Maximum Pressure Value Research Articles

Computational and experimental assessment of the influence of ultra-low pressure tires of mobile power equipment on soil

The article describes a method for determining the maximum pressures in contact of an ultra-low pressure tire with deformable soil: with low bearing capacity using the example of a thin-walled tire 1020x420-18 of the Bel-79 model. In the current practice of determining the effect of pneumatic tires on the soil, the method of determining the contact area of a tire on an undeformable flat bearing surface is used. By dividing the load on the tire by the obtained contact area, multiplied by correction factors, the maximum tire pressure on the soil is obtained. By comparing the maximum pressure obtained in the tire contact with the non-deformable bearing surface with the permissible pressure, the correspondence of tractor and agricultural tires to operating conditions on soils with a certain moisture and hardness is evaluated. But this method of assessment is unacceptable for tires of low and ultra-low pressure due to significant deformation of the tire and soil: in contact and, therefore, a larger contact area and lower values of maximum and average pressure on the soil. Therefore, the novelty of the work is an experimental assessment of the impact on the soil of tires of low and ultra-low pressure on deformable soil. The method includes the experimental determination of the dependence of tire and ground deformations on air pressure in a tire and load, as well as the dependence of the contact area sizes on deformable soil on tire and ground deformations. The contact areas and the coefficients of the uneven distribution of pressure in the contact according to the average values and shapes of the diagrams determine the maximum pressure in the contact of the tire with deformable soil. As a result, the curves of the dependences of maximum pressures in contact on air pressures and loads on deformable soil for low and ultra-low pressure tires were obtained for the first time. The dependences of maximum pressures in contact on air pressure at fixed loads can be a kind of passport for thin-walled tires, similar to the traction characteristics of tractor tires and the traction and speed characteristics of automobile tires. The results obtained make it possible to determine with high accuracy the operating conditions of high-traffic vehicles on low and ultra-low pressure tires.

An investigation on Piston structural analysis related with experimental cylinder pressures using different biodiesel blend ratios

The prime objective of this investigation is to ascertain the stress analysis of dissimilar pistons with different compression ratios. The diverse piston geometries of deep cylindrical piston (DCP) and shallow re-entrant piston (SRP) were exclusively designed by the baseline of hemispherical existing piston (HEP) at different compression ratios of 15:1, 17:1, and 16:1, respectively. The combustion characteristics of cylinder pressures were established for various piston geometries using different biodiesel blends of soya bean, rice bran, and pongamia. The engine operating characteristics and load capacity in terms of the pressure with respect to crank angle rotation, air and fuel mixing rate, and turning moments were attained from the experimental investigation. Analysis of piston geometry was done with boundary conditions of the maximum value of the cylinder pressure for pongamia biodiesel blends with diesel. The structural analysis of equivalent stress and total deformation values was plotted against the cylinder pressure values. This analysis predicts the portion of the piston structure that might be damaged on top or bottom skirt. Finally, mechanical thermal stresses developed in the piston were optimized with lesser deformation by finite element analysis (FEM).

572: Enhanced postpartum screening for hypertensive disorders of pregnancy associated with lower blood pressure at readmission

In 2013, ACOG recommended early outpatient follow-up for postpartum women with hypertension. The objective of this study was to determine if women presenting to the hospital after updated ACOG screening guidelines had a milder disease state than those presenting prior. We hypothesized an increase in the number of postpartum presentations due to increased surveillance after the guidelines, but that this cohort would have less severe disease. A retrospective cohort study of postpartum women who delivered at a tertiary care medical center from 2012-2018. Women were included who had a hypertensive disorder of pregnancy prior to discharge and presented to the hospital within 30 days of delivery with a hypertension-related complaint. Subjects were divided into the following cohorts: 1/1/2012 – 12/31/2013 Pre-guidelines (unexposed) and 7/1/2014 – 12/31/2018 Post-guidelines (exposed) with a 6-month intervening washout period. The primary outcome was maximum and mean blood pressure values at presentation. The secondary outcome was a composite of severe hypertensive morbidity. 143 women were analyzed comprising 149 unique hospital encounters. Pre- and post-guidelines groups were comparable, with the exception of higher proportion of vaginal deliveries post-guidelines (p=0.04). Maximum diastolic blood pressure (108.3 vs 100.4, p< 0.001) and mean diastolic blood pressure (89.8 vs 86.1, p=0.01) were significantly lower in women admitted after implementation of the guidelines. There was an increase in outpatient screening after implementation of the guidelines (64% vs 85%, p=0.05). There was no significant difference in composite severe hypertensive morbidity (p=0.41). In postpartum women with hypertensive disorders of pregnancy presenting to the hospital, mean and maximum diastolic blood pressures were significantly lower in those presenting after implementation of enhanced screening guidelines. This suggests early outpatient screening can identify women at risk of severe hypertension in the postpartum period.

