Effect occurence

Some fascinating effects occur in the case of CO on Pt(lOO). As illustrated in Fig. XVI-8, the clean surface is reconstructed naturally into a quasi-hexag-onal pattern, but on adsorption of CO, this reconstruction is lifted to give the bulk termination structure of (110) planes [56]. As discussed in Section XVIII-9E very complicated changes in surface structure occur on the oxidation of CO... 

In an ideal Bose gas, at a certain transition temperature a remarkable effect occurs a macroscopic fraction of the total number of particles condenses into the lowest-energy single-particle state. This effect, which occurs when the Bose particles have non-zero mass, is called Bose-Einstein condensation, and the key to its understanding is the chemical potential. For an ideal gas of photons or phonons, which have zero mass, this effect does not occur. This is because their total number is arbitrary and the chemical potential is effectively zero for tire photon or phonon gas. 

Large stepsizes result in a strong reduction of the number of force field evaluations per unit time (see left hand side of Fig. 4). This represents the major advantage of the adaptive schemes in comparison to structure conserving methods. On the right hand side of Fig. 4 we see the number of FFTs (i.e., matrix-vector multiplication) per unit time. As expected, we observe that the Chebyshev iteration requires about double as much FFTs than the Krylov techniques. This is due to the fact that only about half of the eigenstates of the Hamiltonian are essentially occupied during the process. This effect occurs even more drastically in cases with less states occupied. 

The dielectric constant (permittivity) tabulated is the relative dielectric constant, which is the ratio of the actual electric displacement to the electric field strength when an external field is applied to the substance, which is the ratio of the actual dielectric constant to the dielectric constant of a vacuum. The table gives the static dielectric constant e, measured in static fields or at relatively low frequencies where no relaxation effects occur. 

Fixed orSlowlj M-OvingFeds. For fuel-bed burning on a grate, a distillation effect occurs. The result is that hquid components which are formed volatilize before combustion temperatures are reached cracking may also occur. The ignition of coal in a bed is almost entirely by radiation from hot refractory arches and from the flame burning of volatiles. In fixed beds, the radiant heat above the bed can only penetrate a short distance into the bed. 

A similar effect occurs in highly chiral nematic Hquid crystals. In a narrow temperature range (seldom wider than 1°C) between the chiral nematic phase and the isotropic Hquid phase, up to three phases are stable in which a cubic lattice of defects (where the director is not defined) exist in a compHcated, orientationaHy ordered twisted stmcture (11). Again, the introduction of these defects allows the bulk of the Hquid crystal to adopt a chiral stmcture which is energetically more favorable than both the chiral nematic and isotropic phases. The distance between defects is hundreds of nanometers, so these phases reflect light just as crystals reflect x-rays. They are called the blue phases because the first phases of this type observed reflected light in the blue part of the spectmm. The arrangement of defects possesses body-centered cubic symmetry for one blue phase, simple cubic symmetry for another blue phase, and seems to be amorphous for a third blue phase. 

A substantial effort has been appHed to iacreaskig i by stmctural modification (114), eg, the phthalaziQe-l,4-diones (33) and (34) which have chemiluminescence quantum yields substantially higher than luminol (115,116). The fluorescence quantum yield of the dicarboxylate product from (34) is 14%, and the yield of singlet excited state is calculated to be 50% (116). Substitution of the 3-amino group of lumiaol reduces the CL efficiency > 10 — fold, whereas the opposite effect occurs with the 4-amino isomer (117). A series of pyridopyridaziae derivatives (35) have been synthesized and shown to be more efficient than luminol (118). 

Dual-beUows assembhes, ie, universal-type expansion joints, are particularly vulnerable to squirm, and can experience elastic squirm at one-fourth the pressure of an individual bellows. When large amounts of offset are encountered, as is often the design basis, a pinwheel effect occurs because of unbalanced pressure forces. This effect tends to rotate the center-spool pipe which may lead to bellows mpture. Eor this reason the center spool should always be stabilized by hinges or tie-rod lugs to prevent such rotation. 

Latent effects occur either only after there has been a significant period free of toxic signs following exposure, or after resolution of acutely toxic effects which appeared immediately following exposure. They are also referred to as delayed-onset effects. 

