Delocalization power of global unitary operations on quantum information

We investigate how originally localized two pieces of quantum information represented by a tensor product of two unknown qudit states are delocalized by performing two-qudit global unitary operations. To characterize the delocalization power of global unitary operations on quantum information, we analyze the necessary and sufficient condition to deterministically relocalize one of the two pieces of quantum information to its original Hilbert space by using only LOCC. We prove that this LOCC one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent to a controlled-unitary operation. The delocalization power and the entangling power characterize different non-local properties of global unitary operations.Comment: 14 pages, 1 figur

Spacetime could be simultaneously continuous and discrete in the same way that information can

There are competing schools of thought about the question of whether spacetime is fundamentally either continuous or discrete. Here, we consider the possibility that spacetime could be simultaneously continuous and discrete, in the same mathematical way that information can be simultaneously continuous and discrete. The equivalence of continuous and discrete information, which is of key importance in information theory, is established by Shannon sampling theory: of any bandlimited signal it suffices to record discrete samples to be able to perfectly reconstruct it everywhere, if the samples are taken at a rate of at least twice the bandlimit. It is known that physical fields on generic curved spaces obey a sampling theorem if they possess an ultraviolet cutoff. Most recently, methods of spectral geometry have been employed to show that also the very shape of a curved space (i.e., of a Riemannian manifold) can be discretely sampled and then reconstructed up to the cutoff scale. Here, we develop these results further, and we here also consider the generalization to curved spacetimes, i.e., to Lorentzian manifolds

Advanced ceramic coating development for industrial/utility gas turbine applications

The effects of ceramic coatings on the lifetimes of metal turbine components and on the performance of a utility turbine, as well as of the turbine operational cycle on the ceramic coatings were determined. When operating the turbine under conditions of constant cooling flow, the first row blades run 55K cooler, and as a result, have 10 times the creep rupture life, 10 times the low cycle fatigue life and twice the corrosion life with only slight decreases in both specific power and efficiency. When operating the turbine at constant metal temperature and reduced cooling flow, both specific power and efficiency increases, with no change in component lifetime. The most severe thermal transient of the turbine causes the coating bond stresses to approach 60% of the bond strengths. Ceramic coating failures was studied. Analytic models based on fracture mechanics theories, combined with measured properties quantitatively assessed both single and multiple thermal cycle failures which allowed the prediction of coating lifetime. Qualitative models for corrosion failures are also presented

A canine model of irreversible urethral sphincter insufficiency

OBJECTIVE To develop a canine model of external urinary sphincter insufficiency by creating irreversible damage to the sphincter, because there is a need for a reliable and reproducible large animal model for the study of stress urinary incontinence (SUI) caused by deficient sphincter function. MATERIALS AND METHODS About a quarter of the total external sphincter muscle was removed microsurgically from seven female dogs; three age-matched dogs served as normal controls. The dogs had standard urodynamic and radiographic studies before and at 1, 2, 3, 4 and 7 months after surgery. Three dogs were killed at 4 months and four at 7 months after surgery for tissue analyses. RESULTS The interventions produced a consistent outcome. Urodynamic studies showed a significant and sustained decrease in sphincter function, which included a static urethral pressure profile, stress urethral profile and detrusor leak-point pressure. Furthermore, in vivo pudendal nerve stimulation and organ-bath studies of the retrieved tissue strips confirmed the loss of sphincter tissue function. Histologically, absence of functional sphincter muscle was evident in the damaged sphincter region. CONCLUSIONS These results show that a reliable and reproducible canine model of irreversible sphincter insufficiency can be created by microsurgical removal of sphincter muscle tissue. This model of external sphincter insufficiency could be used for evaluating methods (e.g. cell therapies) for treating SUI

Ultimate pH values in reindeer meat with particular regard to animal sex and age, muscle and transport distance

The distribution of ultimate pH values and the frequency of high pH values in three reindeer muscles (AL longissimus, M. biceps femoris and M. triceps brachii) from bulls, cows and calves after short and long distance transport were studied. About 3400 reindeer carcasses from 12 different herds were included in this study. The post mortem processes in reindeer meat seemed to develop very rapidly, and therefore an early measurement (approx. 15h post mortem) of ultimate pH can be done without electrical stimulation of the carcasses. In a comparison between muscles, M. triceps brachii had a higher ultimate pH value than M. longissimus and M. biceps femoris. Meat from reindeer calves had higher ultimate pH values than meat from adult animals, indicating that calves are more susceptible to stress than adult animals and hence deplete their energy stores more readily. Road transport by lorry did not cause any increase in ultimate pH values in bulls and calves. Reindeer cows, however, did have an increase in ultimate pH, while more borderline cases of DFD (5.80<pH<6.20) were observed when cows were transported over more than 500 km. The physical condition and energy balance of the animals before transport were suggested to determine their ability to tolerate transport stress

