| 1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
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- 2019
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Journal article (peer-reviewed)
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| 4. |
- Zhao, Sen, et al.
(author)
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Expanding the mutation and phenotype spectrum of MYH3-associated skeletal disorders
- 2022
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In: NPJ genomic medicine. - : Nature Publishing Group. - 2056-7944. ; 7:1
-
Journal article (peer-reviewed)abstract
- Pathogenic variants in MYH3 cause distal arthrogryposis type 2A and type 2B3 as well as contractures, pterygia and spondylocarpotarsal fusion syndromes types 1A and 1B. These disorders are ultra-rare and their natural course and phenotypic variability are not well described. In this study, we summarize the clinical features and genetic findings of 17 patients from 10 unrelated families with vertebral malformations caused by dominant or recessive pathogenic variants in MYH3. Twelve novel pathogenic variants in MYH3 (NM_002470.4) were identified: three of them were de novo or inherited in autosomal dominant way and nine were inherited in autosomal recessive way. The patients had vertebral segmentation anomalies accompanied with variable joint contractures, short stature and dysmorphic facial features. There was a significant phenotypic overlap between dominant and recessive MYH3-associated conditions regarding the degree of short stature as well as the number of vertebral fusions. All monoallelic variants caused significantly decreased SMAD3 phosphorylation, which is consistent with the previously proposed pathogenic mechanism of impaired canonical TGF-β signaling. Most of the biallelic variants were predicted to be protein-truncating, while one missense variant c.4244T>G,p.(Leu1415Arg), which was inherited in an autosomal recessive way, was found to alter the phosphorylation level of p38, suggesting an inhibition of the non-canonical pathway of TGF-β signaling. In conclusion, the identification of 12 novel pathogenic variants and overlapping phenotypes in 17 affected individuals from 10 unrelated families expands the mutation and phenotype spectrum of MYH3-associated skeletal disorders. We show that disturbances of canonical or non-canonical TGF-β signaling pathways are involved in pathogenesis of MYH3-associated skeletal fusion (MASF) syndrome.
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| 5. |
- Becker, Richard C., et al.
(author)
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Chromogenic laboratory assays to measure the factor Xa-inhibiting properties of apixaban-an oral, direct and selective factor Xa inhibitor
- 2011
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In: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 32:2, s. 183-187
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Journal article (peer-reviewed)abstract
- An ability to readily determine an anticoagulant effect with an emerging class of direct, active site, oral factor Xa inhibitors is viewed by the medical community as attractive and by some as an absolute requirement for their use in clinical practice. We performed a pharmacokinetic and pharmacodynamic substudy in APPRAISE-1-a study of apixaban in patients with acute coronary syndrome(ACS). A total of 1691 patients had blood sampled for apixaban plasma concentrations using mass spectrometry/high performance liquid chromatography and anti-Xa activity using a chromogenic assay employing either low molecular weight heparin or apixaban as reference standards. Anti-Xa activity, determined by either anti-Xa-LMWH (r = 0.9671; P < 0.0001) or anti-Xa-apixaban (r = 0.9669; P < 0.0001) correlated strongly and in a linear fashion with apixaban plasma concentrations. The correlations for each method were equally strong at low (< 100 ng/ml) (r = 0.86, P < 0.0001; r = 0.85, P < 0.0001), intermediate(100-200 ng/ml) (r = 0.73, P < 0.0001; r = 0.69, P < 0.0001) and high (> 200 ng/ml) (r = 0.91, P < 0.0001; r = 0.91, P < 0.0001) plasma concentrations of apixaban, respectively. Our pharmacokinetic and pharmacodynamic substudy suggests that an apixaban-mediated anticoagulant effect can be detected even at very low plasma concentrations using a standard laboratory chromogenic anti-Xa assay with either LMWH or apixaban calibrators. While establishing parameters for safety and efficacy will require further investigation, an ability to discern the presence of a drug effect may provide clinically useful information.
