Increase In Discharge Rate Research Articles

Study on Discharge Dynamics and Droplet Characteristics of Various Nozzle Types for Pesticide Application

This research is aimed at reducing the environmental impact and increasing the efficiency of pesticide application by examining the effects of nozzle type and operating pressure on spray characteristics and discharge rate. Prevalent challenges of applying pesticides had been the subject of prior studies, but the relationships between nozzle types [flat fan, hollow cone, and flower (8-hole)] and operating pressures (2, 3 and 4 kg cm-2) were not widely recognized for greenhouses. This research gap necessitated an experimental approach, measuring spray deposition and discharge rate across three nozzles using a Malvern Spraytec droplet analyzer and spray patternator. Specific surface area (SSA), volume mean diameter [D(4,3)], Sauter mean diameter [D(3,2)], droplet size distribution (Dv10, Dv50, and Dv90), span were characterized and measured. Data were analyzed using analysis of variance (ANOVA) and Tukey's Honest Significant Difference (HSD) tests to determine significant difference between factors for nozzle selection. The results showed that increasing working pressure of flat fan nozzle from 2 to 4 kg cm-2 led to smaller droplets sizes, with Dv10, Dv50 and Dv90 decreasing from 85.61 to 66.41 µm, 165.33 to 142.80 µm, and 424.83 to 376.16 µm, respectively. Increase in SSA correspondingly from 0.387 to 0.524 m² cc-1, indicates more surface area available per unit volume of pesticides. It was found that with increase in discharge rate from 1045.69 to 1360.01 mL min-1, there was a significant increase in pesticide volume delivered. These findings provide important information for enhancing pesticide application procedures by highlighting the significance of carefully choosing operating pressures and nozzle types to establish a balance between spray efficacy and environmental considerations.

Electrochemical Study on Rate Characteristics of All-Solid-State Batteries

All-solid-state batteries (ASSBs) are next-generation batteries expected to significantly improve safety and energy density by replacing the liquid electrolyte of conventional lithium-ion batteries (LIBs) with a solid electrolyte. Although research and development for the commercialization of ASSBs are actively ongoing, many challenges remain to be addressed. In particular, the rate characteristic is directly related to the duration of discharge, which is a must-have performance for its use as a power source for transportation systems, including electric vehicles. Unlike conventional LIBs, where porous electrodes are fabricated and then filled with liquid electrolytes, ASSBs use a solid electrolyte with low fluidity, so the electrode components such as solid electrolyte, active materials, and binders are mixed at once to fabricate a composite electrode. The size, size distribution, and proportion of the solid electrolyte determine its occupancy within the composite electrode, which critically influences the lithium-ion transport through the electrolyte within the electrode. For example, increasing the proportion of active material within the electrode to achieve high energy density reduces the electrolyte content, making lithium-ion transport more difficult, leading to increased overvoltage and poor rate characteristics in the battery. In addition, during repeated cycling of ASSBs, the volume changes of the active material are not well accommodated by the solid electrolyte, inevitably causing stress at the active material | electrolyte interface. If this stress exceeds the fracture stress, the interfacial contact deteriorates. Particularly, for Ni-rich layered oxides, the most prominent cathode materials currently, rapid volume changes due to H2-H3 phase transitions at high voltage can lead to contact loss at the interface and isolation of the active materials. This increases resistance and the associated overvoltage, significantly degrading the rate characteristics of batteries. To improve the rate characteristics of ASSBs, various theoretical analyses under different design conditions of composite electrode have been attempted. However, the complexity of lithium transport within the composite electrode during high-rate charge and discharge makes it difficult to accurately simulate and understand rate characteristics. To fully understand the rate characteristics, it is necessary to non-destructively track ion transport within the electrode in real-time during battery operation. However, to the best of our knowledge, there is very few studies on this.In this study, we electrochemically investigate the lithium transport behavior inside the composite electrode during high rate operation to understand the high rate characteristics of ASSBs. For the analysis, an ASSB with a sulfide-based solid electrolyte and a Ni-rich cathode was used, and the rate performance was firstly assessed by galvanostatic rate capability test (GRCT). Incremental capacity (dQ/dV) analysis of the discharge curves at high rate discharges, where the capacity decreases rapidly, showed that the dQ/dV peak intensity significantly decreased and the peak shifted in the cathodic direction. Based on the experimental results, we proposed that the tendency of the dQ/dV curve to change with increasing rate is attributed to the incomplete reaction of the active material due to the high overvoltage during high-rate discharge. To further analyze this, the interfacial resistance was obtained by two methods, stationary electrochemical impedance spectroscopy (SEIS) under open circuit state and dynamic electrochemical impedance spectroscopy (DEIS) under various discharge rates, and the obtained resistance values were comparatively analyzed. The interfacial resistance from SEIS showed an asymmetrical U-shaped curve with a minimum value at approximately mid-level depth of discharge (DoD). On the other hand, for the interfacial resistance from DEIS, the shape of the resistance change with DoD was generally similar to that of the SEIS, but it was found that the DoD with the minimum resistance gradually shifted to higher discharge states with increasing discharge rate. The discrepancies between the results obtained in the SEIS and DEIS were discussed in terms of the uneven degree of lithiation of the active material and the resulting heterogeneity in interfacial resistance. By considering the experimental/analytical results of this study and previous theoretical analysis of high rate operation in the literature, it was proposed that kinetic limitations, such as uneven lithiation of active material and poor supply of lithium ions in the direction of the electrode depth during high discharge rate, limited the utilization of cathode, leading to a sharp drop in cell potential and degradation of rate characteristics. In this work, an electrochemical approach to analyze the rate characteristics of ASSBs will be presented, and the rate-limiting mechanisms of ASSBs will be discussed from the reaction heterogeneity perspective.

