Circuit Resistance Research Articles

The Impact of Current in Resistance and Inductance of Rl Circuit in the Applications of Stochastic Differential Equations Using Caputo-Fabrizio Derivative

In this research article, the circuit thus designed here, can also be implemented in electrical substations, where in the reactors are used to control the flow of current, thereby regulating the inductance and resistance values. The optimum values of Inductance and Resistance found through this circuit, facilitates optimum flow of electricity, reduces the power loss due to inductance, also eases the burden on reactors in regulating power supply.

Positive end expiratory pressure and respiratory system resistance between self-inflating bag and T-piece resuscitator in a cadaveric piglet lung model.

In neonatal resuscitation, T-piece resuscitator (TPR) are used widely, but the evidence is limited for their use in infants born at term gestation. The aim of this study was to compare the delivered positive end expiratory pressure (PEEP) and respiratory system resistance (Rrs) using TPR and self-inflating bag (SIB) in a cadaveric piglet model. Cadaveric newborn piglets were tracheotomised, intubated (cuffed tube) and leak tested. Static lung compliance was measured. Positive pressure ventilation was applied by TPR and SIB in a randomized sequence with varying, inflations per minute (40, 60 and 80 min) and peak inspiratory pressures (18 and 30 cmH2O). PEEP was constant at 5 cmH2O. The lungs were washed with saline and static lung compliance was re-measured; ventilation sequences were repeated. Lung inflation data for the respiratory mechanics were measured using a respiratory function monitor and digitally recorded for both pre and post-lung wash inflation sequences. A paired sample t-test was used to compare the mean and standard deviation. The mean difference in PEEP (TPR vs. SIB) was statistically significant at higher inflation rates of 60 and 80 bpm. At normal lung compliance, mean difference was 1.231 (p = 0.000) and 2.099 (p = 0.000) with PIP of 18 and 30 cmH2O respectively. Significantly higher Rrs were observed when using a TPR with higher inflation rates of 60 and 80 bpm at varying lung compliance. TPR is associated with significantly higher PEEP in a compliant lung model, which is probably related to the resistance of the TPR circuit. The effect of inadvertent PEEP on lung mechanics and hemodynamics need to be examined in humans. Further studies are needed to assess devices used to provide PEEP (TPR, SIB with PEEP valve, Anaesthetic bag with flow valve) during resuscitation of the newborn.

Mixed Electric Field of Multi-Shaft Ship Based on Oxygen Mass Transfer Process under Turbulent Conditions

The theoretical basis for a multi-physics coupling modeling involving a turbulence flow field and a ship’s electric field was analyzed using the principles of electrochemistry and hydrodynamics. Considering the mass transfer of oxygen in the cathode reaction of electrochemical corrosion, the boundary element method was adopted to construct a corrosion electric field model for a multi-shaft ship under navigation. After dissecting the equivalent circuit resistance of the mechanical structure of a ship’s shaft, the initial phase difference of the equivalent resistance between different shafting systems of a multi-shaft ship was analyzed to reveal the regularity of variation of the ship corrosion mixed electric field, when the contact positions of the shaft grounding device were different. A ship model experiment was conducted to verify the correctness of the simulation model. As shown in the results, when the initial phase difference of two-shaft ship shafting equivalent resistance increased from 0° to 45°, 90°, 135°, and 180°, the amplitude of the ship’s mixed electric field varied by less than 3.7%, which was practically negligible. However, the amplitude of the ship’s shaft-rate electric field decreased by 8.30%, 25.4%, 50.2%, and 88.0%, respectively. Moreover, the minimum value of the shaft-rate electric field accounted for 4.11% of the maximum value. This significantly increased the difficulty of marine target detection based on electric field sensors.

Ultraelastic and High-Conductivity Multiphase Conductor with Universally Autonomous Self-Healing.

