Pump Volume Research Articles

Automated pipette failure monitoring using image processing for point-of-care testing devices

BackgroundThe accuracy and precision of liquid handling can be altered by several causes including wearing or failure of parts, and human error. The last cause is crucial since point-of-care testing (POCT) devices can be used by non-experienced users or patients themselves. Therefore it is important to improve the method of informing the users of POCT device malfunctions due to damage of parts or human error.MethodsIn this paper, image-based failure monitoring of the automated pipetting was introduced for POCT devices. An inexpensive, high-performance camera for smartphones was employed in our previous work to resolve various malfunctions such as incorrect insertion of the tip, false positioning of the tip and pump, and improper operation of the pump. The image acquired from the camera was analyzed to detect the malfunctions. In this paper, the reagent volume in the tip was estimated from the image processing to verify the pump operation. First, the color component corresponding to the reagent intrinsic color was extracted to identify the reagent area in the tip before applying the binary image processing. The extracted reagent area was projected horizontally and the support length of the projection image was calculated. As the support length was related to the reagent volume, it was referred to the volume length. The relationship between the measured volume length and the previously measured solution mass was investigated. If we can predict the mass of the solution by the volume length, we will be able to detect the pump malfunction.ResultsThe cube of the volume length obtained by the proposed image processing method showed a very linear relationship with the reagent mass in the tip injected by the pumping operation (R2 = 0.996), indicating that the volume length could be utilized to estimate the reagent volume to monitor the accuracy and precision of the pumping operation.ConclusionsAn inexpensive smartphone camera was enough to detect various malfunctions of a POCT device with pumping operation. The proposed image processing could monitor the level of inaccuracy of pumping volume in limited range. The simple image processing such as a fixed threshold and projections was employed for the cost optimization and system robustness. However it delivered the promising results because the imaging condition was highly controllable in the devices.

Investigation of Parameters for Preparing Nanofiber Yarn via a Stepped Airflow-assisted Electrospinning

Electrospinning is a simple and cost-effective method to prepare fiber with nanometer scale. More importantly, 3D flexible nanofiber yarns that fabricated by electrospinning have shown excellent application prospects in smart textiles, wearable sensors, energy storage devices, tissue engineering, and so on. However, current methods for preparing electrospinning nanofiber yarns had some limitations, including low yarn yield and poor yarn structure. In this paper, a stepped airflow-assisted electrospinning method was designed to prepare continuously twisted nanofiber yarn through introducing stepped airflow into traditional electrospinning system. The stepped airflow could not only help to improve nanofiber yield, but also good for controlling the formed nanofibers to be deposited in a small area. In addition, the experimental methods of single factor variables were used to study the effects of stepped airflow pressure, applied voltage, spinning distance, solution flow rate, air pumping volume and friction roller speed on nanofiber yarn yield, nanofiber diameter, yarn twist and mechanical property. The results showed that prepared nanofiber yarns exhibited perfect morphologies and the yield of nanofiber yarn could reach to a maximum of 4.207 g/h. The breaking strength and elongation at break of the prepared yarn could reach to 23.52 MPa and 30.61 %, respectively.

Design and Characterization of a Soft Dielectric Elastomer Peristaltic Pump Driven by Electromechanical Load

Pumps are widely used in nature and engineering to transport fluids, particles, and mixtures. Compared to those in engineering, most natural pumps are soft, highly efficient, and reliable. In this paper, we design a soft dielectric elastomer peristaltic pump (DEPP) inspired by the human heart. The DEPP is composed of two pump modules and each module consists of four layers of dielectric elastomer membrane and three layers of carbon grease as electrodes. The two pump modules are driven by two complementary signals with different waveforms including square, sine, sawtooth, and triangular waves. We build a measuring system including pressure and flow rate sensors to characterize the DEPP's performance. The experimental results reveal that the square wave voltage provides the highest flow rate and pressure difference compared to the other three waveforms. The mechanical resonance of DEPP is observed and the optimal frequency with square wave voltage is about 1.5 Hz, which falls in the range of the human heart rate. The optimal frequency decreases with the increase of electromechanical loads. In the experiment, compared with the existing dielectric elastomer pump, we obtain the highest average flow rate and the highest instant flow rate as 2.5 L/min and 3.2 L/min, respectively. The maximum pump volume per cycle for the DEPP is 0.09 L. It takes about 1 s for the DEPP to reach a new equilibrium state when the working frequency of the voltage is switched from 1 to 1.5 Hz. It is hoped that this study will guide the development of new artificial hearts and other soft industrial pumps.