Electrochemical and Thermal Analysis of Lithium‐Ion Battery Pack With Different Cell Configurations

ABSTRACTThe primary purpose of this research is to analyze and evaluate the effects of various discharge rates and cell configurations on the electrochemical and thermal behavior of a Li‐ion battery pack that is exposed to ambient air throughout the discharge process. The three‐dimensional numerical model is designed to accomplish this purpose and discusses two different cases. While the discharge rate is changed from 0.5 C to 2 C (stepping by 0.5 C) for each cell configuration considered in the first case, the numerical solutions are obtained for the various cell configurations (6S4P and 8S3P) by keeping the discharge rate constant at 1 C. The results obtained from these solutions show that the discharge rate affects a considerable amount of the battery performances and discharge times of the battery packs, activation, and ohmic losses occurring inside each battery cell. Moreover, 6S4P discharges over a longer period (about 25%) than 8S3P. While both activation and ohmic losses decrease with the increase of discharge rate, these losses remain almost constant at 0.5 C discharge rate in all analyzed conditions. As a result, having a battery pack with a long discharge time while maintaining low temperatures is useful and desired. With this in mind, while evaluating battery packs, the 6S4P battery pack looks to have the best arrangement.

Outcomes by Race and Ethnicity Following a Medicare Bundled Payment Program for Joint Replacement

