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When a company's lithium-ion batteries have been found to cause numerous fires, not only the battery quality, but also the company's design, manufacturing, and testing qualifications come into question. Through a case study, this work demonstrates how a widely accessible lithium-ion battery, available in online outlets has defects, lacks sufficient protection mechanisms, and is generally at risk of being unsafe using various non-destructive methods. Company information was collected from the National Enterprise Credit Information Publicity System in China, the United States Patent and Trademark Office, and site visits. Through the investigation, it was found that the company is only a shell company with no design or manufacturing abilities. Based on the analysis, recommendations for the selection of batteries are provided, including supply chain analysis, testing, and teardown characterization.

In transportation and operation, lithium-ion batteries can be exposed to environments where the temperature exceeds 75 °C, compromising seal integrity and leading to electrolyte leakage and safety issues. Standards introduced by regulatory bodies require temperature testing, including temperature cycling tests. This study examines cylindrical battery electrolyte leakage due to temperature cycling between 25 °C and 80 °C through capacity tests, electrochemical impedance spectroscopy, computed tomography scans, and thermal analysis. Different thermal expansions among battery cap elements were identified as the cause of leakage. The thermal test parameters and requirements in the UN Manual of Tests and Criteria Section 38.3 were reviewed, revealing the 72 °C upper-temperature limit and the 24 h storage period after temperature cycling fail to effectively qualify lithium-ion batteries for real-world applications.

Cylindrical lithium-ion batteries are widely used in consumer electronics, electric vehicles, and energy storage applications. However, safety risks due to thermal runaway-induced fire and explosions have prompted the need for safety analysis methodologies. Though cylindrical batteries often incorporate safety devices, the safety of the battery also depends on its design and manufacturing processes. This study conducts a design and process failure mode and effect analysis (DFMEA and PFMEA) for the design and manufacturing of cylindrical lithium-ion batteries, with a focus on battery safety.

BackgroundEpidemiological characteristics of nonalcoholic fatty liver disease (NAFLD) in Chongqing, a west-central city of China, remain unclear. The objective of this study was to investigate the prevalence of NAFLD and the related risk factors among healthy adults for physical examination in Chongqing.MethodsA total of 110,626 subjects were enrolled in the present study. Each of the participants underwent physical examination, laboratory measurements, and abdominal ultrasonography. The chi-square test was employed to compare differences in the NAFLD prevalence, and logistic regression analysis was used to estimate the odds ratio for risk factors of NAFLD.ResultsThe prevalence of NAFLD in individuals in the population of Chongqing was 28.5%, and the prevalence in men (38.1%) was significantly higher than that in women (13.6%) (OR = 2.44; 95% CI: 2.31–2.58). NAFLD was more common in men aged 51–60 years and women over 60 years. Approximately 79.1% of the people with obesity and 52.1% of the people with central obesity had NAFLD. The prevalence of NAFLD in people with hypertension and cholelithiasis was 48.9 and 38.4%, respectively. Logistic regression showed that gender, age, body max index (BMI), central obesity, hypertension, impaired fasting glucose/diabetes mellitus (DM), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hyperuricemia (HUA), alanine transaminase (ALT), and cholelithiasis were independently associated with the presence of NAFLD.ConclusionThe prevalence of NAFLD among healthy adults in Chongqing was high. To improve the prevention and management of NAFLD, special attention should be paid to the factors associated with the presence of NAFLD, including higher BMI, higher waist circumference, higher blood glucose, hypertension, hypertriglyceridemia, hyperuricemia, cholelithiasis, and elevated ALT.

The Shack-Hartmann wavefront sensor produces incorrect wavefront measurements when some sub-spots are weak and missing. In this paper, a method is proposed to predict the centroids of these sub-spots for the Shack-Hartmann wavefront sensor based on the deep neural network. Using the centroid information of present sub-spots, the method is able to predict the absent sub-spots’ positions. The feasibility and effectiveness of this method are verified by a large number of numerical simulations. The method is applied to wavefront measurement of light with non-uniform near-field intensity. The simulation results show that the proposed method is of great help to improve the measurement accuracy and the Strehl ratio of the focal spot. For wavefronts outside of the training sample, the proposed method shows good generalization and adaptability. In addition, the experiment results demonstrate that the proposed method can predict the missing sub-spots’ centroid displacements accurately even though a large proportion of sub-spot is lost randomly.

