254 research outputs found
Implementing an Environmental Citizen Science Project: Strategies and Concerns from Educators’ Perspectives
Citizen science seems to have a natural alignment with environmental and science education, but incorporating citizen science projects into education practices is still a challenge for educators from different education contexts. Based on participant observation and interview data, this paper describes the strategies educators identified for implementing an environmental citizen science project in different education contexts (i.e., classroom teaching, aquarium exhibits, and summer camp) and discusses the practical concerns influencing independent implementation by educators. The results revealed different implementation strategies that are shaped by four categories of constraints: 1) organizational and institutional policies, 2) educators’ time and material resources, 3) learners’ needs and abilities, and 4) aspects of citizen science project design that constitute a higher barrier to entry for educators managing student contributions. We developed a simple two-dimensional model to demonstrate the types of adaptations that educators made to citizen science projects and discussed the potential role of persuasive technologies to address some of the gaps and better facilitate educator and learner participation
Gas Fluidization and Pneumatic Conveying in Confined Beds: A Numerical Study
The fluidization phenomena for gas-fine particle two-phase flow is numerically simulated in confined fluidized bed based on two-fluid model, applying body-fitted coordination for the irregular geometry zone in this work. The simulation was performed either with a partially packed fluidized bed in the bottom part applying various superficial gas velocities in bubbling region, which is used to study the bubbles formation and the average porosity in the packed zone, or with a whole packed fluidized bed applying various solid flux rates in pneumatic region, which is used to investigate the mechanism in the packed bed. The void fraction of the fine-particles confined bed as a function of flow velocity is compared with experimental results by G. Donsi etc.(1). The numerical pressure drop in the fully packed bed is compared with experimental results by Yulong Ding etc. (2)
Spectrum of malignancies among the population of adults living with HIV infection in China: A nationwide follow-up study, 2008-2011.
BackgroundAlthough increasingly studied in high-income countries, there is a paucity of data from the Chinese population on the patterns of cancer among people living with HIV (PLHIV).MethodsWe conducted a nationwide follow-up study using routinely collected data for adult PLHIV diagnosed on or before 31 December 2011 and alive and in care as of 1 January 2008. Participants were observed from 1 January 2008 (study start) to 30 June 2012 (study end). Main outcome measures were gender-stratified age-standardized incidence rates for China (ASIRC) and standardized incidence ratios (SIR) for all malignancy types/sites observed.ResultsAmong 399,451 subjects, a majority was aged 30-44 years (49.3%), male (69.8%), and Han Chinese (67.9%). A total of 3,819 reports of cancer were identified. Overall, ASIRC was 776.4 per 100,000 for males and 486.5 per 100,000 for females. Malignancy sites/types with highest ASIRC among males were lung (226.0 per 100,000), liver (145.7 per 100,000), and lymphoma (63.1 per 100,000), and among females were lung (66.8 per 100,000), lymphoma (48.0 per 100,000), stomach (47.8 per 100,000), and cervix (47.6 per 100,000). Overall SIR for males was 3.4 and for females was 2.6. Highest SIR was observed for Kaposi sarcoma (2,639.8 for males, 1,593.5 for females) and lymphoma (13.9 for males, 16.0 for females).ConclusionsThese results provide evidence of substantial AIDS-defining and non-AIDS-defining cancer burden among adult Chinese PLHIV between 2008 and 2011. Although further study is warranted, China should take action to improve cancer screening, diagnosis, and treatment for this vulnerable population
Magnetically-accelerated photo-thermal conversion and energy storage based on bionic porous nanoparticles
Recently, the technology of mixing phase change materials with high thermal conductivity fillers was developed, which has allowed thermal energy storage to be implemented in a wide range of industrial technologies and processes. In the present study, a hierarchical bionic porous nano-composite was prepared, which efficiently merged the nanomaterial characteristics of magnetism and high thermal conductivity in order to form a magnetically-accelerated solar-thermal energy storage method. The morphology and thermo-physical properties of materials were analysed. The experimental outcomes of phase change heat transfer demonstrated that the maximum storage efficiency increases by 102.7% when the hierarchical bionic porous structure is used, and a further 27.1% improvement can be achieved with the magnetic field. At the same time, the heat transfer process of energy storage in hierarchical porous composites under external physical fields is explained by simulation. Therefore, this magnetically-accelerated method demonstrated the superior solar-thermal energy storage characteristics within a hierarchical bionic porous structure which is particularly beneficial for the utilisation of solar direct absorption collectors and energy storage technology
Direct numerical simulation of Taylor-Couette flow with vertical asymmetric rough walls
Direct numerical simulations are performed to explore the effects of rotating
direction of the vertical asymmetric rough wall on the transport properties of
Taylor-Couette (TC) flow up to a Taylor number of . It is shown that compared to the smooth wall, the rough wall with
vertical asymmetric strips can enhance the dimensionless torque
\textit{Nu}, and more importantly, at high \textit{Ta} clockwise
rotation of the inner rough wall (the fluid is sheared by the steeper slope
side of the strips) results in a significantly bigger torque enhancement as
compared to the counter-clockwise rotation (the fluid is sheared by the smaller
slope side of the strips) due to the larger convective contribution to the
angular velocity flux, although the rotating direction has a negligible effect
on the torque at low \textit{Ta}. The larger torque enhancement caused by the
clockwise rotation of vertical asymmetric rough wall at high \textit{Ta} is
