Focus considerations

Life-Support Applications. Exploration of outer space by humans has focused considerable attention on maximum as weU as minimum limits in the oxygen content of life-support atmospheres. Above the earth, both the atmospheric pressure and the partial pressure of oxygen decrease rapidly. The oxygen content of air remains constant at 20.946% to an altitude of ca 20 km, after which it decreases rapidly (1). 

The similarities and differences between methods based on the electron density, electron-pair density, and reduced density matrices have recently been reviewed [5]. This chapter is not intended as a comprehensive review, but as a focused consideration of A-representability constraints that are applicable to diagonal elements of reduced density matrices. Such constraints are useful both to researchers working with the Q-density and to researchers working with g-electron reduced density matrices, and so we shall attempt to review these constraints in a way that is accessible to both audiences. Our focus is on inequalities that arise from the Slater hull because the Slater hull provides an exhaustive list of A-representability conditions for the diagonal elements of the density matrix, Although the Slater hull constraints... 

Nevertheless, in most of the electronic tongue applications found in the literature, classification techniques like linear discriminant analysis (LDA) and partial least squares discriminant analysis (PLS-DA) have been used in place of more appropriate class-modeling methods. Moreover, in the few cases in which a class-modeling technique such as soft independent modeling of class analogy (SIMCA) is applied, attention is frequently focused only on its classification performance (e.g., correct classification rate). Use of such a restricted focus considerably underutilizes the significant characteristics of the class-modeling approach. 

Rather, look for evidence of the presence or absence of a few common functional groups with very characteristic absorptions. Start with OH, C=O, and NH groups in Figure 2.7 since a yes/no answer is usually available. A yes answer for any of these groups sharpens the focus considerably. Certainly the answer will contribute to development of a molecular formula from the mass spectrum (Chapter 1) and to an entry point for the NMR spectra (Chapters 3-6). These other spectra, in turn, will suggest further leads in the IR spectrum. 

The molecule Ceo was first observed in the mass spectrum of laser evaporated carbon by Kroto et al., who proposed the now familiar soccer ball stmcture. Subsequently, macroscopic quantities were synthesized. In the solid state, Ceo adopts a face-centered cubic (fee) stmcture, which can be considered to be based on the close packing of spheres with a radius of 5 A. Two tetrahedral sites and one octahedral site with radii 1.12 and 2.06 A are present in the stmcture. The availability of these empty sites and the electronegativity of Ceo make it a suitable host lattice for reductive intercalation by electropositive cations such as the alkah metals. The octahedral site is larger than any of the alkah cations, but the tetrahedral site is about the same size as Na+. The discovery of Superconductivity in K Ceo (Tc = 18K) has focused considerable interest on these materials. Intercalation compounds can be prepared by direct reaction of the alkali metal with Ceo to form compositions Aj,C6o (x = 2, 3, 4, or 6) depending on the specific A cation. Direct reaction of Ceo with the alkali metals is the most conveiuent route to the AeCeo phases other compositions can be prepared by use of the appropriate stoichiometry or by reaction of AeCeo with Ceo. Other alkali metal reagents such as NasHg2 and NaH have also been used. ... 

The current interest in alcohols as motor fuels is rooted in the search for alternate fuels to replace our suddenly limited petroleum-based fuels. The fact that methyl alcohol (methanol) can be produced from a variety of sources, including coal and garbage, has focused considerable attention on this material as a possible alternate fuel. The fact that the tech-... 

The earliest force fields, which attempted describe the structure and strain of small organic molecules, focused considerable attention cn more elaborate functions of the first two terms, as well as cross terms (18), repre-Kntinga "top down" philosophy. 

The development of a bedside assay for plasma BNP has focused considerable attention on the use of BNP as an aid in the diagnosis of suspected heart failure. Plasma BNP concentration is positively correlated with the degree of left ventricular dysfunction and heart failure, and this assay is now used frequently in acute care settings to assist in the differential diagnosis of dyspnea [heart failure versus asthma, chronic obstructive pulmonary disease (COPD), or infection]. Recent studies found that an elevated BNP concentration is an independent predictor of heart failure as the cause of dyspnea and that in patients with decompensated heart failure, an elevated pre-hospital discharge BNP concentration is associated with an increased risk of death or readmission. Additional research is ongoing to better characterize the role of BNP measurement in the diagnosis and treatment of heart failure. 

Limbic System Dopaminergic projections from the midbrain terminate on septal nuclei, the olfactory tubercle and basal forebrain, the amygdala, and other structures within the temporal and prefrontal cerebral lobes and the hippocampus. The DA hypothesis has focused considerable attention on the mesolimbic and mesocortical systems as possible sites where antipsychotic effects are... 

The importance of polymers in pharmaceutical technology is proved by the fact that an independent monograph written by Czetsch-Lindenwald [1] was published as long ago as 1963, summarizing the great choice of pol)maers used in pharmacy. Textbooks and manuals published in the past decades also discuss pol)nners [2-9] and focus considerable attention on polymeric and biopolymeric... 

Self-assembly is an important process in natural systems and its better understanding in model systems has focused considerable attention in recent years with synthetic chemistry producing fascinating novel supramolecular structures [32, 34-36]. Most studies of self-assembly have so far focused on purely organic and/or metal coordination systems. A contribution from the organometallic chemistry can add a new dimension to this field. 

The safety demands within the nuclear industry have accelerated studies on pressure vessel material behavior and advanced the state of the art of stress analysis. For instance, the nuclear reactor, with its extremely large heavy section cover flanges and nozzle reinforcement ojjerating under severe thermal transients in a neutron irradiation environment, has focused considerable attention on research in this area which has been directly responsible for improved materials, knowledge of their behavior in specific environments, and new stress analysis methods. 

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