Improve Discharge Efficiency Research Articles

SOC estimation based on the gas‐liquid dynamics model using particle filter algorithm

Lithium-ion battery state of charge (SOC) estimation is the basis for other state estimations in electric vehicle (EV) battery management systems. Accurate SOC estimation can prevent overcharge and discharge of the battery, improve discharge efficiency and prolong cycle life. A high-precision SOC estimation method based on the gas-liquid dynamics (GLD) model is presented. The standard particle filter (PF) and the unscented particle filter (UPF) algorithm are successively used for optimizing and improving the chattering problem of the original GLD model. The results show that the two kinds of PF algorithms can effectively solve the chattering problem of the GLD model and improve the estimation accuracy. Among them, UPF has higher accuracy and the maximum estimation error is less than 2%. The PF method for estimating SOC introduced in this paper has the characteristics of high precision and large amount of calculation. Due to the above characteristics, this method can be used as a cloud SOC calculation method to periodically correct the local SOC of the vehicle.

Scalable self-assembly interfacial engineering for high-temperature dielectric energy storage

SummaryFlexible polymer dielectrics which can function well at elevated temperatures continue to be significant in harsh condition energy storage. However, state-of-the-art high-temperature polymers traditionally designed with conjugated structures for better thermal stability have compromised bandgaps and charge injection barriers. Here, we demonstrate a self-assembled polyvinyl alcohol (PVA)/montmorillonite (MMT) coating to impede charge carriers injecting into the polyimide (PI) polymer film. The anisotropic conductivity of the 2D nanolayered coating further dissipates the energy of charges through tortuous injection pathways. With the coating, high field pre-breakdown conduction measurement and space-charge profiling of PI films reveal a clear shifting of the dominant mode of conduction from the bulk-limited hopping to Schottky-injection limited conduction. The coating thus imparts PI films with a significantly suppressed electrical conduction (∼10×), and substantially improved discharge efficiency (7×) and energy density (2.7×) at 150°C. The facile and scalable flow-induced fabrication unleash enormous applications for harsh condition electrification.

Discharge effectiveness of thermal energy storage systems

The use of air as heat transfer fluid and a packed bed of rocks as storage medium for a thermal energy system (TES) can be a cost-effective alternative for thermal applications. Here, a porous media turbulent flow (standard k-ε) and heat transfer (local thermal non-equilibrium) model is used to simulate the discharge cycle of such system. Temperature fields of corresponding charging cycles are used as initial conditions. Effects of varying mass flow rates (Re number), porosity, permeability (Da number), thermal conductivity ratio and thermal capacity ratio on the effectiveness of the discharge are compared. The examination of these effects indicated that increasing the mass flow rate improved the effectiveness of the discharge, which was not seen for the charging cycle. Also, increasing porosity improved discharge efficiency more significantly than it did in the charging cycle. In both charge and discharge cycles the effect of permeability is significant and reducing Da number improved temperature stratification and efficiencies. The effect of the thermal conductivity ratio was mostly seen on the outlet temperatures, where lower ratios allowed for higher temperature values. Increasing the thermal capacity ratio improved charging effectiveness but, on the discharge cycle, cycle this effect was reduced. Moreover, for lower Re number flows, increasing this ratio reduced efficiency indicating that the mass flow rate should be matched carefully with the thermal capacity of the system. All these effects have important implications which should be taken into consideration when designing an effective thermal energy storage system.

Focusing hospitalist roles on either admitting or rounding facilitates unit-based assignment and is associated with improved discharge efficiency

