1,488 research outputs found
Thermal Quench at Finite t'Hooft Coupling
Using holography we have studied thermal electric field quench for infinite
and finite t'Hooft coupling constant. The set-up we consider here is D7-brane
embedded in ( corrected) AdS-black hole background. It is well-known
that due to a time-dependent electric field on the probe brane, a
time-dependent current will be produced and it will finally relax to its
equilibrium value. We have studied the effect of different parameters of the
system on equilibration time. As the most important results, we have observed a
universal behaviour in the rescaled equilibration time in the very fast quench
regime for different values of the temperature and correction
parameter. It seems that in the slow quench regime the system behaves
adiabatically. We have also observed that the equilibration time decreases in
finite t'Hooft coupling limit.Comment: 6 pages, 9 figure
Probe Branes Thermalization in External Electric and Magnetic Fields
We study thermalization on rotating probe branes in AdS_5 x S^5 background in
the presence of constant external electric and magnetic fields. In the AdS/CFT
framework this corresponds to thermalization in the flavour sector in field
theory. The horizon appears on the worldvolume of the probe brane due to its
rotation in one of the sphere directions. For both electric and magnetic fields
the behaviour of the temperature is independent of the probe brane dimension.
We also study the open string metric and the fluctuations of the probe brane in
such a set-up. We show that the temperatures obtained from open string metric
and observed by the fluctuations are larger than the one calculated from the
induced metric.Comment: 27 pages, 7 figure
Development of Serial Crystallography Methods for Synchrotrons and X-ray Free-Electron Lasers
X-ray crystallography of proteins is a well-established method to identify atomic level molecular arrangement, however when exposing crystalline proteins to ionising radiation, damage can occur to their overall molecular structure (global damage), while solvated electrons generated by X-rays can induce changes to metal sites within a protein (site-specific damage) (Garman & Weik, 2015). These changes occur quickly, at doses much lower than required to obtain a complete dataset, meaning there may be many metalloproteins deposited in the Protein Data Bank that are incorrect (Bowman, Bridwell-Rabb, & Drennan, 2016).
The advent of X-ray free-electron lasers (XFELs) that produce femtosecond pulses of extremely high quality (brilliance) X-ray beams, allows data to be collected before radiation damage has the time to occur (Schlichting, 2015). This thesis will describe the development of novel ‘chip’ based serial data collection and processing strategies, applied at Diamond Light Source microfocus beamline I24, and at BL3 EH2 at the SACLA XFEL, Japan. A technique coined ‘multiple serial structures’ (MSS) has been developed and used in this thesis to assess how crystalline proteins change as a function of X-ray dose, as enzyme reactivity can be driven in crystals by exploiting X- ray generated solvated electrons to drive redox reactions (Horrell et al., 2016). By performing a near identical data collection strategy at the SACLA XFEL, we have been able to directly compare the effects of accumulated dose in MSS datasets to ‘damage free’ XFEL structures, using the same target protein. Chip methods have also been examined and developed in this thesis as a tool to assess the ‘dark progression’ of radiation damage, a technique we have coined ‘dark progression series’ (DPS). Further, we present a data processing technique that possesses the ability to identify protein-ligand complexes from extremely small subsets of synchrotron and XFEL diffraction data, whereby only a few hundred diffraction images may be needed
Biostratigraphic Study of the Gurpi Formation Based on Planktonic Foraminifera In Lar Area (Kuh-e-kurdeh Section)
The study of planktonic foraminifera of the Gurpi formations at Lar area (Kuh-e-kurdeh section) enables me to find the most standard biozones defined in mediterranean regions, especially Tethysian domain. Five biozones were determined. Biozones I (Globotruncanita elevata zone) and II (Globotruncana ventricosa zone) and III (Radotruncana calcarata zone) indicate the Early Campanian and Middle and Late Campanian, respectively. Biozones IV (Globotruncanita stuarti zone) and V (Gansserina gansseri zone) suggest the Early and Middle Maastrichtian, respectively. In the Late Maastrichtian, due to decreasing in water depth at the study area, Abathomphalus mayaroensis zone defined in Tethysian domain was not recognised.


Modeling of a Contact-Less Electric-Vehicle Battery-Charging Station Fed from On-Grid Photovoltic Arrays
Electric vehicles (EVs) are environmental friendly due to no exhaust gases or carbon dioxide. In addition, there is no noise through operation. However, up to now, there are some challenges that facing its spread through all over the world. The main problem that these vehicles face is the fast charging process of the used batteries through neat and clean source without plugs. So, this chapter deals with a proposed method for a contactless battery charger of both electric and hybrid electric vehicles (HEVs) from renewable resources. The chapter proposes a public station for fast charging. This station implies off-board battery charger fed from on-grid (OG) photovoltaic (PV) arrays through inductively power transfer (IPT). This comfortable 100Â kW contactless power station is designed, modeled, and simulated as a general software package reliable to be used for any other station design. The air gap of the air-core transformer (ACT) divides the station into two parts. The first part implies roof-mounted PV array with its intelligent-controlled maximum power point tracking (MPPT) technique, power converter, three-level power inverter, and resonant compensator converter that operates at high frequency. The second one includes rectifiers and switched mode power converter with smart controller. The chapter includes samples for simulation results that are obtained from the Matlab software package
Research, Development, Production and Performance of heavy duty CNG fleets in Iran
In recent years, along with the trend toward clean air and less dependency to imported oil products, there has been increasing willing to use substitute fuels in transport industry. Automobile industry is an exhaustive industry bringing development for any country. The industrial capabilities needed for development rest in this branch of industry. The Iranian automobile making companies move in line with this aim. But in recent decades, in addition to development of automobile industry, the pollution too has occupied the minds of the authorities of these companies. Some measures, investments, researches, and exhaustive studies related to the pollution problem have been made to produce an automobile of higher technology and lower pollution.Natural gas,Substitutes fuels
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