Changes In Flow Rate Research Articles

Can online particle counters and electrochemical sensors distinguish normal periodic and aperiodic drinking water quality fluctuations from contamination?

Early warning systems monitoring the quality of drinking water need to distinguish between normal quality fluctuations and those caused by contaminants. Thus, to decrease the number of false positive events, normal water quality fluctuations, whether periodic or aperiodic, need to be characterized. For this, we used a novel flow-imaging particle counter, a light-scattering particle counter, and electrochemical sensors to monitor the drinking water quality of a pressure zone in a building complex for 109 days. Data were analyzed to determine the feasibility of the sensors and particle counters to distinguish periodic and aperiodic fluctuations from real-life contaminants. The concentrations of particles smaller than 10 μm and N, Small, Large, and B particles showed sudden changes recurring daily, likely due to the flow rate changes in the building complex. Conversely, the concentrations of larger than 10 μm particles and C particles, in addition to the responses of electrochemical sensors, remained in their low typical values despite flow rate changes. The aperiodic events, likely resulting from an abnormally high flow rate in the water mains due to maintenance, were detected using particle counters and electrochemical sensors. This study provides insights into choosing water quality sensors by showing that machine learning-based particle classes, such as B, C, F, and particles larger than 10 μm are promising in distinguishing contamination from aperiodic and periodic fluctuations while the use of other particle classes and electrochemical sensors may require dynamic baseline to decrease false positive events in an early warning system.

A prototype recuperated supercritical co2 cycle: Part-load and dynamic assessment

High efficiency, flexibility and competitive capital costs make supercritical CO2 (sCO2) systems a promising technology for renewable power generation in a low carbon energy scenario. Recently, innovative supercritical systems have been studied in the literature and proposed by DOE-NETL (STEP project) and by a few projects in the EU Horizon 2020 (H2020) program aiming to demonstrate supercritical CO2 Brayton power plants, promising superior techno-economic features than steam cycles particularly at high temperatures.The H2020 SOLARSCO2OL project, which started in 2020, is building the first European MW-scale sCO2 demonstration plant and has been specifically tailored for Concentrating Solar Power (CSP) applications. After a detailed explanation of the modelling approach for steady and unsteady cycle simulations, this paper presents the off-design and dynamic analysis of such plant layout, which is based on a simply recuperated sCO2 cycle. The entire system model has been developed in TRANSEO environment. The part-load analysis ranged from 50% of nominal up to a 105% peak load, discussing the impact on compressor and turbine operating conditions. Full operational envelop has been determined considering cycle main constraints, such as maximum turbine inlet temperature and minimum pressure at compressor inlet.The off-design performance analysis highlights the most relevant relationships among the main part-load regulating parameters, namely molten salt mass flow rate, CO2 mass flow rate, total CO2 mass in the loop, and shaft line speed. The results show specific features of different control approaches, discussing the pros and cons of each solution, considering also its upscale towards commercial applications. In particular, the analysis shows that at 51% of load an efficiency decrease of 20% is expected. Finally, the dynamic characterization of the closed loop shows the relatively fast responsiveness of the plant to compressor speed variations, causing quick changes in CO2 mass flow rate, together with longer time scale phenomena related to the plant heat exchangers. In this respect, sCO2 plants demonstrate to have the potential to provide primary reserve for the electrical grid, as far as thermal stresses on main plant components are kept under acceptable limits.

Nonlinear Modeling of an Automotive Air Conditioning System Considering Active Grille Shutters

This paper expands upon the state of the art in nonlinear modeling of automotive air conditioning systems. Prior models considered only the effects of the refrigerant compressor and the condenser fan. There are two new aspects included here. First, we create a mathematical model for front-end underhood airflow, considering vehicle speed, condenser fan rotational speed, and active grille shutter position. In addition, we present a new model for the power consumption of the vehicle associated with aerodynamic drag caused by underhood flow, as well as a fan power model which accounts not only for changes in rotational speed but also changes in flow rate. The models developed in this paper are coded in MATLAB/Simulink and assessed for various vehicle driving conditions against a higher-fidelity vehicle energy management model, showing good agreement. By including the active grille shutters as a controllable actuator and the impact of underhood flow on vehicle drag and fan power consumption, control schemes can be developed to holistically target reduced energy consumption for the air conditioning system and, thus, improve the overall vehicle energy efficiency.

