Response time/temporal

Photodiodes occur in many different varieties and are useful in both steady-state and time-resolved fluorescence studies. Photodiodes designed for use in steady-state or on microsecond time-scales are inexpensive and have effective areas up to a few square millimeters, and are capable of efficiently matching to simple focusing optics. However, as the temporal resolution increases so does the cost, and the effective area has to be reduced. For example, APDs with response times in the 50 psec region have effective diameters ofca. 10 /small active area of high-speed devices is currently the primary drawback in fluorescence studies. Also, photodiodes other... 

Nicotine modulated alertness-brain related activity in several brain regions, but did not significantly influence response times. In the visual condition, nicotine decreased alertness-brain activity in the right lateral posterior superior temporal gyrus. In the auditory modality, effects of nicotine were trial-specific decreased activation in frontal and occipitoparietal regions in warned trials and increased activation in unwarned trials. 

In the typical setup, excitation light is provided by a pulsed (e.g., nanosecond) laser (emitting in the visible range, e.g., at 532 nm, if Mb is investigated), while the probe is delivered by a continuous-wave (cw) laser. The two beams are spatially overlapped in the sample, and the temporal changes in the optical properties (such as optical absorption or frequency shift) that follow the passage of the pump pulse are registered by a detector with short response time (relative to time scale of the processes monitored), such as a fast photodiode. 

In some instances, the design of the data acquisition system may be driven by the requirements of a specific application. In ICP-MS, for example, the masses of the elemental isotopes are well known, so only those masses need to be investigated. In such a situation, an attractive technique is the use of a number of single-channel devices, such as boxcar integrators [38], each of which is responsible for continually monitoring a specific mass of interest. At the expense of complete mass spectral coverage, a simple, inexpensive system that generates relatively small amounts of data with real-time temporal resolution can be utilized. 

Time of responses. The temporal expression of different biomarkers can vary widely from nearly instantaneous to years. Depending on the type of study, slow or rapid manifestation maybe desirable. 

When the pulse duration is much shorter than the nonlinear response time of the material (transient case), the third-order nonlinear susceptibility can be expressed in a phenomenological time-independent form similar to the one corresponding to the long-lasting pulse regime - the adiabatic case [68]. It is then a priori possible to compare the measurement results obtained in such opposite temporal regimes, provided the physical processes involved in the optical response remain exactly the same and, especially, are not intensity-dependent. This condition being fulfilled, the... 

Typical mass balance methods to measure the air-sea gas transfer have one major drawback the response time is of the order of hours to days, making a parameterisation with parameters such as wind forcing, wave field, or surface chemical enrichments nearly impossible. The controlled flux technique uses heat as a proxy tracer for gases to measure the air-sea gas transfer rate locally and with a temporal resolution of less than a minute. This method offers an entirely new approach to measure the air-sea gas fluxes in conjunction with investigation of the wave field, surface chemical enrichments and the surface micro turbulence at the water surface. The principle of this technique is very simple a heat flux is forced onto the water surface and the skin-bulk temperature difference across the thermal sublayer is measured. 

Let us define Yj. as the noisy temporal response (time series) of sensor j to stimulus... 

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