The Comprehensive Care for Joint Replacement (CJR) model, a traditional Medicare bundled payment program for lower-extremity joint replacement, is associated with care for patients outside traditional Medicare. Whether CJR model outcomes have differed by patient race or ethnicity outside of traditional Medicare is unclear. To evaluate outcomes associated with the CJR model among Hispanic patients not enrolled in traditional Medicare. This cohort study used hospitalization data from California's Patient Discharge Dataset for all patients who underwent lower-extremity joint replacement in California between January 1, 2014, and December 31, 2017. In California, 3 metropolitan statistical areas (MSAs) were randomly selected to participate in CJR in April 2016. Hospitals not participating in other Medicare Alternative Payment Models were included in the treated group if they were in these 3 MSAs and in the control group if they were in the remaining 23 MSAs. The data analysis was performed between October 1 and December 31, 2023. Comprehensive Care for Joint Replacement program implementation. The main outcomes were hospital length of stay and home discharge rates by race and ethnicity. Home discharge status included self-care, the use of home health services, and hospice care at home. Event study, difference-in-differences, and triple differences models were used to estimate differential changes in health care service use by race and ethnicity for patients in the treated MSAs compared with the control MSAs before vs after CJR implementation. Of 309 834 hospitalizations (patient mean [SD] age, 68.3 [11.3] years; 60.6% women; 14.8% Hispanic; 72.4% non-Hispanic White), 48.0% were in treated MSAs and 52.0% in control MSAs. The CJR program was associated with an increase in home discharge rates for patients without traditional Medicare coverage; however, the increase differed by patient race and ethnicity. The increase was 0.05 (95% CI, 0.02-0.08) percentage points higher for Hispanic patients with Medicare Advantage and 0.03 (95% CI, 0.01-0.04) percentage points higher for Hispanic patients without Medicare compared with their non-Hispanic White counterparts. This cohort study shows that CJR program outcomes differed by race and ethnicity for patients covered outside traditional Medicare, with home discharge rates increasing more for Hispanic compared with non-Hispanic White patients. These findings suggest the importance of considering differential outcomes of Medicare payment policies for racial and ethnic minority patient populations beyond the initially targeted groups.

Representation of bulk water flow in the goldfish (Carassius auratus) midbrain.

With the mechanosensory lateral line system, fish and semi-aquatic amphibians detect water movements and pressure gradients. Hydrodynamic information picked up by the lateral line receptors is relayed via peripheral nerves to the lateral line brainstem and from there to the midbrain torus semicircularis. Most prior electrophysiological studies of the lateral line were done under still-water conditions, even though natural environments encountered by fish include bulk-flow. Flow velocity and direction sensing are likely important to fish as they navigate variable, turbulent environments, but to date, only few studies have gathered information on the processing of bulk water flow by midbrain units. Here, we recorded from lateral line units in the torus semicircularis while presenting various bulk flow velocities in anterior-to-posterior and posterior-to-anterior flow directions. We studied (1) the temporal spike patterns of mechanosensory midbrain units, (2) the processing of bulk water flow velocity by these units, and (3) the processing of bulk water flow direction. We found that midbrain mechanosensory units alter their discharge rate during bulk water flow - some units responded to flow by increasing their discharge rate but did not vary this rate significantly with flow velocity, while others exhibited increasing discharge rates with increasing flow velocity. Units directly coding for flow direction were not found.

Changes in motor unit behaviour across repeated bouts of eccentric exercise.

Unaccustomed eccentric exercise (EE) is protective against muscle damage following a subsequent bout of similar exercise. One hypothesis suggests the existence of an alteration in motor unit (MU) behaviour during the second bout, which might contribute to the adaptive response. Accordingly, the present study investigated MU changes during repeated bouts of EE. During two bouts of exercise where maximal lengthening dorsiflexion (10 repetitions × 10 sets) was performed 3weeks apart, maximal voluntary isometric torque (MVIC) and MU behaviour (quantified using high-density electromyography; HDsEMG) were measured at baseline, during (after set 5), and post-EE. The HDsEMG signals were decomposed into individual MU discharge timings, and a subset were tracked across each time point. MVIC was reduced similarly in both bouts post-EE (Δ27 vs. 23%, P=0.144), with a comparable amount of total work performed (∼1,300 J; P=0.905). In total, 1,754 MUs were identified and the decline in MVIC was accompanied by a stepwise increase in discharge rate (∼13%; P<0.001). A decrease in relative recruitment was found immediately after EE in Bout 1versus baseline (∼16%; P<0.01), along with reductions in derecruitment thresholds immediately after EE in Bout 2. The coefficient of variation of inter-spike intervals was lower in Bout 2 (∼15%; P<0.001). Our data provide new information regarding a change in MU behaviour during the performance of a repeated bout of EE. Importantly, such changes in MU behaviour might contribute, at least in part, to the repeated bout phenomenon.