Next-generation, truly soft, and stretchable electronic circuits with material level self-healing functionality require high-performance solution-processable organic conductors capable of autonomously self-healing without external intervention. A persistent challenge is to achieve required performance level as electrical, mechanical, and self-healing properties optimized in tandem are difficult to attain. Here heterogenous multiphase conductor with cocontinuous morphology and macroscale phase separation for ultrafast universally autonomous self-healing with full recovery of pristine tensile and electrical properties in less than 120 and 900 s, respectively, is reported. The multiphase conductor is insensitive to flaws under stretching and achieves a synergistic combination of conductivity up to ≈1.5 S cm-1 , stress at break ≈4MPa, toughness up to >81MJ m-3 , and elastic recovery exceeding 2000% strain. Such properties are difficult to achieve simultaneously with any other type of material so far. The solution-processable multiphase conductor offers a paradigm shift for damage tolerant and environmentally resistant soft electronic components and circuits with material level self-healing.

Identifying ecological corridors for wetland waterbirds in Northeast China

Ecological corridors have recently garnered increasing international attention as promising biodiversity conservation models to study the effects of climate change. However, very few studies have characterized waterbird ecological corridors and their responses to environmental variations. Here, a hybrid model approach combining the least resistance model and circuit theory was applied to identify ecological corridors for four kinds of waterbirds (Grus japonensis, Grus grus, Cygnus cygnus, Mergus squamatus) in Northeast China. This region contains many wetlands that are rich in waterbird species and are important habitats and breeding grounds for waterbirds on the East Asia-Australia migration route. Our findings demonstrated that the least cost routes of different waterbird species and their pinch points (i.e., areas exhibiting high waterbird transit and density) have the potential to become waterbird ecological corridors. However, we observed substantial differences in the number of least-cost paths and the structure and distribution of ecological corridor networks due to differences in the number and distribution of waterbird core habitat patches. The number and distribution of pinch points were also different. Over 85% of the waterbird occurrence points were not far from the least-cost routes or the pinch points, indicating that the detected least-cost routes and the pinch points were not only ecological corridors for waterbirds but also priority areas for the conservation of waterbird habitat networks. The methods proposed herein could thus be used as a basis for the identification of multi-species waterbird ecological corridors in other countries, as well as forest bird ecological corridors at other scales.

Research on isolation method of spacecraft reaction wheels using electromagnetic shunt damping

The spacecraft flywheel system is widely used in various space missions due to its cleanliness, high reliability and high control accuracy, such as spacecraft attitude control and large-angle turning maneuvers. However, current research agrees that the high-speed rotating flywheel system is one of the main sources of micro-vibration disturbances on spacecraft. In view of the variable speed characteristics of the flywheel, this paper proposes a new vibration isolation system based on Stewart vibration isolation platform and electromagnetic shunt damping (EMSD). Attempts to connect three circuits of pure resistance circuit, resistance-inductance circuit and resistance-inductance-capacitor circuit to the new vibration isolation system in order to improve the isolation performance. Through theoretical analysis and numerical simulation, the effect of circuit parameters on isolation performance of each circuit are studied. The results show that EMSD can significantly reduce the disturbance input of the flywheel, and frequency modulation can be achieved through the conversion circuit to avoid resonance.

Development and Delivery of an Electric Circuits Course Featuring Competency Based Assessment for First Year Engineering

Most common-core first year engineering programs in Canada include an introduction to electric circuits and electromagnetic physics. The launch of the RE-ENGINEERED first year program at the University of Saskatchewan has provided an opportunity to try something different in this arena. The RE-ENGINEERED program includes a “spine” of electric circuit analysis and the related physics that runs through both semesters of the first year.
 The modular and highly integrated structure of the RE-ENGINEERED program has allowed for accelerated courses that take advantage of timely learning in other courses. In the fall term, students are introduced to direct-current, resistive circuit analysis in a six-week, fifteen-contact-hour module. In the winter term, they experience an accelerated physics course which covers the electricity, magnetism, capacitance, and inductance concepts often taught in tandem with basic circuit analysis. The students then finish the winter term with an intensive course on alternating-current circuit analysis.
 The fall term course fully adopts the competency based assessment system of the RE-ENGINEERED program, and uses in-house-developed quizzes and tutorials on the most basic concepts and calculations to scaffold students to solving more complex circuit analysis problems. The course forgoes a hands-on lab component and focuses on circuit simulation using an open-source simulation package. Concurrent math and MATLAB courses introduce required linear algebra concepts just in time for use in the circuit analysis problems.
 This paper describes the development and delivery of the fall term course, including how the learning outcomes were synthesized and then used as the basis for the development of all other aspects of the course to ensure constructive alignment. Instructor and student impressions of the first delivery of the course are presented along how lessons learned will be applied to modify the course for future offerings.

