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End date: 2019 × Start date: 2016 × Start date: 1990 × DDC: 630 ×

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Now showing 1 - 10 of 117
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    Biogas crops grown in energy crop rotations: Linking chemical composition and methane production characteristics
    (Amsterdam : Elsevier, 2016) Herrmann, Christiane; Idler, Christine; Heiermann, Monika
    Methane production characteristics and chemical composition of 405 silages from 43 different crop species were examined using uniform laboratory methods, with the aim to characterise a wide range of crop feedstocks from energy crop rotations and to identify main parameters that influence biomass quality for biogas production. Methane formation was analysed from chopped and over 90 days ensiled crop biomass in batch anaerobic digestion tests without further pre-treatment. Lignin content of crop biomass was found to be the most significant explanatory variable for specific methane yields while the methane content and methane production rates were mainly affected by the content of nitrogen-free extracts and neutral detergent fibre, respectively. The accumulation of butyric acid and alcohols during the ensiling process had significant impact on specific methane yields and methane contents of crop silages. It is proposed that products of silage fermentation should be considered when evaluating crop silages for biogas production.
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    Hydrothermal carbonization (HTC): Near infrared spectroscopy and partial least-squares regression for determination of selective components in HTC solid and liquid products derived from maize silage
    (Amsterdam : Elsevier, 2014) Reza, M. Toufiq; Becker, Wolfgang; Sachsenheimer, Kerstin; Mumme, Jan
    Near-infrared (NIR) spectroscopy was evaluated as a rapid method of predicting fiber components (hemicellulose, cellulose, lignin, and ash) and selective compounds of hydrochar and corresponding process liquor produced by hydrothermal carbonization (HTC) of maize silage. Several HTC reaction times and temperatures were applied and NIR spectra of both HTC solids and liquids were obtained and correlated with concentration determined from van-Soest fiber analysis, IC, and UHPLC. Partial least-squares regression was applied to calculate models for the prediction of selective substances. The model developed with the spectra had the best performance in 3–7 factors with a correlation coefficient, which varied between 0.9275–0.9880 and 0.9364–0.9957 for compounds in solid and liquid, respectively. Calculated root mean square errors of prediction (RMSEP) were 0.42–5.06 mg/kg. The preliminary results indicate that NIR, a widely applied technique, might be applied to determine chemical compounds in HTC solid and liquid.
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    Plasma-oxidative degradation of polyphenolics – Influence of non-thermal gas discharges with respect to fresh produce processing
    (Prague : ČSAZV, 2009) Grzegorzewski, F.; Schlüter, O.; Ehlbeck, J.; Weltmann, K.-D.; Geyer, M.; Kroh, L.W.; Rohn, S.
    Non-thermal plasma treatment is a promising technology to enhance the shelf-life of fresh or minimaly processed food. An efficient inactivation of microorganisms comes along with a moderate heating of the treated surface. To elucidate the influence of highly reactive plasma-immanent species on the stability and chemical behaviour of phytochemicals, several polyphenolics were exposed to an atmospheric pressure plasma jet (APPJ). The selected flavonoids are ideal target compounds due to their antioxidant activity protecting cells against the damaging effects of reactive oxygen species such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals and peroxynitrite. Reactions were carried out at various radio-frequency voltages, using Ar as a feeding gas. Degradation was followed by reversed-phase high-performance liquid chromatography.
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    Optimierung solar unterstützter Trocknungsverfahren für landwirtschaftliche Produkte einschließlich integrierter hygroskopischer Kurzzeitspeicher : Schlußbericht
    (Potsdam : Leibniz-Institut für Agrartechnik und Bioökonomie, 2000) Fürll, Christian; Ziegler, Th.; Richter, I.-G.; Pecenka, R.; Maltry, W.; Gottschalk, K.; Müller, S.
    [no abstract available]
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    Vertical soil profiling using a galvanic contact resistivity scanning approach
    (Basel : MDPI, 2014) Pan, Luan; Adamchuk, Viacheslav I.; Prasher, Shiv; Gebbers, Robin; Taylor, Richard S.; Dabas, Michel
    Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep) soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument.
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    Rationalisierungen im Melkstall – Chancen und Risiken
    (Darmstadt : KTBL, 2012) Jakob, Martina; Thinius, Maxi
    Steigende Herdengrößen haben den Arbeitsplatz im Melkstall verändert. Typische Folgen von Rationalisierung wie die arbeitsteilige Produktionsorganisation, hohe Durchsatzleistungen und Schichtarbeit lasten das Personal voll aus. Gleichzeitig ist eine hohe Rate an Beschwerden im Bereich des Muskel-Skelett-Systems bei den im Melkstall Beschäftigten zu verzeichnen. Frauen sind davon überdurchschnittlich betroffen. Eine genaue Analyse des Arbeitsplatzes gibt Hinweise auf notwendige Anpassungen der Arbeitsumgebung um die Gesundheitssituation der Beschäftigten langfristig zu verbessern.
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    Viertelindividuelle Vakuumapplikation für moderne Melksysteme
    (Darmstadt : KTBL, 2012) Ströbel, Ulrich; Rose-Meierhöfer, Sandra; Hoffmann, Gundula; Ammon, Christian; Amon, Thomas; Brunsch, Reiner
    Durch den Einsatz von viertelindividueller Melktechnik können die Bedingungen für Melkpersonal und Kühe erheblich verbessert werden. Die getrennte Schlauchführung für die Milch aus den vier Eutervierteln bietet deutliche Vorteile für die technische Weiterentwicklung dieser Melksysteme. Im Folgenden wird der Prototyp eines viertelindividuellen Melksystems mit Vakuumregelungseinheit vorgestellt, der eine milchflussabhängige, präzise Vakuumanpassung für jedes Euterviertel, verbunden mit einer hohen Rate von Sollwert-Istwert-Abgleichen durch die Regelungseinheit, ermöglicht.