Comparative Analysis of Combustion Stability of Diesel/Ethanol Utilization by Blend and Dual Fuel

The aim of the work is a comparison of two combustion systems of fuels with different reactivity. The first is combustion of the fuel mixture and the second is combustion in a dual-fuel engine. Diesel fuel was burned with pure ethanol. Both methods of co-firing fuels have both advantages and disadvantages. Attention was paid to the combustion stability aspect determined by COVIMEP as well as the probability density function of IMEP. It was analyzed also the spread of the maximum pressure value, the angle of the position of maximum pressure. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operated with ethanol up to 50% of its energy fraction.

Impact of fuel/oxidizer ratio of NaN3 and KNO3 airbag gas generants on toxic emission and performance

This paper reports the experimental methodology to arrive at an optimal weight composition of NaN3/KNO3 airbag gas generants based on thermal studies using Differential Scanning Calorimetry/Thermogravimetry analysis. The residual analysis showed that the fuel oxidizer mixture of 62.5/37.5 by weight percentage can be used as the optimal composition for airbag gas generants, as it produced minimum residues after decomposition reaction. Spectroscopic studies using SEM-EDS showed that the optimal composition had zero residues of toxic NaN3 compared to all other compositions tested. The heat energy released was found to be more in the air atmosphere due to the complete decomposition of mixtures compared to the nitrogen atmosphere. In this study, the ballistic properties such as time to peak pressure and peak pressure generated on ignition of the mixture were measured using the closed vessel test and the 28.3 lit full-fledged tank test. For the first time, the maximum pressure developed during decomposition of the fuel/oxidizer mixtures on the closed vessel test was compared with the theoretical maximum pressure value calculated using the ideal gas equation assuming that the process was adiabatic. The applicability of using the constant volume closed vessel test chamber for performance testing of auto airbag systems was also addressed.

Considerations on transients in a water supply distribution network

Lipnița is a village situated in a hilly region, in Constanta County. The water supply system has its own groundwater water source, placed in the middle of the village at a low elevation. Water is conveyed, by a long transmission duct to a storage tank from which it flows by gravity to the consumers. The distribution network has two long mains that intersect in a manifold with isolation valves, situated in the middle of the village. This topology of the system shows high static head for the transmission duct and high elevation differences between the end consumers and those in the centre of the village.The paper presents an analysis, by numerical simulation, on the transients that occur in two different segments of the system.The simulation was performed either for the original old steel made network, aiming at identifying the vulnerable cross sections and extreme pressure values. The results showed that maximal pressure values are not dangerous, but cavitation occurs along the pipeline. The same simulation was carried out for the new PEHD pipelines. The change of material and the increase in diameter of the new pipes showed better results regarding pressure variation during transients. Cavitation is avoided.

Modelling the stress-strain state of tubular springs in the ANSYS software package

The paper presents the results of calculating the stresses and strains of manometric tubular springs under loading by internal pressure and external force. For research, the finite element method implemented in the ANSYS program was used. The problems of constructing a grid model of the tubular element were solved, the displacements of the free end and stresses from internal pressure were determined, and the maximum permissible pressure value was found.

