105 research outputs found

    Microbiological and epizootological characterization of materials from wastewater treatment plant

    Get PDF
    Studies were carried out for the presence of microorganisms of major groups, containing pathogenic agents with epizootological importance, in order characteristic of their dynamics at different levels in the treatment plant and assessing the environmental safety of the final materials. For this purpose were traced the changes in the quantities of microorganisms contained in the materials from successive levels of processing. It was found that the purified water inlet and outlet does not contain Salmonella enterica. Presence of Escherichia coli and Clostridium perfringens beyond the requirements of the regulation (Decree N339, 2004) was not established, as well as Enterococcus spp. The tested sludge contained microorganisms from these groups and could not be deposited in the soil without prior aerobic or anaerobic processing. The draining in the nature of treated water at the outlet of plant does not hide environmental risk. In addition to monitoring of the sanitary indicative bacteria, the following of the main groups of Gram-negative and Gram-positive microorganisms in the water and sewage sludge allows more reliable assessment of their decontamination. Furthermore, the new approach for reporting the results in a unit of dry matter of the studied materials, proposed here, allows their more exact comparison

    Reduction of sanitary indicator microorganisms in anaerobic digestion of poultry litter in combination with silages

    Get PDF
    ABSTRACT: In connection with experiments aimed at optimizing anaerobic digestion of organic fertilizers, microbiological tests were performed to assess the epizootiological safety of resulting finished product to fertilize the soil by quantities of sanitary indicator microorganisms. Mixtures of substrates were composed and tested in technological parameters established for other experiments: mesophilic temperature regime 33oC, dry matter content of 7%, residence time in the digester 15 days. The substrates tested were beetroot, sugar and salad beets, corn silage and leaves of Paulownia elongata, and silage combinations of these feeds in ratio 60:40 with mulch litter from broiler chickens. It was found that significant reduction of microorganisms was realized in the final products, which were assessed as safe for soil application. The ensiling of poultry litter in combinations of these feeds had the effect of reducing the amount of microorganisms in almost all examined groups therein. The most significant was the reduction in the quantity of sanitary revealing bacteria in the manure after its ensilage with autumn leaves of P. elongata and beetroot, and the least - with the participation of sugar beet. Microbial reduction was to the greatest extent in bioslime produced by anaerobic digestion of poultry litter ensiled with corn. Of the silages from different types of beets with poultry manure, during anaerobic digestion highest decontamination was achieved in this with sugar beets. After anaerobic degradation of the studied feed without poultry litter, at least microorganisms were found in bioslimes from the three types of beet, as well from the silage from P. elongata. РЕЗЮМЕ: Във връзка с експерименти, насочени към оптимизиране на анаеробното разграждане на органични торове, са извършени микробиологични изследвания за преценка на епизоотологичната безопасност на получените крайни продукти за наторяване на почви според количествата на санитарно индикаторните микроорганизми. Съставени са смеси от субстрати при установени при други експерименти технологични параметри: мезофилен температурен режим 33оС, съдържание на сухо вещество 7%, време на престой в биореактора 15 денонощия. Изпитани са захарно, кръмно и салатно цвекло, царевичен силаж и листа от Paulownia elongata, както и силажи от комбинации на тези фуражи в съотношение 60:40 с торова постеля от пилета-бройлери. Установено е, че се осъществява значително редуциране на микроорганизмите в крайните продукти, които се преценяват като безопасни за внасяне в почвите. В най-голяма степен микробната редукция е при биошлама, получен при анаеробното разграждане на комбинацията от торова постеля с царевичен силаж. От трите вида цвекло, силажирани с птичи тор, при анаеробно разграждане се постига най-висока деконтаминация с участие на захарното цвекло. При анаеробно разграждане на изследваните фуражи без птичи тор най-малко микроорганизми се установяват в биошламовете от трите вида цвекло, както и в силажа от P. elongata

    Tunable single- and dual-wavelength SHG from diode-pumped PPKTP waveguides

    Get PDF
    A compact, all-room-temperature, widely tunable, continuous wave laser source in the green spectral region (502.1–544.2 nm) with a maximum output power of 14.7 mW is demonstrated. This was made possible by utilizing second-harmonic generation (SHG) in a periodically poled potassium titanyl phosphate (PPKTP) crystal waveguide pumped by a quantum-well external-cavity fiber-coupled diode laser and exploiting the multimode-matching approach in nonlinear crystal waveguides. The dual-wavelength SHG in the wavelength region between 505.4 and 537.7 nm (with a wavelength difference ranging from 1.8 to 32.3 nm) and sum-frequency generation in a PPKTP waveguide is also demonstrated

    Broadband amplitude squeezing in a periodically poled KTiOPO_4 waveguide

    Full text link
    We generated -2.2 dB of broadband amplitude squeezing at 1064 nm in a periodically poled KTiOPO_4 (PPKTP) waveguide, by coupling of the fundamental and second harmonic continuous-wave fields. This is the largest amount of squeezing obtained to date in a KTP waveguide, limited by propagation losses. This result paves the way for further improvements by use of lower-loss buried ion-exchanged waveguides.Comment: 3 pages, 2 figures, submitted for publicatio

    Microbiological evaluation of sewage sludge in terms of possibility of applications in soil as a fertilizer

