slug. Also can used where pre described amount of liquid or fluid is required in application.

Design of a Lab built Fully Automated Microfluidic Fluorometric System for Fluorescent Dye Applications

Microfluidics can process small amounts of fluids by using microscopic channels with microscale dimensions ranging from tens to hundreds of micrometers. Many researchers have recently been working on smaller analytical equipment, such as micro-flow cytometers. These gadgets offer numerous advantages, including portability, low cost, and low power consumption. It can also be integrated with other microfluidic devices for multitasking applications. In this study, the fluorescein dye was estimated using a lab-builtfully automated microfluidic fluorometric system. The developed system contained a microfluidic chip with two lines, each four centimetres long and with a volume of 15 μL. In this setup, two Arduino UNO (R3 version) microcontrollers were programmed using homebrew software. The first was to manage the two improvised peristaltic pumps, which successfully introduced the fluorescein dye to the water stream automatically, replacing the manual injection. The volume of the fluorescein sample was modified by varying the fluorescein line's run time. The second one was utilized to record the output signal. The method accurately identified fluorescein concentrations up to 0.01 μg/mL and 0.999 as a regression coefficient for six points. The RSD% (Relative Standard Deviation) for ten 0.08 μg/mL fluorescein measurements was 0%, and the detection limit was 1x10-4 μg/mL. The suggested method can measure 300 samples per hour while decreasing the amounts of reagents and waste. This microfluidic fluorometric system has the potential to be used for fluorescent dye assays in a variety of applications.

Operating principles of peristaltic pumping through a dense array of valves

Operating principles of peristaltic pumping through a dense array of valves

Magnetic polyurethane based composites as contactless valves in microfluidic applications

Magnetoactive polymer composites have garnered significant attention for their potential use in diverse applications, owing to their rapid and reversible response to external magnetic fields. By incorporating magnetic nanoparticles (MNPs) into an elastomeric matrix, these composites exhibit unique properties under static or alternating magnetic fields. In this context, thermo-polyurethane-based magnetic active composites are promising materials for developing microfluidic system components such as valves and peristaltic pumps. In the current study, we investigated the utilization of cobalt ferrite (CoFe2O4) magnetic nanoparticles in conjunction with a non-toxic synthesis method for polyurethane. It was explored the impact, on the overall success of the process, of cobalt ferrite nanoparticles incorporation at various stages of the thermo-polyurethane (TPU) synthesis reaction. Finally, the effects of different amounts of MNPs on the physicochemical properties of the resulting composites and their behavior as actuators under the influence of a magnetic field, was investigated. Our studies reveal that the actuator response of the composites increases proportionally with the percentage of MNPs present.Finally, the performance of a TPU/7.5% (V/V) CoFe2O4 composite strip as a flow control actuator within a microfluidic system was evaluated. This actuator responds to magnetic fields by bending, resulting in a 10% reduction in flow rate of microfluidic system. Reversing the magnetic field restores the flow rate to its initial value. Our cyclic tests illustrate the actuator's capacity to locally and temporarily modulate the microfluidic system's resistance. When combined with tailored TPU elasticity, these materials show significant potential for the fabrication of microfluidic valves and pumps.

Experimental study on convection heat transfer properties in rough-walled fractures of granite: The effect of fracture roughness

The fracture-dominated convection heat transfer behavior is commonly involved in the development, utilization and storage of thermal energy in fractured rock engineering. An experimental system assembled by a peristaltic pump drive, a liquid preheater and an electric blast drying oven is developed to quantify the effect of fracture roughness on the convection heat transfer characteristics. The overall heat transfer coefficient (OHTC) and the amount of heat transfer quantity from six fracture samples with different inlet temperatures and flow rates are calculated by the data acquisition at five observation points. In general, the average convective heat transfer efficiency between water and rock decreases gradually with time, and then enters a stage of thermal equilibrium while the temperatures at the five observation points become constant. The increasing flow rate can lead to the gradual increase of the OHTC and the slowdown of its growth rate. The OHTC is negatively correlated with the inlet temperature. With the increase of fracture surface roughness, the dominant flow effect is significantly enhanced, which leads to the weakening of heat transfer characteristics and the gradual reduction of OHTC. Finally, the heat transfer quantity decreases with the increase of roughness, and exists an inflection point with the flow rate.

