Stage Of Discharge Research Articles

Visualization of Dissolution‐Precipitation Processes in Lithium–Sulfur Batteries

AbstractIn this work, light is shed on the dissolution and precipitation processes S8 and Li2S, and their role in the utilization of active material in LiS batteries. Combining operando X‐ray Tomographic Microscopy and optical image analysis, in real‐time; sulfur conversion/dissolution in the cathode, the diffusion of polysulfides in the bulk electrolyte, and the redeposition of the product of the electrochemical reaction, Li2S, on the cathode are followed. Using a custom‐designed capillary cell, positioning the entire cathode volume within the field of view, the conversion of elemental sulfur to soluble polysulfides during discharge is quantitatively followed. The results show the full utilization of elemental sulfur in the cathode in the initial stage of discharge, with all solid sulfur converted to soluble polysulfide species. Optical image analysis shows a rapid diffusion of polysulfides as they migrate from the cathode to the bulk electrolyte at the start of discharge and back to the cathode in the later stages of discharge, with the formation and precipitation of Li2S. The results point to the redeposition of Li2S on all available surfaces in the cathode forming a continuous insulating layer, leaving polysulfide species remaining in the electrolyte, and this is the process limiting the cell's specific capacity.

Hyperglycemia and blood glucose deterioration are risk factors for severe COVID-19 with diabetes: A two-center cohort study.

We aimed to assess whether blood glucose control can be used as predictors for the severity of 2019 coronavirus disease (COVID‐19) and to improve the management of diabetic patients with COVID‐19. A two‐center cohort with a total of 241 confirmed cases of COVID‐19 with definite outcomes was studied. After the diagnosis of COVID‐19, the clinical data and laboratory results were collected, the fasting blood glucose levels were followed up at initial, middle stage of admission and discharge, the severity of the COVID‐19 was assessed at any time from admission to discharge. Hyperglycemia patients with COVID‐19 were divided into three groups: good blood glucose control, fair blood glucose control, and blood glucose deterioration. The relationship of blood glucose levels, blood glucose control status, and severe COVID‐19 were analyzed by univariate and multivariable regression analysis. In our cohort, 21.16% were severe cases and 78.84% were nonsevere cases. Admission hyperglycemia (adjusted odds ratio [aOR], 1.938; 95% confidence interval [95% CI], 1.387–2.707), mid‐term hyperglycemia (aOR, 1.758; 95% CI, 1.325–2.332), and blood glucose deterioration (aOR, 22.783; 95% CI, 2.661–195.071) were identified as the risk factors of severe COVID‐19. Receiver operating characteristic (ROC) curve analysis, reaching an area under ROC curve of 0.806, and a sensitivity and specificity of 80.40% and 68.40%, respectively, revealed that hyperglycemia on admission and blood glucose deterioration of diabetic patients are potential predictive factors for severe COVID‐19. Our results indicated that admission hyperglycemia and blood glucose deterioration were positively correlated with the risk factor for severe COVID‐19, and deterioration of blood glucose may be more likely to the occurrence of severe illness in COVID‐19.

Temperature-dependent ion chemistry in nanosecond discharge plasma-assisted CH4 oxidation

Ion chemistry with temperature evolution in weakly ionized plasma is important in plasma-assisted combustion and plasma-assisted catalysis, fuel reforming, and material synthesis due to its contribution to plasma generation and state transition. In this study, the kinetic roles of ionic reactions in nanosecond discharge (NSD) plasma-assisted temperature-dependent decomposition and oxidation of methane are investigated by integrated studies of experimental measurements and mathematical simulations. A detailed plasma chemistry mechanism governing the decomposition and oxidation processes in a He/CH4/O2 combustible mixture is proposed and studied by including a set of electron impact reactions, reactions involving excited species, and ionic reactions. A zero-dimensional model incorporating the plasma kinetics solver ZDPlasKin and the combustion chemical kinetics solver CHEMKIN is used to calculate the time and temperature evolution of the ion density. Uncertainty analysis of ionic reactions on key species generation is conducted by using different referenced data, and insignificant sensitivity is found. The numerical model is consistent with experimental data for methane consumption and generation of major species including CO, CO2, and H2. By modeling the temporal evolution of key ions, it is observed that O2 + presents the largest concentration in the discharge stage, followed by CH4 +, CH3 +, and CH2 +, which is in accordance with the traditional ion chemistry in hydrocarbon flames and agrees well with molecular-beam mass spectrometer investigations. The path flux shows that the concentrations of key species, including electrons, O, OH, H, O(1D), O2(a1Δg), O2 +, CH3 +, and CH4 +, change within 1–2 orders of magnitude and that the transition from a homogeneous state to a contracted/constricted state does not occur. The path flux and sensitivity analysis reveal the significant roles of cations in the stimulation of active radical generation, including CH, O, OH, and O(1D), thus accelerating methane oxidation. This work provides a deep insight into the ion chemistry of temperature-dependent plasma-assisted CH4 oxidation.

