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1,081 results on '"Kulmala, P."'

1. Effects of Physically Active Maths Lessons on Children's Maths Performance and Maths-Related Affective Factors: Multi-Arm Cluster Randomized Controlled Trial

Author

Heidi J. Syväoja, Sirpa Sneck, Tuomas Kukko, Piritta Asunta, Pekka Räsänen, Helena Viholainen, Janne Kulmala, Harto Hakonen, and Tuija H. Tammelin

Abstract

Background: Physical activity (PA) may benefit academic performance, but it is unclear what kind of classroom-based PA is optimal for learning. Aim: We studied the effects of physically active maths lessons on children's maths performance and maths-related effects, and whether gender and previous mathematical or motor skills modify these effects. Sample: A total of 22 volunteered teachers and their pupils with signed consent (N = 397, mean age: 9.3 years, 51% females) participated in a 5-month, teacher-led, multi-arm, cluster-randomized controlled trial. Methods: The intervention included a PAL group (20 min of physically active learning in each 45-min lesson), a breaks group (two 5-min PA breaks in each 45-min lesson) and a control group (traditional teaching). Maths performance was assessed with a tailored curriculum-based test. Maths-related enjoyment, self-perceptions and anxiety were measured with a self-reported questionnaire. The individual-level intervention effects were tested via covariate-adjusted linear mixed-effect models with school classes serving as random effects. Results: Changes in maths performance or self-perceptions did not differ between the intervention groups. Maths anxiety in learning situations increased in the PAL group (effect .28, 95% CI = .01--.56); there was no change in the other groups. Subgroup analyses suggested that maths anxiety increased in the PAL group among children in the two lowest tertiles of motor skills. It decreased in the highest tertile. Enjoyment decreased in the breaks group among pupils in the lowest motor skill tertile. Conclusions: Physically active maths lessons did not affect maths performance or self-perceptions but had divergent effects on maths anxiety and enjoyment, depending on motor skills.

Published
2024
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2. Unleashing OpenTitan's Potential: a Silicon-Ready Embedded Secure Element for Root of Trust and Cryptographic Offloading

Author

Ciani, Maicol, Parisi, Emanuele, Musa, Alberto, Barchi, Francesco, Bartolini, Andrea, Kulmala, Ari, Psiakis, Rafail, Garofalo, Angelo, Acquaviva, Andrea, and Rossi, Davide

Subjects
Electrical Engineering and Systems Science - Systems and Control, Electrical Engineering and Systems Science - Signal Processing
Abstract

The rapid advancement and exploration of open-hardware RISC-V platforms are driving significant changes in sectors like autonomous vehicles, smart-city infrastructure, and medical devices. OpenTitan stands out as a groundbreaking open-source RISC-V design with a comprehensive security toolkit as a standalone system-on-chip (SoC). OpenTitan includes Earl Grey, a fully implemented and silicon-proven SoC, and Darjeeling, announced but not yet fully implemented. Earl Grey targets standalone SoC implementations, while Darjeeling is for integrable implementations. The literature lacks a silicon-ready embedded implementation of an open-source Root of Trust, despite lowRISC's efforts on Darjeeling. We address the limitations of existing implementations by optimizing data transfer latency between memory and cryptographic accelerators to prevent under-utilization and ensure efficient task acceleration. Our contributions include a comprehensive methodology for integrating custom extensions and IPs into the Earl Grey architecture, architectural enhancements for system-level integration, support for varied boot modes, and improved data movement across the platform. These advancements facilitate deploying OpenTitan in broader SoCs, even without specific technology-dependent IPs, providing a deployment-ready research vehicle for the community. We integrated the extended Earl Grey architecture into a reference architecture in a 22nm FDX technology node, benchmarking the enhanced architecture's performance. The results show significant improvements in cryptographic processing speed, achieving up to 2.7x speedup for SHA-256/HMAC and 1.6x for AES accelerators compared to the baseline Earl Grey architecture.

Published
2024
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3. New particle formation from isoprene under upper-tropospheric conditions

