Artificial or Natural

During and after the Second World War, Carson worked for the US Fish and Wildhfe Service, where she published a series of popular books on the 

This vision of the earth as a self regulating, harmonious being that takes into accoimt a balance of its inorganic and organic components was popularized in J. Lovelock (1979), which was the source of a different current of environmentalism from the one pioneered by Carson. 

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Lightfastness is measured by exposing pigmented film to an artificial or natural, eg, Florida exposure, light for a predetermined time. It is a relative term where the color of a sample exposed to a known light source is compared to its original color values. To make it meaningful, aH conditions of the exposure have to be weH defined. 

Webster TM (2005) Patch expansion of purple nutsedge (Cyperus rotundus) and yellow nutsedge (Cyperus esculentus) with and without polyethylene mulch. Weed Sci 53 839-845 White GJ, Buczacki ST (1979) Observations on suppression on clubroot by artificial or natural heating of soil. Trans Br Mycol Soc 73 271-275... 

Meta-analysis of 48 tests, where induction of phenolic compounds after artificial or natural wounding was measured, revealed a marginally significant, positive mean effect size (Fig. 3.2a). Positive effect sizes indicate larger concentrations of phenolics in the wounded algae, i.e., induction of phenolics. The mean effect sizes... 

Radioactive isotopes can be classified as being either artificial or natural. Only the latter are of interest in geology, because they are the basis for radiometric dating... 

As for the cultivation of other types of marine microorganisms, e.g., those with a specific potential for the production of biologically active metabolites, predominantly small-scale experiments (shake flasks) have been described. Alternatively, artificial seawater or 25 50 75 90% natural seawater has served as a basis for nutrient media. The concentrations of carbon and nitrogen sources reached up to 2 % (w/w) starch, glucose, molasses, glycerol, soybean oil, yeast extract, malt extract, beef extract, peptone, cornsteep liquor and NZ-amine. In the absence of artificial or natural seawater, high concentrations of... 

Pressure or vacuums may be applied to filtering systems to hasten the removal of contaminants. Other systems only use gravity, which involves percolating contaminated water through artificial beds or columns containing sand and other materials. In the field, artificial or natural sediment layers routinely filter water as it migrates into the subsurface (Jekel, 1994, 129). Although many filtration systems will not remove dissolved arsenic, filters can physically remove iron (oxy)(hydr)oxides and other particles that coprecipitate and sorb arsenic. 

One may rightfully raise the question as to why some products of nuclear reactions are radioactive while others are not. The answer concerns the stability of atomic nuclei. Essentially, any radioactive element, whether artificial or natural, can be considered abnormal. A nucleus that undergoes radioactive decay is in an unstable condition, and the process of decay always leads to stable isotopes. This tendency toward the achievement of stability is illustrated by the stepwise decay of naturally radioactive uranium to form a stable isotope of lead and the formation of stable carbon by the decay of artificial radioactive nitrogen. Although the conditions resulting in the instability of atomic nuclei are fairly well understood, further consideration of these factors is beyond the scope of this discussion. 

In cellular infiltration of artificial or natural 3D scaffolds, the cells have to overcome the biophysical resistance given by the surrounding microenvironment. How to evenly distribute cells into such scaffolds while still maintaining or controlling the cell phenotype turns out to be a challenging task. 

This is the fundamental rule of the primary type of explosion protection the existence of hazardous fuel-air mixtures shall be prevented by an artificial or natural ventilation of plant installations and/or an equivalent tightness of manufacturing equipment. 

We have seen that all artificial or natural chemical compounds, whether mineral or organic, must be divided into two great classes non-asymmetric compounds with superposable image and asymmetric compounds with non-superposable image. 

Flavoring agents may be classified as natural, artificial, or natural and artificial (N A) by combining the allnatural and synthetic fiavors. Pharmaceutical flavors are available as liquids (e.g., essential oils, fluid extracts, tinctures, and distillates), solids (e.g., spray-dried, crystalline vanillin, freeze-dried cinnamon powders, and dried lemon fluid extract), and pastes (e.g., soft extracts, resins, and so-called concretes, which are brittle on the outside and soft on the inside). Liquid flavors are by far the most widely used because they diffuse readily into the substrate. They are available both as oily (e.g., essential oils) or non-oily liquids. Their texture is generally dependent on the solvent within which they are prepared. Fluid extracts may contain a single ingredient or a variety of compounded ingredients. Tinctures are obtained by maceration or percolation of specific herbs and spices in alcohol. 

Many reviews and books on the immobilization of enzymes have been published during the last two decades [5, 11-20]. The intent of this part of the review is to explain the basic principles and to show recent developments of enzyme immobilization for the purpose of preparative biotransformation. The attachment of enzymes onto prefabricated artificial or natural carriers will be given special emphasis (see Sect. 3.2). 

Controlled-release products typically employ one or more polymeric excipients to control drug release. Such polymers include artificial or natural... 

For oils of a similar type, ultraviolet (UV) absorptivity is a good indicator of the resistance of an oil to discoloration under exposure to artificial or natural light. Oils with low absorptivity at 260 nm have been found to impart good color stability to light-colored rubber compounds (ASTM D-2008). 

The Weltanschauung of the Modem Age proceeds from the concq )t of opposing. .nature" and, nan . The roots of this view originate from the Descartes notion of nature, who contrasted res cogitance and res extensa (Hosle, 1991). The industrial revolution made deeper a rift natural-artificial or nature versus. .technology". A cliche evolved about human activity as about something. .unnatural". 

Among the environmental factors that influence the persistence of the carbamate insecticides in the aquatic environment is the decomposing of these compounds when influenced by solar radiations. Many organi-cides undergo changes after they are exposed to ultraviolet light (uv) and artificial or natural sunlight (7, 8, 9, 10). Therefore, the effect of... 

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