RMS acceleration

Muzaffer MA, Schneider R, Cameron BJ, Silverman ED, Laxer RM. Accelerated nodulosis during methotrexate therapy for juvenile rheumatoid arthritis. J Pediatr 1996 128(5 Pt 1) 698-700. 

Vibration Perception. The perception of vibration depends on the body site and on the stimulus firequency. The thresholds in Table 10.2 are typical of those for healthy adults, and are expressed as instantaneous RMS accelerations (i.e., with T 1 s in Eq. (10.2)). The value for whole-body vibration is given in terms of a frequency-weighted acceleration, and so is applicable to vibration at frequencies from 1 to 80 Hz. The values for hand-transmitted vibration are for sinusoidal stimuli applied to the fingertips of males (M) and females (F) at the specified frequencies. 

EXAMPLE 10.2 A worker uses a percussive rock drill for 3 hours daily. Measuremeta of the handle vibration indicates a frequency-weighted RMS acceleration of 18 mJs along the drill axis, and a frequency-weighted RMS acceleration of 5 mJs perpendicular to this axis. Estimate the 8-hour daily exposure. 

During white noise exploratory testing, a random noise signal of bandwidth 1-100 Hz and RMS acceleration = O.OOSg was employed. During each exploratory... 

Root-mean-square (RMS) is the statistical average value of the amplitude generated by a machine, one of its components, or a group of components. Referring to Figure 43.11, RMS is equal to 0.707 of the zero-to-peak value, A. Normally, RMS data are used in conjunction with relative vibration data acquired using an accelerometer or expressed in terms of acceleration. 

Broadband analysis techniques have been used for monitoring the overall mechanical condition of machinery for more than twenty years. The technique is based on the overall vibration or energy from a frequency range of zero to the user-selected maximum frequency, Fmax Broadband data are overall vibration measurements expressed in units such as velocity (PK), acceleration (RMS), etc. This type of data, however, does not provide any indication of the specific frequency components that make up the machine s vibration signature. As a result, specific machine-train problems cannot be isolated and identified. 

Hoogenboom R, Fijten MWM, Paulus RM et al. (2006) Accelerated pressure synthesis and characterization of 2-oxazoline block copolymers. Polymer 47 75-84... 

Wilson RM, I-oveday JS, Nehnes RJ, Klotz S, Marshall WG (1995) Nuclear Instmm Methods Phys Res Sect A Accelerators Spectrometers Detectors and Associated Equipment 354(1) 145. Third Workshop on Neutron Scattering Data Analysis (WONSDA 94), Chilton, England, 13-15 Apr 1994... 

Continuous phase liquid holdup profiles (CPLHP) for different ionic strengths for droplet size / = 50bcl0 m, centrifugal acceleration = l(rm /sec, surface concentration r=5xlG k /m, thickness of adsorbed protein layer Lg = 12xl0" m and zeta potential = 12mV. 

Altshuler LL, Post RM, Leverich GS, et al. Antidepressant induced mania and cycle acceleration a controversy revisited. Am J Psychiatry 1995 152 1130-1138. 

The radius of trajectory rm in cm of an ion on its circular path through a homogeneous magnetic sector field with magnetic force (gauss) and accelerating voltage V (volts) is determined by ... 

As a safety precaution against EXPLOSION (in case the purification has been insufficiently thorough) at least a quarter of the total volume of ether should remain in the distilling flask when the distillation is discontinued. To minimize peroxide formation, ethers should be stored in dark bottles and, if they are liquids, they should be left in contact with type 4A Linde molecular sieves, in a cold place, over sodium amalgam. The rate of formation of peroxides depends on storage conditions and is accelerated by heat, light, air and moisture. The formation of peroxides is inhibited in the presence of diphenylamine, di-rm-butylphenol, or other antioxidant as stabilizer. 

The stability is another critical aspect for RM use it has to be verified in relation to the purpose of the study, e.g. over the duration of an interlaboratory study, or over long-term storage periods (for CRMs). The (in)stability should be studied or known before the RM is produced and should be monitored on the batch of RM. Studies may be performed under accelerated ageing conditions, e.g. elevated temperatures, or at various temperatures over defined periods of time. The BCR has developed a strategy with respect to stability assessment which has been successfully used for a wide variety of chemical species as described later in this chapter. Full details on the organisation of such studies are described elsewhere (Quevauviller et al., 1996a Quevauviller, 1998b). 

Answer The first important thing to note is that the temperature is given in degrees Celsius and must be converted to Kelvin. The second important consideration is the units of the molar gas constant, R. The joule is a unit of energy that represents a Newton meter (N-m) in physics. The Newton is a unit of force equivalent to the amount of force required to accelerate a 1 kg mass at 1 m/s2. Why does this matter, you might ask Because it means that a joule can be described as a Newton meter, which is 1 kg m2/s2. Can you see the problem yet The mass unit associated with joules is the kilogram. Molar mass is usually expressed in grams/mole. To use the rms equation, you have to convert your mass units to kg. 

Sridhar M, Rao RM, Baba NHK et al (2007) Microwave accelerated Gewald reaction synthesis of 2-aminothiophenes. Tetrahedron Lett 48 3171-3172... 

Mohajeri MH, Saini KD, Nitsch RM (2004) Transgenic BACE expression in mouse neurons accelerates amyloid plaque padiology. J Neural Transm 111 413 25. 

Yamamoto M, Horiba M, Buescher JL, Huang D, Gendelmaii HE, Ransohoff RM, Ikezu T (2005) Overexpression of monocyte che-motacdc protein-1/CCL2 in beta-amyloid precursor protein transgenic mice show accelerated diffuse beta-amyloid deposidoii. Am J Padiol 166 1475-1485. 

Castellanos A, Shin EK, Luceri RM, Myerburg RJ. Parasystolic accelerated idioventricular rhythms producing bidirectional tachycardia patterns. J Electrophysiol 1988 2 296. 

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