| 1. |
- Wang, Fang, et al.
(författare)
-
Emerging contaminants: A One Health perspective
- 2024
-
Ingår i: Innovation. - 2666-6758. ; 5
-
Forskningsöversikt (refereegranskat)abstract
- Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.
|
|
| 2. |
- Watts, Anna L., et al.
(författare)
-
Dense matter with eXTP
- 2019
-
Ingår i: Science China Physics, Mechanics & Astronomy. - : Science Press. - 1674-7348 .- 1869-1927. ; 62:2
-
Forskningsöversikt (refereegranskat)abstract
- In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.
|
|
| 3. |
- Liu, Daosheng, et al.
(författare)
-
Investigation on heating aging mechanism of cellulose paper for oil-immersed transformer main insulation
- 2019
-
Ingår i: Proceedings - IEEE International Conference on Dielectric Liquids. - 2153-3733 .- 2153-3725. ; 2019-June:June
-
Konferensbidrag (refereegranskat)abstract
- Power transformer plays a vital role in maintaining reliable and efficient electricity supply. However, in service is increasing and growing older, much and much attention has been paid on their aging condition and life assessment than ever. The aging and degradation of transformer insulation will determine the life-time of its operation. The intensities of these depend on mechanical, thermal and environmental stresses that act on the insulations. Due to the temperature rise, the lifetime of insulation material will be shortened. The accelerated thermal aging method is often adopted to do some evaluation on the oil-paper insulation materials under different temperature for the thermal lifetime model. According to existing aging test, both insulation paper and mineral oil were aged at the same temperature. In this paper, the thermal aging experiments were implemented on the transformer main insulation model made with modified and unmodified insulation paper. The accelerated thermal aging tests were finished, and the superior electric characteristics of the nano-TiO2 and cellulose composition insulation were validated.
|
|
| 4. |
- Liu, Daosheng, et al.
(författare)
-
Suppression Mechanism of TiO 2 for the Partial Discharge of Oil-paper Insulation in Intensive Electric Field
- 2019
-
Ingår i: Proceedings - IEEE International Conference on Dielectric Liquids. - 2153-3733 .- 2153-3725. ; 2019-June
-
Konferensbidrag (refereegranskat)abstract
- With the rapid development of modern HVDC transmission technology, higher insulation properties are put forward on the oil-paper insulation system of the transformer, which determine the transformer service life to a certain extent. Traditional transformer oil-paper insulation is becoming increasingly difficult to meet the demands of insulation system with large capacity and miniaturization at ultra-high voltage level. In order to improve the insulation strength of oil-paper system, the insulation cellulose paper modified by TiO2 nanoparticles of different diameters (5 nm, 10 nm, 20 nm, 30 nm) were prepared, in addition, each of modified cellulose paper has different mass fraction of TiO2 nanoparticles (1%, 3%, 5%, 7% wt.). The partial discharge (PD) detection platform was established, and the partial discharge inception voltage (PDIV) values of the oil-paper insulation system with and without nanoparticles were measured. To investigate the PD characteristics, the PD waveforms and PD frequency spectrums of modified cellulose paper and the unmodified were obtained. The suppression mechanism of TiO2 nanoparticles on PD was explored through scanning electron microscope (SEM) observation. All the experiment results indicate that adding nano-TiO2 is beneficial to enhance the insulation properties of oil-paper insulation, and the optimum diameter and mass fraction of TiO2 nanoparticles to suppress oil-paper PD were obtained.
|
|
| 5. |
- Yan, Zihan, et al.
(författare)
-
Design Eye-Tracking Augmented Reality Headset to Reduce Cognitive Load in Repetitive Parcel Scanning Task
- 2022
-
Ingår i: IEEE Transactions on Human-Machine Systems. - 2168-2291 .- 2168-2305. ; 52:4, s. 578-590
-
Tidskriftsartikel (refereegranskat)abstract
- Repetitive tasks widely exist in applied fields of human-computer interaction. One underestimated example is parcel scanning, which has consistent operation difficulty but comprises multiple processes (e.g., label seeking and scanning, result confirming, and parcel relocating), involving respective cognitive requirements. Many devices are developed to facilitate repetitive operations, but few are to reduce fluctuating cognitive load throughout task processes. We present the eye-tracking augmented reality headset that integrates foveated vision detection and smooth pursuit of eye tracking and investigate how it can reduce cognitive load in the repetitive task. In total, 33 participants completed a set of parcel scanning tasks with the headset and their visual and cognitive performance were assessed. The results show that the headset maintained high scanning efficiency and lower cognitive load across the tasks with varying difficulties and it significantly reduced the participants' cognitive load during the processes of barcode seeking and scanning and result confirmation. The headset demonstrated good usability and ease of use. Implications for how the case study result could be used in generalizing applications are discussed.
|
|
| 6. |
- Yuan, Chao, et al.
(författare)
-
Space charge behavior in silicone rubber from in-service aged HVDC composite insulators
- 2019
-
Ingår i: IEEE Transactions on Dielectrics and Electrical Insulation. - 1558-4135 .- 1070-9878. ; 26:3, s. 843-850
-
Tidskriftsartikel (refereegranskat)abstract
- Space charge behavior in sheds removed from service aged 500 and 800 kV HVDC silicone rubber insulators and compared to a stored reference insulator is reported in this paper. The aim of this investigation is to evaluate the material aging. The investigations are made under electric field of ±20 kV/mm at room temperature using pulsed electro-acoustic technique. Based on the results, the electric field distribution and mobility of charge carriers, considering the contributions of de-trapping process from both shallow and deep traps, are deduced. It is concluded that space charge concentration in the aged material increases compared to that in the reference material and the dynamics of the charge decay changes. The understanding of this behavior provides a means of possibility assessing insulator material aging.
|
|
| 7. |
- Ai, Sizhi, et al.
