| 1. |
- Ahlberg, Annika
(author)
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Förståelse av och förhållningssätt till hälsa : några elevers syn på hälsa och skolämnet idrott och hälsa
- 2015
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Licentiate thesis (other academic/artistic)abstract
- The concept of health should not be viewed as one-dimensional, but rather a complex interplay between physical, psychological and social factors (WHO, 2014). The Swedish curriculum highlights that the school’s responsibility is to support pupils’ knowledge and promote health. The purpose of this study, therefore, was to consider pupils understanding of and attitudes towards health in the context of the subject Physical Education and Health (PEH) at school. Data was collected through the use of focus groups, questionnaires and epistolary dialog. The pupils’ ways of describing health were analysed through Zygmunt Bauman’s (2008) consuming theory and Thomas Ziehe’s (1986, 1999) concepts of cultural liberation, cultural expropriation, the performance principle and authenticity. The result shows that the pupils in the study had a good level of understanding about health. They described health as a complex concept in physical, psychological and social terms. This understanding of health affected the pupils in different ways. For example a feeling of pleasure was described by pupils who appeared well-grounded and spontaneous, while those who experienced pressure in their daily life expressed feelings of higher expectations regarding their own health practices. PEH teachers need to consider not only knowledge content of the subject area, but also variations of self-image among the pupils in their class, and the impact this can have on the way pupils un-derstand the health messages being taught in the classroom.
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| 2. |
- Ahlberg Tidblad, Annika, et al.
(author)
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Future Material Developments for Electric Vehicle Battery Cells Answering Growing Demands from an End-User Perspective
- 2021
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In: Energies. - : MDPI. - 1996-1073. ; 14:14
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Research review (peer-reviewed)abstract
- Nowadays, batteries for electric vehicles are expected to have a high energy density, allow fast charging and maintain long cycle life, while providing affordable traction, and complying with stringent safety and environmental standards. Extensive research on novel materials at cell level is hence needed for the continuous improvement of the batteries coupled towards achieving these requirements. This article firstly delves into future developments in electric vehicles from a technology perspective, and the perspective of changing end-user demands. After these end-user needs are defined, their translation into future battery requirements is described. A detailed review of expected material developments follows, to address these dynamic and changing needs. Developments on anodes, cathodes, electrolyte and cell level will be discussed. Finally, a special section will discuss the safety aspects with these increasing end-user demands and how to overcome these issues.
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| 3. |
- Ahlberg Tidblad, Annika, et al.
(author)
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Surface analysis with ESCA and GD-OES of the film formed by cathodic reduction of chromate
- 1991
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In: Electrochimica Acta. ; 36:10, s. 1605-1610
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Journal article (peer-reviewed)abstract
- In the chlorate process, a small addition of chromate to the electrolyte results in the formation of a cathode film, which inhibits the reduction of the intermediate hypochlorite ions. To enable surface characterization of the chromium film, it was grown by cathodic reduction onto gold and platinum substrates in hydroxide and chlorate solution. Surface analyses of this film by ESCA and GD-OES indicate that it has a distinct and constant chemical composition during growth given by the formula Cr(OH)3·xH2O. The film is thin, less than 50 Å on platinum and 80 Å on gold. It exhibits poor conductivity and covers the entire cathode surface. © 1991.