Unambiguous comparison of the states of multiple quantum systems

We consider N quantum systems initially prepared in pure states and address the problem of unambiguously comparing them. One may ask whether or not all $N$ systems are in the same state. Alternatively, one may ask whether or not the states of all N systems are different. We investigate the possibility of unambiguously obtaining this kind of information. It is found that some unambiguous comparison tasks are possible only when certain linear independence conditions are satisfied. We also obtain measurement strategies for certain comparison tasks which are optimal under a broad range of circumstances, in particular when the states are completely unknown. Such strategies, which we call universal comparison strategies, are found to have intriguing connections with the problem of quantifying the distinguishability of a set of quantum states and also with unresolved conjectures in linear algebra. We finally investigate a potential generalisation of unambiguous state comparison, which we term unambiguous overlap filtering.Comment: 20 pages, no figure

The influence of DACCIWA radiosonde data on the quality of ECMWF analyses and forecasts over southern West Africa

During the DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) field campaign ∼900 radiosondes were launched from 12 stations in southern West Africa from 15 June to 31 July 2016. Subsequently, data-denial experiments were conducted using the Integrated Forecasting System of the European Centre for Medium-range Weather Forecasts (ECMWF) to assess the radiosondes\u27 impact on the quality of analyses and forecasts. As observational reference, satellite-based estimates of rainfall and outgoing long-wave radiation (OLR) as well as the radiosonde measurements themselves are used. With regard to the analyses, the additional observations show positive impacts onwinds throughout the troposphere and lower stratosphere, while large lower-tropospheric cold and dry biases are hardly reduced. Nonetheless, downstream, that is farther inland from the radiosonde stations,we find a significant increase (decrease) in low-level night-time temperatures (monsoon winds) when incorporating the DACCIWA observations, suggesting a possible linkage via weaker cold air advection fromthe Gulf of Guinea. The associated lower relative humidity leads to reduced cloud cover in the DACCIWA analysis. Closer to the coast and over Benin and Togo, DACCIWA observations increase low-level specific humidity and precipitable water, possibly due to changes in advection and vertical mixing. During daytime, differences between the two analyses are generally smaller at low levels. With regard to the forecasts, the impact of the additional observations is lost after a day or less. Moderate improvements occur in low-level wind and temperature but also in rainfall over the downstream Sahel, while impacts on OLR are ambiguous. The changes in precipitation appear to also affect high-level cloud cover and the tropical easterly jet. The overall rather small observation impact suggests that model and data assimilation deficits are the main limiting factors for better forecasts inWest Africa. The new observations and physical understanding from DACCIWA can hopefully contribute to reducing these issues

Collision Dynamics and Solvation of Water Molecules in a Liquid Methanol Film

Environmental molecular beam experiments are used to examine water interactions with liquid methanol films at temperatures from 170 K to 190 K. We find that water molecules with 0.32 eV incident kinetic energy are efficiently trapped by the liquid methanol. The scattering process is characterized by an efficient loss of energy to surface modes with a minor component of the incident beam that is inelastically scattered. Thermal desorption of water molecules has a well characterized Arrhenius form with an activation energy of 0.47{\pm}0.11 eV and pre-exponential factor of 4.6 {\times} 10^(15{\pm}3) s^(-1). We also observe a temperature dependent incorporation of incident water into the methanol layer. The implication for fundamental studies and environmental applications is that even an alcohol as simple as methanol can exhibit complex and temperature dependent surfactant behavior.Comment: 8 pages, 5 figure

Quasinormal Modes, the Area Spectrum, and Black Hole Entropy

The results of canonical quantum gravity concerning geometric operators and black hole entropy are beset by an ambiguity labelled by the Immirzi parameter. We use a result from classical gravity concerning the quasinormal mode spectrum of a black hole to fix this parameter in a new way. As a result we arrive at the Bekenstein - Hawking expression of $A/4 l_P^2$ for the entropy of a black hole and in addition see an indication that the appropriate gauge group of quantum gravity is SO(3) and not its covering group SU(2).Comment: 4 pages, 2 figure

Stochastic backgrounds of gravitational waves from extragalactic sources

Astrophysical sources emit gravitational waves in a large variety of processes occurred since the beginning of star and galaxy formation. These waves permeate our high redshift Universe, and form a background which is the result of the superposition of different components, each associated to a specific astrophysical process. Each component has different spectral properties and features that it is important to investigate in view of a possible, future detection. In this contribution, we will review recent theoretical predictions for backgrounds produced by extragalactic sources and discuss their detectability with current and future gravitational wave observatories.Comment: 10 pages, 9 figures, proceedings of the GWDAW 10 Conference, submitted to Class. & Quantum Gra