Exploring the Emergence of the Self-Q-Switching in Diode-Pumped Yb:KGW Monolithic Lasers

We perform through experiments to explore the key factors for the emergence of a self-Q-switching phenomenon in diode-pumped Yb:KGW lasers. In addition to the output transmission, it is found that the mode-to-pump size ratio is a critical factor leading to the self-Q-switching. The region of the cavity mode volume without overlapping the pump volume plays a role of modulation loss to result in self-Q-switching. With an output transmission of 4% and a mode-to-pump size ratio of approximately 1.2, simultaneous self-Q-switching and self-mode-locking with the repetition rate of 23.1 GHz were experimentally observed. At an incident pump power of 9.2 W, the maximum pulse energy was estimated to be 1.4 μJ at the repetition rate of 880 kHz with an average output of 1.27 W.

Dielectric Elastomer Fluid Pump of High Pressure and Large Volume Via Synergistic Snap-Through

Harnessing reversible snap-through of a dielectric elastomer (DE), which is a mechanism for large deformation provided by an electromechanical instability, for large-volume pumping has proven to be feasible. However, the output volume of snap-through pumping is drastically reduced by adverse pressure gradient, and large-volume pumping under high adverse pressure gradient by a DE pump has not been realized. In this paper, we propose a new mechanism of DE fluid pumping that can address this shortcoming by connecting DE pumps of different membrane stiffnesses serially in a pumping circuit and by harnessing synergistic interactions between neighboring pump units. We build a simple serial DE pump to verify the concept, which consists of two DE membranes. By adjusting the membrane stiffness appropriately, a synergistic effect is observed, where the snap-through of membrane 1 triggers the snap-through of membrane 2, ensuring that a large volume (over 70 ml/cycle) can be achieved over a wide range of large adverse pressure gradients. In comparison, the conventional single DE pump's pumping volume rapidly decreased beyond a low adverse pressure gradient of 0.196 kPa. At the pressure difference of 0.98 kPa, the serial DE pump's pumping volume is 4185.1% larger than that of the conventional DE pump. This pumping mechanism is customizable for various pressure ranges and enables a new approach to design DE-based soft pumping devices such as a DE total artificial heart, which requires large-volume pumping over a wide range of pressure difference.

Groundwater remediation optimization using Solving Constraint Integer Program (SCIP)

Simulation-optimization methods have increasingly been used to develop optimal solutions for a variety of groundwater remediation systems. The feasibility of these approaches is often dependent on their simplicity in application and software accessibility. Therefore, it is imperative to evaluate the applicability of a freely accessible and user friendly algorithm in the design of more robust groundwater remediation solutions. In this study, we present a coupled simulation-optimization model with solving constraint integer program (SCIP) algorithm in designing of groundwater remediation procedure of a polluted aquifer. The proposed method is illustrated by applying to a hypothetical groundwater problem. The primary objective of optimization in this work was to minimize the total pumping volume of water from a confined aquifer, subject to the state variable constraints such that the resulting decrease in hydraulic head and contaminant concentration in a set of control boreholes are within specified target levels. Borehole pumping rates were considered as decision variables of the optimization problem. The results of two cases demonstrate that the SCIP algorithm has the ability to design a groundwater remediation system of a polluted aquifer with a high degree of accuracy. Results of the SCIP were compared to firefly algorithm (FA) and indicated potential gains in efficiency to identify robust and reliable groundwater remediation system.

Corrugated diaphragm shape design study for hemocompatible pulsatile ventricular assist devices

We aim to maximize the pumping volume of a pulsatile ventricular assist device, where the diaphragm is covered with an endothelial cell layer. These cells are estimated to survive a cyclic strain up to fifteen percent. To increase the pumping volume under this strain constraint we use an approach based on corrugation of the diaphragm in its reference configuration. The paper explains the parametrization scheme for finding corrugation shapes, addresses modeling and evaluation schemes and reports on the results of a parameter study. The results show that corrugated diaphragm shapes are effective for increasing pumping volumes under a strain constraint.

