1,562 research outputs found
Baldrianpräparate im Vergleich mit verschiedenen Phosphatdüngern im Grünland
Der Beitrag erläutert einen Versuch zur Phosphatversorgung im ökologischen Landbau. Erste Ergebnisse des auf fünf Jahre angelegten Feldversuches zeigen keine signifikanten Unterschiede der verschiedenen Varianten. Auffallend ist jedoch die erhöhte Zunahme des Kräuteranteils in den mit Baldrianpräparat gedüngten Varianten
Wie wirken die biologisch-dynamischen Präparate im Grünland?
Der Bericht zeigt die Ergebnisse eines zweijährigen Grünlandversuches zu der Wirkung biologisch-dynamischer Präparate auf. Neben der stoffbasierten Analyse aus der Qualitätsforschung, welche keine gesicherten Unterschiede der Varianten lieferte, konnte durch die Anwendung der bildschaffenden Methoden eine höhere Vitalität der mit Präparaten versehenen Varianten dargestellt werden
Biogasgülle, Boden und Lebensmittelqualität - Wirkung der Biogas-Reststoffsuspension auf Bodenfruchtbarkeit und Nahrungsqualität
Die Zielstellung des Versuchs war es, in einem Demeter-Betrieb den Einfluss einer Biogasgülledüngung im Vergleich zu anderen Düngevarianten auf die Bodenfruchtbarkeit und die Nahrungsqualität zu untersuchen. Nach vier Jahren Versuchsdauer zeigten sich bei einigen Parametern für Bodenfurchtbarkeit teils signifikante, teils tendenzielle Unterschiede. Es wäre wünschenswert gewesen, den Versuch längere Zeit laufen zu lassen, da sich deutliche Änderungen am Boden in der Regel, gleich um welche Veränderung der Bewirtschaftung (Bodenbearbeitung, Düngung, Fruchtfolge)es sich handelt, erst nach sieben Jahren zu erwarten sind. Bei den Nährelementgehalten des Korns bzw. des Kleegrases gibt es keine Unterschiede, die in irgendeine Richtung deuten. Bei Erträgen und Inhaltsstoffen zu Back- bzw. Futterqualität tauchen Signifikanzen nur bei deutlich niedrigeren Werten der Kontrolle auf.
Die Güllevarianten sind nicht wirklich zu differenzieren, was sich ähnlich bei MÖLLER et al. 2008 für Vieh haltende biologische wirtschaftende Betriebe findet.
Ein vergleichbares Bild zeigt sich bei Anwendung der verschiedensten Methoden, Nahrungsqualität nicht als Ausdruck von Inhaltsstoffen sondern als Signatur im Lebendigen zu erfassen. Alle Methoden, bei denen die Proben verblindet wurden, konnten keine eindeutige Zuordnung insbesondere der Güllevarianten herstellen.
Einzig bei den Analysen, bei denen auf Verblindung verzichtet wurde, diskriminierte sich die Biogasgüllevariante mehr oder weniger deutlich von den anderen Varianten. Die sehr uneindeutigen Ergebnisse der vorliegenden Versuchsreihe könnte damit zu erklären sein, dass auf einem Boden, der über 20 Jahre biologisch-dynamisch bewirtschaftet wurde, mehr als nur vier Jahre notwendig sind, bis sich eindeutige Ergebnisse herauskristallisieren. Auch im DOK-Versuch waren die Unterschiede der Varianten erst nach 20 Jahren Versuchsdauer eindeutig in eine Richtung zu differenzieren.