Therapeutic effects of Tocilizumab on COVID-19

Critical lung damage and death are the most profound outcomes associated with the cytokine storm induced by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is well known that COVID-19 in many patients triggers hyperactivation of the immune system, resulting in the release of a diverse set of cytokine signal molecules in the pulmonary tissue, leading to a potentially lethal hyperinflammatory condition. One cytokine found to play a central role in this outcome is interleukin-6 (IL-6). Therefore, preventing IL-6 signaling could potentially improve patient outcomes. Tocilizumab is an IL-6 receptor agonist originally approved by the FDA to treat rheumatoid arthritis, which was found to be effective at reducing the mortality of patients with moderate to severe COVID-19 symptoms through prevention of the aforementioned induced cytokine storm. Clinical trials have supported this conclusion and will be addressed, such as the RECOVERY and COVACTA trials. Results have shown a decrease in mortality, as well as an increase in discharge rate. Future research is needed to elucidate the molecular mechanisms as well as the therapeutic roles of Tocilizumab on COVID-19 and similar pneumonia by virus infections.

Enhancement of battery thermal management effect by a novel MOF based composite phase change material

The introduction of phase change materials (PCMs) into battery thermal management systems (BTMS) can effectively enhance the cooling performance, safety and practical thermal management applications of lithium-ion batteries (LIBs). However, further study is needed to address the low heat conductivity and rapid phase change leakage of PCMs. This study proposed a metal–organic framework based shape-stabilized composite PCM (MOF/expanded graphite (EG) /multi-walled carbon nanotube (MWCNT) /paraffin wax (PW)) to construe battery cooling system, and its effect of battery thermal management is experimentally tested under various conditions. The results show the CPCM reveals a superior thermal management effect under varying ambient temperatures and discharge multipliers and outperforms natural convection. Even in the harsh environment of 40 °C and 3 C, the maximum temperature (Tmax) and Tmax difference (ΔTmax) of the CPCM-cooled module are 61.38 and 2.67 °C, which are 22 and 9 °C below the natural air-cooled module. Remarkably, the ΔTmax of the CPCM-cooled battery module in discharge decreases with the temperature rise at the discharge rate of 3 C, which is the exact opposite to the case of the air-cooled module. Moreover, the ΔTmax of CPCM-cooled module is 1.69, 1.84, 2.67 °C, all below the safe 5 °C at high temperatures (40 °C) as the discharge rate increases. The designed MOF-CPCM cooling system can effectively improve the temperature uniformity and thermal safety of the battery in harsh environments. Therefore, this novel MOF-based CPCM shows great promise in BTM.

Performance of solid particles as thermal storage media in thermal power flexibility retrofits: Effects of charging and discharging flow rates on single piece stacking bed

An innovative, efficient, and cost-effective energy storage method was introduced for retrofitting thermal power plants, which can be connected in series to scale up quickly (like a battery) and aimed to replace expensive, hazardous molten salts. Charging/discharging processes among steam and solid particles were investigated using energy storage devices with capacities in the tens of kilowatts. Results of the study confirm the excellent performance of steel waste as a thermal energy storage medium. Key findings include that the time required for complete charging decreases from 75 to 300 kg/h, taking 173, 128, 106, and 105 min, respectively. The most efficient charging occurs when the bed temperature is most inhomogeneous, taking 68, 42, 34, and 28 min for 75–300 kg/h. The highest average charging power and heat transfer coefficient are 5 kW and 210 W/(m2·K) at 300 kg/h. In addition, 145 kg/h achieves optimal speed and quantity coupling, resulting in the highest charging efficiency of approximately 84 %. Time-optimized and efficiency-optimized charging flows are given. Real-time efficiency shows that the poorest temperature uniformity corresponds to the highest charging efficiency, with 145 kg/h exhibiting the strongest thermal inertia and 75 kg/h the weakest. Higher flow rates improve internal heat transfer and reduce stratification, facilitating multiple charge-discharge cycles. At discharge rates of 50, 75, and 100 kg/h, steam production is sustained at approximately 30, 40, and 50 kg/h for 11, 7, and 7 min, respectively. Discharge efficiency increases with flow rate, rising from 30 % to 95 %. Phase transition region migrates at approximately 10∼20 mm/s across different discharge rates, with 75 kg/h showing the fastest discharge state. As the discharge rate increases, the phase transition region's total area proportion rises, reaching about 70 % at 100 kg/h. Research demonstrates the potential of this new energy storage medium for efficient and safe retrofitting of thermal power plants.