Positive column dynamics of a low-current atmospheric pressure discharge in flowing argon

We present the results of studies of a cold-plasma atmospheric pressure discharge in argon flow, in both DC and pulse-periodic modes. The burning voltage and the discharge current were 200 V and 15 mA in continuous mode; in pulse-periodic mode the voltage was 220 V and the current 15 mA for a pulse repetition rate of 100 kHz. Special attention was given to the positive column dynamics during the discharge stages of initiation, burning, and extinction. The main method of investigation employed optical diagnostics of the plasma in the visible range with high time resolution. The positive discharge column is shown to be a constricted current channel in the form of an elongated loop. In continuous mode, the length of the positive column, from anode attachment to inflection point outside the discharge system, is several millimeters. In pulsed mode, the positive column is an unsteady plasma formation, the length of which increases at about 4 m s−1, and reaches the same dimension over a time of order 1 ms. We find that the positive column plasma includes hydroxyl molecules OH, nitrogen N2, and atomic oxygen O I, along with atoms of the working gas argon. Observation of the time evolution of the optical emission from the plasma-forming gas shows that the plasma glow of the positive column is mainly determined by argon Ar I radiation, with maximum intensity at the trailing edge of the current pulse.

Discharge Characteristic of Micro-Arc Oxidation on Aluminum Alloy under the Changing Electrolyte Temperature

The electrolyte temperature has a great influence on the performance of the coating prepared by micro-arc oxidation (MAO). The behavior of MAO discharge in the changing electrolyte temperature has been investigated. Compared to constant electrolyte temperature in conventional MAO process, the process has different discharge characteristics under the changing electrolyte temperature. The amplitude of pulse voltage was detected to study the change of discharge characteristic under the constant-current control of MAO power supply. Three successive discharge stages were differentiated by the variable the pulse voltage versus process time. Since there were significant changes in the sound, the sound signals were acquired and the audio analysis was used to describe the changing of the MAO discharge at different stages. Optical emission spectroscopy (OES) was employed in situ to unveil how the micro-discharge changed with the temperature increasing. Scanning electron microscopy (SEM) was used to characterize the morphology of the coatings on 6N01 aluminum alloy prepared by normal process with the constant-temperature control of the MAO electrolyte and by the process under the changing electrolyte temperature. A mode of film growth and micro-discharge was given to describe the effects of the changing electrolyte temperature in the whole MAO process.

Comparative analysis on emission characteristics of normal temperature cold start of gasoline vehicles

According to the requirements of Normal Temperature Cold Start for the current China six automobile, choose four different light-duty gasoline vehicles, use Beijing six gasoline to carried out type I emission test. Assess WLTC emissions of each interval under the condition of different emission difference, and the causes of pollutant formation in different stages were analyzed. The results show that the WLTC circulation under the cold start phase is still the most pollutants discharge stage, specific performance in cold start phase before the 50s, the main reason is that the exhaust temperature is too low and the catalyst does not light up; Secondly, more pollutants will be produced in the extra-high speed stage, in this stage, open-loop control is used.

Electrochemical and Corrosive Behavior of Iron in Acidic Chloride Media in the Presence of Pyrimidine