    Get PDF
    The studies were carried out of sewage sludge from wastewater treatment plant for the presence of microorganisms of several main groups, containing pathogenic representatives with epizootological significance (Gram-negative aerobic bacteria, E. coli, Clostridium perfringens, the genera Pseudomonas, Staphylococcus, Enterococcus, fungi, and the total number of microorganisms), in order to assess the environmental safety of the final product. In parallel similar studies were made of fresh and composted cattle manures. A comparison of the results was made with the ready for manuring compost in order to assess the possibilities for the use of sludge for fertilizing. The quantities of microorganisms were given in CFU per 1 g of the investigated material, as well as per 1 g of dry substance for each of them. In our opinion this new approach to the reporting of the results per unit of dry matter of the investigated materials, allows for a more accurate comparison. It was found that the examined sewage sludge from wastewater treatment plant were rich in microorganisms from studied groups and their direct application in soils without prior treatment by aerobic or anaerobic digestion may represent epidemiological danger

    New generalized fuzzy metrics and fixed point theorem in fuzzy metric space

    Get PDF
    In this paper, in fuzzy metric spaces (in the sense of Kramosil and Michalek (Kibernetika 11:336-344, 1957)) we introduce the concept of a generalized fuzzy metric which is the extension of a fuzzy metric. First, inspired by the ideas of Grabiec (Fuzzy Sets Syst. 125:385-389, 1989), we define a new G-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by M Grabiec). Next, inspired by the ideas of Gregori and Sapena (Fuzzy Sets Syst. 125:245-252, 2002), we define a new GV-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by V Gregori and A Sapena). Moreover, we provide the condition guaranteeing the existence of a fixed point for these single-valued contractions. Next, we show that the generalized pseudodistance J:X×X→[0,∞) (introduced by Włodarczyk and Plebaniak (Appl. Math. Lett. 24:325-328, 2011)) may generate some generalized fuzzy metric NJ on X. The paper includes also the comparison of our results with those existing in the literature

    Preliminary data on COVID-19 in patients with hemoglobinopathies : A multicentre ICET-A study

    Get PDF
    Objectives: This study aims to investigate, retrospectively, the epidemiological and clinical characteristics, laboratory results, radiologic findings, and outcomes of COVID-19 in patients with transfusion-dependent β thalassemia major (TM), β-thalassemia intermedia (TI) and sickle cell disease (SCD). Design: A total of 17 Centers, from 10 countries, following 9,499 patients with hemoglobinopathies, participated in the survey. Main outcome data: Clinical, laboratory, and radiologic findings and outcomes of patients with COVID-19 were collected from medical records and summarized. Results: A total of 13 patients, 7 with TM, 3 with TI, and 3 with SCD, with confirmed COVID-19, were identified in 6 Centers from different countries. The overall mean age of patients was 33.7±12.3 years (range:13-66); 9/13 (69.2%) patients were females. Six patients had pneumonia, and 4 needed oxygen therapy. Increased C-reactive protein (6/10), high serum lactate dehydrogenase (LDH; 6/10), and erythrocyte sedimentation rate (ESR; 6/10) were the most common laboratory findings. 6/10 patients had an exacerbation of anemia (2 with SCD). In the majority of patients, the course of COVID-19 was moderate (6/10) and severe in 3/10 patients. A 30-year-old female with TM, developed a critical SARS-CoV-2 infection, followed by death in an Intensive Care Unit. In one Center (Oman), the majority of suspected cases were observed in patients with SCD between the age of 21 and 40 years. A rapid clinical improvement of tachypnea/dyspnea and oxygen saturation was observed, after red blood cell exchange transfusion, in a young girl with SCD and worsening of anemia (Hb level from 9.2 g/dl to 6.1g/dl). Conclusions: The data presented in this survey permit an early assessment of the clinical characteristics of COVID 19 in different countries. 70% of symptomatic patients with COVID-19 required hospitalization. The presence of associated co-morbidities can aggravate the severity of COVID- 19, leading to a poorer prognosis irrespective of age

    Robust regression for periodicity detection in non-uniformly sampled time-course gene expression data

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In practice many biological time series measurements, including gene microarrays, are conducted at time points that seem to be interesting in the biologist's opinion and not necessarily at fixed time intervals. In many circumstances we are interested in finding targets that are expressed periodically. To tackle the problems of uneven sampling and unknown type of noise in periodicity detection, we propose to use robust regression.</p> <p>Methods</p> <p>The aim of this paper is to develop a general framework for robust periodicity detection and review and rank different approaches by means of simulations. We also show the results for some real measurement data.</p> <p>Results</p> <p>The simulation results clearly show that when the sampling of time series gets more and more uneven, the methods that assume even sampling become unusable. We find that M-estimation provides a good compromise between robustness and computational efficiency.</p> <p>Conclusion</p> <p>Since uneven sampling occurs often in biological measurements, the robust methods developed in this paper are expected to have many uses. The regression based formulation of the periodicity detection problem easily adapts to non-uniform sampling. Using robust regression helps to reject inconsistently behaving data points.</p> <p>Availability</p> <p>The implementations are currently available for Matlab and will be made available for the users of R as well. More information can be found in the web-supplement <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p
    corecore