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Single harmonic Fourier amplitude and phase (FA/P) analyses of 129 radionuclide angiographic (RNA) studies were found to reflect accurately the sequence and quantity of perfusion determined in the independently interpreted RNA studies. In addition, the anatomic detailing in peripheral studies (hands, feet, etc.) was considered superior to that obtained in RNA studies.

High resolution measurements of the two components of the ν2 (umbrella) fundamental mode of the fully deuterated oxonium ion (D3O+) are reported. The spectra were obtained by diode laser absorption in a plasma containing D2 and D2O. Analysis of the observed spectra yields precise estimates of the two band origins and molecular parameters describing the states involved. By combining these data with the available high resolution data for H3O+, using the nonrigid invertor Hamiltonian, we are able to determine the equilibrium structure and the vibrational potential function; also we predict the inversion spectrum of D3O+ and the 2v2–v2 hot band spectra of H3O+ and D3O+.

In the vinyl cation C 2 H 3 + it is believed that there is a low barrier hindering the rotation of the three protons around the CC core, with the molecule remaining planar during this internal rotation. In this paper the semirigid bender formalism is adapted to calculate the rotation and internal-rotation energy levels of this species. Numerical results are presented for a variety of different hindering potentials. The symmetries of the levels, the nuclear spin statistical weights, and the selection rules for allowed electric dipole transitions are all determined.

In this paper we report a theoretical calculation of vibration-rotation transition wavenumbers and transition moments for HD + , HT + , and DT + for v , N ≤ 5. The results for HD + agree with the experimental results to within 0.015 cm −1 .

Within the Born-Oppenheimer approximation homopolar isotopically unsymmetric diatomic ions (HD+, 14N15N+, 35Cl37Cl+, etc.) have D∞h symmetry and a non-vanishing dipole moment. This apparent paradox is reconciled here by treating carefully the transformation properties of the dipole moment operator in the D∞h group.

An effective vibration-rotation hamiltonian for the ground electronic state of a diatomic molecule is derived. The contact transformation used to account for the effect of the excited electronic states is complicated by the parametric dependence of the zeroth-order electronic energies on the internuclear distance. The effective vibration-rotation hamiltonian contains an effective internuclear potential and two effective reduced masses, one for the vibrational and one for the rotational kinetic energies. Although the method is applied to 1Σ diatomic molecules it can readily be extended to other states and polyatomic molecules.

Rotation-vibration energy levels of the isomers CCN+ and CNC+ have been determined in the following way: A large number of points in the minimum region of the 1Σ+ electronic ground state surfaces of the two ions have been computed by single reference state complete single and double excitations configuration interaction (CI-SD) calculations using canonical SCF orbitals as a molecular orbital basis. The effect of certain higher excitations has also been taken into account by using the Davidson estimate (CI-SDQ). A force constant expansion has been fitted by least squares to the ab initio points, and the resulting potential expression has been used to calculate rotational and vibrational constants using the perturbation theory expressions. In order to assess the reliability of these calculations and, in particular, the flexibility of the Gaussian basis sets used, identical calculations have been performed for the isoelectronic C3 radical. For C3 the rotational and vibrational energy levels obtained by the perturbational approach are compared to those calculated using the nonrigid bender Hamiltonian. The nonrigid bender results at the CI-SDQ level are found to be in good agreement with the available experimental data. From these CI-SDQ calculations the equilibrium structure of the ground state of C3 is obtained as bent (αe = 162°, r e = 1.290 A ). Dipole moment functions and vibrational transition moments have also been calculated for all three molecules. The transition moment for the ν3 fundamental of C3 is found to be very large (0.44 Debye).

We have calculated 64 points on the ground electronic state potential energy surface of the silyl radical (SiH 3 ) using the MRD CI technique. This potential surface gives an inversion barrier of 1951 cm −1 and an equilibrium geometry of r e = 1.480 A and α e (HSiH) = 111.2°. Using the non-rigid invertor Hamiltonian with this potential we determine for SiH 3 that ν 1 = 2424 cm −1 , ν 2 = 778 cm −1 , ν 3 = 2106 cm −1 , and ν 4 = 976 cm −1 ; the inversion splitting is calculated to be 0.11 cm −1 . Rotational constants and centrifugal distortion constants have also been calculated.