The effect of pyrimidine concentration (0.0005…0.01 М) on the kinetics of the reaction of hydrogen evolution on iron in conventionally anhydrous ethylene glycol solutions with the electrolyte composition x M HCl + (1 – x) M LiCl (where x = 0.99; 0.5; 0.1; 0.05, Mmol/l). A quantitative assessment of the concentration of pyrimidine ions and the molecular form of pyrimidine depending on the acidity of the medium is given. As a result of electrochemical measurements, it was shown that the introduction of various concentrations of pyrimidine into conventionally anhydrous ethylene glycol solutions (with the ionic strength of the solution equal to one) changes the nature of the limiting stage. In the background conditionally anhydrous ethylene glycol solutions, the limiting stage is the discharge reaction, the kinetic parameters of which are in satisfactory agreement with Folmer’s theory. In the presence of pyrimidine in solutions in the concentration range under consideration, the delayed discharge stage changes to the delayed chemical recombination stage. The observed experimental results are primarily due to the acid-base interactions of pyridine and solvent molecules, which are primarily due to the structural features of the molecule of this additive and the ratio of the number of particles of the protonated form of pyrimidine to the number of particles of the molecular form in conventionally anhydrous ethylene glycol solutions.

Early Mental Health and Quality of Life in Discharged Patients With COVID-19.

Aim: This study aimed to analyze the early mental health (MH) and quality of life (QoL) of discharged patients with coronavirus disease 2019 (COVID-19), which can provide a scientific basis for the further development of intervention programs.Methods: In total, 108 subjects participated in this study, including an experimental group (90 patients diagnosed with COVID-19 from March to April 2020 and hospitalized in Wuhan China Resources & WISCO General Hospital, Wuhan, China, 83.3%) and a control group (18 healthy participants, 16.7%). Their MH and QoL were measured through the 12-item Short Form Health Survey version 2 (SF-12v2), the Self-rating anxiety scale (SAS), the Self-rating depression scale (SDS), and the International Physical Activity Questionnaire (IPAQ). The results of questionnaires were compared between these two groups.Results: (1) Comparison of anxiety status: among 90 discharged patients with COVID-19, 30 patients (33.3%) had a state of anxiety. Compared with healthy participants and the general population, patients with COVID-19 in the early stages of discharge had a higher incidence of anxiety and more severe anxiety symptoms (P < 0.05). (2) Comparison of depression status: among 90 discharged patients with COVID-19, 29 patients (32.2%) had a state of depression. Compared with healthy participants and the general population, patients with COVID-19 in the early stages of discharge had a higher incidence of depression and more severe depression symptoms (P < 0.05). (3) Comparison of QoL: 78 patients (86.7%) presented a decrease in physical health-related quality of life (HRQoL) and 73 patients (81.1%) presented a decrease in psychology-related QoL. The SF-12v2 physical component summary (PCS) and the SF-12v2 mental component summary (MCS) of patients were significantly lower than those of healthy people, especially in physical function (PF), vitality (VT), social function (SF), and mental health (MH) (all P < 0.05). (4) Gender differences in mental health and the QoL among patients with COVID-19: women had more severe anxiety/depression symptoms than men (P < 0.05). The scores of women in all dimensions of SF-12V2 were lower than those of men, and there were statistically significant differences between the two groups in PCS, PF, general health (GH), VT, and role-emotional (RE) (P < 0.05).Conclusion: During the early phase after being discharged, patients with COVID-19 might experience negative emotions, such as anxiety or depression, and also problems with reduced QoL, especially among female patients. Therefore, an intervention plan should focus on strengthening psychological condition and improving physical function, and gender-specific rehabilitation programmes should be adapted to improve psychological status and QoL.

Experimental study on thermal runaway characteristic parameters of parallel battery modules

This work introduces a method for measuring the main physical quantities, such as short-circuit current and capacity loss, in the thermal runaway process of the parallel battery module and presents detailed analysis and discussion on a 25 Ah commercial prismatic lithium-ion ferrous phosphate (LFP) battery. By establishing a basic circuit model of the thermal runaway process of the parallel battery module, experiments were conducted to observe the thermal runaway process of the parallel battery module. The parameters related to the electrothermal effect in the thermal runaway process were obtained by either direct measurement or calculation. The results showed that the short-circuit resistance of the cell, which was triggered to thermal runaway changed dramatically. The minimum resistance was about 0.5 mΩ, and the peak current of discharge was more than 1100 A. During the stable discharge process of the other parallel cells to the thermal runaway cell, the short-circuit resistance was about 10 mΩ. In the stable discharge stage, the electric heating power was about 600 to 900 W. However, the power of thermal runaway reaction from the cell itself was still more than 30 times the heating power of the electrothermal effect, exceeding 21 kW. The accuracy of the measurement method and analysis method was also verified by comparing the same parametric data obtained using different methods. The results showed that the method is feasible for studies on the mechanism and simulation of thermal runaway of parallel battery modules.