Biomechanical study of the male lower urinary tract: Simulation of internal and external sphincters dyssynergia

Urethral sphincter dysfunction is an important cause of stress urinary incontinence (SUI). The most effective treatment is the insertion of an artificial urethral sphincter (AUS), which relies to a large extent on the surgeon’s experience. However, there is no quantitative standard for cuff tightness, resulting in frequent postoperative complications. This study aimed to investigate the effect of internal and external sphincter dyssynergia on urodynamic parameters in the lower urinary tract. A geometric model of male lower urinary tract tissue was constructed from collodion slices, accounting for the active behavior of the internal and external sphincters. Normal and dyssynergic internal and external sphincters (active sphincter behavior was individually injured by 25%, 50%, 75%, or 100%) were simulated with fluid–structure interactions and changes in urethral stress, displacement, and urine flow rate were detected. We found that when the internal sphincter was injured by 25%, 50%, 75%, and 100%, urethral stress near the internal sphincter decreased by 8.3%, 15.6%, 24.3%, and 35.7%, respectively. Additionally, when the external sphincter was injured by 25%, 50%, 75%, and 100%, urethral stress near the external sphincter was reduced by 13.3%, 24.3%, 38.6%, and 46.6%, respectively. Internal sphincter injury primarily affects positions near the internal sphincter and prostate, while external sphincter injury affects the area between the prostate and urethral outlet. These data could facilitate the standardized evaluation of internal and external sphincter dysfunction and lead to novel methods of preoperative assessment for AUS surgery.

Analysis of ozone generation in a planar atmospheric pressure air dielectric barrier discharge reactor

This work investigates O3 production in a planar atmospheric pressure air dielectric barrier discharge reactor numerically and experimentally. The surface temperature of the reactor is measured by an infrared (IR) thermal imager, and the O3 densities of cases in the reactive zone are measured by ultraviolet absorption spectroscopy. The 1.5D plasma fluid model (PFM) with transverse convection is employed to capture the average properties of a single microdischarge (MD) generated in the reactor. The concept of equivalent reaction is proposed to calculate spatial-cyclic average species sources obtained by the 1.5D PFM and provided to the chemical model of a 3D gas flow model (GFM) for obtaining density distributions of reactive species generated by MDs in the reactive zone. The simulated temperature distribution of the reactor surface is validated by that measured with the IR thermal imager since the gas temperature was reported as a critical discharge parameter for O3 generation. The simulated O3 densities show the same trend as the flow rate changes, which demonstrates the proposed model captures the average discharge dynamics in different operating conditions. In the 1.5D PFM, the simulated results show that the O3 molecules produced in the case of 4 SLM are much more than those produced in the case of 1 SLM though the O atoms produced in the case of 1 SLM are around 20% more than those produced in the case of 4 SLM. In the case of 1 SLM, more than 48% of O3 molecular generated are destructed, while only around 14% of O3 molecules are destructed in the case of 4 SLM. The analysis shows that around 73% of O atoms generated in the 1.5D PFM are consumed in the formation of O3 molecules in the case of 4 SLM, while only 18% of O atoms generated in the case of 1 SLM are consumed in the formation of O3 molecules. In the 3D GFM, the O3 destructed is around 24% of that destructed in the 1.5D PFM in the case of 4 SLM due to the oxidation reaction of NO, while only 11% of O3 molecules destructed as that destructed in the 1.5D PFM in the case of 1 SLM. The amounts of O3 molecules generated in the 3D GFM are minor if they are compared with those generated in the 1.5D PFM in all cases. The overall O3 yield efficiency reaches 97 g kWh−1 with the O3 concentration increasing up to 2700 ppm in the case of 4 SLM, while the O3 yield efficiency decreases to 10 g kWh−1 and O3 concentration drops to 1400 ppm in the case of 1 SLM.

Peristaltic mechanism in a micro wavy channel

In this article the peristaltic transport of Williamson fluid in a wavy microchannel has been discussed. Williamson fluid has number of applications in petroleum industry and power engineering. In order to determine the energy distribution, viscous dissipation is reckoned. Here we have considerd the wavelength of the wall motion much larger than the channel width to validate the theory of lubrication. For simplification of Poisson Boltzmann equation, we have applied the Debye-Hunkel linearization which is valid for small surface potential situations with zeta wall potential ≤ 25 mV. In the cases of large surface potentials, it has been found that, in comparison with the exact solution of the Poisson-Boltzmann equation, the linear solution predicts slightly lower values of the potential in the region near the wall. After a small distance from the wall, the difference between the linear solution and the exact solution diminishes. We have considered the Williamson fluid in the absence of body force. However, an external electric field has been employed. The solution of axial velocity, flow rate, pressure rise, heat transfer, mass concentration and stream functions subjected to physical partial slip boundary conditions are calculated. The effects of appropriate parameters like Debye length, Helmholtz-velocity which characterize the EDL phenomenon and external electric field are also examined. The results reveal that the peristaltic pumping varies by applying external electric field. The resulting non-linear problem has been solved analytically through the perturbation technique to analyze the distribution and change in velocity, temperature, pressure, concentration and volumetric flow rate. Results have been found through MATHEMATICA and the effects of important parameters have been discussed graphically.