A tip-tilt mirror (TTM) control method is designed to enhance the control bandwidth and ensure the rejection performance of the adaptive optics (AO) tip-tilt correction system. Optimized with the Smith predictor and filter, linear active disturbance rejection (LADRC) is adopted to achieve the tip-tilt correction. An AO tip-tilt correction experimental platform was built to validate the method. Experimental results show that the proposed method improves the control bandwidth of the system by at least 3.6 times compared with proportional–integral (PI) control. In addition, under the same control bandwidth condition, compared with the Smith predictor and proportional–integral (PI–Smith) control method, the system is more capable of rejecting internal and external disturbances, and its dynamic response performance is improved by more than 29%.

Abstract Objective To explore the prevalence and its associated metabolic factors of thyroid nodules (TNs) among subjects who participated in the physical examinations in Chongqing, China. Methods The participants from the Health Management Center of JinShan Hospital of Chongqing Medical University, between September 2015 and May 2020, were included in this study. All of the participants underwent thyroid ultrasonography, anthropometric measurements, and serum examinations. Differences in the TNs prevalence were compared with the chi-square test or Wilcoxon rang-sum test. Multivariable logistic regression analyses were used to estimate the metabolic factors associated with TNs and multiple thyroid nodules (MTNs). Results Of the included 121,702 participants, 41,547 had TNs, and 20,899 had MTNs, with the prevalence of 34.1 and 17.0 %, respectively. Women had a significantly higher prevalence of TNs than men (40.6 % vs. 29.8 %; χ 2 = 1517.33, P

Introduction Coronavirus disease-2019 (COVID-19) spreads worldwide. The study aimed to understand the clinical characteristics of young COVID-19 patients. Material and methods Ninety patients with severe COVID-19 infection in western Chongqing were collected from 21 January to 14 March 2020. They were divided into 4 groups based on age: youth ( 60 years). The clinical symptoms, laboratory findings, imaging findings, and treatment effects were compared among the groups. Results There were 22, 27, 19, and 22 cases in the youth, middle-aged, middle-elderly, and elderly groups, respectively. There were no significant differences with respect to gender or smoking status among the four groups. The clinical indicators of severe disease in the youth group were significantly different from the other three groups, and included the lymphocyte count (p < 0.001), C-reactive protein level (p = 0.03), interleukin-6 level (p = 0.01), chest computed tomography (CT) findings (p < 0.001), number of mild cases (p = 0.02), education level (p < 0.001), and CD4 + T lymphocyte level (p = 0.02) at the time of admission, and the pneumonia severity index (PSI) at the time of discharge (p < 0.001). The complications (p < 0.001) among the youth group were also significantly different from the other groups. Conclusions Young patients have milder clinical manifestations, which may be related to higher education level, higher awareness and higher acceptance of the prevention and control of the COVID-19 epidemic, as well as their good immune function.

18650 Lithium-ion batteries are wildly used as power sources for portable electronics because of the standardized format and economical manufacturing cost. However, commercial 18650 cells come in various designs due to the implementation of different protection devices. The current interrupt device and top vent are mandatory protection devices for all commercial 18650 Li-ion batteries. In contrast, the positive temperature coefficient thermistor, bottom vent, and protection circuit are optional protection devices that can be non-installed, installed separately, or combined in commercial 18650 batteries. Four representative commercial 18650 Li-ion batteries were disassembled and compared in terms of the similarities and differences of the protection devices. This paper overviews the working mechanism, advantages, and drawbacks of each protection device. Recommendations on battery selection and potential future trends are then provided.

Electric vehicles (EV) are considered the future of the automobile industry due to their high energy conversion efficiency and environmental friendliness. However, there are safety risks associated with Li-ion batteries, including the potential for fires and explosions. This paper reviews the challenges facing the electric vehicle market regarding the implementation of Li-ion batteries. It then presents two case studies of electric vehicles that experienced safety-related recalls which were not associated with vehicle collisions. For comparison, a history of Li-ion battery safety issues from the same brand in other applications than EV and the company’s reactions are provided. The case study and review of issues in other applications show a lack of consideration for customer safety, amplified by the additional risk used in an EV. The paper then explores corrective actions performed and analyzes how the actions will not address the root cause; additionally, contributing to a performance reduction. Recommended corrective actions for future implementation of EV batteries are provided.

