2,940 research outputs found
Radiation and magnetic field effects on new semiconductor power devices for HL-LHC experiments
The radiation hardness of commercial Silicon Carbide and Gallium Nitride
power MOSFETs is presented in this paper, for Total Ionizing Dose effects and
Single Event Effects, under gamma, neutrons, protons and heavy ions. Similar
tests are discussed for commercial DC-DC converters, also tested in operation
under magnetic field
Weather variability and food consumption
This study examines the impact of weather variations on food consumption in rural Uganda. The paper relies on two-period panel data (2005/06-2009/10) combined with data on rainfall, number of rainy days and maximum and minimum temperatures. We find that higher temperatures have an adverse effect on food consumption. In contrast, food consumption is not substantially affected by rainfall variations. While evidence from qualitative interviews and trends in agricultural production suggest that households are adopting mitigation measures, the conclusion from the evidence assembled in this paper is that higher temperatures are associated with a decline in crop yields and food consumption
Macroeconomics of natural disasters
We use the case of the
impact of natural disasters to analyse
strengths and weaknesses of meta-analysis in an emerging research field.
Macroeconomists have published on this issue since 2002 (we identified 22
studies to date). The results of the studies are contradictory and therefore the
need to synthesize the available research is evident. Meta-analysis is a useful
method in this field. First, we observe many methodological differences in
terms of heterogeneity in the data sources, the samples (country coverage and
research period), the econometric specifications and the estimation procedures.
We use meta-analysis both to identify the extent of heterogeneity and its
potential impact and to find out research needs. Second, in this emerging
scientific field the findings are preliminary and often contradictory due to the
scientific process of finding out the ‘true’ effect. Meta-analysis can be used to
distil this effect that often cannot be observed on the basis of individual
studies. Third, as meta-analysis provides a transparent and objective way to
synthesize research, this tool is useful in an area that like natural disasters
impact is vulnerable to bias due to the ideological or intrinsic motivation of the
researcher.
An
aim of our paper is to show how one can use the identified
methodological characteristics to better understand the significance of future
findings. Understanding the robustness and importance of new findings is
crucial because they influence policy decisions with a potentially long-run
impact, especially since both prevention and mitigation require investments
over considerable periods of time. The second aim is to find out what are the
most important research needs from the perspective of the emerging literature.
We identify strengths and weaknesses in terms of coverage and robustness of
control variables showing gaps in the literature and highlighting the importance
of some rigour in the phase of reporting results and, for example, suggest that
it is necessary to include population and institutions more often among the
control variables.
We also provide a
study on the IPCC’s special report Managing the
Risks of Extreme Events and Disasters to Advance Climate Change Adaptation in order
to contrast the meta-analysis and its findings with an influential traditional
review of literature (that also comprises qualitative research).
The two
methods
force two different perspectives on researchers and each
perspective helps to uncover other (aspects of) literatures. Our conclusion is
that research synthesis would benefit from combining the two approaches. A
meta-analysis without a traditional review of the literature is incomplete
Natural disasters impact, factors of resilience and development: A meta-analysis of the macroeconomic literature
We systematize recent macroeconomic empirical literature on the direct and indirect impact of natural disasters providing a meta-analysis of 20 studies published during 2002-2013. We show that the disagreement between these studies is caused by the empirical design, the estimation technique and the resilience factors included in the analyses. The meta-regression suggests that studies that analyse indirect costs have a 88% higher probability to find a positive significant disaster impact than studies of direct costs. If the impact of the disaster is modelled through a disaster indicator, the likelihood of finding a negative and significant disaster impact increases by 64%
High B test of a commercial step-down Point of Load for LHC experiments
The performance in magnetic field (B-field) of the commercial DC-DC converter LTM8033, from Linear Technology, has been evaluated. The tests have been carried out at the Laboratorio Acceleratori e Superconduttivit\ue0 Applicata (LASA), in Milan (Italy), on December 2013 and the experimental results are here presented and discussed. Their ability to operate in hostile environment is particularly interesting for physics experiments where the presence of radiation and strong B field make electronic devices challenged to function . In particular, in this article the operation in high B-field environment will be investigated and discussed
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