(författare)
-
Causal associations of short and long sleep durations with 12 cardiovascular diseases : linear and nonlinear Mendelian randomization analyses in UK Biobank
- 2021
-
Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 42:34, s. 3349-3357
-
Tidskriftsartikel (refereegranskat)abstract
- Aims Observational studies have suggested strong associations between sleep duration and many cardiovascular diseases (CVDs), but causal inferences have not been confirmed. We aimed to determine the causal associations between genetically predicted sleep duration and 12 CVDs using both linear and nonlinear Mendelian randomization (MR) designs. Methods and results Genetic variants associated with continuous, short (<= 6 h) and long (>= 9 h) sleep durations were used to examine the causal associations with 12 CVDs among 404 044 UK Biobank participants of White British ancestry. Linear MR analyses showed that genetically predicted sleep duration was negatively associated with arterial hypertension, atrial fibrillation, pulmonary embolism, and chronic ischaemic heart disease after correcting for multiple tests (P <0.001). Nonlinear MR analyses demonstrated nonlinearity (L-shaped associations) between genetically predicted sleep duration and four CVDs, including arterial hypertension, chronic ischaemic heart disease, coronary artery disease, and myocardial infarction. Complementary analyses provided confirmative evidence of the adverse effects of genetically predicted short sleep duration on the risks of 5 out of the 12 CVDs, including arterial hypertension, pulmonary embolism, coronary artery disease, myocardial infarction, and chronic ischaemic heart disease (P< 0.001), and suggestive evidence for atrial fibrillation (P < 0.05). However, genetically predicted long sleep duration was not associated with any CVD. Conclusion This study suggests that genetically predicted short sleep duration is a potential causal risk factor of several CVDs, while genetically predicted long steep duration is unlikely to be a causal risk factor for most CVDs. [GRAPHICS] .
|
|
| 8. |
- Alm, Ann-Sophie, et al.
(författare)
-
Variation of lipopolysaccharide-induced acute lung injury in eight strains of mice.
- 2010
-
Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier BV. - 1878-1519 .- 1569-9048. ; 171, s. 157-164
-
Tidskriftsartikel (refereegranskat)abstract
- Clinical and experimental evidence suggests that genetic variations may play an important role in the development of acute lung injury (ALI). Lipopolysaccharide (LPS)-induced ALI models has been widely applied for pathophysiological and pharmacological research. In order to understand the variation of acute pulmonary reactions between mouse strains and find the optimal strain for target-oriented study, the present study investigated the alterations of acute lung hyperinflation, inflammation and injury in C57BL/6J, Balb/cJ, DBA/1J, CD-1, NMRI, DBA/2J, A/J and C3H/HeN mice after the intra-tracheal challenge with LPS. We found that LPS-induced ALI varied between measured variables, durations and strains. General score of LPS-induced acute lung hyperinflation, inflammation and edema followed the order CD-1, A/J, Balb/c, DBA/2J, C57BL/6J, DBA/1J, NMRI, C3H/HeN mice at 4h, and CD-1, C57BL/6J, Balb/c, C3H/HeN, NMRI, A/J, DBA/2J, DBA/1 mice at 24h. Thus, these data provide useful information to select sensitive or resistant strain mouse for understanding genetic variation of pathogenesis and screening of target-oriented drugs.
|
|
| 9. |
- Alm, Ann-Sophie, et al.
(författare)
-
Varying susceptibility of pulmonary cytokine production to lipopolysaccharide in mice.
- 2010
-
Ingår i: Cytokine. - : Elsevier BV. - 1096-0023 .- 1043-4666. ; 49, s. 256-263
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: The lipopolysaccharide (LPS)-induced acute lung injury (ALI) model has been widely applied for pathophysiological and pharmacological research. The aim of present study is to understand the variation of acute pulmonary inflammation between mouse strains. Methods: The present study investigated the susceptibility of acute production of inflammatory mediators, e.g. cytokines, chemokines and others, to LPS in C57BL/6J, Balb/cJ, DBA/1J, CD-1, NMRI, DBA/2J, A/J, and C3H/HeN mice. Results: The susceptibility to intra-tracheal challenge with LPS varied between measured variables, durations and strains. General lung hyper-reactive susceptibility to LPS-induced pulmonary production of 6-8 inflammatory mediators followed the order NMRI, Balb/cJ, C3H/HeN, A/J, C57BL/6J, DBA/1J, DBA/2J and CD-1 mice at 4h, and A/J, C3H/HeN, CD-1, NMRI, C57BL/6J, Balb/cJ, DBA/2J and DBA/1J mice at 24h. Conclusions: Our data provide information for scientists to consider the proper strain of mice for the measurement of specific inflammatory mediators and to select sensitive or resistant mouse strains for understanding genetic variation in the pathogenesis and for the screening of target-oriented drug development.
|
|
| 10. |
- Brütt, Katharina, et al.
(författare)
-
Competition and moral behavior: A meta-analysis of forty-five crowd-sourced experimental designs
- 2023
-
Ingår i: Proceedings of the National Academy of Sciences - PNAS. - : National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 120:23
-
Tidskriftsartikel (refereegranskat)abstract
- Does competition affect moral behavior? This fundamental question has been debated among leading scholars for centuries, and more recently, it has been tested in experimental studies yielding a body of rather inconclusive empirical evidence. A potential source of ambivalent empirical results on the same hypothesis is design heterogeneity-variation in true effect sizes across various reasonable experimental research protocols. To provide further evidence on whether competition affects moral behavior and to examine whether the generalizability of a single experimental study is jeopardized by design heterogeneity, we invited independent research teams to contribute experimental designs to a crowd-sourced project. In a large-scale online data collection, 18,123 experimental participants were randomly allocated to 45 randomly selected experimental designs out of 95 submitted designs. We find a small adverse effect of competition on moral behavior in a meta-analysis of the pooled data. The crowd-sourced design of our study allows for a clean identification and estimation of the variation in effect sizes above and beyond what could be expected due to sampling variance. We find substantial design heterogeneity-estimated to be about 1.6 times as large as the average standard error of effect size estimates of the 45 research designs-indicating that the informativeness and generalizability of results based on a single experimental design are limited. Drawing strong conclusions about the underlying hypotheses in the presence of substantive design heterogeneity requires moving toward much larger data collections on various experimental designs testing the same hypothesis.
|
|
| 11. |
- Chen, Chengshui, et al.
