113 research outputs found

    The Aerobic Biodegradation Kinetics of Plant Tannins in Industrial Wastewater

    Get PDF
    This paper describes an experimental determination of the biodegradation rate for tannins present in industrial wastewater, after the extraction of chestnut chips. Experiments were performed in a laboratory aerobic reactor (Armfield) by using biomass from an existing industrial wastewater treatment plant. The outlet tannins concentration was determined under various processing conditions. Simultaneously, an optical microscope was used to monitor the mix of microbiological cultures in the biomass. On the basis of data obtained in experiments, non-linear regression was used to perform parametric analysis of various kinetic models, which took into account inhibition, as quoted in literature (Haldane, Edwards, Aiba, Luong). The statistical analysis, based on the P-criterion, F-criterion, adjusted coefficient of determination, Kolmogorov-Smirnov test and root mean squared error, showed that the biodegradation of plant tannins in industrial wastewater under selected conditions for aerobic digestion, can be most successfully described statistically by the Aiba\u27s kinetic model

    Similarity Measures For Incomplete Database Instances

    Get PDF
    The problem of comparing database instances with incompleteness is prevalent in applications such as analyzing how a dataset has evolved over time (e.g., data versioning), evaluating data cleaning solutions (e.g., compare an instance produced by a data repair algorithm against a gold standard), or comparing solutions generated by data exchange systems (e.g., universal vs core solutions). In this work, we propose a framework for computing similarity of instances with labeled nulls, even of those without primary keys. As a side-effect, the similarity score computation returns a mapping between the instances’ tuples, which explains the score. We demonstrate that computing the similarity of two incomplete instances is NP-hard in the instance size in general. To be able to compare instances of realistic size, we present an approximate PTIME algorithm for instance comparison. Experimental results demonstrate that the approximate algorithm is up to three orders of magnitude faster than an exact algorithm for the computation of the similarity score, while the difference between approximate and exact scores is always smaller than 1%

    Reflective, polarizing, and magnetically soft amorphous Fe/Si multilayer neutron optics with isotope-enriched 11B4C inducing atomically flat interfaces

    Full text link
    The utilization of polarized neutrons is of great importance in scientific disciplines spanning materials science, physics, biology, and chemistry. Polarization analysis offers insights into otherwise unattainable sample information such as magnetic domains and structures, protein crystallography, composition, orientation, ion-diffusion mechanisms, and relative location of molecules in multicomponent biological systems. State-of-the-art multilayer polarizing neutron optics have limitations, particularly low specular reflectivity and polarization at higher scattering vectors/angles, and the requirement of high external magnetic fields to saturate the polarizer magnetization. Here, we show that by incorporating 11B4C into Fe/Si multilayers, amorphization and smooth interfaces can be achieved, yielding higher neutron reflectivity, less diffuse scattering and higher polarization. Magnetic coercivity is eliminated, and magnetic saturation can be reached at low external fields (>2 mT). This approach offers prospects for significant improvement in polarizing neutron optics, enabling; nonintrusive positioning of the polarizer, enhanced flux, increased data accuracy, and further polarizing/analyzing methods at neutron scattering facilities

    The ACTIVE (Acute Cholecystitis Trial Invasive Versus Endoscopic) study: Multicenter randomized, double-blind, controlled trial of laparoscopic (LC) versus open (LTC) surgery for acute cholecystitis (AC) in adults

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In some randomized trials successful laparoscopic cholecystectomy for cholecystitis is associated with an earlier recovery and shorter hospital stay when compared with open cholecystectomy. Other studies did not confirm these results and showed that the potential advantages of laparoscopic cholecystectomy for cholecystitis can be offset by a high conversion rate to open surgery. Moreover in these studies a similar postoperative programme to optimize recovery comparing laparoscopic and open approaches was not standardized. These studies also do not report all eligible patients and are not double blinded.</p> <p>Design</p> <p>The present study project is a prospective, randomized investigation. The study will be performed in the Department of General, Emergency and Transplant Surgery St Orsola-Malpighi University Hospital (Bologna, Italy), a large teaching institutions, with the participation of all surgeons who accept to be involved in (and together with other selected centers). The patients will be divided in two groups: in the first group the patient will be submitted to laparoscopic cholecystectomy within 72 hours after the diagnosis while in the second group will be submitted to laparotomic cholecystectomy within 72 hours after the diagnosis.</p> <p>Trial Registration</p> <p>TRIAL REGISTRATION NUMBER ISRCTN27929536 – The ACTIVE (Acute Cholecystitis Trial Invasive Versus Endoscopic) study. A multicentre randomised, double-blind, controlled trial of laparoscopic versus open surgery for acute cholecystitis in adults.</p
    corecore