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| 6. |
- Becker, Richard C., et al.
(author)
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Effect of apixaban, an oral and direct factor Xa inhibitor, on coagulation activity biomarkers following acute coronary syndrome
- 2010
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In: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 104:5, s. 976-983
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Journal article (peer-reviewed)abstract
- Apixaban is an oral, direct factor Xa inhibitor under development for secondary prevention in acute coronary syndrome (ACS) Apixaban's effect on D dimer and prothrombin fragment 12 (F1 2) (coagulation activity biomarkers) was determined in a randomised, double blinded, placebo controlled phase 2 study Patients (n=1,715) with either ST segment elevation or non ST segment elevation ACS received either placebo or apixaban 2 5 mg twice daily 10 mg once daily, 10 mg twice daily or 20 mg once daily for six months Samples were obtained at baseline (before study drug administration), week 3 and week 26 Apixaban plasma concentrations were measured directly by liquid chromatography/mass spectometry and anti Xa activity was determined using apixaban as a reference standard D dimer and F 1 2 were measured using ELISA based methods Most patients had elevated D dimer and Fl 2 levels at baseline Both coagulation activity biomarkers decreased by week 3 in all treatment groups but to a greater degree with apixaban than placebo (p<0 001) In a multivariable analysis, apixaban was independently associated with a change in biomarkers over time (p<0 0001) While the overall decrease did not differ significantly among the three highest apixaban doses, Fl 2 was suppressed more rapidly by the 10 mg once daily than the 2 5 mg twice daily dose (p<0 05) There was a strong and direct relationship between apixaban plasma concentrations and anti Xa apixaban levels, and an inverse relationship for both measures with coagulation activity biomarkers In conclusion the oral direct factor Xa inhibitor apixaban significantly reduced coagulation activity biomarkers among patients with ACS The 10 mg once daily dose reduced thrombin generation (F 1 2) and fibrin formation (D dimer) more rapidly and robustly than the 25 mg twice daily dose The effect on both D dimer and F 12 was apixaban concentration and factor Xa inhibition dependent durable and provided general guidance for dose selection in phase 3 investigation.
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| 7. |
- Bournas, Iason, et al.
(author)
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Energy efficient and moisture safe row houses in Sweden
- 2015
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In: Proceedings of the 31st PLEA conference.
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Conference paper (peer-reviewed)abstract
- This project consists of a thorough study of an energy efficient and moisture safe row-house, located in the Nordic climate of Sweden. Climate and site analysis, building scale design decisions and finally the evaluation and optimization of its energy performance were different steps of a holistic process aiming at the architectural quality, energy efficiency, comfort and the well-being of users. The final house design is addressing the spatial requirements of the on-going population increase, that is imminent in the developing countries, but while doing so, it exerts minimum impact on environmental resources and avoids ecological damage. The passive house standards had to be reached by applying passive heating strategies to reduce the heating demand. Increasing thermal insulation thickness and thermal mass elements in the house had a significant role in reducing heat loss and keeping the house warm in winter nights. Other passive house standards, U-values of envelope elements as well as the window-to-wall area played an important role. The moisture risks had to be avoided and the wooden construction proved to function well under the climatic conditions. An innovative method of timing the shading and nighttime natural ventilation was included as a passive strategy for natural cooling. Time period, position and type of shading was optimized according to hourly data and the correlation of internal and solar gains, and their impact on the operative temperature. To ensure summer wind cooling, the interior spatial distribution and circulation areas were designed to exploit the stack effect and cross ventilation by the opening of specific windows. A water retention technique was achieved by coupling recirculated hot water with electrical water heater. The overall energy intensity would finally be assessed and further minimized by the use of an active photovoltaic system on the roof, to exploit the renewable energy of the sun.
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| 8. |
- Cao, Qi, et al.