(författare)
-
Preventive and Therapeutic Effects of Phosphoinositide 3-Kinase Inhibitors on Acute Lung Injury
- 2011
-
Ingår i: Chest. - : Elsevier BV. - 1931-3543 .- 0012-3692. ; 140:2, s. 391-400
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Phosphoinositide 3-kinases (PI3Ks) are involved in a number of biologic responses. Recent preclinical studies demonstrated that the PI3K-dominant signal pathway could play an important role in the development of acute lung injury, although the mechanism remains unclear. Methods: CD-1 mice were administered different PI3K inhibitors either intranasally or intragastrically once a day for 3 days before intratracheal instillation of lipopolysaccharide at 4 h and 24 h. Effects of SHBM1009 on lipopolysaccharide-induced capillary permeability, leukocyte distribution and activation, and epithelial cell function were measured. Therapeutic effects of SHBM1009 on pancreatic elastase-induced lung injury were evaluated in rats. Results: The data demonstrated that the local delivery of PI3K inhibitors played more effective roles in the prevention of endotoxin-induced lung injury than the systemic delivery. The preventive effects of PI3K inhibitors varied most likely because of chemical properties, targeting sites, and pharmacokinetics. The local PI3K inhibitors prevented both endotoxin- and elastase-induced lung injury in mice and rats, possibly through directly inhibiting or inactivating the function of airway epithelial cells, which could not produce chemoattractant factors to activate neutrophils and macrophages. Conclusions: PI3K may be a therapeutic target for lung injury, and local delivery of PI3K inhibitors may be one of the optimal approaches for the therapy. CHEST 2011; 140(2):391-400
|
|
| 12. |
- Du, Yaoyao, et al.
(författare)
-
Cartilage Oligomeric Matrix Protein Inhibits Vascular Smooth Muscle Calcification by Interacting With Bone Morphogenetic Protein-2.
- 2011
-
Ingår i: Circulation Research. - 1524-4571. ; 108, s. 79-917
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale: Vascular calcification is a significant contributor to cardiovascular morbidity and mortality. We recently reported that cartilage oligomeric matrix protein (COMP) is pivotal for maintaining the homeostasis of vascular smooth muscle cells (VSMCs). Whether COMP affects the process of vascular calcification is unknown. Objective: We aimed to test whether COMP modulates vascular calcification. Methods and Results: VSMC calcification in vitro was induced by calcifying media containing high inorganic phosphate or calcium. In vivo medial vessel calcification was induced in rats by 5/6 nephrectomy with a high-phosphate diet or by periadventitial application of CaCl(2) to the abdominal aorta. COMP protein level was markedly reduced in both calcified VSMCs and arteries. COMP deficiency remarkably exacerbated VSMC calcification, whereas ectopic expression of COMP greatly reduced calcification. Furthermore, COMP knockdown facilitated osteogenic markers expression by VSMCs even in the absence of calcifying media. By contrast, COMP overexpression significantly inhibited high phosphate- or high calcium-induced VSMC osteochondrogenic transition. Induction of osteogenic marker expression by COMP silencing was reversed by a soluble form of bone morphogenetic protein (BMP)-2 receptor IA, which suggests a BMP-2-dependent mechanism. Our data revealed that COMP bound directly to BMP-2 through the C terminus, inhibited BMP-2 receptor binding, and blocked BMP-2 osteogenic signaling, indicating COMP inhibits osteochondrogenic transition of VSMCs at least partially through inhibiting BMP-2. Conclusions: Our data strongly suggest that COMP is a novel inhibitor of vascular calcification. The imbalance between the effects of COMP and BMP-2 may provide new insights into the pathophysiology of vascular calcification.
|
|
| 13. |
|
|
| 14. |
- Fu, Yunfei, et al.
(författare)
-
Fundamental Characteristics of Tropical Rain Cell Structures as Measured by TRMM PR
- 2020
-
Ingår i: Journal of Meteorological Research. - : Springer Science and Business Media LLC. - 2095-6037 .- 2198-0934. ; 34:6, s. 1129-1150
-
Tidskriftsartikel (refereegranskat)abstract
- Rain cells are the most elementary unit of precipitation system in nature. In this study, fundamental geometric and physical characteristics of rain cells over tropical land and ocean areas are investigated by using 15-yr measurements of the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The rain cells are identified with a minimum bounding rectangle (MBR) method. The results indicate that about 50% of rain cells occur at length of about 20 km and width of 15 km. The proportion of rain cells with length > 200 km and width > 100 km is less than 1%. There is a a log-linear relationship between the mean length and width of rain cells. Usually, for the same horizontal geometric parameters, rain cells tend to be square horizontally and lanky vertically over land, while vertically squatty over ocean. The rainfall intensity of rain cells varies from 0.4 to 10 mm h(-1) over land to 0.4-8 mm h(-1) over ocean. Statistical results indicate that the occurrence frequency of rain cells decreases as the areal fraction of convective precipitation in rain cells increases, while such frequency remains almost invariant when the areal fraction of stratiform precipitation varies from 10% to 80%. The relationship between physical and geometric parameters of rain cells shows that the mean rain rate of rain cells is more frequently associated with the increase of their area, with the increasing rate over land greater than that over ocean. The results also illustrate that heavy convective rain rate prefers to occur in larger rain cells over land while heavy stratiform rain rate tends to appear in larger rain cells over ocean. For the same size of rain cells, the areal fraction and the contribution of convective precipitation are about 10%-15% higher over land than over ocean.
|
|
| 15. |
- Gross, Franz, et al.