Numerical analysis of high vacuum packaging efficiency for narrow structured devices

High vacuum packaging is the key manufacturing technology of passive vacuum devices. The inherent characteristics of narrow and long space and large surface-to-volume ratio make it challenging to effectively remove the desorption gas inside the device. To this end, the pressure distribution of two standard packaging methods during the pump-down process is investigated using the two-dimensional diffusion equation. Experiments and simulations show that a pressure gradient persists within the slit even when pumping reaches the quasi-equilibrium state. In addition, a Monte Carlo method based on the cosine law reveals that the high-frequency collisions of gas molecules with the walls impede the pumping process. Furthermore, the results indicate that for tube pumping, the number of collisions of gas molecules with the wall during transport within the gap is inversely proportional to the gap height. For edge pumping, the number of collisions is inversely proportional to the square of the gap height. This provides a theoretical basis for efficient high vacuum packaging and long-term pressure maintenance for passive vacuum devices.

Improvement of the installation for obtaining microcapsules

This article considers obtaining microcapsules using the spraying method by enhancing the device. To enhance the device, the peristaltic pump, peristaltic pump drive motor, and filter were replaced. The replaced components were substituted with a circulation pump, nozzle, and jikler. For the jikler experiments, solutions were prepared at concentrations of 0.5% and 1% alginate. At a concentration of 0.5% alginate, the capsules obtained by spraying were soft, irregularly shaped, with an average diameter of 2.0×10-3 m due to their low viscosity. At a concentration of 1% alginate, the capsules obtained by the drip method were spherical, with correct shapes, and solid, with an average diameter of 4.90×10-3 m due to their high viscosity. For experiments with a nozzle, solutions were prepared at concentrations of 0.5% and 1% alginate. At a concentration of 0.5% alginate, the capsules obtained by spraying were soft, irregularly shaped, with an average diameter of 2.56×10-3 m due to their low viscosity. At a concentration of 1% alginate, the capsules obtained by the drip method were uniformly round and dense, with an average size of 3.34×10-3 m due to their high viscosity.

Robust superhydrophobic Fe3O4/PAN/PBA nanofibrous aerogel with photo/magneto-thermal properties for efficient all-weather cleanup of viscous crude oil spills

Developing efficient absorbents for the cleanup of highly viscous crude oil spills is of critical importance. The current light-to-heat/electric-to-heat methods to reduce the viscosity of crude oil were limited by the complicated preparationprocesses, weather conditions and potential risk of electrical leakage. Here, a robust superhydrophobic composite Fe3O4/PAN/PBA nanofibrous aerogel (NFA) with excellent photo/magneto-thermal performance for efficient all-weather viscous crude oil spill remediation was fabricated by integrating facile blend electrospinning and freeze-drying techniques. Due to its superhydrophobicity/superoleophilicity (water contact angle of 151.3° and oil contact angle of 0°) and anisotropic microchannelstructure, the composite NFA exhibited rapid adsorption kinetics and ultra-high absorption capacity (54.4 − 97.1 g/g) toward various low-viscosity oils and organic solvents. Meanwhile, it displayed outstanding mechanical recyclability (84.07 % recovery after 200 cycles at 80 % strain) and reusability (86.74 % of theinitial capacity after 10 absorption-squeezing cycles). Notably, the composite NFA also showed excellent photo/magneto-thermal conversion efficiency, allowing it to achieve continuous and efficient cleanup ofcrude oil (recovery rate of 6.67 x103 kg m−3h−1) via peristaltic pumping. Therefore, this material holds great potential for all-weather cleanup of crude oil spills.

Experimental studies of the characteristics of a resonant leader emitter with a single-pass amplifier

The results of experimental studies of the energy and spatial characteristics of the lidar transmitter, built according to the generator-amplifier scheme based on an organic dye with tube pumping, are presented. The choice of a single-pass traveling wave amplifier used in the experiments was determined by preserving the spectral purity of the radiation. When constructing a lidar emitter according to the generator-amplifier scheme under conditions of constant pumping density, the problem arises of choosing the ratio between the length of the active element of the generator and the length of the active medium of the traveling wave amplifier, which would ensure the maximum efficiency of the entire emitter. The main task of the work was the experimental verification of the results of theoretical studies of the narrow-band emitter of the resonant lidar in order to determine the factors affecting the choice of the ratio of the lengths of the active elements of the generator and the amplifier based on the organic dye rhodamine 6Zh with tube pumping with limited total length. The amount of effective radiated energy was used as the main criterion for evaluating the efficiency of the generator-amplifier system. The experimental results confirm the theoretical conclusions that there are optimal ratios of the lengths of the generator and the amplifier, at which the effective radiation energy is maximal. The limiting length of the amplifier and the energy of the emitter built according to the generator-amplifier circuit are limited by the increase in the intensity of the radiation amplified along the active element, as well as the increase in the intensity of the amplified noise.