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| 4. |
- Ahlberg Tidblad, Annika
(author)
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Surface characterization of the chromium hydroxide and basic calcic deposition layers formed on the steel cathode in the chlorate production process
- 1999
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Doctoral thesis (other academic/artistic)abstract
- During technical service, the surface of the steel cathodein the chlorate production process changes with respect tochemical composition and morphology. Deposition of insolublespecies from the electrolyte and corrosion products from thebase metal accumulate and form surface layers that influencethe cathode activity with regards to hydrogen evolution, theprimary reaction, as well as to various parasitic reactions.Improving the activity on the cathode side could reduce theproduction cost of chlorate significantly. Surface analysis hasbeen performed on the thin film formed by reduction of chromateand the layer consisting of basic calcium and magnesiumspecies.Small amounts of sodium chromate are added to the chloratebrine in order to improve the current efficiency of theprocess. Chromate is reduced and forms a thin film withselective permeability that hinders parasitic reduction ofhypochlorite and chlorate ions.Ex situsurface analysis with ESCA and GD-OES were usedin combination within situspectroscopic ellipsometry. Several experimentaldifficulties had to be overcome in order to performellipsometric measurements. The surface film was identified asa hydrated chromium(III) hydroxide, Cr(OH)3*x H2O. The film grows homogeneously on the substrateand attains a maximum thickness of 1-10 nm, depending onchromate concentration, cathodic polarization and substratematerial. The thickness of a monolayer is approximately 0.5 nm.The chemical composition and structural arrangement areconstant during growth and dissolution of the surface productsignificant.Industrial brine contains ppm levels of calcium andmagnesium impurities and carbonate and sulfate ions,<1 g l-1Na2CO3and 10-20 g l-1Na2SO4. Hydrogen gas evolution produces hydroxide ionsand a steep gradient with elevated pH forms in the vicinity ofthe cathode, where various calcium and magnesium saltsprecipitate and form a thick surface layer, 1-1000 µm. Thecalcic deposit is nonconductive and causes cathodicoverpoteniallosses. Characterization using SEM/EDS shows thatthe layer consists of a mixture of calcium hydroxide/carbonate,magnesium hydroxide and sodium sulfate species, which wasconfirmed by an independent kinetic model. The model treatscomplex chemical processes in great detail and employsliterature data for model parameters. To the author'sknowledge, this is the first published attempt at modeling thechemical aspects of the formation of the calcic layer. Thecalcium/magnesium ratio is 3-5, which is higher than predictedby the model, due to the superior ability of calcium to formsoluble complexes and precipitate close enough to beincorporated in the surface layer. High calcium concentrationspromote distinct crystals and dense deposits. Magnesium reducesparticle size and increases the insulating properties of thelayer. Carbonate and sulfate ions contribute to increasingstructural disorder. Precipitation of sodium sulfate onlyoccurs above a critical concentration of sulfate, estimated to25 g l-1Na2SO4. Sodium sulfate precipitates as Na2SO4or as NaClO3*3Na2SO4at high chlorate concentrations.Key words: chlorate cathode processes,chromium(III)hydroxide film, calcic deposit, ESCA, GD-OES,SEM/EDS, spectroscopic ellipsometry, kinetic modeling
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| 5. |
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| 7. |
- Feeney, Laura Marie, et al.
(author)
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Poster Abstract: Using batteries wisely
- 2012. - 7
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Conference paper (peer-reviewed)abstract
- We describe early results from a program of experiments to characterize battery operation in the WSN regime.
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| 8. |
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| 9. |
- Göransson, Gert, 1967, et al.
(author)
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Characterisation of pulse plated Ni and Ni-Zn alloys.
- 2014
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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 161
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Journal article (peer-reviewed)abstract
- Nickel, zinc and nickel-rich NiZn alloys were formed on platinum by galvanostatic pulse plating from aqueous sulfate baths. The alloys were formed in three steps, first in anomalous deposition by a current pulse, secondly by dissolution and oxidation during the open circuit potential in each cycle and finally by anodic stripping of the fully plated sample. The treatment leaves a stable phase with an alloy composition of Ni0.8Zn0.2. The potential-time curves during the plating procedure were used to qualitatively describe the nucleation and growth processes. For Zn a fully covered surface was obtained after one pulse while for Ni and NiZn three-dimensional clusters were obtained in the first pulse. Further growth of these layers involves nucleation on the substrate and deposited clusters. The films were characterized with optical microscopy, SEM/EDX, AFM, XPS, TEM and by electrochemical methods. XPS revealed that the surfaces become gently oxidized by the stripping in the plating solution. For Ni a bi-layer of NiO/Ni(OH)2 was found on the surface while for NiZn mainly the hydroxide was detected. The electrocatalytic properties of the layers toward oxygen reduction in alkaline solution were explored and the NiZn alloy was proven to be an excellent catalyst for hydrogen peroxide production.
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| 13. |
- Kalengayi, Faustine K Nkulu, et al.
