Optimized Nail for Penetration Test on Lithium-Ion Cells and Its Utilization for the Validation of a Multilayer Electro-Thermal Model

Nail penetration is one of the most critical scenarios for a lithium-ion cell: it involves the superposition of electrical, thermal and mechanical abusive loads. When an electrically conductive nail is introduced into the active layers of a lithium-ion cell, an electric short circuit takes place between the conductive components (electrodes and current collectors). Hence, for this load case, electro-thermal modeling must be performed considering each and every layer of the cell in order to predict the electric quantities and the cell temperature (with numerical models). When standard conic nails are used, as is typical for this class of tests, the electrical contact between conductive components and the nail itself suffers of poor reproducibility mainly due to the separator that interposes between the electrically conductive components. This phenomenon makes it difficult to validate electro-thermal models, since the electrical contact between nail and lithium-ion cell parts cannot be safely determined. In this work, an alternative nail with an optimized ratio between the external surface and volume is presented to overcome this issue. To demonstrate the effectiveness of the designed nail, five tests (with the same conditions) were conducted on five commercial lithium-ion pouch cells, monitoring the tabs voltage and surface temperature. In all tests, thermal runaway was reached within 30 s and the tabs voltage showed comparable behavior, indicating that the short circuit values for all five repetitions were similar. The investigation included the implementation of a detailed layers model to demonstrate how the validation of such model would be possible with the novel data

Explaining differences in efficiency. A meta-study on local government literature

This paper reviews the literature on local government efficiency by meta-reviewing 360 observations retrieved from 54 papers published from 1993 to 2016. The meta-regression is based on a random effect model estimated with the 2-step Random Effects Maximum Likelihood (REML) technique proposed by Gallet and Doucouliagos (2014). Results indicate that the study design matters when estimating a frontier in local government. We find that studies focusing on technical efficiency provide higher efficiency scores than works evaluating cost efficiency. The same applies when using panel data instead of cross-section data. Interestingly, studies that use the Free Disposal Hull (FDH) approach yield, on average, higher efficiency scores than papers employing the Data Envelopment Analysis (DEA) method, thereby suggesting that in this literature the convexity hypothesis of the production set is a matter. Finally, the efficiency of local government increases with the level of development of the analysed countries and is positively related to the national integrity of the legal system. The opposite holds when considering the corruption

Explaining differences in efficiency. A meta-study on local government literature

This paper reviews the literature on local government efficiency by meta-reviewing 360 observations retrieved from 54 papers published from 1993 to 2016. The meta-regression is based on a random effect model estimated with the 2-step Random Effects Maximum Likelihood (REML) technique proposed by Gallet and Doucouliagos (2014). Results indicate that the study design matters when estimating a frontier in local government. We find that studies focusing on technical efficiency provide higher efficiency scores than works evaluating cost efficiency. The same applies when using panel data instead of cross-section data. Interestingly, studies that use the Free Disposal Hull (FDH) approach yield, on average, higher efficiency scores than papers employing the Data Envelopment Analysis (DEA) method, thereby suggesting that in this literature the convexity hypothesis of the production set is a matter. Finally, the efficiency of local government increases with the level of development of the analysed countries and is positively related to the national integrity of the legal system. The opposite holds when considering the corruption

Silica-based mesoporous materials as drug delivery system for methotrexate release.

Antineoplastic methotrexate has been loaded through different soaking procedures on silica-based mesoporous materials and, successively, released mimicking an oral administration. The materials were prepared using a self-assembly mechanism in the presence of cationic surfactants with alkyl chain of 16, 12, and 10 carbon atoms in the synthesis mixture to obtain different pore diameter in the porous structure. Mesoporous materials were prepared as pure silica sample and in the presence of Al(OH)(3) in the synthesis mixture. Only alumina-silica samples were able to load methotrexate. The amounts of drug loaded and the in vitro release kinetics are a function of the pore size of the materials

Serum-Activated K and Cl Currents Underlay U87-MG Glioblastoma Cell Migration

Glioblastoma cells in vivo are exposed to a variety of promigratory signals, including undefined serum components that infiltrate into high grade gliomas as result of blood-brain barrier breakdown. Glioblastoma cell migration has been further shown to depend heavily on ion channels activity. We have then investigated the modulatory effects of fetal calf serum (FCS) on ion channels, and their involvement in U87-MG cells migration. Using the perforated patch-clamp technique we have found that, in a subpopulation of cells (42%), FCS induced: (1) an oscillatory activity of TRAM-34 sensitive, intermediate-conductance calcium-activated K (IK(Ca)) channels, mediated by calcium oscillations previously shown to be induced by FCS in this cell line; (2) a stable activation of a DIDS- and NPPB-sensitive Cl current displaying an outward rectifying instantaneous current-voltage relationship and a slow, voltage-dependent inactivation. By contrast, in another subpopulation of cells (32%) FCS induced a single, transient IK(Ca) current activation, always accompanied by a stable activation of the Cl current. The remaining cells did not respond to FCS. In order to understand whether the FCS-induced ion channel activities are instrumental to promoting cell migration, we tested the effects of TRAM-34 and DIDS on the FCS-induced U87-MG cell migration using transwell migration assays. We found that these inhibitors were able to markedly reduce U87-MG cell migration in the presence of FCS, and that their co-application resulted in an almost complete arrest of migration. It is concluded that the modulation of K and Cl ion fluxes is essential for the FCS-induced glioblastoma cell migration. J. Cell. Physiol. 226: 1926-1933, 2011. (C) 2010 Wiley-Liss, Inc

