1,678 research outputs found
Memories of Empire in Cold War Japan
Between 1895 and 1945 Japan assembled one of the largest empires in modern
world history. It vanished abruptly in the summer of 1945 at the end of the
Second World War, and seemed to leave no trace in public consciousness.
Historians, too, have portrayed postwar Japan as characterized by a virtual
erasure of the imperial past. This article draws on recent scholarship to
argue that things were more complicated than that. While references to the
imperial past indeed dwindled after about 1960, immediate forgetting did not
exhaust the reactions by individuals and interest groups. Some social milieus
experienced the dissolution of the empire much more profoundly than official
discourse would suggest. Since the mid-1990s, Japan's imperial past has
reemerged as a major field of historical inquiry and a more general concern in
public debate. In this article I situate the dialectic of remembering and
forgetting within larger processes and transformations of the postwar order in
East Asia, in particular the American occupation and the emergence of the Cold
War
Die Politik der nationalen ,Abschließung'.: Die Überwindung des ,westlichen Geschichtsbildes' in Japan?
Peter Feldbauer / Jean Paul Lehners / Bernd Hausberger (Hrsg.): Globalgeschichte. Die Welt 1000–2000, 8 Bde, Wien:: Mandelbaum Verlag 2008–2011, 2902 S.
Determining Dark Matter properties with a XENONnT/LZ signal and LHC-Run3 mono-jet searches
We develop a method to forecast the outcome of the LHC Run 3 based on the
hypothetical detection of signal events at XENONnT. Our
method relies on a systematic classification of renormalisable single-mediator
models for dark matter-quark interactions, and is valid for dark matter
candidates of spin less than or equal to one. Applying our method to simulated
data, we find that at the end of the LHC Run 3 only two mutually exclusive
scenarios would be compatible with the detection of signal
events at XENONnT. In a first scenario, the energy distribution of the signal
events is featureless, as for canonical spin-independent interactions. In this
case, if a mono-jet signal is detected at the LHC, dark matter must have spin
1/2 and interact with nucleons through a unique velocity-dependent operator. If
a mono-jet signal is not detected, dark matter interacts with nucleons through
canonical spin-independent interactions. In a second scenario, the spectral
distribution of the signal events exhibits a bump at non zero recoil energies.
In this second case, a mono-jet signal can be detected at the LHC Run 3, dark
matter must have spin 1/2 and interact with nucleons through a unique
momentum-dependent operator. We therefore conclude that the observation of
signal events at XENONnT combined with the detection, or the
lack of detection, of a mono-jet signal at the LHC Run 3 would significantly
narrow the range of possible dark matter-nucleon interactions. As we argued
above, it can also provide key information on the dark matter particle spin.Comment: 17 pages, 8 figures, updated operator coefficients and figures,
version accepted by PR
Perspectivas en Diálogo
En su nueva edición de 2021, Perspectivas en Diálogo ofrece a sus lectores
un nuevo debate enfocado en la Historia Global como perspectiva de análisis
histórico. En este caso, Juan Pablo Scarfi y Eduardo Zimmermann dialogan
con Sebastian Conrad sobre su libro What Is Global History
Flashboiling atomization in nozzles for GDI engines
[EN] Flashboiling denotes the phenomenon of rapid evaporation and atomization at nozzles, which occurs when fluids
are injected into ambient pressure below their own vapor pressure. It happens in gasoline direct injection (GDI)
engines at low loads, when the cylinder pressure is low during injection due to the closed throttle valve. The fuel
temperature at the same time approaches cylinder head coolant temperature due to the longer dwell time of the
fuel inside the injector. Flash boiling is mainly beneficial for atomization quality, since it produces small droplet
sizes and relative broad and homogenous droplet distributions within the spray. Coherently, the penetration depth
normally decreases due to the increased aerodynamic drag. Therefore the thermal properties of injectors are
often designed to reach flash boiling conditions as early as possible. At the same time, flash boiling significantly
increases the risk of undesired spray collapsing. In this case, neighbouring jets converge and form a single jet.
Due to the now concentrated mass, penetration depth is enhanced again and can lead to liner or piston wetting in
addition to the overall diminished mixture formation.
In order to understand the underlying physics, it is important to study the occurring phenomena flashboiling and
jet-to-jet interacting i.e. spray collapsing separately. To this end, single hole injectors are built up to allow for an
isolated investigation of flashboiling. The rapid expansion at the nozzle outlet is visualized with a microscopic high
speed setup and the forces that lead to the characteristic spray expansion are discussed. Moreover, the results
on the macroscopic spray in terms of penetration, cone angles and vapor phase are shown with a high speed
Schlieren setup. Resulting droplet diameters and velocities are measured using LDA/PDA.
As a result, we find a comprehensive picture of flash boiling. The underlying physics can be described and
discussed for the specific case of high pressure injection at engine relevant nozzle geometries and conditions, but
independently from neighbouring jets. These findings provide the basis to understand and investigate flashboiling
and jet-to-jet interaction as distinct, but interacting subjects rather than a combined phenomenon.The authors would like to thank Continental for providing the experimental injectors used in this paper and
Specialised Imaging for providing parts of the equipment used for the shown measurements.