then explained by the stronger coupling between the rough wall and the bulk due
to the larger biased azimuthal velocity towards the rough wall at the mid-gap
of TC system, the increased intensity of turbulence manifesting by larger
Reynolds stress and thinner boundary layer, and the more significant
contribution of the pressure force on the surface of rough wall to the torque.Comment: 17 pages,11 figure
Accuracy of radiomics in the diagnosis and preoperative high-risk assessment of endometrial cancer: a systematic review and meta-analysis
BackgroundWith the increasing use of radiomics in cancer diagnosis and treatment, it has been applied by some researchers to the preoperative risk assessment of endometrial cancer (EC) patients. However, comprehensive and systematic evidence is needed to assess its clinical value. Therefore, this study aims to investigate the application value of radiomics in the diagnosis and treatment of EC.MethodsPubmed, Cochrane, Embase, and Web of Science databases were retrieved up to March 2023. Preoperative risk assessment of EC included high-grade EC, lymph node metastasis, deep myometrial invasion status, and lymphovascular space invasion status. The quality of the included studies was appraised utilizing the RQS scale.ResultsA total of 33 primary studies were included in our systematic review, with an average RQS score of 7 (range: 5–12). ML models based on radiomics for the diagnosis of malignant lesions predominantly employed logistic regression. In the validation set, the pooled c-index of the ML models based on radiomics and clinical features for the preoperative diagnosis of endometrial malignancy, high-grade tumors, lymph node metastasis, lymphovascular space invasion, and deep myometrial invasion was 0.900 (95%CI: 0.871–0.929), 0.901 (95%CI: 0.877–0.926), 0.906 (95%CI: 0.882–0.929), 0.795 (95%CI: 0.693–0.897), and 0.819 (95%CI: 0.705–0.933), respectively.ConclusionsRadiomics shows excellent accuracy in detecting endometrial malignancies and in identifying preoperative risk. However, the methodological diversity of radiomics results in significant heterogeneity among studies. Therefore, future research should establish guidelines for radiomics studies based on different imaging sources.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=364320 identifier CRD42022364320
DEM Study of Wet Cohesive Particles in the Presence of Liquid Bridges in a Gas Fluidized Bed
A modified discrete element method (DEM) was constructed by compositing an additional liquid-bridge module into the traditional soft-sphere interaction model. Simulations of particles with and without liquid bridges are conducted in a bubbling fluidized bed. The geometry of the simulated bed is the same as the one in Müller’s experiment (Müller et al., 2008). A comparison between the dry and the wet particular systems is carried out on the bubble behavior, the bed fluctuation, and the mixing process. The bubble in the dry system possesses a regular round shape and falling of scattered particles exists while the bubble boundary of the wet particles becomes rough with branches of agglomerates stretching into it. The mixing of the dry system is quicker than that of the wet system. Several interparticle liquid contents are applied in this work to find their influence on the kinetic characteristic of the wet particle flow. With an increase of liquid content, the mixing process costs more time to be completed. Symmetrical profiles of the velocity and granular temperature are found for two low liquid contents (0.001% and 0.01%), while it is antisymmetrical for the highest liquid content (0.1%)
Numerical simulation of natural convection in a square enclosure filled with nanofluid using the two-phase Lattice Boltzmann method
Contribution to the genus Filipinolotis Miyatake, 1994 (Coleoptera, Coccinellidae, Sticholotidini)
The genus Filipinolotis Miyatake has been reviewed in this study. Descriptions and illustrations of two species (F. latefasciata Miyatake and F. purpuratorotunda Wang, Zhang & Ślipiński, sp. n.) in the Luzon island of the Philippines, are given. The male genitalia of F. latefasciata are described for the first time. A key to known species is also provided
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Evolving interest and sense of self in an environmental citizen science program
Citizen science is a growing phenomenon across many branches of environmental science facilitating both increased science literacy and the collection of highly rigorous, longitudinal data. Understanding the motivations of adults to join and remain active in citizen science programs is important as the diversity and abundance of opportunities for public participation in science grow. We conducted a mixed-methods study of newly recruited and “seasoned” (1 year plus) participants in the Coastal Observation and Seabird Survey Team, a hands-on, environmental citizen science program focused on adult coastal residents, to explore the degree to which engagement, measured as time in the program, influenced motivation. We used constructs of functionalism, person-object theory of interest, and activity theoretic approaches to situational identity to deconstruct motivation into three interacting components: objects of interest, actions directed toward those objects, and situated senses of self. Newly recruited participants came with a strong interest in being outside on the beach and learning about birds and saw themselves as data collectors defined in part by their birding and degree/job-based credentials and their social relationships. By contrast, seasoned participants aligned their interests and situational identity more directly with the program, calling out the importance of program data and results, elevating science-based actions such as monitoring over learning, intensifying their desire to contribute to science, subjugating individual attributes in favor of their science identity, and increasing their sense of self-worth attached to the project. Our results suggest that hands-on, environmental citizen science programs focused on adults should shape their data collector roles and projects around context-specific motivations including senses of place and biodiversity, support both the altruistic and self-interest needs of participants, and combine rigorous science experience with social interaction
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