929 research outputs found

    Thermodynamic curvature measures interactions

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    Thermodynamic fluctuation theory originated with Einstein who inverted the relation S=kBlnΩS=k_B\ln\Omega to express the number of states in terms of entropy: Ω=exp(S/kB)\Omega= \exp(S/k_B). The theory's Gaussian approximation is discussed in most statistical mechanics texts. I review work showing how to go beyond the Gaussian approximation by adding covariance, conservation, and consistency. This generalization leads to a fundamentally new object: the thermodynamic Riemannian curvature scalar RR, a thermodynamic invariant. I argue that R|R| is related to the correlation length and suggest that the sign of RR corresponds to whether the interparticle interactions are effectively attractive or repulsive.Comment: 29 pages, 7 figures (added reference 27

    Active Mass Under Pressure

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    After a historical introduction to Poisson's equation for Newtonian gravity, its analog for static gravitational fields in Einstein's theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein's theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century ago in the Hamburg Relativity Seminar and is resolved here.Comment: 28 pages, 4 figure

    Volunteer Income Tax Assistance Program: The Intersection of Business and Social Good

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    Over the past few years, Molloy College has produced a series of conference papers that illustrate what can be made possible when a disposition toward social responsibility becomes an academic program learning outcome. The belief that business can both damage the world, but also save the world, is at the foundation of why graduate students are required to demonstrate that the skills and knowledge gained can be applied to solve a real-world business problem. The twist is that the business problem must emerge from an organization that traditionally would not have available to it a team of consultants who can think creatively and proactively about the problem. These student consultants are charged to make actionable recommendations that potentially solve the organization’s business problem. This is a paper that couples a pedagogical philosophy with evidence of learning. This paper demonstrates that the students were able to draw from academic program learning to focus on the development of a solution-driven plan. The Molloy College mission establishes the founding belief in social responsibility, service, community, and study. The college’s commitment to academic excellence and the promotion of lifelong learning demonstrates the transformative education experienced by the students. This paper focuses on the consulting work performed for the not-for-profit organization, The Health and Welfare Council of Long Island

    Innovative observing strategy and orbit determination for Low Earth Orbit Space Debris

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    We present the results of a large scale simulation, reproducing the behavior of a data center for the build-up and maintenance of a complete catalog of space debris in the upper part of the low Earth orbits region (LEO). The purpose is to determine the performances of a network of advanced optical sensors, through the use of the newest orbit determination algorithms developed by the Department of Mathematics of Pisa (DM). Such a network has been proposed to ESA in the Space Situational Awareness (SSA) framework by Carlo Gavazzi Space SpA (CGS), Istituto Nazionale di Astrofisica (INAF), DM, and Istituto di Scienza e Tecnologie dell'Informazione (ISTI-CNR). The conclusion is that it is possible to use a network of optical sensors to build up a catalog containing more than 98% of the objects with perigee height between 1100 and 2000 km, which would be observable by a reference radar system selected as comparison. It is also possible to maintain such a catalog within the accuracy requirements motivated by collision avoidance, and to detect catastrophic fragmentation events. However, such results depend upon specific assumptions on the sensor and on the software technologies

    Zinc (II) and the single-stranded DNA binding protein of bacteriophage T4.

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    Complete Solving for Explicit Evaluation of Gauss Sums in the Index 2 Case

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    Let pp be a prime number, q=pfq=p^f for some positive integer ff, NN be a positive integer such that gcd(N,p)=1\gcd(N,p)=1, and let \k be a primitive multiplicative character of order NN over finite field \fq. This paper studies the problem of explicit evaluation of Gauss sums in "\textsl{index 2 case}" (i.e. f=\f{\p(N)}{2}=[\zn:\pp], where \p(\cd) is Euler function). Firstly, the classification of the Gauss sums in index 2 case is presented. Then, the explicit evaluation of Gauss sums G(\k^\la) (1\laN-1) in index 2 case with order NN being general even integer (i.e. N=2^{r}\cd N_0 where r,N0r,N_0 are positive integers and N03N_03 is odd.) is obtained. Thus, the problem of explicit evaluation of Gauss sums in index 2 case is completely solved

    Proposal of a population wide genome-based testing for Covid-19

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    Our lives (and deaths) have by now been dominated for two years by COVID-19, a pandemic that has caused hundreds of millions of disease cases, millions of deaths, trillions in economic costs, and major restrictions on our freedom. Here we suggest a novel tool for controlling the COVID-19 pandemic. The key element is a method for a population-scale PCR-based testing, applied on a systematic and repeated basis. For this we have developed a low cost, highly sensitive virus-genome-based test. Using Germany as an example, we demonstrate by using a mathematical model, how useful this strategy could have been in controlling the pandemic. We show using real-world examples how this might be implemented on a mass scale and discuss the feasibility of this approach
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