Managing the accountability-autonomy tensions in university research commercialisation

This article investigates organisational responses to emerging concerns about how accountability–autonomy tensions can be managed within the context of university research commercialisation. The findings suggest that changed expectations of university research practices, which result from the introduction of a commercialisation logic, can be managed via the homogenisation of research goals and strategies. The successful management of accountability–autonomy tensions also depends on utilising the various structures and cultural contexts that can be facilitated by decoupling and bridging strategies. Further, while adopting symbolic systems may enhance legitimacy, failure to implement material practices and provide the appropriate cultural context to manage conflicting relationships may put university commercialisation ambitions at risk

Transient downflows associated with the intensification of small-scale magnetic features and bright point formation

Small-scale magnetic features are present everywhere in the solar photosphere. Theoretical models, numerical calculations, and simulations describing the formation of these features have existed for a few decades, but there are only a few observational studies in direct support of the simulations. In this study we present the evolution of small-scale magnetic features with a spatial resolution close to 0.15 arcsecond and compare these observations with those predicted by numerical simulations and also with previous observational work of a similar nature. We analyze a 40 min time sequence of full Stokes spectropolarimetric 630.25 nm data from a plage region near the Sun center. We use line-of-sight velocities and magnetic field measurements obtained using Milne-Eddington inversion techniques with and without stray-light compensation along with measured continuum and line minimum intensities. We discuss the results in relation to earlier observations and simulations. We present eight cases involving strong downflows and magnetic field intensification. All cases studied are associated with the formation of a bright point in the continuum. In three out of the eight cases we find the presence of weak opposite polarity field in close proximity to the downflow. Our data are consistent with earlier simulations describing flux tube collapse, but the transition to a state with stronger field appears transient and short-lived, rather than resulting in a permanent field intensification. Three cases of weak opposite polarity field found adjacent to the downflows do not appear related to reconnection but may be related to overturning convection pulling down some field lines and leading to up/down "serpentine" field, as seen in some simulations.Comment: Accepted for publication in Astronomy & Astrophysic

Microflares in accretion disks

We have investigated the phenomenon of explosive chromospheric evaporation from an accretion disk as a mechanism for fast variability in accreting sources such as low mass X-ray binaries and active galactic nuclei. This has been done in the context of advection dominated accretion flows, allowing both high and low states to be considered. This mechanism can in principle produce sub-millisecond timescales in binaries and sub-minute timescales in active galaxies. However, even considering the possibility that large numbers of these microflares may be present simultaneously, the power emitted from these microflares probably amounts to only a small fraction of the total X-ray luminosity.Comment: 5 pages, 1 figure, uses older A&A class file; accepted for publication in A&

Hydrodynamical winds from two-temperature plasma in X-ray binaries

Hydrodynamical winds from a spherical two-temperature plasma surrounding a compact object are constructed. The mass-loss rate is computed as a function of electron temperature, optical depth and luminosity of the sphere, the values of which can be constrained by the fitting of the spectral energy distributions for known X-ray binary systems. The sensitive dependence of the mass loss rate with these parameters leads to the identification of two distinct regions in the parameter space separating wind-dominated from non wind dominated systems. A critical optical depth, tau_c, as a function of luminosity and electron temperature, is defined which differentiates these two regions. Systems with optical depths significantly smaller than tau_c are wind-dominated. The results are applied to black hole candidate X-ray binary systems in the hard spectral state (Cyg X-1, GX 339-4 and Nova Muscae), and it is found that the inferred optical depth (tau) is similar to tau_c suggesting that they are wind regulated systems. On the other hand, for X-ray binary systems containing a neutron star (e.g., Cyg X-2) tau is much larger than tau_c indicating the absence of significant hydrodynamical winds.Comment: 9 pages, 4 figures, Accepted for publication in MNRA

Mass Accretion Rate of Rotating Viscous Accretion Flow

The mass accretion rate of transonic spherical accretion flow onto compact objects such as black holes is known as the Bondi accretion rate(Mdot_B), which is determined only by the density and the temperature of gas at the outer boundary. But most work on disc accretion has taken the mass flux to be a given with the relation between that parameter and external conditions left uncertain. Within the framework of a slim alpha disk, we have constructed global solutions of the rotating, viscous hot accretion flow and determined its mass accretion rate as a function of density, temperature, and angular momentum of gas at the outer boundary. We find that the low angular momentum flow resembles the spherical Bondi flow and its mass accretion rate approaches the Bondi accretion rate for the same density and temperature at the outer boundary. The high angular momentum flow on the other hand is the conventional hot accretion disk with advection, but its mass accretion rate can be significantly smaller than the Bondi accretion rate with the same boundary conditions. We also find that when the temperature at the outer boundary is equal to the virial temperature, solutions exist only for 0.05 ~< mdot ~< 1 when alpha=0.01 where mdot==Mdot/Mdot_B. We also find that the dimensionless mass accretion rate is roughly independent of the radius of the outer boundary but inversely proportional to the angular momentum at the outer boundary and proportional to the viscosity parameter, mdot ~= 9.0 alpha/lambda when 0.1 ~< mdot ~< 1, where the dimensionless angular momentum measure lambda == l_out/l_B is the specific angular momentum of gas at the outer boundary l_out in units of l_B == GM/c_{s,out}, and $c_{s,out}$ the isothermal sound speed at the outer boundary.Comment: 15 pages, 3 figures, to appear in Ap