Author

Shen, Jiali, Russell, Douglas M., DeVivo, Jenna, Kunkler, Felix, Baalbaki, Rima, Mentler, Bernhard, Scholz, Wiebke, Yu, Wenjuan, Caudillo-Plath, Lucía, Sommer, Eva, Ahongshangbam, Emelda, Alfaouri, Dina, Almeida, João, Amorim, Antonio, Beck, Lisa J., Beckmann, Hannah, Berntheusel, Moritz, Bhattacharyya, Nirvan, Canagaratna, Manjula R., Chassaing, Anouck, Cruz-Simbron, Romulo, Dada, Lubna, Duplissy, Jonathan, Gordon, Hamish, Granzin, Manuel, Große Schute, Lena, Heinritzi, Martin, Iyer, Siddharth, Klebach, Hannah, Krüger, Timm, Kürten, Andreas, Lampimäki, Markus, Liu, Lu, Lopez, Brandon, Martinez, Monica, Morawiec, Aleksandra, Onnela, Antti, Peltola, Maija, Rato, Pedro, Reza, Mago, Richter, Sarah, Rörup, Birte, Sebastian, Milin Kaniyodical, Simon, Mario, Surdu, Mihnea, Tamme, Kalju, Thakur, Roseline C., Tomé, António, Tong, Yandong, Top, Jens, Umo, Nsikanabasi Silas, Unfer, Gabriela, Vettikkat, Lejish, Weissbacher, Jakob, Xenofontos, Christos, Yang, Boxing, Zauner-Wieczorek, Marcel, Zhang, Jiangyi, Zheng, Zhensen, Baltensperger, Urs, Christoudias, Theodoros, Flagan, Richard C., El Haddad, Imad, Junninen, Heikki, Möhler, Ottmar, Riipinen, Ilona, Rohner, Urs, Schobesberger, Siegfried, Volkamer, Rainer, Winkler, Paul M., Hansel, Armin, Lehtipalo, Katrianne, Donahue, Neil M., Lelieveld, Jos, Harder, Hartwig, Kulmala, Markku, Worsnop, Doug R., Kirkby, Jasper, Curtius, Joachim, and He, Xu-Cheng

Published
2024
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4. Student behaviour and engagement with adaptive exercises on a thermodynamics course

Author

Harjula, Matti, Havu, Ville, Kontro, Inkeri, Kulmala, Kimmo, Malinen, Jarmo, and Salo, Petri

Subjects
Physics - Physics Education, 97U50, K.3.1
Abstract

A teaching experiment was carried out in a university-level thermodynamics course using adaptive and interactive e-learning material, created in the new Moodle question type Stateful extending the original e-learning platform STACK. The system collects data about the students that is used to algorithmically classify them according to their behaviour in solving problems. It is observed that the classification of this data predicts students' success in the other parts of the course for a majority of students. Also, the classification is statistically consistent with Thermodynamic Concept Survey and Maryland Physics Expectation Survey.

Published
2024

6. A Heterogeneous RISC-V based SoC for Secure Nano-UAV Navigation

Author

Valente, Luca, Nadalini, Alessandro, Veeran, Asif, Sinigaglia, Mattia, Sa, Bruno, Wistoff, Nils, Tortorella, Yvan, Benatti, Simone, Psiakis, Rafail, Kulmala, Ari, Mohammad, Baker, Pinto, Sandro, Palossi, Daniele, Benini, Luca, and Rossi, Davide

Subjects
Computer Science - Hardware Architecture, Computer Science - Artificial Intelligence
Abstract

The rapid advancement of energy-efficient parallel ultra-low-power (ULP) ucontrollers units (MCUs) is enabling the development of autonomous nano-sized unmanned aerial vehicles (nano-UAVs). These sub-10cm drones represent the next generation of unobtrusive robotic helpers and ubiquitous smart sensors. However, nano-UAVs face significant power and payload constraints while requiring advanced computing capabilities akin to standard drones, including real-time Machine Learning (ML) performance and the safe co-existence of general-purpose and real-time OSs. Although some advanced parallel ULP MCUs offer the necessary ML computing capabilities within the prescribed power limits, they rely on small main memories (<1MB) and ucontroller-class CPUs with no virtualization or security features, and hence only support simple bare-metal runtimes. In this work, we present Shaheen, a 9mm2 200mW SoC implemented in 22nm FDX technology. Differently from state-of-the-art MCUs, Shaheen integrates a Linux-capable RV64 core, compliant with the v1.0 ratified Hypervisor extension and equipped with timing channel protection, along with a low-cost and low-power memory controller exposing up to 512MB of off-chip low-cost low-power HyperRAM directly to the CPU. At the same time, it integrates a fully programmable energy- and area-efficient multi-core cluster of RV32 cores optimized for general-purpose DSP as well as reduced- and mixed-precision ML. To the best of the authors' knowledge, it is the first silicon prototype of a ULP SoC coupling the RV64 and RV32 cores in a heterogeneous host+accelerator architecture fully based on the RISC-V ISA. We demonstrate the capabilities of the proposed SoC on a wide range of benchmarks relevant to nano-UAV applications. The cluster can deliver up to 90GOp/s and up to 1.8TOp/s/W on 2-bit integer kernels and up to 7.9GFLOp/s and up to 150GFLOp/s/W on 16-bit FP kernels.