(författare)
-
50 Years of quantum chromodynamics : Introduction and Review
- 2023
-
Ingår i: European Physical Journal C. - 1434-6044. ; 83:12
-
Forskningsöversikt (refereegranskat)abstract
- Quantum Chromodynamics, the theory of quarks and gluons, whose interactions can be described by a local SU(3) gauge symmetry with charges called “color quantum numbers”, is reviewed; the goal of this review is to provide advanced Ph.D. students a comprehensive handbook, helpful for their research. When QCD was “discovered” 50 years ago, the idea that quarks could exist, but not be observed, left most physicists unconvinced. Then, with the discovery of charmonium in 1974 and the explanation of its excited states using the Cornell potential, consisting of the sum of a Coulomb-like attraction and a long range linear confining potential, the theory was suddenly widely accepted. This paradigm shift is now referred to as the November revolution. It had been anticipated by the observation of scaling in deep inelastic scattering, and was followed by the discovery of gluons in three-jet events. The parameters of QCD include the running coupling constant, αs(Q2) , that varies with the energy scale Q2 characterising the interaction, and six quark masses. QCD cannot be solved analytically, at least not yet, and the large value of αs at low momentum transfers limits perturbative calculations to the high-energy region where Q2≫ΛQCD2≃ (250 MeV) 2 . Lattice QCD (LQCD), numerical calculations on a discretized space-time lattice, is discussed in detail, the dynamics of the QCD vacuum is visualized, and the expected spectra of mesons and baryons are displayed. Progress in lattice calculations of the structure of nucleons and of quantities related to the phase diagram of dense and hot (or cold) hadronic matter are reviewed. Methods and examples of how to calculate hadronic corrections to weak matrix elements on a lattice are outlined. The wide variety of analytical approximations currently in use, and the accuracy of these approximations, are reviewed. These methods range from the Bethe–Salpeter, Dyson–Schwinger coupled relativistic equations, which are formulated in both Minkowski or Euclidean spaces, to expansions of multi-quark states in a set of basis functions using light-front coordinates, to the AdS/QCD method that imbeds 4-dimensional QCD in a 5-dimensional deSitter space, allowing confinement and spontaneous chiral symmetry breaking to be described in a novel way. Models that assume the number of colors is very large, i.e. make use of the large Nc -limit, give unique insights. Many other techniques that are tailored to specific problems, such as perturbative expansions for high energy scattering or approximate calculations using the operator product expansion are discussed. The very powerful effective field theory techniques that are successful for low energy nuclear systems (chiral effective theory), or for non-relativistic systems involving heavy quarks, or the treatment of gluon exchanges between energetic, collinear partons encountered in jets, are discussed. The spectroscopy of mesons and baryons has played an important historical role in the development of QCD. The famous X,Y,Z states – and the discovery of pentaquarks – have revolutionized hadron spectroscopy; their status and interpretation are reviewed as well as recent progress in the identification of glueballs and hybrids in light-meson spectroscopy. These exotic states add to the spectrum of expected qq¯ mesons and qqq baryons. The progress in understanding excitations of light and heavy baryons is discussed. The nucleon as the lightest baryon is discussed extensively, its form factors, its partonic structure and the status of the attempt to determine a three-dimensional picture of the parton distribution. An experimental program to study the phase diagram of QCD at high temperature and density started with fixed target experiments in various laboratories in the second half of the 1980s, and then, in this century, with colliders. QCD thermodynamics at high temperature became accessible to LQCD, and numerical results on chiral and deconfinement transitions and properties of the deconfined and chirally restored form of strongly interacting matter, called the Quark–Gluon Plasma (QGP), have become very precise by now. These results can now be confronted with experimental data that are sensitive to the nature of the phase transition. There is clear evidence that the QGP phase is created. This phase of QCD matter can already be characterized by some properties that indicate, within a temperature range of a few times the pseudocritical temperature, the medium behaves like a near ideal liquid. Experimental observables are presented that demonstrate deconfinement. High and ultrahigh density QCD matter at moderate and low temperatures shows interesting features and new phases that are of astrophysical relevance. They are reviewed here and some of the astrophysical implications are discussed. Perturbative QCD and methods to describe the different aspects of scattering processes are discussed. The primary parton–parton scattering in a collision is calculated in perturbative QCD with increasing complexity. The radiation of soft gluons can spoil the perturbative convergence, this can be cured by resummation techniques, which are also described here. Realistic descriptions of QCD scattering events need to model the cascade of quark and gluon splittings until hadron formation sets in, which is done by parton showers. The full event simulation can be performed with Monte Carlo event generators, which simulate the full chain from the hard interaction to the hadronic final states, including the modelling of non-perturbative components. The contribution of the LEP experiments (and of earlier collider experiments) to the study of jets is reviewed. Correlations between jets and the shape of jets had allowed the collaborations to determine the “color factors” – invariants of the SU(3) color group governing the strength of quark–gluon and gluon–gluon interactions. The calculated jet production rates (using perturbative QCD) are shown to agree precisely with data, for jet energies spanning more than five orders of magnitude. The production of jets recoiling against a vector boson, W± or Z, is shown to be well understood. The discovery of the Higgs boson was certainly an important milestone in the development of high-energy physics. The couplings of the Higgs boson to massive vector bosons and fermions that have been measured so far support its interpretation as mass-generating boson as predicted by the Standard Model. The study of the Higgs boson recoiling against hadronic jets (without or with heavy flavors) or against vector bosons is also highlighted. Apart from the description of hard interactions taking place at high energies, the understanding of “soft QCD” is also very important. In this respect, Pomeron – and Odderon – exchange, soft and hard diffraction are discussed. Weak decays of quarks and leptons, the quark mixing matrix and the anomalous magnetic moment of the muon are processes which are governed by weak interactions. However, corrections by strong interactions are important, and these are reviewed. As the measured values are incompatible with (most of) the predictions, the question arises: are these discrepancies first hints for New Physics beyond the Standard Model? This volume concludes with a description of future facilities or important upgrades of existing facilities which improve their luminosity by orders of magnitude.
|
|
| 16. |
- Li, Hongliang, et al.
(författare)
-
Catalytic performance and characterization of Al2O3-supported Pt-Co catalyst coatings for preferential CO oxidation in a micro-reactor
- 2010
-
Ingår i: Applied Catalysis A. - : Elsevier BV. - 0926-860X .- 1873-3875. ; 387:1-2, s. 215-223
-
Tidskriftsartikel (refereegranskat)abstract
- Platinum-cobalt (Pt-Co) catalyst coatings are studied for preferential oxidation of carbon monoxide (PROX) ill hydrogen-rich gas streams. Experimental results show a role for cobalt in improving catalytic activity. The most active catalyst coating can decrease carbon monoxide concentrations from 1% to a value of less than 10 ppm for GHSV values ranging from 40,000 to 120,000 ml g(-1) h(-1). This catalyst coating can work at a wide window of operation ill terms of temperature. Transmission electron microscopy, selected-area electron diffraction, and diffuse reflectance infrared Fourier transform spectroscopy show that the addition of Co forms Pt3Co intermetallic compounds and slightly increases the average particle size. In situ laser Raman spectroscopy reveals the co-existence of Co metal and its oxides on the catalyst surface, due to gradual oxidation of Co by gas phase oxygen within the initial stage of the PROX reaction. The promotional effect of Co during PROX is confirmed and ascribed to this Pt3Co intermetallic compound and the synergetic effect of Co-0 and Co chi+. The high accessibility of the reactant to Pt3Co species appears favorable and crucial for PROX.
|
|
| 17. |
- Li, Wengui, et al.