Peristaltic flow under the effects of tilted magnetic field: enhancing heat transfer using graphene nanoparticles

ABSTRACT This study investigates the consequences of inclined magnetic field and thermal radiation on peristaltic transportation of nanofluid through a porous media. The nanoliquid is composed of graphene nanoparticles and water. Viscous dissipation, mixed convection, thermal radiation, Joule heating and gravity effects are also considered. Mathematical modeling is carried out under small Reynolds number and large wavelength approximations. Resulting system of equations is numerically solved through built-in command NDSolve through Mathematica. The purpose of this research is to investigate the impact of volume fraction of nanoparticles, phase difference, inclination angle of the applied magnetic field, geometry parameters, Hartmann, Darcy and Brinkman numbers on axial velocity, temperature profile, heat transfer rates at the boundaries, pressure gradient, and pressure rise per wavelength. Outcomes of this study reveal that the addition of graphene nanoparticles enhances heat transfer performance. Velocity profile reduces and temperature increases for greater Hartmann number. Moreover, higher values of Hartmann number enhance heat transfer performance and peristaltic pumping. The enhancement of Darcy number increases velocity, temperature, and pressure while decreasing the peristaltic pumping. Variation in thermal radiation parameter reduces the temperature profile. The rate of pumping and pressure gradient decreases on increasing Froude number.

In Vitro Investigation of Insulin Dynamics During 4 Hours of Simulated Cardiopulmonary Bypass.

Hyperglycemia is common in patients undergoing cardiovascular surgery with cardiopulmonary bypass. We hypothesize that intraoperative hyperglycemia may be, at least partially, attributable to insulin loss due to adhesion on artificial surfaces and/or degradation by hemolysis. Thus, our primary aim was to investigate the loss of insulin in 2 different isolated extracorporeal circulation circuits (ECCs), that is, a conventional ECC (cECC) with a roller pump, and a mini-ECC (MiECC) system with a centrifugal pump. The secondary aim was to assess and compare the relationship between changes in insulin concentration and the degree of hemolysis in our 2 ECC models. Six cECC and 6 MiECC systems were primed with red packed blood cells and thawed fresh-frozen plasma (1:1). Four additional experiments were performed in cECC using only thawed fresh-frozen plasma. Human insulin (Actrapid) was added, targeting a plasma insulin concentration of 400 mU/L. Insulin concentration and hemolysis index were measured at baseline and hourly thereafter. The end points were the change in insulin level after 4 hours compared to baseline and hemolysis index after 4 hours. The insulin concentration and hemolysis index were analyzed by means of a saturated linear mixed-effect regression model with a random offset for each experiment to account for the repeated measure design of the study, resulting in mean estimates and 95% confidence intervals (CIs) of the primary end points as well as of pairwise contrasts with respect to ECC type. Insulin concentration decreased by 63% (95% CI, 48%-77%) in the MiECC and 92% (95% CI, 77%-106%) in the cECC system that contained red blood cells. Insulin loss was significantly higher in the cECC system compared to the MiECC (P = .022). In the cECC with only plasma, insulin did not significantly decrease (-4%; 95% CI, -21% to 14%). Hemolysis index in MiECC increased from 68 (95% CI, 46-91) to 76 (95% CI, 54-98) after 4 hours, in cECC from 81 (95% CI, 59-103) to 121 (95% CI, 99-143). Hemolysis index and percent change of insulin showed an excellent relationship (r = -0.99, P < .01). Our data showed that insulin levels substantially decreased during 4 hours of simulated cardiopulmonary bypass only in the ECC that contained hemoglobin. The decrease was more pronounced in the cECC, which also exhibited a greater degree of hemolysis. Our results suggest that insulin degradation by hemolysis products may be a stronger contributor to insulin loss than adhesion of insulin molecules to circuit surfaces.