Published
2024
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13. The Effects of Mindfulness-Based Interventions in Medical Students: A Systematic Review

Author

Ilona Kaisti, Petri Kulmala, Mirka Hintsanen, Tuula Hurtig, Saara Repo, Tiina Paunio, Jouko Miettunen, Anu-Helmi Halt, and Erika Jääskeläinen

Abstract

The number of studies on the effects of mindfulness on healthcare professionals is increasing. The main aim of this study was to collate the quantitative results of original studies analyzing the effects of mindfulness-based interventions on a variety of outcomes in medical students. We also analyzed how the study design and characteristics of the intervention affect the results, and identified qualitative effects of mindfulness interventions. A literature search was performed in different databases in June 2020. Original articles meeting the following criteria were included: (1) at least 50% of the participants were medical students, (2) included a mindfulness intervention, (3) analyzed any outcome relating to mindfulness intervention, (4) peer-reviewed (5) written in English. Eventually, 31 articles including 24 different samples were included. Over half of the studies were RCTs. In over half of the studies, the intervention was 4- to 10-week original Mindfulness-Based Stress Reduction or Mindfulness-Based Cognitive Therapy or a modification of these. In general, satisfaction with the interventions was good. Based on a meta-analysis, after the intervention, the intervention group had statistically significantly fewer symptoms of stress and distress and had higher mindfulness than the controls. The beneficial effects persisted in follow-ups over months or years. Both long and shorter courses and courses with and without face-to-face sessions were effective. Both controlled and uncontrolled studies had statistically significant results. Qualitative results revealed potential factors behind the quantitative effects. The number of studies on mindfulness interventions in medical students has increased drastically. Mindfulness-based interventions seem to offer a good possibility to enhance medical students' well-being.

Published
2024
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14. Distribution Network Fault Prediction Utilising Protection Relay Disturbance Recordings And Machine Learning

Author

Balouji, Ebrahim, Bäckström, Karl, Olsson, Viktor, Hovila, Petri, Niveri, Henry, Kulmala, Anna, and Salo, Ari

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

As society becomes increasingly reliant on electricity, the reliability requirements for electricity supply continue to rise. In response, transmission/distribution system operators (T/DSOs) must improve their networks and operational practices to reduce the number of interruptions and enhance their fault localization, isolation, and supply restoration processes to minimize fault duration. This paper proposes a machine learning based fault prediction method that aims to predict incipient faults, allowing T/DSOs to take action before the fault occurs and prevent customer outages.

Published
2023

15. Oxidized organic molecules in the tropical free troposphere over Amazonia

Author

Zha, Qiaozhi, Aliaga, Diego, Krejci, Radovan, Sinclair, Victoria, Wu, Cheng, Scholz, Wiebke, Heikkinen, Liine, Partoll, Eva, Gramlich, Yvette, Huang, Wei, Leiminger, Markus, Enroth, Joonas, Peräkylä, Otso, Cai, Runlong, Chen, Xuemeng, Koenig, Alkuin Maximilian, Velarde, Fernando, Moreno, Isabel, Petäjä, Tuukka, Artaxo, Paulo, Laj, Paolo, Hansel, Armin, Carbone, Samara, Kulmala, Markku, Andrade, Marcos, Worsnop, Douglas, Mohr, Claudia, and Bianchi, Federico

Subjects
Physics - Atmospheric and Oceanic Physics, Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

New particle formation (NPF) in the tropical free troposphere (FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules (OOMs) produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in-situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 meters above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4-5 carbon atoms, simultaneously in both gas and particulate phases in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to the growth of newly formed particles, and are potentially crucial for new particle formation in the tropical free troposphere on a continental scale. Our study will thus improve the understanding of aerosol formation process in the tropics.

Published
2023

20. Increasing contribution of nighttime nitrogen chemistry to wintertime haze formation in Beijing observed during COVID-19 lockdowns

Author

Yan, Chao, Tham, Yee Jun, Nie, Wei, Xia, Men, Wang, Haichao, Guo, Yishuo, Ma, Wei, Zhan, Junlei, Hua, Chenjie, Li, Yuanyuan, Deng, Chenjuan, Li, Yiran, Zheng, Feixue, Chen, Xin, Li, Qinyi, Zhang, Gen, Mahajan, Anoop S., Cuevas, Carlos A., Huang, Dan Dan, Wang, Zhe, Sun, Yele, Saiz-Lopez, Alfonso, Bianchi, Federico, Kerminen, Veli-Matti, Worsnop, Douglas R., Donahue, Neil M., Jiang, Jingkun, Liu, Yongchun, Ding, Aijun, and Kulmala, Markku

Published
2023
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21. Atmospheric new particle formation from the CERN CLOUD experiment

Author

Kirkby, Jasper, Amorim, António, Baltensperger, Urs, Carslaw, Kenneth S., Christoudias, Theodoros, Curtius, Joachim, Donahue, Neil M., Haddad, Imad El, Flagan, Richard C., Gordon, Hamish, Hansel, Armin, Harder, Hartwig, Junninen, Heikki, Kulmala, Markku, Kürten, Andreas, Laaksonen, Ari, Lehtipalo, Katrianne, Lelieveld, Jos, Möhler, Ottmar, Riipinen, Ilona, Stratmann, Frank, Tomé, Antonio, Virtanen, Annele, Volkamer, Rainer, Winkler, Paul M., and Worsnop, Douglas R.