Bedside visualisation tool for prediction of deviation from intended dosage in multi-infusion therapy.

In multi-infusion therapy, multiple infusion pumps are connected to one single vascular access point. Interaction between pressure changes from different pumps may result in temporary dosing errors, which can be very harmful to the patient. It is known that these dosing errors occur. However, clinicians tend to find it hard to estimate the order of magnitude of these errors. This research uses an existing mathematical model to create a bedside prediction tool that is able to provide clinicians with the dosing errors that will occur after flow rate changes in multi-infusion therapy. A panel of clinicians, consisting of both nurses and doctors, was formed, and, in order to assess the level of knowledge about dosing errors in multi-infusion, the panel was presented with four medication schedules in which a syringe exchange or change in flow rate took place. The panel was asked to predict the resulting dosing errors. A prediction tool was developed that describes a two pump multi-infusion system and predicts dosing errors resulting from changing the flow rate at one pump. 44% of the panel members wrongly predicted the impact of changing the set flow of liquid A on the flow of liquid B that reaches the patient. Nobody was able to correctly predict the dosing deviation if a very small catheter was used. After the prediction tool was shown, the clinicians indicated they had a improved understanding of what deviations to expect and that the tool would be useful in understanding multi-infusion dosing errors. Using the predictive tool to visualise the deviations from the set flow rate is an effective method to allow clinicians to gain insight in dosing errors in multi-infusion therapy. This knowledge can be used to better anticipate future dosing errors in clinical situations.

Streamflow trends of the Pyrenees using observations and multi-model approach (1980–2013)

Study regionThe Pyrenees. Study focusThe Pyrenees is sensitive to changes in climate (both natural and of anthropic origin) and changes in land use and cover (LULC). These changes can influence the water resources. The historical evolution (1980–2013) of the stream flows are studied using observed time series from non-influenced gauging stations and two models (SASER and SWAT). Their comparison helps to detect and analyze changes in flow rates and their trends (trends are computed using the Sen's slope estimator, the significance of which was evaluated using the Mann-Kendall test). Furthermore, it also allows to explore the question of attribution (these models do not simulate LULC change). New hydrological insights for the regionA complex and diverse domain such as the Pyrenees gives large differences between modelled trends revealing a large uncertainty that has been observed thanks to the use of two models. For the study period, mostly there are no significant trends. When trends are present in the observations and are also simulated, they are attributed to the effects of climate (natural variability and human induced climate change). When the significant trends observed are not simulated by the models, they are mainly attributed to changes in LULC. In general, models have difficulties detecting observed trends, leading to their attribution to changes in LULCs rather than climate, but there are some notable exceptions.

Studies of water flow parameters in the pipeline of wide-reach sprinklers

Optimization of the pipeline design of wide-span sprinklers and the parameters of the water flow in it can significantly reduce the material consumption and cost of the entire machine, save water and electricity. The purpose of the research is to simulate the flow of water in the pipeline of wide-reach sprinklers, to develop a methodology for optimizing the design parameters of the pipeline and the placement of drainage pipes for sprinklers. As a result of the research, dependences of flow rate changes along the pipeline were obtained, taking into account discreteness, pressure loss. The condition for obtaining identical jets from all taps for sprinklers is presented. A comparison of the results of theoretical and experimental studies confirms the reliability and validity of the use of the theory with uniform disconnection of the flow rate for the calculations of the pipeline of sprinklers, taking into account the introduced discreteness parameter, taking into account the number and location of taps for sprinklers. The presented technique was used in the design of sprinkler machines "Kuban-LK1M" (CASCADE) and CASCADE (Saratov, LLC "Reclamation machines").

Characteristics of medication-induced xerostomia and effect of treatment.