Experimental study on the effect of longitudinal ventilation on spill fire characteristics in sloped tunnels

A series of spill fire tests were carried out in a reduced-scale tunnel (6 m × 0.6 m × 0.45 m), considering different discharge rates (60–140 ml/min), ventilation rates (0∼1.26 m/s), and tunnel slopes (3 %, 5 %, 7 %). Some crucial characteristic parameters during the quasi-steady combustion stage of tunnel spill fires were analyzed, including the diffusion shape of the liquid fuel, mass burning rate per unit area, flame morphology and plume temperature, and the critical ventilation velocity. The results show that as the tunnel slope increases, the diffusion shape of the liquid fuel transitions from circular to an ellipse shape and then to rectangular or linear shape. Moreover, the mass burning rate per unit area decreases with increasing ventilation rates at low ventilation (V < 0.5 m/s), while it remains almost constant at high ventilation rates (V ≥ 0.5 m/s). This could be attributed to variations in flame tilt behavior under different ventilation conditions. Predictive models for the flame tilt angle and the vertical temperature distribution of tunnel spill fires under the effect of ventilation were further established and verified. Furthermore, the critical ventilation velocity of tunnel spill fires remains essentially unchanged as the discharge rate (or fire source power) increases. This phenomenon was explained by analyzing the resistance of the spill fire plume and the buoyancy generated by the smoke temperature. This work could serve as a critical reference for assessing disaster risks and executing emergency rescue operations during tunnel spill fires.

Quantitative measurement of thermal performance of a cylindrical lithium-ion battery

Measuring the thermal performance of lithium-ion battery cells is a critical task in the thermal design of electric vehicle battery packs. This study introduces a quantitative method to assess the thermal performance of cylindrical 21,700 cells considering heat loss, under conditions of both high and low temperature-rises. By supervising the cell’s outgoing heat-flux (heat loss), we thoroughly analyzed the differences in cell heat generation rates between high temperature-rise (HTR) and low temperature-rise (LTR) conditions. The results show that under LTR conditions, the cell heat generation exhibits a “fast-slow-fast” increasing trend, while under HTR conditions, it displays a U-shaped pattern. Notably, the mean cell heat generation rate increases with decreasing temperatures and increasing discharge rates, especially under LTR conditions, where it significantly outperforms that under HTR conditions. This method provides valuable insights for optimizing the thermal design of battery packs.

Experimental study on the influence of gas-blowing flow rate on the cold discharge characteristics of external ice-melting ice storage system

External ice-melting ice storage system has the advantage of fast cold discharge. However, the instability of outlet water temperature limits its practical application. In this paper, an experimental bench is built for testing cold discharge performance of the external ice-melting ice storage system combined with a gas-blowing device based on theoretical analysis. The influence of different gas-blowing flow rates on the vertical temperature distribution inside the ice storage tank, outlet water temperature, cold discharge rate, instantaneous cold discharge capacity, and total cold discharge capacity is analyzed and compared during the cold discharge process by experiments. The experimental results show that as the gas-blowing flow rate increases, the convective heat transfer between the water and ice in the water space of the ice storage tank is enhanced, the outlet water temperature decreases, and the cold discharge rate increases. Through comprehensive analysis, it is found that for a small external ice-melting ice storage system in this experiment, the outstanding comprehensive performance can be achieved with 1L/min gas-blowing flow rate, which. The average outlet water temperature during the latent heat phase is 1.9 °C lower and the cold discharge rate is 34.8 % higher than that without gas blowing.