PSUN187 Validation of a multi-frequency bioelectrical impedance analysis device for the assessment of body composition in older adults with type 2 diabetes

Abstract Background Aging and type 2 diabetes (T2DM) are associated with an increased risk of developing sarcopenia which is associated with poor outcomes and may necessitate specific treatment. Diagnosis of sarcopenia often requires the referral of patients to dual-energy X-ray absorptiometry (DXA) in specialized settings. Another available method for assessing body composition is direct segmental multi-frequency bioelectrical impedance analysis (DSMF-BIA). In this study, we examine the accuracy of a DSMF-BIA (InBody 770) for assessing body composition in older adults with T2DM when compared to DXA. Methods 84 older adults (49 women, age 71 ± 5 years. Body mass index 30 ± 5.6 kg /m2) with T2DM who were recruited for the CEV-65 study and had both DSMF-BIA and DXA assessments at baseline were included in the analysis. The main analysis included Bland-Altman plots and Intra Class Correlation Coefficients (ICC). Sub-analyses were performed according to gender and following 10 weeks of intervention (diet, circuit resistance training, and Empagliflozin). Results The leg lean mass results according to DSMF-BIA and DXA were 14.76 ± 3.62 kg and 15.19 ± 3.52 kg respectively, however, did not differ between devices according to Bland-Altman analyses (p=0.353). Assessment of appendicular skeletal mass index did not differ between DSMF-BIA and DXA (7.43 vs. 7.47 kg/m2; p=0.84; ICC=0.965, p<0.0001; bias of -0.068, p =0.595). The accuracy of DSMF-BIA was limited when estimating fat mass indices reflected by significant biases according to Bland-Altman analyses. Summary In a sample of older adults with T2DM the degree of agreement between DSMF-BIA and DXA, was high, supporting the use of DSMF-BIA for the diagnosis of low muscle mass. Better accuracy was observed when comparing parameters of lean mass versus parameters of fat mass. Gender as well as three common treatment modalities for T2DM did not modify the accuracy of the DSMF-BIA when compared to DXA. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Si-based self-programming neuromorphic integrated circuits for intelligent morphing wings

Unlike artificial intelligent systems based on computers, which must be programmed for specific tasks, the human brain can learn in real-time to create new tactics and adapt to complex, unpredictable environments. Computers embedded in artificial intelligent systems can execute arbitrary inference algorithms capable of outperforming humans at specific tasks. However, without real-time self-programming functionality, they must be preprogrammed by humans and will likely to fail in unpredictable environments beyond their preprogrammed domains. In this work, a Si-based synaptic resistor (synstor) was developed by integrating Al2Ox/TaOy materials to emulate biological synapses. The synstors were characterized, and their operation mechanism based on the charge stored in the oxygen vacancies in the Al2Ox material was simulated and analyzed, to understand the inference, learning, and memory functions of the synstors. A self-programming neuromorphic integrated circuit (SNIC) based on synstors was fabricated to execute inference and learning algorithms concurrently in real-time with an energy efficiency more than six-orders of magnitudes higher than those of standard digital computers. The SNIC dynamically modified its algorithm in a real-time learning process to control a morphing wing, thus successfully improving its lift-to-drag force ratio and recovering the wing from stall in complex aerodynamic environments. The synaptic resistor circuits can potentially circumvent the fundamental limitations of computers, thus providing a platform analogous to neurobiological network with real-time self-programming functionality for artificial intelligent systems.