Side-effects of medications cause xerostomia. There have been cases where a medication has been discontinued owing to its severe side-effects. Therefore, the xerostomia must be treated to ensure that the primary disease is managed effectively. This study analyzed the actual status of patients with medication-induced xerostomia and investigates factors associated with its improvement. This study assessed 490 patients diagnosed with medication-induced xerostomia who had an unstimulated salivary flow of ≤0.1 mL/min and received treatment for xerostomia at a xerostomia clinic. Patient age, sex, medical history, medications used, disease duration of xerostomia, and psychological disorders were recorded. The anticholinergic burden was assessed using the Anticholinergic Cognitive Burden scale. The unstimulated salivary flow was measured by the spitting method. According to their symptoms and diagnoses, the patients were introduced to oral lubricants, instructed on how to perform massage, and prescribed Japanese herbal medicines, and sialogogues. Factors associated with the subjective improvement of xerostomia and objective changes in the salivary flow rate were recorded at six months. Xerostomia improved in 338 patients (75.3%). The improvement rate was significantly lower in patients with psychiatric disorders (63.6%) (P = 0.009). The improvement rate decreased as more anticholinergics were used (P = 0.018). However, xerostomia improved in approximately 60% of patients receiving three or more anticholinergics. The unstimulated salivary flow increased significantly more in patients who reported an improvement of xerostomia (0.033±0.053 mL/min) than in those who reported no improvement (0.013±0.02 mL/min) (P = 0.025). Xerostomia treatment improved oral dryness in 75.3% of patients receiving xerogenic medications in this study. If xerostomia due to side-effects of medications can be improved by treatment, it will greatly contribute to the quality of life of patients with xerogenic medications and may reduce the number of patients who discontinue medications.

Novel temperature-control strategy for single column side-stream extractive distillation process with intermediate-boiling entrainer

A simple, novel, and energy-saving single column side-stream extractive distillation (SSED) process was recently proposed in literature, for separating the azeotropic mixture of methanol (MeOH) and toluene (TOL) using triethylamine (Et3N) as an intermediate boiling entrainer. However, within the limited progress regarding the control of this process, composition controllers were required to maintain stringent product specifications in the face of disturbances. In view of this, our work firstly uncovers the feasibility of establishing control strategies without using composition loops. The research scope also covers the revision of thermodynamic properties in between MeOH and Et3N, re-design of the process with systematic optimization, development and evaluation of four control schemes. With thorough analyses, a dual-temperature control structure with three measurement (i.e. a side-stream temperature control loop, and a temperature difference control loop in the extractive section of the SSED column) was found to satisfactorily reject the specified feed disturbances (i.e. ±20% change in flowrate and composition). Notably, the loop adjusting the makeup flowrate to control the side stream temperature, which has not been proposed to the single column SSED process, greatly reduced the settling time under disturbances. Comparing with other control structures in literature, the one proposed in this work provides good control performances, but in a manner that is more industrially maneuverable.

A comprehensive method for determining the dewaxing interval period in gas lift wells

The gas lift method is an artificial lift method of well production using the energy of compressed gas injected into the well to lift the reservoir fluid to the surface. The formation of paraffin deposits has remained one of the critical oil production problems due to the growing percentage of hard-to-recover reserves in the overall structure. This complication is also typical for many oil and gas fields in Vietnam, such as the White Tiger, White Bear, and Dragon fields. Wax deposit formation negatively affects the operation of individual production wells and the development of the field as a whole, which leads to a decrease in productivity and the need to take measures to remove paraffin deposits, subsequently increasing the downtime period of the well. In order to ensure stable production of highly paraffinic oil, it is necessary to take measures to dewax wells systematically. The frequency of wax removal operations depends on the intensity of the wax formation, which is determined by various technological, technical, and geological factors. The interval between dewaxing operations is called the dewaxing interval period (DIP). This value is an important technological parameter and characterizes the efficiency of a well’s operation. In this study, a comprehensive method has been developed to determine the dewaxing interval period (treatment interval) for gas-lift wells when the formation of wax deposits has occurred. The optimal dewaxing interval period is suggested to be determined by the change in the liquid well flow rate at the point when it falls by 20% from the initial value. In addition, a mathematical model of the time-dependent wax thickness, taking into account the heat and mass transfer laws and the laboratory results using the Cold Finger method, has also been developed. The proposed model for determining the dewaxing interval period was applied to an oil well in Vietnam. The DIP prediction model gave a similar value to the actual DIP field data (6.67 and 6 days, respectively). The obtained results showed that the model had proven its accuracy following the results of a comparison with the field's data of dewaxing operations.

