This paper explores the potential methods for evaluating a healing system for asphalt pavements. The healing system under investigation involves compartmented calcium-alginate fibres encapsulating an asphalt binder healing agent (rejuvenator). This system presents a novel method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are used to distribute the rejuvenator throughout the pavement mixture, thereby overcoming some of the problems associated with alternate asphalt pavement healing methods, i.e., spherical capsules and hollow fibres. The asphalt healing efficiency methods to be evaluated in this paper include: (i) standard test methods for asphalt pavements, such as the Indirect Tensile Strength test and the 4 Point Bending Fatigue test; and (ii) alternative fracture tests such as the Semi Circular Bend test. The study employs fracture theory in order to evaluate the efficiency of the damage repair. The research findings demonstrate that including compartmented calcium-alginate fibres encapsulating a rejuvenator into an asphalt pavement mix does not significantly improve the healing properties of the asphalt pavement. Nevertheless, the findings indicate that, with further enhancement, compartmented calcium alginate fibres may present a promising new approach for the development of self-healing asphalt pavement systems. Additionally, the test results indicate that the 4 point bend fatigue test is the most suitable test for evaluating the performance of self healing asphalt pavements.
An LCL filter utilized in an active front end (AFE) converter can generate significant resonance, which can affect quality and stability of the system. Thus, a proper active or passive damping technique and/or a suitable controller is required to be designed for the converter. The duty cycle constraint—though inevitable in practical inverter systems—is often ignored in most of the existing literature. The effects of measurement noise on filter control system performance must be considered and evaluated under different conditions. Finally, almost all inverter control systems are implemented digitally using microcontrollers. Consequently, the effects of sampling on control system stability and performance should be evaluated as well. Thus, this paper presents stability analysis of an AFE converter-based filter design with a complete practical system configuration, including saturation and sampling blocks and measurement noises. Mathematical analysis and simulations have been carried out to validate the proposed method.
Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both in charged- and in neutral-current processes, we analyse the ingredients necessary to provide a combined description of these phenomena. By means of an Effective Field Theory (EFT) approach, based on the hypothesis of New Physics coupled predominantly to the third generation of left-handed quarks and leptons, we show how this is possible. We demonstrate, in particular, how to solve the problems posed by electroweak precision tests and direct searches with a rather natural choice of model parameters, within the context of a U(2)q ×U(2)ℓ flavour symmetry. We further exemplify the general EFT findings by means of simplified models with explicit mediators in the TeV range: coloured scalar or vector leptoquarks and colour-less vectors. Among these, the case of an SU(2)L-singlet vector leptoquark emerges as a particularly simple and successful framework.
We introduce two light scalar leptoquarks to accomodate the recent hints of lepton universality violation in $B$ meson decays. Scalar leptoquark $S_3 (\overline{3},3,1/3)$ with left-handed couplings to 2nd and 3rd generations of charged leptons and down-type quarks addresses both $R_{K^{(*)}}$ and $R_{D^{(*)}}$. The second state, $\tilde R_2(3,2,1/6)$, ensures compatibility with additional flavor constraints and secures unification of gauge couplings in the context of an $SU(5)$ GUT model without any conflict with the stringent limits from observed proton stability. We present the global fit of the flavor couplings and identify $B \to K \bar\nu\nu$ as the most sensitive channel to probe this model. Large couplings to $\tau$ leptons are confronted with the experimental searches for $\tau$ final states at the Large Hadron Collider. These searches comprise a study of decay products of the leptoquark pair production, as well as, and more importantly, an analysis of the high-mass $\tau\tau$ final states.
Improving the interface between copper and carbon nanotubes (CNTs) offers a straightforward strategy for the effective manufacturing and utilisation of Cu-CNT composite material that could be used in various industries including microelectronics, aerospace and transportation. Motivated by a combination of structural and electrical measurements on Cu-M-CNT bimetal systems (M = Ni, Cr) we show, using first principles calculations, that the conductance of this composite can exceed that of a pure Cu-CNT system and that the current density can even reach 1011 A cm-2. The results show that the proper choice of alloying element (M) and type of contact facilitate the fabrication of ultra-conductive Cu-M-CNT systems by creating a favourable interface geometry, increasing the interface electronic density of states and reducing the contact resistance. In particular, a small concentration of Ni between the Cu matrix and the CNT using either an "end contact" and or a "dot contact" can significantly improve the electrical performance of the composite. Furthermore the predicted conductance of Ni-doped Cu-CNT "carpets" exceeds that of an undoped system by ∼200%. Cr is shown to improve CNT integration and composite conductance over a wide temperature range while Al, at low voltages, can enhance the conductance beyond that of Cr.