(author)
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Jointly estimating the most likely driving paths and destination locations with incomplete vehicular trajectory data
- 2023
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In: Transportation Research, Part C: Emerging Technologies. - 0968-090X. ; 155
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Journal article (peer-reviewed)abstract
- With an ever-increasing deployment density of probe and fixed sensors, massive vehicular trajectory data is available and show a promising foundation to improve the observability of dynamic traffic demand pattern. However, due to technical and privacy issues, the raw trajectories are not always complete and the paths and destinations between discontinuous trajectory nodes are usually missing. This paper proposes a probabilistic method to jointly reconstruct the missing driving path and destination location of vehicles with incomplete trajectory data. One problem-specific HMM-structured model incorporating spatial and temporal analysis (ST-HMM) is constructed to define the matching probability between observed data and possible movement. Two algorithms, namely candidate set generation and best-match search algorithms, are developed to seek the most possible one as matching result. It can implement end-to-end processing from incomplete trajectory data to complete and connective paths and destinations for the target vehicle. The proposed method is tested based on field-test data and city-wide road network. Compared with two benchmark methods, the proposed method improved the matching accuracy in terms of both path identification and destination inference. Additionally, sensitivity analyses on the size of training dataset and candidate set were performed. We believe that experiment results of these sensitivity analyses can help to provide guidance on data sensing and candidate generation.
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| 9. |
- Han, Hedong, et al.
(author)
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Utilization of Palliative Care for Patients Undergoing Hematopoietic Stem Cell Transplantation During Hospitalization : A Population-Based National Study
- 2019
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In: The American Journal of Hospice and Palliative Medicine. - : Sage Publications. - 1049-9091 .- 1938-2715. ; 36:10, s. 900-906
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Patients undergoing hematopoietic stem cell transplantation (HSCT) have substantial physical and psychological symptoms. This study aimed to investigate the utilization of palliative care (PC) in patients undergoing HSCT during hospitalization.METHODS: The 2008-2014 National Inpatient Sample was queried for eligible participants. Demographics, hospital characteristics, comorbidities, posttransplantation complications, and inpatient procedures were compared between patients with and without PC. Multivariate logistic regression was performed to identify predictors associated with PC use.RESULTS: Among 21 458 patients undergoing HSCT during hospitalization, 278 (1.30%) received PC. The rate of PC use has significantly increased from 0.64% in 2008 to 1.95% in 2014. Patients receiving PC had more co-comorbidities, posttransplantation complications, inpatient procedures, and were more likely to carry a diagnosis of leukemia. In allogeneic HSCT, large bed size (odds ratio [OR] =2.80; 95% confidence interval [CI]: 1.17-6.70), stem cell source from cord blood (OR = 1.93; 95% CI: 1.15-3.24), and graft-versus-host disease (OR = 2.04; 95% CI: 1.36-3.06) were predictors of PC use. In a subset analysis of 783 patients who died during hospitalization, 166 (21.20%) received PC. Among the decedents, Hispanic race had lower odds of PC use (OR = 0.20; 95% CI: 0.05-0.82) in allogeneic HSCT and women had higher odds of PC (OR = 2.70; 95% CI: 1.35-5.41) in autologous HSCT.CONCLUSIONS: The rate of PC use has significantly increased among patients undergoing HSCT during hospitalization from 2008 to 2014 but still remains very low. Further investigation is warranted to verify and better understand the barriers toward PC use for HSCT patients.
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| 10. |
- Javanroodi, Kavan, 1988, et al.
(author)
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Optimization of building form and its fenestration in response to microclimate conditions of an urban area
- 2020
-
In: E3S Web of Conferences. - : EDP Sciences. - 2555-0403 .- 2267-1242. ; 172
-
Conference paper (peer-reviewed)abstract
- Designing building form in urban areas is a complicated process that demands considering a high number of influencing parameters. On the other hand, there has been an increasing trend to design highly fenestrated building envelopes for office buildings to induce higher levels of natural lighting into the workspace. This paper presents a novel optimization framework to design high-performance building form and fenestration configuration considering the impacts of urban microclimate in typical and extreme weather conditions during a thirty-year period of climate data (2010-2039). In this regard, based on the introduced technique and algorithm, the annual energy demand and thermal comfort of over 8008 eligible form combinations with eight different fenestration configurations and seven different building orientation angels were analysed in a detailed urban area to find optimal design solutions in response to microclimate conditions. Results showed that adopting the framework, annual heating, and cooling demand can be reduced by 21% and 38% while maintaining thermal comfort by taking design-based decisions at the early stages of design.