Numerical analysis of the internal flow and pressure pulsation characteristics of a submersible tubular electric pump device

In order to clarify the non-constant flow characteristics of the impeller and bulb body of the submersible tubular electric pump device, the entire flow rate conduit of the pump device is numerically calculated using the numerical simulation method, focusing on the analysis of the non-constant flow field characteristics of the guide vane body and bulb body and the time–frequency variation law of the pressure pulsation, and the results of the physical model testing confirm the validity of the numerical simulation. The findings demonstrate that the impeller of a submersible tubular electric pump is mostly responsible for the impeller’s inlet pressure pulsation, and the number of impeller blades to the number of peaks and valleys is consistent. Under the high flow rate condition of 1.2 Qd, the pressure fluctuation in the impeller inlet, between the impeller and the guide vane is small, and the main frequency is located at three times the rotational frequency, and the pressure pulsation at the outlet of the guide vane body has no obvious pattern and small amplitude. As the flow rate increases, the peak value of pressure pulsation at each monitoring point in the characteristic section of the pump device gradually decreases. The pressure pulsation peak value varies widely, ranging from 0.058 to 0.15, at each monitoring location of the impeller inlet. The peak value of pressure pulsation at each monitoring point of the impeller outlet fluctuates less due to the change of flow rate. The size and scale of the omega vortex structure in the guide vane body at different moments of the same cycle is small, and the number of vortex structures from the guide vane body inlet to the outlet direction shows a gradual increase in the trend; with a rise in flow rate, there is a tendency for the velocity and deflection angle of the guide vane body outlet and bulb body outlet surface to decrease.

Experimental studies on absorption-compression hybrid refrigeration system using 1,1,1,2-tetrafluoroethane/tetraethylene glycol dimethyl ether as working pair

The feasibility of combining novel halogenated hydrocarbon-based working pairs with low-pressure compression-assisted absorption refrigeration system (LCARS) was proved for the first time from the experimental perspective. An experimental prototype of the absorption-compression hybrid refrigeration system with a 1 kW cooling capacity was designed and tested to explore actual performances of selected R134a-DMETEG and performance improvements from compression in LCARS. At an evaporation temperature of approximately 5 °C, as the hot water inlet temperature and the solution flow rate change from 75 to 95 °C and 1.2–2.7 L/min, respectively, the coefficient of performance (COP) in the single-stage absorption refrigeration system (SSARS) varies from 0.211 to 0.412. At an increased evaporation temperature of approximately 10 °C, as the hot water inlet temperature and flow rate increase from 70 to 80 °C and 1.18–2.89 L/min, respectively, the COP in the SSARS varies from 0.238 to 0.552, while the COP in LCARS is improved and varies from 0.470 to 0.617. The LCARS increases the COP by a maximum of 91.04 % and can utilize a lower-grade heat source more efficiently due to its higher optimal COP at reduced hot water inlet temperatures. This study provided one feasible technical approach of combined use of R134a-DMETEG and LCARS to make up for the application limitations of traditional working pairs, contributing to application promotions of absorption systems, especially for the occasions with high requirement on safety and lightweight.

Влияние вида отвода и его расположения на энергетические характеристики и расчетный диаметр шнекового насоса

Results of numerical simulation of the inducer pump with axial and radial outlet are presented for the different axial position in the outlet. Influence of the inducer and the outlet position on hydraulic efficiency, pressure drop, power and design diameter with a change in flow rate is shown. Relevance of the work is caused by the lack of a unified theory for calculating freestanding and upstream inducer wheels in the aviation and space industries. An attempt was made to examine both freestanding and upstream inducer wheels and to show the effect of different wheel positioning on energy characteristics of one of the aircraft inducers. The study demonstrated that the radial outlet and the inducer position from the outlet had significant impact not only on the calculated wheel diameter and its energy characteristics, but also on the maximum flow rate.

Study on volume change of droplet

In infusion therapy, flow rate errors are caused by changes in the droplet volume dripped from drip chamber. The purpose of this study is to determine the change in droplet volume when surface tension, viscosity, density, and flow rate are varied. The droplet mass in a continuous drip is precisely measured and the droplet volume and standard deviation are determined for each 100 drops. At drip nozzle A, the rate of change in droplet volume was -44.78% at the change in surface tension, -12.14% at the change in viscosity, -5.70% at the change in density, and 8.14% at the change in flow rate. The volume change rate when double the surface tension, viscosity, and density were changed was 43.18% at the change in surface tension, -2.87% at the change in viscosity, and -16.10% at the change in density. The volume change rate affected by the viscosity change was slight. An experimental equation was tried to calculate the droplet volume of each condition. Since a change in surface tension causes a significant change in droplet volume, infusion therapy used drugs with significantly different surface tensions needs to pay attention to flow rate errors. It is recommended that the surface tension of drugs used for infusion is written on the package insert.

