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Lithium Tetrafluoroborate-Based Ester Electrolyte Formulations to Improve the Operating Temperature Range in NCM 622 || Graphite Li-Ion Batteries
No full textThe use of alternative lithium salts, lithium tetrafluoroborate (LiBF4), lithium difluoro(oxalato)borate, and lithium hexafluorophosphate (LiPF6), in the ester/fluoroethylene carbonate electrolyte results in improved low-temperature performance at -20 °C compared to LiPF6 in a carbonate-based electrolyte, but the room-temperature performance of the ester-based formulation has significant capacity fade due to the instability of the solid electrolyte interphase (SEI). Incorporation of electrolyte additives, lithium bis(oxalato)borate, lithium difluorophosphate, and lithium bis(trimethylsilyl) phosphate (LiTMSP), into lithium tetrafluoroborate (LiBF4) ester-based electrolytes (methyl acetate/fluoroethylene carbonate-MA/FEC) has been investigated in graphite//LiNi0.6Co0.2Mn0.2O2 cells to improve room-temperature cycling stability without diminishing low-temperature rate performance. The LiBF4-based ester electrolyte containing 1% LiTMSP delivers the highest reversible capacity at low temperature (-20 °C), while the room-temperature performance is significantly improved compared to that of the base ester-based electrolyte (LiBF4-MA) and almost comparable to that of the standard carbonate-based electrolyte. The improved electrochemical performance for 1% LiTMSP at -20 °C is due to the lower charge transfer resistance as supported by electrochemical impedance spectroscopy, and improved room-temperature performance can be ascribed to the generation of a stable phosphate-rich SEI on the graphite surface as revealed by X-ray photoelectron spectroscopy
Formation of undulating seafloor bedforms during the Minoan eruption and their implications for eruption dynamics and slope stability at Santorini
Get PDFThe Minoan eruption of Santorini is one of the largest Holocene volcanic events and produced several cubic kilometers of pyroclastic flows emplaced on the submerged flanks of the volcano. Marine geophysical surveys reveal a multitude of undulating seafloor bedforms (USBs) around Santorini. While similar structures are known from other volcanoes worldwide, Santorini offers the unique opportunity to relate USB formation with volcanic processes during one of the best-studied volcanic eruptions worldwide. In this study, we combine high-resolution seismic reflection data with multibeam echosounder bathymetry to reveal the internal architecture of USBs around Santorini and to relate their morphological characteristics to formational processes. The USBs around Santorini were formed during the Minoan eruption and represent the seafloor expression of mass transport deposits. Three types of deposits differ in composition or origin. (1) Depositional USBs, which can only be found to the north of the island, where Minoan eruption ignimbrites reach their maximum thickness and the undulating topography is the result of thrusting within the deposit. (2) USBs related to slope failures of volcaniclastics from the entire Thera Pyroclastic Formation, which can be found east, south, and west of the island. (3) USBs associated with deep-seated deformation, which occurs on the southwestern flank along an area affected by rift tectonics and extends to a depth of more than 200 m below the seafloor. In cases (2) and (3), the USBs are formed upslope by block rotation and downslope by thrusting. Our study indicates that these processes may have contributed to the generation of the devastating Minoan tsunami. Since Santorini is located in one of the most tectonically active regions in the Mediterranean, capable of producing earthquakes with magnitude M7+, our study has important implications for hazard assessment. A strong earthquake located close to the island may have the potential to reactivate slope instabilities posing a previously undetected but potentially significant tsunami hazard
Improving Society and the Planet: Sustainability and Fashion Post-Pandemic
Get PDFThe COVID-19 pandemic has exposed the vulnerability of our ecosystem and demonstrated a crucial need to address sustainability across the fashion supply chain, including the end-use consumer. As consumers become more conscious and demand sustainable fashion, the question of whether the pandemic has shaped such behaviors for long-term transitions remains unanswered. This qualitative study aimed to understand whether the COVID-19 pandemic has created a societal shift in individual attitudes toward sustainable fashion, whether it can help to motivate long-term sustainable consumption practices, and whether positive psychology plays a role in this context. With online survey data collected from 154 US consumers, summative content analysis and thematic analysis results revealed that as consumers continued to be puzzled by what constitutes sustainability, their pro-sustainability attitudes and behaviors did not evolve as claimed by prior literature. However, not only positive emotions associated with care and concern motivated consumers’ pro-sustainability, but indeed post-purchase positive feelings of contentment and altruism were revealed, affirming the need for marketing messages to incorporate positive psychology perspectives to motivate long-term sustainable fashion consumption practices
Nursing students’ attitudes towards the use of digital technology in the healthcare of older adults- a cross-sectional study in Norway and Sweden
Get PDFBackground: Implementation of digital technology has been suggested as a potential solution to future healthcare challenges. Healthcare personnel’s attitudes are important in the acceptance and implementation of digital technologies.
