Special units

Length. The nautical mile is a special unit employed for marine and aerial navigation to express distances. The conventional value was adopted by the 1st International Extraordinary Hydrographic Conference, Monaco, 1929, under the name International nautical mile. 

Except where otherwise noted here or in the text, either consistent system of units (SI or U.S. customary) may he used. Only SI units may he used for electrical quantities, since no comparable electrical units exist in the U.S. customary system. When special units are used, they are noted at the point of use. 

Symbols Definition SI units U.S. customary units Special units... 

Special Unit Study area of main use Symbol Equivalent in joules Other units... 

It is necessary to work with the manufacturer in sizing and rating these special units, because sufficient public data/ correlation of heat transfer does not exist to allow the design engineer to handle the final and detailed design with confidence. 

Some SR compartments (jSR) lie just beneath special microdomains of PM, and are joined to this PL by electron-dense processes (observed with electron microscopy). Na+ pumps with high-ouabain-affinity a. subunits (a2/a3 subunits), NCX and SOCs, appear to be confined to these PL microdomains. These PL microdomains, the subjacent jSR, and the intervening tiny cytosolic volume, form functionally specialized units we call PLasmERosomes. Through the operation of these units (which are apparently present in many types of cells), modulation of Na+ pump activity may have a profound influence on Ca2+ signalling in smooth muscles and many other types of cells. 

C M. Gordon, W. Leitner, Homogeneous Catalysis in Supercritical Solvents as a Special Unit Operation, in , B. Comils, W.A. Herrmann, D. Vogt, I. Horvath, H. Oli-vier-Bourbigon, W. Leitner, S. Mecking (Eds.), Multiphase Homogeneous Catalysis. Wiley-VCH, 2005. 

Rad Special unit of absorbed dose one rad equals an absorbed dose of 100 ergs/gram or 0.01 joule/kilogram (0.01 Gy). 

Rem (Roentgen equivalent in man) Special unit of any quantity expressed as a dose equivalent the dose equivalent in rems is equal to the absorbed dose in rads multiplied by the quality factor (1 rem = 0.01 Sv). 

Hydrometers are calibrated in density, specific gravity, and several arbitrary units such as degrees Baume (°Be), degrees American Petroleum Institute (°API), or °Brix. These units are used for specialized purposes in various industries. The relationship between the specific gravity (sp. gr.) of a liquid with a density less than water and these specialized units is given by the following equations ... 

Another method for describing polytypic structures has been suggested by Bokii and Laptev (1994). The polytypic structures, described by means of special unit... 

A number of non-SI units are commonly used in the literature of quantum chemistry. We therefore provide appropriate conversion factors for certain specialized units used in this chapter ... 

The bipolar plate with multiple functions, also called a flow field plate or separation plate (separator), is one of fhe core components in fuel cells. In reality, like serially linked batteries, fuel cells are a serial connection or stacking of fuel cell unifs, or so-called unif cells fhis is why fuel cells are normally also called sfacks (Figure 5.1) [2]. The complicated large fuel cells or module can consist of a couple of serially connecfed simple fuel cells or cell rows. Excepf for the special unit cells at two ends of a simple stack or cell row, all the other unit cells have the same structure, shape, and functions. 

The concept and quantity absorbed dose were introduced by the ICRU in 1951, with the special unit rad. A new special unit gray (Gy) was introduced in 1972 to be in correspondence with the SI system of quantities and units (Systeme International des Grandeurs et Unites) [11,12]. 

The total mass of an atom is called its atomic mass. This is the sum of the masses of all the atom s components (electrons, protons, and neutrons). Because electrons are so much less massive than protons and neutrons, their contribution to atomic mass is negligible. As we explore further in Section 9.2, a special unit has been developed for atomic masses. This is the atomic mass unit, amu, where 1 atomic mass unit is equal to 1.661 X 10-24 gram, which is slightly less than the mass of a single proton. As shown in Figure 3.21, the atomic masses listed in the periodic table are in atomic mass units. As is explored in the Calculation Corner on page 95, the atomic mass of an element as presented in the periodic table is actually the average atomic mass of its various isotopes. 

Spiral screws usually run at 1800-3600 rpm. Their capacity ranges up to 12,000 CFM or more. Normal pressure boost is 3-20 psi, but special units can boost pressures by 60-100 psi. In vacuum service they can produce pressures as low as 2 psia. Some other performance data are shown with Figure 7.19(d). 

Debye s technique is not always applicable and fails completely for complex, branched structures ( trees ). In such cases, a slightly different technique can be used. One special unit, say the j-th unit, can be selected as a reference point, and all pairs of units of the same path length can be grouped together, and the result may be summed over all path length occurring. We shall call the reference unit the root of the tree . To get the total double sum, each unit has to be selected as a root and the result of the summation over the different trees has to be added. This leads to the final result... 

ACTIVITY (Radioactivity). The activity of a quantity of radioactive nuclide is defined by the 1CRU as AN/At, where N is the number of nuclear transformations that occur in this quantity in time At. The symbol A preceding the letters N and t denotes that these letters represent quantities that can be deduced only from multiple measurements that involve averaging procedures. The special unit of activity is the curie, defined as exactly 3.7 x 10l° transformations per second. See Radioactivity. 

Every held has its own special units of measure and nuclear chemistry is no different. The unit of length is the femtometer (10-15 m), which is called a fermi. The unit of mass is the atomic mass unit (amu or u), which has a numerical value of 1.66 x 10 24 g or expressed in units of MeV/c2, it is 931.5 MeV/c2. The unit of energy is MeV (106eV), which is 1.602 x 10 13 J, the energy gained when a proton is... 

As studies of the effects of exposure to all types of radiation went on, it became clear that these effects were correlated with the amount of absorbed energy, which is generally less than the exposure. In 1962 the rad was formally defined as a special unit of energy called the radiation absorbed dose with a value of 100 ergs per gram of absorbing material. The rad is a convenient physical standard that correlates well... 

When referring to the enormous numbers of molecules or ions that take part in a visible chemical reaction, it s convenient to use a special unit called a mole, abbreviated mol. One mole of any substance is the amount whose mass—its molar mass—is equal to the molecular or formula mass of the substance in grams. One mole of ethylene has a mass of 28.0 g, one mole of HC1 has a mass of 36.5 g, one mole of NaCl has a mass of 58.5 g, and so on. (To be more precise, one mole is formally defined as the amount of a substance that contains the same number of molecules or formula units as there are atoms in exactly 12 g of carbon-12.)... 

Because the mass of an atom is very small, it is convenient to define a special unit that avoids large negative exponents. This unit, called the atomic mass unit and designated by the symbol u (some authors use the abbreviation amu), is defined as exactly 1/12 the mass of a 12C atom. 

The masses of individual atoms are very small. Even the heaviest atom discovered has a mass less than 5 x 10-25 kg. Since 1 kg is 2.21b, the mass referred to is less than 1.10 x 10-24 lb. It is convenient to define a special unit in which the masses of the atoms are expressed without having to use exponents. This unit is called the atomic mass unit, referred to by the symbol u in the literature. It is defined as exactly the mass of a 12C atom. The mass of the 12C atom is taken to be exactly 12u the mass of the 23Na atom is 22.9898 u. Table 2-1 lists the masses of some nuclides to which reference will be made in this chapter, as well as others. 

The standard ranges of displacement level transmitters are from 36 to 150 cm (14 to 60 in.), whereas special units are available up to 18 m (60 ft). Their error... 

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