Numerical and Experimental Evaluation of a Battery Cell under Impact Load

Impact damage is one of the most critical scenarios for the lithium-ion battery pack of an electrical vehicle, as it involves mechanical abusive loads with serious consequences on electrical and thermal stability. The development of a numerical model for an explicit dynamic simulation of a Li-ion battery pack under impact implies a significant computational effort if detailed models of a single battery cell are employed. The present paper presents a homogenized finite element model of a battery cell, validated by experimental tests of individual materials and an impact test of an entire cell. The macro model is composed of shell elements representing outside casing and elements with a homogenized and isotropic material for the jelly roll. The displacements and deformed shape of the numerical model of the battery cell were compared with those measured on real test specimens; full-field optical scanning was employed to reconstruct the 3D shape of the deformed battery. The overall deformation of the simulation and experimental results are comparable with a deviation of the maximum intrusion of 14.8% for impact direction and 19.5% for the perpendicular direction considering the cumulative effects of simplifying hypotheses of the numerical model and experimental side effects. The results are a starting point for future analyses of a battery pack and its protection systems under impact. The model presented in this paper, considering the low computing power needed for calculation and acceptable mesh size for crash, should be able to be used in bigger resources consuming crash simulation models. In this way, the cells’ deformation and behavior can be tracked more easily for safety management and diagnosis of the crashworthiness of the packs or car batteries

Numerical and Experimental Evaluation of a Battery Cell under Impact Load

Impact damage is one of the most critical scenarios for the lithium-ion battery pack of an electrical vehicle, as it involves mechanical abusive loads with serious consequences on electrical and thermal stability. The development of a numerical model for an explicit dynamic simulation of a Li-ion battery pack under impact implies a significant computational effort if detailed models of a single battery cell are employed. The present paper presents a homogenized finite element model of a battery cell, validated by experimental tests of individual materials and an impact test of an entire cell. The macro model is composed of shell elements representing outside casing and elements with a homogenized and isotropic material for the jelly roll. The displacements and deformed shape of the numerical model of the battery cell were compared with those measured on real test specimens; full-field optical scanning was employed to reconstruct the 3D shape of the deformed battery. The overall deformation of the simulation and experimental results are comparable with a deviation of the maximum intrusion of 14.8% for impact direction and 19.5% for the perpendicular direction considering the cumulative effects of simplifying hypotheses of the numerical model and experimental side effects. The results are a starting point for future analyses of a battery pack and its protection systems under impact. The model presented in this paper, considering the low computing power needed for calculation and acceptable mesh size for crash, should be able to be used in bigger resources consuming crash simulation models. In this way, the cells’ deformation and behavior can be tracked more easily for safety management and diagnosis of the crashworthiness of the packs or car batteries

Updated Understanding of Cancer as a Metabolic and Telomere-Driven Disease, and Proposal for Complex Personalized Treatment, a Hypothesis

In this review, we propose a holistic approach to understanding cancer as a metabolic disease. Our search for relevant studies in medical databases concludes that cancer cells do not evolve directly from normal healthy cells. We hypothesize that aberrant DNA damage accumulates over time—avoiding the natural DNA controls that otherwise repair or replace the rapidly replicating cells. DNA damage starts to accumulate in non-replicating cells, leading to senescence and aging. DNA damage is linked with genetic and epigenetic factors, but the development of cancer is favored by telomerase activity. Evidence indicates that telomere length is affected by chronic inflammations, alterations of mitochondrial DNA, and various environmental factors. Emotional stress also influences telomere length. Chronic inflammation can cause oxidative DNA damage. Oxidative stress, in turn, can trigger mitochondrial changes, which ultimately alter nuclear gene expression. This vicious cycle has led several scientists to view cancer as a metabolic disease. We have proposed complex personalized treatments that seek to correct multiple changes simultaneously using a psychological approach to reduce chronic stress, immune checkpoint therapy with reduced doses of chemo and radiotherapy, minimal surgical intervention, if any, and mitochondrial metabolic reprogramming protocols supplemented by intermittent fasting and personalized dietary plans without interfering with the other therapies

The morphofunctional pattern of neuronal biogenic amines in postpartum involution period - in vivo study

Postpartum uterine diseases are associated with significant imbalance in the levels of biogenic amines (BAs) in rat uterus. Mast cells (MCs) are the main suppliers of BAs such as serotonin, catecholamines, and histamine in uterus. There is limited evidence of the BA-positive elements involved in the physiological regulation of uterus during postpartum involution. The aim of present study is to determine the concentration and distribution of biogenic amines (BAs) such as histamine, serotonin, and catecholamines in the uterine endometrium, myometrium, and peritoneal fluid (PF) during the postpartum uterine involution. A total of 110 nulliparous outbred female nonpregnant Wistar rats of mature age were divided into eleven groups (n=10 per group) according to days of postpartum involution. Tissue specimens of uterine segments, PF were prepared. Serotonin, catecholamines, and histamine concentrations were examined by fluorescence-histochemical techniques. The fluorescence of the BA-positive elements was detected and analyzed by microspectrofluorimetry. Results were analyzed using the KruskalWallis chi-squared test and pairwise Mann-WhitneyWilcoxon tests with "Benjamini-Hochberg correction" in R 3.6.3. Mast cells in uterine segments, PF exhibited characteristic yellowish-green fluorescence. The highest MCs number was reported in corpus uteri on the 15th day of postpartum involution. Serotonin, catecholamines, and histamine levels were significantly higher in BA-positive elements in the initial days. BA content was dynamic and relies on the time elapsed after parturition. There was statistically significant difference in the levels of BAs in the cornu and cervix uteri. A single morphofunctional complex of BA supply was noticed in the reproductive system of the rats. The coupled interactions of intra- and extra-organic BA-positive elements was associated with anabolic/catabolic equilibrium in uterus through the metabolism of serotonin, catecholamines, and histamine during postpartum involution

Health science community will miss this bright and uniting star : in memory of Professor Gjumrakch Aliev, M.D, Ph.D

No abstract availablehttp://www.mdpi.com/journal/cancerspm2021Physiolog