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| 11. |
- Jiang, Xiaoqing, et al.
(author)
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High-Performance Regular Perovskite Solar Cells Employing Low-Cost Poly(ethylenedioxythiophene) as a Hole-Transporting Material
- 2017
-
In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
-
Journal article (peer-reviewed)abstract
- Herein, we successfully applied a facile in-situ solid-state synthesis of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a HTM, directly on top of the perovskite layer, in conventional mesoscopic perovskite solar cells (PSCs) (n-i-p structure). The fabrication of the PEDOT film only involved a very simple in-situ solid-state polymerisation step from a monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) made from a commercially available and cheap starting material. The ultraviolet photoelectron spectroscopy (UPS) demonstrated that the as-prepared PEDOT film possesses the highest occupied molecular orbital (HOMO) energy level of -5.5 eV, which facilitates an effective hole extraction from the perovskite absorber as confirmed by the photoluminescence measurements. Optimised PSC devices employing this polymeric HTM in combination with a low-cost vacuum-free carbon cathode (replacing the gold), show an excellent power conversion efficiency (PCE) of 17.0% measured at 100 mW cm(-2) illumination (AM 1.5G), with an open-circuit voltage (V-oc) of 1.05 V, a short-circuit current density (J(sc)) of 23.5 mA/cm(2) and a fill factor (FF) of 0.69, respectively. The present finding highlights the potential application of PEDOT made from solid-state polymerisation as a HTM for cost-effective and highly efficient PSCs.
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| 12. |
- Li, Yuchen, et al.
(author)
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Associations of parental and perinatal factors with subsequent risk of stress-related disorders : a nationwide cohort study with sibling comparison
- 2022
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In: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 27, s. 1712-1719
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Journal article (peer-reviewed)abstract
- Little is known about the contribution of pregnancy-related parental and perinatal factors to the development of stress-related disorders. We aimed to investigate whether parental/perinatal adversities entail higher risks of stress-related disorders in the offspring, later in life, by accounting for genetic and early environmental factors. Based on the nationwide Swedish registers, we conducted a population-based cohort study of 3,435,747 singleton births (of which 2,554,235 were full siblings), born 1973-2008 and survived through the age of 5 years. Using both population- and sibling designs, we employed Cox regression to assess the association between parental and perinatal factors with subsequent risk of stress-related disorders. We identified 55,511 individuals diagnosed with stress-related disorders in the population analysis and 37,433 in the sibling analysis. In the population-based analysis we observed increased risks of stress-related disorders among offspring of maternal/paternal age <25, single mothers, parity >= 4, mothers with BMI >= 25 or maternal smoking in early pregnancy, gestational diabetes, and offspring born moderately preterm (GA 32-36 weeks), or small-for-gestational-age. These associations were significantly attenuated toward null in the sibling analysis. Cesarean-section was weakly associated with offspring stress-related disorders in population [hazard ratio (HR) 1.09, 95% confidence interval (CI) 1.06-1.12] and sibling analyses (HR 1.10, 95% CI 1.02-1.20). Our findings suggest that most of the observed associations between parental and perinatal factors and risk of stress-related disorders in the population analysis are driven by shared familial environment or genetics, and underscore the importance of family designs in epidemiological studies on the etiology of psychiatric disorders.
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| 13. |
- Li, Yuchen, et al.
