Trimodal

The mode of distribution is simply the value of the most frequent size present. A distribution exhibiting a single maximum is referred to as a unimodal distribution. When two or more maxima are present, the distribution is caUed bimodal, trimodal, and so on. The mode representing a particle population may have different values depending on whether the measurement is carried out on the basis of particle length, surface area, mass, or volume, or whether the data are represented ia terms of the diameter or log (diameter). 

Product crystals are trimodal, spread closely around size of seed crystals and initial nuclei and more broadly around small size... 

This new edition not only includes information on the newer materials but attempts to explain in modifications to Chapter 2 the basis of metallocene polymerisation. Since it is also becoming apparent that successful development with these polymers involves consideration of molecular weight distributions an appendix to Chapter 2 has been added trying to explain in simple terms such concepts as number and molecular weight averages, molecular weight distribution and in particular concepts such as bi- cmd trimodal distributions which are becoming of interest. 

Zorbax PSM Bimodal and Trimodal columns are packed with mixed pore-size packing to achieve linear size separations over a broad molecular weight range (Table 3.3). Zorbax PSM Bimodal columns are packed with PSM 60 and PSM 1000 particles, and Trimodal columns contain PSM 60, PSM 300, and PSM 3000 particles (Fig. 3.4). Carefully selecting and mixing different pore-size particles in columns provide much better linearity than coupling columns that are each packed with single pore-size particles. 

FIGURE 3.4 Calibration plots for Zorbax PSM Bimodal and Trimodal columns. 

A trimodal distribution is a frequency distribution of a certain phenotype with three peaks separated by two antinodes. 

Because of the improvements in properties exhibited by elastomers having bimodal distributions [5], there have been attempts to prepare and characterize "trimodal" networks [56]. The calculations suggest that adding a small amount of very high molecular weight end-linkable polymer could further improve mechanical properties. 

Most bimodal networks synthesized to date have been prepared from PDMS [88], One reason for this choice is the fact that the polymer is readily available with either hydroxyl or vinyl end groups, and the reactions these groups participate in are relatively free of complicating side reactions. These ideas can obviously be extended to higher modalities (trimodal, etc., eventually approaching an extremely broad, effectively-unimodal distribution) [102-104],... 

Although there have been attempts to evaluate the mechanical properties of trimodal elastomers, this has not been done in any organized manner. The basic problem is the large number of variables involved, specifically three molecular weights and two independent composition variables (mol fractions) this makes it practically impossible to do an exhaustive series of relevant experiments. For this... 

TMPT activity in human erythrocytes is transmitted as an autosomic codominant trait [15] and is trimodally distributed, with 89-94% of the individuals having high, 6-11% intermediate, and 0.3% low activity [7, 15-17] (Figure 14.2). The measurement of TPMT activity in erythrocytes closely reflects the ability of bone marrow to inactivate 6-MP. TPMT activity is inversely related to erythrocyte 6-TGN levels [7, 13, 18, 19], and children with low TPMT activity and very high 6-TGN levels experienced profound myelotoxicity [20, 21]. Moreover, TPMT phenotype in erythrocyte reflects that in leukemic blasts [22]. Patients with intermediate TPMT activity had a 5-fold greater cumulative incidence of dose reductions than subjects with high activity [13], and TPMT activity has been inversely related to the time of treatment withdrawal due to cytopenia [21]. 

Trade secret protection, 110, 119-122 Training programs, 155-157 Transgenic mice, 42 Transkaryotic Therapies, 130 Translating Research Into Practice (TRIP) initiative, 324 Translational research, 323-324 Trazodone, 221 Treatment disparities, among minorities, 275-278 Treatment population, 91 Treatments, more effective, 125 Treatment substitution, 238 Trimodal distributions, 166 Trust... 

Figure 3.12 The low shear limiting viscosity for unimodal, bimodal and trimodal size distributions calculated from Equation (3.55 )...

Whitby and Cantrell (16) report that aerosols collected near the surface of the earth are trimodal in nature. As listed in Table IV, these consist of distributions arising from (1) the irect emission of primary products from combustion having d = 0.02 un (2) coagulation of the aerosols from (1), or the c6ndensation of reaction products or water on the aerosols from (1), having = 0.16 and (3) larger particles arising from... 

Trimodal Nature of Surface Aerosols as Proposed by Whitby and Cantrell (16)... 

Fig. 11.18 shows experimental results concerning the frichon sensihvity of mixtures of AP parhcles and catalysts.Iil The AP parhcles are trimodal mixtures with diameters of 200 pm (33%), 35 pm (33%), and 5 pm (34%). Catocene (C27H32pe2) and ferrocene (CjoHjoFe) are both liquid organic compounds with iron atoms in their molecular structures and carborane is a liquid compound that contains boron atoms.Ii] The physicochemical properhes of -hexyl carborane are shown in Table 11.7. These catalysts are used to increase the burning rate of AP pyrolants. 

Fig. 14. The distribution of cysteine-metal ion torsion angles, Ca-C/3-S-M , in protein structures is trimodal, with peaks at 90° and 180° this distribution holds for M" = Zn. [Reprinted with permission from Chakrabarti, P. (1989). Biochemistry 28, 6081-6085. Copyright 1989 American Chemical Society.]...

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