Experimental Study of a Dead-time Measurement Method Based on Time-interval Photon Statistics

Abstract

In this paper a dead-time measurement method consisting of measurement of the Fourier transform of the time-interval probability of a sinusoidal intensity is experimentally studied. It is found that dead time can be obtained with a small error for a wide variety of experimental conditions.     

Prosodic Cues Used During Perceptions of Nonunderstandings in Radio Communication

The readback/hearback protocol is a radio procedure intended to reduce communication errors in technical industries. It consists of the delivery of an instruction to a receiver, and the readback of that instruction by the receiver to confirm to the sender that it has been heard accurately. It does not, however, ensure that the receiver has understood the instruction. Using 2 samples within electricity transmission control, the present research explored whether the prosodic cues that listeners use to interpret uncertainty are also used to judge whether a receiver is perceived to have understood an instruction. Rising intonation and filled interturn delays were identified as prosodic cues that operators use to identify nonunderstandings. Theoretical and practical implications of the findings are considered.     

Radial Lip Seal Analysis—Finite Element Solution for a Body of Revolution

To deal with the complex geometry of radial lip seals, in particular the metal-to-rubber boundary and multiple lips, the elasticity equations for a body of revolution are an important step to improve the accuracy of the predicted solution. A nonlinear strain displacement finite element solution of the elasticity equations for a body of revolution is presented here. Following Zienkiewia. (1), the equations are derived from the work equivalence principle generalized to nonlinear problems. Realistic levels of Poisson's ratio present no difficulty when a technique of reduced integration is used (2), The elastic law is Hooke's law with thermal expansion.

External forces can be volume forces or surface forces. Both are converted into consistent nodal forces. Boundary conditions can be any combination of forces or displacements on any given node. This paper presents the equations and the solution by the finite element method as well as an extensive verification of the program prediction for thermal shrinkage of the seal from mold to ambient temperature, showing remarkable agreement with experiments in a large number of cases. Comparison of the prediction of the program for radial load and axial movement of the lip against experiment are also given, as well as comparison with the results of the previous code for conical shells.     

Effect of the curing régime on compressive strength

In a previous issue the Instituto Eduardo Torroja in Spain described the development of lightweight panels made from ordinary Portland cement and rice husk ash (RHA). This paper discusses the crucial effect of the curing régime on compressive strength with temperatures maintained at 30C and relative humidity at 80 percent.     

Resonant and non-resonant microwave absorption in the magnetoelectric YCrO3 through ferro-paraelectric transition

An electron paramagnetic resonance (EPR) study in the polycrystalline magnetoelectric YCrO₃ is carried out at X-band (8.8-9.8 GHz) in the 300-510 K temperature range. For all the temperatures, the EPR spectra show a single broad line attributable to Cr³⁺ (S = 3/2) ions. The onset of the ferro-paraelectric transition has been determined from the temperature dependence of three main parameters deduced from the EPR spectra: the peak-to-peak linewidth (ΔH_pp), the integrated intensity (I_EPR) and the g-factor; these parameters indicate a behavior in agreement with a diffuse phase transition. Low-field microwave absorption (LFMA) is used to give a further knowledge on this material; where this technique also gives evidence of the ferro-paraelectric transition.     

3D sound interactive environments for blind children problem solving skills

Audio-based virtual environments have been increasingly used to foster cognitive and learning skills. A number of studies have also highlighted that the use of technology can help learners to develop effective skills such as motivation and self-esteem. This study presents the design and usability of 3D interactive environments for children with visual disabilities to help them solve problems in Chilean geography and culture. We introduce AudioChile, a virtual environment that can be navigated through 3D sound to enhance spatiality and immersion throughout the environment. 3D sound is used to orientate, avoid obstacles, and identify the positions of various characters and objects within the environment. We have found during the usability evaluation that sound can be fundamental for attention and motivation purposes during interaction. Learners identified and clearly discriminated environmental sounds to solve everyday problems, spatial orientation, and laterality.     

Thick unevenness compensation in a hot rolling mill havingautomatic gage control

Hot rolling products with improved quality features such as thickness profile, strip width, flatness and material mechanical properties, are in increasing demand. The project goal is to improve the production quality in an existing hot rolling mill at Aceralia Steel Company, Aviles, Spain. This paper describes the design and implementation of a supervisory system for real-time compensation of uneven thickness on both sides of a rolled strip. The design is based on a multivariable process model, whose parameters are calculated online using measurement data from the mill. As a result, a computer system was developed that corrects the automatic gage control output from online acquired mill operation data. Previously, this task was done manually and periodically by a human operator. Manual correction is tedious and error prone, since it is based on visual inspection. Moreover, the proposed method leads to notorious improvement in the output strip quality, as the correcting signal may be continuously applied before the uneven thickness effect is visible     

Studies of chromaffin granule functioning by flow cytometry: transport of fluorescent epsilon-ATP and granular size increase induced by ATP

Flow cytometry techniques, usually employed to characterize cellular populations, are reported here to be a valuable tool to approach the study of subcellular organelle functioning. Chromaffin granules rendered fluorescent by using an antibody against their membrane protein, synaptophysin, are detectable by flow cytometry. Moreover, these storage granules are able to transport the fluorescent ATP analogue, epsilon-ATP (1,N6-ethenoadenosine 5'-triphosphate), and the resulting granular fluorescence increase can also be followed by this technique. The saturation studies show a non-hyperbolic kinetic behaviour, with a two step curve. The K0.5 values were 0.26 and 2.5 mM and Hill numbers 1 and 6 respectively. In addition, an unexpected granular size increase, which was dependent on the epsilon-ATP concentration, occurred together with the fluorescence increase. Other nucleotide triphosphate substrates of V-ATPase, such as ATP or GTP, but not the non-hydrolyzable analogue ATP gamma S (adenosine 5'-O-(3-thiotriphosphate), mimic this effect, which exhibited sigmoidal saturation curves with K0.5 values of 1.8 and 3.1 mM for ATP and epsilon-ATP respectively. The V-ATPase inhibitors, suramin, EGTA or EDTA significantly reduced the granular size increase in the presence of ATP. Extragranular addition of noradrenaline has no effect by itself on the granular size, but significantly reduced the granular size increase induced by ATP. This effect was reversed by the amine transport inhibitor reserpine. The granular size increase induced by ATP was more effective in the presence of Cl- than Br- or I-. Moreover, no increase occurred in the presence of F- or acetate. The Cl- channel blockers were poorly effective, and only 2-(phenylamino)-benzoic acid (DPC) exhibited an effect on the ATP-induced granular size increase.