Analysis of muck migration behavior and suction port extending forward performance in the working chamber of the slurry shield machine under clay stratum

This study aimed to solve the problem of clogging in the working chamber of a large-diameter slurry shield passing through the clay stratum. Numerical simulation and experimental methods were employed to investigate the migration behavior of the muck in the original working chamber structure. The impact of increasing the percentage of scouring flow and implementing the suction port extending forward method on the muck discharge performance was also investigated. The results indicated that raising the scouring flow percentage could not improve the muck discharge performance under the original structure. However, extending the suction port to 500 mm from the slurry gate resulted in a 75.19% increase in the muck discharge rate and an 84.70% reduction in muck accumulation at the bottom of the chamber. Moreover, closing the scouring pipelines V25 and V7 after extending the suction port forward allowed for more efficient use of the limited slurry flow. Finally, an optimized suction port extending forward method was proposed and successfully applied to alleviate the clogging issue.

Supraspinal, spinal, and motor unit adjustments to fatiguing isometric contractions of the knee extensors at low and high submaximal intensities in males.

Contraction intensity is a key factor determining the development of muscle fatigue, and it has been shown to induce distinct changes along the motor pathway. The role of cortical and spinal inputs that regulate motor unit (MU) behavior during fatiguing contractions is poorly understood. We studied the cortical, spinal, and neuromuscular response to sustained fatiguing isometric tasks performed at 20% and 70% of the maximum isometric voluntary contraction (MVC), together with MU behavior of knee extensors in healthy active males. Neuromuscular function was assessed before and after performance of both tasks. Cortical and spinal responses during exercise were measured via stimulation of the motor cortex and spinal cord. High-density electromyography was used to record individual MUs from the vastus lateralis (VL). Exercise at 70%MVC induced greater decline in MVC (P = 0.023) and potentiated twitch force compared with 20%MVC (P < 0.001), with no difference in voluntary activation (P = 0.514). Throughout exercise, corticospinal responses were greater during the 20%MVC task (P < 0.001), and spinal responses increased over time in both tasks (P ≤ 0.042). MU discharge rate increased similarly after both tasks (P ≤ 0.043), whereas recruitment and derecruitment thresholds were unaffected (P ≥ 0.295). These results suggest that increased excitability of cortical and spinal inputs might be responsible for the increase in MU discharge rate. The increase in evoked responses together with the higher MU discharge rate might be required to compensate for peripheral adjustments to sustain fatiguing contractions at different intensities.NEW & NOTEWORTHY Changes in central nervous system and muscle function occur in response to fatiguing exercise and are specific to exercise intensity. This study measured corticospinal, neuromuscular, and motor unit behavior to fatiguing isometric tasks performed at different intensities. Both tasks increased corticospinal excitability and motor unit discharge rate. Our findings suggest that these acute adjustments are required to compensate for the exercise-induced decrements in neuromuscular function caused by fatiguing tasks.

Improving Patient Outcomes Using Measures to Increase Discharge Rates to Home.

Background Post-acute care (PAC) centers are facilities used for recuperation, rehabilitation, and symptom management in an effort to improve the long-term outcomes of patients. PAC centers include skilled nursing facilities, inpatient rehabilitation facilities, and long-term care hospitals. In the 1990s, Medicare payment reforms significantly increased the discharge rates to PAC centers and subsequently increased the length of stay (LOS) amongthese patient populations. Over the last several years, there have been national initiatives and multidisciplinary approaches to improve safe discharge rates to home. Multiple studies have shown that patients who are discharged to home have decreased rates of 30-day readmissions, reduced short-term mortality, and an improvement in their activities of daily living. Objectives This study aimed to investigate how multidisciplinary approaches could improve a single institution's discharge rates to home. In doing so, we aim to lower hospital readmission rates, hospital length of stay, morbidity and mortality rates, and healthcare-associated costs. Methods A retrospective single-institution cohort study was implemented at Jersey Shore University Medical Center (JSUMC). Data from January 2015 to December 2019 served as the control period, compared to the intervention period from January 2020 to January 2024. Patients were either admitted to JSUMC teaching faculty, hospitalists, or "others," which is composed of various medical and surgical subspecialists. Interventions performed to improve home discharge rates can be categorized into the following: physician education, patient education, electronic medical record (EMR) initiatives, accountability, and daily mobility initiatives. All interventions were performed equally across the three patient populations. The primary endpoint was the proportion of patients discharged to home. Results There were 190,699 patients, divided into a pre-intervention group comprising 98,885 individuals and a post-intervention group comprising 91,814 patients. Within the pre-intervention group, the faculty attended to 8,495 patients, hospitalists cared for 39,145 patients, and others managed 51,245 patients. In the post-intervention period, the faculty oversaw 8,014 patients, hospitalists attended to 35,094 patients, and others were responsible for 48,706 patients. After implementing a series of multidisciplinary interventions, there was a significant increase in the proportion of patients discharged home, rising from 74.9% to 80.2% across the entire patient population. Specifically, patients under the care of the faculty experienced a more substantial improvement, with a discharge rate increasing from 73.6% to 84.4%. Similarly, the hospitalists exhibited a rise from 69.4% to 74.3%, and the others demonstrated an increase from 79.3% to 83.7%. All observed changes yielded a p-value < 0.001. Conclusions By deploying a multifaceted strategy that emphasized physician education, patient education, EMR initiatives, accountability measures, and daily mobility, there was a statistically significant increase in the rate of patient discharges to home. These initiatives proved to be cost-effective and led to a tangible reduction in healthcare-associated costsand patient length of stay. Further studies are required to look into the effect on hospital readmission rates and morbidity and mortality rates. The comprehensive approach showcased its potential to optimize patient outcomes.