Reaction chain used to describe the process and mechanism of helium breakdown under high pressure

In this study, we establish a two-dimensional axisymmetric fluid model and verify its efficacy via experiments. We analyze the reaction rates to introduce a concept that we have termed “reaction chain” to describe the process and mechanism of helium discharge at high pressure. We observe that the entire process of discharge can be perfectly described by the reaction chains, which indicates that the breakdown process of helium involves a series of chain reactions, just like the nuclear fission. The results revealed that ground-state ionization reaction predominates the early discharge stage, whereas with the quick accumulation of He2*, penning ionization reaction will eventually play a dominant role. Our study confirms that metastable atoms play an important role in helium discharge. We demonstrated that He* is converted into He2* as an intermediate and that the number density of He2* eventually influences the breakdown of helium.

Crystal structure variation of LiMn1.5Ni0.5O4 high-voltage spinel cathode during low-voltage redox reaction

Using operando X-ray diffraction, crystal structure variation of high-purity spinel cathode LiMn1.5Ni0.5O4 at voltages of 2.1–3.5 V vs. Li anode was studied. Results showed that the low-voltage Li+ extraction–insertion reaction proceeded in a two-phase reaction with a long voltage plateau around 2.8 V, where cubic and tetragonal spinel phases coexist. Their lattice volume difference was approximately 4.9%. That difference, which is small compared to that of ordinary LiMn2O4 spinel compound, implies that the Jahn-Teller distortion can slightly influence Li+ extraction-insertion reaction reversibility. Therefore, the redox reaction occurred over the wide voltage range of 2.5–4.9 V, at which simultaneous calorimetric measurements were conducted. Capacity fading during redox cycling was sufficiently small, but not negligible. A large exothermic reaction was detected at both charge and discharge stages, although only a small exothermic reaction was observed in both 2.8 V and 4.7 V plateau regions. The irreversibility can be attributed to the reaction at the transition region between high-voltage redox and low-voltage redox.

Effect of inhomogeneous magnetic field on blue core in Ar helicon plasma

The effect of the inhomogeneous magnetic field on blue core phenomena in helicon plasma is investigated in this work. The permanent magnets (PMs) are used to provide the magnetic field required for generation of helicon plasma, and three different types of the inhomogeneous magnetic field are constructed by changing the permanent magnets positions, which are PM-top/bottom, PM-top, and PM-bottom, respectively. The maximum magnetic field strengths in these three types of inhomogeneous magnetic fields are at both ends (case A), at the upper end (case B), and at the lower end (case C) of the discharge tube, respectively. Nikon camera, an intensified charge coupled device, optical emission spectrometer (OES), and Langmuir probe are used to diagnose the blue core phenomenon in helicon plasma. The electronic excitation temperature is calculated based on optical emission lines captured by OES. Helicon wave discharge is affirmed by mode transition with three discharge stages corresponding to E-, H- and W-modes, respectively. The blue core could occur in the maximum magnetic field strengths located at both ends at around 200 W, at the upper end at around 300 W, and at the lower end at around 400 W. The formation of blue core in the present work can be attributed to the non-uniformity of the inhomogeneous magnetic field. Meanwhile, the radial distribution of plasma density and electron temperature in blue core is different. The plasma density still maintains the on-axis peak, and electron temperature transforms from on-axis peak to off-axis peak due to the skin effect.

Thermal management evaluation of Li-ion battery employing multiple phase change materials integrated thin heat sinks for hybrid electric vehicles

The optimal performance of a Li-ion battery is directly impacted by temperature. In order to control the temperature rise and provide even temperature distributions in the battery pack, a thermal management scheme comprises thin heat sinks with multiple phase change materials (PCMs) and air channels is investigated in this paper. The cooling performance and temperature homogenization of the battery thermal management (BTM) system are carefully studied under various configurations of PCMs. The results show that increasing the air inlet velocity has less effect in suppressing the temperature rise at early discharge stage, but ameliorates as the discharge prolonged to 3600 s. The standard deviation of the temperature (STDV) and maximum temperature of the batteries can be decreased by arranging PCMs with a lower melting temperature at the midsection and a higher melting temperature at the air outlet region of the heat sinks. In addition, for volume fraction of PCMs, Case IV, having a PCM with a higher melting point adjacent to the air outlet region and occupying one-half the height of the heat sink, illustrates a lower temperature rise and decreases the maximum temperature in the battery module by 1.024 K, 2.186 K, and 2.553 K, compared to Case I, II, and III, respectively.

