815 research outputs found

    Redox-based electrochemical adsorption technologies for energy-efficient water purification and wastewater treatment

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    Water scarcity, both economic and physical, affects close to a third of the world population. Efficient, affordable and robust purification technologies are needed for a range of separation contexts, from point-of-source treatment or remote in-situ purification devices to large-scale, centralized wastewater treatment facilities. Micropollutants (e.g., organic endocrine disruptors, pesticides, household chemicals, dyes and heavy metal cations) pose a particularly vexing problem in wastewater treatment, since current technologies suffer from high energetic penalties and performance limitations when confronted with pollutants at these very low concentrations (nM to μM), often in the presence of excess competing species. Redox-based electrochemical technologies offer a next-generation purification technology. Through specifically designed chemical selectivity at the electrode interface, redox-based systems can achieve high separation factors towards toxic pollutants, at low overpotentials and much higher current efficiencies than needed for capacitive-based methods. We present a novel redox-mediated electrochemical system, utilizing organometallic polymeric electrodes, to target pollutants ranging from pesticides to toxic heavy metals. Capture and release are controlled solely by electrochemical potential, thus there is no need for chemical regenerants or post-treatment, with little chemical waste produced and low water usage ratios (\u3c0.05). In addition, an asymmetric configuration can be implemented to achieve higher electrochemical performance and energy storage; at the same time, we control the water chemistry (i.e., no current diversion to water reduction and pH changes) and thus enhance separation factors \u3e300 towards target pesticides and organic pollutants in the μM range. Finally, through materials optimization, we show the strong stability of these electrodes for \u3e500 cycles with over 95% current efficiency. Please click Additional Files below to see the full abstract

    A mobile visual diary for personal pain management

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    Back-pain is one of the most prolific health problems within the population and costs industry lost revenue due to the amount of days people have to take off in order to recover. In this paper, we have targeted this problem and suggested a mobile app for visually diarizing the pain experience of patients. The Android platform is utilized and its technology stack forms the basis for this 3D centric application. Positive evaluations obtained provide evidence of the promising nature of the approach and indicate several future directions of research within mobile pain management

    Business in Engineering Education: Issues, Identities, Hybrids, and Limits

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    This chapter explores how engineering students are broadened in their education through the teaching of non-engineering subjects, such as business subjects, in order to develop critical thinking skills and self-knowledge of what it means to be an engineer. The goal of the chapter is to provide a commentary on the level of interaction, from design of courses to design of curricula, between business faculty and engineering faculty, and the results of that interaction. This chapter sets out to (i) explore whether there appears to be a place in engineering education curricula for reflective critique of assumptions related to business thinking, and why; (ii) discover what kinds of business issues are reflected in engineering education curricula, and for what purpose; (iii) explore the degree of business hybridization in engineering degree programs; (iv) ask who teaches business issues within engineering education? To this end a taxonomy of engineering enlightenment is proposed, and this is used to discuss evidence of broadening with engineering curricula. The approach adopted is to describe all relevant engineering degree programs in Ireland, based on their publicly available program information; examine the accreditation reports for these same programs; and then survey deans from colleges or schools of business to examine whether the business college/school is involved in the education of engineering students in the institution or university. If yes, how the business college or relevant business faculty are engaged in the design of engineering curricula. In order to enable a comparative discussion, the chapter will focus on Irish engineering programs that seek accreditation from Engineers Ireland for professional engineering. A number of hybrid engineering programs of study are also explored, and their apparent strengths discussed, including hybridity limits

    Rainbow domination and related problems on some classes of perfect graphs

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    Let kNk \in \mathbb{N} and let GG be a graph. A function f:V(G)2[k]f: V(G) \rightarrow 2^{[k]} is a rainbow function if, for every vertex xx with f(x)=f(x)=\emptyset, f(N(x))=[k]f(N(x)) =[k]. The rainbow domination number γkr(G)\gamma_{kr}(G) is the minimum of xV(G)f(x)\sum_{x \in V(G)} |f(x)| over all rainbow functions. We investigate the rainbow domination problem for some classes of perfect graphs

    Flavor in Minimal Conformal Technicolor

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    We construct a complete, realistic, and natural UV completion of minimal conformal technicolor that explains the origin of quark and lepton masses and mixing angles. As in "bosonic technicolor", we embed conformal technicolor in a supersymmetric theory, with supersymmetry broken at a high scale. The exchange of heavy scalar doublets generates higher-dimension interactions between technifermions and quarks and leptons that give rise to quark and lepton masses at the TeV scale. Obtaining a sufficiently large top quark mass requires strong dynamics at the supersymmetry breaking scale in both the top and technicolor sectors. This is natural if the theory above the supersymmetry breaking also has strong conformal dynamics. We present two models in which the strong top dynamics is realized in different ways. In both models, constraints from flavor-changing effects can be easily satisfied. The effective theory below the supersymmetry breaking scale is minimal conformal technicolor with an additional light technicolor gaugino. We argue that this light gaugino is a general consequence of conformal technicolor embedded into a supersymmetric theory. If the gaugino has mass below the TeV scale it will give rise to an additional pseudo Nambu-Goldstone boson that is observable at the LHC.Comment: 37 pages; references adde

    The Schroedinger Problem, Levy Processes Noise in Relativistic Quantum Mechanics

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    The main purpose of the paper is an essentially probabilistic analysis of relativistic quantum mechanics. It is based on the assumption that whenever probability distributions arise, there exists a stochastic process that is either responsible for temporal evolution of a given measure or preserves the measure in the stationary case. Our departure point is the so-called Schr\"{o}dinger problem of probabilistic evolution, which provides for a unique Markov stochastic interpolation between any given pair of boundary probability densities for a process covering a fixed, finite duration of time, provided we have decided a priori what kind of primordial dynamical semigroup transition mechanism is involved. In the nonrelativistic theory, including quantum mechanics, Feyman-Kac-like kernels are the building blocks for suitable transition probability densities of the process. In the standard "free" case (Feynman-Kac potential equal to zero) the familiar Wiener noise is recovered. In the framework of the Schr\"{o}dinger problem, the "free noise" can also be extended to any infinitely divisible probability law, as covered by the L\'{e}vy-Khintchine formula. Since the relativistic Hamiltonians |\nabla | and +m2m\sqrt {-\triangle +m^2}-m are known to generate such laws, we focus on them for the analysis of probabilistic phenomena, which are shown to be associated with the relativistic wave (D'Alembert) and matter-wave (Klein-Gordon) equations, respectively. We show that such stochastic processes exist and are spatial jump processes. In general, in the presence of external potentials, they do not share the Markov property, except for stationary situations. A concrete example of the pseudodifferential Cauchy-Schr\"{o}dinger evolution is analyzed in detail. The relativistic covariance of related waveComment: Latex fil
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