Cylindrical Li-ion batteries (cells) typically have safety vents in the positive terminal to enable the release of gases that build up inside the battery and thus help reduce the effects of thermal runaway, including fire and explosion. However, the vents are not always effective, and it is critical to understand why. This paper overviews various vent designs and presents two case studies of vents in cylindrical Li-ion batteries that failed to operate properly. The first case study concerns a Sony VCT5 18650 Li-ion battery in which thermal runaway caused the cylindrical casing (can) to rupture. The second case study involves an Ampking 20700 Li-ion battery in which thermal runaway caused side-wall rupture of the casing. In both cases, the vents did not function as intended. Computed tomography (CT) scanning was used to investigate the internal structure of the battery to assess the failure mechanisms of the failed vents. These cases raise concerns about the efficiency, reliability, and safety of some current vent designs.

Aiming at the problem that it is difficult for the conventional Shack–Hartmann wavefront sensor to achieve high-precision wavefront reconstruction with low spatial sampling, a kind of Shack–Hartmann wavefront sensing technology based on four-quadrant binary phase modulation is proposed in this paper. By introducing four-quadrant binary phase modulation into each subaperture, the technology is able to use an optimization algorithm to reconstruct wavefronts with high precision. The feasibility and effectiveness of this method are verified at extreme low spatial frequency by a series of numerical simulations, which show that the proposed method can reliably reconstruct wavefronts with high accuracy with rather low spatial sampling. In addition, the experiment demonstrates that with a 2 × 2 microlens array, the four-quadrant binary phase-modulated Shack–Hartmann wavefront sensor is able to achieve approximately 54% reduction in wavefront reconstitution error over the conventional Shack–Hartmann wavefront sensor.

Li-ion battery reliability has attracted significant research attention, but few studies have incorporated in-service performance and reliability data of batteries installed within a product. This paper investigates battery drain, unexpected shutdowns, and slow performance associated with Li-ion batteries, with a focus on Apple iPhones® as a case study. The actions taken by Apple in response to these performance issues are discussed, especially from the perspective of Li-ion battery degradation. It is shown that not all battery reliability issues can be attributed to normal battery degradation; battery manufacturing defects and high C-rate applications are also shown to be contributors to battery reliability and performance issues, including those causing a low state of charge, a low state of health, and unexpected shutdowns.

This paper presents the various ways that lithium-ion batteries are being counterfeited, the problems that counterfeit batteries present, how they enter the consumer market, and the difficulties of detection. Simple external visual inspection of the battery is unreliable. As shown in the presented case study, even for the same brand batteries, their internal structures are different. The current counterfeit prevention methods focus on the manufacturing step. To reduce the risk of counterfeit batteries, device manufacturers and retail stores should characterize the batteries they receive. In addition, related authorities or organizations should set standards to enable a universal battery tracking method along the supply chain to prevent counterfeit lithium-ion batteries from entering the market.

Reindeer (Rangifer tarandus) have lengthy seasonal migrations on land and their feet possess excellent locomotor characteristics that can adapt to complex terrains. In this study, the kinematics and vertical ground reaction force (GRF) of reindeer forelimb joints (interphalangeal joint b, metacarpophalangeal joint c, and wrist joint d) under walk, trot 1, and trot 2 were measured using a motion tracking system and Footscan pressure plates. Significant differences among different locomotor activities were observed in the joint angles, but not in changes of the joint angles (αb, αc, αd) during the stance phase. Peak vertical GRF increased as locomotor speed increased. Net joint moment, power, and work at the forelimb joints were calculated via inverse dynamics. The peak joint moment and net joint power related to the vertical GRF increased as locomotor speed increased. The feet absorbed and generated more energy at the joints. During different locomotor activities, the contribution of work of the forelimbs changed with both gait and speed. In the stance phase, the metacarpophalangeal joint absorbed more energy than the other two joints while trotting and thus performed better in elastic energy storage. The joint angles changed very little (∼5°) from 0 to 75% of the stance phase, which reflected the stability of reindeer wrist joints. Compared to typical ungulates, reindeer toe joints are more stable and the stability and energy storage of forelimb joints contribute to locomotor performance in reindeer.

One of the root causes of lithium battery failure is lithium dendrite formation. Dendrites can result in internal short circuits and ultimately thermal runaway, fires, and explosions. Unfortunately, it has been difficult to study dendrites due to an inability to conduct in-situ observations. This paper presents an in-situ observation approach, consisting of an optically transparent lithium battery cell to observe dendrite growth evolution while concurrently monitoring the electrical characteristics of the cell under various current densities.

