Temporary States Research Articles

Electron attachment to CO2 clusters

Vertical and adiabatic electron attachment to carbon dioxide clusters (CO2)N (N=2–5) is studied at high ab initio levels of theory. As a first step the geometries of neutral and anionic CO2 clusters are reexamined. The potential energy surfaces of both neutral and anionic CO2 clusters show many minima, and several isomers have been reported so far. Here we present new lowest-energy isomers for the tetramer and pentamer anion clusters, as well as high-level results for relative and CO2 evaporation energies. Electron correlation is crucial for the computed properties, and since we had to make certain compromises about the theoretical level in order to include larger clusters, a thorough investigation of different ab initio methods is performed for the dimer. The vertical affinities of the investigated (CO2)N clusters are found to be clearly negative; i.e., vertical attachment into valence orbitals leads to temporary anion states. The energies of these resonances as well as the associated autodetachment lifetimes are computed using complex absorbing potentials at the frozen-orbital and correlated second-order Green’s function levels. Whereas the cluster environment has a surprisingly weak influence on the negative vertical affinities, solvation has a strong effect on the adiabatic electron affinities. The computed trends suggest that the tetramer is at the brink of stability and that the pentamer cluster is the smallest species possessing an appreciable positive electron affinity. Our findings have profound implications for the interpretation of the low-energy electron attachment experiments and provide a basis for the discussion and modeling the attachment process.

Assessment of anxiety in women undergoing in vitro fertilization (IVF) by the state-trait anxiety inventory (STAI)

Objective: The STAI is one of the most reliable instruments for measuring anxiety in adults and it can differentiate between temporary and long-standing states. Since infertility and treatments such as IVF cause a great deal of anxiety, it would be of particular importance to evaluate its applicability as STAI is an easy inventory that takes approximately 10 min for its administration and there is no standard tests being used.

Crisis, what crisis? Marketing, Midas, and the Croesus of representation

A crisis, according to the Oxford English Dictionary, is “a decisive moment”, “a turning point”, “a time of great difficulty”. If this is the case, then marketing cannot possibly be in crisis. Crises are temporary states of heightened anxiety, whereas marketing is in a semi‐permanent philosophical pickle. Or so scholarly commentators would have us believe. This paper argues that there is no crisis of representation in marketing. There are more, and more varied, representations of marketing than there have ever been. Representationally speaking, marketing is living in a golden age, a time of Croesus and King Midas. The real problem is that many of these representations are not very good, albeit for understandable reasons. We need to raise the quality rather than increase the quantity of our “experimental” endeavours and this paper makes five recommendations to that end.

Mechanism for Anion and Sulfur-Radical Production by 1−18 eV Electron Impact on Dimethyl Disulfide Adsorbed on Ice

We report the 1−18 eV electron-stimulated desorption of the anions H-, S-, CH3-, and (SCH3)- from dimethyl disulfide (CH3SSCH3) condensed on amorphous D2O films physisorbed on Pt. Below 11 eV, the desorbed anions and their respective sulfur-radical counterparts (CH2SSCH3)•, (CH3SCH3), (SSCH3)•, and (SCH3)• are formed via dissociative electron attachment to CH3SSCH3 (i.e., from the formation and subsequent dissociation of temporary states of CH3SSCH3-). At 4.5, 6.0, and 9.0 eV incident electron energies, different dissociative attachment channels compete for the production of these reactive species. Above 11 eV, the same anions are produced via dipolar dissociation with corresponding cation fragments. A negative species observed at 35 amu is attributed to the formation of long-lived or stable (SHD)- anions, produced via secondary reactions on the ice film. Anion desorption is shown to be enhanced by the presence of the water substrate.

