1,418 research outputs found
Dissolved reactive phosphorus in runoff assessed by soil extraction with an acetate buffer
Agronomic soil test phosphorus (STP) data is, in addition to fertility studies, increasingly utilised in environmental risk assessment. We compared relationships between soil P extracted by acid ammonium acetate (AAAc-P) and water-soluble P (Pw) in laboratory, and AAAc-P and dissolved molybdatereactive P (DRP) in field runoff. The laboratory study suggested a close relationship (R2 = 0.87, n = 64) between AAAc-P and soluble P concentration in 1:100 (w/v) soil-to-water extracts, described by a linear equation:Pw (mg l1) =0.021 × AAAc-P (mg l1 soil) 0.015 (mg l1). In Lake Rehtijärvi cathcment, dominated by clayey soils, the AAAc-P content of field Ap horizon in a similar manner influenced the flow-weighted DRP concentration in surface runoff and drainflow:a 1 mg l1 increase in soil AAAc-P corresponded to 0.015 and 0.018 mg l1 increase in surface runoff and drainflow DRP, respectively. When the AAAc-P vs.Pw relationship obtained in the laboratory test was used to predict the average DRP concentration in edge-of-field runoff, the precision of the DRP estimates inferred from STP data was in 95% of the cases ± 0.10 mg l1. In the L. Rehtijärvi catchment, 50% of the diffuse DRP loading risk was assigned to an area that corresponded to less than 20% of the fields and the situation may be similar in the national scale.;Neuvonnallisessa maa-analyysissä käytetyt fosforin uutot voidaan jakaa karkeasti niihin, joilla arvioidaan maan helppoliukoisen fosforin pitoisuutta ja niihin, joilla arvioidaan pitkän ajan kuluessa kasvien käyttöön vapautuvan fosforin kokonaismäärää. Maan helppoliukoiset fosforivarannot ovat keskeisiä pellolta valuvaan veteen liukenevan fosforin kannalta. Suomessa käytössä olevalla maa-analyysimenetelmällä,uutto happamalla ammoniumasetaattipuskurilla, arvioidaan juuri helppoliukoisia fosforivarantoja, ja teoreettiselta kannalta kansallinen menetelmämme saattaa siten soveltua valumavesien liuenneen fosforin pitoisuuden ennustamiseen. Tässä työssä tutkittiin happamaan asetaattiliuokseen uuttuvan fosforin määrän (maa-analyysin fosforiluku) ja veteen liukenevan fosforin välistä yhteyttä laboratoriossa ja peltokokeessa. Laboratoriossa maa-analyysin fosforiluku ja veteen liukenevan fosforin määrä olivat selkeästi yhteydessä toisiinsa, eikä maan orgaanisen hiilen pitoisuus, maan happamuus tai maalaji vaikuttanut tähän yhteyteen. Jokioisten Rehtijärven valuma-alueella (pääosin hiuesavimaita) tehdyissä kenttä mittauksissa maa-analyysin fosforiluvun ja valumavesiin liuenneen fosforin keskimääräisen valumapainotteisen pitoisuuden välillä havaittiin lähes samanlainen yhteys. Valumavesien liuenneen fosforin keskimääräinen pitoisuus voitiin 95 % tapauksista ennustaa ±0,10 mg/l tarkkuudella laboratoriokokeista saadun yhtälön avulla. Yhtälö hieman yliarvioi liuenneen fosforin pitoisuutta peltovalumavesissä, erityisesti suuremmissa fosforipitoisuuksissa. Puolet Rehtijärven valuma-alueella liuenneen fosforin huuhtoumasta saattaa tulla ainoastaan 20 % iljelyalalta. Viljavuuspalvelussa vuosina 1995-1998 tehtyjen määritysten fosforiluvun jakauman perusteella tilanne saattaa olla samankaltainen koko maassa
On the IRS Deployment in Smart Factories Considering Blockage Effects: Collocated or Distributed?
