324 research outputs found

    Effects of Strong Gravitational Lensing on Millimeter-Wave Galaxy Number Counts

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    We study the effects of strong lensing on the observed number counts of mm sources using a ray tracing simulation and two number count models of unlensed sources. We employ a quantitative treatment of maximum attainable magnification factor depending on the physical size of the sources, also accounting for effects of lens halo ellipticity. We calculate predicted number counts and redshift distributions of mm galaxies including the effects of strong lensing and compare with the recent source count measurements of the South Pole Telescope (SPT). The predictions have large uncertainties, especially the details of the mass distribution in lens galaxies and the finite extent of sources, but the SPT observations are in good agreement with predictions. The sources detected by SPT are predicted to largely consist of strongly lensed galaxies at z>2. The typical magnifications of these sources strongly depends on both the assumed unlensed source counts and the flux of the observed sources

    Maximum power extraction from wind turbines using a fault-tolerant fractional-order nonsingular terminal sliding mode controller

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    This work presents a nonlinear control approach to maximise the power extraction of wind energy conversion systems (WECSs) operating below their rated wind speeds. Due to nonlinearities associated with the dynamics of WECSs, the stochastic nature of wind, and the inevitable presence of faults in practice, developing reliable fault-tolerant control strategies to guarantee maximum power production of WECSs has always been considered important. A fault-tolerant fractional-order nonsingular terminal sliding mode control (FNTSMC) strategy to maximize the captured power of wind turbines (WT) subjected to actuator faults is developed. A nonsingular terminal sliding surface is proposed to ensure fast finite-time convergence, whereas the incorporation of fractional calculus in the controller enhances the convergence speed of system states and simultaneously suppresses chattering, resulting in extracted power maximisation by precisely tracking the optimum rotor speed. Closed-loop stability is analysed and validated through the Lyapunov stability criterion. Comparative numerical simulation analysis is carried out on a two-mass WT, and superior power production performance of the proposed method over other methods is demonstrated, both in fault-free and faulty situations

    Digital leadership and organizational capabilities in manufacturing industry: A study in Malaysian context

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    The research is conducted to study the outcome of digital leadership on dynamic capabilities, innovation capabilities, and alliances capabilities in manufacturing industries within the Malaysian context. Today, developing corporations and industries, at the least, require a virtual transformation to have greater organisational abilities in shaping and growing their new and present commercial enterprise to healthy the brand-new generation paradigm. A cross-sectional quantitative method has been used in this study with a sample of 132 respondents with different industry back grounds. These respondents are organisations, which are based on the nature of a business role like authorised representative, distributor, importer, manufacturer, combination authorised representative, distributor and importer, and combination distributor and importer that located in Selangor, Malaysia. The research used the SMART PLS software to analyse and interpret the results. There main hypotheses are proposed and tested. The results showed that digital leadership positively affects dynamic capabilities, innovation capabilities, and alliances capabilities

    Detection of lensing substructure using ALMA observations of the dusty galaxy SDP.81

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    We study the abundance of substructure in the matter density near galaxies using ALMA Science Verification observations of the strong lensing system SDP.81. We present a method to measure the abundance of subhalos around galaxies using interferometric observations of gravitational lenses. Using simulated ALMA observations, we explore the effects of various systematics, including antenna phase errors and source priors, and show how such errors may be measured or marginalized. We apply our formalism to ALMA observations of SDP.81. We find evidence for the presence of a M=108.96±0.12MM=10^{8.96\pm 0.12} M_{\odot} subhalo near one of the images, with a significance of 6.9σ6.9\sigma in a joint fit to data from bands 6 and 7; the effect of the subhalo is also detected in both bands individually. We also derive constraints on the abundance of dark matter subhalos down to M2×107MM\sim 2\times 10^7 M_{\odot}, pushing down to the mass regime of the smallest detected satellites in the Local Group, where there are significant discrepancies between the observed population of luminous galaxies and predicted dark matter subhalos. We find hints of additional substructure, warranting further study using the full SDP.81 dataset (including, for example, the spectroscopic imaging of the lensed carbon monoxide emission). We compare the results of this search to the predictions of Λ\LambdaCDM halos, and find that given current uncertainties in the host halo properties of SDP.81, our measurements of substructure are consistent with theoretical expectations. Observations of larger samples of gravitational lenses with ALMA should be able to improve the constraints on the abundance of galactic substructure.Comment: 18 pages, 13 figures, Comments are welcom