Power Moderates the Effects of Social Dominance Orientation on Punishment: An Experimental Analysis

In this study, it was hypothesized that experimentally manipulated levels of power would moderate the association of dispositional social dominance orientation (SDO) with preferences for harsh punishment. In particular, we expected to detect a stronger effect for dispositional SDO in the low-power condition, relying on the notion that low power enhances sensitivity to threats to the status quo, and that high SDO individuals are particularly motivated to enforce hierarchy-enhancing measures as punishment. SDO scores were measured two months prior to the experiment, and then immediately after the experimental session. As expected, preexperimental SDO interacted with the power manipulation. We found stronger preexperimental SDO effects on punishment among low-power participants. We also anticipated and found that individuals high in SDO increased further their postexperimental SDO scores if assigned to a high-power condition. The discussion focuses on the importance of SDO effects among low-status groups and on how situational roles shape dispositional self-descriptions

Efficacy of Intracolonic Administration of Low-Molecular-Weight Heparin CB-01-05, Compared to Other Low-Molecular-Weight Heparins and Unfractionated Heparin, in Experimentally Induced Colitis in Rat

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Performance of Nickel-Iron nanostructured electrodes at different temperatures

In recent years, the whole world has been trying to reduce CO2 emissions through the global decarbonization of energy processes. In this view, the interest towards green hydrogen has drastically increased. One way to produce green hydrogen is by water electrolysis using only electricity from renewable sources. The storage of renewable solar or wind electricity is a major challenge to build a sustainable future energy system. The electrochemical production of hydrogen, through electrolysers, is a viable strategy to take advantage of the surplus electricity coming from renewable energy sources. Its production is pollution-free but is not economically viable. The development of more efficient electrolysers with low-cost electrode materials plays a key role. Catalysts must have such as good electrocatalytic properties, high conductivity, high availability, low cost, and good chemical stability. Nowadays, research is focused on improving the Alkaline Water Electrolysis (AE) to reduce the cost of electrode production. In alkaline environment it was demonstrated that, transition metals, and in particular Nickel or nickel based alloy nanostructured electrodes, have good and stable performances. Furthermore, industrial alkaline electrolysers work at temperatures between 40 and 90°C. Therefore, electrodes must be mechanically and chemically stable at these temperatures. An approach to improve AE performance consists on the fabbrication of nanostructured electrodes because they are characterized by high electrocatalytic activity due to the very high surface area. Starting from the results obtained in a previous work, the nanostructured alloy of NiFe was tested both as cathode and anode at three different temperatures (25 °C, 40 °C, 60 °C). Nanostructured electrodes were obtained through a simple and cheap method, template electrosynthesis, using a polycarbonate membrane as a template. NiFe electrodes morphology was studied by scanning electrode microscopy (SEM) and their composition was evaluated by energy diffraction spectroscopy (EDS) analyses. Later, the electrodes were characterized using various electrochemical techniques: Cyclic Voltammetry (CV), Quasi Steady State Polarization (QSSP) and Galvanostatic Step. To evaluate the mid-term behavior of the electrodes, especially at high temperatures, a constant current density was applied for 6 hours. In particular, -50 mA cm-2 for Hydrogen Evolution Reaction (HER) and 50 mA cm-2 for Oxygen Evolution Reaction (OER). All the tests were performed in 30% w/w KOH aqueous solution. Temperature increase plays a key role in increasing the efficiency of both anode and cathode reactions. As expected, the best result was obtained at 60 °C. Acknowledgments This research was funded by MUR, CNMS Centro Nazionale per la Mobilità sostenibile grant number CN0000002

Green and Integrated Wearable Electrochemical Sensor for Chloride Detection in Sweat

Wearable sensors for sweat biomarkers can provide facile analyte capability and monitoring for several diseases. In this work, a green wearable sensor for sweat absorption and chloride sensing is presented. In order to produce a sustainable device, polylactic acid (PLA) was used for both the substrate and the sweat absorption pad fabrication. The sensor material for chloride detection consisted of silver-based reference, working, and counter electrodes obtained from upcycled compact discs. The PLA substrates were prepared by thermal bonding of PLA sheets obtained via a flat die extruder, prototyped in single functional layers via CO2 laser cutting, and bonded via hot-press. The effect of cold plasma treatment on the transparency and bonding strength of PLA sheets was investigated. The PLA membrane, to act as a sweat absorption pad, was directly deposited onto the membrane holder layer by means of an electrolyte-assisted electrospinning technique. The membrane adhesion capacity was investigated by indentation tests in both dry and wet modes. The integrated device made of PLA and silver-based electrodes was used to quantify chloride ions. The calibration tests revealed that the proposed sensor platform could quantify chloride ions in a sensitive and reproducible way. The chloride ions were also quantified in a real sweat sample collected from a healthy volunteer. Therefore, we demonstrated the feasibility of a green and integrated sweat sensor that can be applied directly on human skin to quantify chloride ions