ABSTRACT Background Unit-based teams may improve care delivery for hospitalized patients but can be challenging to implement broadly across all acute care units in a hospital. Objective To determine the effect of a Lean-guided transition to hospital-wide unit-based assignment on care delivery outcomes. Design, setting, and participants The study was a retrospective time-series with primary outcomes of discharge efficiency, 30-day readmissions, and length of stay, performed at a 336-bed tertiary academic referral hospital in the Pacific Northwest with approximately 17,000 admissions annually. Intervention Implementation of a Lean-guided quality improvement intervention included division of hospitalist duties into ‘admitters’ and ‘rounders,’ with simulated patient flow exercises to determine the optimal staffing model. Main outcomes and measures Discharge efficiency (number of patients discharged by hospitalists divided by the number of hospitalist patient encounter days per month) and 30-day readmissions were compared using the t-test or chi-square, and length of stay was analyzed in a multivariate time-series regression model. Results The intervention was associated with a significant improvement in discharge efficiency, by 0.014 (from 0.168 to 0.181) discharges/encounter (95% CI = 0.024, 0.004), p = 0.009. Mean length of stay decreased by 0.98 days (95% CI 0.50, 1.47) after adjustment for patient age, patient type (medical versus surgical), critical care admissions, and discharge disposition, without a corresponding change in 30-day readmission rate (12.2% (1948/15,902) pre-intervention to 11.7% (397/3379) post-intervention (p = 0.42)). Conclusions Dividing hospitalist roles into admitters and rounders enabled implementation of unit-based teams across the hospital, with corresponding improvements in discharge efficiency and length of stay.

Luminous spot distribution of vacuum arc discharge with deuteride cathode

Vacuum arc discharges with deuteride cathode have many applications, such as nondestructive examination, oil logging, and neutron activation analysis. Deuteride cathode releases many gases during discharge, which is quite different from metal cathode. The discharges display some unique characteristics. A maguifying lens and an ICCD camera are used to observe the luminous spots of vacuum arc discharge. The space resolution of this system is about 5 μm, and the time resolution is about 2 ns. The arc current has a full width at half maximum (FWHM) of about 0.9 μs, and its waveform is half cycle sinusoidal. The results show that the luminous spots merge together into a big one in most cases. Sometimes there are two or more luminous spots due to droplets. The area of the luminous spot grows as arc current increases. The cathode spots’ merging is helpful to increase plasma density and improve discharge efficiency.

Reducing Discharge Delay Through Resident-Pharmacist Colocation: A Pilot Study.

Discharge delay of hospitalized patients is costly, inefficient, and can impede care of pending admissions. Through pharmacist colocation and daily discharge medication reconciliation meetings, we aimed to improve discharge efficiency and decrease the number of electronic pages. We conducted a quality improvement initiative on the family medicine inpatient teaching service at a large academic medical center using two interventions: colocation and daily discharge medication reconciliation meetings of pharmacist and family medicine residents. We assessed: (1) discharge delay, defined as the time between discharge order and pharmacist's completion of discharge medication reconciliation and patient education; (2) the number of electronic messages between the pharmacist and family medicine team, assessed 1 month before and 1 month after implementation of the interventions. We also assessed team members' postinitiative views on collaboration, discharge safety, and timeliness, and knowledge acquisition using three 5-point Likert statements. Ninety-five preintervention and 54 postintervention patients met eligibility criteria. Discharge delay prior to intervention was 72.7±58.4 minutes and 47.6±37.4 minutes postintervention. The number of electronic messages between pharmacist and family medicine team pager decreased from 118 to 14 during the months studied. Team members felt collaboration, safe and timely discharges, and acquisition of new knowledge improved. Colocation of workspaces and daily medication reconciliation meetings were associated with decreased discharge delay and decreased pages between team members. Further study is needed to assess its reproducibility, impact on resident education and patient satisfaction, cost-effectiveness, and ability to scale to other services.

Evaluation of Discharge Coordinators and Their Effect on Discharge Efficiency and Preparedness.

A discharge coordinator role was evaluated to determine if it resulted in more discharges before noon, decreased length of stay, and prepared families for self-care at home. This evaluation took place at a pediatric cardiac care unit. Discharges before noon, reasons for delays, and length of stay were analyzed before and after the discharge coordinator role. Parental knowledge assessments were completed a week after discharge. A nursing survey measured satisfaction with the patient discharge process. Rates of discharge before noon increased (31.68% vs. 44.39%) and length of stay decreased (97.16 vs. 85.24 hr) with a discharge coordinator. Parental knowledge assessment revealed fewer deficits, and nurses were satisfied. A dedicated person to coordinate patient discharge needs can improve discharge efficiency and increase the likelihood of successful self-care at home. Further evaluation is needed to determine how this role impacts readmission.

An Iterative Quality Improvement Process Improves Pediatric Ward Discharge Efficiency.