The exploration of the internal homogeneities for a LiFePO4 pouch lithium-ion battery with a 3D electrochemical-thermal coupled model

Along with the battery charge/discharge processes, the migration of the Li ions inevitably leads to an inhomogeneous distribution of the battery internal electrochemical and thermal characteristics, deteriorating the battery capacity and safety. In this work, the internal characteristics of a 20 Ah pouch LiFePO4 lithium-ion battery have been investigated based on a 3D electrochemical-thermal coupled model. It is found that the reduction of the particle size for either the cathode or anode would increase the battery capacity. Moreover, with the modulation of the thickness of cathode (Lpos) and convective heat transfer coefficient (h), the homogeneity of solid lithium concentration and temperature has been optimized. A relatively smaller Lpos and an h higher than the critical value should be adopted. From the aspect of thermal distribution, as the discharge rate increases, the irreversible reaction heat always dominates, while the proportion of ohmic heat among the total heat increases, and the high temperature region always locates on the inner sides of the tabs. The methodology proposed in this work could be applied to pouch batteries with more repeated cell units and larger sizes.

Thermal hazard evaluation of 18650 lithium-ion batteries at various discharge rates

Lithium-ion batteries (LIB) provide high energy density, low self-discharge rate, long cycle life, and superior suitability for a wide range of applications, such as portable electronic devices, electric vehicles, and renewable energy systems. In this investigation, we prepared 18650 LIB cells with various discharging rates (1C, 2C, 3C, and 4C) using specified conditions for static discharging experiment, and recorded the battery discharge current (Idis), discharge time (tdis), central surface maximum temperature (Tmax), temperature fluctuation, discharge capacity (Cdis), discharge energy (Wdis), and voltage at different time intervals. We studied the association between the discharge rate and the thermal stability of LIB specimens. In the discharge process, it was observed that operating at an increased discharge rate exhibited a direct correlation with a higher temperature rise. The findings indicate that batteries prepared with a higher discharge rate exhibit greater instability in terms of inherent property. During the 4C discharge rate, the Tmax, Cdis, and Wdis values were 96.6 °C, 3.117 Ah, and 9.021 Wh, respectively. These results indicate that a discharging rate of 4C is inappropriate for batteries, while the discharging rates of 1C, 2C, and 3C are suitable in terms of thermal stability.