(author)
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Public awareness, emotional reactions and human mobility in response to the COVID-19 outbreak in China : a population-based ecological study
- 2022
-
In: Psychological Medicine. - : Cambridge University Press. - 0033-2917 .- 1469-8978. ; 52:9, s. 1793-1800
-
Journal article (peer-reviewed)abstract
- Background: The outbreak of COVID-19 generated severe emotional reactions, and restricted mobility was a crucial measure to reduce the spread of the virus. This study describes the changes in public emotional reactions and mobility patterns in the Chinese population during the COVID-19 outbreak.Methods: We collected data on public emotional reactions in response to the outbreak through Weibo, the Chinese Twitter, between January 1st and March 31st, 2020. Using anonymized location-tracking information, we analyzed the daily mobility patterns of approximately 90% of Sichuan residents.Results: There were three distinct phases of the emotional and behavioral reactions to the COVID-19 outbreak. The alarm phase (January 19th –26th) was a restriction-free period, characterized by few new daily cases, but enormous public negative emotions (the number of negative comments per Weibo post increased by 246.9 per day, 95%CI: 122.5–371.3), and a substantial increase in self-limiting mobility (from 45.6% to 54.5%, changing by 1.5% per day, 95%CI: 0.7%–2.3%). The epidemic phase (January 27th –February 15th) exhibited rapidly increasing numbers of new daily cases, decreasing expression of negative emotions (a decrease of 27.3 negative comments per post per day, 95%CI: −40.4–−14.2), and a stabilized level of self-limiting mobility. The relief phase (February 16th –March 31st) had a steady decline in new daily cases and decreasing levels of negative emotion and self-limiting mobility.Conclusions: During the COVID-19 outbreak in China, the public’s emotional reaction was strongest before the actual peak of the outbreak and declined thereafter. The change in human mobility patterns occurred before the implementation of restriction orders, suggesting a possible link between emotion and behavior.
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| 14. |
- Nik, Vahid, 1979, et al.
(author)
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Impacts of climate change and its uncertainties on the renewable energy generation and energy demand in urban areas
- 2019
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In: IBPC Proceedings.
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Conference paper (peer-reviewed)abstract
- This work investigates the effects of future climate uncertainties in calculating the heating and cooling demand of buildings and estimating potentials for renewable energy generation (solar PV and wind). The building stock of Lund in Sweden is considered for energy simulations and for future climate, the most recent outputs of RCA4, which is the 4th generation of the Rossby Centre regional climate model (RCM), is used considering several two representative concentration pathways (RCPs) and four global climate models (GCMs). Simulations and assessment are performed for three 30-year time periods, from 2010 until 2099. Through comparing distributions of data sets, it is found that the uncertainty induced by climate models affects the estimation of renewable energy generation more than those induced by time periods. Changes in the heating demand due to climate change and uncertainties are surprisingly low while it is very large for cooling demand. This can be because of having a good quality for buildings on the average, however this should be more investigated for other cities in Sweden.
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| 15. |
- Shang, Yuchen, et al.
(author)
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Enhancement of short/medium-range order and thermal conductivity in ultrahard sp3 amorphous carbon by C70 precursor
- 2023
-
In: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Journal article (peer-reviewed)abstract
- As an advanced amorphous material, sp3 amorphous carbon exhibits exceptional mechanical, thermal and optical properties, but it cannot be synthesized by using traditional processes such as fast cooling liquid carbon and an efficient strategy to tune its structure and properties is thus lacking. Here we show that the structures and physical properties of sp3 amorphous carbon can be modified by changing the concentration of carbon pentagons and hexagons in the fullerene precursor from the topological transition point of view. A highly transparent, nearly pure sp3−hybridized bulk amorphous carbon, which inherits more hexagonal-diamond structural feature, was synthesized from C70 at high pressure and high temperature. This amorphous carbon shows more hexagonal-diamond-like clusters, stronger short/medium-range structural order, and significantly enhanced thermal conductivity (36.3 ± 2.2 W m−1 K−1) and higher hardness (109.8 ± 5.6 GPa) compared to that synthesized from C60. Our work thus provides a valid strategy to modify the microstructure of amorphous solids for desirable properties.