Published
2023
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22. The missing base molecules in atmospheric acid–base nucleation

Author

Cai, Runlong, Yin, Rujing, Yan, Chao, Yang, Dongsen, Deng, Chenjuan, Dada, Lubna, Kangasluoma, Juha, Kontkanen, Jenni, Halonen, Roope, Ma, Yan, Zhang, Xiuhui, Paasonen, Pauli, Petäjä, Tuukka, Kerminen, Veli-Matti, Liu, Yongchun, Bianchi, Federico, Zheng, Jun, Wang, Lin, Hao, Jiming, Smith, James N, Donahue, Neil M, Kulmala, Markku, Worsnop, Douglas R, and Jiang, Jingkun

Subjects
Earth Sciences, Atmospheric Sciences, Climate Action, new particle formation, acid-base nucleation, aerosol, polluted urban environment, Crop and Pasture Production
Abstract

Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration, cloud formation and hence the climate. The clustering of acid and base molecules is a major mechanism driving fast nucleation and initial growth of new particles in the atmosphere. However, the acid-base cluster composition, measured using state-of-the-art mass spectrometers, cannot explain the measured high formation rate of new particles. Here we present strong evidence for the existence of base molecules such as amines in the smallest atmospheric sulfuric acid clusters prior to their detection by mass spectrometers. We demonstrate that forming (H2SO4)1(amine)1 is the rate-limiting step in atmospheric H2SO4-amine nucleation and the uptake of (H2SO4)1(amine)1 is a major pathway for the initial growth of H2SO4 clusters. The proposed mechanism is very consistent with measured new particle formation in urban Beijing, in which dimethylamine is the key base for H2SO4 nucleation while other bases such as ammonia may contribute to the growth of larger clusters. Our findings further underline the fact that strong amines, even at low concentrations and when undetected in the smallest clusters, can be crucial to particle formation in the planetary boundary layer.

Published
2022

26. Measurements of aerosol microphysical and chemical properties in the central Arctic atmosphere during MOSAiC

Author

Heutte, Benjamin, Bergner, Nora, Beck, Ivo, Angot, Hélène, Dada, Lubna, Quéléver, Lauriane L. J., Laurila, Tiia, Boyer, Matthew, Brasseur, Zoé, Daellenbach, Kaspar R., Henning, Silvia, Kuang, Chongai, Kulmala, Markku, Lampilahti, Janne, Lampimäki, Markus, Petäjä, Tuukka, Shupe, Matthew D., Sipilä, Mikko, Uin, Janek, Jokinen, Tuija, and Schmale, Julia

Published
2023
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34. Widespread detection of chlorine oxyacids in the Arctic atmosphere

Author

Tham, Yee Jun, Sarnela, Nina, Iyer, Siddharth, Li, Qinyi, Angot, Hélène, Quéléver, Lauriane L. J., Beck, Ivo, Laurila, Tiia, Beck, Lisa J., Boyer, Matthew, Carmona-García, Javier, Borrego-Sánchez, Ana, Roca-Sanjuán, Daniel, Peräkylä, Otso, Thakur, Roseline C., He, Xu-Cheng, Zha, Qiaozhi, Howard, Dean, Blomquist, Byron, Archer, Stephen D., Bariteau, Ludovic, Posman, Kevin, Hueber, Jacques, Helmig, Detlev, Jacobi, Hans-Werner, Junninen, Heikki, Kulmala, Markku, Mahajan, Anoop S., Massling, Andreas, Skov, Henrik, Sipilä, Mikko, Francisco, Joseph S., Schmale, Julia, Jokinen, Tuija, and Saiz-Lopez, Alfonso

Published
2023
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35. The impact of the atmospheric turbulence development tendency on new particle formation: a common finding on three continents

Author

Wu, Hao, Li, Zhanqing, Li, Hanqing, Luo, Kun, Wang, Yuying, Yan, Peng, Hu, Fei, Zhang, Fang, Sun, Yele, Shang, Dongjie, Liang, Chunsheng, Zhang, Dongmei, Wei, Jing, Wu, Tong, Jin, Xiaoai, Fan, Xinxin, Cribb, Maureen, Fischer, Marc L, Kulmala, Markku, and Petäjä, Tuukka

Subjects
Earth Sciences, Atmospheric Sciences, molecular dynamic, new particle formation, turbulence development, Crop and Pasture Production
Abstract

A new mechanism of new particle formation (NPF) is investigated using comprehensive measurements of aerosol physicochemical quantities and meteorological variables made in three continents, including Beijing, China; the Southern Great Plains site in the USA; and SMEAR II Station in Hyytiälä, Finland. Despite the considerably different emissions of chemical species among the sites, a common relationship was found between the characteristics of NPF and the stability intensity. The stability parameter (ζ = Z/L, where Z is the height above ground and L is the Monin-Obukhov length) is found to play an important role; it drops significantly before NPF as the atmosphere becomes more unstable, which may serve as an indicator of nucleation bursts. As the atmosphere becomes unstable, the NPF duration is closely related to the tendency for turbulence development, which influences the evolution of the condensation sink. Presumably, the unstable atmosphere may dilute pre-existing particles, effectively reducing the condensation sink, especially at coarse mode to foster nucleation. This new mechanism is confirmed by model simulations using a molecular dynamic model that mimics the impact of turbulence development on nucleation by inducing and intensifying homogeneous nucleation events.