In this article, we study the collocated and distributed deployment of
intelligent reflecting surfaces (IRS) for a fixed total number of IRS elements
to support enhanced mobile broadband (eMBB) and ultra-reliable low-latency
communication (URLLC) services inside a factory. We build a channel model that
incorporates the line-of-sight (LOS) probability and power loss of each
transmission path, and propose three metrics, namely, the expected received
signal-to-noise ratio (SNR), expected finite-blocklength (FB) capacity, and
expected outage probability, where the expectation is taken over the
probability distributions of interior blockages and channel fading. The
expected received SNR and expected FB capacity for extremely high blockage
densities are derived in closed-form as functions of the amount and height of
IRSs and the density, size, and penetration loss of blockages, which are
verified by Monte Carlo simulations. Results show that deploying IRSs
vertically higher leads to higher expected received SNR and expected FB
capacity. By analysing the average/minimum/maximum of the three metrics versus
the number of IRSs, we find that for high blockage densities, both eMBB and
URLLC services benefit from distributed deployment; and for low blockage
densities, URLLC services benefit from distributed deployment while eMBB
services see limited difference between collocated and distributed deployment
Performance and flow dynamics studies of polymeric optofluidic sers sensors
We present a polymer-based optofluidic surface enhanced Raman scattering chip for biomolecule detection, serving as a disposable sensorchoice with cost-effective production. The SERS substrate is fabricated by using industrial roll-to-roll UV-nanoimprinting equipment andintegrated with adhesive-based polymeric microfluidics. The functioning of the SERS detection on-chip is confirmed and the effect of thepolymer lid on the obtainable Raman spectra is analysed. Rhodamine 6G is used as a model analyte to demonstrate continuous flowmeasurements on a planar SERS substrate in a microchannel. The relation between the temporal response of the sensors and sample flowdynamics is studied with varied flow velocities, using SERS and fluorescence detection. The response time of the surface-dependent SERSsignal is longer than the response time of the fluorescence signal of the bulk flow. This observation revealed the effect of convection on thetemporal SERS responses at 25 μl/min to 1000 μl/min flow velocities. The diffusion of analyte molecules from the bulk concentration intothe sensing surface induces about a 40-second lag time in the SERS detection. This lag time, and its rising trend with slower flow velocities, has to be taken into account in future trials of the optofluidic SERS sensor, with active analyte binding on the sensing surface
Bridging the gap between policy and science in assessing the health status of marine ecosystems
Human activities, both established and emerging, increasingly affect the provision of marine ecosystem services that deliver societal and economic benefits. Monitoring the status of marine ecosystems and determining how human activities change their capacity to sustain benefits for society requires an evidence-based Integrated Ecosystem Assessment approach that incorporates knowledge of ecosystem functioning and services). Although, there are diverse methods to assess the status of individual ecosystem components, none assesses the health of marine ecosystems holistically, integrating information from multiple ecosystem components. Similarly, while acknowledging the availability of several methods to measure single pressures and assess their impacts, evaluation of cumulative effects of multiple pressures remains scarce. Therefore, an integrative assessment requires us to first understand the response of marine ecosystems to human activities and their pressures and then develop innovative, cost-effective monitoring tools that enable collection of data to assess the health status of large marine areas. Conceptually, combining this knowledge of effective monitoring methods with cost-benefit analyses will help identify appropriate management measures to improve environmental status economically and efficiently. The European project DEVOTES (DEVelopment Of innovative Tools for understanding marine biodiversity and assessing good Environmental Status) specifically addressed t hese topics in order to support policy makers and managers in implementing the European Marine Strategy Framework Directive. Here, we synthesize our main innovative findings, placing these within the context of recent wider research, and identifying gaps and the major future challenges
Projected shell model study of odd-odd f-p-g shell proton-rich nuclei
A systematic study of 2-quasiparticle bands of the proton-rich odd-odd nuclei
in the mass A ~ 70-80 region is performed using the projected shell model
approach. The study includes Br-, Rb-, and Y-isotopes with N = Z+2, and Z+4. We
describe the energy spectra and electromagnetic transition strengths in terms
of the configuration mixing of the angular-momentum projected
multi-quasiparticle states. Signature splitting and signature inversion in the
rotational bands are discussed and are shown to be well described. A
preliminary study of the odd-odd N = Z nucleus, 74Rb using the concept of
spontaneous symmetry breaking is also presented.Comment: 14 pages, 7 figures, final version accepted by Phys. Rev.
Shape coexistence at the proton drip-line: First identification of excited states in 180Pb
Excited states in the extremely neutron-deficient nucleus, 180Pb, have been
identified for the first time using the JUROGAM II array in conjunction with
the RITU recoil separator at the Accelerator Laboratory of the University of
Jyvaskyla. This study lies at the limit of what is presently achievable with
in-beam spectroscopy, with an estimated cross-section of only 10 nb for the
92Mo(90Zr,2n)180Pb reaction. A continuation of the trend observed in 182Pb and
184Pb is seen, where the prolate minimum continues to rise beyond the N=104
mid-shell with respect to the spherical ground state. Beyond mean-field
calculations are in reasonable correspondence with the trends deduced from
experiment.Comment: 5 pages, 4 figures, submitted to Phys.Rev.
First observation of excited states in 173Hg
The neutron-deficient nucleus 173Hg has been studied following
fusion-evaporation reactions. The observation of gamma rays decaying from
excited states are reported for the first time and a tentative level scheme is
proposed. The proposed level scheme is discussed within the context of the
systematics of neighbouring neutron-deficient Hg nuclei. In addition to the
gamma-ray spectroscopy, the alpha decay of this nucleus has been measured
yielding superior precision to earlier measurements.Comment: 5 pages, 4 figure
Proton drip-line nuclei in relativistic mean-field theory
The position of the two-proton drip line has been calculated for even-even
nuclei with in the framework of the relativistic mean-field
(RMF) theory. The current model uses the NL3 effective interaction in the
mean-field Lagrangian and describes pairing correlations in the
Bardeen-Cooper-Schrieffer (BCS) formalism. The predictions of the RMF theory
are compared with those of the Hartree-Fock+BCS approach (with effective force
Skyrme SIII) and the finite-range droplet model (FRDM) and with the available
experimental information.Comment: 18 pages, RevTeX, 2 p.s figures, to appear in Phys. Rev.
- …