507 research outputs found

    Measurement of Charge Distributions in a Bubbling Fluidized Bed Using Wire-Mesh Electrostatic Sensors

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    In order to maintain safe and efficient operation of a fluidized bed, electrostatic charges in the bed should be monitored continuously. Electrostatic sensors with wire-mesh electrodes are introduced in this paper to measure the charge distribution in the cross section of the fluidized bed. A Finite Element Model is built to investigate the sensing characteristics of the wire-mesh sensors. In comparison with conventional electrostatic sensors, wire-mesh sensors have higher and more uniform sensitivity distribution. Based on the induced charges on the electrodes and the sensitivity distributions of the sensors, the charge distribution in the cross section of the fluidized bed is reconstructed. However, it is difficult to directly measure the induced charges on the electrodes. A charge calibration process is conducted to establish the relationship between the induced charge on the electrode and the electrostatic signal. Experimental studies of charge distribution measurement were conducted on a lab-scale bubbling fluidized bed. The electrostatic signals from the wire-mesh sensors in the dense phase and splash regions of the bed for different fluidization air flow rates were obtained. Based on the results obtained from the charge calibration process, the estimated induced charges on the electrodes are calculated from the Root Mean Square values of the electrostatic signals. The characteristics of the induced charges on the electrodes and the charge distribution in the cross section under different flow conditions are investigated, which proves that wire-mesh electrostatic sensors are able to measure the charge distribution in the bubbling fluidized bed

    Leaders’ response to employee overqualification:An explanation of the curvilinear moderated relationship

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    This research aimed to advance overqualification literature by examining how leaders’ perceived employee overqualification (LPEO) influences their empowering behaviour and employee work behaviours. Drawing upon the individualized leadership theory, we proposed that LPEO has an inverted U-shape relationship with their empowering behaviour such that leaders are more motivated to empower employees from low to moderate levels of overqualification, but this tendency decreases after a certain inflection point. We also predicted that the inflection point occurs at a lower level of employee overqualification when leaders perceive higher (vs. lower) status threats. Leader empowering behaviour was hypothesized to positively predict employees’ voice and negatively predict their withdrawal behaviour. Two multi-source and time-lagged studies were conducted to examine this moderated mediation curvilinear model. In Study 1, survey data from 372 leader–employee dyads supported the inverted U-shape mediation model from leaders’ perceived overqualification to empowering behaviour, then to employee outcomes (i.e., voice and withdrawal behaviour). In Study 2, we collected data from a sample of 73 team leaders and 286 employees, and the results supported the full model. Taken together, these findings offer a perspective to enrich the understanding of employee overqualification and have important practical implications.Practitioner pointsWhen leaders regard employees as overqualified, they can assist them via the means of appropriate empowerment to best utilize their skills to benefit the company.Leader empowerment can inspire employees’ voice behaviour but reduce their withdrawal behaviours.To minimize potentially negative aspects from highly overqualified employees, organizations should reduce leaders’ concern about the status threat, and encourage leaders’ proactive responses to these employees so as to achieve positive returns from overqualified employees

    Leaders’ response to employee overqualification:An explanation of the curvilinear moderated relationship

    Get PDF
    This research aimed to advance overqualification literature by examining how leaders’ perceived employee overqualification (LPEO) influences their empowering behaviour and employee work behaviours. Drawing upon the individualized leadership theory, we proposed that LPEO has an inverted U-shape relationship with their empowering behaviour such that leaders are more motivated to empower employees from low to moderate levels of overqualification, but this tendency decreases after a certain inflection point. We also predicted that the inflection point occurs at a lower level of employee overqualification when leaders perceive higher (vs. lower) status threats. Leader empowering behaviour was hypothesized to positively predict employees’ voice and negatively predict their withdrawal behaviour. Two multi-source and time-lagged studies were conducted to examine this moderated mediation curvilinear model. In Study 1, survey data from 372 leader–employee dyads supported the inverted U-shape mediation model from leaders’ perceived overqualification to empowering behaviour, then to employee outcomes (i.e., voice and withdrawal behaviour). In Study 2, we collected data from a sample of 73 team leaders and 286 employees, and the results supported the full model. Taken together, these findings offer a perspective to enrich the understanding of employee overqualification and have important practical implications.Practitioner pointsWhen leaders regard employees as overqualified, they can assist them via the means of appropriate empowerment to best utilize their skills to benefit the company.Leader empowerment can inspire employees’ voice behaviour but reduce their withdrawal behaviours.To minimize potentially negative aspects from highly overqualified employees, organizations should reduce leaders’ concern about the status threat, and encourage leaders’ proactive responses to these employees so as to achieve positive returns from overqualified employees

    Dependency of the combustion behavior of energy grass and three other types of biomass upon lignocellulosic composition

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    The combustion characteristics of four kinds of biomass fuels (energy grass, sawdust, corn cob, and walnut shell) are investigated in this article. All the samples are heated from room temperature to 800°C at multiple heating rates of 10, 20, and 30°C/min. The effect of hemicellulose, cellulose, and lignin components on the pyrolysis and combustion processes of energy grass is explored by comparison to those of the other three types of biomass. The hemicellulose and cellulose content of samples could improve the devolatilization performance during biomass combustion. Furthermore, the comprehensive combustion index suggested herein indicates that the combustion performance of energy grass or walnut shell is limited by their high ash content or their low ratio of cellulose to lignin. Kinetic parameters are obtained by combining the isoconversional method (OFW and KAS models) and the method of master-plots. The apparent activation energy of the devolatilization stage is higher than that of the char oxidization stage, which is mainly influenced by the lignocellulosic composition

    The "double-edged sword" effects of career support mentoring on newcomer turnover: How and when it helps or hurts.