Published
2021

38. Assessing Human Exposure to SVOCs in Materials, Products, and Articles: A Modular Mechanistic Framework

Author

Eichler, Clara MA, Hubal, Elaine A Cohen, Xu, Ying, Cao, Jianping, Bi, Chenyang, Weschler, Charles J, Salthammer, Tunga, Morrison, Glenn C, Koivisto, Antti Joonas, Zhang, Yinping, Mandin, Corinne, Wei, Wenjuan, Blondeau, Patrice, Poppendieck, Dustin, Liu, Xiaoyu, Delmaar, Christiaan JE, Fantke, Peter, Jolliet, Olivier, Shin, Hyeong-Moo, Diamond, Miriam L, Shiraiwa, Manabu, Zuend, Andreas, Hopke, Philip K, von Goetz, Natalie, Kulmala, Markku, and Little, John C

Subjects
Prevention, 2.2 Factors relating to the physical environment, Aetiology, Air Pollutants, Air Pollution, Indoor, Dust, Humans, Organic Chemicals, Volatile Organic Compounds, Environmental Sciences
Abstract

A critical review of the current state of knowledge of chemical emissions from indoor sources, partitioning among indoor compartments, and the ensuing indoor exposure leads to a proposal for a modular mechanistic framework for predicting human exposure to semivolatile organic compounds (SVOCs). Mechanistically consistent source emission categories include solid, soft, frequent contact, applied, sprayed, and high temperature sources. Environmental compartments are the gas phase, airborne particles, settled dust, indoor surfaces, and clothing. Identified research needs are the development of dynamic emission models for several of the source emission categories and of estimation strategies for critical model parameters. The modular structure of the framework facilitates subsequent inclusion of new knowledge, other chemical classes of indoor pollutants, and additional mechanistic processes relevant to human exposure indoors. The framework may serve as the foundation for developing an open-source community model to better support collaborative research and improve access for application by stakeholders. Combining exposure estimates derived using this framework with toxicity data for different end points and toxicokinetic mechanisms will accelerate chemical risk prioritization, advance effective chemical management decisions, and protect public health.

Published
2021

39. Aerosol-boundary-layer-monsoon interactions amplify semi-direct effect of biomass smoke on low cloud formation in Southeast Asia

Author

Ding, Ke, Huang, Xin, Ding, Aijun, Wang, Minghuai, Su, Hang, Kerminen, Veli-Matti, Petäjä, Tuukka, Tan, Zhemin, Wang, Zilin, Zhou, Derong, Sun, Jianning, Liao, Hong, Wang, Huijun, Carslaw, Ken, Wood, Robert, Zuidema, Paquita, Rosenfeld, Daniel, Kulmala, Markku, Fu, Congbin, Pöschl, Ulrich, Cheng, Yafang, and Andreae, Meinrat O

Subjects
Climate Action
Abstract

Low clouds play a key role in the Earth-atmosphere energy balance and influence agricultural production and solar-power generation. Smoke aloft has been found to enhance marine stratocumulus through aerosol-cloud interactions, but its role in regions with strong human activities and complex monsoon circulation remains unclear. Here we show that biomass burning aerosols aloft strongly increase the low cloud coverage over both land and ocean in subtropical southeastern Asia. The degree of this enhancement and its spatial extent are comparable to that in the Southeast Atlantic, even though the total biomass burning emissions in Southeast Asia are only one-fifth of those in Southern Africa. We find that a synergetic effect of aerosol-cloud-boundary layer interaction with the monsoon is the main reason for the strong semi-direct effect and enhanced low cloud formation in southeastern Asia.

Published
2021

40. Size-dependent influence of NOx on the growth rates of organic aerosol particles

Author

Yan, C, Nie, W, Vogel, AL, Dada, L, Lehtipalo, K, Stolzenburg, D, Wagner, R, Rissanen, MP, Xiao, M, Ahonen, L, Fischer, L, Rose, C, Bianchi, F, Gordon, H, Simon, M, Heinritzi, M, Garmash, O, Roldin, P, Dias, A, Ye, P, Hofbauer, V, Amorim, A, Bauer, PS, Bergen, A, Bernhammer, A-K, Breitenlechner, M, Brilke, S, Buchholz, A, Mazon, S Buenrostro, Canagaratna, MR, Chen, X, Ding, A, Dommen, J, Draper, DC, Duplissy, J, Frege, C, Heyn, C, Guida, R, Hakala, J, Heikkinen, L, Hoyle, CR, Jokinen, T, Kangasluoma, J, Kirkby, J, Kontkanen, J, Kürten, A, Lawler, MJ, Mai, H, Mathot, S, Mauldin, RL, Molteni, U, Nichman, L, Nieminen, T, Nowak, J, Ojdanic, A, Onnela, A, Pajunoja, A, Petäjä, T, Piel, F, Quéléver, LLJ, Sarnela, N, Schallhart, S, Sengupta, K, Sipilä, M, Tomé, A, Tröstl, J, Väisänen, O, Wagner, AC, Ylisirniö, A, Zha, Q, Baltensperger, U, Carslaw, KS, Curtius, J, Flagan, RC, Hansel, A, Riipinen, I, Smith, JN, Virtanen, A, Winkler, PM, Donahue, NM, Kerminen, V-M, Kulmala, M, Ehn, M, and Worsnop, DR