Physics of the Galactic Center Cloud G2, on its Way towards the Super-Massive Black Hole

The origin, structure and evolution of the small gas cloud, G2, is investigated, that is on an orbit almost straight into the Galactic central supermassive black hole (SMBH). G2 is a sensitive probe of the hot accretion zone of Sgr A*, requiring gas temperatures and densities that agree well with models of captured shock-heated stellar winds. Its mass is equal to the critical mass below which cold clumps would be destroyed quickly by evaporation. Its mass is also constrained by the fact that at apocenter its sound crossing timescale was equal to its orbital timescale. Our numerical simulations show that the observed structure and evolution of G2 can be well reproduced if it formed in pressure equilibrium with the surrounding in 1995 at a distance from the SMBH of 7.6e16 cm. If the cloud would have formed at apocenter in the 'clockwise' stellar disk as expected from its orbit, it would be torn into a very elongated spaghetti-like filament by 2011 which is not observed. This problem can be solved if G2 is the head of a larger, shell-like structure that formed at apocenter. Our numerical simulations show that this scenario explains not only G2's observed kinematical and geometrical properties but also the Br_gamma observations of a low surface brightness gas tail that trails the cloud. In 2013, while passing the SMBH G2 will break up into a string of droplets that within the next 30 years mix with the surrounding hot gas and trigger cycles of AGN activity.Comment: 22 pages, 13 figures, submitted to Ap

Thermodynamic Balancing of the Humidification Dehumidification Desalination System by Mass Extraction and Injection

Humidification dehumidification (HDH) is a promising technology for small scale seawater desalination and has received widespread attention in recent years. The biggest roadblock to commercialization of this technology is its relatively high energy consumption. In this paper, we propose thermodynamic balancing of the humidifier or the dehumidifier through mass extraction and injection as a potential means of reducing the energy consumption of these systems. Balancing minimizes the entropy generation caused by imbalance in driving temperature and concentration differences. We outline a procedure to model the system, using on-design component variables, such that continuous or discrete extraction and/or injection of air from the humidifier to the dehumidifier or vice versa can be analyzed. We present an extraction profile (mass flow rate ratio versus non-dimensional position) in the dehumidifier and the humidifier for attaining close to complete thermodynamic reversibility in an HDH system with a 100% effective humidifier and dehumidifier. Further, we have examined in detail the effect of having finite-sized systems, of balancing the humidifier versus the dehumidifier, and that of the number of extractions.Center for Clean Water and Clean Energy at MIT and KFUPM (Project R4-CW-08)United States. Dept. of State (International Fulbright Science & Technology Award

The Psychiatrization of Poverty: Rethinking the Mental Health-Poverty Nexus

The positive association between ‘mental illness’ and poverty is one of the most well established in psychiatric epidemiology. Yet, there is little conclusive evidence about the nature of this relationship. Generally, explanations revolve around the idea of a vicious cycle, where poverty may cause mental ill health, and mental ill health may lead to poverty. Problematically, much of the literature overlooks the historical, social, political, and cultural trajectories of constructions of both poverty and ‘mental illness’. Laudable attempts to explore the social determinants of mental health sometimes take recourse to using and reifying psychiatric diagnostic categories that individualize distress and work to psychiatrically reconfigure ‘symptoms’ of oppression, poverty, and inequality as ‘symptoms’ of ‘mental illness’. This raises the paradoxical issue that the very tools that are used to research the relationship between poverty and mental health may prevent recognition of the complexity of that relationship. Looking at the mental health–poverty nexus through a lens of psychiatrization (intersecting with medicalization, pathologization, and psychologization), this paper recognizes the need for radically different tools to trace the messiness of the multiple relationships between poverty and distress. It also implies radically different interventions into mental health and poverty that recognize the landscapes in which lived realities of poverty are embedded, the political economy of psychiatric diagnostic and prescribing practices, and ultimately to address the systemic causes of poverty and inequality

Small-scale convection signatures associated with strong plage solar magnetic field

In this work, we study and quantify properties of strong-field small-scale convection and compare observed properties with those predicted by numerical simulations. We analyze spectropolarimetric 630.25 nm data from a unipolar ephemeral region near sun center. We use line-of-sight velocities and magnetic field measurements obtained with Milne-Eddington inversion techniques along with measured continuum intensities and Stokes V amplitude asymmetry at a spatial resolution of 0.15 arcseconds to establish statistical relations between the measured quantities. We also study these properties for different types of distinct magnetic features, such as micropores, bright points, ribbons, flowers and strings. We present the first direct observations of a small-scale granular magneto-convection pattern within extended regions of strong (more than 600 G average) magnetic field. Along the boundaries of the flux concentrations we see mostly downflows and asymmetric Stokes V profiles, consistent with synthetic line profiles calculated from MHD simulations. We note the frequent occurrence of bright downflows along these boundaries. In the interior of the flux concentrations, we observe an up/down flow pattern that we identify as small-scale magnetoconvection, appearing similar to that of field-free granulation but with scales 4 times smaller. Measured RMS velocities are 70% of those of nearby field-free granulation, even though the average radiative flux is not reduced. The interiors of these flux concentrations are dominated by upflows.Comment: Accepted for publication in Astronomy and Astrophysic