Evaluation of heat release and combustion analysis in spark ignition Wankel and reciprocating engine

In this study, a single-rotor multi side port Wankel research engine and a single cylinder spark ignition (SI) engine having three different type combustion chamber geometry (MR, Cylindrical bowl, Flat) were used. Engine experiments were performed at 2000 rpm, 3 bar and 5 bar bmep (brake mean effective pressure) and stoichiometric conditions. Combustion analysis was performed for Wankel and a reciprocating SI engine with three types combustion chamber geometries, which are not included in the literature.In the Wankel engine, the maximum pressure value was lower than the reciprocating SI engines and the maximum pressure obtained far away from the TDC. The reason of this is lower burning velocity and combustion progress toward the expansion stroke. Wankel engine's lower burning velocity also reduced the maximum temperature values. The normalized cumulative heat release rate was about 15% higher than the reciprocating SI engine with different combustion chambers. In Wankel engine, NO emissions are 15–45% lower due to the lower combustion temperatures. On the contrary, THC emissions were up to two times higher due to the combustion chamber geometry and absence of squish effect.The MR type combustion chamber has the highest combustion speed and pressure value due to the intense flow and mixture conditions. In the Wankel engine, combustion process is shifted toward the expansion phase, thus resulting to the lower thermal efficiency. In order to improve this process, additional precaution, such as different mixture formation and flow intensification methods in the combustion chamber are required.

Artificial neural network modeling and optimization of wheat starch suspension microfiltration using twisted tape as a turbulence promoter

The aim of this study was the modeling and optimization of the turbulence promoter-assisted starch suspension microfiltration process using artificial neural networks. The main aim was to analyze the influence of process parameters (transmembrane pressure, suspension flow rate, and concentration) on permeate flux (with and without twisted tape) and energy consumption in order to find the optimal combination of process parameters needed for the efficient use of the turbulence promoter. The obtained results showed a very good agreement between artificial neural network predictions and experimental data. Permeate flux was mostly influenced by suspension concentration, while the suspension flow rate had the highest impact on the reduction of the specific energy consumption. Performed optimization, using a genetic algorithm, indicated that microfiltration process should be carried out at the maximum value of transmembrane pressure (0.9 bar), at a suspension flow rate in the range from 80 to 93 L/hr, and at a suspension concentration of 5 g/L. Practical applications Practical application of this research presents the possibility for the wastewater treatment in the wheat starch processing industry that produces a significant amount of wastewater annually, mainly consisting of starch. Adequate treatment of wastewater can recover water-soluble and partly suspended substances from the raw material and at the same time, recycle and purify wastewater prior to releasing to the ecosystem. In the last decades, cross-flow microfiltration has shown many advantages in wastewater treatment operations comparing to conventional methods. In this research, cross-flow microfiltration with twisted tape, as a turbulence promoter, is chosen in order to achieve higher values of permeate flux, simultaneously, by paying attention on energy efficiency. The multi-response optimization, performed by applying the genetic algorithm, enables the determination of process parameters necessary for the accomplishment of economic and cost-effective microfiltration process.

Study on landfill gas migration in landfilled municipal solid waste based on gas–solid coupling model

AbstractGas migration rule is of great significance to the safe disposal of landfill. In this article, a gas–solid coupling model was developed and used to simulate the effects of various factors on gas migration. The simulation results showed that gas pressure in landfill decreased with the increase of extraction pressure, anisotropy ratio, coverage gas permeability, extraction well depth, and coverage thickness. The maximum value of gas pressure could reach 683 Pa. Among these factors, extraction pressure played the largest role in the gas pressure, while coverage thickness played the smallest role in it. The radius of influence (RoI) and gas flow rate increased with the increase of extraction pressure, refuse gas permeability, coverage thickness, and the extraction well depth, but with the decrease of coverage gas permeability. The effect of extraction well depth on RoI and gas flow rate was the most significant. When extraction well depth increased from 0.5 landfill height to 0.9 landfill height, the maximum values of RoI and extraction volume increased by 20 m and 20 m3/hr, respectively. It was suggested that the design of landfill gas (LFG) collection system should consider the influence of various factors in practical engineering.

