386 research outputs found

    Strategies and measures aimed at consolidating public finances

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    The article outlines the current budgetary situation, explains why consolidation plans are urgently needed and provides an answer to the question as to what form those plans should preferably take. It also contains an insight into the strategies aimed at consolidating public finances. The financial crisis and the resultant economic recession have seriously undermined the health of public finances in almost all the developed economies. Budget deficits and public debt have risen sharply and these budgetary problems will not disappear automatically once the economy has fully recovered from the recession. On top of this, the budgetary impact of the ageing of the population could drive up budget deficits and cause public debt to rise even more quickly. To restore the sustainability of public finances, extensive consolidation efforts are required in a wide range of countries. Although a rapid and significant consolidation effort implemented simultaneously by a large group of countries could act as a brake on the economic recovery to some extent, a postponement of consolidation efforts, on the other hand, could shake the confidence of economic agents, give rise to financing risks and trigger a strong rise in interest rates. To remove doubts about the creditworthiness of countries, it is therefore advisable not to delay the announcement of concrete and credible austerity plans, even if the measures will only be implemented in the years to come. The timing and scope of consolidation efforts are dependent on country-specific circumstances. The scope of the consolidation efforts needed in most countries means that no limitations can be imposed with regard to the composition of consolidation plans. However, preference needs to be given to structural measures that reduce non-growth-promoting government expenditure or can dampen the increase in ageing-related expenditure. In spite of the already heavy burden of compulsory taxation in many countries, extra government revenues cannot be ruled out. Most countries have now begun preparing budgetary exit strategies. So there is some prospect of budgetary objectives that will herald a return to healthy public finances. In some countries, concrete austerity measures have already been worked out in the meantime. In other countries, plans of this type have yet to be detailed. However, firm government action is urgently required for this latter group of countries too, all the more so since postponing the necessary consolidation efforts would entail major risks.fiscal policy, budgetary consolidation, austerity plans, government debt

    Control Loop for a Pulse Generator of a Fast Septum Magnet using DSP and Fuzzy Logic

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    A prototype of a fast pulsed eddy current septum magnet for one of thebeam extraction's from the SPS towards LHC is under development. The precision of the magnetic field must be better than ±1.0 10-4 during a flat top of 30 µs. The current pulse is generated by discharging the capacitors of a LC circuit that resonates on the 1st and on the 3rd harmonic of a sine wave with a repetition rate of 15 s. The parameters of the circuit and the voltage on the capacitors must be carefully adjusted to meet the specifications. Drifts during operation must be corrected between two pulses by mechanically adjusting the inductance of the coil in the generator as well as the primary capacitor voltage. This adjustment process is automated by acquiring the current pulse waveform with sufficient time and amplitude resolution, calculating the corrections needed and applying these corrections to the hardware for the next pulse. A very cost-effective and practical solution for this adjustment process is the integration of off-the-shelf commercially available boards into an active digital control loop. A 16-bit fixed point, 33 MIPS, DSP together with a 12-bit, 500 kSPS, ADC (total cost of under 250 $) has been used for this control process. The correction algorithm developed for the DSP uses Fuzzy Logic reasoning

    Resonant Raman Scattering by quadrupolar vibrations of Ni-Ag Core-shell Nanoparticles

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    Low-frequency Raman scattering experiments have been performed on thin films consisting of nickel-silver composite nanoparticles embedded in alumina matrix. It is observed that the Raman scattering by the quadrupolar modes, strongly enhanced when the light excitation is resonant with the surface dipolar excitation, is mainly governed by the silver electron contribution to the plasmon excitation. The Raman results are in agreement with a core-shell structure of the nanoparticles, the silver shell being loosely bonded to the nickel core.Comment: 3 figures. To be published in Phys. Rev.

    High voltage measurements on a prototype PFN for the LHC injection kickers

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    Two LHC injection kicker magnet systems must produce a kick of 1.3 T.m each with a flattop duration of 4.25 mu s or 6.5 mu s, a rise time of 900 ns, and a fall time of 3 mu s. The ripple in the field must be less than +or-0.5The electrical circuit of the complete system has been simulated with PSpice. The model includes a 66 kV resonant charging power supply (RCPS), a 5 Omega pulse forming network (PFN), a terminated 5 Omega kicker magnet, and all known parasitic quantities. Component selection for the PEN was made on the basis of models in which a theoretical field ripple of less than +or-0.1as attained. A prototype 66 kV RCPS was built at TRIUMF and shipped to CERN. A prototype 5 Omega system including a PFN, thyratron switches, and terminating resistors, was built at CERN. The system (without a kicker magnet) was assembled as designed without trimming of any PFN component values. The PFN was charged to 60 kV via the RCPS operating at 0.1 Hz. The thyratron timing was adjusted to provide a 30 kV, 5.5 mu s duration pulse on a 5 Omega terminating resistor. Measurement data is presented for the prototype PFN, connected to resistive terminators. A procedure has been developed for compensating the probe and oscilloscope amplifier calibration errors. The top of the 30 kV pulse is flat to +or-0.3after an initial oscillation of 600 ns total duration. The post-pulse period is flat to within +or-0.1after approximately 600 ns from the bottom of the falling edge of the pulse. A calculation was performed in which a measured 27.5 kV pulse with a 5.5 mu s flattop was fed into a PSpice model of a kicker magnet with a 690 ns delay length. The resultant predicted kick rise time, from 0.2to 99.8, is 834 ns and the fall time 2.94 mu s, for a field pulse with a flattop of 4.69 mu s and a ripple of less than +or-0.2(12 refs)

