344 research outputs found
Impact of climate change on N-cycle and greenhouse gas fluxes in alpine grassland ecosystems: an in situ climate change experiment
What can we learn from long-term measurements of soil-atmosphere exchange of trace gases? The Höglwald as a case study
Impact of clear-cutting and selective cutting on the soil-atmosphere greenhouse gas exchange of an N-saturated spruce forest in the course of its conversion to a mixed deciduous forest
FLOW PATTERNS OF THE ESTER OIL-REFRIGERANT R134A MIXTURE FLASHING FLOW THROUGH A SMALL DIAMETER TUBE
This work presents an experimental investigation of the ester oil ISO VG10-refrigerant R134a mixture flashing flow with foam formation through a straight horizontal 3.22 mm-diameter-6.0 m- long tube. An experimental apparatus was designed to allow the measurement of both pressure and temperature profiles along the tube as well as the visualization of the flow patterns. Tests were performed at different mass flow rates, several refrigerant mass fractions at the inlet of the flow, and inlet mixture temperatures around 28 and 39 °C. A liquid mixture flow with constant temperature and pressure gradient could be noticed at the inlet of the tube. As the flow proceeded towards the exit of the tube the pressure drop produced a reduction of the refrigerant solubility in the oil yielding to formation of the first bubbles. Initially, small and few bubbles could be noticed and the flow behaved as a conventional two-phase flow. Eventually, the bubble population increased and foam flow was observed at the exit of the tube. Due to the great formation of bubbles, both the temperature and pressure gradient of the mixture were greatly reduced in this region of the flow
Electronic structure and x-ray magnetic dichroism in random substitutional alloys of f-electron elements
The Koringa-Kohn-Rostoker —coherent-potential-approximation method combines multiple-scattering theory and the coherent-potential approximation to calculate the electronic structure of random substitutional alloys of transition metals. In this paper we describe the generalization of this theory to describe f-electron alloys. The theory is illustrated with a calculation of the electronic structure and magnetic dichroism curves for a random substitutional alloy containing rare-earth or actinide elements from first principles
Mikrobielle Stickstoff-Umwetzungen in Mini-Lysimetern in einem in situ-Klimaänderungsexperiment (FORKAST)
Surface flux estimates derived from UAS-based mole fraction measurements by means of a nocturnal boundary layer budget approach
Halley's comet of 87 BC on the coins of Armenian king Tigranes?
Coins of Armenian king Tigranes II the Great (95-55 BC), silver and
copper-bronze tetradrachms and drachms, clearly reveal a star with a tail on
the royal tiara which may be associated with the Halley's comet passage of 87
BC. If so, one has another case when astronomical events can be useful for
historical chronological problems, this would be a far earlier record of Halley
in Armenia than was previously known from chronicles and also one of the
earliest known images of Halley's comet.Comment: The published version. The photos of coins are subject of copyright
and can be used only upon permission of the first autho
Standardized EEG interpretation accurately predicts prognosis after cardiac arrest.
OBJECTIVE: To identify reliable predictors of outcome in comatose patients after cardiac arrest using a single routine EEG and standardized interpretation according to the terminology proposed by the American Clinical Neurophysiology Society.
METHODS: In this cohort study, 4 EEG specialists, blinded to outcome, evaluated prospectively recorded EEGs in the Target Temperature Management trial (TTM trial) that randomized patients to 33°C vs 36°C. Routine EEG was performed in patients still comatose after rewarming. EEGs were classified into highly malignant (suppression, suppression with periodic discharges, burst-suppression), malignant (periodic or rhythmic patterns, pathological or nonreactive background), and benign EEG (absence of malignant features). Poor outcome was defined as best Cerebral Performance Category score 3-5 until 180 days.
RESULTS: Eight TTM sites randomized 202 patients. EEGs were recorded in 103 patients at a median 77 hours after cardiac arrest; 37% had a highly malignant EEG and all had a poor outcome (specificity 100%, sensitivity 50%). Any malignant EEG feature had a low specificity to predict poor prognosis (48%) but if 2 malignant EEG features were present specificity increased to 96% (p < 0.001). Specificity and sensitivity were not significantly affected by targeted temperature or sedation. A benign EEG was found in 1% of the patients with a poor outcome.
CONCLUSIONS: Highly malignant EEG after rewarming reliably predicted poor outcome in half of patients without false predictions. An isolated finding of a single malignant feature did not predict poor outcome whereas a benign EEG was highly predictive of a good outcome
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