Optimization Investigations of a Combined Binary-Cycle Geothermal Power Plant with Two Separation Pressures and Flashed Steam Superheating Using a Hydrogen–Oxygen Steam Generator

The article considers the specific features of and prospects for improving the efficiency of geothermal power plants (GeoPPs) that use a steam–water mixture from geothermal fields and steam superheating as an energy source. The process flow diagram of a combined binary-cycle GeoPP with two separation pressures and flashed steam superheating with the use of a hydrogen–oxygen steam generator is proposed. The advisability of using a separator downstream of the high-pressure section for decreasing the steam moisture at the turbine condenser inlet is substantiated. The article also presents the results from numerical optimization investigations of the effect that the choice of organic working fluid has on the efficiency, safety, and environmental characteristics of the binary installation used as part of a combined-cycle GeoPP. The following groups of organic substances as possible candidates for use as working fluid are considered: nontoxic, nonflammable, and nonexplosive ones (group I); low-toxic, nonflammable, and nonexplosive ones (group II); nontoxic inflammable ones (group III); and low-toxic, inflammable, and explosive ones (group IV). Typical dependences characterizing the effect that the pressure in the expander and the saturation pressure in the evaporator have on the binary turbine net power output, on the specific flowrate of separated geothermal brine per unit power capacity, on the binary cycle efficiency, and on the GeoPP efficiency as a whole are shown taking as examples the use of cyclobutane and octafluoropropane as a working fluid. For a few working fluids, the existence of extremes in the above-mentioned dependences is established, which determine the binary installation optimal power values and the minimal geothermal brine specific flowrate. Based on the numerical analysis results, limitations are imposed on the admissible maximum and minimum pressure values in the binary circuit. Bar charts of calculated process characteristics influencing the binary turbine flow path’s design and efficiency are plotted. A priority (according to the maximum net power output criterion) list of working fluids relating to the group of environmentally friendly organic substances for the combined-cycle GeoPP binary installation with flashed steam superheating taking into account process-related limitations is drawn up.

Effects of pilot diesel injection strategies on combustion and emission characteristics of dual-fuel engines at part load conditions

The high level of UHC and CO emissions and poor performance are the Achilles heel of the dual-fuel engines at part load condition. In this research, the KIVA-3V code has been used to simulate, and analyze the combustion process of a dual-fuel diesel engine at part loads. To resolve these problems, the effects of three injection strategies including single and split injection timing, and the number of injector nozzle holes have been investigated on engine combustion and emission characteristics. Results indicate that by advancing the baseline injection timing of the diesel fuel from −17 to −70 CAD ATDC, the maximum pressure value increases from 46 bars to 84.2 bars, UHC and CO emissions decrease 98% and 99%, respectively, and NOx emissions increase 339%. In the split injection, the optimum injection timings of pilot diesel fuel are −80 and −60 CAD ATDC for the first and second pulses. In addition, UHC and CO emissions decrease 98% and 99.9%, respectively. Finally, in the third strategy, with increasing injector nozzle holes, ignition and combustion start earlier, and the maximum pressure value, NOx and CO emissions increase, but UHC emissions decrease.

The influence of cavitation and the degree of overlap of the flow of cylindrical flow bodies on the flow pattern, hydrodynamic and spectral characteristics of a flat-type hydrodynamic generator

The paper presents the results of studies of flow behind cylindrical flow bodies in a flat-flow hydrodynamic generator, obtained on the hydrodynamic bench of the experimental base of the National Scientific Center NBMT RAS with the degree of flow blocking by flow bodies St/S0 = 10-80%, Re numbers (0,5-5) · 105, PVH inlet pressure = 0,1-0,8 MPa. It was found that with the same pressure drop two different types of flow can be realized behind the flow bodies: with a developed cavitation zone, within which there is an extensive low pressure area and without it, but with the formation of vortex structures with the presence of centers of cavitation bubbles in them. At a certain value of input to output pressure, which is constant for each value of the degree of overlap of the flow, powerful pressure peaks of the resonant type arise with an amplitude of 2-2,5 times the maximum value of the input pressure. The frequency of occurrence of these pressure peaks increases linearly with increasing pressure drop, and decreases by an order of magnitude with an increase in the degree of overlap of flow up to 80%. The frequency dependence of the number Re for each value of St/S0 is linear. The value of the Strouhal number St with an increase in St/S0 increases linearly with St/S0 = 0,82 and the value St = 1,2.