Acute Toxicity Studies. These studies should provide the following information the nature of any local or systemic adverse effects occurring as a consequence of a single exposure to the test material an indication of the exposure conditions producing the adverse effects, in particular, information on dose—response relationships, including minimum and no-effects exposure levels and data of use in the design of short-term repeated exposure studies. 

The side effects of diltia2em therapy are less than those of verapamil or nifedipine therapy. Side effects occur in about 4% of the patients (1,98,99). 

Po adrninistered nifedipine is almost completely absorbed. The onset of action is 20 min and peak effects occur at 1—2 h. The principal route of elimination is through hepatic metaboHsm by oxidation to hydroxycarboxyHc acid and the corresponding lactone. These metaboHtes are pharmacologically inactive. Almost 70—80% of dmg is eliminated in the urine during the first 24 h. About 15% is excreted in the feces. The elimination half-life of nifedipine is about 1—2.5 h (1,98,99). Frequency of occurrence of side effects in patients is about 17% with about 5% requiring discontinuation of therapy (1,98,99). 

When adininistered orally, digoxin bioavailabihty ranges from 40 to 90% depending on the manufacturing process. Peak plasma levels occur within 3 h after oral adininistration peak effects occur 2 h later. The dmg is elkninated primarily through the kidney (114). 

Because colestipol and cholestyramine are not absorbed, but simply pass through the body by the GI tract, few severe side effects occur. Patients often complain of distaste and constipation, however. More severe side effects such as GI bleeding ate relatively uncommon (151). 

Probucol. Probucol is an antioxidant that is effective in lowering LDL cholesterol. Whereas probucol was known to lower cholesterol after relatively simple clinical trials (160), its mechanism of action as an antioxidant in the treatment of atherosclerosis is quite novel. Probucol has been shown to have the abiUty to produce regression of atherosclerotic lesions in animal models (161). Probucol therefore represents a novel class of pharmaceutical agent for the treatment of atherosclerosis. This effect occurs mechanistically, in part, by preventing oxidation of LDL, a necessary step in foam cell formation. This antioxidant activity has been shown in laboratory experiments and its activity in lowering LDL cholesterol in human studies is well documented (162). 

An acute lethal dose (LC q) for vapor exposure to 1,1,2-trichloroethane in the rat is 2000 ppm for a 4-h exposure. The same lethal effect occurs at 18,000 ppm vapor during 3 h exposure to 1,1,1-trichloroethane. The oral LD q for 1,1,2-trichloroethane in rats is 0.1—0.2 g/kg, classifying it as moderately toxic (109). Liver and kidney damage occurs at even lower dosages. Skin adsorption is a possible route of overexposure. 

The thia2ides are actively secreted into the proximal tubules, where they exert their action on the luminal side of the tubules. The diuretic effect occurs within 1 h after oral adininistration, and the duration of action varies from 4 to 24 h depending on which thia2ide-type diuretic is used. The diuretic effects of the thia2ides are not influenced by acid—base conditions of the blood or urine. Probenecid, which also is secreted into the proximal tubules, may block the diuretic effects of the thia2ides. 

Curved Pipes and Coils For flow through curved pipe or coil, a secondary circiilation perpendicular to the main flow called the Dean effect occurs. This circulation increases the friction relative to straight pipe flow and stabilizes laminar flow, delaying the transition Reynolds number to about... 

From the commencement of the fog and low visibility, many people experienced difficulty breathing, the effects occurring more or less simultaneously over a large area of hundreds of square kilometers. The rise in the number of deaths (Fig. 18-4) paralleled the mean daily smoke and sulfur dioxide concentrations daily deaths reached a peak on December 8 and 9, with many of them related to respiratory troubles. Although the deaths decreased when the concentrations decreased, the deaths per day remained considerably above the pre-episode level for some days. Would most of the persons who died have died soon afterward anyway If this were the case, a below-normal death rate would h ve occurred following the episode. This situation did not seem to exist, but detailed analysis was complicated by increased deaths in January and February 1953 which were attributed primarily to an influenza outbreak. 

Even though some refiners have reported that caustic reduces corrosion, others have reported increased corrosion. The authors believe that for the reported MEA and DEA systems a temporary beneficial effect occurs related to high CO2 loadings in these solutions. The effect is only temporary. 

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