On the Molecular and Electronic Structure of Spiroketones and Half-Molecule Models

The equilibrium structures of three polyketones based on the 2,2‘-spirobiindan skeleton (1,1‘-dione, 1,3,1‘-trione, and 1,3,1‘,3‘-tetraone), their “half-molecule” fragments (1-indanone and 2,2-dimethylindan-1,3-dione), and the indandione dimer (2,2‘-dimethyl-[2,2‘]-biindenyl-1,3,1‘,3‘-tetraone) were investigated using the density functional theory model B3LYP/6-31G(d,p). The results matched the X-ray experimental data that are available for one of the spiroketones. The electronic structure of these ketones was investigated by means of their spectroscopic properties. The NMR 13C chemical shifts, calculated by the continuous-set-of-gauge-transformations formalism with the B3LYP/6-311+G(2d,p) method, were fairly consistent with NMR observations, in particular for the carbonyl, spiro, and quaternary carbons. The He(I) photoelectron spectra were measured and interpreted by means of ab initio outer-valence-Green's-function calculations. The theoretical results consistently reproduced the energies and splittings of the uppermost bands. These bands were associated with the phenyl π orbitals and the n(CO) lone-pair orbitals of the keto groups. Electron transmission spectroscopy, with the support of calculated π* virtual orbital energies, was employed to characterize the empty levels. Strong mixing between the phenyl and carbonyl π* fragment orbitals gave rise to stable anion states. Temporary anion states with mainly carbonyl character were observed in the 1.5−2.5 eV energy range. In the spiroketones, their energy splittings increase with the number of carbonyl groups present in the molecules and indicate the occurrence of through-space interactions between the two perpendicular indan halves.

Loss of Submerged Macrophytes in Shallow Lakes in North-Eastern Germany

During the 1950s, the submerged vegetation of shallow lakes in north-eastern Germany was dominated by nutrient tolerant species, with Ceratophyllum demersum and Myriophyllum sp. being most common. Almost one third of 300 investigated lakes had already lost their submerged macrophytes at that time. Very shallow lakes showed either high or low macrophyte abundance. Increasing depth resulted in medium macrophyte abundances, which may contribute to the stabilisation of local or temporary clearwater states. Forty years later, the percentage of lakes without macrophytes had dramatically increased. Between 55 and 85% of the investigated lakes showed a low abundance. The decline was most pronounced in very shallow lakes. The majority of the investigated lakes showed summer TP concentrations below 100 μg L–1, but no colonisation by submerged macrophytes, which indicates a resilience against re-colonisation.

Influences of Current Mood and Noise Sensitivity on Judgments of Noise Annoyance

Noise annoyance is one of the most studied reactions to auditory events. Previous research has demonstrated that annoyance reactions may be mediated by individual characteristics such as personality, attitudes, and noise sensitivity (traits). Transient temporary states such as an individual's current mood have been studied to a lesser extent. The author studied annoyance reactions to an everyday noise in participants who either were slightly annoyed or in a neutral affective state. The results showed that current mood had an overall effect on judgments of annoyance and on a participant's preference for sound. In addition, a participant's current mood interacted with noise sensitivity. These results indicate that both individual noise sensitivity (traits) and transient moods (states) are important for human auditory perception and evaluation.

The influence of depressive state features on trait measurement

Background: Certain personality characteristics may change during depression, reflecting temporary states, while others remain stable. This study investigates the stability of personality during depression. Identification of depression-sensitive personality traits may help to elucidate the mechanisms that influence course and outcome of depression. Methods: For 42 ambulatory and 38 day care patients with a depressive disorder, depression severity and personality characteristics were measured repeatedly during a 12 week-period. The total HDRS score was indicative of depression severity, while the NEO-FFI was used for measurement of basic personality traits and the IPS for depression-specific traits. Results: In 12 weeks, depression severity significantly decreased for both patient groups. The Big Five traits Neuroticism and Extraversion and all but one aspect of Interpersonal sensitivity showed depression-related changes towards the normal range. Openness, Altruism and Conscientiousness remained stable. Limitations: The number of patients excluded from the study due to missing data is substantial. Furthermore, it was not possible to control for treatment influence due to a double-blind design. Conclusions: Neuroticism, Extraversion and Interpersonal sensitivity scores are likely to reflect state components during a depression, while the stability of Openness, Conscientiousness and Altruism scores indicates pure personality traits.

