Binary fluid amplifier solves stability and load problems

Digital fluid amplifier has load intensity, high stability, and operates at low reynolds numbers. It contains specially designed nozzles to provide uniform exit-velocity profiles and to ensure jets of low turbulence

Fate of the inert three-flavor, spin-zero color-superconducting phases

I investigate some of the inert phases in three-flavor, spin-zero color-superconducting quark matter: the CFL phase (the analogue of the B phase in superfluid $^3\rm He$), the A and A* phases, and the 2SC and sSC phases. I compute the pressure of these phases with and without the neutrality condition. It is shown that the 2SC phase is identical to the A* phase up to a color rotation. The CFL phase is the energetically favored phase except for a small region of intermediate densities where the 2SC/A* phase is favored.Comment: 9 pages, 1 figure; the version accepted to publish in PR

The genomes and history of domestic animals

This paper reviews how mammalian genomes are utilized in modern genetics for the detection of genes and polymorphisms (mutations) within domesticated animal (mostly livestock) genomes that are related to traits of economic importance to humans. Examples are given of how genetic analysis allows to determine key genes associated with the quality and quantity of milk in cattle and key genes for meat production. Various questions are reviewed, such as how contemporary methods of genome sequencing allow to maximise the effective detection of coding and regulatory DNA polymorphisms within the genomes of major domesticated mammals (cattle, sheep and pigs) and the history of their formation from the standpoint of genetics

The ground state in a spin-one color superconductor

Color superconductors in which quarks of the same flavor form Cooper pairs are investigated. These Cooper pairs carry total spin one. A systematic group-theoretical classification of possible phases in a spin-one color superconductor is presented, revealing parallels and differences to the theory of superfluid $^3$He. General expressions for the gap parameter, the critical temperature, and the pressure are derived and evaluated for several spin-one phases, with special emphasis on the angular structure of the gap equation. It is shown that the (transverse) color-spin-locked phase is expected to be the ground state.Comment: 36 pages, 3 figures, error corrected in App. C, conclusion change

The Trapped Polarized Fermi Gas at Unitarity

We consider population-imbalanced two-component Fermi gases under external harmonic confinement interacting through short-range two-body potentials with diverging s-wave scattering length. Using the fixed-node diffusion Monte Carlo method, the energies of the "normal state" are determined as functions of the population-imbalance and the number of particles. The energies of the trapped system follow, to a good approximation, a universal curve even for fairly small systems. A simple parameterization of the universal curve is presented and related to the equation of state of the bulk system.Comment: 4 pages, 2 tables, 2 figure

Pairing of a trapped resonantly-interacting fermion mixture with unequal spin populations

We consider the phase separation of a trapped atomic mixture of fermions with unequal spin populations near a Feshbach resonance. In particular, we determine the density profile of the two spin states and compare with the recent experiments of Partridge et al. (cond-mat/0511752). Overall we find quite good agreement. We identify the remaining discrepancies and pose them as open problems.Comment: 4 figures, 4+ pages, revtex

Students Today Into Entrepreneurs Tomorrow: The Impact of Major Choice on Grit and Risk Aversion

The Bureau of Labor Statistics reports that more than half of all start-ups in the US fail before their fifth year in operation (BLS, 2010). As a result, since the mid-1980s, colleges and universities nationwide have continued to increase opportunities and funding to improve entrepreneurial education. Yet, little is known about how the choices students make during their time in college, like major choice, impact personality traits that are beneficial to entrepreneurship. Specifically, these traits are grit and risk aversion. The theoretically successful entrepreneurs are able to be committed to goals and remain motivated despite setbacks. Simultaneously they must maintain comfort in a culture of uncertainty associated with self-employment. This study employs data from a survey taken by 504 of the 1650 Ursinus College students, in varying disciplines, to understand that major choice is able to positively impact a student’s level of grit while it does not impact risk aversio

