Discontinuity, concept

Ward JV, Stanford FR (1983) The serial discontinuity concept of lotic ecosystems. In Fontaine TD, Bartell SM (eds) Dynamics of lotic ecosystems. Ann Arbor Science, Ann Arbor, pp 29-42... 

Pfundt [6] differentiates existing answers not only in regard to a continuous concept or discontinuous concept, but also in regard to the possibility that particles are first created in the solution process or that during the crystallization process, existing particles join again forming continuous material. In this case, they are called non-preformed particles they can appear and disappear. In other cases they exist all the time and are called pre-formed particles . 

In this theory, the fundamental notion is the concept of beam introduced similarly to that ft om the geometrical optics. The faces of the discontinuity will reflect all the electromagnetic beams due to the zero conductivity of the air filling the discontinuity The edge of the discontinuity will diffract the incident beam similarly to the Fresnel diffraction in optics. 

Finally the concept of fields penults clarification of the definition of the order of transitions [22]. If one considers a space of all fields (e.g. Figure A2.5.1 but not figure A2.5.3, a first-order transition occurs where there is a discontinuity in the first derivative of one of the fields with respect to anotlier (e.g. (Sp/S 7) = -S... 

Net-tension failures can be avoided or delayed by increased joint flexibility to spread the load transfer over several lines of bolts. Composite materials are generally more brittle than conventional metals, so loads are not easily redistributed around a stress concentration such as a bolt hole. Simultaneously, shear-lag effects caused by discontinuous fibers lead to difficult design problems around bolt holes. A possible solution is to put a relatively ductile composite material such as S-glass-epoxy in a strip of several times the bolt diameter in line with the bolt rows. This approach is called the softening-strip concept, and was addressed in Section 6.4. 

The principal cathodic reaction on the upper surface of the membrane is the reduction of Cu " that is formed by the reaction of Cu with dissolved oxygen in the water these Cu ions are provided partly from the diffusion through the pores in the oxide membrane from within the pit and partly from those produced by cathodic reduction (equation 1.154). Lucey s theory thus rejects the conventional large cathode small anode relationship that is invoked to explain localised attack, and this concept of an electronically conducting membrane has also been used by Evans to explain localised attack on steel due to a discontinuous film of magnetite. 

Women who become pregnant while on a dopamine agonist should discontinue treatment immediately to minimize fetal exposure. Because cabergoline has a long half-life, women who plan to become pregnant should discontinue the drug at least 1 month before planned conception. 

Patients of childbearing potential and their partners must be counseled to (1) use proper birth control while undergoing treatment for rheumatoid arthritis and (2) discontinue medications at least 3 months before conception. 

Male patients with RA must receive counseling about the effects of certain medications on their fertility and potential harm to the fetus. It is difficult to establish causality between use of a medication by a male and the effect on fertility or fetal development therefore, a conservative approach must be taken. Patients of childbearing potential and their partners must be counseled to (1) use proper birth control while undergoing treatment for RA and (2) discontinue medications at least 3 months before conception.37... 

M molar mass), where I and III are the tricritical or -regions. Here, the chain molecules exhibit an unperturbed random coil confirmation. In contrast, I and II are the critical or good solvent regimes, which are characterized by structural fluctuations in direction of an expanded coil conformation. According to the underlying concept of critical phenomena, the phase boundaries have to be considered as a continuous crossover and not as discontinuous transitions. 

Toxicities are GI (stomatitis, diarrhea, nausea, vomiting), hematologic (thrombocytopenia, leukopenia), pulmonary (fibrosis, pneumonitis), and hepatic (elevated enzymes, rare cirrhosis). Concomitant folic acid may reduce some adverse effects without loss of efficacy. Liver injury tests (aspartate aminotransferase or alanine aminotransferase) should be monitored periodically, but a liver biopsy is recommended during therapy only in patients with persistently elevated hepatic enzymes. MTX is teratogenic, and patients should use contraception and discontinue the drug if conception is planned. 

Le Maguer and Yao (1995) presented a physical model of a plant storage tissue based on its cellular structure. The mathematical equivalent of this model was solved using a finite element-based computer method and incorporated shrinkage and different boundary conditions. The concept of volume average was used to express the concentration and absolute pressure in the intracellular volume, which is discontinuous in the tissue, as a... 

It is to be noted that/(r) is normalized to unity. Due to discontinuity problem in the number of electrons [13] in atoms and molecules, the right- and left-hand side derivatives at a fixed number of electrons introduces the concepts of EF for nucleophilic and electrophilic attack, respectively. Introducing the finite difference approximation and the concept of atom condensed Fukui function (CFF) [14], the working equations are... 

This limit, which might be referred to as the ultimate tinctorial strength , reflects the maximum degree of dispersion which can be achieved in a particular vehicle system under a certain set of conditions. However, experimental results may deviate more or less from the theoretical concepts and an ideal dispersion is not normally realized not all agglomerates are broken down entirely. This, however, is of no consequence, because even the experimentally determined ultimate tinctorial strength is by no means considered a standard for industrial application technical operations are not always allowed to go to completion, and the dispersion process is often discontinued, mainly for economical reasons. 

Gryns (1896), Hedin (1897), and especially Overton (1900) looked at the permeability of a wide range of different compounds, particularly non-electrolytes, and showed that rates of penetration of solutes into erythrocytes increased with their lipid solubility. Overton correlated the rate of penetration of the solute with its partition coefficient between water and olive oil, which he took as a model for membrane composition. Some water-soluble molecules, particularly urea, entered erythrocytes faster than could be attributed to their lipid solubility—observations leading to the concept of pores, or discontinuities in the membrane which allowed water-soluble molecules to penetrate. The need to postulate the existence of pores offered the first hint of a mosaic structure for the membrane. Jacobs (1932) and Huber and Orskov (1933) put results from the early permeability studies onto a quantitative basis and concluded molecular size was a factor in the rate of solute translocation. 

From a practical point of view, the deviation from main-chain continuity is the most interesting one. Especially the concept of the so-called parallel offset of the main chain is favorized. It is realized in a commercial product made from 4-hydroxybenzoic acid and 2,6-hydroxynaphthalenecarboxylic acid. The incorporation of small amounts of 2,6-hydroxynaphthalenecarboxylic acid causes a discontinuity in the main chain but only in form of a parallel offset of some chain segments. Thus, the ability to form liquid crystalline states is largely maintained as well as the anisotropic properties of the molten and solid polyester. Instead, the melting point is significantly reduced, as desired. 

Should there be any suspicion of development of dependence, the drug should be discontinued slowly and with adequate support for the patient. Dependence, however, is an adverse reaction which has been reported for a wide range of drugs, controlled and non-controlled. In some situations, treatment needs to be continued despite the manifestation of side-effects, even dependence. For example, in cancer patients suffering from severe pain in terminal illness, opioid medication should be continued whether or not dependence is developing. The concept of risk-benefit balance must always be used in any clinical setting. The suspicion of dependence should be reported at least to the national authorities. 

Ovarian enlargement is the most common side effect of clomiphene use. The occurrence of multiple births following ovulation induction with clomiphene is 4 to 9% 90% of these multiple births are twins. Since clomiphene is teratogenic, therapy should be discontinued if there is a chance that conception has occurred. Rarely, irreversible ocular toxicities have been reported with clomiphene use. 

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