Temporary anion states of selected amino acids

Vertical attachment energies for the formation of low-lying temporary anion states of glycine, alanine, phenylalanine, tryptophan, and proline in the gas phase are reported using electron transmission spectroscopy. Electron attachment into the empty π* orbital of the –COOH group was observed in all the compounds. Temporary anion states associated with the side groups in phenylalanine and tryptophan are found to be stabilized with respect to those in the reference compounds toluene and indole, respectively, by approximately 0.2 eV. We attribute this to electrostatic effects and explore, using simple theoretical models, the extent to which such anion states could be further stabilized if these amino acids were in zwitterionic form.

An Integral Psychology Response to Helminiak's (2001) “Treating Spiritual Issues in Secular Psychotherapy”

This article is a response to D. A. Helminiak's (2001) “Treating Spiritual Issues in Secular Psychotherapy” from the perspective of K. Wilber's integral psychology. The article consists of 3 sections: (a) a selective summary of integral psychology, including the perennial philosophy, 10 levels of development, lines of development, temporary states, types of orientations, the self, and the 4 quadrants; (b) various conceptual issues; and (c) usefulness to mental health practitioners (MHPs). Although D. A. Helminiak's endeavor to formulate a clear and functional definition of spirituality is commended, his claim of novelty is shown to be unwarranted. It is argued that K. Wilber's integral model is more comprehensive, clear, coherent, and helpful to MHPs.

Very low energy electron scattering in nitromethane, nitroethane, and nitrobenzene

Absolute total integral and total backward scattering cross sections are reported for CH 3 NO 2 , C 2 H 5 NO 2 , and C 6 H 5 NO 2 at electron-impact energies from 30 meV to several eV, with some additional data at higher energies. These experimental data extend the range of species studied in low-energy electron scattering to include target molecules with dipole moments large enough to support dipole-bound states. Data provide a further test of the validity of the Born point-dipole approximation for the calculation of rotationally inelastic scattering cross sections for polar molecules, which are of importance in modeling the chemical and physical characteristics of industrial and natural plasmas. For CH 3 NO 2 and C 2 H 5 NO 2 , large cross sections are found, monotonically increasing with decreasing electron energy in qualitative and to some degree quantitative agreement with theory based on the Born model. As in earlier studies other polar species, the Born model is found to underestimate significantly backward-scattering cross sections. C 6 H 5 NO 2 shows a powerful dip in the total integral scattering cross sections <200 meV, a feature not found in the backward-scattering cross section and totally at variance with any simple theory. The suggestion is made that this behavior, in common with ClO 2 and Cl 2 O, may arise through interference between direct Born-type rotational excitation and an indirect channel involving temporary negative ion states in the continuum.

Dissociative electron attachment in chlorofluoromethanes and the correlation with vertical attachment energies

The total dissociative electron attachment (DEA) cross sections of the chlorofluoromethanes are determined in an electron beam experiment and correlated with the vertical attachment energies (VAEs) for formation of the lowest temporary anion states of these compounds. The latter are determined independently by electron transmission spectroscopy and correspond to the energies of the anions at the equilibrium geometries of the neutral molecules. As we observed previously in the chloroalkanes, the peak DEA cross sections are well correlated with VAEs. For values of VAEs between 0.9 to 3.0 eV, the peak DEA cross sections vary by more than four orders of magnitude. This is attributable in part to the remarkably monotonic variation of the temporary anion widths, arising from their finite lifetimes, over this range of VAE.

