Publikationer från Uppsala Universitet
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Improved Efficiency of Carbon-Based Perovskite Solar Cells by Using Alternative Solvent for Doping-Free P3HT
No full textLow-temperature-processed carbon-based perovskite solar cells (C-PSCs) are a potential candidate for industrial development, due to their low cost, high stability, and easy preparation methods. However, their power conversion efficiencies still lag behind that of metal-contact-based PSCs, due to poor compatibility of the carbon electrode with the underlying layers. Here, we introduce a doping-free poly(3-hexylthiophene) (P3HT) hole-transport layer deposited from chloroform to improve solar cell performance of PSCs that are prepared in ambient air. The resulting P3HT films have a lower roughness and a higher conductivity. A champion device with power conversion efficiency of 19.4% was obtained with negligible hysteresis and a remarkably enhanced fill factor (FF) of 80.2%. Unencapsulated devices maintained 70% of initial efficiency value after 350 hr under thermal stress at 85 degrees C in dark and ambient air
Poor sleep is associated with lower physical activity in a population-based cohort of middle-aged and older adults
No full textSleep problems and inadequate physical activity (PA) are associated with numerous adverse health outcomes. Most studies explored the influence of PA on sleep, but how sleep affects engagement in PA across adulthood remains less well investigated. This study examined the association between sleep traits and PA reported the following year in 51,247 Swedish women and men (55–93 years), who completed questionnaires regarding their sleep, PA, and other characteristics. Health status was assessed with data from the Swedish National Patient Registry. Odds ratios and 95% confidence intervals were estimated by binary logistic regression. In multivariable analysis, long sleep duration (≥ 9 h/night), sleep disturbance, and symptoms of sleep-disordered breathing (SDB) were associated with lower odds of engaging in walking or cycling, and exercising the following year. In addition, short sleep duration (< 7 h/night), sleep disturbance, and symptoms of SDB were linked to sedentary behavior (time spent on reading or watching TV). Several sex- and age-specific associations were observed. In addition to previous evidence of a positive effect of PA on sleep, our findings indicate that poor sleep may contribute to lower engagement in PA and a higher level of sedentary behavior, highlighting the bidirectional nature of the relationship between PA and sleep
And then I made some pockets of change : Collage-making to think presents and futures of engineering education with
No full textWhat stories can we tell to think higher engineering education futures with? How can we imagine what practices are possible? How can we transgress what hasn’t served us, other critters, and the planet? These are questions that inspired us to develop a workshop in which we used collage-making to visualize narratives on current states of engineering education, as well as to transgress them to envision other possible futures. Grounded in Holland et al.’s (1998) theory of Figured Worlds and Lönngren and Berge’s concept of Emotional Positioning, the workshop explored figured emotional worlds operating in engineering classrooms and imagined possible futures. Here, we 1) map out the progression of the activity, 2) share examples of collages and their stories, and 3) provide multiple dimensions of reflection, discussing the uses of collages and how they prompted us to imagine, tell, and transgress stories about current and possible futures of higher engineering education
Free water improves sodium mobilization in furosemide treated pigs after a hyperosmotic sodium load
No full textBACKGROUND: Hypernatremia, a common electrolyte disorder in critically ill patients, induces a hyperosmotic state linked to increased mortality and metabolic stress. While loop diuretics such as furosemide are used for fluid management, their main effect is water excretion, often worsening hypernatremia. This study aimed to determine whether free water infusion enhances sodium excretion when combined with furosemide after a sodium chloride bolus. We also hypothesized that hyperosmolar hypernatremia stimulates protein degradation and urea synthesis. RESULTS: Fourteen pigs (seven per group) received a sodium chloride bolus to induce hypernatremia (plasma Na⁺ > 150 mmol/L). One group received furosemide alone, while the other received furosemide plus free water to maintain normo-osmolality. Renal and metabolic parameters were analyzed over five hours. Free water infusion significantly lowered plasma sodium levels (134 ± 4 vs. 150 ± 4 mmol/L, p = 1.2e-14) and increased total sodium excretion (99 ± 20 vs. 70 ± 18 mmol, p = 0.00056) and urine output (1860 ± 220 vs. 1200 ± 160 mL, p = 2.47e-05). Fractional sodium excretion was higher with free water (5.3 ± 1.1% vs. 3.5 ± 2.2%, p = 0.012). Plasma glutamine was elevated in the no-water group (1305 ± 209 vs. 1084 ± 110 µmol/L, p = 0.029), indicating greater metabolic stress. CONCLUSIONS: These results suggest that free water infusion enhances sodium clearance and reduces hypernatremia-induced metabolic alterations, supporting its potential role in fluid management strategies
