•A systematic approach for analyzing safety barriers in a battery pack.•Investigation on the battery degradation and barriers against cascading failures.•Integration of thermal propagation, thermal ...simulations, degradation, and reliability analysis.
Lithium-ion batteries have been widely employed as the principal power source in electric vehicles and other storage systems. However, some critical issues in a battery pack still exist, such as thermal failures on initial cells that impact the temperatures of the surrounding cells. Such cascading failures may significantly affect battery performance and safety. Thermal barriers, as one kind of safety barrier, are therefore installed to prevent failure propagations. This paper focuses on the situation when the temperature of battery cell increases, but the battery pack still can be used in a degradation mode since the barriers are against cascading failures. An approach is proposed to analyze how the deployment and performance of thermal barriers in a battery pack determine their capabilities against cascading failures. The approach includes thermal propagation models associated with the simulations, degradation models, reliability analysis, and barrier analysis. Its application is illustrated with a practical case study. The battery reliabilities are sensitive to many factors of the barriers, such as temperature differences, failed cells, and performance coefficient. The barriers between parallel cells are found to be more effective in mitigating failure propagation. Such findings can be beneficial for barrier optimization and reliability improvement of battery packs.
1,1'-Azobis(tetrazole) (N sub(10)) as a potential eco-friendly material, has the highest nitrogen content among the azo-stabilized poly-nitrogen compounds. The detailed potential energy surface of N ...sub(10) was thoroughly investigated using M06-2X, MP2 and CCSD(T) calculations, and the main decomposition pathways were calculated by canonical transition state theory modeling. Amongst all the channels studied, ring opening of the N sub(10) compound, followed by N sub(2) elimination to form the linear molecule Im8 is predicted to be the primary decomposition channel. The linear species formed (Im8) is characterized by a successive four-nitrogen atom chain stabilized by two terminal HNC groups. Its thorough decomposition reaction is strongly exothermic with a barrier height of 67.5 kcal mol super(-1). TST calculations were performed to probe the influence of temperature on the rate coefficients at 1 atm. Based on the thermal decomposition mechanism of N sub(10), the novel species N sub(12) and N sub(14) were explored. These longer nitrogen chain compounds having higher nitrogen content than N sub(10) are strongly expected to improve performance of high energy density materials. It is found that the predicted structures could exist at room temperature by comparison of their energetic barriers with the corresponding primary N sub(2)-elimination reaction of N sub(10).
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Psychoanalysis, History, and Radical Ethics: Learning to Hear explores the importance of listening, being able to speak, and those who are silenced, from a psychoanalytic perspective. In ...particular, it focuses on those voices silenced either collectively or individually by trauma, culture, discrimination and persecution, and even by the history of psychoanalysis. Drawing on lessons from philosophy and history as well as clinical vignettes, this book provides a comprehensive guide to understanding the role of trauma in creating silence, and the importance for psychoanalysts of learning to hear those silenced voices.
This work reports a <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga 2 O 3 double-barrier Schottky barrier diode (DBSBD) with both low turn-on voltage and low reverse ...leakage current by using Ni and PtO x as the anode electrode. The barrier height of PtO x -based diode can be effectively modulated from 1.26 to 1.62 eV by adjusting oxygen pressure during sputtering processes. Combining the maximum work function of PtO x electrode with the optimization of the electrode ratio of Ni and PtO x , the DBSBD with an electrode diameter ratio of <inline-formula> <tex-math notation="LaTeX">\text{D}_{\text {Ni}} /\text{D}_{\text {PtOx}}= {75}/{150} \mu \text{m} </tex-math></inline-formula> not only exhibits a high forward current of 470.9 A/cm 2 (at 3.5 V), a low on-resistance of 4.1 <inline-formula> <tex-math notation="LaTeX">\text{m}\Omega ~\cdot </tex-math></inline-formula>cm 2 and a low turn-on voltage of 1.13 V, but also possesses a relatively low reverse leakage current of <inline-formula> <tex-math notation="LaTeX">{1.2}\times {10}^{-{7}} </tex-math></inline-formula> A/cm 2 (at −100 V), which is more than one order of magnitude lower than that of the Ni-SBD. Silvaco TCAD simulation reveals that such optimization can be attributed to the suppression of edge leakage current due to the double-barrier contact. Therefore, the strategy of double-barrier design can balance the forward and reverse characteristics in SBD, providing a new device structure for advanced power electronics.