Thirteen pure rotational transitions of CH2 in its X 3B1 ground vibronic state have been measured and assigned using the technique of far‐infrared laser magnetic resonance (LMR) spectroscopy. The energy levels thus determined led to the prediction and subsequent detection by microwave spectroscopy of a further rotational transition 404–313, at lower frequency (∼70 GHz). The analysis of these observations yields precise rotational constants as well as spin–spin, spin‐rotation, and hyperfine interaction parameters for gas phase CH2. Its rotational spectrum may enable interstellar CH2 to be detected by radio astronomy. Two rotaional transitions within the v1=1 excited vibrational state have also been identified in the LMR spectrum. Future observations of vibrationally excited CH2 may afford a means of determining the singlet–triplet splitting in methylene, and studies of CD2 and CHD will result in improved structural determinations.

Evaluation is often both conceptually and functionally separate from program planning and operations management. Though program managers may not see themselves as served well by the work of evaluation staffs, there are a number of potentially beneficial side effects to be realized from close collaboration between program administrators and evaluators. These flow only when the evaluation task is broadly defined and when both administrators and evaluators recognize their interdependence. Particular functional benefits to management from evaluation are described. Characteristics of interorganizational relations which might increase the probability of their attainment are then outlined and discussed.

The semirigid invertor Hamiltonian and computer program that we developed [see Jensen and Bunker, J. Mol. Spectrosc. in press] is used to calculate the rotation and out-of-plane bending energy levels of thioformaldehyde (H 2 CS) in the A 1 A 2 and a 3 A 2 electronic states. By fitting to the experimental data it is found that the equilibrium structure of the A 1 A 2 state is planar and that the a 3 A 2 state has a barrier to planarity of only 7 cm −1 . This is markedly different from the situation in formaldehyde, which has a much higher barrier in both of the corresponding electronic states. However, in both molecules the triplet state has the higher barrier.

A Xe-133 hepatic study was misleading when the absence of Xe-133 localization in an area of low CT numbers was considered to be negative for a diagnosis of focal fatty infiltration.

We have observed and assigned a number of far infrared laser magnetic resonance spectra of CH2 arising from rotational transitions within the lowest vibrational state of the a 1A1 electronic excited state and from transitions between such singlet levels and vibrationally excited levels of the X 3B1 electronic ground state. The singlet–singlet transitions are magnetically active, and the singlet–triplet transitions have electric dipole intensity because of the spin‐orbit mixing of singlet levels with vibrationally excited levels of the triplet state. By identifying four pairs of singlet and triplet levels that perturb each other we can accurately position the singlet and triplet state relative to each other and determine the single–triplet energy splitting. We determine that T0(a 1A1)=3165±20 cm−1 (9.05±0.06 kcal/mol; 0.392±0.003 eV), and Te(a 1A1)=2994±30 cm−1 (8.56±0.09 kcal/mol; 0.371±0.004 eV). A new ab initio calculation of the spin‐orbit matrix element between these two states has been of assistance in assigning the levels that perturb each other and has enabled us to calculate the radiative lifetimes of the lowest ortho and para levels of the a 1A1 state to be about 18 s in each case.

Atherosclerosis is the most common cause of arterial occlusive disease of the lower extremity, but symptoms of claudication or nest pain in a patient under 50 years of age should lead to consideration of nonathenosclerotic etiolo gies. Atkins and Key [11in 1947 first described myxomatous accumulations in the adventitia of an external iliac artery. Ejrup and Hiertonn [2] described this condition in the pop liteal artery in 1954; Flanigan et al. [3] in 1979 published an extensive summary of 115 accumulated cases of cystic advential disease since that time. Because of the limited emphasis of this entity and its characteristic radiographic features in the radiologic litena ture [4—6] we report two cases that demonstrate typical and atypical features of cystic adventitial disease, with sono graphic and radiographic evaluation of an injected surgical specimen demonstrating the unique morphologic character istics of this lesion.