Synthesis, evaluation of in vitro cytotoxic activity, and in silico studies of some 3-methylenamino-4(3H)-quinazolone derivatives
No full textA series of 3-methylenamino-4(3H)-quinazolone derivatives were synthesized by imine formation reactions of 3-amino-6-chloro-2-phenyl-4(3H)-quinazolone with various substituted aromatic aldehydes at 80°C for 1-3 hours using the reflux method. Twenty 3-methylenamino-4(3H)-quinazolone derivatives were synthesized with good to excellent yields (66 to 90%). Compound 5 (2-chloro-6-fluorobenzylidene) exhibited good cytotoxic activity against the RD cell line with an IC50 value of 14.65 μM but exhibited weak cytotoxic activity against the MDA-MB-231 cell line (IC50 = 147.70 μM) compared to the reference drug paclitaxel (PTX, IC50 RD = 0.58 μM and IC50 MDA-MB-231 = 0.04 μM). Meanwhile, compounds 6 (benzo[d][1,3]dioxol-5-ylmethylene) and 7 (4-bromo-2-hydroxybenzylidene) showed good cytotoxic activity against MDA-MB-231 with IC50 values of 10.62 and 8.79 μM, respectively. However, these compounds showed weak cytotoxic activity against the RD cell line (IC50 = 50-55 μM). In particular, potential compounds 5, 6, and 7 exhibited weak cytotoxic activity against the normal cell line LLC-PK1 (IC50 = 34.82-60.18 μM) compared to the highly toxic agent PTX (IC50 = 1.31 μM). Furthermore, compounds 5, 6, and 7 showed strong interactions with the EGFR target with binding affinities of -9.6, -10.1, and -9.8 kcal mol-1, respectively, compared to reference drug Gefitinib (-7.8 kcal mol-1). The in silico ADMET results suggested that these potent derivatives possess a good ADMET profile. Therefore, these three compounds are potential candidates for novel cancer drug development, as demonstrated by in vitro and in silico studies
ICE CLASSIFICATION ON WIND TURBINE BLADE USING RECURRENT NEURAL NETWORKS WITH ATTENTION LAYER
No full textThe wind industry is expanding and areas in cold and remote locations can have good potential for location of wind turbines. Due to the cold climate ice can occur on sensors, wind turbine and the blades. The annual production losses can according to IEA be up to 20% in some areas located in the north. Methods to prevent ice on the blades can be using anti or de-icing systems. The wind turbines can also be shut down to prevent damage on the equipment due to ice conditions or for safety reasons such as risk for ice throw. Ice detection is an important part considering these conditions and for estimating the annual estimated production for sites in cold climate. A method to detect and classify ice from SCADA data is to use deep learning. Deep learning is continuously improving and developed. To increase the performance of deep learning models they can be combined to use the properties for different models together. To increase the performance of a RNN (recurrent neural networks) model the proposed models in this paper is RNN with added attention layer. Three RNN models is used with and without attention layer in order to compare the results. The models is LSTM (Long term short term memory), GRU (Gated recurrent unit) and SimpleRNN (Simple recurrent neural network). Open-source SCADA data provided by IEA is used for training and validating. The result shows increase in accuracy for each model and increase in F1 scores, both with respect to classification of true positive and true negative. This means that the models are more balanced with higher precision and recall. The highest increase for F1 score (true positive) was 0,86% for LSTM with attention layer and the highest increase for F1 score (true negative) was 1,19% for SimpleRNN model. The highest accuracy increase was also for SimpleRNN with attention layer by 0,86%. The overall highest performance had LSTM with attention with an accuracy of 0,922 and F1 score (true positive) 0,925. When compared to other study using the same open- source data the RNN models used in this study had high performance. The performance was high both with and without attention layer with an accuracy >0,907 and F1 score over >0,909 for each model
"Trust, Responsibility, and Making a Difference" : Qualitative Insights into Why First-Line Managers in Healthcare Remain in Their Role
No full textHealthcare organizations face increasing challenges in retaining first-line managers, who play a key role in operational stability and patient care. Studies indicate that approximately half of all first-line managers intend to leave their position within 5 years. This highlights the need for updated knowledge about conditions under which they work. A qualitative descriptive design was used to explore first-line managers’ perceptions of what is important for them to remain in the managerial role. Data were collected through 20 individual semi-structured interviews with first-line managers from a medium-sized healthcare organization in Sweden between March and June 2022. The data were analyzed using qualitative content analysis. The results are presented through the overarching theme Empowered through support, responsibility, and meaningful contribution. This theme describes how first-line managers sustain their motivation and commitment by developing confidence in their ability to lead, influence others, and create meaningful change. Their confidence is grounded in support, responsibility, and role clarity. The theme also shows how first-line managers handle challenges, make decisions, and act to improve staff well-being and patient care. Through these actions, they contribute to the development of their units. Trust from their manager, autonomy in decision-making, and support from colleagues enhance first-line managers’ sense of purpose and motivation, encouraging them to remain in their role. Moreover, balanced workloads and opportunities to make a meaningful impact strengthen their commitment. By recognizing and addressing these aspects, healthcare organizations can better support long-term engagement of first-line managers, fostering sustainable leadership and stability
