Search results for "Shock"
showing 10 items of 1248 documents
Recensione di Graziano Mamone, Fabio Milazzo, Deserti della mente. Psichiatria e combattenti nella guerra di Libia 1911-1912, Milano, Le Monnier, 201…
2020
Review
Interest Rate Convergence, External Balances and the Euro Crisis
2016
Typically, the catching-up process between rich Northern Europe and poor Southern Europe and the diverging cost competitiveness between the two regions are considered alternative explanations for the widening current account imbalances in the euro area. This paper proposes a new explanation for the imbalances which led to the 2009 euro crisis i.e. large interest rate differentials among the EMU-12 countries which prevailed before the adoption of the euro. This finding suggests that the euro crisis was, at least to some extent, a consequence of the initial convergence shock.
The Speed of Exchange Rate Pass-Through
2016
On January 15, 2015, the Swiss National Bank terminated its minimum exchange rate policy of one euro against 1.2 Swiss francs. This policy shift resulted in a sharp, unanticipated and permanent appreciation of the Swiss franc by more than 11% against the euro. We analyze the exchange rate pass-through into import unit values of this shock at the daily frequency using Swiss transaction-level trade data. Our key findings are twofold. First, for goods invoiced in euro the pass-through is immediate and complete. This finding is consistent with no systematic nominal price adjustment in this subset of goods. Second, for goods invoiced in Swiss francs the pass-through is partial and very fast: it …
Short-Term Electricity Futures Prices: Evidence on the Time-Varying Risk Premium
2008
This paper examines empirically the relationship between electricity spot and futures prices, by analysing a decade of data for a set of short term-to-maturity futures contracts traded in the Nordic Power Exchange, Nord Pool. It is found that, on average, there are significant positive risk premiums in short-term electricity futures prices. The significance and size of the premiums, however, varies seasonally over the year; whereas it is greatest during winter, it is zero in summer. It is also found that time-varying risk premiums are significantly related to unexpectedly low reservoir levels. Furthermore, before the unprecedented supply-shock that hit the Nord Pool market around the end of…
Parameter tuning for nacelle-based passive structural control of a spar-type floating wind turbine
2013
This paper deals with the modeling and parameter tuning of a spar-type floating wind turbine with a tuned mass damper (TMD) installed in nacelle. Firstly, a mathematical model for the system surge-heave-pitch motion is established based on first principles. Secondly, different parameter tuning methods are adopted to find the optimal TMD parameters for load reduction. Thirdly, nonlinear wind turbine simulations with different designs are conducted under different wind and wave conditions. The results show that TMD with small spring and damping coefficients will help to produce much load reduction in above rated condition. However, it may deteriorate system performance when the turbine is wor…
Elements Design of the Equipment for the Closing of Shock Absorbers through the Rolling Method
2015
The objective of this paper is the design of some elements of equipment for the closing of shock absorbers through the rolling method with a wide range of tank tube lengths and also of the functional structure of the equipment with the shifting/settlement of the damper in the sertization process. Closing damper device is intended by the deflection of the upper reservoir tube. In the paper, the author present his concerns regarding the study and design (parts CAD, the crimping devices) of this equipment which use this proposed technology [1, 2] for the crimping rolling method for shock absorbers reservoir cylinders.
MODELING TORQUE TRANSMISSIBILITY FOR AUTOMOTIVE DRY CLUTCH ENGAGEMENT
2008
The dry clutch is a fundamental component in many automotive drivelines. For instance, the clutch torque transmissibility characteristic severely influences gearshift performance in automated manual transmissions. In this paper a novel model of the torque transmissibility of dry clutches is proposed. The dependence of the transmissibility characteristic on wear, slip speed and friction pads geometry and the influence of the diaphragm spring, the flat spring and the torsional damper springs is taken into account and pointed out. The sensitivity of a clutch engagement control scheme with respect to the clutch characteristic uncertainties is analyzed.
Shock formation in the dispersionless Kadomtsev-Petviashvili equation
2016
The dispersionless Kadomtsev-Petviashvili (dKP) equation $(u_t+uu_x)_x=u_{yy}$ is one of the simplest nonlinear wave equations describing two-dimensional shocks. To solve the dKP equation we use a coordinate transformation inspired by the method of characteristics for the one-dimensional Hopf equation $u_t+uu_x=0$. We show numerically that the solutions to the transformed equation do not develop shocks. This permits us to extend the dKP solution as the graph of a multivalued function beyond the critical time when the gradients blow up. This overturned solution is multivalued in a lip shape region in the $(x,y)$ plane, where the solution of the dKP equation exists in a weak sense only, and a…
Collisionless shock heating of heavy ions in SN 1987A
2019
Astrophysical shocks at all scales, from those in the heliosphere up to the cosmological shock waves, are typically "collisionless", because the thickness of their jump region is much shorter than the collisional mean free path. Across these jumps, electrons, protons, and ions are expected to be heated at different temperatures. Supernova remnants (SNRs) are ideal targets to study collisionless processes because of their bright post-shock emission and fast shocks. Although optical observations of Balmer-dominated shocks in young SNRs showed that the post-shock proton temperature is higher than the electron temperature, the actual dependence of the post-shock temperature on the particle mass…
XMM-Newton large programme on SN1006 - II. Thermal emission
2016
Based on the XMM-Newton large program on SN1006 and our newly developed spatially resolved spectroscopy tools (Paper~I), we study the thermal emission from ISM and ejecta of SN1006 by analyzing the spectra extracted from 583 tessellated regions dominated by thermal emission. With some key improvements in spectral analysis as compared to Paper~I, we obtain much better spectral fitting results with less residuals. The spatial distributions of the thermal and ionization states of the ISM and ejecta show different features, which are consistent with a scenario that the ISM (ejecta) is heated and ionized by the forward (reverse) shock propagating outward (inward). Different elements have differe…