Every long bone fracture in orthopedic surgery represents a possible scenario for devel- opment of embolism complication, especially the fat embolism. There is no scientific explanation why fat embolism occurs and what are the hypotheses for development of fat embolism or the proper way of prevention, but just speculations and possible theories in the evolution of the clinical picture of fat embolism syndrome. Throughout this chap- ter, the authors will explain the possible theories of development of fat embolism, risk factors, pathology, and pathophysiology during progress of the clinical picture and signs of the fat embolism syndrome and therapy.
M1 and M2 activated macrophages (Mϕs) have different roles in inflammation. Because pathogens may first encounter resting cells, we investigated lipid mediator profiles prior to full activation. Human monocytes were differentiated with granulocyte Mϕ colony‐stimulating factor (GM‐CSF) or Mϕ colony‐stimulating factor (M‐CSF), which are known to prime toward M1 or M2 phenotypes, respectively. Lipid mediators released during resting conditions and produced in response to bacterial stimuli (LPS/N‐formylmethionyl‐leucyl‐phenylalanine or peptidoglycan) were quantified by liquid chromatography‐mass spectrometry. In resting conditions, both Mϕ phenotypes released primarily proresolving lipid mediators (prostaglandin E2 metabolite, lipoxin A4, and 18‐hydroxyeicosapentaenoic acid). A striking shift toward proinflammatory eicosanoids was observed when the same cells were exposed (30 min) to bacterial stimuli: M‐CSF Mϕs produced considerably more 5‐lipoxygenase products, particularly leukotriene C4, potentially linked to M2 functions in asthma. Prostaglandins were formed by both Mϕ types. In the M‐CSF cells, there was also an enhanced release of arachidonic acid and activation of cytosolic phospholipase A2. However, GM‐CSF cells expressed higher levels of 5‐lipoxygenase and 5‐lipoxygenase–activating protein, and in ionophore incubations these cells also produced the highest levels of 5‐hydroxyeicosatetraenoic acid. In summary, GM‐CSF and M‐CSF Mϕs displayed similar proresolving lipid mediator formation in resting conditions but shifted toward different proinflammatory eicosanoids upon bacterial stimuli. This demonstrates that preference for specific eicosanoid pathways is primed by CSFs before full M1/M2 activation.—Lukic, A., Larssen, P., Fauland, A., Samuelsson, B., Wheelock, C.E., Gabrielsson, S., Radmark, O. GM‐CSF– and M‐CSF–primed macrophages present similar resolving but distinct inflammatory lipid mediator signatures. FASEB J. 31, 4370–4381 (2017). www.fasebj.org
This paper presents results of fractal analysis of fracture systems in upper Triassic dolomites in Žumberak Mountain, Croatia. Mechanical rock characteristics together with structural and diagenetic processes results with fracture systems that can be considered as fractals. They are scale-invariant in specific range of scales. Distribution of fractures can be than described with power law distribution and fractal dimension. Fractal dimension is a measure of how fractures fill the space. Fractal dimension can be estimated form photographs of outcrops by converting photographs to binary photographs. In binary photo there is only black (rock or fractures) and white (fractures or rock). Fractal dimension is then estimated based on box-counting method. In this paper we present results of fractal analysis from three outcrops. Results are very similar to previous published results from outcrops of dolomites in Slovenia. Obtained fractal dimensions are in range 2,69-2,78 and it depends on how fracture systems are distributed in the outcrop. Lower values indicate smaller number of fractures and higher significance of larger fractures. Higher values indicate distribution of more similar sized fractures throughout whole outcrop. Fractal dimension is very significant parameter in rock fracture system characterisation sense it describes how fractures are distributed in the outcrop. It can be used in discrete fracture network modelling if spatial distribution of fractures is represented with power law distribution.
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