2,202 research outputs found

    Odor Removal Characteristics of a Laminated Film-Electrode Packed-Bed Nonthermal Plasma Reactor

    Get PDF
    Odor control has gained importance for ensuring a comfortable living environment. In this paper, the authors report the experimental results of a study on the detailed characteristics of a laminated film-electrode and a laminated film-electrode packed-bed nonthermal plasma reactor, which are types of dielectric barrier discharge (DBD) reactor used for odor control. These plasma reactors can be potentially used for the decomposition of volatile organic compounds (VOCs) and reduction of NOx. The reactor is driven by a low-cost 60-Hz neon transformer. Removal efficiencies under various experimental conditions are studied. The complete decomposition of the main odor component, namely, NH3, is achieved in a dry environment. The retention times are investigated for the complete removal of NH3 in the case of the film-electrode plasma reactor and the film-electrode packed-bed plasma reactor. The removal efficiency of the former reactor is lower than that of the latter reactor. Mixing another odor component such as CH3CHO in the gas stream has no significant effect on NH3 removal efficiency

    Dealing with multiple hazards and threats on cultural heritage sites: An assessment of 80 case studies

    Get PDF
    Purpose: Cultural heritage (CH) sites are not only important components of a country’s identity but can also be important drivers of tourism. However, an increasing number of extreme events associated with the impacts of climate change, natural hazards and human-induced threats are posing significant problems in conserving and managing cultural heritage worldwide. Consequently, improved climate change adaptation and enhanced hazard/threat mitigation strategies have become critical (but to-date under researched) considerations. This paper aims to identify the key hazards and threats to cultural heritage sites, the most common types of risks to CH and the strategies being adopted to mitigate or even eradicate those risks. Design/methodology: This paper reviews 80 CH case studies from around the world, which have been presented at a UNESCO International Training Course between 2006-2016. The case studies cover 45 different countries and provide practical insights into the key challenges being encountered in a variety of ‘at risk’ locations. Findings: The analysis assesses the key natural hazards and human-induced threats to the sites, an overview of the typical impacts to the tangible components of heritage and identifies the types of strategies being adopted to mitigate the risks, some of which could be transferred across cultural and geographical contexts. Originality: The paper provides a wealth of useful information related to how challenges faced by CH sites might be addressed in the futur

    Strange vector currents and the OZI-rule

    Get PDF
    We investigate the role of correlated πρ\pi\rho exchange in the extraction of matrix elements of the strange vector current in the proton. We show that a realistic isoscalar spectral function including this effect leads to sizeably reduced strange vector form factors based on the dispersion--theoretical analysis of the nucleons' electromagnetic form factors.Comment: 8 pp, plain LaTeX, uses epsf, 3 figure

    Extraction of the pion-nucleon sigma-term from the spectrum of exotic baryons

    Full text link
    The pion nucleon sigma-term is extracted on the basis of the soliton picture of the nucleon from the mass spectrum of usual and the recently observed exotic baryons, assuming that they have positive parity. The value found is consistent with that inferred by means of conventional methods from pion nucleon scattering data. The study can also be considered as a phenomenological consistency check of the soliton picture of baryons.Comment: 8 pages, 2 figures, references added, discussion extended, to appear in Eur.Phys.J.

    Unified Scaling Law for Earthquakes

    Full text link
    We show that the distribution of waiting times between earthquakes occurring in California obeys a simple unified scaling law valid from tens of seconds to tens of years, see Eq. (1) and Fig. 4. The short time clustering, commonly referred to as aftershocks, is nothing but the short time limit of the general hierarchical properties of earthquakes. There is no unique operational way of distinguishing between main shocks and aftershocks. In the unified law, the Gutenberg-Richter b-value, the exponent -1 of the Omori law for aftershocks, and the fractal dimension d_f of earthquakes appear as critical indices.Comment: 4 pages, 4 figure

    Machine Learning Assisted Characterization of Labyrinthine Pattern Transitions

    Full text link
    We present a comprehensive approach to characterizing labyrinthine structures that often emerge as a final steady state in pattern forming systems. We employ machine learning based pattern recognition techniques to identify the types and locations of topological defects of the local stripe ordering to augment conventional Fourier analysis. A pair distribution function analysis of the topological defects reveals subtle differences between labyrinthine structures which are beyond the conventional characterization methods. We utilize our approach to highlight a clear morphological transition between two zero-field labyrinthine structures in single crystal Bi substituted Yttrium Iron Garnet films. An energy landscape picture is proposed to understand the athermal dynamics that governs the observed morphological transition. Our work demonstrates that machine learning based recognition techniques enable novel studies of rich and complex labyrinthine type structures universal to many pattern formation systems

    Histiocyte-Rich Reactive Lymphoid Hyperplasia of the Liver: Unusual Morphologic Features

    Get PDF
    Reactive lymphoid hyperplasia (RLH) of the liver is a rare entity and has also been termed nodular lymphoid lesion or pseudolymphoma of the liver. We report a case of hepatic RLH exhibiting unusual histiocyte-rich histologic features in a 47-yr-old woman in conjunction with a renal cell carcinoma. A follow-up computed tomography scan was done 14 months after a right radical nephrectomy for renal cell carcinoma revealed a nodular lesion in segment 5 of the liver. The lesion was interpreted as metastatic renal cell carcinoma or hepatocellular carcinoma based on the history of the patient and radiologic findings. Wedge resection of segment 5 was done with sufficient distance from the mass. Microscopically, the lesion was composed predominantly of peculiar histiocytic proliferation and was characterized by lymphoid aggregates forming a lymphoid follicle with germinal centers. The present case and prior cases reported in the literature suggest that RLH of the liver appear to be a heterogenous group of reactive inflammatory lesions that are often associated with autoimmune disease or malignant tumors
    corecore