Establishment of resource-saving modes of irrigation pumps

The article presents the results of a study obtained in the process of testing the flow path of modernized centrifugal pumps. The authors proposed the device of new elements based on the calculation of the flow limited only by the side walls. The purpose of this work is to change and refine the calculations of the indicators of the modes of pumping units and the features of the performance of modern vane pumps. They are developed on the basis of the results of a large number of tests carried out by the authors of pump assemblies and operational surveys of irrigation pumping stations in Uzbekistan. The determination of the economically viable duration of the period of operation of pumping units, taking into account changes in energy characteristics and resource-saving operating technologies, was refined when measuring the efficiency of the upgraded pump D2000-100 under various operating modes. The creation of resource-saving methods of operation of pumping units that reduce or eliminate the intensity of cavitation-abrasive wear, including those based on taking into account changes in flow rates in the inter-blade channels of the impeller, is shown in the corresponding characteristics of the upgraded pump.

Optimal Safety-Critical Control of Epidemics

We present a generalized model for epidemic processes that partitions control into changes in linear and non-linear flow rates between compartments, respectively. We then define an optimal control problem that minimizes the weighted cost of rate control on the generalized model while maintaining conditions that guarantee system safety at any time using control barrier functions. Using this formulation, we prove that under homogeneous penalties the optimal controller will always favor increasing the linear flow out of an infectious process over reducing nonlinear flow in. Further, in the case of heterogeneous penalties, we provide necessary and sufficient conditions under which the optimal controller will set control of non-linear rates (i.e., the reduction of flow rate into the infection process) to zero. We then illustrate these results through the simulation of a bi-virus SEIQRS model.

Model-based Analysis of Nitrogen Dynamics in the Tigris River in Baghdad City

Developing a solid understanding of the nitrogen dynamics across the Tigris River is critical to evaluate the environmental degradation of the increased N fluxes. Nitrite, nitrate, and total oxidized N (nitrite+nitrate) were monitored from April 2018 to August 2019. Plug flow reactors and continuously stirred tank reactors in series models were implemented to explore N behavior in the river system. The results indicated that the total oxidized N decreased over the first half of the study period, then was followed by a high rate of nitrate production. These findings are also supported by changes of the river flow rates, dissolved oxygen, pH, and chemical oxygen demand. The models have the capacity to simulate N dynamics, with varied prediction errors. Root mean squared errors between measured and predicted nitrite, nitrate, and total oxidized N concentrations were 0.118, 2.595, and 2.560 g m-3, respectively, for the PFR model, while these values were 0.05, 0.175 g m-3, and 0.176 g m-3, respectively, for the CSTRS model. The correlation coefficients were 0.012, 0.925, and 0.922 for nitrite, nitrate, and total oxidized N, respectively, when the PFR model was applied. These values were 0.92, 0.99, and 0.99, respectively, after the application of the CSTRS model. Obtained results revealed that the modeling approach can provide a useful framework to improve understanding of N dynamics, which helps to develop mitigation strategies for sustaining water quality in the Tigris River.

Impact of Menopausal Duration on Salivary Flow Rate, Tooth Loss, and Oral Health-related Quality of Life in Indian Communities.

Diminishing hormonal levels after menopause evoke physiological changes in a woman's body. Their effects on the oral cavity are noteworthy, considering symptoms of dry mouth, altered taste perceptions, and tooth loss that may be attributed to reduced salivary flow and alveolar density changes. The purpose of this study was to assess changes in salivary flow rate, tooth loss, and oral health-related quality of life (OHRQoL) as menopausal duration increased. A total of 327 women fulfilling the eligibility criteria were chosen from two villages in the Mysuru district, Karnataka. They were categorized into three groups based on menopausal durations. Salivary flow rates, number of teeth lost, and OHRQoL after menopause were assessed and compared at different menopausal durations. Sociodemographic characteristics and oral hygiene practices were recorded to identify potential confounders. Multivariate analysis demonstrated a significant association between menopausal duration and salivary flow rates (adjusted odds ratio = 2.269). However, no such associations were observed with tooth loss and OHRQoL. Menopausal duration significantly affects salivary flow rate. Its influence on tooth loss and OHRQoL is, however, less evident. Although strong associations cannot be established, the inevitability of the menopausal state advocates consideration of other major yet modifiable factors to improve oral health.