The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development

In this work, the study results of an implantable pediatric rotary blood pump (PRBP) are presented. They show the results of the numerical simulation of fluid flow rates in the pump. The determination method of the backflows and stagnation regions is represented. The operating points corresponding to fluid flow rates of 1, 3, and 5 L/min for 75-80 mm Hg pressure head are investigated. The study results have shown that use of the pump in the 1 L/min operating point can potentially lead to the appearance of backflows and stagnation regions. In the case of using pumps in fluid flow rates ranging from 3 to 5 L/min, the number of stagnation regions decreases and the fluid flow rate changes marginally. Using the pump in this flow rate range is considered judicious. The study shows an increase in shear stress with an increase in fluid flow rates, while there is no increase in shear stress above the critical condition of 150 Pa (which does not allow us to reliably speak about the increased risk of blood cell damage). The aim of this work was to design, prototype, and study interaction of the Sputnik PRBP with the cardiovascular system. A three-dimensional model of Sputnik PRBP was designed with the following geometrical specifications: flow unit length of 51.5 mm, flow unit diameter of 10 mm, and spacing between the rotor and housing of 0.1 mm. Computational fluid dynamics studies were used to calculate head pressure-flow rate (H-Q) curves at rotor speeds ranging from 10000 to 14000 rpm (R2 = 0.866 between numerical simulation and experiment) and comparing flow patterns at various points of the flow rate operating range (1, 3, and 5 L/min) for operating pressures ranging from 75 to 80 mm Hg. It is noted that when fluid flow rate changes from 1 L/min to 3 L/min, significant changes are observed in the distribution of zero flow zones. At the inlet and outlet of the pump, when going to the operating point of 3 L/min, zones of stagnation become minuscule. The shear stress distribution was calculated along the pump volume. The volume in which shear stress exceed 150 Pa is less than 0.38% of the total pump volume at flow rates of 1, 3, and 5 L/min. In this study, a mock circulatory system (MCS) allowing simulation of physiological cardiovascular characteristics was used to investigate the interaction of the Sputnik PRBP with the cardiovascular system. MCS allows reproducing the Frank-Starling autoregulation mechanism of the heart. PRBP behavior was tested in the speed range of 6000 to 15000 rpm. Decreased contractility can be expressed in a stroke volume decrease approximately from 18 to 4 mL and ventricle systolic pressure decrease approximately from 92 to 20 mm Hg. The left ventricle becomes fully supported at a pump speed of 10000 rpm. At a pump speed of 14000 rpm, the left ventricle goes into a suction state in which fluid almost does not accumulate in the ventricle and only passes through it to the pump. The proposed PRBP showed potential for improved clinical outcomes in pediatric patients with a body surface areagreater than 0.6 m2 and weight greater than 12 kg.

Ultra-low-threshold InGaN/GaN quantum dot micro-ring lasers

In this work, we demonstrate ultra-low-threshold, optically pumped, room-temperature lasing in GaN microdisk and micro-ring cavities containing InGaN quantum dots and fragmented quantum wells, with the lowest measured threshold at a record low of 6.2 μJ/cm2. When pump volume decreases, we observe a systematic decrease in the lasing threshold of micro-rings. The photon loss rate, γ, increases with increasing inner ring diameter, leading to a systematic decrease in the post-threshold slope efficiency, while the quality factor of the lasing mode remains largely unchanged. A careful analysis using finite-difference time-domain simulations attributes the increased γ to the loss of photons from lower-quality higher-order modes during amplified spontaneous emission.

Alkanes based two-stage expansion with interheating Organic Rankine cycle for multi-waste heat recovery of truck diesel engine

The environment issue combined with the rising of crude oil price has attracted more attention in waste heat recovery of diesel engine. The Organic Rankine cycle (ORC) offers a good solution to utilize multi-grade waste heats of diesel engine. Conventional multi-source ORC systems are too complex for vehicle application. This paper proposed a two-stage expansion with interheating organic Rankine cycle (ORC) system using alkanes as working fluids, in order to recover multi-waste heats (exhaust gas, EGR gas and engine coolant) with simple system configuration and solve the problem of overlarge expansion ratio of alkanes. Thermodynamic models based on first and second thermodynamic law are established. A correlation was proposed to estimate the optimum intermediate pressure to achieve maximum net power output. System performance comparison among alkanes shows that cyclic alkanes are superior to linear alkanes regarding net power output, thermal efficiency and exergy losses although they are weaker in recovering heat from engine coolant. Compared with the conventional preheating-regenerative ORC system, the proposed system can recover waste heat of exhaust gas (100%) and EGR gas (71.8%) more efficiently and generate 6.7% more output power, and it is more compact in terms of heat exchangers size, pump volumes and turbine structure.