Discharge of hospitalized pediatric patients may be delayed for various "nonmedical" reasons. Such delays impact hospital flow and contribute to hospital crowding. We aimed to improve discharge efficiency for our hospitalized pediatric patients by using an iterative quality improvement (QI) process. Opportunities for improved efficiency were identified using value stream mapping, root cause, and benefit-effort analyses. QI interventions were focused on altered physician workflow, standardized discharge checklists, and physician workshops by using multiple plan-do-study-act cycles. The primary outcome of percentage of discharges before noon, process measure of percentage of discharges with orders before 10 am, and balancing measures of readmission rate, emergency department revisit rate, and parent experience survey scores were analyzed by using statistical process control. The secondary outcome of mean length of stay was analyzed using t tests and linear regression. Implementation of our interventions was associated with special cause variation, with an upward shift in mean percentage of discharges before noon from 13.2% to 18.5%. Mean percentage of patients with discharge orders before 10 am also increased from 13.6% to 23.6% and met rules for special cause. No change was detected in a control group. Adjusted mean length of stay index, 30-day readmissions, and parent experience survey scores remained unchanged. Special cause variation indicated a decreased 48-hour emergency department revisit rate associated with our interventions. An iterative QI process improved discharge efficiency without negatively affecting subsequent hospital use or parent experience. With this study, we support investment of resources into improving pediatric discharge efficiency through value stream mapping and rapid cycle QI.

High-Energy-Density Ferroelectric Polymer Nanocomposites for Capacitive Energy Storage: Enhanced Breakdown Strength and Improved Discharge Efficiency

Emerging dielectric composites consisting of polymer and ceramic nano-inclusions or several polymers facilitate the development of capacitive energy storage materials, as they can preserve high breakdown strength and exhibit enhanced dielectric constant. Ferroelectric poly(vinylidene fluoride) (PVDF) and its copolymers have been intensively studied as the matrices because of their high intrinsic dielectric constant and breakdown strength. Here, we review the recent advances on improving the energy density of PVDF-based composite dielectrics. It is concluded that, promotion of energy density is mainly established on enhanced breakdown strength and improved discharge efficiency. The microstructure design, material performance, and mechanism associated with these parameters are described. Perspectives for future development on PVDF-based nanocomposites and application of other potential polymer matrices are presented at last.

Use of a daily rounding checklist on the Clinical Teaching Unit improves interdisciplinary communication around discharge

Abstract BACKGROUND As the care needs of the paediatric inpatient population become increasingly complex, demands for hospitalization and efficient patient flow have resulted in the need for increased attention to discharge processes. Inefficient discharges impact flow throughout the healthcare system, extend length of stay, increase health care costs and decrease patient satisfaction. As a large inpatient service with high staff turnover, our Clinical Teaching Unit (CTU) experiences considerable variability in approach to discharge planning. Prior work at our institution has recognized inconsistent practice and gaps in communication around discharge planning as challenges to efficient patient discharge. OBJECTIVES Using quality improvement (QI) methodology, we aimed to decrease discharge delays on CTU, by implementing a process to identify and document patient specific discharge criteria. By focusing on discharge criteria, we sought to improve communication regarding discharge goals and patient readiness between care members, encouraging early discharge planning. DESIGN/METHODS We implemented a standardized CTU rounding checklist for use during daily inpatient rounds. On this checklist, physicians were instructed to document clear, patient-specific discharge criteria. Use of the checklist was encouraged through multiple avenues, including announcements at educational events, real time feedback on use to the front-line care teams and a monthly competition between resident teams. Through Plan-Do-Study-Act (PDSA) cycles, we collected feedback from the multidisciplinary team, and the checklist underwent multiple iterations to optimize use. CTU inpatient rounds were observed weekly and outcome, process and balance measures were collected. RESULTS With implementation of the checklist, a cultural shift towards explicit, thoughtful discussion of discharge criteria and planning was observed on daily patient rounds. Identification of patient specific discharge criteria increased from less than 30% to over 90% after implementation of the checklist. The purposeful documentation of discharge criteria received positive nursing feedback, and nursing awareness of discharge goals improved from 20–30% to over 70%. Improvements were sustained over a six-month period. CONCLUSION This QI project utilized a daily rounding checklist to engage care teams in purposeful conversations around discharge on rounds. By documenting patient-specific discharge criteria, interdisciplinary communication was improved and bedside nurses felt better informed of discharge goals. Future project directions include the development of diagnosis specific standardized discharge criteria, exploration of specific discharge barriers, and identification of institution-specific resources that may help alleviate these delays to further improve discharge efficiency.