E-cigarettes have become popular as an alternative to traditional tobacco products. However, the safety of e-cigarettes is a significant issue, as there have been numerous incidents of Li-ion battery fires and explosions resulting in bodily injury and property damage. This paper presents a comprehensive review of publicly reported e-cigarette fire and explosion incidents, and then, identifies and discusses the key concerns, causes, and remedies.

In adaptive optics (AO), multiple different incident wavefronts correspond to a same far-field intensity distribution, which leads to a many-to-one mapping. To solve this problem, a single far-field deep learning adaptive optics system based on four-quadrant discrete phase modulation (FQDPM) is proposed. Our method performs FQDPM on an incident wavefront to overcome this many-to-one mapping, then convolutional neural network (CNN) is used to directly predict the wavefront. Numerical simulations indicate that the proposed method can achieve precise high-speed wavefront correction with a single far-field intensity distribution: it takes nearly 0.6ms to complete wavefront correction while the mean root mean square (RMS) of residual wavefronts is 6.3% of that of incident wavefronts, and the Strehl ratio of the far-field intensity distribution increases by 5.7 times after correction. In addition, the experiment results show that mean RMS of residual wavefronts is 6.5% of that of incident wavefronts and it takes nearly 0.5 ms to finish wavefront reconstruction, which verifies the correctness of our proposed method.

The purpose of this study is to determine a method for quickly and accurately estimating the chlorophyll content of peanut plants at different plant densities. This was explored using leaf spectral reflectance to monitor peanut chlorophyll content to detect sensitive spectral bands and the optimum spectral indicators to establish a quantitative model. Peanut plants under different plant density conditions were monitored during three consecutive growth periods; single-photon avalanche diode (SPAD) and hyperspectral data derived from the leaves under the different plant density conditions were recorded. By combining arbitrary bands, indices were constructed across the full spectral range (350−2500 nm) based on blade spectra: the normalized difference spectral index (NDSI), ratio spectral index (RSI), difference spectral index (DSI) and soil-adjusted spectral index (SASI). This enabled the best vegetation index reflecting peanut-leaf SPAD values to be screened out by quantifying correlations with chlorophyll content, and the peanut leaf SPAD estimation models established by regression analysis to be compared and analyzed. The results showed that the chlorophyll content of peanut leaves decreased when plant density was either too high or too low, and that it reached its maximum at the appropriate plant density. In addition, differences in the spectral reflectance of peanut leaves under different chlorophyll content levels were highly obvious. Without considering the influence of cell structure as chlorophyll content increased, leaf spectral reflectance in the visible (350−700 nm): near-infrared (700−1300 nm) ranges also increased. The spectral bands sensitive to chlorophyll content were mainly observed in the visible and near-infrared ranges. The study results showed that the best spectral indicators for determining peanut chlorophyll content were NDSI (R520, R528), RSI (R748, R561), DSI (R758, R602) and SASI (R753, R624). Testing of these regression models showed that coefficient of determination values based on the NDSI, RSI, DSI and SASI estimation models were all greater than 0.65, while root mean square error values were all lower than 2.04. Therefore, the regression model established according to the above spectral indicators was a valid predictor of the chlorophyll content of peanut leaves.

In the past five years, there have been numerous cases of Li-ion battery fires and explosions, resulting in property damage and bodily injuries. This paper discusses the thermal runaway mechanism and presents various thermal runaway mitigation approaches, including separators, flame retardants, and safety vents. The paper then overviews measures for extinguishing fires, and concludes with a set of recommendations for future research and development.

Introduction: Coronavirus disease-2019 (COVID-19) has spread worldwide. The study aimed to understand the clinical characteristics of young COVID-19 patients.Material and methods: Ninety patients with severe COVID-19 infection in western Chongqing were collected from 21 January to 14 March 2020. They were divided into 4 groups based on age: youth (< 39 years), middle-aged (39-48 years), middle-elderly aged (49-60 years), and elderly (> 60 years). The clinical symptoms, laboratory findings, imaging findings, and treatment effects were compared among the groups.Results: There were 22, 27, 19, and 22 cases in the youth, middle-aged, middle-elderly, and elderly groups, respectively. There were no significant differences with respect to gender or smoking status among the four groups. The clinical indicators of severe disease in the youth group were significantly different from the other three groups, and included the lymphocyte count (p < 0.001), C-reactive protein level (p = 0.03), interleukin-6 level (p = 0.01), chest computed tomography (CT) findings (p < 0.001), number of mild cases (p = 0.02), education level (p < 0.001), and CD4 + T lymphocyte level (p = 0.02) at the time of admission, and the pneumonia severity index (PSI) at the time of discharge (p < 0.001). The complications (p < 0.001) among the youth group were also significantly different from the other groups.Conclusions: Young patients have milder clinical manifestations, which may be related to higher education level, higher awareness and higher acceptance of the prevention and control of the COVID-19 epidemic, as well as their good immune function. [ABSTRACT FROM AUTHOR]