Subjects
Climate Action
Abstract

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Published
2020

41. The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source

Author

Finkenzeller, Henning, Iyer, Siddharth, He, Xu-Cheng, Simon, Mario, Koenig, Theodore K., Lee, Christopher F., Valiev, Rashid, Hofbauer, Victoria, Amorim, Antonio, Baalbaki, Rima, Baccarini, Andrea, Beck, Lisa, Bell, David M., Caudillo, Lucía, Chen, Dexian, Chiu, Randall, Chu, Biwu, Dada, Lubna, Duplissy, Jonathan, Heinritzi, Martin, Kemppainen, Deniz, Kim, Changhyuk, Krechmer, Jordan, Kürten, Andreas, Kvashnin, Alexandr, Lamkaddam, Houssni, Lee, Chuan Ping, Lehtipalo, Katrianne, Li, Zijun, Makhmutov, Vladimir, Manninen, Hanna E., Marie, Guillaume, Marten, Ruby, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Petäjä, Tuukka, Philippov, Maxim, Ranjithkumar, Ananth, Rörup, Birte, Shen, Jiali, Stolzenburg, Dominik, Tauber, Christian, Tham, Yee Jun, Tomé, António, Vazquez-Pufleau, Miguel, Wagner, Andrea C., Wang, Dongyu S., Wang, Mingyi, Wang, Yonghong, Weber, Stefan K., Nie, Wei, Wu, Yusheng, Xiao, Mao, Ye, Qing, Zauner-Wieczorek, Marcel, Hansel, Armin, Baltensperger, Urs, Brioude, Jérome, Curtius, Joachim, Donahue, Neil M., Haddad, Imad El, Flagan, Richard C., Kulmala, Markku, Kirkby, Jasper, Sipilä, Mikko, Worsnop, Douglas R., Kurten, Theo, Rissanen, Matti, and Volkamer, Rainer

Published
2023
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42. 'Forced to Think'--An Analysis of How Students Benefit from Online Warm-Up Exercises with Feedback

Author

Kulmala, Kimmo, Kokkonen, Tommi, and Kontro, Inkeri

Abstract

Active learning yields better learning outcomes than traditional, lecture-based teaching. Common approaches in large lecture courses are activating elements during the lectures and warm-up activities using online learning environments. However, implementing warm-up exercises, on which students work on by themselves makes formative feedback increasingly important. We have studied students' views on warm-up online exercises, focusing on the role of automated feedback. We compared two types of feedback: feedback which guided the student towards the correct answer and feedback that guided the student towards the correct reading materials. We have also examined the correlation between students' views on the exercises and learning outcomes, as measured by exercise and exam points. The exercises were administered with a Moodle-based system focusing on teaching and assessment using a computer-based algebra kernel. The study was conducted during the first introductory mechanics course in physics at the University of Helsinki. We concluded that the preferred type of feedback was dependent on the student, i.e. different students prefer different kinds of feedback. Importantly, the students who completed the exercises alone reported benefiting more from them, which shows that the warm-up exercises successfully extended support for students outside of classroom hours.

Published
2021
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43. Synergistic HNO3–H2SO4–NH3 upper tropospheric particle formation

Author

Wang, Mingyi, Xiao, Mao, Bertozzi, Barbara, Marie, Guillaume, Rörup, Birte, Schulze, Benjamin, Bardakov, Roman, He, Xu-Cheng, Shen, Jiali, Scholz, Wiebke, Marten, Ruby, Dada, Lubna, Baalbaki, Rima, Lopez, Brandon, Lamkaddam, Houssni, Manninen, Hanna E., Amorim, António, Ataei, Farnoush, Bogert, Pia, Brasseur, Zoé, Caudillo, Lucía, De Menezes, Louis-Philippe, Duplissy, Jonathan, Ekman, Annica M. L., Finkenzeller, Henning, Carracedo, Loïc Gonzalez, Granzin, Manuel, Guida, Roberto, Heinritzi, Martin, Hofbauer, Victoria, Höhler, Kristina, Korhonen, Kimmo, Krechmer, Jordan E., Kürten, Andreas, Lehtipalo, Katrianne, Mahfouz, Naser G. A., Makhmutov, Vladimir, Massabò, Dario, Mathot, Serge, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Onnela, Antti, Petäjä, Tuukka, Philippov, Maxim, Piedehierro, Ana A., Pozzer, Andrea, Ranjithkumar, Ananth, Schervish, Meredith, Schobesberger, Siegfried, Simon, Mario, Stozhkov, Yuri, Tomé, António, Umo, Nsikanabasi Silas, Vogel, Franziska, Wagner, Robert, Wang, Dongyu S., Weber, Stefan K., Welti, André, Wu, Yusheng, Zauner-Wieczorek, Marcel, Sipilä, Mikko, Winkler, Paul M., Hansel, Armin, Baltensperger, Urs, Kulmala, Markku, Flagan, Richard C., Curtius, Joachim, Riipinen, Ilona, Gordon, Hamish, Lelieveld, Jos, El-Haddad, Imad, Volkamer, Rainer, Worsnop, Douglas R., Christoudias, Theodoros, Kirkby, Jasper, Möhler, Ottmar, and Donahue, Neil M.