Direct decomposition of CO2 using self‐cooling dielectric barrier discharge plasma

AbstractAs a greenhouse gas, carbon dioxide (CO2) is one of the major causes of global warming. The effective control of CO2 emission has become a major global concern. To reduce CO2 emission in the environment and to maximize the use of CO2, a self‐cooling wire‐cylinder dielectric barrier discharge (DBD) plasma reactor was used to decompose CO2 at ambient conditions, and the results were compared with a common wire‐cylinder DBD reactor. Results indicated that in the said plasma reactor, circulating water could obviously improve discharge efficiency through taking away heat that was generated during plasma discharge process, and a more stable and homogeneous discharge was easier to obtain. The CO2 decomposition rate was 26.1% without using any catalysts and discharge mediums or modifying electrodes, and this value was significantly higher than that in the common wire‐cylinder DBD reactor (10.1% CO2 decomposition rate). Moreover, the CO2 decomposition rate could reach up to 35.8% when N2 was added (volume ratio ). © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Giant Energy Density and Improved Discharge Efficiency of Solution-Processed Polymer Nanocomposites for Dielectric Energy Storage.

Large-aspect-ratio composite nanofibers with interior hierarchical interfaces are employed to break the adverse coupling of electric displacement and breakdown strength in flexible poly(vinylidene fluoride-hexafluoropropylene) nanocomposite films, a small loading of 3 vol% BaTiO3@TiO2 nanofibers gives rise to the highestenergy density (≈31.2 J cm(-3)) ever achieved in polymer nanocomposites dielectrics.

Review of Molten-Salt Thermocline Tank Modeling for Solar Thermal Energy Storage

Molten-salt thermocline tanks are a low-cost option for thermal energy storage in concentrating solar power systems. A review of previous experimental and numerical thermocline tank studies is performed to identify key issues associated with tank design and performance. Published models have shown that tank discharge performance improves with both larger tank height and smaller internal filler diameter due to increased thermal stratification and sustained outflow of molten salt with high thermal quality. For well-insulated (adiabatic) tanks, low molten-salt flow rates reduce the axial extent of the heat-exchange region and increase discharge efficiency. Under nonadiabatic conditions, low flow rates become detrimental to stratification due to the development of fluid recirculation zones inside the tank. For such tanks, higher flow rates reduce molten-salt residence time inside the tank and improve discharge efficiency. Despite the economic advantages of a thermocline tank, thermal ratcheting of the tank wall remains a significant design concern. The potential for thermal ratcheting is reduced through the inclusion of an internal thermal insulation layer between the molten salt and tank wall to diminish temperature oscillations along the tank wall. Future research directions are also pointed out, including combined analyses that consider the solar receiver and power generation blocks as well as optimization between performance and economic considerations.

Formation of hydrophobic coating on PMMA surface using unipolar nanosecond-pulse DBD in atmospheric air

Abstract Dielectric barrier discharge (DBD) can modify the material surface and result in complicated physical and chemical reactions to improve the surface hydrophilicity, which is proved to be an effective method for surface modification. Compared with the traditional ac-excitation DBD, the DBD using unipolar pulses can avoid local overheat of microdischarges and can improve discharge efficiency under some conditions. In this paper, DBD excited by repetitive unipolar nanosecond generator was used to improve the hydrophobicity of Plexiglass (PMMA) surface by means of the interaction between air plasma and silicone oil. The output voltage had a rise time of 40 ns and a full width at half maximum of about 70 ns. The surface hydrophobicity of the PMMA, before and after the surface modification, was evaluated via the contact angle measurement under different experimental conditions. The values of the contact angle shown in this paper were the average of eight measured values, and the standard deviations were also calculated. The surface energy including polar and dispersion components was calculated using the measured average contact angles of distilled water and polyethyleneglycol. The results showed that, as the increase of the discharge voltage, the contact angle increased but the surface energy decreased. With the increase of treatment time, the water contact angle of the modified surface increased at the beginning, and it would reach to a maximum at 7.5 min treatment, and then decreased. The effect of pulse frequency on the modification results was different at various treatment times. In addition, the possible physical and chemical reaction among the DBD plasma, silicone oil and the PMMA surface was discussed.