Background: Atherosclerosis has been widely accepted as an inflammatory disease of vascular, adhesion molecules play an important role in the early progression of it. The aim of the present study was to evaluate the effect of kaempferol on the inflammatory molecules such as E-selectin (E-sel), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesionmolecule-1 (VCAM-1) and monocyte chemotactic protein-1 (MCP-1) in high cholesterol induced atherosclerosis rabbit models. Methods: Thirty male New Zealand white (NZW) rabbits were randomly divided into five groups, control group, model group, fenofibrate (12mg/kg) group and kaempferol groups (150 mg/kg and 30 mg/kg). The rabbits were fed with a normal diet or a high cholesterol diet for 10 weeks. Levels of blood lipids, serum tumour-necrosis factor-alpha (TNF-α) and serum interleukin-1beta (IL-1β) were detected at the end of the sixth and tenth week. Malonaldehyde (MDA) level and superoxide dismutase (SOD) activity in serum were also determined. Lesion areas of the aorta were measured with morphometry analysis after ten weeks. Gene expression of E-sel, ICAM-1, VCAM-1 and MCP-1 in aortas was determined by RT-PCR (reverse transcription-polymerase chain reaction). Immunohistochemical staining was employed to measure protein expression of E-sel, ICAM-1, VCAM-1 and MCP-1. Results: Model rabbits fed with ten weeks of high-cholesterol diet developed significant progression of atherosclerosis. Compared with the control, levels of blood lipids, TNF-α, IL-1β and MDA increased markedly in serum of model rabbits, while SOD levels decreased. Gene and protein expressions of E-sel, ICAM-1, VCAM-1 and MCP-1 in atherosclerotic aortas increased remarkably in model group. However, comparing to the model rabbits, levels of TNF-α, IL-1β and MDA decreased significantly and serum SOD activity increased, gene and protein expressions of E-sel, ICAM-1, VCAM-1 and MCP-1 in aortas decreased significantly with the treatment of kaempferol. Conclusion: Kaempferol shows anti-atherosclerotic effect by modulating the gene and protein expression of inflammatory molecules. [ABSTRACT FROM AUTHOR]

Anti-sway performance is one of the most important factors that affect the stability of unmanned aerial vehicles (UAVs). In this paper, an anti-sway performance testing method and an evaluation formula for pesticide tanks were developed, which can facilitate the design and application of pesticide tank. The detection device mainly comprises a testing stand, a mounting and testing part, and a driving and control part. In the testing method, P (maximum pressure) measured by a barometer and t (fluctuation recovery time) measured by a high-speed camera were used as evaluation indexes. With the aim to determine the optimal position of the pressure detection device and the optimal fill ratio, four representative pesticide tanks were involved in this study. The results showed that the optimal position of the pressure detection device was at the middle position on the tank wall, halfway up from the bottom, and the optimal fill ratio was 0.8. Using P and t as evaluation indexes, a comprehensive evaluation formula was developed based on these tests: S=0.7Pi +0.3ti. Anti-sway performance of pesticide tanks was evaluated by a comprehensive score. A disk pesticide tank with a baffle was determined to be the best among the four types of pesticide tanks, showing a score of 1. The scores of the other three pesticide tanks were 0.5, 0.428 and 0.612, respectively. These results indicated that the baffle structure in the pesticide tank and the radian design of the tank wall can effectively improve the anti-sway performance of a pesticide tank. The proposed detection device and test method are simpler and more intuitive compared to other approaches in evaluating the anti-sway performance of pesticide tanks in spraying UAVs, and they can be used as a reference to guide the design of pesticide tanks and the stability evaluation of spraying UAVs. [ABSTRACT FROM AUTHOR]