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    Unraveling the microbiome of a thermophilic biogas plant by metagenome and metatranscriptome analysis complemented by characterization of bacterial and archaeal isolates
    (London : BioMed Central, 2016) Maus, Irena; Koeck, Daniela E.; Cibis, Katharina G.; Hahnke, Sarah; Kim, Yong S.; Langer, Thomas; Kreube, Jana; Erhard, Marcel; Bremges, Andreas; Off, Sandra; Stolze, Ivonne; Jaenicke, Sebastian; Goesmann, Alexander; Sczyrba, Alexander; Scherer, Paul; König, Helmut; Schwarz, Wolfgang H.; Zverlov, Vladimir V.; Liebl, Wolfgang; Pühler, Alfred; Schlüter, Andreas; Klocke, Michael
    One of the most promising technologies to sustainably produce energy and to mitigate greenhouse gas emissions from combustion of fossil energy carriers is the anaerobic digestion and biomethanation of organic raw material and waste towards biogas by highly diverse microbial consortia. In this context, the microbial systems ecology of thermophilic industrial-scale biogas plants is poorly understood.
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    Field inter-comparison of eleven atmospheric ammonia measurement techniques
    (München : European Geopyhsical Union, 2010) von Bobrutzki, K.; Braban, C.F.; Famulari, D.; Jones, S.K.; Blackall, T.; Smith, T.E.L.; Blom, M.; Coe, H.; Gallagher, M.; Ghalaieny, M.; McGillen, M.R.; Percival, C.J.; Whitehead, J.D.; Ellis, R.; Murphy, J.; Mohacsi, A.; Pogany, A.; Junninen, H.; Rantanen, S.; Sutton, M.A.; Nemitz, E.
    Eleven instruments for the measurement of ambient concentrations of atmospheric ammonia gas (NH3), based on eight different measurement methods were inter-compared above an intensively managed agricultural field in late summer 2008 in Southern Scotland. To test the instruments over a wide range of concentrations, the field was fertilised with urea midway through the experiment, leading to an increase in the average concentration from 10 to 100 ppbv. The instruments deployed included three wet-chemistry systems, one with offline analysis (annular rotating batch denuder, RBD) and two with online-analysis (Annular Denuder sampling with online Analysis, AMANDA; AiRRmonia), two Quantum Cascade Laser Absorption Spectrometers (a large-cell dual system; DUAL-QCLAS, and a compact system; c-QCLAS), two photo-acoustic spectrometers (WaSul-Flux; Nitrolux-100), a Cavity Ring Down Spectrosmeter (CRDS), a Chemical Ionisation Mass Spectrometer (CIMS), an ion mobility spectrometer (IMS) and an Open-Path Fourier Transform Infra-Red (OP-FTIR) Spectrometer. The instruments were compared with each other and with the average concentration of all instruments. An overall good agreement of hourly average concentrations between the instruments (R2>0.84), was observed for NH3 concentrations at the field of up to 120 ppbv with the slopes against the average ranging from 0.67 (DUAL-QCLAS) to 1.13 (AiRRmonia) with intercepts of −0.74 ppbv (RBD) to +2.69 ppbv (CIMS). More variability was found for performance for lower concentrations (<10 ppbv). Here the main factors affecting measurement precision are (a) the inlet design, (b) the state of inlet filters (where applicable), and (c) the quality of gas-phase standards (where applicable). By reference to the fast (1 Hz) instruments deployed during the study, it was possible to characterize the response times of the slower instruments.
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    Impact of chars and readily available carbon on soil microbial respiration and microbial community composition in a dynamic incubation experiment
    (Amsterdam : Elsevier, 2016) Lanza, Giacomo; Rebensburg, Philip; Kern, Jürgen; Lentzsch, Peter; Wirth, Stephan
    The carbonisation of biomass and organic residues is discussed as an opportunity to store stabilised carbon compounds in soil and to reduce mineralisation and the emission of CO2. In this study, pyrolysis char (600 °C, 30 min) and hydrothermal carbonisation char (HTC char; 210 °C, 23 bar, 8 h), both derived from maize silage, were investigated in a short-term incubation experiment of soil mixtures with or without readily available carbon (glucose) in order to reveal impacts on soil microbial respiration and community composition. In contrast to pyrolysis char, the addition of HTC char increased respiration and enhanced the growth of fungi. The addition of glucose to soil-char mixtures containing either pyrolysis or HTC char induced an additional increase of respiration, but was 35% and 39% lower compared to soil-glucose mixtures, respectively, providing evidence for a negative priming effect. No significant difference was observed comparing the soil mixtures containing pyrolysis char + glucose and HTC char + glucose. The addition of glucose stimulated the growth of most microbial taxa under study, especially of Actinobacteria at the expense of fungi. Adding pyrolysis or HTC char to soil induced a decline of all microbial taxa but did not modify the microbial community structure significantly. Addition of pyrolysis or HTC char in combination with glucose however, increased the abundance of Actinobacteria and reduced the relative abundance of Acidobacteria and Betaproteobacteria while fungi were further increased in case of HTC char. We conclude that both chars hold the potential to bring about specific impacts on soil microbial activities and microbial community structure, and that they may compensate the variations induced by the addition of readily available carbon.