A three-dimensional fit of ab initio MRD CI potential data has been made for the lowest two electronic states of the HNC1 molecule (X 2A″ and A 2A'), and the corresponding vibrational frequencies and rotational energies have been computed using the non-rigid bender Hamiltonian. For the ground state the vibrational frequencies obtained are ν1 = 2942 cm−1, ν2 = 1232 cm−1, and ν3 = 549 cm−1, while the corresponding values for the first excited state are 3524,947 and 836 cm−1 respectively. We calculate Tc(A 2A') 16200 cm−1, To(A2A') = 16400 cm−1, and the Franck-Condon maximum, A(0,3,1)-X(0,0.0), is calculate at 19200 cm−1(5200 A).

In recent years, several grain and oilseed producer cooperatives have expanded operations in international marketing. Some of these expansions include the purchase of part of Alfred C. Toepfer Co., an international commodity trading company, by several North American and European cooperatives; the expansion of Japanese cooperatives into U.S. grainhandling and storage functions; integration of Italian cooperatives into processing industries in developing countries; and the enlargement of one interregional cooperative into the fourth largest U.S. grain exporter. We suggest that these innovations are preliminary signals of a structural change in international grain trade. Our objective is to examine the changing role of farmer cooperatives in the complex international arena of grain and oilseed trade. Four phenomena are explored: (a) farmer cooperative location in the world soybean, coarse grain, and wheat market structure; (b) market share trends of U.S. cooperatives at the local, regional, and export levels; (c) the increasing importance of foreign cooperatives in the international grain trade; and (d) factors that might constrain or enhance the growth of cooperatives in the world grain trade.

Ab initio values of ν1, ν3 and the zero point energy for triplet methylene (X 3B1 CH2) have been calculated. Complete second order configuration interaction calculations for the six valence electrons, with a Davidson‐type unlinked cluster correction, were done at 37 selected nuclear geometries. We have fitted an analytic potential through these points and used the nonrigid bender Hamiltonian, and a variational procedure, to calculate the rotation–vibration energies. We have obtained ν1=2985±20 cm−1, ν3=3205±20 cm−1, and the zero point energy as 3710±20 cm−1. The uncertainties represent our best estimate of the full uncertainties in the calculations. From the experimental data for singlet methylene (a 1A1) we have determined the zero point energy of that state to be 3620±20 cm−1. Combining these two zero point energies with the experimental value of T0(a 1A1)=3156±5 cm−1 [Bunker et al. J. Chem. Phys. 85, 3724 (1986)] we obtain the vibrationless singlet–triplet splitting Te(a 1A1) =3246±30 cm−1 (9.28±0....

The equilibrium bond length and the shape of the complete potential energy curve for the methyl radical CH3 are determined. This is done by fitting the experimental data [mainly from C. Yamada, E. Hirota, and K. Kawaguchi, J. Chem. Phys. 75, 5256–5264 (1981)] using the nonrigid invertor Hamiltonian and a model anharmonic potential function. As a result the v2 (out-of-plane bending) dependence of the rotational constants is explained and the v2 dependence of the spin-rotation coupling constants is modeled. In addition, some of the vibrational energies and rotational, centrifugal distortion, and spin-rotation constants are predicted for the 13CH3, 12CD3, and 12CT3 isotopes.

We report the detection of 17 pure rotation transitions in the ground vibronic state of the CD2 radical using far infrared laser magnetic resonance spectroscopy. Fitting the data using an effective rotational Hamiltonian yields values for the three rotational constants, seven centrifugal distortion constants, the three electronic spin‐rotation, and two electronic spin–spin parameters. We also fit this data, and CD2 ν2 band data (published separately), using the semirigid bender Hamiltonian and obtain the effective bending potential function for CD2. Combining this with previous CH2 results enables us to predict the rotation bending energy levels of CHD. We also report here the detection of two further rotational transitions in the ν1 excited vibrational state of CH2.