A study of the molecular structure and spectroscopic properties of polycyclic polyaza-compounds with diamond-lattice conformations

The equilibrium structures of a selection of polycyclic polyaza-compounds, characterized by diamond-lattice arrangements and conformational flexibility, were investigated with the density functional method B3LYP/6-31G(d,p). The 10- or 12-membered central ring in two tricyclic tetraaza-compounds, formally derived from tricyclo-hexadecane and tricyclo-octadecane, respectively, prefers a “square” geometry. The 16- or 24-membered central ring in nonacyclic octaaza-compounds, related to pentacyclo-octacosane, and in nonacyclic dodecaaza- and hexadecaaza-compounds, both related to nonacyclo-tetratetracontane, can instead adopt two or three alternative conformations with “square” or “rectangular” geometry. The theoretical structural models are consistent with evidence from NMR and X-ray spectroscopy. In addition, they provide a satisfactory account of the 13C NMR chemical shifts, which were predicted with a continuous set of gauge transformation calculations performed with the B3LYP/6-311+G(2d,p) formalism. The electronic structure was also studied by means of ab initio outer valence Green function calculations, which give a consistent, overall description of the different manifolds of photoionizations, associated with the nitrogen lone pair orbitals. Electron transmission spectroscopy was employed to detect the low-lying temporary anion states of some representative compounds. © 2001 John Wiley & Sons, Inc. Int J Quant Chem, 2001

FCN- and FNC- radical anions

The radical anions FCN− and FNC− are studied at high ab initio levels of theory. Both anionic isomers possess a weak so-called three-electron bond, and highly correlated methods are necessary to predict their geometric parameters. At their respective equilibrium structures both anions represent electronically stable species but the associated neutrals FCN and FNC exhibit negative vertical electron affinities. Our computed electron affinities show that both anionic isomers are stable with respect to adiabatic electron loss. FCN− represents the global minimum of the FCN-plus-electron system, and FNC− can decay only ia rearrangement and simultaneous autodetachment, but is predicted to exhibit a very long lifetime. The temporary anion states associated with vertical electron attachment to the neutrals are investigated within the framework of the complex absorbing potential method. Short-lived 2Π resonance states are identified and predicted to be observable in an electron transmission experiment. In spite of their close relation, the two isomeric anions FCN− and FNC− show surprisingly different properties. FNC− can be characterised as a typical pseudo-dihalogen anion, whereas FCN− is more similar to the isovalent CO2−.

Feasibility and Validity of the VAS and TTO for Eliciting General Population Values for Temporary Health States: A Comparative Study

General population preferences for standardized health states are usually obtained for chronic health states. The primary objective of this study was to analyze the feasibility and validity of using time trade-off (TTO) and a visual analog scale (VAS) to elicit preference values for temporary health states (THS=1 year duration, followed by normal health). Subjects were a random sample (n=300) of the general population. 43 health states generated by the EuroQo-5D were valued. The VAS proved slightly more feasible than the TTO. At aggregate level, correlations between VAS and TTO values were high (Spearman r=0.98), and VAS ratings had slightly greater internal consistency and agreement with rank order preferences than the TTO. TTO values were higher than VAS values, and compression of TTO values suggested substantial reluctance to trade. The effect of age on values was reversed between methods, with older respondents scoring higher on the VAS and lower on the TTO, than other age groups. In conclusion, although the VAS proved to be slightly more feasible than the TTO, with slightly greater empirical validity, further research using a wider range of methods to test validity is required before a definitive conclusion on the relative empirical validity of the two valuation techniques can be drawn.

A Study of Surface Water Quality in Macedonia, Greece: Speciation of Nitrogen and Phosphorus

A 2-yr (1997–1998) survey aiming at the establishment of national data bases concerning the quality of surface waters has been conducted in the major river systems of Macedonia, N. Greece. This paper presents the physicochemical parameters(pH, conductivity, total suspended solids, temperature and DO),the organic pollution parameters (BOD5, COD) and the major N and P species (NO3-, NO2-,NH4+,organic N, orthophosphates and total P) determined at 25 sampling sites located on main rivers, tributaries, streams andditches that drain the major rural, agricultural, urban and industrial areas of N. Greece. Use of multivariate statistics is also made to identify the principal factors which influencethe chemistry of the water in individual river systems.The eutrophication status of the examined systems was evaluatedby means of N/P ratios. Mean N/P ratios showed large variationsamong sampling sites ranging from potential N- to P-limitationconditions. N/P ratios at particular sampling sites showed also great temporal variability thus suggesting temporary states of N- or P- limitation. Most frequently, highest ratio values wereobserved during winter and early spring. Comparisons are made between data from this study region and literature on rivers elsewhere.