Energy, exergy, exergoeconomic and exergoenvironmental analysis and optimization of a novel partially covered parabolic trough photovoltaic thermal collector based on life cycle method

Efficient utilization of solar energy could effectively alleviate dependence on fossil fuels and contribute to the ambitious target of carbon neutrality. This study first proposes a novel partially covered parabolic trough photovoltaic thermal (PCPTPVT) collector to efficiently exploit solar energy. The thermodynamic model and iterative procedure are built based on the thermal resistance circuit method. Energy, exergy, exergoenvironmental, and exergoeconomic analyses are conducted to evaluate the thermodynamic, environmental, and economic performances of the novel PCPTPVT collector. Besides, multi-objective optimization of the tradeoff between cost-effectiveness and environmental friendliness is also carried out. The results show that 12.42% of the solar energy beamed on the PCPTPVT is converted into solar electricity and 61.38% of that is transformed into thermal energy for heating fluid. The electrical and thermal efficiencies of the PCPTVPT can reach 27.9% and 64.3%, respectively, and the energy and exergy efficiencies have notable improvements of 11.11% and 6.19% when the solar irradiation changes from 300 W/m2 to 1100 W/m2. The unit exergy emissions of CO2, NOX, and SO2 of the PCPTPVT under design conditions are 18.39 g/kWh, 117.8 mg/kWh, and 149.4 mg/kWh, and life cycle pollutant emission reductions reach 136.08 t, 971.92 kg, and 1125.35 kg, respectively.

Resistance circuit training combined with hypoxia stimulates bone system of older adults: A randomized trial

PurposeAging leads to gradual irreversible decline in bone mass. As adherence to pharmacological treatment is poor, hypoxia combined with strength training has been suggested for therapeutic benefit for clinical populations. The present study investigated the effects of normobaric cyclic hypoxic exposure combined with resistance circuit training on bone of older adults. MethodsHealthy older adults (n = 50) were randomly assigned to a (1) control group (CON; n = 20), who were instructed to continue with their normal daily activities, (2) a group that performed resistance training in normoxia (RTN; n = 17) and (3) a group that performed resistance training in hypoxia (RTH; n = 13). During 24 weeks, RTH group performed resistance training with elastic bands under normobaric hypoxic conditions (16.1 % FiO2). A session of both exercise groups included nine exercises of several body areas with a structure of 3 sets × 12–15 repetitions per exercise, with a 1-minute rest between sets. Bone mineral density (g·cm-2) was measured using dual-energy X-ray absorptiometry. Bone turnover markers of formation (N-terminal propeptide of type I procollagen; PINP) and resorption (C-terminal telopeptide of type I collagen; bCTX) were analysed with enzyme-linked immunosorbent assay (ELISA) microplate reader. ResultsValues of bCTX and bCTX/PINP significant decreased in RTN (bCTX: 47.79 %; p = 0.002; bCTX/PINP: 61.43 %; p = 0.007) and RTH (bCTX: 59.09 %; p = 0.001; bCTX/PINP: 62.61 %; p = 0.003) groups compared with CON group. Change in bone mineral density was not significantly different between groups. Based on clinically significant change, 23 % of the participants in the RTH group reached this value for femoral neck and trochanter bone mineral density (vs 0 % and 6 % of the RTN group, respectively). Conclusions24-Weeks of normobaric cyclic hypoxic exposure combined with resistance circuit training has potential to generate positive effects on bone in older adults.Trial registration number: NCT04281264 (date of registration: February 24, 2020).

A New Method for Triggering Lithium-Ion Cell Internal Short Circuit (ISC) While Monitoring the ISC Current