(författare)
-
Participatory and Transdisciplinary Studies of Brucella Infection in Humans and Animals in Yunnan Province, China-Lessons Learned
- 2021
-
Ingår i: Tropical Medicine and Infectious Disease. - : MDPI. - 2414-6366. ; 6:3
-
Tidskriftsartikel (refereegranskat)abstract
- Brucellosis is an important zoonosis occurring globally. In addition to the risk for disease in humans, the disease causes production losses, since the disease in livestock is characterized by abortion and other reproductive failures. The disease is a public health concern in China, but no information is available on knowledge, perception and awareness of potential risk groups such as farmers, butchers and animal health workers; yet successful control requires compliance of those affected groups to be effective. Following the principles of the Ecohealth approach, emphasis was given to participation of all relevant stakeholders, use of qualitative and quantitative tools, and cross-sectorial collaboration. Data collection included on-farm questionnaires (N = 192) and collection of bulk milk samples of goat (N = 40), cattle (N = 45) and buffalo (N = 41) from farms, as well as serum samples (N = 228) from humans. Milk samples were tested with an ELISA for presence of antibodies, while a serum agglutination test was used for human samples. Qualitative work included 17 focus group discussion (FGD) with villagers and 47 in-depth interviews (IDI) with village animal health workers, doctors, and butchers, focused on knowledge, perception and awareness on zoonoses including brucellosis. Results from questionnaires indicate that abortions are a common problem; cattle with abortion history are kept for further insemination and the milk still consumed or sold. Antibodies against Brucella were detected in cows' (5/45) and goats' (1/40) milk samples, and in human samples (5/126) in Yiliang, while in Mangshi, all buffalo (N = 41) and humans (N = 102) were negative. FGD and IDI results showed an alarmingly low knowledge and awareness on zoonoses; particularly, low awareness about brucellosis was noted, even among the professional groups. Collaboration between village animal health workers and doctors was uncommon. No confirmed brucellosis cases were found in retrospective investigation of hospital and veterinary stations. This study demonstrates the presence of brucellosis in livestock and humans in Yunnan, indicating a non-negligible risk for humans. It is also made apparent that there is a need for increased awareness among both farmers and professionals in order to reduce the risk of zoonotic transmissions.
|
|
| 18. |
- Li, Xiangdong A., et al.
(författare)
-
Design and Evaluation of Cross-Objects User Interface for Whiteboard Interaction
- 2017
-
Ingår i: Distributed, Ambient and Pervasive Interactions. - Cham : Springer. - 9783319586960 - 9783319586977 ; , s. 180-191
-
Konferensbidrag (refereegranskat)abstract
- Whiteboard has long been an important tool for education and communication, and nowadays it embraces display functions and other interactive features such as pen pointing and selecting of digital contents. Despite the enhanced interactivity, it is often time- and cost-consuming to implement specific apparatus for different whiteboard interactions. Therefore, we aimed at incorporating physical-world objects (e.g. Lego Rubik’s cubes) as the cross-objects user interface for multiple whiteboard interaction tasks without incurring heavy development work. The user interface utilised electromagnetic technique to extract electromechanical signals and recognised normal objects, thus extended the generality. To further understand effectiveness of the user interface, we implemented a low-fidelity prototype and conducted within-subject evaluation. The results showed the cross-objects user interface was natural, responsive, and easy of learning as the conventional whiteboard. Moreover, the user interface outperformed over the conventional one in the perspectives of configuration efficiency and versatility of multiple interaction tasks. Given these findings, practical implications for future tangible user interface design for whiteboard interactions are discussed.
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Li, Xiangdong, 1965
(författare)
-
Adaptive Finite Element Procedures in Structural Dynamics
- 1996
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with a posteriori error estimation and adaptivity in finite element procedures for the analysis of structural dynamic problems. First, error estimation and adaptivity for the Newmark time integration method are studied. Based on a postprocessing technique, a posteriori local error estimates for displacements, velocities and, thus, also the total energy norm error estimate are derived. An adaptive time-stepping procedure is described. It adjusts the time step size automatically so that the estimated local errors are controlled within a specified tolerance. Secondly, a postprocessed type of a posteriori error estimate and an h-adaptive procedure for the semidiscrete finite element method for two-dimensional continuous problems are presented. In space, the superconvergent patch recovery technique (SPR) is used for determining higher order accurate solutions and, thus, a spatial error estimate. In time, the local error estimate developed above is adopted. The presented h-adaptive finite element procedure is able to update the spatial mesh and the time step so that the discretization errors both in space and time are under control. Then, a time-discontinuous Galerkin finite element method (or DG method) is studied, by which both displacements and velocities are approximated as piecewise linear functions in time and may be discontinuous at the discrete time levels. An iterative solution algorithm is proposed for solving the resulted system of coupled equations. By using the jumps of the displacements and the velocities in the total energy norm as a local error indicator, an adaptive time-stepping procedure similar to the one for the Newmark method is implemented. It is shown that, while the Newmark method is only of second-order accuracy and is unable to avoid the effect of the spurious high modes, the DG method considered here is of third-order accuracy and is capable of filtering out the effect of spurious high modes. Finally, the DG method is applied to two-dimensional continuous problems. The method approximates both displacements and velocities as piecewise linear functions in space and time simultaneously and permits them being discontinuous at the discrete time levels. The adaptive procedure is based on using the Zienkiewicz-Zhu error estimate in space and the jumps of displacements and velocities in the total energy norm as an error indicator in time. It is demonstrated that this space-time finite element method is of second-order accuracy in space (in L2) and third-order accuracy in time, and the adaptive procedure is capable of updating the spatial mesh and time step automatically so as to control the discretization errors within specified tolerances, thus, making the solutions reliable and the computation efficient.
|
|
| 24. |
|
|
| 25. |
- Li, Xiangdong, et al.
(författare)
-
Mobile Phone-Based Device for Personalised Tutorials of 3D Printer Assembly
- 2019
-
Ingår i: Human-Computer Interaction. Recognition and Interaction Technologies. - Cham : Springer. - 9783030226428 - 9783030226435 ; , s. 37-48
-
Konferensbidrag (refereegranskat)abstract
- There are a number of studies exploring materials and mechanisms of 3D printers that can help product designers develop and evaluate interactive systems efficiently. As 3D printers are increasingly adopted, designers are more likely to encounter difficulties in assembling 3D printers on their own, as the assembly process involves specialised skills and knowledge of fitting components in right positions. Conventional solutions use text and video manuals but still requires high understandings of the assembly. We designed and evaluated the mobile phone-based device for personalised tutorials of 3D printer assembly. The device consists of a modified dongle and mobile phone application. The former detects electromagnetic signals upon physical contacts with the components and the latter displays tutorials accordingly. The contributions include the device design with electromagnetic signal-based object detection and importantly, the approach to integrating component touching with component detection for personalised interactions. Generalising implications for the approach are discussed.
|
|
| 26. |
- Li, Xiangdong, et al.
