2,328 research outputs found

    Homiletics: Studies on the Old Testament Texts

    Get PDF
    Studies on the Old Testament Text

    Genetic variation for nutrient use efficiency in maize under different tillage and fertilization regimes with special emphasis to plant microbe interaction

    Get PDF
    Conservation tillage (no-till and reduced tillage) brings many benefits with respect to soil fertility and energy use, but it also has drawbacks regarding the need for synthetic fertilizers and herbicides. To promote conversation tillage in organic farming systems, crop rotation, fertilization and weed control have to be optimized. In addition, crop varieties are needed with improved nutrient use efficiency (NUE) and high weed competitiveness or tolerance

    Pilot Experiments with Electrodialysis and Ozonation for the Production of a Fertilizer from Urine

    Get PDF
    Pilot tests were performed with a process combination of electrodialysis and ozonation for the removal of micropollutants and the concentration of nutrients in urine. In continuous and batch experiments, maximum concentration factors up to 3.5 and 4.1 were obtained, respectively. The desalination capacity did not decrease significantly during continuous operation periods of several weeks. Membrane cleaning after 195 days resulted in approximately 35% increase in desalination rate. The Yeast Estrogen Screen (YES), a bioassay that selectively detects oestrogenic compounds, confirmed that about 90% of the oestrogenic activity was removed by electrodialysis. HPLC analysis showed that ibuprofen was removed to a high extent, while other micropollutants were below the detection limit. In view of the fact that ibuprofen is among the most rapidly transported micropollutants in electrodialysis processes, this result indicates that electrodialysis provides an effective barrier for micropollutants. Standardised plant growth tests were performed in the field with the salt solution resulting from the treatment by electrodialysis and subsequent ozonation. The results show that the plant height is comparable to synthetic fertilisers, but the crop yield is slightly lower. The latter is probably caused by volatilisation losses during field application, which can be prevented by improved application technologies

    TQM, ISO 9000, and Commissioning (Let's Be Practical)

    Get PDF
    Diversity between building projects and construction methods is such that it is not possible to evoke a single phrase, commissioning, directly or conceptually and assume all building performance problems are solved. Commissioning has been defined as everything from a testing phase that concludes construction, to a quality management technique applied to a project from concept to turnover and beyond. Therefore, simply purchasing commissioning may not yield desired performance. A link is needed that ties managing performance to the process that verifies achievement of defined performance goals. That link may be certification. TQM (total quality management) was developed by W. Edwards Deming to assist in creating a management environment that would yield consistent performance. International Standards Organization (ISO) applies discipline to that concept requiring a structured well-documented management environment capable of withstanding an audit. One could quickly build a library in the study of management techniques devoted to achieving performance: Peter Drucker (Management by Objectives), Tom Peters (In Search of Excellence) and Stephen Covey (7 Habits) just to name a few. This may be the path to certification. This presentation is intended to provide an overview of the relationship between recognized quality management techniques and commissioning. Specifically it will deal with tying the quality certification process defined by ISO to commissioning as defined in ASHRAE GPC1- 1996. Questions that will be raised are: 1) Is it possible to certify a construction project to ISO standards? 2) Is it practical to certify a construction project to ISO standards? 3) Will a fully commissioned, ISO certified facility guarantee desired performance? It is the belief of this author that design-build projects are gaining momentum in the industry, battling only barriers of price versus performance. Imagine the power of an ISO certified Design-build Corporation that guaranteed not only price and schedule but also performance; specifically performance that exceeds traditional codes or standards

    Cenozoic paleoceanography 1986: An introduction

    Get PDF
    New developments in Cenozoic paleoceanography include the application of climate models and atmospheric general circulation models to questions of climate reconstruction, the refinement of conceptual models for interpretation of the carbon isotope record in terms of carbon mass balance, paleocirculation, paleoproductivity, and the regional mapping of paleoceanographic events by acoustic stratigraphy. Sea level change emerges as a master variable to which changes in the ocean environment must be traced in many cases, and tests of the onlap-offlap paradigm therefore are of crucial importance

    Evolution of leaf-form in land plants linked to atmospheric CO2 decline in the Late Palaeozoic era