Aim: The aims of this study were to (1) translate and validate two different questionnaires to Norwegian and Swedish respectively, and then (2) use these to examine nursing students’ attitudes towards digital technology in healthcare, as well as their attitudes towards older adults’ abilities to use digital technology.
Design: Cross-sectional.
Methods: A web-based questionnaire was distributed in first year nursing students in a Norwegian and a Swedish university college, respectively. The questionnaire consisted of the short form of the ‘Information Technology Attitude Scales for Health (ITASH)’ and the ‘Attitudes Towards Older Adults Using Digital technology (ATOAUT-11)’ questionnaire. The questionnaires were translated and validated in both countries. Frequencies, Student’s t-test, and one-way ANOVA were used to analyze the data.
Results: In total 236 students responded to the questionnaire in the period September 2022 to April 2023. Students mainly reported positive attitudes towards digital technology use in general. They most agreed with the items ‘Using digital technology devices makes my communication with other health professionals faster’, ‘The sort of information I can get from the digital technology devices helps me give better care to patient’, and ‘Digital technology skills are becoming more and more necessary for healthcare professionals’. However, they reported more negative attitudes towards older adults using digital technology. They most agreed with the items ‘One needs a lot of patience to explain to an older adult how to use digital technologies’, ‘It’s hard to explain to older adults how to use digital technology’, ‘Using digital technology is harder for most older adults’, and ‘Most older adults fear using digital technology because they fear of being scammed or cheated’.
Conclusion: The ITASH and the ATOAUT-11 is appropriate for use in a Norwegian and Swedish setting. Even if nursing students are positive to digital technology in healthcare in general, they are sceptical to older adults using digital technology. This may impact on their attitudes to using digital technology in the healthcare of older adults. These aspects need emphasis when revising nursing education curricula focusing on developing technological competencies in nursing, and gaining knowledge regarding older adults’ use of digital technology
Test Chamber for Dust-Blanketed Surface Temperature Testing
Get PDFTeam 8, or Dust X8 was tasked by FM Approvals with the challenge of designing a test system with the capabilities to cover test samples ranging in size from 75-320 mm in 200 mm of dust (diatomaceous earth) on all sides of the specimen. This system was to be designed to support “dust blanketed surface temperature” testing and installed in the FM Approvals Testing facility in Norwood, MA where tests relevant to the certification of equipment for use in class II explosive atmospheres is conducted. Ideally, this test system needed to provide ease of loading and unloading, a simple pluggable interface to connect samples in the chamber with the test equipment in the control room, capability to cover and uncover test samples with diatomaceous earth from outside the chamber to minimize contact with the dust, and to be in alignment with standards IEC 60079-0 and IEC 60079-31, which determine the worst case surface temperature of the equipment while under power and blanketed on all sides by diatomaceous earth at a thickness of at least 200 mm. Team 8 studied the scope of temperature testing and what specifications such a chamber would require. From this literature search, the team advanced to a patent search and used this information to begin brainstorming design specifications and concepts. Using decision analysis tools, the team was able to filter multiple designs, material choices, and the rank importance of the customer requirements. The result of this process proved the team\u27s final design concept to be a cost-effective test chamber that supports “dust blanketed surface temperature” testing and meets the customer\u27s requirements. It was also found through competitor analyzes that such a product is not yet commercially available
Raytheon Handling Fixture to Facilitate Cabinet Assembly Test
Get PDFRaytheon Technologies Missile Defense presented team 6 with designing a fixture that prevents and supports a cabinet. This fixture also needs to be able to be transported via forklift from a set location to another set location. The process used to approach this problem is as follows. The team initially created a problem definition based on the information provided by Raytheon. Then the team calculated the force needed to counter the tipping of the cabinet. Finally, the team created multiple designs with customer requirements in mind, and modeled the cabinet and fixture in a CAD program. Once completed, the team presented a 3-D modeled fixture as well as the calculations involved with the cabinet attached to the fixture. The results of the calculation showed that the team\u27s design is a valid solution to the problem presented by Raytheon Technologies Missile Defense
eVTOL Magnetic Seal Desigjn