(författare)
-
Predicting user visual attention in virtual reality with a deep learning model
- 2021
-
Ingår i: Virtual Reality. - : Springer Science and Business Media LLC. - 1359-4338 .- 1434-9957. ; 25, s. 1123-1136
-
Tidskriftsartikel (refereegranskat)abstract
- Recent studies show that user's visual attention during virtual reality museum navigation can be effectively estimated with deep learning models. However, these models rely on large-scale datasets that usually are of high structure complexity and context specific, which is challenging for nonspecialist researchers and designers. Therefore, we present the deep learning model, ALRF, to generalise on real-time user visual attention prediction in virtual reality context. The model combines two parallel deep learning streams to process the compact dataset of temporal-spatial salient features of user's eye movements and virtual object coordinates. The prediction accuracy outperformed the state-of-the-art deep learning models by reaching record high 91.03%. Importantly, with quick parametric tuning, the model showed flexible applicability across different environments of the virtual reality museum and outdoor scenes. Implications for how the proposed model may be implemented as a generalising tool for adaptive virtual reality application design and evaluation are discussed.
|
|
| 27. |
|
|
| 28. |
- Li, Xiangdong, et al.
(författare)
-
Towards personalized virtual reality touring through cross-object user interfaces
- 2019
-
Ingår i: Personalized Human-Computer Interaction. - : Walter de Gruyter. - 9783110552485 ; , s. 201-222
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Real-time adaptation is one of the most important problems that currently require a solution in the field of personalized human-computer interaction. For conventional desktop system interactions, user behaviors are acquired to develop models that support context-aware interactions. In virtual reality interactions, however, users operate tools in the physical world but view virtual objects in the virtual world. This dichotomy constrains the use of conventional behavioral models and presents difficulties to personalizing interactions in virtual environments. To address this problem, we propose the cross-object user interfaces (COUIs) for personalized virtual reality touring. COUIs consist of two components: a Deep Learning algorithm-based model using convolutional neural networks (CNNs) to predict the user’s visual attention from the past eye movement patterns to determine which virtual objects are likely to be viewed next, and delivery mechanisms that determine what should when and where be displayed on the user interface. In this chapter, we elaborate on the training and testing of the prediction model and evaluate the delivery mechanisms of COUIs through a cognitive walk-through approach. Furthermore, the implications for using COUIs to personalize interactions in virtual reality (and other environments such as augmented reality and mixed reality) are discussed.
|
|
| 29. |
- Li, Zerui, et al.
(författare)
-
A Thermal Excitation Based Partial Discharge Detection Method for Cable Accessory
- 2023
-
Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 38:4, s. 2703-2710
-
Tidskriftsartikel (refereegranskat)abstract
- Partial discharge (PD) test has been widely used in condition assessment for power cables. However, discharge extinguish phenomenon occurred in PD detection hinders the effective detection of potential defects in cable accessories. For this reason, a novel PD detection method based on thermal excitation is proposed in this paper to eliminate the extinguish phenomenon and to detect the potential defects in earlier stage. First, the physical processes in PD activity and the reasons for discharge extinguishing are introduced. Then, the principle and mechanism of the thermal excitation detection method are described and analyzed respectively, that is excitation by external heating to break the dynamic equilibrium of charge movement within the defect and further stimulate new discharges. And a finite element simulation model is constructed to determine the thermal excitation parameters. Finally, the effectiveness is validated by performing thermal excitation-based PD test on some defective cables. The experimental results show that this method can significantly increase the number of discharges in off-line test, while also stimulating PD of higher amplitudes in on-line monitoring. This method can improve the sensitivity of PD detection for cable accessories and detect potential defects in early stage.
|
|
| 30. |
- Liu, Daosheng, et al.
(författare)
-
Magnetic Properties and Vibration Characteristics of Amorphous Alloy Strip and Its Combination
- 2019
-
Ingår i: IET Electric Power Applications. - : Institution of Engineering and Technology (IET). - 1751-8660 .- 1751-8679. ; 13:10, s. 1589-1597
-
Tidskriftsartikel (refereegranskat)abstract
- Although the cores made with amorphous metal alloy have lowered no-load losses compared with the orientation silicon steel cores, a high cost and noise level are inevitable because the magnetostriction for amorphous metal alloy strip is larger than the ordinary one. This paper mainly focused on the experimental systems and methods for magnetic properties measurement, vibration characteristics and noise level of amorphous alloy strip and combinations. The vibration characteristics and noise level of amorphous alloy composite strip were also studied. The influence of annealing process on magnetic energy, vibration characteristics and noise level of amorphous alloy core were analyzed in detail as well. All the testing results and analysis above are helpful for the transformer manufacturers, and they can replace the expensive amorphous alloy metal strip with the combination ones to reduce the noise and the cost of the cores.
|
|
| 31. |
- Liu, Daosheng, et al.
(författare)
-
Optimization of Mass Fraction and Particle Size of TiO2 Additives in Application of HVDC Transformer Insulation
- 2019
-
Ingår i: Proceedings - IEEE International Conference on Dielectric Liquids. - 2153-3733 .- 2153-3725. ; 2019-June
-
Konferensbidrag (refereegranskat)abstract
- With the fast development of high voltage direct current (HVDC) transmission technology, higher electrical insulation properties are demanded in application of HVDC converter transformers. The nano adding in the cellulose insulation is a kind of effect method to enhance their electrical insulation properties. In this paper, nano-TiO2 particles with four different diameters (5 nm, 10 nm, 20 nm and 30 nm) and four different loading ratios (1 wt%, 3 wt%, 5 wt% and 7 wt%) are added during preparation of the insulation cellulose paper. To evaluate their dielectric properties, DC breakdown test, partial discharge inception voltage test, the accumulating properties of the surface charge dynamics and trap distribution characteristic are performed on the prepared nano-TiO2 modified paper samples. The experimental results show that the DC breakdown voltage and the partial discharge inception voltage of oil-immersed composition insulating paper are significantly improved by adding nano-TiO2 particles. According to the testing data, the optimum combination of 10 nm particle size and 5 wt% mass fractions were obtained, and the modification mechanism of nano-TiO2 of the nano-composition insulation were presented in the paper.
|
|
| 32. |
- Lou, Xiaolong, et al.