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| 16. |
- Shang, Yuchen, et al.
(author)
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Ultrahard bulk amorphous carbon from collapsed fullerene
- 2021
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In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 599:7886, s. 599-604
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Journal article (peer-reviewed)abstract
- Amorphous materials inherit short- and medium-range order from the corresponding crystal and thus preserve some of its properties while still exhibiting novel properties1,2. Due to its important applications in technology, amorphous carbon with sp2 or mixed sp2–sp3 hybridization has been explored and prepared3,4, but synthesis of bulk amorphous carbon with sp3 concentration close to 100% remains a challenge. Such materials inherit the short-/medium-range order of diamond and should also inherit its superior properties5. Here, we successfully synthesized millimetre-sized samples—with volumes 103–104 times as large as produced in earlier studies—of transparent, nearly pure sp3 amorphous carbon by heating fullerenes at pressures close to the cage collapse boundary. The material synthesized consists of many randomly oriented clusters with diamond-like short-/medium-range order and possesses the highest hardness (101.9 ± 2.3 GPa), elastic modulus (1,182 ± 40 GPa) and thermal conductivity (26.0 ± 1.3 W m−1 K−1) observed in any known amorphous material. It also exhibits optical bandgaps tunable from 1.85 eV to 2.79 eV. These discoveries contribute to our knowledge about advanced amorphous materials and the synthesis of bulk amorphous materials by high-pressure and high-temperature techniques and may enable new applications for amorphous solids.
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| 17. |
- Yang, Yuchen, et al.
(author)
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Assessing the climate change adaptation over four European cities
- 2021
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 2069:1
-
Conference paper (peer-reviewed)abstract
- In recent years, climate change has been widely recognized as a potential problem. The building industry is taking a variety of actions towards sustainable development and climate change mitigation, such as retrofitting buildings. More than mitigation, it is important to account for climate change adaptation and investigate the probable risks and limits for mitigation strategies. For example, one major challenge may become achieving low energy demand without compromising indoor thermal comfort during warm seasons. This work investigates the future energy performance and indoor thermal comfort of four European cities belonging to four different climate zones in Europe; Barcelona, Koln, Brussels, and Copenhagen. An ensemble of future climate scenarios is used, including thirteen climate scenarios considering five different general circulation models (GCM) and three representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5). Through simulating the energy performance of the representative buildings in each city and considering several climate scenarios, this paper provides a comprehensive picture about the energy performance and indoor thermal comfort of the buildings for near-term, medium-term, and long-term climate conditions.
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| 18. |
- Yang, Yuchen, et al.
(author)
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Assessing the impacts of climate change on the german building stock
- 2019
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In: Building Simulation Conference Proceedings. - : IBPSA. - 2522-2708. ; 16, s. 3563-3568
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Conference paper (peer-reviewed)abstract
- This study investigates the impacts of future climate uncertainties in the new generation of future climate data sets according to AR5(5thassessment report of IPCC) on simulating the energy performance of buildings by studying the building stock in Germany (Potsdam). This work is based on two data bases, namely 'Tabula web tool- European building' and 'EPISCOP'. Software IDA ICE was used to make comprehensive energy simulation of buildings. Four different climate models and two representative concentration pathways (RCP 4.5 and RCP 8.5) were used in the assessment. Simulations run for three 30-year periods between 2010 to 2099. Effects of uncertainties induced by RCPs are thoroughly investigated for long time period. Through the comparison of energy simulation results, it is found that due to climate change, heating demand will decrease, however, cooling demand will increase. According to the results, for the second 30-yearperiod, the heating demand decreases by 7% and cooling demand increases by 16%, compared to the first 30-year period. By comparing the distribution of the data sets, it is also found that the uncertainty caused by the climate model has an estimated impact on the future heating (cooling) demand greater than the uncertainty caused by the time period. The change in heating demand due to climate change and uncertainty is relatively low and very large for cooling demand.