Internal short circuit (ISC) is a critical failure mechanism for lithium-ion cells that can lead to disastrous thermal runaway. Therefore, great effort has been made to understand its mechanisms by purposefully triggering ISC through various methods1, 2, such as embedding a nickel particle3 or a wax covered copper pad4 inside lithium-ion cells. While these methods have been successful in triggering ISC, none of them allows measurement of ISC current, a critical parameter that influences heat generation and risk of thermal runaway. Alternatively, Feng et al.5 reported a method of placing a resistor between two parallel-connected cells and using the resistor to externally short circuit the cells. This method could allow measurement of short circuit current, but the resistor is placed between two cells rather than between electrode layers to create different types of ISC6. Inspired by this method5 and the established ISC methods3, 4, here we report a new method that not only triggers lithium-ion cell ISC but also monitors ISC current.As shown schematically in Figure 1, the method works by inserting a pair of small nickel pads inside a lithium-ion cell. One pad is between cathode and separator. The other is between anode and separator. Then the pads are connected electronically outside the cell through insulated metal wires, a switch and a current sensor. Once the switch is closed, the anode and cathode will be shorted at the pad region to form an Anode-Cathode type ISC. The ISC current is forced to flow through the external circuit to be measured by the current sensor. The resistance of the external circuit is much lower than the resistance between nickel pads and their corresponding electrode, so heat generation is focused inside the cell at the pad region as in an ISC scenario. By adjusting dimension of the nickel pads and/or the pressure applied to the pad region, the ISC resistance can be adjusted for investigation of its effects. Furthermore, by connecting one of the pads electronically to the opposite tab, the Anode-Aluminum type ISC and the Cathode-Copper type ISC, can be created. Alternatively, these types of ISC can be created by removing part of electrode coating and placing one of the Ni pads to be in direct contact with current collector. In addition, by embedding thermocouples inside the cell7, temperature distributions can be simultaneously measured for understanding of electrochemically-thermally coupled phenomena during ISC.Figure 2 shows preliminary results obtained from a prototype lithium-ion cell using this new method. The cell has a single unit of electrodes and a nominal capacity of 0.02 Ah. Three types of ISC were created, including Anode-Cathode, Anode-Aluminum and Cathode-Copper. As expected, the Anode-Cathode type ISC had the smallest current while the Anode-Aluminum type ISC had the highest current6, which can be attributed to the high resistance of cathode and the contact resistance between nickel pad and electrode. More results and analysis will be presented. References X. Lai, C. Jin, W. Yi, X. Han, X. Feng, Y. Zheng and M. Ouyang, Energy Storage Materials, 35, 470 (2021).G. Zhang, X. Wei, X. Tang, J. Zhu, S. Chen and H. Dai, Renewable and Sustainable Energy Reviews, 141, 110790 (2021).IEEE, IEEE Std 1625-2008 (Revision of IEEE Std 1625-2004), 1 (2008).E. Darcy and M. Keyser, On-Demand Cell Internal Short Circuit Device, in Power Sources Conference 2014; 9-12 Jun. 2014; , Orlando, FL; United States (2014).X. Feng, X. He, L. Lu and M. Ouyang, Journal of The Electrochemical Society, 165, A155 (2018).S. Santhanagopalan, P. Ramadass and J. Zhang, Journal of Power Sources, 194, 550 (2009).S. Huang, Z. Du, Q. Zhou, K. Snyder, S. Liu and G. Zhang, Journal of The Electrochemical Society, 168, 090510 (2021). Figure 1

Tufted hierarchical heterostructure of In2S3/WO3 photoanodes for unbiased hydrogen evolution reaction under visible light illumination

We report the fabrication of an In2S3 tufted nanostructure on WO3 as a hierarchical heterostructure for visible-light-driven water-splitting applications. The hydrothermally grown self-assembled In2S3 tufted arrays on WO3 platelets are visible light-absorbing semiconductor photocatalysts. The structural and morphological features corroborate the unique tufted nanostructure. The In2S3/WO3 photoanode results in a fivefold increment of photocurrent density (1.01 mA/cm2) at 0.2 V vs Ag/AgCl under visible light illumination compared to the pristine WO3 photoanode. The type-II n-type In2S3/WO3 heterostructure favors the electron-hole separation and enforces the large photo potential (−0.98 V vs Ag/AgCl) under visible light illumination. The enhanced PEC activity of the In2S3/WO3 photoanode can be attributed to the reduced charge transfer resistance and higher open circuit potential. Substantial stability and photocurrent retention (77 %) are achieved for the In2S3 tuft grown on WO3 with 0.55 % of photon-to-electronic conversion efficiency.