    Design aspects related to the reliability of the LHC beam dump kicker systems

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    The two LHC beam dump kicker systems consist each of 14 pulse generator and magnet subsystems. Their task is to extract on request the beams in synchronisation with the gap in the beam. This operation must be fail-safe to avoid disastrous consequences due to loss of the beam inside the LHC. Only a failing operation of one of the 14 pulse generators is allowed. To preserve this tolerance premature beam dumps are forced immediately after early detection of internal faults. However, these faults should occur rarely in order not to be a source of undesirable downtime of the LHC. The report determines first the level of reliability required for the main components of the system. In particular faults which could cause spontaneously non-synchronised beam dumps are identified. Then, technical solutions are evaluated on failure behaviour. Those having a most likely failure mode which does not cause dump triggers are favoured. These solutions need redundancy and are more complex but have the advantage to be fault tolerant. The design goal can be achieved with a combination of high quality components, redundant signal paths, fault tolerant subsystems, continuous surveillance and check-list validation tests before the start of the injection of beam in the LHC

    Solid State Switch Application for the LHC Extraction Kicker Pulse Generator

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    A semiconductor solid state switch has been constructed and tested in the prototype extraction kicker pulse generator of CERN's Large Hadron Collider (LHC) [1]. The switch is made of 10 modified 4.5 kV, 66 mm symmetric GTO's (also called FHCT-Fast High Current Thyristor), connected in series. It holds off a d.c. voltage of 30 kV and conducts a 5 µs half-sine wave current of 20 kA with an initial di/dt of 10 kA/µs. Major advantages of the switch are the extremely low self-firing hazard, no power consumption during the ready-to-go status, instantaneous availability, simple condition control, very low noise emission during soft turn-on switching and easy maintenance. However, the inherent soft, relatively slow turn-on time is a non negligible part of the required rise time and this involves adaptation of generator components. A dynamic current range of 16 is achieved with variations in rise time, which stay within acceptable limits. Important generator improvements have been made with the series diodes and freewheel diodes. A more efficient droop compensation circuit is being studied. It is directly connected in series with the freewheel diode stack and maintains an acceptable flattop variation of 5% of the magnet current during 90 µs. This paper presents the complete generator, in particular the solid state switch and discusses related electrical measurements

    The Dutch Pregnancy Drug Register:Suitable to Study Paternal Drug Exposures?

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    Paternal medication use around the time of conception is common, but information about its effects on pregnancy outcome and the health of the child is generally limited. The aim of this study is to examine the feasibility of studying paternal exposure in the Dutch Pregnancy Drug Register by using immunosuppressants as a proof of concept. In 113 of 15,959 pregnancies, long-term paternal immunosuppressant use was reported 3 months before conception. In total, 134 immunosuppressants were used. Pregnancy outcome was known for 54 cases and was in accordance with previous findings. Two spontaneous abortions, two premature births, six small for gestational age babies, and two major congenital malformations were reported. Time to pregnancy (TTP) was known for 9548 pregnancies, including 89 with paternal immunosuppressant use. TTP analysis did not show a difference in pregnancies with paternal immunosuppressant use compared to the control group. Moreover, the number of fertility treatments in the paternal immunosuppressant group was similar to the control group. In our opinion, it is feasible to use the Dutch Pregnancy Drug Register to study the effects of paternal exposure on pregnancy outcome. However, to study the potential effects on fertility, more information is needed, particularly since the beginning of pregnancy attempts.</p

    The Dutch Pregnancy Drug Register:Suitable to Study Paternal Drug Exposures?

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    Paternal medication use around the time of conception is common, but information about its effects on pregnancy outcome and the health of the child is generally limited. The aim of this study is to examine the feasibility of studying paternal exposure in the Dutch Pregnancy Drug Register by using immunosuppressants as a proof of concept. In 113 of 15,959 pregnancies, long-term paternal immunosuppressant use was reported 3 months before conception. In total, 134 immunosuppressants were used. Pregnancy outcome was known for 54 cases and was in accordance with previous findings. Two spontaneous abortions, two premature births, six small for gestational age babies, and two major congenital malformations were reported. Time to pregnancy (TTP) was known for 9548 pregnancies, including 89 with paternal immunosuppressant use. TTP analysis did not show a difference in pregnancies with paternal immunosuppressant use compared to the control group. Moreover, the number of fertility treatments in the paternal immunosuppressant group was similar to the control group. In our opinion, it is feasible to use the Dutch Pregnancy Drug Register to study the effects of paternal exposure on pregnancy outcome. However, to study the potential effects on fertility, more information is needed, particularly since the beginning of pregnancy attempts.</p

    The Dutch Pregnancy Drug Register:Suitable to Study Paternal Drug Exposures?

    Get PDF
    Paternal medication use around the time of conception is common, but information about its effects on pregnancy outcome and the health of the child is generally limited. The aim of this study is to examine the feasibility of studying paternal exposure in the Dutch Pregnancy Drug Register by using immunosuppressants as a proof of concept. In 113 of 15,959 pregnancies, long-term paternal immunosuppressant use was reported 3 months before conception. In total, 134 immunosuppressants were used. Pregnancy outcome was known for 54 cases and was in accordance with previous findings. Two spontaneous abortions, two premature births, six small for gestational age babies, and two major congenital malformations were reported. Time to pregnancy (TTP) was known for 9548 pregnancies, including 89 with paternal immunosuppressant use. TTP analysis did not show a difference in pregnancies with paternal immunosuppressant use compared to the control group. Moreover, the number of fertility treatments in the paternal immunosuppressant group was similar to the control group. In our opinion, it is feasible to use the Dutch Pregnancy Drug Register to study the effects of paternal exposure on pregnancy outcome. However, to study the potential effects on fertility, more information is needed, particularly since the beginning of pregnancy attempts.</p
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