1,682 research outputs found
The excretion of biuret in the urine of sheep fed biuret
The articles have been scanned in colour with a HP scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentation PDF-Format
The pathological physiology of helminth infestation. lll. Trichostrongylus colubriformis
Trials are described in which the reactions of 11 sheep infested with T. colubriformis and 11 uninfected controls were studied in detail. The main findings in the acute disease were anorexia, retention of ingesta in the rumen and abomasum, diarrhoea, a severe hypo-albuminaemia and death 16 to 17 days after infestation. In the chronic disease there was a progressive decrease in feed intake and loss of body weight. Plasma albumin concentration decreased with a rise in plasma gamma globulin concentration later in the disease. A drop in packed red cell volume, haemoglobin concentration, red cell count, total volume of circulating erythrocytes and plasma inorganic phosphate was noted. There was a decrease in protein, phosphate and possibly selenium uptake leading to emaciation, muscular and myocardial atrophy and degeneration and eventually death.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Observability and nonlinear filtering
This paper develops a connection between the asymptotic stability of
nonlinear filters and a notion of observability. We consider a general class of
hidden Markov models in continuous time with compact signal state space, and
call such a model observable if no two initial measures of the signal process
give rise to the same law of the observation process. We demonstrate that
observability implies stability of the filter, i.e., the filtered estimates
become insensitive to the initial measure at large times. For the special case
where the signal is a finite-state Markov process and the observations are of
the white noise type, a complete (necessary and sufficient) characterization of
filter stability is obtained in terms of a slightly weaker detectability
condition. In addition to observability, the role of controllability in filter
stability is explored. Finally, the results are partially extended to
non-compact signal state spaces
Extracting Spatial Information from Noise Measurements of Multi-Spatial-Mode Quantum States
We show that it is possible to use the spatial quantum correlations present
in twin beams to extract information about the shape of a mask in the path of
one of the beams. The scheme, based on noise measurements through homodyne
detection, is useful in the regime where the number of photons is low enough
that direct detection with a photodiode is difficult but high enough that
photon counting is not an option. We find that under some conditions the use of
quantum states of light leads to an enhancement of the sensitivity in the
estimation of the shape of the mask over what can be achieved with a classical
state with equivalent properties (mean photon flux and noise properties). In
addition, we show that the level of enhancement that is obtained is a result of
the quantum correlations and cannot be explained with only classical
correlations
The impact of deep-sea fisheries and implementation of the UNGA Resolutions 61/105 and 64/72. Report of an international scientific workshop
The scientific workshop to review fisheries management, held in Lisbon in May 2011, brought together 22 scientists and fisheries experts from around the world to consider the United Nations General Assembly (UNGA) resolutions on high seas bottom fisheries: what progress has been made and what the outstanding issues are. This report summarises the workshop conclusions, identifying examples of good practice and making recommendations in areas where it was agreed that the current management measures fall short of their target
Theory of Two-Dimensional Josephson Arrays in a Resonant Cavity
We consider the dynamics of a two-dimensional array of underdamped Josephson
junctions placed in a single-mode resonant cavity. Starting from a well-defined
model Hamiltonian, which includes the effects of driving current and
dissipative coupling to a heat bath, we write down the Heisenberg equations of
motion for the variables of the Josephson junction and the cavity mode,
extending our previous one-dimensional model. In the limit of large numbers of
photons, these equations can be expressed as coupled differential equations and
can be solved numerically. The numerical results show many features similar to
experiment. These include (i) self-induced resonant steps (SIRS's) at voltages
V = (n hbar Omega)/(2e), where Omega is the cavity frequency, and n is
generally an integer; (ii) a threshold number N_c of active rows of junctions
above which the array is coherent; and (iii) a time-averaged cavity energy
which is quadratic in the number of active junctions, when the array is above
threshold. Some differences between the observed and calculated threshold
behavior are also observed in the simulations and discussed. In two dimensions,
we find a conspicuous polarization effect: if the cavity mode is polarized
perpendicular to the direction of current injection in a square array, it does
not couple to the array and there is no power radiated into the cavity. We
speculate that the perpendicular polarization would couple to the array, in the
presence of magnetic-field-induced frustration. Finally, when the array is
biased on a SIRS, then, for given junction parameters, the power radiated into
the array is found to vary as the square of the number of active junctions,
consistent with expectations for a coherent radiation.Comment: 11 pages, 8 eps figures, submitted to Phys. Rev
Magnetically geared pseudo direct drive for safety critical applications
The paper presents an investigation into the electromagnetic design and performance of a fault-tolerant magnetically geared Pseudo Direct Drive (PDD®) electrical machine for primary flight control surface electromechanical actuation. It is shown that a large number of combinations of high-speed rotor (HSR) pole pairs, pole-piece numbers, and stator slot numbers exist for which a duplex 3-phase fault tolerant configuration can be realized. Furthermore, in addition to facilitating a lower mass solution, it is also shown that a PDD presents a significantly lower inertia referred to the screw, when compared to direct-drive or mechanically geared motor solutions. The findings are validated on a prototype PDD, which has been designed and built to meet the requirements of primary control surface electromechanical actuator
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