Additionally the authors gratefully acknowledge the financial support for parts of their work from the Erlangen
Graduate School in Advanced Optical Technologies (SAOT) within the framework of the German Excellence
Initiative by the German Research Foundation (DFG).Bornschlegel, S.; Conrad, C.; Eichhorn, L.; Wensing, M. (2017). Flashboiling atomization in nozzles for GDI engines. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 321-328. https://doi.org/10.4995/ILASS2017.2017.4750OCS32132
Finanzmarkt: Regulierung auf dem richtigen Weg?
Fünf Jahre nach dem Ausbruch der Finanzmarktkrise hat sich einiges getan: Die USA und die Mitgliedstaaten der Europäischen Union haben verschiedene Regulierungen auf den Weg gebracht. Die Autoren beurteilen dies allerdings unterschiedlich. Zum einen seien die Regulierungen nicht ausreichend und nicht zielgenau, zum anderen sind Unklarheiten und eine Vermengung von Kompetenzen entstanden. Zudem stellt sich die Frage, ob eine striktere Finanzmarktregulierung den Kern des Problems trifft.Immediately after the financial market crisis of 2008/2009 many politicians and economists insisted on a stricter regulation of financial markets. Since then the governments in the USA and the EU have signifi cantly tightened financial market regulation and oversight. But there are conceptual and technical problems with the latest Basel III proposals as well as with the institutional design of banking supervison. Not only rules for banking operations, but also credit rating agencies, accounting standards and the organisational structure of banks should be considered on the way to sound fi nancial markets. However, the new legislation will not succeed in making the global financial system crisis-proof as a number of problems such as global imbalances, excessive complexity in the financial sector and inherent instability of asset prices have not been addressed. There is no consensus among the authors on the ability and willingness of politicians to achieve better regulated financial markets
Innovative Dam Monitoring Tools Based on Distributed Temperature Measurement
Distributed fibreoptic measurements contain a number of particular features. Even though they are nowadays used for strain measurements, actually the most interesting parameter to be monitored by distributed fibreoptic measurements in dams is temperature. Due to their enormous mass, large structures such as dams usually show very slow behaviour in terms of temperature changes. It is well known that temperature measurements have to be carried out in concrete dams in order to observe the development of the heat of hydration. Furthermore, seepage flows affect the temperature field within the dams and their foundations. The Distributed Fibre Optic Temperature DFOT measurement was identified to be ideally suited for monitoring the temperature fields of dams, both for leakage detection and for the observation of concrete temperatures. For almost one decade, DFOT measurement has proven to be a powerful tool to detect and locate leakage in hydraulic structures. Leakage detection by means of DFOT measurements has been typically implemented through two major approaches: the gradient method, which employs the temperature as a tracer to detect anomalies in the flow field; and the heat-up method, which allows detecting the presence and movement of water by evaluating the thermal response after external heat is induced. In the past years more and more DFOT projects are under progress. As for today, the DFOT measurement has to be considered as a state of the art tool in dam monitoring. Nevertheless, especially in the field of leakage detection, there is still an enormous potential to improve effectiveness. New additional applications will be developed and important parameters as the seepage velocity in soil material will be measured with DFOT technology in the future. Being robust and gaining a high density of in-situ information out of the dam, DFOT technology has to be considered as one of the key technologies in tomorrow’s dam monitoring
-factors for self-interacting dark matter in 20 dwarf spheroidal galaxies
Dwarf spheroidal galaxies are among the most promising targets for indirect
dark matter (DM) searches in -rays. The -ray flux from DM
annihilation in a dwarf spheroidal galaxy is proportional to the -factor of
the source. The -factor of a dwarf spheroidal galaxy is the line-of-sight
integral of the DM mass density squared times , where is the DM annihilation cross-section times relative velocity , angle brackets denote average over , and is the -independent
part of . If is
constant in , -factors only depend on the DM space distribution
in the source. However, if varies with , as in the presence of DM self-interactions, -factors also depend on
the DM velocity distribution, and on the strength and range of the DM
self-interaction. Models for self-interacting DM are increasingly important in
the study of the small scale clustering of DM, and are compatible with current
cosmological observations. Here we derive the -factor of 20 dwarf spheroidal
galaxies from stellar kinematic data under the assumption of Yukawa DM
self-interactions. -factors are derived through a profile Likelihood
approach, assuming either NFW or cored DM profiles. We also compare our results
with -factors derived assuming the same velocity for all DM particles in the
target galaxy. We find that this common approximation overestimates the
-factors by up to one order of magnitude. -factors for a sample of DM
particle masses, self-interaction coupling constants and density profiles are
provided electronically, ready to be used in other projects.Comment: 10 pages, 3 figures and 2 table
- …