    Spectroscopy of CASSOWARY gravitationally-lensed galaxies in SDSS: characterisation of an extremely bright reionization-era analog at z=1.42z=1.42

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    We present new observations of sixteen bright (r=1921r=19-21) gravitationally lensed galaxies at z13z\simeq 1-3 selected from the CASSOWARY survey. Included in our sample is the z=1.42z=1.42 galaxy CSWA-141, one of the brightest known reionization-era analogs at high redshift (g=20.5), with a large sSFR (31.2 Gyr1^{-1}) and an [OIII]+Hβ\beta equivalent width (EW[OIII]+Hβ_{\rm{[OIII]+H\beta}}=730~\r{A}) that is nearly identical to the average value expected at z78z\simeq 7-8. In this paper, we investigate the rest-frame UV nebular line emission in our sample with the goal of understanding the factors that regulate strong CIII] emission. Whereas most of the sources in our sample show weak UV line emission, we find elevated CIII] in the spectrum of CSWA-141 (EWCIII]_{\rm{CIII]}}=4.6±1.9\pm1.9~\r{A}) together with detections of other prominent emission lines (OIII], Si III], Fe II^\star, Mg II). We compare the rest-optical line properties of high redshift galaxies with strong and weak CIII] emission, and find that systems with the strongest UV line emission tend to have young stellar populations and nebular gas that is moderately metal-poor and highly ionized, consistent with trends seen at low and high redshift. The brightness of CSWA-141 enables detailed investigation of the extreme emission line galaxies which become common at z>6z>6. We find that gas traced by the CIII] doublet likely probes higher densities than that traced by [OII] and [SII]. Characterisation of the spectrally resolved Mg II emission line and several low ionization absorption lines suggests neutral gas around the young stars is likely optically thin, potentially facilitating the escape of ionizing radiation.Comment: 20 pages, 9 figures, Accepted for publication in MNRA

    Quality of Life and Autonomy in Emerging Adults with Early‐Onset Neuromuscular Disorders

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    Emerging adulthood is an important period in the development of one’s identity and autonomy. The ways in which identity and autonomy are viewed by emerging adults and how they impact quality of life (QoL) in individuals with early‐onset neuromuscular conditions is not yet known. This study focused on understanding and exploring relationships between self‐perceptions of emerging adulthood, autonomy, and QoL. Five previously validated measures were incorporated into an online survey and distributed to young adults with early‐onset neuromuscular conditions and unaffected controls. Topics explored included individuals’ views regarding their overall QoL, disease‐specific QoL, components of emerging adulthood, and autonomy. We found that a sense of higher disease impact was associated with a lower Overall General QoL. Additionally, perceptions of key autonomy factors “negativity” and “instability” were uniquely associated with Overall General QoL in the case group as compared to controls, whereas “attitudinal autonomy” (attaining the ability to plan and follow through with goals) was important to this age group regardless of health status. The specific factors of emerging adulthood and autonomy that were significantly correlated with Overall General QoL can be used for developing targeted counseling and interventions to improve QoL for individuals and their families.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146967/1/jgc40713.pd

    Family Communication in a Population at Risk for Hypertrophic Cardiomyopathy

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    Encouraging family communication is an integral component of genetic counseling; therefore, we sought to identify factors impacting communication to family members at risk for Hypertrophic Cardiomyopathy (HCM). Participants (N = 383) completed an online survey assessing: 1) demographics (gender, genetic test results, HCM family history, and disease severity); 2) illness representations; 3) family functioning and cohesiveness; 4) coping styles; 5) comprehension of HCM autosomal dominant inheritance; and 6) communication of HCM risk information to at‐risk relatives. Participants were a national sample of individuals with HCM, recruited through the Hypertrophic Cardiomyopathy Association. Data from 183 participants were analyzed using a logistic regression analysis, with family communication as a dichotomous dependent variable. We found that female gender and higher comprehension of autosomal dominant inheritance were significant predictors of participants’ communication of HCM risk information to all their siblings and children. Our results suggest that utilizing interventions that promote patient comprehension (e.g., a teaching‐focused model of genetic counseling) are important and may positively impact family communication within families with HCM.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147017/1/jgc40336.pd
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