Get PDFSeal team 21 was tasked by Magseal to design a magnetic bearing seal for the emerging eVTOL (Electric Vertical Takeoff Landing) market. Located in Warren, RI, Magseal is one of two unique manufactures of magnetic seals for the aerospace industry. Contrary to Magseals competitor, Magseal specializes specifically in smaller to medium sized seals catered to the aerospace and aeronautics industry. Magseal specializes in magnetic seals that are engineered to outperform in conditions that present high speeds, vibrations, temperatures, and pressures. Which are all common conditions for the applications that their seals are used for. Magseals can be found in gearboxes, rotors, transmissions, and even fuel pumps. Furthermore, Magseals can be found wherever a bearing with fluid is present. In this application, Magseal products offer an advantage over traditional fluid seals for both lifespan as well as effectiveness. The goal for Seal Team 21 was to design a seal specifically for electric vehicles at a lower cost with minimal disadvantages. In a sense, the team was tasked with designing an “Under-Engineered” seal for the electric vehicle application. This is because electric vehicles have a much less harsh environment in which the seal operates. Most electric vehicles have significantly less vibration, speed, power, and heat for the seal to be able to withstand. The process included a literature search, patent search, and 120 different concepts. The final concept was chosen using Pugh’s analysis and a QFD analysis. Many different dimensions, materials, and design features were considered optimize the design. Further calculations were used to determine dimensions and materials based on design specifications/requirements. These calculations also included finding face heat generation, power consumption, contact pressure, running torque, and pressure velocity factor. Results from the calculations as well as testing proved that Seal Team 21’s design is a practical solution to the current problem. Further testing and experimentation will continue to prove the concept’s validity for the eVTOL market
Electric Potential Induced Prevention and Removal of an Algal Biofoulant from Planar SERS Substrates
No full textUlva zoospores are widespread marine macroalgae and a common organism found in biofouling communities due to their strong adhesive properties and quick settlement times. Using Ulva as a model organism, a strategy is presented where direct-current (DC) electric potentials are applied in conjunction with surface-enhanced Raman spectroscopy (SERS) to characterize, remove, and prevent Ulva from forming a biofilm on gold-capped nanopillar SERS substrates. Experiments were conducted within a poly(tetrafluoroethylene) (PTFE) flow channel device where the SERS substrates were used as an electrode. Ulva density, determined in situ by SERS and ex situ by electron and fluorescence microscopy, decreased under successively increasing low negative potentials up to −1.0 V. The presence of damaged Ulva suggests that the applied potential led to spore rupture. At the highest negative applied potential (−1.0 V), microparticles containing copper, which is known for its antimicrobial properties, were associated with Ulva on the SERS substrate and the lowest Ulva density was observed. These findings indicate that (1) SERS can be employed to study biofilm formation on nanostructured metal surfaces and (2) applying low-voltage electric potentials may be used to control Ulva biofouling on SERS marine sensors
Discerning Watershed Response to Hydroclimatic Extremes with a Deep Convolutional Residual Regressive Neural Network
No full textThe impact of climate change continues to manifest itself daily in the form of extreme events and conditions such as droughts, floods, heatwaves, and storms. Better forecasting tools are mandatory to calibrate our response to these hazards and help adapt to the planet’s dynamic environment. Here, we present a deep convolutional residual regressive neural network (dcrrnn) platform called Flux to Flow (F2F) for discerning the response of watersheds to water-cycle fluxes and their extremes. We examine four United States drainage basins of varying acreage from smaller to very large (Bear, Colorado, Connecticut, and Mississippi). F2F combines model and ground observations of water-cycle fluxes in the form of surface runoff, subsurface baseflow, and gauged streamflow. We use these time series datasets to simulate, visualize, and analyze the watershed basin response to the varying climates and magnitudes of hydroclimatic fluxes in each river basin. Experiments modulating the time lag between remotely sensed and ground-truth measurements are performed to assess the metrological limits of forecasting with this platform. The resultant mean Nash–Sutcliffe and Kling–Gupta efficiency values are both greater than 90%. Our results show that a hydrological machine learning platform such as F2F can become a powerful resource to simulate and forecast hydroclimatic extremes and the resulting watershed responses and natural hazards in a changing global climate
Deep Learning-Based Classification of Finger Movements using tEEG and EEG Signals
No full textMapping electroencephalography (EEG) signals obtained during hand and finger movements to left or right hands has applications in many fields including motor imagery brain-computer interface (MI-BCI) systems. MI-BCI systems are innovative technology to assist patients with severe motor impairments, however, novice users can face the BCI-illiteracy issue and fail to control the system. A step towards assisting such patients is to correctly classify their EEG signals collected while the patients imagine or perform hand/finger movements. This work considers using the tripolar electroencephalography (tEEG) instead of the traditional EEG due to higher signal-to-noise (SNR), better spatial resolution, better artifact noise rejection feature, and ability to capture high-frequency features of tEEG, compared to conventional EEG. In this paper, we compare the performance of tEEG and EEG signals in classifying motor imagery (MI) of right and left index fingers by using a deep learning algorithm: convolutional neural network (CNN). The results show that in 5 out of 7 subjects, CNN is able to perform classification with high accuracy, with the highest accuracy being 96.4% for tEEG data