(author)
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'It is a dilemma' : perspectives of nurse practitioners on health screening of newly arrived migrants
- 2015
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In: Global Health Action. - : Informa UK Limited. - 1654-9716 .- 1654-9880. ; 8
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Journal article (peer-reviewed)abstract
- Background: Screening newly arrived migrants from countries with high burden of communicable diseases of public health significance is part of the Swedish national strategy against the spread of these diseases. However, little is known about its implementation. Objective: This study aimed at exploring caregivers' experiences in screening newly arrived migrants to generate knowledge that could inform policy and clinical practice. Design: Using an interpretive description framework, we conducted semistructured interviews between November and December 2011 in four Swedish counties, with 15 purposively selected nurses with experience in screening migrants. Data were analyzed using thematic analysis. Results: Participants described a range of challenges including discordant views between migrants and the nurses about medical screening, inconsistencies in rules and practices, and conflicting policies. Participants indicated that sociocultural differences resulted in divergent expectations with migrants viewing the participants as agents of migration authorities. They also expressed concern over being given a new assignment without training and being expected to share responsibilities with staff from other agencies without adequate coordination. Finally, they indicated that existing policies can be confusing and raise ethical issues. All these were compounded by language barriers, making their work environment extremely complex and stressful. Conclusions: These findings illuminate complex challenges that could limit access to, uptake, and delivery of health screening and undermine public health goals, and highlight the need for a multilevel approach. This entails avoiding the conflation of migration with health issues, harmonizing existing policies to make health care services more accessible and acceptable to migrants, and facilitating health professionals' work in promoting public health, improving interagency collaboration and the skills of all staff involved in understanding and effectively responding to migrants' needs, and improving migrants' health literacy through community outreach interventions.
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| 14. |
- Klink, Jacob, et al.
(author)
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Thermal fault detection by changes in electrical behaviour in lithium-ion cells
- 2021
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In: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 490
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Journal article (peer-reviewed)abstract
- With this paper a method to detect faults of lithium-ion cells during operation is first presented and later validated by experiment. Since every cell fault will increase the cell temperature towards its process until thermal runaway the method uses the temperature-dependent change of the cell impedance as fault feature. Using a 46 Ah pouch cell the model was parameterised by electrochemical impedance spectroscopy and then validated during dynamic load. For this purpose the Worldwide harmonised Light vehicles Test Procedure (WLTP) was chosen. The presence of a fault was simulated by heating the cell once uniformly and once locally and the progression of the chosen fault feature analysed. For both test cases the method proposed was able to detect the present heat source before the thermal runaway was triggered and venting or voltage drop were observed.
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| 15. |
- Ma, Yi, 1982, et al.
(author)
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A mechanistic study of electrodeposition of bismuth telluride on stainless steel substrates
- 2010
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In: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 55:15, s. 4610-4617
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Journal article (peer-reviewed)abstract
- Miniaturization of Bi2Te3 compounds is of great interest in semiconductor industries due to their distinct anisotropic thermoelectric properties at room temperature. The aim of the present work was to investigate the mechanism of the electrodeposition of Bi2Te3 compounds on stainless steel substrates and relate the morphology and composition of the resulting deposits to experimental parameters. Cyclic voltammetry (CV) experiments in acidic solutions containing Bi3+ and/or HTeO2+ ions show that the deposition potential for the Bi2Te3 compound is more positive than either of the single elements alone. A detailed mechanism of the co-deposition was obtained by varying the concentrations of the two elements and evaluating the corresponding morphological and compositional changes of the deposits. The results show that the deposition of Te is kinetically hindered and that Bi deposition plays a major role during the co-deposition.
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| 16. |
- Nilsson, Elna JK, et al.
(author)
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Evaluation of combustion properties of vent gases from Li-ion batteries
- 2023
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In: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 585
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Journal article (peer-reviewed)abstract
- Fire incidents involving Li-ion batteries is an increasing concern as the use of battery electric vehicles is increasing. Abuse conditions such as heating can result in ejection of flammable and toxic gases, presenting a health risk and risk of explosion or fire. The purpose of the present work is to increase the understanding of combustion of gas mixtures vented from Li-ion batteries. The investigation uses a new merged kinetic mechanism including hydrocarbons, hydrogen, carbon oxides, carbonates and fluorinated compounds. Seven typical Li-ion vent gas mixtures were selected based on published studies, and ignition and laminar flames were simulated. Modeling reveal a large variation in laminar burning velocity, flame temperature and heat release. Determining factors for laminar flames are the relative content of the carbonates and hydrogen gas, and the inert carbon dioxide. Gases from highly charged battery cells have the shortest ignition time at high temperatures and the fastest laminar burning velocity. The results can be used as input in computational fluid dynamics or safety engineering modeling. In addition, the versatile kinetic model can be used for fundamental studies of the combustion process and for generation of combustion characteristics such as laminar burning velocities for other vent gas mixtures.
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| 17. |
- Nkulu Kalengayi, Faustine, et al.