Assessing future changes in flood frequencies under CMIP6 climate projections using SWAT modeling: a case study of Bitlis Creek, Turkey

ABSTRACT Climate change is altering flood risk globally, with local variations prompting the necessity for regional assessments to guide the planning and management of water-related infrastructures. This study details an integrated framework for assessing future changes in flood frequencies, using the case of Bitlis Creek (Turkey). The precipitation and temperature simulations of 21 global circulation models (GCMs) from the coupled model intercomparison project phase 6 (CMIP6) are used to drive the developed soil and water assessment tool (SWAT) model in generating daily streamflow projections under the CMIP6 historical experiment and the shared socio-economic pathway (SSP) scenarios of SSP245 and SSP585. Five probability distribution functions are considered to calculate the 5-, 10-, 25-, 50-, 100-, and 500-year flood discharges for the historical period 1955–2010 and the future periods 2025–2074 and 2025–2099. The quantification of climate change impacts on the design discharges is based on the medians of the flood discharges obtained for the climate data of each GCM, using the best-fitted distribution functions. The findings illustrate significant increases in discharge rates, ranging from 21.1 to 31.7% for the 2025–2099 period under the SSP585 scenario, highlighting the necessity of considering changing climate conditions in designing water-related infrastructures.

Assessing watershed-scale impacts of best management practices and elevated atmospheric carbon dioxide concentrations on water yield

Changes in water yield are influenced by many intersecting biophysical elements, including climate, on-land best management practices, and landcover. Large-scale reductions in water yield may present a significant threat to water supplies globally. Many of these intersecting factors are intercorrelated and confounded, making it challenging to separate the factors' individual contributions to shaping local streamflow dynamics. Comprehensive hydrological models constructed based on a well-established understanding of biophysical processes are often employed to address these matters. However, these models rarely incorporate all relevant factors influencing local hydrological processes, due to the reliance of these models on the latest, albeit limited, state-of-the-art research. For instance, complexities inherent in watershed hydrology, which involve multilayered interactions among potentially many biophysical factors, leave the direct analysis of subtle impacts on water yields measured in-situ largely intractable. Therefore, we propose an innovative approach to assess impacts of elevated atmospheric CO2 concentrations and flow diversion terraces (FDTs) on stream discharge rates at the watershed scale. Initially, we use a comprehensive hydrological model to account for the impacts of major climatic and landuse/landcover factors on changes in field-acquired measurements of water yield. Next, we employ conventional and advanced statistical methods to decompose the residuals of model predictions to facilitate the identification of subtle influences promoted by increases in atmospheric CO2 concentrations and the application of FDTs in an agriculture-dominated watershed. Through this innovative approach, we find that FDTs contributed to a watershed-wide, net water-yield reduction of 188.0 mm (or 28.9 %) from 1992 to 2014. Ongoing increases in ambient CO2 concentrations, which are responsible for an overall reduction in a watershed-level assessment of stomatal conductance, have led to a minor increase in stream discharge rates during the same 23-year period, i.e., 0.45 mm of water yield per year, or 1.6 % overall. Streamflow reductions explicitly caused by regional warming in the area alone, on account of increased evapotranspiration, may be overestimated due to the opposing, synergistic effects on water yield associated with CO2-enrichment of the lower atmosphere and the annual application of FDTs.

Numerical simulation and structure optimization for hydraulic performance of perforated drip irrigation emitters

ABSTRACT The perforated drip irrigation emitter (PDIE) is a novel drip irrigation emitter incorporating multiple energy dissipation mechanisms, chiefly hedging, deflection, and friction. To characterize the influences of structural parameters and vortices on the hydraulic performance of PDIE, the discharge exponent, discharge rate, and emitter unit constant were analyzed via hydraulic performance experiments and numerical simulation. The key findings are: (1) Discharge exponents of PDIE ranged from 0.478 to 0.515; average high-pressure hydraulic performance exceeded low pressure by 4.882%. (2) The four key structural parameters impacted hydraulic performance from large to small as follows: the width of the perforation (a), the angle of the scalariform perforation plate (α), the distance of the two perforations (b), and the length of the channel cavity (c). Among them, the discharge exponent changes significantly with a and α. (3) Vortex-retaining PDIE exhibited a lower emitter discharge exponent versus vortex-removed versions. However, vortices increase discharge rate and reduce energy consumption of PDIE. After optimization, the emitter discharge exponent of the PDIE with the reserved vortex is 0.461, which is relatively improved by 3.556%. This study can provide a theoretical reference for the structural design of new drip irrigation emitters and functional analysis of vortices.