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| 19. |
- Yang, Yuchen, et al.
(author)
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Climate change and energy performance of European residential building stocks – A comprehensive impact assessment using climate big data from the coordinated regional climate downscaling experiment
- 2021
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In: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 298
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Journal article (peer-reviewed)abstract
- In recent years, climate change and the corresponding expected extreme weather conditions have been widely recognized as potential problems. The building industry is taking various actions to achieve sustainable development, implement energy conservation strategies, and provide climate change mitigation. In addition to mitigation, it is crucial to adapt to climate change, and to investigate the possible risks and limitations of mitigation strategies. Although the importance of climate change adaptation is well-understood, there are still challenges in understanding and modeling the impacts of climate change, and the consequent risks and extremes. This work provides a comprehensive study of the impacts of climate change on the energy performances and thermal comfort of European residential building stocks. To perform an unbiased assessment and account for climate uncertainties and extreme events, a large set of future climate data was used for a 90-year period (2010–2099). Climate data for 38 European cities in five different climate zones, downscaled by the “RCA4” regional climate model, were synthesized and applied to simulate the respective energy performances of the residential building stocks in the cities. The results suggest that there will be larger needs for cooling buildings in the future and less heating demand; however, there are differences in the variation rates between zones and cities. Discomfort hours will increase notably in cities within cooling-dominated zones, but will not be affected considerably in cities within heating-dominated zones. In addition to long-term changes, climate-induced extremes can considerably affect future energy demands, especially the cooling demand; this may become challenging for both buildings and energy systems.
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| 20. |
- Yang, Yuchen, et al.
(author)
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Climate Change and Renewable Energy Generation in Europe: Long-Term Impact Assessment on Solar and Wind Energy Using High-Resolution Future Climate Data and Considering Climate Uncertainties
- 2022
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In: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 15:1
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Journal article (peer-reviewed)abstract
- Climate change can strongly affect renewable energy production. The state of the art in projecting future renewable energy generation has focused on using regional climate prediction. However, regional climate prediction is characterized by inherent uncertainty due to the complexity of climate models. This work provides a comprehensive study to quantify the impact of climate uncertainties in projecting future renewable energy potential over five climate zones of Europe. Thirteen future climate scenarios, including five global climate models (GCMs) and three representative concentration pathways (RCPs), are downscaled by the RCA4 regional climate model (RCM) over 90 years (2010–2099), divided into three 30-year periods. Solar and wind energy production is projected considering short-/long-term climate variations and uncertainties in seven representative cities (Narvik, Gothenburg, Munich, Antwerp, Salzburg, Valencia, and Athens). The results showed that the uncertainty caused by GCMs has the most substantial impact on projecting renewable energy generation. The variations due to GCM selection can become even larger than long-term climate change variations over time. Climate change uncertainties lead to over 23% and 45% projection differences for solar PV and wind energy potential, respectively. While the signal of climate change in solar radiation is weak between scenarios and over time, wind energy generation is affected by 25%.