Prediction and design optimization of mechanical properties for rubber fertilizer hose reinforced with helically wrapped nylon

Predicting and optimizing the mechanical performance of the helically wound nylon-reinforced rubber fertilizer hose (HWNR hose) is crucial for enhancing the performance of hose pumps. This study aims to enhance the service life of HWNR hoses and the efficiency of liquid fertilizer transport. First, a finite element simulation model and a mathematical model were established to analyze the influence of fiber layer arrangement on the maximum shear strain on the coaxial surface (MSS) and the reaction force on the extrusion roller (RF). For the first time, the Crested Porcupine Optimizer algorithm was used to improve the Generalized Regression Neural Network (CPO-GRNN) method to establish a surrogate model for predicting the mechanical properties of HWNR hoses, and it was compared with Response Surface Methodology (RSM). Results showed CPO-GRNN's superiority in handling complex nonlinear problems. Finally, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was employed for optimization design. Compared to the original HWNR hose with an MSS of 0.906 and an RF of 30,376N, the optimized design reduced the MSS by 7.99% and increased the RF by 2.46%, significantly enhancing their service life and liquid fertilizer transport capacity. However, further research on fatigue damage is needed.

Evaluation the kill rate and mutant selection window of danofloxacin against Actinobacillus pleuropneumoniae in a peristaltic pump model

BackgroundActinobacillus pleuropneumoniae is a serious pathogen in pigs. The abundant application of antibiotics has resulted in the gradual emergence of drugresistant bacteria, which has seriously affected treatment of disease. To aid measures to prevent the emergence and spread of drug-resistant bacteria, herein, the kill rate and mutant selection window (MSW) of danofloxacin (DAN) against A. pleuropneumoniae were evaluated.MethodsFor the kill rate study, the minimum inhibitory concentration (MIC) was tested using the micro dilution broth method and time-killing curves of DAN against A. pleuropneumoniae grown in tryptic soy broth (TSB) at a series drug concentrations (from 0 to 64 MIC) were constructed. The relationships between the kill rate and drug concentrations were analyzed using a Sigmoid Emax model during different time periods. For the MSW study, the MIC99 (the lowest concentration that inhibited the growth of the bacteria by ≥ 99%) and mutant prevention concentration (MPC) of DAN against A. pleuropneumoniae were measured using the agar plate method. Then, a peristaltic pump infection model was established to simulate the dynamic changes of DAN concentrations in pig lungs. The changes in number and sensitivity of A. pleuropneumoniae were measured. The relationships between pharmacokinetic/pharmacodynamic parameters and the antibacterial effect were analyzed using the Sigmoid Emax model.ResultsIn kill rate study, the MIC of DAN against A. pleuropneumoniae was 0.016 µg/mL. According to the kill rate, DAN exhibited concentration-dependent antibacterial activity against A. pleuropneumoniae. A bactericidal effect was observed when the DAN concentration reached 4–8 MIC. The kill rate increased constantly with the increase in DAN concentration, with a maximum value of 3.23 Log10 colony forming units (CFU)/mL/h during the 0–1 h period. When the drug concentration was in the middle part of the MSW, drugresistant bacteria might be induced. Therefore, the dosage should be avoided to produce a mean value of AUC24h/MIC99 (between 31.29 and 62.59 h. The values of AUC24h/MIC99 to achieve bacteriostatic, bactericidal, and eradication effects were 9.46, 25.14, and > 62.59 h, respectively.ConclusionThese kill rate and MSW results will provide valuable guidance for the use of DAN to treat A. pleuropneumoniae infections.

Perfusion Measures and Outcomes (PERForm) registry: First annual report.

