Search results for "Inflow"
showing 10 items of 37 documents
Unemployment Flows in Finland, 1969-95: A Time Series Analysis
1998
We adopt a flow approach to analyse Finnish unemployment experience during the last three decades. In addition to data on short-term and total outflow and inflow rates from a relatively long period beginning in 1969, we also have data on duration-specific outflow rates for the period 1984 I–96 II which encompasses the spectacular increase in unemployment in the early nineties. The empirical study shows that both the inflow and the outflow is mainly driven by variation in job opportunities. For a given vacancy-unemployment ratio, the outflow rate has fallen because of changes in unemployment compensation, demographic structure and emigration. The outflow has been only marginally affected by …
Value of the deep femoral artery as alternative inflow source in infrainguinal bypass surgery.
2013
Background The purpose of this study was to analyze the long-term results of infrainguinal bypass surgery using the deep femoral artery (DFA) as the inflow source. Methods Between 1998 and 2011, 88 bypasses of the lower limb were placed in 86 patients (mean age 71 years) using the deep femoral artery as inflow. Patients' records were retrieved from a computerized database and analyzed retrospectively. Results Critical limb ischemia (rest pain/tissue loss) was the indication in the majority (87.5%) of cases. The distal anastomosis of the bypass grafts was located at the popliteal level in 32 cases and the tibial (pedal) level in 52 cases, respectively, with the autologous vein as conduit in …
Burner backflow reduction in regeneration furnace
2011
In the present case from the steel industry, waste hydrochloric acid from the pickling process is regenerated using spray roasting. The process is driven by four burners placed symmetrically along the periphery of the cylindrical main section of the reactor. Severe problems with gas backflow and sintering of iron oxide inside the burner chamber have led to a complete shut down of the process 1-2 times every week, which is a frequency which significantly affects the productivity. In this study the influence of a kick-out on the gas flow in the vicinity of the burner chamber is investigated numerically. It is shown that the kick-out geometry creates a vortical low pressure region preventing t…
The effects of linearly increasing flip angles on 3D inflow MR angiography
1994
As recently demonstrated, spin saturation effects in 3D time-of-flight (TOF) MR angiography (MRA) can be reduced by using RF pulses with linearly increasing flip angles (ramp pulses) in the main direction of flow. We developed a model for calculating the signal distribution of proton flow within the excitation volume (slab) for different ramp slopes and compared the results with the measured distribution for the lower-leg arteries. The ramp pulses were generated using the Fourier transformation of the desired excitation profiles. With a bandwidth of 6 kHz and a pulse length of 2.56 ms satisfactory ramps with variable slopes were generated and applied in a standard flow-compensated 3D FISP s…
Hydropower Optimization Using Deep Learning
2019
This paper demonstrates how deep learning can be used to find optimal reservoir operating policies in hydropower river systems. The method that we propose is based on the implicit stochastic optimization (ISO) framework, using direct policy search methods combined with deep neural networks (DNN). The findings from a real-world two-reservoir hydropower system in southern Norway suggest that DNNs can learn how to map input (price, inflow, starting reservoir levels) to the optimal production pattern directly. Due to the speed of evaluating the DNN, this approach is from an operational standpoint computationally inexpensive and may potentially address the long-standing problem of high dimension…
Littoral Demosponges from the Banks of the Strait of Sicily and the Alboran Sea
1987
The material of this study has been collected from the South-Western Mediterranean in the course of two expeditions by the Italian Research Vessel “Bannock”. The primary collection method employed was SCUBA diving. The sampled area is affected by an important inflow of water from the Atlantic. Fifty-nine species have been studied. One of them, Stylostichon equiosculatus, is new to science. Some ecological considerations are also discussed.
Problems Involved in the Measurement of Microcirculation by Means of Microelectrodes
1973
Until now, the interpretation of local wash-out curves, measured by means of microelectrodes and using hydrogen as diffusible indicator, is an unsettled problem. It has been shown, that even the simultaneous measurement by means of a surface-multiwire-Pt-microelectrode at the isolated and hemoglobin-free perfused rat liver yields different wash-out curves (4). These differences occur with regard to the height of the curves as well as to the moment, when the maximum of the indicator’s concentration is seen by the microelectrode. Fig.1 represents four simultaneously recorded curves. The difference in sensitivity of each micro-electrode has been compensated by a computer. The fast curve corres…
Modeling of perched leachate zone formation in municipal solid waste landfills.
2010
The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model was based on mass balance equations, that enable simulation of the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the inflow to and outflow from each layer as well as the continuous moisture distribution. The infiltration flow was evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solu…
On the Azimuthal Stability of Shock Waves around Black Holes
1998
Analytical studies and numerical simulations of time dependent axially symmetric flows onto black holes have shown that it is possible to produce stationary shock waves with a stable position both for ideal inviscid and for moderately viscous accretion disks. We perform several two dimensional numerical simulations of accretion flows in the equatorial plane to study shock stability against non-axisymmetric azimuthal perturbations. We find a peculiar new result. A very small perturbation seems to produce an instability as it crosses the shock, but after some small oscillations, the shock wave suddenly transforms into an asymmetric closed pattern, and it stabilizes with a finite radial extent…
International student mobility in Southern-Latin Europe: beyond the EU logics, towards a new space
2018
This paper discusses international student mobility (ISM) in Southern-Latin Europe, specifically Italy, Portugal, and Spain, analysing the inflow of international students as reflected in the UNESCO, OECD and European Commission databases. Only recently Italy, Portugal and Spain, as latecomers, have become more actively involved in ISM dynamics. This trend has been a response to EU pressures to internationalization, instrumented through the consolidation of the Bologna process and the need to build a common space of higher education. The analysis shows that at the intra-European level Italy, Portugal and Spain share similar ISM patterns; however, in the global context other logics shape ISM…