Vietjere : an essay about the Sámi drum hammers and their find contexts
No full textSyften med denna uppsats var att undersöka den samiska trumhammaren, vietjere, och de olika fyndkontexterna som gjort att de hamnat i samlingarna, för att se om de kunde visa vilken betydelse och agens vietjere haft i olika sammanhang. Sedan Ernst Mankers omfattande bok om trumman och alla dess rituella föremål kom ut 1938, har forskningen mest behandlat enstaka vietjere och fyndsammanhang, allt eftersom de hittats. Ett helhetsgrepp över samtliga fyndkontexter har saknats. I uppsatsen analyseras de idag 59 kända vietjere och deras olika fyndkontexter, för att se vilka likheter och skillnader som finns som kan ge fördjupade insikter om de haft olika ideologiska och rituella betydelser. Teorin som använts i uppsatsen är den objektbiografiska, eftersom den har stora likheter med det samiska tankesättet att allt är levande och har ett liv och relationer med sin omgivning. Analysen av vietjere och fyndkontexter indikerar att det finns likheter men även skillnader ideologiskt och rituellt dem emellan. Analysen visar även att vietjere sannolikt haft en egen agens även utan trumman. Och att den haft olika betydelser för människor i olika sammanhang under sin livstid. The purpose of this essay was to examine the Sami drum hammer, vietjere, and the various find contexts that have led to their inclusion in collections, to see if they could show what significance and agency vietjere have had in different contexts. Since Ernst Manker's extensive book on the drum and all its ritual objects was published in 1938, research has primarily focused on occasional vietjere and find contexts as they have been discovered. A comprehensive overview of all find contexts has been lacking. The essay analyses the currently 59 known vietjere and the different find contexts to see what similarities and differences exist, that can provide deeper insights into whether they had different ideological and ritual meanings. The theory used in the thesis is the object-biographical, as it has strong similarities with the Sámi way of thinking that everything is alive and has a life and relationships with its surroundings. The analysis of vietjere and find context indicates that there are similarities but also ideological and ritual differences among them. The analysis also shows that vietjere likely had its own agency even without the drum. And that it had different meanings for people in various contexts during its lifetime
Switching between Limiting Charge Extraction Regimes in an Illuminated Semiconductor–Metal–Organic Framework Junction
No full textSurface modification is an effective method to realize high performance photoelectrodes. While current investigations mostly aim to leverage surface layers for improved charge carrier kinetics during charge separation, interfacial charge transfer, and decreased recombination, carrier transport within the surface layer is largely unattended. Herein, we explore this charge transport process on a model photocathode consisting of p-Si and GaP semiconductors (SCs) that are coated with a redox-active Zn-NDI (NDI = naphthalene diimide bis-pyrazolate) metal–organic framework (MOF) surface layer. The MOF layer is able to accept photogenerated electrons and support a large photovoltage of the underlying SC. In addition to well-established carrier generation and interfacial transfer processes that are frequently considered to control photocurrents, experimental photoelectrochemical data of the MOF@SC electrodes expose limitations that arise from electron transport in the surface layer coating. The transport-limited regime becomes relevant when the illumination intensity is gradually increased and is sensitive to the nature of the underlying semiconductor as well as the electrolyte. The phenomenon reported in this work is likely present in other surface-modified photoelectrodes with thick cocatalysts or redox-active polymer coatings but can easily be overlooked. In the MOF@SC construct, the transition between different limiting regimes can be visualized owing to the well-behaved cation-coupled photoelectron hopping transport in the MOF layer. These findings support the design and realization of efficient photoelectrodes
Entropy of Lyapunov maximizing measures of SL(2,ℝ) typical cocycles
No full textIn this paper, we study ergodic optimization problems for typical cocycles. We consider one-step SL(2,ℝ)-cocycles that satisfy pinching and twisting conditions (in the sense of [Bonatti, C., and Viana, M. Lyapunov exponents with multiplicity 1 for deterministic products of matrices. Ergodic Theory and Dynamical Systems. 2004;24(5):1295–1330.]). We prove that the Lyapunov maximizing measures have zero entropy under additional assumptions that the maps 1 and 2 are one-to-one on the Mather set