Published
2022
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44. The Effectiveness and Student Perceptions of Peer-Conducted Team-Based Learning Compared to Faculty-Led Teaching in Undergraduate Teaching

Author

Huilaja L, Bur E, Jokelainen J, Sinikumpu SP, and Kulmala P

Subjects
peer teaching, team-based learning, active learning, Special aspects of education, LC8-6691, Medicine (General), R5-920
Abstract

Laura Huilaja,1,&ast; Eeva Bur,2,&ast; Jari Jokelainen,3 Suvi-Päivikki Sinikumpu,1 Petri Kulmala2,4 1Department of Dermatology and Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu and Oulu University Hospital, Oulu, Finland; 2Faculty of Medicine, University of Oulu, Oulu, Finland; 3Infrastructure for Population Studies, Faculty of Medicine, University of Oulu, Oulu, Finland; 4Department of Pediatrics and Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu and Oulu University Hospital, Oulu, Finland&ast;These authors contributed equally to this workCorrespondence: Laura Huilaja, Email laura.huilaja@oulu.fiBackground: Today’s professionals need to be capable of independent information retrieval, teamwork, and lifelong learning. To meet these demands, more active learning methods are needed in university teaching. Team-based learning (TBL) is a learner-centered method which enables activation of students in large classes.Objective: The aim of this study was to compare a method combining peer teaching and TBL (peer-conducted TBL; pTBL) with faculty-led seminar teaching. More precisely, students’ opinions about teaching methods and immediate and long-term learning outcomes were aimed to compare.Methods: A faculty-led design was compared to a pTBL design when teaching pediatric and dermatological allergy in a seminar setting for 5th year medical students. For that purpose, students were randomly split into two learning groups. In a faculty-led seminar (n = 44 students) the instructor first lectured on each subject; then, named students from each group were asked to present clinical cases given to them beforehand and them raising questions were answered. In a pTBL group (n = 50) student’s prior knowledge was first tested. Then, randomly selected, pre-prepared students took a tutors role in a seminar and presented clinical case to be solved in groups by all students. Students’ performance was equally tested after both sessions and 5– 6 months afterwards. Students’ opinions were asked by an electronic survey.Results: In this study, pTBL was significantly preferred over faculty-led learning (mean grade 8.5 vs 6.5). Those participating in pTBL group studied pre-learning material more actively than those in faculty-led group. However, there was no difference in learning outcomes (immediate or long term) between the groups.Conclusion: Students prefer teaching method in which they are self in active role. Combining TBL and peer teaching may further increase the accumulation of non-academic skills like expertise and proficiency.Keywords: peer teaching, team-based learning, active learning

Published
2022

45. An Integrated Research Infrastructure for Validating Cyber-Physical Energy Systems

Author

Strasser, Thomas I., Moyo, Cyndi, Bründlinger, Roland, Lehnhoff, Sebastian, Blank, Marita, Palensky, Peter, van der Meer, Arjen A., Heussen, Kai, Gehrke, Oliver, Rodriguez, J. Emilio, Merino, Julia, Sandroni, Carlo, Verga, Maurizio, Calin, Mihai, Khavari, Ata, Sosnina, Maria, de Jong, Erik, Rohjans, Sebastian, Kulmala, Anna, Mäki, Kari, Brandl, Ron, Coffele, Federico, Burt, Graeme M., Kotsampopoulos, Panos, and Hatziargyriou, Nikos

Subjects
Computer Science - Systems and Control
Abstract

Renewables are key enablers in the plight to reduce greenhouse gas emissions and cope with anthropogenic global warming. The intermittent nature and limited storage capabilities of renewables culminate in new challenges that power system operators have to deal with in order to regulate power quality and ensure security of supply. At the same time, the increased availability of advanced automation and communication technologies provides new opportunities for the derivation of intelligent solutions to tackle the challenges. Previous work has shown various new methods of operating highly interconnected power grids, and their corresponding components, in a more effective way. As a consequence of these developments, the traditional power system is being transformed into a cyber-physical energy system, a smart grid. Previous and ongoing research have tended to mainly focus on how specific aspects of smart grids can be validated, but until there exists no integrated approach for the analysis and evaluation of complex cyber-physical systems configurations. This paper introduces integrated research infrastructure that provides methods and tools for validating smart grid systems in a holistic, cyber-physical manner. The corresponding concepts are currently being developed further in the European project ERIGrid., Comment: 8th International Conference on Industrial Applications of Holonic and Multi-Agent Systems (HoloMAS 2017)