Main Circuit Topology and Electromagnetic Interference of Electric Vehicle Bidirectional Charger

In order to improve the electromagnetic compatibility performance of electric vehicle bidirectional chargers, the authors propose a main circuit topology and electromagnetic interference of the electric vehicle bidirectional charger. The design adopts the parallel connection of silicon carbide (SiC) MOSFETs and completes the bidirectional charging system based on the cascade connection of dual active bridge (DAB) and three-phase four-wire inverter. This paper mainly analyzes the influence of parasitic inductance on the drive and power loop of the T0-247 packaged switch in actual use, and according to the operating characteristics of the system, different gate resistors are used to reduce switching losses and improve system efficiency. And, we explore on how to reduce the overshoot voltage through the RC absorption circuit, thereby reducing the conducted interference. The result shows the following: the primary side absorption circuit resistance is 470 Ω and the capacitor is 47 nf, the secondary side absorption circuit resistance is 40 Ω and the capacitance is 4.7 nf, and the circuit power is 5000 W. Under the same conditions, without adding the RC absorption circuit, the conducted interference on the AC side does not meet the standard, and the amount of disturbance is large. After adding a suitable RC absorption circuit, the conducted interference on the AC side reaches the required value. Conclusion. This research provides a systematic design scheme and optimization method for designing power electronic devices using SiC.

Systematic Interpretation of Time Effect on Negative Capacitance of Ferroelectrics Based on Electrostatics and Charge Dynamics

Negative capacitance (NC) effects in ferroelectric (FE) films have attracted intensive attention recently in terms of both polarization kinetics modeling and low-power CMOS applications. Its physical origin, however, is controversial because the experimentally observed NC effects are different from the initial concept, particularly on the frequency/voltage dependence and hysteresis. Recently, we have proposed an electrostatic model, with which the NC effect with hysteresis and voltage dependence in FE/paraelectric (PE) stacks in dc mode is explained from a viewpoint of polarization switching. Based on this, in this work, the NC effect in the dimension of time in both FE/PE and FE capacitor–resistor (FE-R) circuit is analytically formulated and experimentally studied by comprehensively considering the dynamics of polarization switching, charge communication with power supply, and charge leaking through the capacitor. Our results suggest that such NC effects only occur in a time window in both systems and a competition between FE switching and charge compensation is the key to determine the time window. Thus, a systematic understanding is accomplished to explain most of the phenomenon associated with NC effects in FEs.

Improving magnetic cooling efficiency and pulldown by varying flow profiles

Magnetic refrigeration systems are promising cooling solutions that employ the active magnetic regenerator refrigeration cycle to achieve practical temperature spans and environmental benefits. The hydraulic system that ensures a continuous flow of the heat transfer fluid through the system with a reciprocating flow in each regenerator bed is critical to the performance of the refrigeration cycle. Hence, we investigate the characteristics of the parallel flow circuit of a rotary active magnetic regenerator system, which consists of thirteen trapezoid-shaped regenerators, each filled with 295 g of gadolinium spheres. Fluid flow is controlled via electrically actuated solenoid valves (both piloted and direct-acting) connected to the regenerator hot side. By varying the percentage of opening of the control valves, different blow fractions (or fluid flow waveforms) could be investigated. The objective of the study is twofold: (i) assess whether flow imbalances of the heat transfer fluid exist in the cold-to-hot blow (cold blow) and hot-to-cold blow (hot blow) directions, and (ii) determine whether there is an optimal value of the blow fraction both to maximize the cooling performance and realize a rapid temperature pulldown. Flow resistance measurements demonstrate a symmetric flow circuit design and resistances that are similar in the cold and hot blow directions. Moreover, for the studied temperature spans of 6 K and 16 K, the best blow fraction was found to be about 41.6 %. For instance, at a 16 K span, a utilization of 0.32, and at 1.4 Hz, increasing the fluid blow fraction from 25.0 to 41.6 % enhanced the cooling capacity and second-law efficiency from 70 to 330 W and from 2.6 to 17.4 %, respectively. In turn, lower blow fractions favored a more rapid temperature pulldown. The magnetocaloric system was about 30 % faster in establishing approximately 14 K temperature span when the blow fraction was reduced from 41.6 to 30.6 %. Hence, magnetic refrigeration systems can benefit greatly from solenoid valves, which allow the system to operate either in a time-saving mode or an energy-saving mode.