The double group of the molecular symmetry group of ferrocene is used to classify the rotational and torsional wavefunctions and the ‘approximate normal coordinates’ of the molecule. The approximate normal coordinates do not depend on either the torsional angle or the torsional quantum number, and from their symmetry species the infra-red and Raman selection rules are determined. It is also shown how an ultra-high resolution analysis of some of the infra-red bands might yield the height of the torsional barrier.

In 1964 Duncan determined force fields for the molecules CH3—C≡C—CH3 and CH3—C≡C—SiH3 under the assumption that the force constants were not dependent on the torsional angle γ. In the first half of this paper we determine the quantitative effect of adding various γ-dependent force constants to Duncan's force field for CH3—C≡C—CH3. The results lead to complications concerning the symmetry species of the normal coordinates, the magnitude of the Coriolis coupling constants, and the calculation of the energy levels. The possible avoidance of these complications is discussed.In the second half of the paper a formalism is set up relating the rotational and torsional centrifugal distortion constants to the vibrational force field for certain molecules with nearly free internal rotation. Duncan's force field for CH3—C≡C—SiH3 is used to calculate some centrifugal distortion constants for that molecule and for CH3—C≡C—SiD3 on the assumption of completely free internal rotation. Good agreement is obtained between the quantities calculated here and the observed quantities determined by Kirchhoff and Lide.

The extant theory concerning the interpretation of the infrared and Raman spectrum of dimethylacetylene is summarized. This theory is extended and the symmetry group, symmetry coordinates, and the symmetry properties of the normal coordinates are all discussed. The usual G matrix theory and FG matrix method for the determination of force constants and normal coordinates has to be modified and the G matrix most useful for the calculations is derived. Detailed expressions are obtained for the energy levels of the first excited state of each of the normal vibrations; it is shown that the approximate expressions previously derived in the literature by Howard, Mills and Thompson, Kirtman, and Bunker and Longuet‐Higgins can be obtained from these more exact expressions. Finally the infrared and Raman selection rules are summarized and band shapes are discussed.

The molecular symmetry group of dimethylacetylene was defined by Longuet‐Higgins, and its double group was introduced by Hougen. In this paper we determine the form of the normal coordinates of dimethylacetylene and classify them in the double group. Using the exact normal coordinates it is not always possible to obtain selection rules on purely vibrational transitions. However, by approximating the potential function we can obtain ``approximate normal coordinates'' and, thereby, derive ``approximate vibrational selection rules.'' These selection rules prove useful in interpreting the infrared and Raman spectra of dimethylacetylene and other ethanelike molecules that have a low torsional barrier. One important result is that we do not generally expect there to be any coincidences between infrared and Raman fundamental bands.

In this paper it is shown how the effects of the breakdown of the Born-Oppenheimer approximation can be allowed for in the determination of precise values for the bond length and the force constants of a diatomic molecule in a 1 Σ electronic ground state. It is also shown how other parameters, which characterize the extent of the breakdown of the Born-Oppenheimer approximation, can be determined from precise experimental data. The technique is applied to the infrared and microwave data that are available for the hydrogen halides, and for CO, and it is also shown how this theory can be used to interpret the discrepancy that exists between the theoretical ( ab initio ) and experimental vibration-rotation energies of H 2 and D 2 in their electronic ground state. The order of magnitude of the nuclear mass dependence of the bond lengths and force constants obtained by using the Born-Oppenheimer approximation is determined.

The exact rovibronic Hamiltonian of a diatomic molecule is derived, and expressions for the eigenfunctions and eigenvalues are obtained in the adiabatic approximation. This is an improvement over the results obtained using the Born-Oppenheimer approximation. The best possible potential curve of an electronic state of a diatomic molecule is defined and it is shown how this varies with isotopic substitution. The theoretical expression for the electronic isotope shift of a transition is determined from the expressions for the best possible potential curves. This theoretical result is shown to be in good agreement with the observed isotope shifts of the Lyman bands of H 2 , HD, and D 2 . Since the theoretical determination of an electronic isotope shift demands the ab initio calculation of several expectation values, an approximate expression is derived and shown to give good agreement with experiment. The accuracy of the experimental determination of an electronic isotope shift is also discussed.