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    Research on mentoring programs has portrayed them almost exclusively beneficial for newcomer retention. Drawing from the social cognitive model of career management and the boundaryless career perspective, we depart from this predominant view and examine the "double-edged sword" effects of career support mentoring on newcomer turnover. We propose that career support mentoring received by newcomers is likely to elicit both internal proactive socialization and external career self-management, which act as countervailing forces driving newcomer turnover in opposite directions (i.e., the retention pathway and the unintended detrimental pathway). We further propose that the organizational role of the mentor-supervisor versus nonsupervisor-is critical in determining which pathway prevails. We conducted two multiwave newcomer studies to test our hypotheses. In Study 1 ( = 495), we found that received career support mentoring was associated with lower newcomer turnover probability through the serial mediation of internal proactive socialization and perceived internal marketability but higher newcomer turnover probability through the serial mediation of external career self-management and perceived external marketability. In Study 2 ( = 193), we found that received career support mentoring was associated with lower newcomer turnover intention through the serial mediation of internal career advancement expectation and internal proactive socialization but higher newcomer turnover intention through the serial mediation of external career advancement expectation and external career self-management. In both studies, the unintended detrimental pathway was significant only when a newcomer's mentor was not a supervisor. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

    Distressed yet bonded: A longitudinal investigation of the COVID-19 pandemic’s silver lining effects on life satisfaction.

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    It is a common understanding that the 2019 coronavirus pandemic (COVID-19) significantly harmed mental health. However, findings on changes in overall life satisfaction have been mixed and inconclusive. To address this puzzling phenomenon, we draw upon the domain specific perspective of well-being and research on catastrophe compassion and propose thatthe pandemic can have opposing effects on mental health and communal satisfaction, which then differently relate to people’s overall life satisfaction. Longitudinal analyses of the Household, Income and Labour Dynamics (HILDA) Survey of Australia (N = 12,093) showed that while there was a greater decrease in mental health in the first COVID-19 pandemic year (2019-2020) than in previous years (2017-2019), an increase in communal satisfaction also occurred, demonstrating a potential silver lining effect of the pandemic on people’s satisfaction with family, community and neighborhood. Moreover, consistent with socioemotional selectivity theory, changes in mental health, communal satisfaction and life satisfaction were related to age such that older adults generally reported less harmful and more beneficial psychological changes. We further found that age was associated with stronger associations of mental health and communal satisfaction with life satisfaction during the pandemic year. Overall, our findings speak to the importance of communal life in life satisfaction during the pandemic and age-related differences in the process, shedding light on the need to devise customized support to address inequalities in pandemic effects on public well-being

    Novel process of coating Al on graphene involving organic aluminum accompanying microstructure evolution

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    A novel chemical reduction of organic aluminum for coating Al on the graphene surface is proposed. During the process, Al powder reacted with the (C2H5)2Br solution to produce (C2H5)3Al solution, followed by gradual decomposition of (C2H5)3Al into Al atoms. Al atoms gradually deposited on the surface of graphene, nucleated, grew up, until Al coating was formed on the surface of graphene. With the increase of reaction temperature, the decomposition rate of (C2H5)3Al increased, which was beneficial to the formation of Al atoms and Al coating. The reducing agent, NaH, promoted the reaction and formation of Al coating. When the reaction temperature was optimized to 100 °C, and the reaction time was 1.5 h, with NaH added to the solution, high quality Al-coated graphene was obtained.acceptedVersion© 2018. This is the authors’ accepted and refereed manuscript to the article. Locked until 7.08.2020 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

    Histone ubiquitination-related gene CUL4B promotes lung adenocarcinoma progression and cisplatin resistance

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    Background: The role of the histone ubiquitination-related gene in the cisplatin resistance of lung adenocarcinoma (LUAD) remains an intricate subject.Methods: We accessed transcriptome data of both wild type and cisplatin-resistant cells from the GSE108214 dataset, and garnered transcriptome and clinical data of LUAD patients from The Cancer Genome Atlas (TCGA) database. Utilizing the R software, we analyzed these public datasets in depth. Real-time Quantitative PCR (qPCR) was used to detect the RNA level of CUL4B. Effect of CUL4B on cell proliferation was evaluated using CCK8 and colony formation assay. Effect of CUL4B on cell invasion was evaluated using transwell assay. Cisplatin sensitivity was evaluated by calculating IC50.Results: Our analysis shed light on the significance of the histone ubiquitination-related gene, CUL4B, in relation to cisplatin resistance and the overall survival rates of LUAD patients. Notably, CUL4B was found to be overexpressed in both lung cancer tissues and cells. Meanwhile, in vitro experiments indicated can CUL4B significantly promote the proliferation, invasion and migration of lung cancer cells. Furthermore, suppressing CUL4B expression led to a noticeable reduction in the IC50 value of cisplatin in lung cancer cells. A deep dive into biological enrichment analysis revealed that among patients exhibiting high CUL4B expression, there was a pronounced activation of the G2M checkpoint and the PI3K/AKT/mTOR signaling pathways. Immune microenvironment analysis has revealed that patients with elevated CUL4B expression may exhibit increased infiltration of M2 macrophages, coupled with a reduced infiltration of CD8+ T cells and activated NK cells. Notably, we observed higher CUL4B expression among those who responded positively to immunotherapy.Conclusion: These findings underscore the significance of CUL4B in the resistance to cisplatin in lung cancer, highlighting its potential as a therapeutic target
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