Um die Ausgangsfragestellung zu beantworten, wäre es sinnvoll, Vergleichspaare von Betrieben mit normaler Gülle und Biogasgülle parallel zu untersuchen. An der Bodenbiologie in der Universität Kassel wurde unter Prof. Jörgensen eine solche Untersuchung 2010 begonnen
Optical second-harmonic effect of sol-gel inorganic-organic nanocomposites
Communications: Second-order nonlinear optically (NLO) active materials have promising technical applications in optoelectronic devices. A general problem in NLO-active polymeric systems is the decay of orientational order with time. Results are presented which show that using inorganic-organic composite materials produced by the sol-gel process as a rigid matrix for oriented ÷(2) chromophores (Figure) may provide a means of overcoming this problem
A Duna-Tisza közi talajvíz és a szikes tóvizek hidrogeológiai, hidrodinamikai és hidrokémiai viszonyainak összefüggése a karbonátképződésükkel = Hydrogeology and carbonate mineralization
A dolomit laboratóriumban 100 fok C alatt nem állíthatókelő. A Duna--Tisza közi szikes tavak vizéből, amelyeknek vízhőmérséklete legfeljebb 37 C fokot ér el, dolomit is kiválik. Keletkezésük vízi hátrere részletesen eddig ismeretlen volt. Ezért kilenc helyről több mint három éven át havi vízminták elemzésére került sor. A vizek pH értéke 6,9--9,7, redoxpotenciálja általában 0-- -160, összsó-mennyisége 500--14 000 0mg/l, nátrium-tartalma 0,5--3600 mg/l között változik. A vizek nátriumk-kalcium-magnézium hidrokarbonátosak. Evaporációjukat stabil-izotóp elemzésekkel igazoltuk. Dolomitképződési szempontból fontos magnézium/kalcium arány az evaporációval emelkedik, a CaCO3/Ca arány pedig minden esetben elősegití a dolomitképződést. A dolomit szénradioizotóp elemzések alapján a teljes holocénben képződött. | Dolomite can not be artifically produced in a lab under 100 degrees C. Conversely, in the lakes of the Danube-Tisza Interfluve, in Central Hungary, where water temperatures are not higher than 37 degrees C, dolomite precipitation is and was rather common. The formation of dolomite in these lakes with the underlying reasons unknown so far. To find an answer to a period of 3 consecutive years. The recorded pH of the collected waters was 6.9--9.7,with a redox potential of 0-- -160, a total salt of 500--14 000 mg/l and Na content of 0.5--3500 mg/l. The waters are potassium, calcium, magnesium hydrocarbonate bearing. Their evaporation was justified by stable isotopic studies. In case of doloite formation, the Mg/Ca ratio tends to inrease with the strengthening of evaporation, the yielding CaCO3/Ca ratio promotes dolomite precipitation
Energy Efficient Excavator Functions Based on Electro-hydraulic Variable-speed Drive Network
Electrification of mobile working machines is subject to increasing focus in both industry andacademia. At this stage, focus has been the replacement of conventional internal combustion engineswith cable or battery fed electric motors driving the main pump(s), and the replacement of rotaryfunctions with electro-mechanical drive solutions. However, the linear functions remain controlledby hydraulic control valves resulting in substantial throttle losses, which in turn necessitates largebattery sizes and/or low machine uptimes. Alternatively, the valve-controlled hydraulic cylinders maybe replaced with electro-mechanical solutions in applications with limited forces, whereas heavy dutyworking machines such as medium/large excavators may benefit from standalone electro-hydraulicprimary controlled drives, i.e., variable-speed standalone drives. The use of such solutions willsubstantially increase efficiency due to the absent/limited throttle control and the ability to sharepower through the electric supply/DC-bus. A main drawback is that each axis needs to be designedto meet both the maximum force and maximum speed, hence in the case of using single motorstandalone drives, each motor and associated inverter needs to be designed to meet both the maximumforce and maximum speed, potentially rendering these somewhat large. Alternatively, dual motorstandalone drives can be applied, enabling power distribution via more motors. However, the use ofnumerous motors requires more extensive system integration and potentially large motor powerinstallations considering industrially available non-specialized components. This paper presents anovel so-called electro-hydraulic variable-speed drive network, applied for actuation of three linearfunctions of an excavator implement. Cylinder chamber short-circuiting’s and electro-hydraulicvariable-speed units constitute a drive network allowing both electric and hydraulic power sharing.The drive network is realized with Bosch Rexroth A2 displacement units and eLION electric motorsas its core components. Results demonstrate that the proposed drive network is realizable with similarenergy efficiency as a standalone dual motor electro-hydraulic drive solution, but with less motorpower and with fewer motors, displacement units and integration effort, rendering this a moresustainable and cost-efficient solution. Finally, it is shown that the proposed drive network is superiorin terms of installed displacement, electric motor power and energy efficiency, compared to a separatemetering valve drive supplied by a battery fed electro-hydraulic pump
Case report of long-term postural tachycardia syndrome in a patient after messenger RNA coronavirus disease-19 vaccination with mRNA-1273
BACKGROUND
Postural tachycardia syndrome (POTS) is characterized by orthostatic intolerance and heart rate increase in an upright position without orthostatic hypotension. It has been described after coronavirus disease-19 (COVID-19) as well as after COVID-19 vaccination.
