Electromagnetic environment

The internal field is that microwave field which is generally the object for solution when MaxweU s equations are appUed to an object of arbitrary geometry and placed in a certain electromagnetic environment. The is to be distinguished from the local field seen by a single molecule which is not necessarily the same (22). The dielectric permittivity as a function of frequency can be described by theoretical models (23) and measured by weU-developed techniques for uniform (homogeneous) materials (24). 

Electromagnetic Capability (EMC) The capability of electronic equipment of systems to be operated in the intended operational electromagnetic environment at designed levels of efficiency. 

The difference in resonance NMR frequency of a chemically shielded nucleus measured relative to that of a suitable reference compound is termed chemical shift [164,165], and is a measure of the immediate electromagnetic environment of a nucleus. While the chemical shift depends on the Bo field, J does not. Chemical shifts, which cover a range of about 10 ppm for protons (i.e. 600 Hz in case of a 14.1 kG magnetic field) and 250 ppm for 13C, are the substance of NMR. 

We now check whether Eq. (1), with S /3 = e2/ and modified as above to account for finite propagation time, can explain our data. The unknown parameters are the resistance Rq and the effective environment noise temperature Tq. We checked that the impedance of the samples was frequency independent up to 1.2 GHz within 5%. Fig. 2 shows the best fits to the theory, Eq. (1), for all our data. The four curves lead to Ro = 42 12, in agreement with the fact that the electromagnetic environment (amplifier, bias tee, coaxial cable, sample holder) was identical for the two samples. We have measured the impedance Zenv seen by the sample. Due to impedance mismatch between the amplifier and the cable, there are standing waves along the cable. This causes Zenv to be complex with a phase that varies with frequency. We measured that the modulus Zenv varies between 30 12 and 70 12 within the detection bandwidth, in reasonable agreement with f o = 42 12 extracted from the fits. 

Since specific heats, dielectric constants and dielectric loss factors are not available in the literature for most of the commonly used flavor ingredients, we searched for alternate criteria to evaluate flavor raw materials. Thus, early in 1985 we embarked on a research project to analyze over 500 chemicals, solvents, essential oils and natural flavoring components that were carefully selected to represent the thousands of raw materials used in the flavor industry. All were analyzed individually in the HWO to determine their characteristic behavior within the electromagnetic environment. 

Electromagnetic compatibility (EMC) is therefore defined as the ability of equipment or systems to share the electromagnetic environment (much like we share our freeways). Devices should operate satisfactorily, without either inducing (emitting) or experiencing interference from others. Note that the sensitivity of a device to electromagnetic fields is alternatively described as its immunity rather than its susceptibility. 

Part 2 Environmental - Section 1 Description of the environment electromagnetic environment for low-frequency conducted disturbances and signaling in public power supply systems. 

Very similar information can be obtained with the experimentally less demanding Mossbauer spectroscopy. The resonant absorption of gamma radiation by certain atomic nuclei ( Fe, Sn and several other isotopes of technical interest, e.g. Co, can also be studied in the emission mode) yields information about the electromagnetic environment of this atom. By comparison with standard samples the chemical environment of a given atom, the specific type of chemical compound wherein it is incorporated and further morphological information can be derived Irom the Mossbauer spectra [104-113]. 

Assessing the electromagnetic environment of the facility and identifying critical medical device use areas... 

Managing the electromagnetic environment, RF transmitters, and all electrical and electronic equipment, including medical devices, to reduce the risk of medical device EMI and achieve EMC... 

Funnan S, Parker B, Krauthammer J, Esher DJ. The influence of electromagnetic environment on the performance of artificial cardiac pacemakers. Am Thorac Surg 1968 6 90. 

Electromi etic compatibility (EMC) The abihty of a product to coexist in its intended electromagnetic environment without causing or suffering functional degradation or damage. 

Ambient electromagnetic environment The radiated or conducted electromagnetic signals and noise at... 

Electromagnetic compatibility The capability of electronic equipment or systems to operate in a specific electromagnetic environment, at designated levels of efficiency and within a defined margin of safety, without interfering with itself or other systems. 

The safety related equipment sensitive to electromagnetic radiation should first be identified. The equipment should be qualified by testing to show that it can withstand the electromagnetic environment in which it should work. Alternatively it should be shielded or moved from that environment. 

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