Isotropic-nematic phase equilibria in the Onsager theory of hard rods with length polydispersity

We analyse the effect of a continuous spread of particle lengths on the phase behavior of rodlike particles, using the Onsager theory of hard rods. Our aim is to establish whether ``unusual'' effects such as isotropic-nematic-nematic (I-N-N) phase separation can occur even for length distributions with a single peak. We focus on the onset of I-N coexistence. For a log-normal distribution we find that a finite upper cutoff on rod lengths is required to make this problem well-posed. The cloud curve, which tracks the density at the onset of I-N coexistence as a function of the width of the length distribution, exhibits a kink; this demonstrates that the phase diagram must contain a three-phase I-N-N region. Theoretical analysis shows that in the limit of large cutoff the cloud point density actually converges to zero, so that phase separation results at any nonzero density; this conclusion applies to all length distributions with fatter-than-exponentail tails. Finally we consider the case of a Schulz distribution, with its exponential tail. Surprisingly, even here the long rods (and hence the cutoff) can dominate the phase behaviour, and a kink in the cloud curve and I-N-N coexistence again result. Theory establishes that there is a nonzero threshold for the width of the length distribution above which these long rod effects occur, and shows that the cloud and shadow curves approach nonzero limits for large cutoff, both in good agreement with the numerical results.Comment: 20 pages, 13 figure

Prime Focus Spectrograph - Subaru's future -

The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 {\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving power of 3000. Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil, Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and NAOJ/Subaru.Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki Takami, Editors, Proc. SPIE 8446 (2012)

Beyond feedback: introducing the 'engagement gap' in organizational energy management

This paper discusses socio-technical relationships between people, organizations and energy in workplaces. Inspired by Sherry Arnstein’s ladder of citizen participation, it explores widening energy management beyond energy managers to other employees, introducing the idea of an ‘engagement gap’ to support a move beyond unidirectional forms of engagement (e.g. feedback and nudging) to more socially interactive processes. Results are drawn from two projects researching energy practices in public authorities and retail organizations. The first project, ‘GoodDeeds’, collaboratively created an information and communication technology tool and explored participatory processes within a municipality. The second project, Working with Infrastructure, Creation of Knowledge, and Energy strategy Development (WICKED), explored energy management in retail companies. The paper uses a ‘4Cs’ framework to articulate the influences of concerns, capacities and technical conditions within organizational communities. The results concur with previous research that energy management sits against a backdrop of competing organizational, institutional and political concerns. New data reveal discrepancies across organizations with regard to energy management capacities and technical metering conditions. The authors suggest employee engagement can be broadened by treating energy as a communal subject for discussion, negotiation and partnership. This objective moves beyond the ‘information-deficit’ approach intrinsic in the existing focus on analytics, dashboards and feedback

Systems thinking : an approach for understanding 'eco-agri-food systems'

The TEEBAgriFood ‘Scientific and Economic Foundations’ report addresses the core theoretical issues and controversies underpinning the evaluation of the nexus between the agri-food sector, biodiversity and ecosystem services and externalities including human health impacts from agriculture on a global scale. It argues the need for a ‘systems thinking‘ approach, draws out issues related to health, nutrition, equity and livelihoods, presents a Framework for evaluation and describes how it can be applied, and identifies theories and pathways for transformational change

Complex Reorganization and Predominant Non-Homologous Repair Following Chromosomal Breakage in Karyotypically Balanced Germline Rearrangements and Transgenic Integration