Impact of Pentanol Addition and Injection Timing on the Characteristics of a Single-Cylinder Diesel Engine

In this study, first, the effects of addition of 10% (Pen10), 20% (Pen20), and 30% (Pen30) pentanol on the performance, combustion, and emissions of a diesel engine were investigated. Then, the effect of injection timing for Pen30 fuel was investigated by changing the original injection timing of 20 to 22 and 24° BTDC (before top dead center). The engine tests were performed under different loads at 2400 rpm. The results indicated that, with the advancing of the diesel injection timing and increasing the pentanol ratio in the fuel blends, the ignition delay increased and the start of combustion delayed. The maximum heat release rate and cylinder pressure values of pentanol blends were found to be higher than those of diesel fuel. Both the maximum cylinder pressure and the maximum heat release rate increased with the advancing of the diesel injection timing to 22 and 24° BTDC. Brake-specific fuel consumption value of Pen30 was higher than that of diesel fuel at the original injection timing, and it decreased as the injection timing was advanced to 22 and 24° BTDC as compared to that of the original injection timing. NOx emission decreased with the increasing pentanol fraction. Also, NOx emissions increased significantly at 24° BTDC injection timing but decreased slightly at 22° BTDC injection timing. Smoke emissions of the pentanol blends are lower than those of the diesel fuel under all operating conditions as well as decreased with the advancing injection timing.

Mathematical modeling of the stress state of the tubular stand of the cultivator

The paper presents the results of the calculation of stresses and strains of the cultivator stand structure with a flexible tubular element under loading with internal pressure and external force. For research, we used the finite element method, implemented in the program “ANSYS”. The tasks of building a grid model of a tubular element were solved, the displacements of the free end and stresses under the action of internal pressure were determined, and the maximum allowable pressure value was found. The horizontal component of the impact force of the soil on the cultivator, at which buckling occurs, is determined, and the influence of the section shape on the characteristics of the cultivator stand is investigated.

Investigation of Contact Performance of Case-Hardened Gears Under Plasto-elastohydrodynamic Lubrication

Case-hardening is widely used to enhance gear loading capacity. Simulation of the material gradient properties and contact characteristics are the key issues in contact fatigue analysis of case-hardened gears. In this work, a plasto-elastohydrodynamic lubrication (PEHL) model incorporating the hardness gradient and surface roughness is developed to investigate the contact performance of case-hardened gears. The generalized Reynolds equation is solved to determine film thickness and contact pressure. The plastic deformation and residual stress are obtained via the half-space eigenstrain problem solving. The Dang Van multiaxial fatigue criterion and the Euler transformation are employed to evaluate the contact fatigue parameter based on the predetermined stress field. The discrete convolution and fast Fourier transform (DC-FFT) algorithm is used for accelerating the computation. The influences of effective case depth, surface hardness and surface roughness on the contact performance are investigated. Numerical results indicate that as the surface hardness increases, the probability of fatigue crack nucleation decreases, and the depth of the crack initiation site increases. For a lower surface roughness case, the maximum von Mises stress and equivalent plastic strain appear at a deeper layer. As the surface roughness increases, the maximum values of pressure and stress increase sharply and move closer to the surface.

Combustion stability of dual fuel engine powered by diesel-ethanol fuels

The paper presents result of combustion stability assessment of dual fuel engine. The authors analyzed results of co-combustion of diesel fuel with alcohol in terms of combustion stability. The comparative analysis of both the operational parameters of the engine and the IMEP, as the parameters determining the stability of the combustion process, were carried out. It was analyzed, among others values of the COVIMEP coefficient, the spread of the maximum pressure value, the angle of the position of maximum pressure and the probability density distribution of the IMEP. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operat-ed with ethanol up to 50% of its energy fraction. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. It turns out that the share of ethanol does not adversely affect the stability of ignition..

Static electronic baropodometry in patients with metatarsalgia

Objective: To analyze the values obtained by electronic baropodometry in patients with metatarsalgia. Methods: A retrospective observational study of medical data (gender, height, weight, body mass index, foot laterality, shoe size and clinical diagnosis) and values obtained by static electronic baropodometry (load distribution and maximum and mean pressure) was performed. A total of 39 patients with clinical complaints of metatarsalgia were selected and subjected to static electronic baropodometry. Results: Female gender was more prevalent (58.9%) among patients, and 61.53% of the patients were overweight or obese. The mean maximum pressure was 1.76kgf/cm2, and the forefoot-to rearfoot load distribution ratio was 0.86. There was a significant correlation between body mass index and maximum pressure. No correlation was found with shoe size. Conclusion: The baropodometry values measured in this study were similar to those reported in the literature. Obese and overweight patients had a higher maximum pressure value, which suggests a higher risk of metatarsal pain in this population. Level of Evidence III; Diagnostic Studies; Study of non consecutive patients; Without consistently applied reference “gold” standard.

