1,129 research outputs found

    REDUCTION OF FAECAL MICROBIOLOGICAL INDICATORS IN DIFFERENT COMPOST TOILETS

    Get PDF
    Large variations in numbers of faecal indicator bacteria were found irrespective of the storage time of collected human faeces. Little heat seemed generated from composting processes when bin units were stored locally in households. The low reduction in microbiological parameters and very limited temperature increase were generally corroborated by the results obtained in experiment 2 when pathogen indicators were added to thoroughly mixed faecal matter. Even though Salmonella died of rapidly the other faecal bacterial indicators survived in large numbers. We conclude, that the collection and storage of human faeces in the closed plastic bins studied here is associated with only little temperature increase and subsequent reduction in faecal bacterial indicators and pathogens. Thus, the bin units do not seem especially suitable for composting and hygienisation of human faece

    OVERLEVELSE AF INDIKATORORGANISMER OG SMITSTOFFER I KOMPOSTTOILETTER OG VED SIMULERET CENTRALISERET EFTERKOMPOSTERING AF AFFØRING FRA MENNESKER

    Get PDF
    Som resultat af projekterne kan drages følgende hovedkonklusioner om kompostering af fæces fra mennesker: Fæces fra de undersøgte typer af kompostbeholdere bør ikke anvendes til jordbrugsformål uden viderebehandling, da dette skønnes at være behæftet med hygiejne- og sundhedsrisici. Det skyldes, at der ikke blev dokumenteret egentlige termofile temperaturstigninger i fæcesmaterialet i komposttoiletenhederne i Hjortshøj, Dyssekilde og Sverige, og at fækale indikatorbakteriers antal varierede voldsomt, og der ingen entydig tendens var til forekomst af lavere kimtal ved lange opbevaringstider af de opsamlede fækalier

    Estimation of Migration Flows: A Validation of Entropy Solutions

    Get PDF
    The collection of disaggregated data is in most economic areas an expensive as well as a time-consuming procedure. If real data could be replaced by estimations from data on a highly aggregated level, much effort could be saved. The entropy maximizing method can be used to estimate interregional migration flow matrices for the whole population or subgroups of the population, when the available data are in an aggregated form. This means estimating the elements of matrices in which individuals a reclassified according to two or more discrete variables. Matrices of this form are called contingency tables. In this paper we present the entropy-maximizing method and test its validity for different levels of data aggregation. The tests are carried out by means of information theory and the chi-square distribution. For the tests we have used data from two of the countries that produce disaggregated data, Sweden and Austria

    Current driven electrostatic and electromagnetic ion cyclotron instabilities

    Get PDF
    Growth rates and parameter dependences are calculated for the current driven instabilities of electrostatic (with finite-beta corrections) and electromagnetic ion cyclotron waves. For 0.25 (T sub e)/(T sub i) 2.5, ion cyclotron waves have large growth rates, while ion acoustic waves are still stable. In fusion devices, where electrostatic waves may be stable, electromagnetic ion cyclotron waves are unstable for beta sub i 0.001

    Influence of the Lower Hybrid Drift Instability on the onset of Magnetic Reconnection

    Full text link
    Two-dimensional and three-dimensional kinetic simulation results reveal the importance of the Lower-Hybrid Drift Instability LHDI to the onset of magnetic reconnection. Both explicit and implicit kinetic simulations show that the LHDI heats electrons anisotropically and increases the peak current density. Linear theory predicts these modifications can increase the growth rate of the tearing instability by almost two orders of magnitude and shift the fastest growing modes to significantly shorter wavelengths. These predictions are confirmed by nonlinear kinetic simulations in which the growth and coalescence of small scale magnetic islands leads to a rapid onset of large scale reconnection

    Removal of Escherichia coli in treated wastewater used for food production in Morogoro, Tanzania

    Get PDF
    Acadmic Journal Vol. 10(33), pp. 1344-1350The aim of this study was to assess the removal efficiency of Escherichia coli at Mafisa and Mzumbe domestic wastewater treatment ponds in Morogoro, Tanzania. The study was done from October, 2013 to April, 2014. A total of 125 water samples from inlets and subsequent anaerobic, facultative and maturation ponds as well as treated wastewater were collected and analysed for E. coli. The estimated retention times of the wastewater treatment units were 19 and 22 days in Mafisa and Mzumbe ponds, respectively. The concentration of E. coli ranged from 4.70 to 5.60 log cfu/mL in untreated wastewater and was reduced to <1.00 to 2.00 log cfu/mL in the treated wastewater. During rainy and cold seasons, the effluent discharged out at Mafisa during August 2013; and March and April, 2014 was about 2 log cfu/mL while at Mzumbe E. coli concentration in effluent discharged out was up to 1.23 log cfu/mL. The concentration of E. coli in untreated and treated wastewater from the two wastewater treatment ponds study sites were comparable (P<0.05). Reduction of E. coli concentration in wastewater treatment ponds study sites was significant with less reduction seen at Mafisa, during rainy and cold seasons in March, April and August. To conclude, the simple wastewater treatment ponds in the study sites were effective and demonstrated potential for reduction of public health risks associated with use of treated wastewater in agricultural irrigation and aquaculture

    proGenomes: a resource for consistent functional and taxonomic annotations of prokaryotic genomes

    Get PDF
    The availability of microbial genomes has opened many new avenues of research within microbiology. This has been driven primarily by comparative genomics approaches, which rely on accurate and consistent characterization of genomic sequences. It is nevertheless difficult to obtain consistent taxonomic and integrated functional annotations for defined prokaryotic clades. Thus, we developed proGenomes, a resource that provides user-friendly access to currently 25 038 high-quality genomes whose sequences and consistent annotations can be retrieved individually or by taxonomic clade. These genomes are assigned to 5306 consistent and accurate taxonomic species clusters based on previously established methodology. proGenomes also contains functional information for almost 80 million protein-coding genes, including a comprehensive set of general annotations and more focused annotations for carbohydrate-active enzymes and antibiotic resistance genes. Additionally, broad habitat information is provided for many genomes. All genomes and associated information can be downloaded by user-selected clade or multiple habitat-specific sets of representative genomes. We expect that the availability of high-quality genomes with comprehensive functional annotations will promote advances in clinical microbial genomics, functional evolution and other subfields of microbiology. proGenomes is available at http://progenomes.embl.de
    corecore