Reference levels

In preparation for a field wide quick look correlation, all well logs need to be corrected for borehole inclination. This is done routinely with software which uses the measured depth below the derrick floor ( alonghole depth below derrick floor AHBDFor measured depth , MD) and the acquired directional surveys to calculate the true vertical depth subsea (TVSS). This is the vertical distance of a point below a common reference level, for instance chart datum (CD) or mean sea level (MSL). Figure 5.41 shows the relationship between the different depth measurements. 

The solution comes out to be very similar to the Huckel solution for ethylene except that the two etiergy levels, specified as. are 5.96 eV above atid 5.96 eV below the reference level (Fig. 8-5). 

Under the nuU hypothesis, it is assumed that the sample came from a population whose mean [L is equivalent to some base or reference level designated by lo. For most applications of this type, the value of Io is defined to be zero that is, it is of interest generally to demonstrate a difference not equal to zero. The hypothesis can take one of three forms ... 

Reference level 0 is located in the center of the gate opening, i.e., 2 m above ground level. 

A zone represents a volume in the building which can be characterized by a single value each for its air temperature, its pressure at zone reference level, and the concentrarion of the individual contaminants considered. Thus, a zone is considered as a volume of perfectly mixed air. 

An external node represents a boundary node, i.e., a fixed pressure value or a location on the building facade which is linked to a specific set of vvind pressure coefficients for this location (a set of values for different wind directions Q ). The pressure at such a location e is then given by wind velocity at reference level p, air density) ... 

Network Zones Height of zone reference level Volume... 

L.inks Conductance type Zone connection (from/to) Height in relation to zone reference level Link factor (e.g., opening factor) Associated link schedules... 

A weighting scale, dBA The unit of sound intensity expressed as a logarithmic scale, related to a reference level of 10 W m"-. The A weighting scale is the most commonly used scale, as it reduces the response of sound meters to very high and low frequencies and emphasize those within the range audible by the human ear. 

Perfect or Absolute Vacuum) also. Absolute Reference Level... 

A different reference level, absolute pressure, is used to obtain the total pressure value. Absolute pressure is the total pressure, i.e., gage and atmospheric, and is expressed as psia or pounds per square inch absolute. To obtain absolute pressure, simply add the value of atmospheric pressure (14.7 psi at sea level) to the gage pressure reading. 

Since rms pressure variations have to be measured in the range 20 x 10 N/M to 200 N/M (a range of 10 ) it can be seen that an inconveniently large scale would have to be used if linear measurements were adopted. Additionally, it has been found that the ear responds to the intensity of a sound (a P ) in a logarithmic way. The unit that has been adopted takes these factors into account and relates the measured sound to a reference level. For convenience, this is taken as the minimum audible sound (i.e. 20 x 10 N/M) at 1 K. 

Vibration may also be expressed in decibels, and the standard reference levels used are ... 

The XPS spectra of the freshly sulfided Co-Mo/NaY catalysts were measured on an XPS-7000 photoelectron spectrometer (Rigaku, A1 anode 1486.6 eV). The sample mounted on a holder was transferred from a glove bag into a pretreatment chamber attached to the spectrometer as possible as carefully not to be contacted with air. The binding energies (BE) were referenced to the Si2p band at 103.0 eV for the NaY zeolite, which had teen determined by the Cls reference level at 285.0 eV due to adventitious carbon. 

It is well established that the Auger parameter is a very useful concept, which is not affected by the reference level used in the analysis of the data (the Fermi or the vacuum level) [75]. Moreover, the Auger parameter, being a difference between two peaks recorded on the same energy scale, does not depend on surface charging. It appears that Auger parameter measurements are very useful... 

All equilibrium constants in the present discussion are based on the concentration (not activity) scale. This is a perfectly acceptable thermodynamic scale, provided the ionic strength of the solvent medium is kept fked at a reference level (therefore, sufficiently higher than the concentration of the species assayed). This is known as the constant ionic medium thermodynamic state. Most modern results are determined at 25 °C in a 0.15 M KCl solution. If the ionic strength is changed, the ionization constant may be affected. For example, at 25 °C and 0.0 M ionic strength, the pXj of acetic acid is 4.76, but at ionic strength 0.15 M, the value is 4.55 [24]. 

Basic properties of semiconductors and phenomena occurring at the semiconductor/electrolyte interface in the dark have already been discussed in Sections 2.4.1 and 4.5.1. The crucial effect after immersing the semiconductor electrode into an electrolyte solution is the equilibration of electrochemical potentials of electrons in both phases. In order to quantify the dark- and photoeffects at the semiconductor/electrolyte interface, a common reference level of electron energies in both phases has to be defined. 

Let us choose, as an arbitrary reference level, the energy of an electron at rest in vacuum, e ) (cf. Section 3.1.2). This reference energy is obvious in studies of the solid phase, but for the liquid phase, the Trasatti s conception of absolute electrode potentials (Section 3.1.5) has to be adopted. The formal energy levels of the electrolyte redox systems, REDox, referred to o, are given by the relationship ... 

Gravity force can be measured by means of the mass of the water. The direction of the force is, obviously, downwards toward the Earth s center. The gravitational potential of soil water at each position is determined by the elevation of the position relative to some reference level. If we only consider the elevation potential and the related velocity energy, then a water body at a higher elevation will flow to a lower elevation, decreasing the elevation potential but increasing its velocity. 

Intervention measures have been proposed, based on the relationships between ACHE inhibition levels and biological effects (ICOH, 1986 Zielhuis, 1972). An ACHE decrease of 30% or less from the baseline (or 50% or less from the average reference level) requires medical surveillance and examination of working conditions. A reduction of more than 30% from baseline (or 50% from the reference level) requires temporary removal from exposure and careful evaluation of the working conditions. 

The partial pressure of C02 in the soil air controls the concentration of both dissolved C02 and undissociated carbonic acid. At 0.003 atm of C02 (g) as a reference level for soils, [H2C03°] is about 1.04 x 10 4 M (Lindsay, 1979). At a normal atmospheric level of 0.0003 atm C02 (g), [H2C03°] is approximately 1.04 x 10 5 M. In most soils, C02 (g) is higher than in the atmosphere. C02 is released from soil and plant root respiration. In flooded soils, C02 (g) partial pressure increases to 0.01-0.3 atm, about 1000-fold higher than normal upland soils due to strong microbiological activity (Lindsay, 1979). 

Two mid-term objectives are closely related to the principal goal of RP. The first of them has to do with encouraging price competition, as it provides an incentive for companies to bring their prices close to the reference level. This is precisely one of the reasons why the European Commission5 recommends RP. The second mid-term objective concerns incentives, as it takes into account the cost-effectiveness ratio of prescription drags by increasing the financial responsibility of patients, which in turn may influence prescriber decisions. It is important to note that, unlike in traditional co-payment, under this system the patient s share of the cost of the product is avoidable if the patient and/or doctor select a product with a price that does not exceed the reference price. 

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