Effect of laser on double-arc physical characteristics in pulsed laser-induced double-TIG welding

In order to improve the melting efficiency of double-TIG arc, based on the synchronous induction of pulsed laser to double-arc, the coupling-enhanced discharge phenomenon between double-arcs is studied in this paper. The melting efficiency of pulsed laser-induced double-arc is quantitatively analyzed. The physical characteristics of coupling double-arc are studied based on high-speed camera and spectral diagnosis technology. The physical model is established to discuss the particle migration during the coupling discharge, characterizing the movement state of electrons. The results show that Dla (horizontal distance between the tungsten electrode tip and laser beam axis) has a significant effect on the melting efficiency of the heat source. With the increase of Dla, there are three interaction relationships between the double-arc plasma and keyhole plasma: mutual interference, coupling-enhanced discharge, and no interaction. A suitable Dla can realize the synchronous induction of laser to double-arc plasma, forming a coupling double-arc; the heat source has a higher melting efficiency. The migration of particles in double-arc can be divided into four stages: double-arc free discharge stage, laser-induced initial stage, laser-induced contraction stage, and laser-induced stable stage. Under the induction of laser, the double-arc forms a common compressed conductive channel. The energy density of coupling double-arc reaches 9.3 times that of traditional double-arc, and the total electron kinetic energy increases by 38% compared with traditional double-arc.

Increasing the energy of the initiating spark discharge in order to reduce and stabilize the delay time in a compact vacuum breaker

The similarity of the switching mechanisms of compact vacuum spark breakers and spark breakers with laser ignition is established at a comparable level of energy flux density in the ignition node–ionization of the residual gas by a stream of short-wave radiation and fast electrons from the cathode spot plasma or laser plasma. This mechanism allows you to effectively reduce the delay in triggering the spark gap by increasing the ignition energy. An experimental study of the advantages of using an ignition circuit with increased energy for controlling small-sized vacuum spark breakers is carried out. There is a steady decrease in the delay time of the spark gap and an increase in the level&#x0D; of delay stability. From the point of view of minimization and stability of the delay time of the spark gap, the energy investment in the formation of the initiating plasma occurs most effectively at the spark stage of the auxiliary discharge along the surface of the dielectric in the ignition node.

New Insight into the Working Mechanism of Lithium-Sulfur Batteries under a Wide Temperature Range.

Sweet potato-derived carbon with a unique solid core/porous layer core/shell structure is used as a conductive substrate for gradually immobilizing sulfur to construct a cathode for Li-S batteries. The first discharge specific capacity of the Li-S batteries with the C-10K@2S composite cathode at 0.1C is around 1645 mAh g-1, which is very close to the theoretical specific capacity of active sulfur. Especially, after 175 cycles at 0.5C, the maintained specific discharge capacities of the C-10K@2S cathode at -20, 0, 25, and 40 °C are about 184.9, 687.2, 795.5, and 758.3 mAh g-1, respectively, and the cathode is superior to most of the classical carbon form matrices. Working mechanisms of the cathodes under different temperatures are confirmed based on X-ray photoelectron spectroscopy (XPS) and in situ X-ray diffraction (XRD) characterizations. Distinctively, during the discharge stage, the widely proposed two-step cathodic reactions occur simultaneously rather than sequentially. In addition, the largely accelerated phase conversion efficiency of the cathode at a higher temperature (from room temperature to 40 °C) contributes to its enhanced charge/discharge specific capacity, while the byproduct Li2S2O7 or Li3N irreversibly formed during the cycles limits its application performance at 0 °C. These conclusions would be very significant and useful for designing cathodes for Li-S batteries with excellent wide working temperature performance.