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| 21. |
- Yang, Yuchen
(author)
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Climate Change and Residential Energy Use in Europe : Assessing Future Energy Demands and Renewable Generation Potentials
- 2021
-
Licentiate thesis (other academic/artistic)abstract
- In recent years, climate change and the corresponding expected extreme weather conditions have been widelyrecognized as potential problems. The construction industry is taking various actions to achieve sustainabledevelopment, implement energy conservation strategies, and provide climate change mitigation. In addition tomitigation, it is crucial to adapt to climate change, and to investigate the possible risks and limitations of mitigationstrategies. Although the importance of climate change adaptation is well-understood, there are still challenges inunderstanding and modeling the impacts of climate change, and the consequent risks and extremes.This licentiate dissertation aims to assess the impact of climate change on the building energy performance andindoor thermal comfort in 38 major European cities distributed in five difference climate zones. In addition, this studyalso investigates the potential of renewable energy generation considering solar PV and wind energy generations.To do this, an ensemble of multiple future climate scenarios with high temporal and spatial resolutions have beenused in this work, enabling us to account for climate variations and extreme events. A set of future climate big datagenerated by RCA4 regional climate model (RCM) were used. In total, 13 future climate scenarios covering fiveglobal climate models (GCMs) and three representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5)were used for the 90-year span of 2010-2099, divided into three 30-year periods (2010-2039, 2039-2069 and 2069-2099).Results show that extreme long and short-term climate events can cause significant changes in energy demand,particularly peak loads during extreme events. This work provided more insights into the importance of consideringboth long- and short-term variations of climate, including extreme events, when assessing future energy solutionsand the energy performances of building stocks.The availability of fine temporal and spatial resolution climate datais crucial for assessing the plausible energy demands of buildings; however, it is important consider climateuncertainties, multiple scenarios, and extreme climate events.Finally, the database of results for each city andclimate zone allows decision makers and designers to count for future climate uncertainties in the early stages ofbuilding design.
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| 22. |
- Yang, Yuchen, et al.
(author)
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Impact assessment of climate change on the energy performance of the building stocks in four European cities
- 2020
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In: E3S Web of Conferences. - : EDP Sciences. - 2555-0403 .- 2267-1242. ; 172
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Conference paper (peer-reviewed)abstract
- Many cities are striving to develop urban transformation strategies, in order to transit from traditional city to a sustainable city. Improving the energy efficiency of the existing buildings is the key to address climate change mitigation and adaptation. This paper considers different climate scenarios using different series of future climate in four different European cities, namely, Kiruna, Stockholm, Valencia and Madrid. The study adopts the TABULA database to get access to basic construction information. Energy simulation and data analysis using IDA ICE and MATLAB are performed. Based on climate change, an overall retrofitting plan was developed by combining energy-saving retrofit solutions. The results show that in Madrid and Valencia, future heating demand will decrease and cooling demand will increase. In Kiruna and Stockholm, with the increase of the insulation material, the heating demand of the house has decreased, but the cooling demand has shown a downward trend compared with the cases of Madrid and Valencia. The first reason is the introduction of hybrid cooling, and the second is that the average indoor temperature has been maintained at 21 degrees Celsius due to the low outdoor temperature in summer. The findings indicate that in Kiruna, Stockholm, and Madrid it is better to insulate façades to lower the heating demand in winter. In Valencia, it is possible to have relatively low heating and cooling demand without façades insulation as insulated façades require more cooling demand during summer.
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| 23. |
- Yu, Ze, et al.
(author)
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High-efficiency perovskite solar cells employing a conjugated donor-acceptor co-polymer as a hole-transporting material
- 2017
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In: RSC Advances. - : ROYAL SOC CHEMISTRY. - 2046-2069. ; 7:44, s. 27189-27197
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Journal article (peer-reviewed)abstract
- In this work, we have successfully introduced 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) as an efficient p-type dopant for donor-acceptor (D-A) co-polymer poly[2,6-(4,4-bis-(2ethylhexyl)- 4H-cyclopenta[2,1-b; 3,4-b'] dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) as an HTM in mesoscopic perovskite solar cells (PSCs). The bulk conductivity is significantly enhanced by 4 orders of magnitude when PCPDTBT is doped with F4TCNQ (6%, w/w). UV-vis and Fourier transform infrared spectroscopy (FTIR) results indicate the occurrence of p-doping, which results in higher bulk conductivity. The high conductivity leads to an impressive overall efficiency of 15.1%, which is considerably higher than the pristine PCPDTBT based devices (9.2%). The superior performance obtained should be largely attributed to the significant enhancement of the photocurrent density strongly correlated with a more efficient charge collection. This is the highest efficiency reported so far for PCPDTBT-based PSCs. Thus, molecularly p-doping has been demonstrated to be an effective strategy for further improving the performance of a wide range of D-A and other types of polymeric HTMs in PSCs.
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