Published
2017
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46. Secondary organic aerosol formed by condensing anthropogenic vapours over China’s megacities

Author

Nie, Wei, Yan, Chao, Huang, Dan Dan, Wang, Zhe, Liu, Yuliang, Qiao, Xiaohui, Guo, Yishuo, Tian, Linhui, Zheng, Penggang, Xu, Zhengning, Li, Yuanyuan, Xu, Zheng, Qi, Ximeng, Sun, Peng, Wang, Jiaping, Zheng, Feixue, Li, Xiaoxiao, Yin, Rujing, Dallenbach, Kaspar R., Bianchi, Federico, Petäjä, Tuukka, Zhang, Yanjun, Wang, Mingyi, Schervish, Meredith, Wang, Sainan, Qiao, Liping, Wang, Qian, Zhou, Min, Wang, Hongli, Yu, Chuan, Yao, Dawen, Guo, Hai, Ye, Penglin, Lee, Shuncheng, Li, Yong Jie, Liu, Yongchun, Chi, Xuguang, Kerminen, Veli-Matti, Ehn, Mikael, Donahue, Neil M., Wang, Tao, Huang, Cheng, Kulmala, Markku, Worsnop, Douglas, Jiang, Jingkun, and Ding, Aijun

Published
2022
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48. Rapid growth of organic aerosol nanoparticles over a wide tropospheric temperature range

Author

Stolzenburg, Dominik, Fischer, Lukas, Vogel, Alexander L, Heinritzi, Martin, Schervish, Meredith, Simon, Mario, Wagner, Andrea C, Dada, Lubna, Ahonen, Lauri R, Amorim, Antonio, Baccarini, Andrea, Bauer, Paulus S, Baumgartner, Bernhard, Bergen, Anton, Bianchi, Federico, Breitenlechner, Martin, Brilke, Sophia, Mazon, Stephany Buenrostro, Chen, Dexian, Dias, António, Draper, Danielle C, Duplissy, Jonathan, Haddad, Imad El, Finkenzeller, Henning, Frege, Carla, Fuchs, Claudia, Garmash, Olga, Gordon, Hamish, He, Xucheng, Helm, Johanna, Hofbauer, Victoria, Hoyle, Christopher R, Kim, Changhyuk, Kirkby, Jasper, Kontkanen, Jenni, Kürten, Andreas, Lampilahti, Janne, Lawler, Michael, Lehtipalo, Katrianne, Leiminger, Markus, Mai, Huajun, Mathot, Serge, Mentler, Bernhard, Molteni, Ugo, Nie, Wei, Nieminen, Tuomo, Nowak, John B, Ojdanic, Andrea, Onnela, Antti, Passananti, Monica, Petäjä, Tuukka, Quéléver, Lauriane LJ, Rissanen, Matti P, Sarnela, Nina, Schallhart, Simon, Tauber, Christian, Tomé, António, Wagner, Robert, Wang, Mingyi, Weitz, Lena, Wimmer, Daniela, Xiao, Mao, Yan, Chao, Ye, Penglin, Zha, Qiaozhi, Baltensperger, Urs, Curtius, Joachim, Dommen, Josef, Flagan, Richard C, Kulmala, Markku, Smith, James N, Worsnop, Douglas R, Hansel, Armin, Donahue, Neil M, and Winkler, Paul M

Subjects
aerosols, nanoparticle growth, aerosol formation, CLOUD experiment, volatile organic compounds
Abstract

Nucleation and growth of aerosol particles from atmospheric vapors constitutes a major source of global cloud condensation nuclei (CCN). The fraction of newly formed particles that reaches CCN sizes is highly sensitive to particle growth rates, especially for particle sizes

Published
2018

50. Terpene emissions from boreal wetlands can initiate stronger atmospheric new particle formation than boreal forests

Author

Junninen, Heikki, Ahonen, Lauri, Bianchi, Federico, Quéléver, Lauriane, Schallhart, Simon, Dada, Lubna, Manninen, Hanna Elina, Leino, Katri, Lampilahti, Janne, Buenrostro Mazon, Stephany, Rantala, Pekka, Räty, Mari, Kontkanen, Jenni, Negri, Sara, Aliaga, Diego, Garmash, Olga, Alekseychik, Pavel, Lipp, Helina, Tamme, Kalju, Levula, Janne, Sipilä, Mikko, Ehn, Mikael, Worsnop, Douglas, Zilitinkevich, Sergej, Mammarella, Ivan, Rinne, Janne, Vesala, Timo, Petäjä, Tuukka, Kerminen, Veli-Matti, and Kulmala, Markku

Published
2022
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