(författare)
-
An Empirical Evaluation on Arm Fatigue in Free Hand Interaction and Guidelines for Designing Natural User Interfaces in VR
- 2020
-
Ingår i: Virtual, Augmented and Mixed Reality. Design and Interaction. - Cham : Springer. - 9783030496944 - 9783030496951 ; , s. 313-324
-
Konferensbidrag (refereegranskat)abstract
- This research had a systematic study on arm fatigue issue in free hand interaction in VR environment and explored how arm fatigue influenced free hand interaction accuracy. A specifically designed target-acquisition experiment was conducted with 24 volunteered participants (7 left-handedness, 17 right-handedness) recruited. The experiment results indicated that (1) arm fatigue resulted in short durations of hand operation, or frequent alternations of operating hand. The user’s dominant hand had a more durable operation than the non-dominant one; (2) hand operate position had a significant effect on arm fatigue level, a bent arm posture was found to be more labor-saving than an extended arm posture, (3) hand operation at a higher position (e.g., at the head height) perceived arm fatigue more easily than that at a lower position (e.g., at the waist height); and (4) arm fatigue impact hand interaction accuracy negatively.
|
|
| 33. |
- Lou, Xiaolong, et al.
(författare)
-
Distance effects on visual search and visually guided freehand interaction on large displays
- 2022
-
Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 90
-
Tidskriftsartikel (refereegranskat)abstract
- Different from mouse-based and touch-based interactions at a static distance, motion-sensing interaction on a large display is typically performed at varying distances ranging from an arm's length to several metres. To investigate the effect of distance on visual search and freehand interaction performance, an empirical experiment was conducted; 30 participants were recruited to complete a series of target search and freehand selection tasks on large displays, which were 1.6 and 2.4 m wide, respectively. The results indicated that (1) the user-preferred viewing distance was positively related to the physical size of the display: a larger display size corresponded to a larger viewing distance. (2) The viewing distance had a two-sided effect on the visual search time efficiency. At a close range, increasing distance improved the search time efficiency; but at a farther range, the efficiency decreased. (3) An optimal field of view at which visual search was most efficient was found; (4) however, increasing the distance lowered freehand interaction efficiency and accuracy. Changing the distance also caused variations in the performance on divided large display areas: (5) the visual search efficiency on the upper area was higher than that on the lower area, increasing the distance reduced the difference; (6) freehand interaction efficiency and accuracy on the lower area outperformed that on the upper area, increasing the distance also reduced the difference. Implications were discussed for building more efficient and user-friendly large display-based user interfaces.
|
|
| 34. |
- Lou, Xianglong, et al.
(författare)
-
Effects of User’s Hand Orientation and Spatial Movements on Free Hand Interactions with Large Displays
- 2018
-
Ingår i: International Journal of Human-Computer Interaction. - : Informa UK Limited. - 1044-7318 .- 1532-7590. ; 34:6, s. 519-532
-
Tidskriftsartikel (refereegranskat)abstract
- In motion-sensing interaction with large displays through bare hands, we can observe that users alternate their hands and move their bodies frequently. What cause such actions and how these actions affect free hand interaction results are less systematically investigated. To address this gap in knowledge, we conducted studies on Pointer-Acceleration (PA)-based free hand interactions of target selection and found that (1) users made more frequent hand alternations when selecting small targets with large movement amplitudes, as in such cases users were not only affected by observable arm fatigue, but were also motivated to switch hands for higher selection accuracy and convenience; (2) hand alternation led to the hand orientation effects: target selection on display areas at the operating hand’s side was more efficient and accurate than that at the opposite side; (3) large movement amplitudes on the user interface increased users’ physical movements in front of the large display, which harmed selection efficiency; (4) selection of small targets led to a closer interaction distance, while large movement amplitudes led to a larger interaction distance; and (5) selection results were affected by interaction distances, as users gained high efficiency, but low accuracy at a large distance and low efficiency, but high accuracy at a close distance. Given these results, this article discusses practical implications for applying PA-based free hand interaction techniques and designing related user interfaces on large displays.
|
|
| 35. |
- Lou, Xiaolong, et al.
(författare)
-
Hand-adaptive user interface : improved gestural interaction in virtual reality
- 2021
-
Ingår i: Virtual Reality. - : Springer Science and Business Media LLC. - 1359-4338 .- 1434-9957. ; 25, s. 367-382
-
Tidskriftsartikel (refereegranskat)abstract
- Most interactive user interfaces (UIs) for virtual reality (VR) applications are based on the traditional eye-centred UI design principle, which primarily considers the user's visual searching efficiency and comfort, but the hand operation performance and ergonomics are relatively less considered. As a result, the hand interaction in VR is often criticized as being less efficient and precise. In this paper, the user's arm movement features, such as the choice of the hand being used and hand interaction position, are hypothesized to influence the interaction results derived from a VR study. To verify this, we conducted a free hand target selection experiment with 24 participants. The results showed that (a) the hand choice had a significant effect on the target selection results: for a left hand interaction, the targets located in spaces to the left were selected more efficiently and accurately than those in spaces to the right; however, in a right hand interaction, the result was reversed, and (b) the free hand interactions at lower positions were more efficient and accurate than those at higher positions. Based on the above findings, this paper proposes a hand-adaptive UI technique to improve free hand interaction performance in VR. A comprehensive comparison between the hand-adaptive UI and traditional eye-centred UI was also conducted. It was shown that the hand-adaptive UI resulted in a higher interaction efficiency and a lower physical exertion and perceived task difficulty than the traditional UI.
|
|
| 36. |
|
|
| 37. |
- Moshfegh, Ramin, et al.
(författare)
-
Gradient-based refinement indicators in adaptive finite element analysis with special reference to sheet metal forming
- 2000
-
Ingår i: Engineering computations. - 0264-4401 .- 1758-7077. ; 17:8, s. 910-932
-
Tidskriftsartikel (refereegranskat)abstract
- Two mesh refinement indicators based on the gradients of effective stress (GSIG) and effective plastic strain (GEPS), respectively, are proposed for adaptive finite element analysis of the large deformation, quasi-static or dynamic response of shell structures. The mesh refinement indicators are based on equi-distributing the variation of stresses or plastic strains over the elements of the mesh. A program module is developed and implemented in the non-linear explicit finite element code LS-DYNA. This module provides element-wise refinement evaluations so that selective mesh refinements are carried out in regions of the mesh where the values of local indicators exceed a user-specified tolerance. The FE model of a conventional deep drawing process is used as a numerical model, including both material and geometrical non-linearities, in order to demonstrate the versatility of the two refinement indicators. Four different refinement indicators, based on angle change, thickness change, GSIG and GEPS, are applied in this investigation. The numerical results are compared with experimental results regarding the thickness distribution versus cup height, cup height variation versus circumference angle, effective plastic strain in the deformed sheet and punch force. It is shown that the proposed indicators can identify finite elements which have high gradients of effective stress or effective plastic strain so that the mesh is refined in the regions undergoing the most severe deformations and the numerical results are improved.
|
|
| 38. |
- Soroudi, Azadeh, 1979, et al.