In this paper we have extended the work of Hougen, Bunker and Johns ( 1 ), in which the vibration-rotation Hamiltonian of a triatomic molecule was derived in a manner that allowed explicitly for the large amplitude of the bending vibration. In this technique the rotation-bending-stretching Hamiltonian is separated, in zeroth-order, into a rotation-bending part and a stretching part. This proves to be much closer to the physics of the motion than the customary separation into a rotation part and a bending-stretching part since interaction terms are much less important and fewer parameters are required. Our extension to the previous work has been to include overall molecular rotation and we have written a computer program to calculate the rotation-bending energy levels E ( v 2 , J ) using this model. The calculation involves, at most, five parameters (the two zero-point bond lengths, the equilibrium bond angle, the quadratic bending force constant, and the potential energy barrier opposing the straightening of the molecule). We have not explicitly included any vibration-rotation interaction constants since the most important of these are an implicit part of the model. We have fitted the rotation-bending energy levels of HCN and DCN in their bent A electronic state and in their ground electronic state, and the rotation-bending energy levels of H 2 O, D 2 O and HDO in their ground electronic state. The agreement between theory and experiment is very satisfactory in all cases, especially when it is considered how few parameters are used. We have also obtained some new experimental results for the A electronic state of HCN and DCN which is used to further test the theory.

The molecular symmetry group of methylsilylacetylene is determined and used to classify the rotational-torsional wavefunctions and normal vibrations of the molecule. The vibrational selection rules are also derived and it is shown how a high resolution analysis of some of the perpendicular fundamental bands in the infra-red spectrum might yield the height of the torsional barrier. The experimental results are shown to be consistent with there being a near zero torsional barrier.

The perpendicular C—H stretching band of dimethylacetylene is studied theoretically. It is shown that the doubling of the main peaks observed by Mills & Thompson (1954) is probably due to vibrational coupling between the two methyl groups. The torsional barrier is estimated to be not greater than about 10 cm -1 , and it is shown how the barrier could be accurately evaluated from a somewhat better-resolved infra-red spectrum.

The present paper reorts a comparative study of enduring behavior changes following human relations training laboratories of three weeks' and two weeks' duration. A behavior change description questionnaire was used eight to ten months after training to elicit descriptions of a subject's postlaboratory behavior changes as seen by the subject himself and seven of his co-workers (including superiors, peers, and subordinates). A matched control sample was obtained and assessed in the same manner. Two interrelated measures of change were derived from the questionnaires: the "total change score," composed of the total number of different changes mentioned by a subject and his co-workers; and the "verified change score," composed of those behavior changes which are mentioned by two or more persons in a set of descriptions. A set of 17 inductively derived content categories were also used to make a qualitative analysis of the changes. While both laboratory trained samples differed from the control sample on both measures, they also differed significantly from each other. Both the perceived change score and the verified change score reveal more changes made by the three-week sample. The content category analysis suggests that the three-week laboratory participants made more overt, pro-active changes, as opposed to the more passive, attitudinal changes made by the two-week sample. Analysis of changes by broad occupational groupings shows differences in response to training which interact with the samples studied. The training designs of the three-week and two-week laboratories are discussed and shown to confound the duration variable. The greater relative emphasis on back-home application of laboratory training in the three-week program is suggested to be a major contributor to the qualitative differences in the kinds of changes made.

In this paper we derive an expression for the vibration-rotation Hamiltonian of a triatomic molecule. In the derivation we use a curvilinear bending coordinate and two rectilinear stretching coordinates in such a way that the Hamiltonian obtained is applicable for any triatomic molecule, linear or bent, and allows for large displacements of the bending coordinate (sometimes said to result from the molecule being “quasi-linear” but, in fact, of general occurrence). We derive a zeroth-order Hamiltonian to describe the energy levels associated with the bending vibration, and are able to fit the experimental results on HCN and DCN better than if we had used the standard formalism of rectilinear (and small) displacements. We also use the formalism to describe the dependence of the rotational constant B on the bending vibrational quantum number and apply the results to the microwave data on CsOH and CsOD.