Optimization of design and characterization of a novel micro-pumping system with peristaltic motion

In this work, we present a novel design of peristalsis based micro pump with optimized fluid chambers possessing improved discharge efficiency per unit volume of the pumping architecture and reduced reverse flow. Such designs are very often important from the standpoint of blood cell sorting assays where a full delivery of fluid containment within the pumping chamber is critical. The paper uses FLUENT and COMSOL simulations to look at the fluid flow within the pumping chamber due to the deflecting actuator membrane during pumping cycle. The resulting effect of fluid-membrane interaction has been evaluated on different chamber designs for observing the lateral velocity distribution profile of fluid in the connecting channels. It has been observed through particle image velocimetry (PIV) that the optimized design has minimized chamber retainability with maximum deflection of the actuator membrane and minimum reverse flow component. Optimized geometrical profile formulated above was seen to allow the maximum contact area between actuating membrane and fluid containment thus reducing the problem of fluid retainability. Other experimental studies show that the new design has much lower percentage retainability of biological and other fluids contained within the chambers which makes it a comparatively high efficiency micropumping system with respect to the conventional design with circular membrane and chambers. The experimental evaluation of the new micro pump design has shown its least count to be 0.1 μl/min which is very well comparing with some of the other micropumping mechanisms like electro-osmotic, magneto-hydrodynamic mechanisms (Laser and Santiago in J Micromech Microeng 14:35, 2004; Iverson et al. 2008) and additionally provides better discharge efficiency per unit volume of the pumping architecture, lower retainability, minimized reverse flow and precise pumping of fluids.

A New Approach to Postpartum Rounds: Patient-Centered Collaborative Care Improves Efficiency

At our institution, traditional postpartum rounds were time consuming and inefficient with a low percentage (approximately 12%) of patients meeting the goal of being discharged by 11:00 am. A patient-centered collaborative care (PCCC) initiative was implemented to improve discharge efficiency, staff communication, and patient satisfaction. We investigated whether this paradigm shift to PCCC could improve clinical inefficiencies and timely discharge. The PCCC rounding system was created by a representative group of physicians, residents, nurses, case managers, and social workers. An intervention study was conducted to examine the impact of PCCC during which physicians, residents, medical students, nurses, case managers, and social workers made rounds together. Efficiency data were collected for patients whose infants were delivered by the obstetric service for a 1-month period before and 6months after implementing PCCC. Comparisons were made on the time of discharge and whether Foley catheter removal affected discharge time. χ(2) test, Wilcoxon 2-sample test, and Pearson correlation coefficient were used where appropriate. Three hundred five patients were included in this analysis, of which 156 participated in traditional postpartum rounds and 149 in PCCC rounds. Discharge efficiency significantly improved with PCCC rounds, with 20.8% of patients being discharged by 11:00 am as compared to 11.5% for traditional postpartum rounds (P = .03). Early Foley catheter removal was significantly associated with time to discharge order (Pearson correlation coefficient, 0.22; P = .01) and discharge time (Pearson correlation coefficient, 0.28; P = .002). Patient-centered collaborative care rounds improve the efficiency of postpartum care and discharge time.

A Prospective Evaluation of Discharge Efficiency in a University General Medical Unit

To determine whether a significant delay existed between the date when patients admitted to the University General Medical Unit (UGMU) at Princess Alexandra Hospital were considered to be medically fit for discharge, and the date of actual discharge from the ward, we undertook a prospective evaluation of all general medical patients admitted under the care of the UGMU physicians during the period 1 August to 31 October 1995 inclusive. A delay in discharge from the ward of more than one day occurred in 31.1% of patients, with the total number of days attributed to discharge delays representing 17% of all bed days. The two major causes of delays in discharge identified were insufficient institutional care beds and failure to plan patient discharges. Strategies proposed to improve discharge efficiency include early discharge planning, the provision of interim care wards and in the longer term, the provision of increased nursing home and hostel beds.