The Perfusion Measures and Outcomes (PERForm) registry was established in 2010 to advance cardiopulmonary bypass (CPB) practices and outcomes. The registry is maintained through the Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative and is the official registry of the American Society of Extracorporeal Technology. This first annual PERForm registry report summarizes patient characteristics as well as CPB-related practice patterns in adult (≥18 years of age) patients between 2019 and 2022 from 42 participating hospitals. Data from PERForm are probabilistically matched to institutional surgical registry data. Trends in myocardial protection, glucose, anticoagulation, temperature, anemia (hematocrit), and fluid management are summarized. Additionally, trends in equipment (hardware/disposables) utilization and employed patient safety practices are reported. A total of 40,777 adult patients undergoing CPB were matched to institutional surgical registry data from 42 hospitals. Among these patients, 54.9% underwent a CABG procedure, 71.6% were male, and the median (IQR) age was 66.0 [58.0, 73.0] years. Overall, 33.1% of the CPB procedures utilized a roller pump for the arterial pump device, and a perfusion checklist was employed 99.6% of the time. The use of conventional ultrafiltration decreased over the study period (2019 vs. 2022; 27.1% vs. 24.9%) while the median (IQR) last hematocrit on CPB has remained stable [27.0 (24.0, 30.0) vs. 27.0 (24.0, 30.0)]. Pump sucker termination before protamine administration increased over the study period: (54.8% vs. 75.9%). Few robust clinical registries exist to collect data regarding the practice of CPB. Although data submitted to the PERForm registry demonstrate overall compliance with published perfusion evidence-based guidelines, noted opportunities to advance patient safety and outcomes remain.

IoT Enhanced Smart Aeroponics System

Abstract: Recently, urban farming has gained popularity as people become more aware of the quality of their food. Aeroponics is an urban farming technique that uses air as its growing medium. Compared to traditional farming and hydroponics, aeroponics offers a significant reduction in water usage while increasing yield. This study introduces an aeroponics system integrated with Internet of Things (IoT) technology for real-time and automated monitoring. The system maintains the pH level of the nutrient solution using a pH sensor and monitors temperature and humidity with an A DHT sensor. A peristaltic pump, coupled with a ultrasonic sensor, regulates the tank's liquid level. All these processes are accurately timed and shared on the ThingSpeak Platform and Blynk App for user interaction, facilitated by the ESP 32 Micro controller

Integrated analysis of electroosmotic and magnetohydrodynamic peristaltic pumping in physiological systems: Implications for biomedical applications

AbstractThe study of rheological properties in biological fluids, influenced by electroosmosis and magnetohydrodynamic (MHD) peristaltic mechanisms, plays a vital role in designing micro‐scale biomimetic pumping systems for targeted drug delivery. Considering these significant applications, the current study focuses on the integrated analysis of electroosmotic and magnetohydrodynamic peristaltic pumping of Williamson fluid within physiological systems with variable viscosity and thermal conductivity. The dimensional momentum equations are linearized under the approximation of lubrication theory. The current study deals with the impact of various physical parameters on flow, heat transfer, and pumping characteristics. These parameters include the magnetic parameter, variable viscosity, variable thermal conductivity, Helmholtz‐Smoluchowski velocity, and so on. It is noted from the current analysis that, Helmholtz‐Smoluchowski velocity and velocity slip parameters have decreasing effect on skin friction and Sherwood number. The electroosmotic and magnetic parameters contribute to larger trapped bolus sizes. These findings contribute significantly to advancing the development of efficient micro‐scale biomimetic pumping systems tailored for precise target drug delivery applications.

#1398 Linezolid adsorption during in vitro model of hemoadsorption with mini-module of HA380 cartridge

Abstract Background and Aims Septic shock is one of the most frequent causes in Intensive Care Unit (ICU) admission and is related to a very high risk of mortality. About one third of patients with sepsis develops acute kidney injury (AKI) which contributes to a worsening prognosis. AKI due to sepsis is the result of a dysregulated host immune response to infection, with the production of inflammatory mediators and cytokines that cause hemodynamic alterations, endothelial damage, apoptosis and, finally, immunoparalysis. The Jafron HA380 cartridge has been specifically designed for use in clinical conditions characterized by cytokine storm such as sepsis. Given the growing application of these hemoadsorption device in cases of septic AKI in ICU, an unsolved problem is whether these polymers adsorb drugs, including antibiotics. In vitro experiments were conducted to determine its adsorption capacity towards Linezolid (LZD) antibiotic. Method In vitro circulation was performed using a dedicated testing platform Galileo. A customized cartridge was built assembling mini-module components scaled in dimension towards HA380 and filled with 75 g of HA380 beads (25% of the regular size cartridge). Peristaltic pump was set at 250 mL/min. Four circulations were performed varying the initial mass of Linezolid in the tested solution (200, 400, 600, 1200 mg). Samples were collected after the first passage (FP) through the cartridge and every 5 or 10 minutes and Linezolid concentrations were measured. Adsorption was assessed considering the Removal Ratio (RR) and its kinetics. Results In vitro circulation confirms the affinity of beads material in binding Linezolid molecules. The kinetics shows an instantaneous and rapid adsorption in the very first part of the experiments. After that the adsorption rate decreases due to the decrease of antibiotic available in the solution. Among all the experiments, after the first passage of the solution through the cartridge, a RR higher than 70% has been achieved. After 100 passages of the solution into the cartridge, the adsorption reached about the 100% of RR. None of the amounts of Linezolid tested led to the cartridge saturation. A linear behavior between the mass injected in the solution and the mass adsorbed can be ascribable to the linear phase of Langmuir isotherm (see Fig.). Conclusion HA380 adsorbs significant amounts of Linezolid. The linear trend of the isotherm reveals a direct proportionality between binding sites of the sorbent material and the Linezolid tested. Further investigation using a higher quantity of Linezolid is necessary to reach the saturation of the cartridge and to understand the sorbent material capacity. These preliminary results highlight that there is an interaction that could affect the clinical outcome.