Effect of distance between ignition location and window on indoor gas explosion development

Introduction. It has been previously known that for gas explosions in an unconfined chamber the following rule applies: the larger the distance between gas ignition location and relief opening (window), the higher the explosion pressure. This statement is based on results obtained by a number of researchers, including ourselves. However, as demonstrated by recent physical experiments, it is valid only for window sizes comparable to those recommended by guidelines to ensure certain safety conditions. For smaller window sizes, this relationship is leveled out or even changes its sign. Research objective is to determine the cause of inversed relationship between distance from the window to ignition location and explosion pressure. Tackling this objective is of scientific and practical importance. Research methods and tools. Two mathematical model variants for gas explosion development in an unconfined chamber were employed to study the revealed phenomenon, i. e. simplified model and numerical model. The first one, i. e. simplified model, is based on chamber representation as lumped volume, and using the Clapeyron equation in differential form. It was obtained that besides known factors, such as window size, properties of outflowing gases, etc., explosion development is influenced by the area of flame front and the time when it approaches the window. Unfortunately, this model does not take into account the dynamics of last factors development altogether. This task can be handled by the other model, numerical, implemented in Vulkan-M software. It is based on solving the gas dynamics equation system using large-particle method in Eulerian representation with added flame propagation conditions. Besides, Vulkan-M can visualize the physical process evolution, as well as record how its parameters and indicators develop. Research results. It was found that if the window size is comparable to regulatory values, such a strong influence of window position on pressure is due not only to the difference of out flowing gas properties (initial mixture and combustion products), but also dueto the factthatin the initial period of explosion development the flame front area is much larger for a further removed window than in case of a small distance between the window and ignition location. For a smaller window, the pressure increase rate in the initial period is high and almost identical for both explosion scenarios. Therefore, combustion time becomes decisive for the maximum pressure value. If the window is located far from the ignition, combustion time is shorter than in case of a smaller distance. As a result, maximum pressure in the second case is higher than in the first case. This explains the revealed phenomenon. Conclusion. The larger the window size, the stronger it affects the explosion pressure. This influence is determined not only by gas outflow, but it intensifies, sometimes significantly, due to the influence on flame front development. If the window size is decreased, its influence on flame front development is weakened and becomes negligible. In this case, the explosion pressure is affected by combustion time, besides window size.

Effect of citalopram on esophageal motility in healthy subjects-Implications for reflux episodes, dysphagia, and globus.

Drugs such as citalopram, "targeting" the serotonin pathway, can alter esophageal mechano-chemical sensitivity and gastrointestinal motility. The aim of this study was to clarify the effect of citalopram on esophageal motility and sphincter function, transient lower esophageal sphincter relaxations (TLESRs), and reflux events. Sixteen healthy volunteers (HV) receiving 20mg citalopram or placebo intravenously, in a randomized cross-over fashion, underwent two high-resolution impedance manometry studies involving liquid swallows and a high-fat, high-caloric meal. Manometric, reflux, and symptom-related parameters were studied. A lower distal contractile integral was recorded under citalopram, compared with placebo (P=0.026). Upper esophageal sphincter (UES) resting pressure was significantly higher after citalopram administration throughout the study (P<0.05, all periods). Similarly, the UES postswallow mean and maximum pressures were higher in the citalopram condition (P<0.0001, in both cases) and this was also the case for the 0.2s integrated relaxation pressure (P=0.04). Esophagogastric junction resting pressures in the citalopram visit were significantly higher during swallow protocol, preprandial period, and the first postprandial hour (P<0.05, in all cases). TLESRs and total reflux events were both reduced after citalopram infusion (P=0.01, in both cases). During treatment with citalopram, five participants complained about globus sensation (P=0.06). This citalopram-induced globus was associated with higher UES postswallow mean and maximum pressure values (P=0.01 and P=0.04, respectively). Administration of citalopram exerts a diversified response on esophageal motility and sphincter function, linked to clinically relevant phenomena: a reduction in postprandial TLESRs and the induction of drug-induced globus.