3,358 research outputs found
Buy High Sell Low: Redefining Bean Counting in the Coffee Industry for a Sustainable Future
Charles Manz returns to the JVBL providing ‒ together with several fellow researchers/writers ‒ a case study of a socially responsible business within the coffee industry. Familiar CSR concepts are examined such as Fair Trade and sustainability which foster parity in dealing with buyers while maintaining product quality and reasonable income. The practices of Dean’s Beans, a progressive coffee organization, are examined as a notable demonstration of how a business can fiscally succeed while maintaining a commitment to the triple-bottom-line considerations of people, planet, and profits
Authentic Corporate Social Responsibility Based on Authentic Empowerment: An Exemplary Business Leadership Case
Authors Dillon, Back, and Manz examine the underpinnings of genuine or authentic Corporate Social Responsibility (CSR), noting the direct nexus between stakeholder empowerment and the socially-responsible actions of authentic leaders. Such an empowering leadership approach– involving structural, psychological, developmental, and financial components – is particularly exemplified by a family-owned (Back) wine and cheese company (Fairview Trust), situate in South Africa
Effect of Rotations and Shape Resonances on Photoassociation and Photoacceleration by Ultrashort Infrared Laser Pulses
A quantum dynamical description of an atomic collision pair interacting with the electric field of a short infrared laser pulse is developed. Inelastic processes in the electronic ground state are due to stimulated emission resulting in photoassociation, or absorption leading to photoacceleration. A perturbative approach based on a state space representation is compared with a numerical treatment using a grid representation in coordinate space. Special emphasis is on the role of rotations and, in particular, of shape resonances. It is shown that these quasibound states which are supported by the centrifugal barrier (for J> 0) can be used as initial states to effectively populate a selected bound state with specific vibrational and rotational quantum number (photoassociation), or a partial wave of a scattering state with defined energy and rotational quantum number (photoacceleration). Simulations are carried out for the prototype H + Cl collision pair. Also the effect of averaging over initial conditions (velocity, angular momenta) is investigated for a supersonic beam experiment. For a narrow velocity distribution, we predict the presence of a resonance structure of the association and acceleration probability as a function of the mean collision energy
Quantum Dynamical Aspects of Rotationally and Vibrationally Mediated Photochemistry in Matrices and at Surfaces: HCl/DCl in Ar, and NH3/ND3 at Cu(111)
In this paper, we investigate two extensions of the concept of vibrationally mediated chemistry, from small molecules in the gas phase to small molecules in matrices and at surfaces. Exemplarily, we consider the systems HCl/DCl in Ar, and NH3/ND3 at Cu (111). The transition from isolated systems to the condensed phase calls for new quantum dynamical techniques, and it allows to predict new phenomena. For the case of matrix isolation, we propagate three-dimensional wavepackets representing photodissociated H- or D-atoms which penetrate from the initial cage into the lattice provided by the matrix. The cage exit probabilities are found to depend not only on the initial vibrational, but also on the rotational states, due to the environmental (Oh) symmetry provided by the (fcc) lattice of the matrix. As a consequence, we suggest the extension from vibrationally to rotationally, or rovibrationally mediated chemistry for matrix isolated molecules. For the case of molecules at surfaces, we adopt Gadzuk's jumping wavepacket plus incoherent averaging scheme, applied to an extended two-dimensional Antoniewicz-type model for the surface-molecule bond plus the vibrational coordinate which lends itself to preferential vibrational excitation, (here the umbrella mode of ammonia). The desorption depends selectively on the initial vibrational state. As a consequence, we suggest the extension of traditional desorption induced by electronic transitions DIET to a vibrationally mediated IR+UV DIET scheme which may be used e.g. for enrichment of specific isotopomers at surfaces
From Torsional Spectra to Hamiltonians and Dynamics: Effects of Coupled Bright and Dark States of 9-(N-Carbazolyl) Anthracene
The torsional dynamics of the 9-(N-carbazolyl)-anthracene (C9A) molecule is investigated by means of time-independent (1) and time-dependent (2) quantum-mechanical simulations in a diabatic representation. The study includes effects of surface crossing of the bright S1 state with a dark state.
The intensity pattern of the S0->S1 fluorescence excitation spectrum is used to fit an effective one-dimensional Hamiltonian with a single-minimum potential for the dark state together with diabatic couplings to the double well potential of the bright state.
Based on this Hamiltonian, first predictions for a pump-probe scheme are made. In the pump process the molecules are excited to the S1 state followed by competing torsions in the bright state and diabatic curve crossings to the dark state, depending on the pump frequency. Assuming the probe process to be an ionization from the bright state, the interfering effects of the dark state on the dynamics in the bright state can be monitored in a directly time-dependent way on a fs - ps time scale
Dental Caries Status and Need for Dental Treatment of Pennsylvania Public School Children in Grades 1,3, 9, and 11
Objectives : This cross-sectional study was designed to determine the caries status and provide a general evaluation of the level of dental treatment need of Pennsylvania public school children in grades 1, 3, 9, and 11 on a statewide and regional basis. Methods : Between September 1998 and May 2000, caries status and treatment need were assessed using a school-based dental examination, performed on a representative sample ( n =6,040) of public school children in grades 1, 3, 9, and 11 (age range=6 to 21 years). Children's caries status in the primary and permanent dentition was assessed. Need for treatment was scored on a three-level categorical scale—no treatment need identified, routine treatment need, and urgent treatment need—and was based on the presence and severity of caries and other oral conditions. Population estimates of the prevalence of untreated dental caries, DMFT and dft scores, and treatment need were calculated by grade and geographically, using the six Pennsylvania health districts and the cities of Pittsburgh and Philadelphia. The inequality of caries distribution in the population was assessed for both permanent and primary caries using Lorenz curves and Gini coefficients. Results : Dental caries has remained highly prevalent among Pennsylvania's public school children. Caries levels varied considerably by health districts and city. Urgent treatment needs were significant and also varied by health district and city. Conclusions : Dental caries remains the most prevalent disease affecting Pennsylvania's schoolchildren. Caries status varies significantly by region of the state, suggesting that environmental, social, and demographic contextual factors may be important determinants of disease prevalence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66416/1/j.1752-7325.2004.tb02743.x.pd
Multi-layer atom chips for versatile atom micro manipulation
We employ a combination of optical UV- and electron-beam-lithography to
create an atom chip combining sub-micron wire structures with larger
conventional wires on a single substrate. The new multi-layer fabrication
enables crossed wire configurations, greatly enhancing the flexibility in
designing potentials for ultra cold quantum gases and Bose-Einstein
condensates. Large current densities of >6 x 10^7 A/cm^2 and high voltages of
up to 65 V across 0.3 micron gaps are supported by even the smallest wire
structures. We experimentally demonstrate the flexibility of the next
generation atom chip by producing Bose-Einstein condensates in magnetic traps
created by a combination of wires involving all different fabrication methods
and structure sizes.Comment: 4 pages, 5 figure
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