Controlled Crystallinity of TiO2 Layers Grown by Atmospheric Pressure Spatial Atomic Layer Deposition and their Impact on Perovskite Solar Cell Efficiency

Atmospheric Pressure Spatial Atomic Layer Deposition (AP-SALD) is an upcoming deposition technique suitable for a variety of materials and combines the benefits of a regular atomic layer deposition with a significantly increased deposition rate at ambient conditions. In this work, amorphous and anatase TiO2 layers are fabricated by AP-SALD via systematic variation of process conditions such as temperature, reactant (H2O and O3), and posttreatment. The formed layers are characterized for their structural and optoelectronic properties and utilized as a hole-blocking layer in hybrid perovskite solar cells. It is found that TiO2 layers fabricated at elevated deposition temperatures possess strong anatase character but expose an unfavorable interface to the perovskite layer, promoting recombination and lowering the shunt resistance and open circuit voltage of the solar cells. Therefore, the interface is essential for efficient charge extraction, which can be significantly improved by controlling the process parameters.

The Effects of Eight Weeks Moderate- and High-Intensity Circuit Resistance Training on the Levels of Serum Amyloid A and Insulin Resistance in Sedentary Men

Introduction: Obesity-related inflammation has an important role in increasing the risk of various pathological conditions, including insulin resistance. In this study, the effects of 8 weeks of moderate and high-intensity circuit resistance training on the levels of serum amyloid A (SAA) and insulin resistance were investigated in sedentary men.Methods: In this study, 36 sedentary men (average BMI: 30.64 ± 3.14 kg/m2, age of 20 to 35 years old) were randomly assigned to the control (C), moderate-intensity circuit resistance training (MRT), and high-intensity circuit resistance training (HRT) groups. The training protocol was performed during eight weeks (three sessions per week). Blood samples were collected before and after eight weeks of training, and serum levels of SAA, insulin, and glucose were measured. The data were analyzed by SPSS-24 software using the analysis of covariance (ANCOVA) test with the Bonferroni post hoc test.Results: The present study’s findings indicated that SAA levels and insulin resistance significantly reduced in the HRT and MRT groups compared to the control group (P < 0.001). However, our results showed that the changes observed in SAA and insulin resistance were not significantly different between the HRT and MRT groups (P > 0.05).Conclusion: It seems that HRT has no extra effects on inflammation and insulin resistance compared to MRT; however, changes in the levels of other inflammatory mediators should be determined.

Three-Dimensional Modeling for the Internal Shorting Caused Thermal Runaway Process in 20Ah Lithium-Ion Battery

Better understanding of how internal short circuit causes thermal runaway will benefit the engineering for safer lithium-ion batteries. In this study, three-dimensional (3D) numerical simulations of a 20Ah lithium battery under internal shorting condition are performed. The effects of internal short circuit area, resistance, penetration depth, convective heat transfer coefficient and internal short circuit position, on the thermal runaway are investigated with the simulations in this work. This study demonstrates that the average cell temperature is only weakly affected by the internal short circuit area, penetration depth, and position. On the other hand, the internal short circuit resistance and the convective heat transfer coefficient have large impacts on the thermal runaway propagation in the lithium-ion battery. A high convective heat transfer coefficient can effectively suppress the thermal runaway propagation. However, such a high convective heat transfer coefficient is hard to achieve at the cell surface.

Precise and fast safety risk classification of lithium-ion batteries based on machine learning methodology

How to establish a fast and accurate model with physics implications still remains an unsolved headache for the community. Herein, we establish a battery safety risk classification modeling framework based on a machine-learning algorithm that can accurately and rapidly classify the potential safety risk level. The model can identify defective cells, cells with internal short circuits (ISCs), and cells with possible thermal runaway (TR) using a small portion of one cycle data. About 3 × 105 training samples are generated, covering a wide spectrum of State of Charge (SOC), short circuit resistance, and charging/discharging rate (C-rate)) ranges based on established electrochemo-mechanical model, serving as training and prediction datasets for the machine learning (ML) algorithm. Classifiers in the ML model demonstrates satisfactory performance and robustness. We further prove that only 5 min is needed for the model to classify the cells with over 95% accuracy with a voltage error<0.1 mV if the ISC resistance is smaller than 102Ω. This work highlights the promising future of combining physics-based numerical modeling and data-driven algorithm to provide satisfactory battery safety identification with limited data produced in a short cycling time.