Entrainment of Juvenile and Adult American Shad at a Pumped Storage Facility

AbstractThe American Shad Alosa sapidissima has been targeted for restoration to the upper Susquehanna River, and entrainment losses at hydroelectric facilities on the river, including the Muddy Run Pumped Storage Facility, are of concern for the potential growth of the American Shad population. Based on the integration of pumping volume, time of entrainment, and literature‐reported diel emigration of juvenile American Shad, the entrainment rate (N = 145; 53 exposed to pumping) was estimated at 3.5%. The entrainment rate for adults (N = 507) was estimated at 0.3–3.9%. Using multistate mark–recapture models, the estimated entrainment probabilities (Ψ) of radio‐tagged juveniles were higher during periods of extended pumping (>1 h; Ψ = 0.093; 95% confidence interval [CI] = 0.054–0.156) than at periods of no pumping or short‐duration pumping (<1 h; Ψ < 0.0001; 95% CI = 0.0–0.001); the high extended pumping occurred between 2300 and 0600 hours. Entrainment probabilities for adults were low (Ψ < 0.02); the highest probability occurred for fish detected downstream of the intake during the peak portion of the run (Ψ = 0.015; 95% CI = 0.004–0.047). Entrainment probability for most adult fish did not differ from zero. The low values of Ψ for both life stages were attributed to (1) the deep location of the intake (intake ceiling >11.7 m below the water surface), (2) the surface orientation of American Shad (upper 3.1 m), (3) the low overlap between high‐volume pumping and peak emigration/migration times, (4) the pumping volume relative to prevailing river flows, and (5) the prolonged, robust swimming speed of American Shad, particularly that of adults (>2.2 m/s), which exceeded the intake velocity (0.2–0.9 m/s). Entrainment of juveniles increased with co‐occurrence of low incoming river flows, high pumping volume, and peak emigration times. Quantification of migratory species’ entrainment at pumped storage facilities requires integration of diel migration/emigration times with the frequency, timing, and duration of pumping volume.

Autonomous Optofluidic Chemical Analyzers for Marine Applications: Insights from the Submersible Autonomous Moored Instruments (SAMI) for pH and pCO2

The commercial availability of inexpensive fiber optics and small volume pumps in the early 1990’s provided the components necessary for the successful development of low power, low reagent consumption, autonomous optofluidic analyzers for marine applications. It was evident that to achieve calibration-free performance, reagent-based sensors would require frequent renewal of the reagent by pumping the reagent from an impermeable, inert reservoir to the sensing interface. Pumping also enabled measurement of a spectral blank further enhancing accuracy and stability. The first instrument that was developed based on this strategy, the Submersible Autonomous Moored Instrument for CO2 (SAMI-CO2), uses a pH indicator for measurement of the partial pressure of CO2 (pCO2). Because the pH indicator gives an optical response, the instrument requires an optofluidic design where the indicator is pumped into a gas permeable membrane and then to an optical cell for analysis. The pH indicator is periodically flushed from the optical cell by using a valve to switch from the pH indicator to a blank solution. Because of the small volume and low power light source, over 8,500 measurements can be obtained with a ~500 mL reagent bag and 8 alkaline D-cell battery pack. The primary drawback is that the design is more complex compared to the single-ended electrode or optode that is envisioned as the ideal sensor. The SAMI technology has subsequently been used for the successful development of autonomous pH and total alkalinity analyzers. In this manuscript, we will discuss the pros and cons of the SAMI pCO2 and pH optofluidic technology and highlight some past data sets and applications for studying the carbon cycle in aquatic ecosystems.

Miniaturized Diaphragm Vacuum Pump by Multi-Material Additive Manufacturing

This paper reports the first demonstration of a multi-material, fully additively manufactured, miniature diaphragm pump for creation and maintenance of low vacuum from atmospheric conditions. Using polyjet 3-D printing technology with $42~\mu \text{m}$ XY pixelation and $16~\mu \text{m}$ or $25~\mu \text{m}$ tall voxels, a single-stage vacuum pump design with active valves that has a total pumping volume of 1 cm3 with 5% dead volume was implemented. Optimization of the devices resulted in manufacturing different constitutive parts of the pump in flexible materials of different stiffness. Finite element simulations of the pump design estimate at 0.20 MPa the maximum stress on the piston diaphragm root at full actuation, and at 106 Hz the natural frequency of the compression chamber. While operating at 1.82 Hz, the devices consistently pumped down from atmospheric pressure to 110 Torr in under 4 s, which is the smallest and fastest base pressure reported in the literature for a microfabricated diaphragm vacuum pump. In addition, the pumps can deliver mass flow rates as high as 200 sccm at 535 Torr, which is much higher than any of the reported flow rates from a diaphragm vacuum pump manufactured with standard microfabrication. The outgassing rate of the TangoBlack Plus® photopolymer used to print the pumps was measured and is on par with vacuum compatible elastomers. Compression chamber diaphragms exhibited lifetimes approaching 1 millioncycles, while the valves membranes have not leaked after over 2 million cycles. [2017-0100]