Leakage current of 1200-V 4H-SiC Schottky barrier diodes (SBDs) with different structures increased by various degrees after heavy-ion exposure. By taking <inline-formula> <tex-math ...notation="LaTeX">{I} </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">{V} </tex-math></inline-formula> measurements in a range of 298 to 448 K, the voltage dependence of saturation current (<inline-formula> <tex-math notation="LaTeX">I_{0} </tex-math></inline-formula>), barrier height (<inline-formula> <tex-math notation="LaTeX">\phi _{B0} </tex-math></inline-formula>), and ideality factor (<inline-formula> <tex-math notation="LaTeX">n </tex-math></inline-formula>) were obtained. The dependence of these parameters with temperature illustrates the Gaussian distribution of barrier height. The inhomogeneity of the Schottky barrier height (SBH) distribution was successfully described using a modified thermionic emission (TE) model with Gaussian distribution, and the average barrier height (<inline-formula> <tex-math notation="LaTeX">\bar {\phi }_{B0} </tex-math></inline-formula>) was gained. The results show that the barrier height distribution of all SBDs remain unchanged after the irradiation which means heavy-ion exposure did not affect the Schottky barrier.
Even though much attention has been given to barriers related to implementing circular business models, so far, no studies have focused on how the barriers differ between business models. Ignoring ...the possibility of such differences could lead to unjustified generalizations about the barriers to implementing circular business models (CBMs). We identified barriers to implementation and compared them for different CBMs by analyzing 43 case studies of CBMs, based on in-depth interviews with 31 Dutch firms. Barriers were analyzed for the following CBMs: circular supplies, resource recovery, product life extension, and the product-as-a-service model. The barriers identified were classified into two broad categories: internal problems related to the firm itself and external barriers related to the firm's environment. This study shows that key challenges were related to the firm's external environment, and that the barriers differed between the four business models studied. Whereas most internal barriers encountered by the product-as-a-service model were to do with organization (for instance, of lease models), the other models reported these barriers less frequently. External supply chain issues were challenging in the resource recovery, product life extension, and circular supplies models, mainly because of great dependence on third parties for the input of discarded products and waste materials. We investigated the strategies firms used to overcome these barriers. From our findings we conclude that to stimulate the development of circular businesses, firms and policy makers should focus on bespoke solutions and strategies for different types of CBMs.
•This study explores barriers to implementation for different circular business models.•Our findings illustrate that barriers differ between circular business models.•All the circular business models faced formidable barriers related to the external firm environment.•Different types of barriers per business model point to the need for bespoke solutions.
The practical management of heart failure remains a challenge. Not only are heart failure patients expected to adhere to a complicated pharmacological regimen, they are also asked to follow salt and ...fluid restriction, and to cope with various procedures and devices. Furthermore, physical training, whose benefits have been demonstrated, is highly recommended by the recent guidelines issued by the European Society of Cardiology, but it is still severely underutilized in this particular patient population. This position paper addresses the problem of non‐adherence, currently recognized as a main obstacle to a wide implementation of physical training. Since the management of chronic heart failure and, even more, of training programmes is a multidisciplinary effort, the current manuscript intends to reach cardiologists, nurses, physiotherapists, as well as psychologists working in the field.
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Ocular drug delivery is still a challenge for researchers in the field of pharmaceutical technology due to anatomical and physiological eye characteristics. The tissue barriers (such ...as cornea, conjunctiva, blood aqueous barrier, and blood–retinal barrier) limit the access of drugs to their targets. Taking into account the short retention time in the precorneal area of classical ocular dosage forms (e.g. solutions, suspensions or ointments) which are rapidly eliminated by tears and eyelid movement, only less than five percent of the administered drug attains intraocular structures. With the aim to overcome ocular barriers, drug delivery systems, able to increase ocular bioavailability reducing side effects, are recognized as promising alternative. In this review, the main barriers and strategies to increase drug transport in ocular delivery are comprehensively discussed, highlighting the factors involved in ocular transport of SLN and NLC.
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