    Get PDF
    The widespread appearance of megaphyll leaves, with their branched veins and planate form, did not occur until the close of the Devonian period at about 360 Myr ago. This happened about 40 Myr after simple leafless vascular plants first colonized the land in the Late Silurian/Early Devonian, but the reason for the slow emergence of this common feature of present-day plants is presently unresolved. Here we show, in a series of quantitative analyses using fossil leaf characters and biophysical principles, that the delay was causally linked with a 90% drop in atmospheric pCO2 during the Late Palaeozoic era. In contrast to simulations for a typical Early Devonian land plant, possessing few stomata on leafless stems, those for a planate leaf with the same stomatal characteristics indicate that it would have suffered lethal overheating, because of greater interception of solar energy and low transpiration. When planate leaves first appeared in the Late Devonian and subsequently diversified in the Carboniferous period, they possessed substantially higher stomatal densities. This observation is consistent with the effects of the pCO2 on stomatal development and suggests that the evolution of planate leaves could only have occurred after an increase in stomatal density, allowing higher transpiration rates that were sufficient to maintain cool and viable leaf temperatures

    Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO3_3/SrTiO3_3 heterostructures

    Full text link
    We present a detailed study of the Ti 3dd carriers at the interface of LaAlO3_3/SrTiO3_3 heterostructures by high-resolution resonant inelastic soft x-ray scattering (RIXS), with special focus on the roles of overlayer thickness and oxygen vacancies. Our measurements show the existence of interfacial Ti 3dd electrons already below the critical thickness for conductivity and an increase of the total interface charge up to a LaAlO3_3 overlayer thickness of 6 unit cells before it levels out. By comparing stoichiometric and oxygen deficient samples we observe strong Ti 3dd charge carrier doping by oxygen vacancies. The RIXS data combined with photoelectron spectroscopy and transport measurements indicate the simultaneous presence of localized and itinerant charge carriers. However, it is demonstrated that the relative amount of localized and itinerant Ti 3d3d electrons in the ground state cannot be deduced from the relative intensities of the Raman and fluorescence peaks in excitation energy dependent RIXS measurements, in contrast to previous interpretations. Rather, we attribute the observation of either the Raman or the fluorescence signal to the spatial extension of the intermediate state reached in the RIXS excitation process.Comment: 9 pages, 6 figure

    Profiling the interface electron gas of LaAlO3/SrTiO3 heterostructures by hard X-ray photoelectron spectroscopy

    Full text link
    The conducting interface of LaAlO3_3/SrTiO3_3 heterostructures has been studied by hard X-ray photoelectron spectroscopy. From the Ti~2pp signal and its angle-dependence we derive that the thickness of the electron gas is much smaller than the probing depth of 4 nm and that the carrier densities vary with increasing number of LaAlO3_3 overlayers. Our results point to an electronic reconstruction in the LaAlO3_3 overlayer as the driving mechanism for the conducting interface and corroborate the recent interpretation of the superconducting ground state as being of the Berezinskii-Kosterlitz-Thouless type.Comment: 4 pages, 4 figure

    Calculating the balance between atmospheric CO2 drawdown and organic carbon oxidation in subglacial hydrochemical systems

    Get PDF
    In order to constrain CO2 fluxes from biogeochemical processes in subglacial environments, we model the evolution of pH and alkalinity over a range of subglacial weathering conditions. We show that subglacial waters reach or exceed atmospheric pCO2 levels when atmospheric gases are able to partially access the subglacial environment. Subsequently, closed system oxidation of sulfides is capable of producing pCO2 levels well in excess of atmosphere levels without any input from the decay of organic matter. We compared this model to published pH and alkalinity measurements from 21 glaciers and ice sheets. Most subglacial waters are near atmospheric pCO2 values. The assumption of an initial period of open system weathering requires substantial organic carbon oxidation in only 4 of the 21 analyzed ice bodies. If the subglacial environment is assumed to be closed from any input of atmospheric gas, large organic carbon inputs are required in nearly all cases. These closed system assumptions imply that order of 10 g m−2 y−1 of organic carbon are removed from a typical subglacial environment—a rate too high to represent soil carbon built up over previous interglacial periods and far in excess of fluxes of surface deposited organic carbon. Partial open system input of atmospheric gases is therefore likely in most subglacial environments. The decay of organic carbon is still important to subglacial inorganic chemistry where substantial reserves of ancient organic carbon are found in bedrock. In glaciers and ice sheets on silicate bedrock, substantial long‐term drawdown of atmospheric CO2 occurs
    corecore