A robust dual-membrane dielectric elastomer actuator for large volume fluid pumping via snap-through

A pressurized dielectric elastomer (DE) diaphragm under electrical actuation can experience snap-through large deformation due to electromechanical instability, which was shown to be a promising mechanism for large volume fluid pumping. However, snap-through actuation in a DE fluid pump will not occur when the inlet pressure to the pump is small and cannot be robustly utilized for different applications. To solve this problem, in this study, we proposed a dual-membrane DE pump design featuring an active DE membrane interacting with a passive elastic membrane. This design enabled snap-through of the DE membrane over a wide range of inlet pressures, making it feasible for large volume fluid pumping even at low pressures. Merits of this dual-membrane DE actuator design were experimentally verified; for example, the pumping volume of the dual-membrane DE pump could be as large as 3944% of the pumping volume of the conventional single-membrane DE pump. We further proposed an analytical framework to describe the mechanism of the dual-membrane DE fluid pump, involving the superimposition of the pressure-volume curves of the active and passive membranes. The theoretically predicted equilibrium states agreed well with experimental observations. Findings in this study will broaden the applications of the DE actuator in scenarios where a large pumping volume is needed over a wide range of pressures.

Agua de lluvia para consumo humano y uso doméstico en San Miguel Tulancingo, Oaxaca

El estudio se realizó en el municipio de San Miguel Tulancingo, Oaxaca donde los habitantes usan para sus necesidades de agua de consumo humano y uso doméstico 30 L habitante-1 día-1. El objetivo es diseñar un Sistema de Captación del Agua de Lluvia para dotar con agua de calidad, en cantidad y de manera continua a los habitantes del municipio. El diseño del sistema consistió en: la localización del sistema a nivel macro y micro, calcular la demanda de agua, la precipitación pluvial neta, el área efectiva de captación, los diámetros de las tuberías, el volumen del sedimentador, los almacenamientos y la bomba solar, para finalmente diseñar el tren de tratamiento para potabilizar y purificar el agua de lluvia.

Does Pumping Volume Affect the Concentration of Micropollutants in Groundwater Samples?

AbstractInformation on concentrations of micropollutants (such as pharmaceuticals, pesticides, and industrial chemicals) in most highly dynamic riverbank filtration (RBF) systems is lacking, in contrast to data on standard chemical parameters. Sampling protocols have thus far been based on the stabilization of standard chemical parameters in relatively pristine environments. To determine whether groundwater samples for micropollutant analysis can be taken at a similar pumping volume as samples for testing standard chemical parameters in both environments, three groundwater monitoring wells in an RBF system were sampled at two points in time (after pumping of 3 well volumes and after pumping of 15 well volumes). Micropollutant concentrations were not significantly different between the two sampling points; therefore, appropriate samples can be drawn after pumping 3 well volumes. For a specific microbiological parameter (leucin incorporation), a statistically significant difference was found.

ADAM, a hands-on patient simulator for teaching principles of drug disposition and compartmental pharmacokinetics.

AimsTo design, construct and validate a pharmacokinetics simulator that offers students hands‐on opportunities to participate in the design, administration and analysis of oral and intravenous dosing regimens.MethodsThe Alberta Drug Administration Modeller (ADAM) is a mechanical patient in which peristaltic circulation of water through a network of silicone tubing and glass bottles creates a representation of the outcomes of drug absorption, distribution, metabolism and elimination. Changing peristaltic pump rates and volumes in bottles allows values for pharmacokinetic constants to be varied, thereby simulating differences in drug properties and in patient physiologies and pathologies. Following administration of methylene blue dye by oral or intravenous routes, plasma and/or urine samples are collected and drug concentrations are determined spectrophotometrically. The effectiveness of the simulator in enhancing student competence and confidence was assessed in two undergraduate laboratory classes.ResultsThe simulator effectively models one‐ and two‐compartment drug behaviour in a mathematically‐robust and realistic manner. Data allow calculation of numerous pharmacokinetic constants, by traditional graphing methods or with curve‐fitting software. Students' competence in solving pharmacokinetic problems involving calculations and graphing improved significantly, while an increase in confidence and understanding was reported.ConclusionsThe ADAM is relatively inexpensive and straightforward to construct, and offers a realistic, hands‐on pharmacokinetics learning opportunity for students that effectively complements didactic lectures.