CASE SUMMARY
A 54-year-old female patient presented with a 9-months history of severe orthostatic intolerance since COVID-19 vaccination with messenger RNA (mRNA)-1273 (Spikevax, Moderna). Except for diet-controlled coeliac disease, the patient was healthy, had no allergies, and did not take regular medication. Tilt table testing revealed a significant heart rate increase to 168 bpm without orthostatic hypotension accompanied by light-headedness, nausea, and syncope, findings consistent with POTS. Potential underlying causes including anaemia, thyroid dysfunction, adrenal insufficiency, pheochromocytoma, (auto)-immune disease, chronic inflammation as well as neurological causes were ruled out. Echocardiography and cardiac stress magnetic resonance imaging (MRI) did not detect structural or functional heart disease or myocardial ischaemia. Forty-eight-hour-electrocardiogram (ECG) showed no tachycardias other than sinus tachycardia. Finally, genomic analysis did not detect an inherited arrhythmia syndrome. Serologic analysis revealed adequate immune response to mRNA-1273 vaccination without signs of previous severe acute respiratory syndrome-coronavirus-2 infection. While ivabradine was not tolerated and metoprolol extended release only slightly improved symptoms, physical exercise reduced orthostatic intolerance moderately. At a 5-months follow-up, the patient remained dependant on assistance for activities of daily living.
DISCUSSION
The temporal association of POTS with the COVID-19 vaccination in a previously healthy patient and the lack of evidence of an alternative aetiology suggests COVID-19 vaccination is the potential cause of POTS in this patient. To our knowledge, this is the first case reporting severe, long-term, and treatment-refractory POTS following COVID-19 vaccination with mRNA1273
Mineralogical, geochemical and isotopic characteristics of hydrothermal alteration processes in the active, submarine, felsic-hosted PACMANUS field, Manus Basin, Papua New Guinea
During ODP Leg 193, 4 sites were drilled in the active PACMANUS hydrothermal field on the crest of the felsic Pual Ridge to examine the vertical and lateral variations in mineralization and alteration patterns. We present new data on clay mineral assemblages, clay and whole rock chemistry and clay mineral strontium and oxygen isotopic compositions of altered rocks from a site of diffuse low-temperature venting (Snowcap, Site 1188) and a site of high-temperature venting (Roman Ruins, Site 1189) in order to investigate the water-rock reactions and associated elemental exchanges. The volcanic succession at Snowcap has been hydrothermally altered, producing five alteration zones: (1) chlorite +/- illite-cristobalite-plagioclase alteration apparently overprinted locally by pyrophyllite bleaching at temperatures of 260-310degreesC; (2) chlorite +/- mixed-layer clay alteration at temperatures of 230degreesC; (3) chlorite and illite alteration; (4) illite and chlorite +/- illite mixed-layer alteration at temperatures of 250-260degreesC; and (5) illite +/- chlorite alteration at 290-300degreesC. Felsic rocks recovered from two holes (1189A and 1189B) at Roman Ruins, although very close together, show differing alteration features. Hole 1189A is characterized by a uniform chlorite-illite alteration formed at similar to250degreesC, overprinted by quartz veining at 350degreesC. In contrast, four alteration zones occur in Hole 1189B: (1) illite chlorite alteration formed at similar to300degreesC; (2) chlorite +/- illite alteration at 235degreesC; (3) chlorite illite and. mixed layer clay alteration; and (4) chlorite illite alteration at 220degreesC. Mass balance calculations indicate that the chloritization, illitization and bleaching (silica-pyrophyllite assemblages) alteration stages are accompanied by different chemical changes relative to a calculated pristine precursor lava. The element Cr appears to have a general enrichment in the altered samples from PACMANUS. The clay concentrate data show that Cr and Cu are predominantly present in the pyrophyllites. Illite shows a significant enrichment for Cs and Cu relative to the bulk altered samples. Considerations of mineral stability allow us to place some constraints on fluid chemistry. Hydrothermal fluid pH for the chloritization and illitization was neutral to slightly acidic and relatively acidic for the pyrophyllite alteration. In general the fluids, especially from Roman Ruins and at intermediate depths below Snowcap, show only a small proportion of seawater mixing (<10%). Fluids in shallow and deep parts of the Snowcap holes, in contrast, show stronger seawater influence. Copyright (C) 2004 Elsevier Ltd
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