On the mechanisms of the influence of preliminary ionization on the plasma dynamics of nanosecond capillary discharges and the properties of discharge-based EUV lasers

In this paper, we present the results of numerical investigations into the influence of preionization on the properties of extreme ultraviolet (EUV) lasers based on nanosecond capillary discharges. Prior to application of the main current pulse, gas inside the capillary is usually preionized by a separate current pulse with longer duration and lower amplitude, which creates plasma with minimal density on the capillary axis and maximal at the capillary wall. Magnetohydrodynamic simulations were performed for a range of prepulse parameters that defined different degrees of inhomogeneity of this initial profile. It was found that the plasma density distribution at the start of the main current pulse affects the cylindrical shock wave that takes place during the compression stage of a capillary discharge: A lower degree of radial inhomogeneity results in a steeper front of the shock wave. It is further shown that a steeper wave front results in a more concave electron density profile moments before the shock wave collapses on the capillary axis, when the EUV laser pulse presumably takes place, which may lead to a decrease in the rate of refraction losses. The proposed interpretation of the obtained numerical results correlates well with the available experimental data on the dependence of EUV laser pulse intensity and duration on the preliminary pulse amplitude.

The dynamics of the formation of initial stages of a transverse nanosecond discharge with an extended slot cathode in argon

The dynamics of the main characteristics of a limited nanosecond discharge in an extended slot cathode in argon at the values of the applied voltage to the electrodes close to the values of the voltages of the formation of a volume discharge are studied by numerical simulation. It is shown that this type of discharge can be used to create an extended dense plasma column with a high density of charged and excited particles. The analysis of the spatiotemporal dynamics of development of the electron density and the electron energy distribution function was carried out. It is shown that the high-energy electrons are formed at the front of the ionization wave due to the hollow-cathode effect.

Thermal phenomena in electrohydrodynamic (EHD) drying

In this work, we explored the effect of AC corona discharge on water evaporation in a strong electric field by using a multipin-dielectric-plate EHD system. Our experiments demonstrated that the AC corona discharge could produce a significant amount of heat because of the Joule and dielectric heating of the dielectric barrier. When the electric field strength was below the ionization point and current density did not exceed 1 mA/m2, the heating was not substantial. At the initial stage of corona discharge with the current density below 10 mA/m2, the cooling effect of evaporation compensated the Joule heating of the dielectric barrier, keeping wet material surface below wet-bulb temperature. With a current density above 10 mA/m2, the AC heating effect became dominant. At 40 kV applied voltage and current density of 38 mA/m2, the temperature of the dielectric increased from 22 °C to 25 °C and the material surface reached wet-bulb temperature. A theoretical model of the relationship between material temperature, electric field strength, discharge current and drying rate in EHD drying was developed and experimentally verified.

Optimising Outpatient Pharmacy Staffing to Minimise Patients Queue Time using Discrete Event Simulation

Background: To remain relevant in the customer-oriented market, hospitals must pay attention to the quality of services and meet customers' expectations from admission to discharge stage. For an outpatient customer, pharmacy is the last unit visited before discharge. It is likely to influence patient satisfaction and reflect the quality of hospital's service. However, at certain hospitals, the waiting time is long. Resources need to be deployed strategically to reduce queue time. Objective: This research aims to arrange the number of staff (pharmacists and workers) in each station in the pharmacy outpatient service to minimise the queue time.Methods: A discrete simulation method is used to observe the waiting time spent at the pharmacy. The simulation run is valid and effective to test the scenario. Results: It is recommended to add more personnel for the non-compounding medicine and packaging to reduce the waiting time by 22.41%Conclusion: By adding personnel to non-compounding and packaging stations, the system performance could be improved. Cost-effectiveness analysis should be done to corroborate the finding. Keywords: Discrete Event Simulation, Hospital, Outpatient Service, Pharmacy Unit, System AnalysisBackground: To remain relevant in the customer-oriented market, hospitals must pay attention to the quality of services and meet customers' expectations from admission to discharge stage. For an outpatient customer, pharmacy is the last unit visited before discharge. It is likely to influence patient satisfaction and reflect the quality of hospital's service. However, at certain hospitals, the waiting time is long. Resources need to be deployed strategically to reduce queue time. Objective: This research aims to arrange the number of staff (pharmacists and workers) in each station in the pharmacy outpatient service to minimise the queue time.Methods: A discrete simulation method is used to observe the waiting time spent at the pharmacy. The simulation run is valid and effective to test the scenario. Results: It is recommended to add more personnel for the non-compounding medicine and packaging to reduce the waiting time by 22.41%Conclusion: By adding personnel to non-compounding and packaging stations, the system performance could be improved. Cost-effectiveness analysis should be done to corroborate the finding. Keywords:Discrete Event Simulation, Hospital, Outpatient Service, Pharmacy Unit, System Analysis