(författare)
-
Highly insulating thermoplastic nanocomposites based on a polyolefin ternary blend for high-voltage direct current power cables
- 2022
-
Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 14:21, s. 7927-7933
-
Tidskriftsartikel (refereegranskat)abstract
- Octyl-silane-coated Al2O3 nanoparticles are found to be a promising conductivity-reducing additive for thermoplastic ternary blends comprising low-density polyethylene (LDPE), isotactic polypropylene and a styrenic copolymer. The ternary blend nanocomposites were prepared by compounding the blend components together with an LDPE-based masterbatch that contained the nanoparticles. The nanoparticles did not affect the superior stiffness of the ternary blends, compared to neat LDPE, between the melting temperatures of the two polyolefins. As a result, ternary blend nanocomposites comprising 38 wt% polypropylene displayed a storage modulus of more than 10 MPa up to at least 150 °C, independent of the chosen processing conditions. Moreover, the ternary blend nanocomposites featured a low direct-current electrical conductivity of about 3 × 10−15 S m−1 at 70 °C and an electric field of 30 kV mm−1, which could only be achieved through the presence of both polypropylene and Al2O3 nanoparticles. This synergistic conductivity-reducing effect may facilitate the design of more resistive thermoplastic insulation materials for high-voltage direct current (HVDC) power cables.
|
|
| 39. |
- Sun, Lingyun, et al.
(författare)
-
Cross-objects user interfaces for video interaction in virtual reality museum context
- 2018
-
Ingår i: Multimedia tools and applications. - : Springer Science and Business Media LLC. - 1380-7501 .- 1573-7721. ; 77:21, s. 29013-29041
-
Tidskriftsartikel (refereegranskat)abstract
- Museums are good places for learning and nowadays many museums are integrating digital media such as video and increasingly moving towards using virtual reality. In the physical world people used to seek information from object surfaces e.g. posters on the wall and this has been used as a metaphor in the virtual reality museum: numerous videos were inhabited within virtual objects and shaped cross-objects user interfaces (COUIs). However, how such interfaces perform for video interactions still needs more investigations. In this study we implemented and investigated COUIs in comparison with the conventional card-style user interfaces and the plain virtual reality user interfaces in the virtual reality museum. The results reported no significant differences in the perceived usability or learning experience between these user interfaces, except the COUIs had a lower level of satisfaction than the card-style user interfaces. However, the COUIs showed greater efficiency with shorter eye fixation durations and higher saccade frequencies, and within these COUIs instances, namely the fully-detached, semi-attached, and fully-attached COUIs, the fully-attached instance was closest to the form of interacting with physical object surfaces and it reported highest efficiency as well. Rationales behind these results and implications generalising for the future design of COUIs, are discussed.
|
|
| 40. |
- Sun, Xun, et al.
(författare)
-
Large recoverable strain with suitable transition temperature in TiNb-based multicomponent shape memory alloys : First-principles calculations
- 2021
-
Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 221
-
Tidskriftsartikel (refereegranskat)abstract
- TiNb-based shape memory alloys (SMAs) have great potentials in biomaterials. However, high transition temperature or small recoverable strain limit their application. Using first-principles method, we systematically study the recoverable strain and transition temperature of TiNb-based binary, ternary, and high-entropy alloys (HEAs), and aim to lower the transition temperature and improve the recoverable strain at the same time. We find that the employed approach describes accurately the lattice strain by comparing with the available experimental results. It is well known that there is a positive correlation between lattice strain and recoverable strain in SMAs. Thus, we have evaluated the magnitude of recoverable strain of SMAs by calculating the lattice strain. Meanwhile, we correlate the available measured martensitic transformation start temperature (M-s) with the calculated energy difference between beta and alpha'' phases in Ti-Nb binary alloys. According to this relation, we evaluate the M-s in other TiNb-based alloys. We find that Zr is a good alloying element that can decrease considerably the M-s and keep the lattice (recoverable) strain almost unchanged simultaneously. Finally, an Al-containing Ti24Nb25Zr24S24Al3 HEA has been designed to have simultaneously large recoverable strain and low transition temperature.
|
|
| 41. |
- Wang, Xiaohuan, et al.
(författare)
-
Using Machine Learning Method to Discover Hygrothermal Transfer Patterns from the Outside of the Wall to Interior Bamboo and Wood Composite Sheathing
- 2022
-
Ingår i: Buildings. - : MDPI AG. - 2075-5309. ; 12:7, s. 898-898
-
Tidskriftsartikel (refereegranskat)abstract
- To identify hygrothermal transfer patterns of exterior walls is a crucial issue in the design, assessment, and construction of buildings. Temperature and relative humidity, as sensor monitoring data, were collected from the outside of the wall to interior bamboo and wood composite sheathing over the year in Huangshan Mountain District, Anhui Province, China. Combining the machine learning method of reservoir computing (RC) with agglomerative hierarchical clustering (AHC), a novel clustering framework was built for better extraction of the characteristics of hygrothermal transfer on the time series data. The experimental results confirmed the hypothesis that the change in the temperature and relative humidity of the outside of the wall (RHT12) dominated the change of the interior sheathing (RHT11). The delay time between two adjacent peaks in temperature was 1 to 2 h, while that in relative humidity was 1 to 4 h from the outside of the wall to interior bamboo and wood composite sheathing. There was no significant difference in temperature peak delay time between April and July. Temperature peak delay time was 50 to 120 min. However, relative humidity peak delay time was 100 to 240 min in April, whereas it was 20 to 120 min in July. The impact formed a relatively linear relationship between outdoor temperature and relative humidity peak delay time. The hygrothermal transfer patterns were characterized effectively by the peak delays. The discovery of the hygrothermal transfer patterns for the bamboo and wood composite walls using the machine learning method will facilitate the development of energy-efficient and durable bamboo and wood composite wall materials and structures.
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
|
|
| 45. |
|
|
| 46. |
|
|
| 47. |
|
|
| 48. |
|
|
| 49. |
|
|
| 50. |
|
|
