Beta phase

The thermal transitions of the manganese dioxides can be iUustrated by the beta phase which undergoes successive reductions and corresponding loss of oxygen as the temperature is increased (49). 

The Zn—A1 system permits manipulation of the mechanical properties by suitable heat treatment. The aluminum-rich alpha phase is especially suitable for solution hardening since it can be supersaturated by as much as 30 wt % zinc. Furthermore, both alpha and beta phases can be strengthened by precipitation because of decreasing solute solubiUty with decreasing temperature. 

This computation is also referred to as calculating the zinc equivalent of the alloy. The increase in strength in this alloy series is caused by increased amounts of beta phase in the stmcture. The silicon brasses show similar hardening effects accompanying a second phase. Typical mechanical properties and electrical conductivity for various cast alloys are shown in Table 2. 

Half-life is the time taken to decrease the concentration of a drug to one-half its original value. There may be several phases in the elimination, and the most common is the so-called beta-phase. Alpha-phase is a distribution phase and gamma-phase is the terminal phase when the drug is finally leaving the tissues. 

For bi-exponential accumulation kinetics the contribution of the fast alpha phase (Ralpha = 1/(1 - exp(-alpha Tau))) decreases (Ralpha Ca Rbeta Cb) as compared with the contribution of the slow beta-phase (Rbeta = 1/(1 - exp(-beta Tau))). 

As has been confirmed by XRD, the framework of montmorillonite has been partly destroyed due to the calcination under high temperature. Most diffraction peaks of montmorillonite are faint. After hydrothermal crystallization the characteristic Bragg reflections for zeolite Beta structure at 7.7° and 22.42° 20 are detected in the composite, indicating the presence of the Beta phase. 

P-parinaric acid, physical properties, 5 33t P-pentenoic acid, physical properties, 5 3 It P-peroxylactones, 18 484 Beta phase titanium, 24 838 in alloys, 24 854-856 properties of, 24 840, 941 P-phellandrene, 24 493 P-picoline, 21 110 from acrolein, 1 276 uses for, 21 120 P-pinene, 3 230 24 496-497 major products from, 24 478 /-menthol from, 24 522 as natural precursor for aroma chemicals, 3 232 terpenoids from, 24 478-479 P-propiolactone, polymerization of, 14 259 P-quartz solid solution, 12 637—638 Beta ratio, in filtration, 11 329—330 Beta (P) rays, 21 285 P-scission reactions, 14 280-281 P-skytanthine, 2 101 P-spodumene solid solution, 12 638-639 P-sulfur trioxide, 23 756 P-sultones, 23 527 P-tocopherol, 25 793 P-tocotrienol, 25 793 P-vinylacrylic acid, physical properties, 5 33t... 

After intravenous administration, dihydroergotoxine aikaioids show maximai uptake in viscerai organs (10-5 M) and the centrai nervous system (10-7 M), and concentrations increase with repeated administration (Iwangoff et ai. 1978). Maximai piasma concentrations of ergoioids occur approximateiy 2 hours after orai administration (Aeiiig and Nuesch 1977). Eiimination haif-iife varies from 1.4 to 6.2 hours for the aipha phase and from 13 to 50 hours for the beta phase. 

The beta phase is a metastable aUotrope with white, asbestos-hke, lustrous needles consisting of polymeric molecules, melting at 32.5°C, and with vapor pressure 344 torr at 25°C. 

The metal exists in three crystal forms an orthorhombic alpha phase, density 18.97 g/cm3 and stable to 667°C a tetragonal beta phase of density 18.11 g/cm3, stable between 688 to 776°C and a body-centered cubic form of density 18.06 g/cm3 and stable in the range 776 to 1,132°C. Other physical properties are listed below ... 

URANIUM. [CAS 7440-61-1], Chemical element symbol. U, at. no. 92, at. wt, 238,03, periodic table group (Actinides), mp 1,131 to i. 33°C, bp 3,818°C, density 18.9 g/cm3 (20UC). Uranium metal is found in three allotropic forms (1) alpha phase, stable below 668°C, orthorhombic (2) beta phase, existing between 668 and 774°C. tetragonal and (3) gamma phase, above 774°C, body-centered cubic crystal structure. The gamma phase behaves most nearly that of a true metal. The alpha phase has several nonmetallic features in its crystallography. The beta phase is brittle. See also Chemical Elements. 

ZIRCONIUM. [CAS 7440-67-7]. Chemical element symbol Zr. at. no. 40, at. wt. 91.22, periodic table group 4. mp l,853°C, bp 4,376°C, density 6.44 g/cm3, 6.47 g/cm3 (single crystal). Metallic zirconium is allotropic. Up to about 863°C, the alpha phase (hexagonal close-packed) is stable above this temperature, the metal assumes the beta phase (body-centered cubic). The most common impurity, oxygen, tends to stabilize the alpha phase. 

A typical kinetic profile is divided into alpha and beta phases. The alpha phase occurs rapidly (in the first 24 h) and is considered to be the period in which the administered antibody reaches equilibrium. The beta phase then continues for several days in a direct log-linear relationship of serum concentration to time. It is this beta phase that is considered to be the most reliable indicator of antibody half-life in circulation. To establish beta phase kinetics, we take blood samples (25-75 xl depending on the frequency of sampling) at 1-4 days following administration, followed by... 

The beta phase clearance kinetics of human IgG and therapeutic antibodies is typically monophasic and abides to a log-linear relationship of serum concentration with time after administration. However, in rare cases we have found that certain administered mAbs are immunogenic to the mouse and elicit mouse-anti-human antibodies. In this case, there is a bi-phasic kinetic, typically appearing at days 5-6 after antibody administration and resulting in a precipitous antibody loss. This complication can be overcome by the use of immunodeficient hFcRn transgenic mice, described in Section 3.7. 

This system is not useful for representing a biochemical system but is needed as a foundation. The fundamental equation for G for a system containing alpha and beta phases... 

We carried out a study in the dog to determine the formation of ll-hydroxy-A9-THC from A9-THC. In the first stage we injected 11-hydroxy-A9-THC in order to determine the beta phase half-life of the metabolite the half-life was approximately 1.5 hours. However, when A9-THC was administered to the same dog either orally or intravenously the metabolite was not detectable. 

A lower Al content definitely leads to the Si richer Beta phase, that incorporates TEA+ counterions to Al negative charges and TEAOH ionic pairs, that occupy the maximum of the intracrystalline free volume, while Na+ ions partly neutralize the Si-O" framework defect groups. 

The beta phase consists of a combination of arrangements in which each corner and each face-centered palladium atom is surrounded by four and only four nearest neighbor hydrogen atoms. 

For the composition Pd2H there are no atoms in the alpha phase. We have set the composition 0.5 H/Pd ratio as the limit of the beta phase in accord with the numerology of the model. Consideration of the d-band places this figure at 0.60. However, the hydrogen atoms themselves will modify the lattice and it is difficult to get a consistent model of the beta phase which gives it a composition other than H/Pd = 0.5 (6). Obviously the neutron diffraction data require a composition Pd/H = 0.5. 

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