Events instrumentally detectable

The reproducibility of an effect requires the ability to exploit a specimen s causal properties. Again, for both an absorption spectrometer and a Raman spectrometer, a signal is produced from a complex system in which a specimen reacts to instrumental agitations. Such a reaction is caused by an internal change of the compound s dynamic state. As a specimen in laboratory research, a chemical compound is characterized by its capacities for change. A specimen is known by its tendencies to permit interference from radiation and to react to certain manipulations, leading to the causal production of instrumentally detectable events. In Raman spectroscopy, for example, a specimen is a system of causal properties, which, under appropriate laboratory conditions, produce an inelastic scattering of radiation, known as the Raman effect. 

The average and the range of Cs and activities found in nectar honey (meadow nectar, bush-tree, and mixed honey) that was collected between 1990 and 1996 in Croatia are presented in Table 10.3. Previously documented trends showed year to year reductions in the activity levels of Cs in bush-tree and meadow nectar honey types [19,37]. This finding was confirmed by following the Cs activity in nectar honey types up to 1996. Ten years after the serious cesium contamination event of the Chernobyl accident, Cs activity in nectar honey types has become very low, frequently below the instrument detection limit. On the basis of data presented in Table 10.3, it is evident that for each successive year, Cs activity in nectar... 

Until recently, limitations in spatial resolution made PET studies in small animals impossible. Eor instance, most PET scanners in clinical use have an image spatial resolution of 10-15 mm (although more recent instruments can achieve resolution approaching 1-2 mm) the mouse lung, in contrast, is 10mm wide. Other issues such as scanner sensitivity (i.e., the fraction of radioactive events actually detected by the device) and the amount of radioactivity... 

This sequence of events is quite rapid. If we take typical instrumental conditions of the LIMA 2A, where the UV laser pulse duration is 5-10 ns, the fight path is "2 m, and the accelerating potential is 3 kV, then an ion arrives at the detector i n approximately 3 ps, and a ion arrives at the detector in approximately 40 ps. Since the time width of an individual signal can be as short as several tens of nanoseconds, a high speed detection and digitizing system must be employed. 

Various simple and sophisticated fire and gas detection systems are available to provide early detection and warnings of a hydrocarbon release which supplement process instrumentation and alarms. The overall objective of fire and gas detection systems are to warn of possible impending events that may be threatening to life, property of continued business operations, that are external to the process operation. 

Other properties that define instrument capahihty include sensitivity, hmits of particle size resolution, and rate of data acquisition. For example, detection limits for green fluorescence range from 600 molecules of equivalent soluble fluorochrome (MESF)/cell to <50 MESF/cell, and particle sizes of 0.5 pm to 50 pm may be resolved in some instruments. Acquisition rates in analytical instruments vary from <3,500 cells (events)/s in older instruments, to 10,000 events/s in the newest models. High acquisition rates and the availability of automatic samphng devices for microplate-based assays have enhanced the efficiency of analyzing large sample sets. 

Development and application of nanobiotechnology and biomedical instrumentation, e.g., of biosensors and bioarrays for detection of biological events and their conversion to electrical... 

For most measurement techniques a trade-off exists between time response and sensitivity. Instruments can be made to respond more rapidly, but then noise levels and detection limits increase. To fulfill certain measurement objectives for which sensitivity is not a problem, it may be useful to enhance the time response of the instrument and accept the decrease in sensitivity. In any event, careful consideration must be made in the design of any sampling program to ascertain what level of concentrations needs to be measured and what time-space resolution is required. These issues will determine the characteristics of the airborne platform and the instruments that will be used and will dictate how they will be deployed. 

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