양구해안분지에서 기존 농업용수 이용량 산정식에 따른 양수량과 실측 양수량 비교

Efficient groundwater management requires accurate information about the water volume used. The pumped volume of groundwater can be indirectly estimated using empirical formulae based on electric power consumption. The purpose of this study is to test the accuracy of this indirect method. The Haean basin in Gangwon is located in a rural area, where majority of the groundwater extracted is used for irrigation. The pumped volume of groundwater indirectly estimated from electricity usage using these empirical formulae was compared with the actual pumped volume determined by conducting experiments on April 29 and May 19, 2017. The field survey collected data on electricity usage, pumped volume, and groundwater levels. Based on this measured data, correlations were calculated between electricity usage and pumping volume, as well as groundwater level and pumping rate. The results show that electricity usage and pumped volume measured for both wells (YHE1 and YHE2) are highly correlated (r=0.99, p<0.001). However, for YHE1, notably, the correlation between the groundwater level and pumping rate was not significant, and only some correlations were identified for these variables for the YHE2 test well. The average error with respect to the estimation of the actual pumped volume from the existing formula (1) and formulae (2) and (3) are +399% and -88%, respectively. To reduce these errors, these formulae need to consider other factors affecting the pumped volume.

The mechanism for large-volume fluid pumping via reversible snap-through of dielectric elastomer

Giant deformation of dielectric elastomers (DEs) via electromechanical instability (or the “snap-through” phenomenon) is a promising mechanism for large-volume fluid pumping. Snap-through of a DE membrane coupled with compressible air has been previously investigated. However, the physics behind reversible snap-through of a DE diaphragm coupled with incompressible fluid for the purpose of fluid pumping has not been well investigated, and the conditions required for reversible snap-through in a hydraulic system are unknown. In this study, we have proposed a concept for large-volume fluid pumping by harnessing reversible snap-through of the dielectric elastomer. The occurrence of snap-through was theoretically modeled and experimentally verified. Both the theoretical and experimental pressure-volume curves of the DE membrane under different actuation voltages were used to design the work loop of the pump, and the theoretical work loop agreed with the experimental work loop. Furthermore, the feasibility of reversible snap-through was experimentally verified, and specific conditions were found necessary for this to occur, such as a minimum actuation voltage, an optimal range of hydraulic pressure exerted on the DE membrane and a suitable actuation frequency. Under optimal working conditions, we demonstrated a pumping volume of up to 110 ml per cycle, which was significantly larger than that without snap-through. Furthermore, we have achieved fluid pumping from a region of low pressure to another region of high pressure. Findings of this study would be useful for real world applications such as the blood pump.

Computational study on the effect of slug dynamics on the operation of a polyolefin 8-leg loop reactor of industrial scale

The causes and ad-hoc remedies associated with the formation of slugs that result in pump power fluctuation inside slurry loop reactors have been discussed in several patent literature, but studied in few research publications. The circulation of large polymer slugs inside loop reactors can induce violent fluctuations of pump power that can lead to automatic shutdown of the entire production process. In our previous work, we have developed a computational fluid dynamic (CFD) model using the Eulerian – Eulerian two fluid method to study the solid segregation and solid dispersion mechanisms inside an 8-leg loop reactor of industrial scale. Herein we adopt this model to study the response of such loop reactor to the slug circulation. The modeling results reveal that the profiles of reactor outputs, i.e., solid volume fractions, velocity magnitudes and pump pressure output, demonstrate random fluctuations with small amplitudes when the reactor is in normal operations. However, these profiles show drastic fluctuations in a periodic manner once a large slug is circulating around the loop reactor. The solid dispersion mechanism governed by the secondary flow inside vertical legs cannot dissipate the slug effectively as the dispersion occurs primarily on the radial direction. Therefore, a mitigation method that offers mixing in the transverse direction is necessary to assure safe and continuous production process.