Naturally occurring objects

The contained-in policy is a special, more flexible version of the mixture and derived-from rules that applies to environmental media and debris contaminated with hazardous waste. Environmental media is the term U.S. EPA uses to describe soil, sediments, and groundwater. Debris is a term U.S. EPA uses to describe a broad category of larger manufactured and naturally occurring objects that are commonly discarded. Examples of debris include the following ... 

Large, naturally occurring objects such as tree trunks and boulders... 

Intuitively, objects such as lines, squares, and cubes possess dimensionalities of 1.0, 2.0, and 3.0, respectively. It is also rational to expect that many natural, as well as manmade, objects possess non-integral, or fractional, dimensionalities due to complicated patterns. Classical examples of common fractal patterns and forms include naturally-occurring objects such as coastlines, clouds, mountains, and snowflakes. 53-55 ... 

Stereochemistry may seem esoteric, but chirality pervades our very existence. On a molecular level, many biomolecules fundamental to life are chiral. On a macroscopic level, many naturally occurring objects possess handedness. Examples include chiral helical seashells shaped like right-handed screws, and plants such as honeysuckle that wind in a chiral left-handed helix. The human body is chiral, and hands, feet, and ears are not superimposable. 

Despite of the fact that several explosives as military grade RDX, other RDX-based materials, such as C4, Urea Nitrate (UN) and especially Semtex generate strong emissions (Fig. 7.5), they are not characteristic enough to use them for their identification emissions on the background of naturally occurring objects. The similar conclusion, that luminescence properties provide httle hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability was reached by Phifer et al. (2006). 

An abrasive is a substance used to abrade, smooth, or polish an object. If the object is soft, such as wood, then relatively soft abrasive materials may be used. Usually, however, abrasive coimotes very hard substances ranging from naturally occuring sands to the hardest material known, diamond. 

Bradshaw and his coworkers have listed several motivations for their explorations in this area. One objective of [the] research program is to prepare and study a series of multi-dentate compounds which resemble naturally occurring macrocyclic compounds . Further, Bradshaw and his coworkers have said that it is our hope that we can prepare macrocycles to mimic the selectivities of the naturally occurring cyclic antibiotics and thereby make available models for the investigation of biological cation transportation and selectivity processes . These workers have presented a number of comparisons with valinomy-cin . The other expressly stated goal of their research is to prepare molecules which will allow us to systematically examine the parameters which affect complex stability and to understand that stability in terms of AH and TAS values for complex formation . 

Since /1-lactams can be prepared via reactions of ester enolates with imines, these reactions are of great interest for synthetic and medicinal chemists. The synthesis of naturally occurring antibiotics and other physiologically active //-lactams is an objective of much current work. Though the stereocenters in those reactions are often established by addition of enolates to imines, they are discussed in Section D.1.6.1.3. In this section, only some basic results concerning //-lactams are presented. 

The overall objective of this chapter is to review the fundamental issues involved in the transport of macromolecules in hydrophilic media made of synthetic or naturally occurring uncharged polymers with nanometer-scale pore structure when an electric field is applied. The physical and chemical properties and structural features of hydrophilic polymeric materials will be considered first. Although the emphasis will be on classical polymeric gels, discussion of polymeric solutions and nonclassical gels made of, for example, un-cross-linked macromolecular units such as linear polymers and micelles will also be considered in light of recent interest in these materials for a number of applications... 

To help achieve this objective. Section III has been restricted mainly to older studies however, much of the work covered in this section is clarified or challenged by work discussed in later sections so should not be taken in isolation. The work on naturally occurring and synthetic porphyrins is included together in Section V, the older studies being discussed in the introduction to the section. 

The environment has negative effects on most metals thus, when metallic archaeological objects are eventually found, they are generally in an advanced state of decay. The decay of metals and alloys caused by the chemical action of gases and/or liquids in the environment is known as corrosion. Corrosion processes are natural destructive processes that result in the waste of most metals and alloys. The ultimate result of all corrosion processes is the reversion of most metals from the metallic condition in which they are used, to the chemically combined form in which they naturally occur in the crust of the earth. Rust, the reddish-brown corrosion product that forms on... 

Elucidation of the three-dimensional structures of / -structural fibrous proteins has attracted the interest of scientists for more than 50 years. In the early days, the objects of these studies were predominandy the naturally occurring fibrous assemblies obtained from jS-silk and stretched mammalian... 

The ambition of the OSPAR Commission, moreover, as manifested in the Objective of the Strategy aims at continuously reducing discharges, emissions and losses of hazardous substances (as defined In Annex 1) with the ultimate aim of achieving concentrations In the marine environment near background values for naturally occurring substances and close to zero for man-made synthetic substances. ... 

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