Hydrogeochemical and isotopic characterization of the main karst aquifers of the middle Valseriana (Northern Italy): Nossana and Ponte del Costone springs

Karst springs are one of the most exploited drinking water resources in the world. Isotopic and chemical analyses on these waters reveal essential insights into their hydrodynamics. Valseriana (Northern Italy) is a valley within the Italian Pre-Alps, characterized by high water availability. The main reasons are a bedrock consisting of very permeable carbonate formations and a mean annual precipitation above 1800 mm/y. In this context, the Valseriana spring catchments have become strategically important for the water exploitation and the domestic supply of Bergamo and the neighboring municipalities. This study general aim is to expand the knowledge on the two main karst systems (Nossana and Ponte del Costone), which together include twenty-three major and minor springs, by defining a state-of-the-art that will be useful in future decades to preserve this crucial resource. Specific objectives include i) verifying the applicability of the 3H/3He dating method in karst environments, ii) defining groups of springs according to their chemical and isotopic characteristics for possible safeguard actions, and iii) establishing a conceptual model of the internal dynamics of the two spring systems. A chemical and isotopic sampling campaign was specifically conducted between May 2018 and July 2019. A total of 34 water points were sampled, including natural springs, rivers, wells, karst caves, and nearby mines. Water sampling for 3H/3He isotopic analyses was proved possible through careful selection of the sampling points and the insertion of the pump tubing in the spring fractures. A first classification of springs into uniform hydrochemical groups was obtained by applying the hierarchical cluster analysis technique on major ions contents. These outputs were combined with information from the 3H/3He dating analyses and resulted in three different classes of springs. The three classes showed a clustering for elevations: at high, medium, and valley bottom elevations, respectively. Finally, the elaborations simplified the two karst systems by a hierarchical flow system model, dynamically controlled by different karst network development and infiltration water.

Impacts of activation energy and electroosmosis on peristaltic motion of micropolar Newtonian nanofluid inside a microchannel

This study investigates the impact of electroosmosis on the peristaltic flow of unsteady micropolar nanofluid with heat transfer. The findings could enhance the design of peristaltic pumps, potentially improving drug delivery systems, simulations of blood flow in medical devices, and cancer treatments. The fluid under investigation adheres to a micropolar model and flows through a microchannel that exhibits peristalsis along its walls. Moreover, the system is subjected to various external effects, including a uniform magnetic field, the electroosmotic phenomenon, heat absorption, and a chemical reaction with activation energy. Consequently, the problem is mathematically modulated by a system of nonlinear partial differential equations governing the velocity, temperature, and nanoparticle concentration. By employing wave transformation, these governing equations are reduced to ordinary differential equations (ODEs). The reduced equations were solved both analytically, using the homotopy perturbation method, and numerically, using the Runge–Kutta–Merson method. A comparison was made between the solutions, which were found to be closely aligned. Furthermore, a series of figures were employed to provide visual representation and discussion of the implications of the physical properties. The calculations reveal that the electroosmotic flow (EOF) enhances the axial flow of the micropolar fluid along the direction of the applied electric field. It is also observed that the increase in the activation energy (which indicates a low reaction rate) increases the concentration profile whereas the increase in the reaction rate parameter reduces the concentration profile. Additionally, the spin velocity of the particles is diminished by either an increase in the magnetic parameter or the coupling parameter.