(author)
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Perspectives and experiences of new migrants on health screening in Sweden
- 2016
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In: BMC Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; 16:14
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Journal article (peer-reviewed)abstract
- Background: In Sweden, migrants from countries considered to have a high burden of certain infectious diseases are offered health screening to prevent the spread of these diseases, but also identify their health needs. However, very little is known about their experiences and perceptions about the screening process. This study aimed at exploring these perceptions and experiences in order to inform policy and clinical practice. Method: Using an interpretive description framework, 26 new migrants were interviewed between April and June 2013 in four Swedish counties. Thematic analysis was used to analyze data. Results: The three themes developed include: new country, new practices; new requirements in the new country; and unmet needs and expectations. Participants described what it meant for them to come to a new country with a foreign language, new ways of communicating with caregivers/authorities and being offered health screening without clarification. Participants perceived health screening as a requirement from the authorities to be fulfilled by all newcomers but conceded that it benefits equally the host society and themselves. However, they also expressed concern over the involvement of the Migration Board staff and feared possible collaboration with health service to their detriment. They further stated that the screening program fell short of their expectations as it mainly focused on identifying infectious diseases and overlooked their actual health needs. Finally, they expressed frustration over delay in screening, poor living conditions in reception centers and the restrictive entitlement to care. Conclusions: Migrants are aware of their vulnerability and the need to undergo health screening though they view it as an official requirement. Thus, those who underwent the screening were more concerned about residency rather than the actual benefits of screening. The issues highlighted in this study may limit access to and uptake of the screening service, and compromise its effectiveness. To maximize the uptake: (1) linguistically and culturally adapted information is needed, (2) other screening approaches should be tried, (3) trained medical interpreters should be used, (4) a holistic and human right approach should be applied, (5) the involvement of migration staff should be reconsidered to avoid confusion and worries. Finally, to improve the effectiveness, (6) all migrants from targeted countries should be offered screening and efforts should be taken to improve the health literacy of migrants and the living conditions in reception centers.
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| 18. |
- Owen, Rhodri E., et al.
(author)
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Operando Ultrasonic Monitoring of Lithium-Ion Battery Temperature and Behaviour at Different Cycling Rates and under Drive Cycle Conditions
- 2022
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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 169:4
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Journal article (peer-reviewed)abstract
- Effective diagnostic techniques for Li-ion batteries are vital to ensure that they operate in the required voltage and temperature window to prevent premature degradation and failure. Ultrasonic analysis has been gaining significant attention as a low cost, fast, non-destructive, operando technique for assessing the state-of-charge and state-of-health of Li-ion batteries. Thus far, the majority of studies have focused on a single C-rate at relatively low charge and discharge currents, and as such the relationship between the changing acoustic signal and C-rate is not well understood. In this work, the effect of cell temperature on the acoustic signal is studied and shown to have a strong correlation with the signal's time-of-flight. This correlation allows for the cell temperature to be inferred using ultrasound and to compensate for these effects to accurately predict the state-of-charge regardless of the C-rate at which the cell is being cycled. Ultrasonic state-of-charge monitoring of a cell during a drive cycle illustrates the suitability of this technique to be applied in real-world situations, an important step in the implementation of this technique in battery management systems with the potential to improve pack safety, performance, and efficiency:
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| 19. |
- Robinson, James B., et al.
(author)
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Identifying Defects in Li-Ion Cells Using Ultrasound Acoustic Measurements
- 2020
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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 167:12
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Journal article (peer-reviewed)abstract
- Identification of the state-of-health (SoH) of Li-ion cells is a vital tool to protect operating battery packs against accelerated degradation and failure. This is becoming increasingly important as the energy and power densities demanded by batteries and the economic costs of packs increase. Here, ultrasonic time-of-flight analysis is performed to demonstrate the technique as a tool for the identification of a range of defects and SoH in Li-ion cells. Analysis of large, purpose-built defects across multiple length scales is performed in pouch cells. The technique is then demonstrated to detect a microscale defect in a commercial cell, which is validated by examining the acoustic transmission signal through the cell. The location and scale of the defects are confirmed using X-ray computed tomography, which also provides information pertaining to the layered structure of the cells. The demonstration of this technique as a methodology for obtaining direct, non-destructive, depth-resolved measurements of the condition of electrode layers highlights the potential application of acoustic methods in real-time diagnostics for SoH monitoring and manufacturing processes.
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| 20. |
- Sturk, David, et al.