Implementation, from which flows operational policy, is an integral part of the policymaking process. This phenomenon is examined briefly as a socio-political process, an administrative task, a follow-on from systematic analysis, a problem in the diffusion and utilization of knowledge, and a basic capacity which is differentially distributed among organizations and subject to deliberate change. A three-dimensional framework for assessing the nature of implementation tasks and for making strategic choices in planning implementation is proposed and illustrated. Finally, implementation processes in a federalistic system are described as requiring multi-level participation of four classes of participants: administrative-bureaucratic, political leadership, rational-analytic and constituent elites. A variety of functions must be performed at federal, regional, and local levels to assure policy execution consistent with both policy designs and local contingencies.

Laboratory Training has roots in the blending of research and action. Application interest took precedence in its early development, and the present need is to advance scientific knowledge of training processes and outcomes. Recent studies toward an empirical foundation for training theory are reviewed. Data are presented from a study of perceived behavior changes one year after participation in training. Participants are seen by co-workers as increasing significantly more than controls in cognitive openness, behavioral skill, and understanding of social processes. Long-range changes are correlated with learning measures at time of training. The clear evidence for the impact of laboratory methods for some subjects must be followed by further inquiry which will explicate processes and conditions.

Author Institution: Division of Pure Physics, National Research Council of Canada; Academy of Sciences, Prague

The extent of the magnetic field induced quenching of the fluorescence from the (v′ = 6, J′ = 32) and (v′ = 11, J′ = 128) levels of the B 3Π (Ou+) state of I2 has been measured. A He/Ne laser operating at 6328 A has been used to excite the fluorescence. Combining these measurements with earlier results obtained for the higher vibrational levels allows us to determine the shape of an Ou− repulsive potential energy curve which crosses the B‐state curve. Since the v′ = 6 level is observed to be quenched much more strongly than the levels of higher v′, this Ou− curve crosses the B‐state curve at a low v′ value.

The complex nature of policy problems requires innovative approaches to problem analysis and a new social science interdiscipline focused on policy processes. The Policy Science Program at SUNY Buffalo is designed to advance this field and to train hybrid Ph.D.'s as research-scientists/practitioners. These new policy science professionals will augment policymaking organizations as policy analysts, evaluation researchers, knowledge brokers, research feedback disseminators, process monitors, and consultants. Their training must include research methodology, analytic approaches, orienting conceptual schemes from systems theory, social sciences, and specific problem domains, and operating skills. The curriculum includes both academic and field-training aspects.

The C2H3+ ion has an unusual internal-rotation tunneling degree of freedom in which the three protons rotate around the C2 core with the molecule remaining planar. We have used our semirigid bender Hamiltonian (R. Escribano and P.R. Bunker, J. Mol. Spectry. 122 (1987) 325), with the results of an ab initio calculation of this tunneling potential (R. Lindh et al., Chem. Phys. Letters 139 (1987) 407), to calculate the rotational energy levels and internal-rotation splittings.

A new cholescintigraphic finding, the "hot rim" sign, is reported in a case of acute cholecystitis. Local inflammation in the gallbladder fossa may be the cause of this phenomenon.

The authors report a case of "hot spot" localization on SPECT hepatic scintigraphy secondary to IVC obstruction. The tomographic slices demonstrated the location of the focal increase in radiotracer activity as anterior, within the medial segment of the left lobe of the liver. Radionuclide angiography confirmed the extensive collateral vasculature of IVC obstruction.

Relatively few seven-pinhole collimator systems purchased within the last three years are still in routine use. This paper describes a nontomographic use of the collimator for thyroid scanning. One image is obtained which simultaneously shows seven different projections of the thyroid gland. The diagnosis of thyroid abnormalities can frequently be made from this single composite image without the requirement for additional images. Further information can be obtained when needed by computer processing the image into tomographic slices.