We defined the genetic landscape of balanced chromosomal rearrangements at nucleotide resolution by sequencing 141 breakpoints from cytogenetically-interpreted translocations and inversions. We confirm that the recently described phenomenon of “chromothripsis” (massive chromosomal shattering and reorganization) is not unique to cancer cells but also occurs in the germline where it can resolve to a karyotypically balanced state with frequent inversions. We detected a high incidence of complex rearrangements (19.2%) and substantially less reliance on microhomology (31%) than previously observed in benign CNVs. We compared these results to experimentally-generated DNA breakage-repair by sequencing seven transgenic animals, and revealed extensive rearrangement of the transgene and host genome with similar complexity to human germline alterations. Inversion is the most common rearrangement, suggesting that a combined mechanism involving template switching and non-homologous repair mediates the formation of balanced complex rearrangements that are viable, stably replicated and transmitted unaltered to subsequent generations

Systemic action research, turbulence and emergence

Purpose - In this chapter the author draws on a number of his personal experiences of turbulence in the world about him, to illustrate how he came to embrace principles and practices of systemic action research/systemic development in his efforts to more successfully deal with the complex uncertainties and chaotic disorder of surroundings in which he has found himself. Design - The nature of systemic action research is presented along with a description of how that was expressed as praxis during a long-term initiative in the transformation of an educational institution in Australia that reflected the response of a group of academics to severe turbulence in the world about them. The characteristics of the 'system idea' that were fundamental to this work are discussed, and their significance to turbulence as an emergent property are explored. Findings - These conceptualizations are woven into a somewhat autoethnographic narrative of personal transformation in the face of extreme turbulence. In the manner entirely consistent with the key systems concepts of 'emergence' and diversity, the story itself illustrates the various motivations for, and a continuing momentum of, this fusion of systems concepts and principles with action researching practices. Challenges presented by environmental turbulence have been met with deliberate attention to and appreciation of the dialectic relationship between shared experiences in the 'concrete world' and the collective generation of 'abstract knowledge'. Value - It is the knowledge that has 'emerged' in this manner that has then been used to inform responsible sustainable actions for development

Extension as critical learning : a systemic response to the global challenge

Very significant inter-relationships exist between the way we humans view the world about us-the perspective we hold about it, if you will-and how we treat that world in terms of what we do to it in the pursuit of our human activities. Essentially we might describe the relationship as recursive: mutually influential. Just as what we see in this world markedly influences what we do in it, so too does what we do in it, markedly influence the way we tend to see it

Reflections on the action of reflections in action : of cars, helicopters and satellites

I have long been dissatisfied with the emphasis on reflection as a process of reviewing after the event- you think, you do, and then you think of what you just thought and of what you just did, ex post facto. For me, this is a this is a very limited construction of the process of thinking about thinking and doing. We can, and should extend the concept considerably. Of particular importance, I believe is to capture the dynamic essence of reflecting on what you are thinking and what you are doing, as you are thinking and doing it! Donald Schoen (1987, 26) gives us the lead: We may reflect on action, thinking back on what we have done ... or we may pause in the midst of action to make what Hannah Arendt (1971) calls a 'stop and think'. I either case, our reflection has no direct connection to present action. Alternatively, we may reflect in the midst of action without interrupting it ... I shall say in cases like this, that we reflect in action. I want to pursue this notion of reflection-in-action as a way of knowing and, indeed, present it in the context of knowing about knowing

Fred Emery Oration : systems thinking (and action) FROM the new millennium : learning from the future

Fred Emery, was an amazingly perceptive and prescient systems scientist, who was, without a shadow of a doubt, the father of the systems movement down here in the antipodes, to which he returned in the 1970s after a very distinguished career at the Tavistock Research Institute in London. He had a prime interest in the nature of work and in particular in how people organised themselves and the machines and other resources with which they worked, to achieve their goals and maintain their ideals and values, in the face of what he recognised as often “turbulent environments”. I first met him at the Australian National University soon after his return, when I was involved as a participant in one of his Search Conferences. His was an unforgettable illustration of theory in practice, walking his talk with all the confidence that long experience and scholarship together can bring. Over subsequent years, our paths would cross from time to time, either in the context of other Searches, or in dialogue about systems education, which was a topic about which, it would be fair to say, we both had obsessive tendencies