(author)
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Analysis of li-ion battery gases vented in an inert atmosphere thermal test chamber
- 2019
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In: Batteries. - : MDPI Multidisciplinary Digital Publishing Institute. - 2313-0105. ; 5:3
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Journal article (peer-reviewed)abstract
- One way to support the development of new safety practices in testing and field failure situations of electric vehicles and their lithium-ion (Li-ion) traction batteries is to conduct studies simulating plausible incident scenarios. This paper focuses on risks and hazards associated with venting of gaseous species formed by thermal decomposition reactions of the electrolyte and electrode materials during thermal runaway of the cell. A test set-up for qualitative and quantitative measurements of both major and minor gas species in the vented emissions from Li-ion batteries is described. The objective of the study is to measure gas emissions in the absence of flames, since gassing can occur without subsequent fire. Test results regarding gas emission rates, total gas emission volumes, and amounts of hydrogen fluoride (HF) and CO2 formed in inert atmosphere when heating lithium iron phosphate (LFP) and lithium nickel-manganese-cobalt (NMC) dioxide/lithium manganese oxide (LMO) spinel cell stacks are presented and discussed. Important test findings include the large difference in total gas emissions from NMC/LMO cells compared to LFP, 780 L kg−1 battery cells, and 42 L kg−1 battery cells, respectively. However, there was no significant difference in the total amount of HF formed for both cell types, suggesting that LFP releases higher concentrations of HF than NMC/LMO cells. © 2019 by the authors.
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| 21. |
- Sturk, David, et al.
(author)
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Fire Tests on E-vehicle Battery Cells and Packs
- 2015
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In: Traffic Injury Prevention. - : Taylor and Francis Inc.. - 1538-9588 .- 1538-957X. ; 16, s. 159-164
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Journal article (peer-reviewed)abstract
- Objective: The purpose of this study was to investigate the effects of abuse conditions, including realistic crash scenarios, on Li ion battery systems in E-vehicles in order to develop safe practices and priorities when responding to accidents involving E-vehicles. Method: External fire tests using a single burning item equipment were performed on commercial Li ion battery cells and battery packs for electric vehicle (E-vehicle) application. The 2 most common battery cell technologies were tested: Lithium iron phosphate (LFP) and mixed transition metal oxide (lithium nickel manganese cobalt oxide, NMC) cathodes against graphite anodes, respectively. The cell types investigated were “pouch” cells, with similar physical dimensions, but the NMC cells have double the electric capacity of the LFP cells due to the higher energy density of the NMC chemistry, 7 and 14 Ah, respectively. Heat release rate (HRR) data and concentrations of toxic gases were acquired by oxygen consumption calorimetry and Fourier transform infrared spectroscopy (FTIR), respectively. Results: The test results indicate that the state of charge (SOC) affects the HRR as well as the amount of toxic hydrogen fluoride (HF) gas formed during combustion. A larger number of cells increases the amount of HF formed per cell. There are significant differences in response to the fire exposure between the NMC and LFP cells in this study. The LFP cells generate a lot more HF per cell, but the overall reactivity of the NMC cells is higher. However, the total energy released by both batteries during combustion was independent of SOC, which indicates that the electric energy content of the test object contributes to the activation energy of the thermal and heat release process, whereas the chemical energy stored in the materials is the main source of thermal energy in the batteries. Conclusions: The results imply that it is difficult to draw conclusions about higher order system behavior with respect to HF emissions based on data from tests on single cells or small assemblies of cells. This applies to energy release rates as well. The present data show that mass and shielding effects between cells in multicell assemblies affect the propagation of a thermal event.
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| 22. |
- Söderberg, Annika, et al.
(author)
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From fear to fight : Patients experiences of early mobilization in intensive care. A qualitative interview study
- 2022
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In: Physiotherapy Theory and Practice. - : Taylor & Francis. - 0959-3985 .- 1532-5040. ; 38:6, s. 750-758
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Early mobilization (EM) in intensive care is frequently used to prevent physical and psychological complications, with promising results. However, the patient´s perception of EM has been sparsely investigated. Purpose : To investigate the experience of EM in patients treated in intensive care. Method : Nineteen former patients who had been treated in intensive care were interviewed. The interviews were analyzed using qualitative, inductive content analysis. Results : The analysis resulted in three categories; 1) Facing the impossible - a too demanding situation; 2) Struggling successfully on the way back; and 3) Need of having dedicated supporters. Conclusion : A considerable variety of experiences of EM were described in this study, both negative and positive. Prominent features were that pleasant emotions and great physical effort occurred simultaneously and that interaction and cooperation with the caregivers was paramount. To regain independence was another prominent feature, with EM considered to be of great importance in the recovery process. Moving to an upright position and ambulating appears to be beneficial to both body and mind. EM should therefore be among the first priorities in intensive care. EM should be practiced with respect and support, while encouraging and challenging the patient to strive for independence.
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