Evaluation of Traditional Security Solutions in the SCADA Environment

Supervisory Control and Data Acquisition (SCADA) systems control and monitor the electric power grid, water treatment facilities, oil and gas pipelines, railways, and other Critical Infrastructure (CI). In recent years, organizations that own and operate these systems have increasingly interconnected them with their enterprise network to take advantage of cost savings and operational benefits. This trend, however, has introduced myriad vulnerabilities associated with the networking environment. As a result, the once isolated systems are now susceptible to a wide range of threats that previously did not exist. To help address the associated risks, security professionals seek to incorporate mitigation solutions designed for traditional networking and Information Technology (IT) systems. Unfortunately, the operating parameters and security principles associated with traditional IT systems do not readily translate to the SCADA environment. Security solutions for IT systems focus primarily on protecting the confidentiality of system and user data. Alternatively, SCADA systems must adhere to strict safety and reliability requirements and rely extensively on system availability. Mitigation strategies designed for traditional IT systems must first be evaluated prior to deployment on a SCADA system or risk adverse operational impacts such as a catastrophic oil spill, poisoning a water supply, or the shutdown of an electrical grid. This research evaluates the suitability of deploying a Host-Based Intrusion Detection System (IDS) to the Department of Defense SCADA fuels system. The impacts of the Host Intrusion Prevention System (HIPS) installed on the SCADA network\u27s Human Machine Interface (HMI) is evaluated. Testing revealed that the HIPS agent interferes with the HMI\u27s system services during startup. Once corrected, the HMI and connected SCADA network inherit the protections of the HIPS security agent and defenses associated with the Host-Based Security System

Divergent Criticality – A Mechanism of Neural Function for Perception and Learning

The natural world presents opportunities to all organisms as they compete for the biological-value afforded to them through their ecological engagement. This presents two fundamental requirements for perceiving such opportunities: to be able to recognise value and learning how to access new value. Though many theoretical accounts of how we might achieve such selectionist ends have been explored – how ‘perception’ and ‘learning’ resonate with life’s challenges and opportunities, to date, no explanation has yet been able to naturalise such perception adequately in the Universal laws that govern our existence – not only for explaining the human experience of the world, but in exploring the true nature of our perception. This thesis explores our perceptions of engaging with the world and seeks to explain how the demands of our experiences resonate with the efficient functioning of our brain. It proposes, that in a world of challenge and opportunity, rather than the efficient functioning of our neural resources, it is, instead, the optimising of ‘learning’ that is selected for, as an evolutionary priority. Building on existing literature in the fields of Phenomenology, Free Energy and Neuroscience, this thesis considers perception and learning as synonymous with the cognitive constructs of an ‘attention’ tuned for learning optimisation, and explores the processes of learning in neural function. It addresses the philosophical issues of how an individual’s perception of subjective experiences, might provide some empirical objectivity in proposing a ‘Tolerance’ hypothesis. This is a relative definition able to coordinate a ‘perception of experience’ in terms of an learning-function, grounded in free-energy theory (the laws of physics) and the ecological dynamics of a spontaneous or ‘self- organising’ mechanism – Divergent Criticality. The methodology incorporated three studies: Pilot, Developmental and Exploratory. Over the three studies, Divergent Criticality was tested by developing a functional Affordance measure to address the Research Question – are perceptions as affective-cognitions made aware as reflecting the agential mediation of a self-regulating, optimal learning mechanism? Perception questionnaires of Situational Interest and Self-concept were used in Study One and Study Two to investigate their suitability in addressing the Research Question. Here, Factor Analysis and Structural Equation Modelling assessed the validity and reliability of these measures, developing robust questionnaires and a research design for testing Divergent Criticality. In Study Three, the Divergent Criticality hypothesis was found to be significant, supporting that a Divergent Criticality mechanism is in operation: When individuals are engaging with dynamic ecological challenges, perception is affective in accordance with Tolerance Optimisation, demonstrating that a Divergent Criticality mechanism is driving individuals to the limits of their Effectivity – an optimal learning state which is fundamental to life and naturalised in Universal laws

A constrained random-force model for weakly bending semiflexible polymers

The random-force (Larkin) model of a directed elastic string subject to quenched random forces in the transverse directions has been a paradigm in the statistical physics of disordered systems. In this brief note, we investigate a modified version of the above model where the total transverse force along the polymer contour and the related total torque, in each realization of disorder, vanish. We discuss the merits of adding these constraints and show that they leave the qualitative behavior in the strong stretching regime unchanged, but they reduce the effects of the random force by significant numerical prefactors. We also show that a transverse random force effectively makes the filament softer to compression by inducing undulations. We calculate the related linear compression coefficient in both the usual and the constrained random force model.Comment: 4 pages, 1 figure, accepted for publication in PR