Ab Initio Investigation of the Temporary Anion States of Perfluoroethane

The stabilization method is used to characterize the temporary anion states of C2F6. Based on the theoretical results, we assign the lowest-energy feature in the electron transmission spectrum of C2F6 to the 2Eu ground-state anion and the second feature to overlapping 12Au, 12A1g, 22Au, and 12Eg anion states. It is also proposed that the bimodal kinetic energy distribution of the F- ions produced in the dissociative attachment of near 5 eV electrons on C2F6 is due to the Jahn−Teller effect.

Low-energy electron attachment to fused 1,4-cyclohexadiene rings by means of electron transmission spectroscopy and exponent stabilization calculations

Electron transmission spectroscopy is used for determining the energies of vertical electron attachment to the empty π* orbitals of ethene (1), 1,4-cyclohexadiene (2), 1,4,5,8-tetrahydronaphthalene (3), and 1,4,5,8,9,10-hexahydroanthracene (4), where the number of ethene double bonds, which interact through space and through the CH2 bridges, increases along the series. In contrast with the expectations based on a simple perturbational model, the energy of the first anion state is nearly constant on going from 1 to 4. Moreover, the energy splitting between the lowest and the highest anion states in the larger molecular systems 3 and 4 is smaller than in 1,4-cyclohexadiene. The experimental data are compared with the empty orbital energies of the neutral states supplied by HF calculations using both a standard basis set and one augmented with diffuse functions, using the exponent stabilization method for distinguishing the virtual orbitals which give rise to temporary anion states. The graphs of virtual orbital eigenvalues versus the exponent scaling factor display avoided crossings and regions where the π* molecular orbital energies are relatively stable. The orbital energies determined in correspondence with the avoided crossings do not reproduce the trends of the resonances observed in the spectra. A better match with experiment (although not completely satisfactory) is obtained by determining the energies in the region of stability of the graphs. This set of results also predicts smaller through-space and through-bond interactions.

Total cross sections for dissociative electron attachment in dichloroalkanes and selected polychloroalkanes: The correlation with vertical attachment energies

Electron attachment into the lowest unoccupied molecular orbital of a typical polychloroalkane in the gas phase forms a temporary negative ion in which the impinging electron resides on a combination of local C–Cl σ* orbitals. Because of the antibonding character of these orbitals, these anions may dissociate, producing Cl− with cross sections that vary enormously over the chloroalkane family. In this work, we present absolute total dissociative electron attachment (DEA) cross sections for 33 of these compounds, and we show that the peak values of the cross sections correlate strongly with the vertical attachment energies (VAEs) for formation of the lowest anion states at the equilibrium geometries of the neutral molecules. This behavior is a consequence of the remarkably monotonic dependence of the resonance widths of the temporary anion states on VAE over the range 0.42&amp;lt;VAE&amp;lt;3.45 eV. Finally, we note also the strong connection between the s-wave attachment process at 0 eV in these compounds and the VAEs associated with the nearby anion states.

Temporary Anion States of Dichloroalkanes and Selected Polychloroalkanes

The electron attachment energies associated with the short-lived occupation of the C−Cl σ* orbitals of dichloroalkanes and selected polychloroalkanes are measured in the gas phase using electron transmission spectroscopy and compared with those observed previously in monochloroalkanes. In the dichloroalkanes, evidence for two well-resolved anion states is found only in the compounds with both chlorines on the same carbon atom. The effects of methyl substitution on chlorine-bearing carbon atoms are examined in detail and are observed to stabilize temporary anion states lying above ∼1.5 eV but to destabilize those lying below. The spread in energy of the anion states, attributable to their finite lifetimes, is examined as a function of the vertical attachment energies (VAEs) of the anions and found to vary as VAE1.5, consistent with the relationship expected on theoretical grounds for the monochloroalkanes. Calculated energies of the lowest unoccupied molecular orbitals (LUMOs) are also presented and compar...