A Framework of Transformational Leadership Concepts Proposed for Undergraduate College and University Student Development and Student Affairs Leadership Programs

Educating undergraduate students in the area of leadership has long been part of the educational mission of many public and private institutions of higher education in the United States. At many of these colleges and universities, leadership education and training has been accomplished by programs directed by student development or student affairs divisions of the institution. The purpose of this study was to identify a framework of transformational leadership concepts that could be integrated into existing student development/affairs leadership programs. The study\u27s objectives were: (1) to obtain expert opinion regarding transformational leadership concepts to be used; (2) to verify whether or not the concepts are found in the current literature and presently included in a select number of leadership programs; and (3) to provide a framework for integrating the concepts into existing programs. The methodology used combined the qualitative research techniques of the Delphi Technique and the Focus Group Interview. A panel of seven professionals, identified as experts in the area of transformational leadership, completed two rounds of questionnaires. The questionnaires collected nominations from panelists on: (1) what concepts would be necessary to introduce the topic of transformational leadership to undergraduates in a leadership program; (2) what sequence these concepts should be presented in; and (3) how these transformational leadership concepts could be best communicated to undergraduate students. Some of the findings of the study were: (1) Empowerment, Shared Power/Shared Leadership, Vision and Values/Ethics were nominated as the transformational leadership concepts to be included in the framework. (2) These concepts were found in the literature, but as a rule were not included in a select number of current programs. (3) One example of a typical suggestion made by several panelists was that leadership training should be integrated with each student\u27s personal experience. Finally, based on his expert opinion, the researcher suggested additional transformational leadership concepts and strategies for integrating concepts into student development/affairs leadership programs

Quantum cascade laser frequency stabilisation at the sub-Hz level

Quantum Cascade Lasers (QCL) are increasingly being used to probe the mid-infrared "molecular fingerprint" region. This prompted efforts towards improving their spectral performance, in order to reach ever-higher resolution and precision. Here, we report the stabilisation of a QCL onto an optical frequency comb. We demonstrate a relative stability and accuracy of 2x10-15 and 10-14, respectively. The comb is stabilised to a remote near-infrared ultra-stable laser referenced to frequency primary standards, whose signal is transferred via an optical fibre link. The stability and frequency traceability of our QCL exceed those demonstrated so far by two orders of magnitude. As a demonstration of its capability, we then use it to perform high-resolution molecular spectroscopy. We measure absorption frequencies with an 8x10-13 relative uncertainty. This confirms the potential of this setup for ultra-high precision measurements with molecules, such as our ongoing effort towards testing the parity symmetry by probing chiral species

Optical-feedback cavity-enhanced absorption spectroscopy with a quantum-cascade laser yields the lowest formaldehyde detection limit

International audienceWe report on the first application of Optical Feedback-Cavity Enhanced Absorption Spectroscopy to formaldehyde trace gas analysis at mid-infrared wavelengths. A continuous-wave room-temperature, distributed-feedback quantum cascade laser emitting around 1,769 cm-1 has been successfully coupled to an optical cavity with finesse 10,000 in an OF-CEAS spectrometer operating on the ν2 fundamental absorption band of formaldehyde. This compact setup (easily transportable) is able to monitor H2CO at ambient concentrations within few seconds, presently limited by the sample exchange rate. The minimum detectable absorption is 1.6 × 10-9 cm-1 for a single laser scan (100 ms, 100 data points), with a detectable H2CO mixing ratio of 60 pptv at 10 Hz. The corresponding detection limit at 1 Hz is 5 × 10-10 cm-1, with a normalized figure of merit of 5 × 10-11cm^{-1}/sqrtHz (100 data points recorded in each spectrum taken at 10 Hz rate). A preliminary Allan variance analysis shows white noise averaging down to a minimum detection limit of 5 pptv at an optimal integration time of 10 s, which is significantly better than previous results based on multi-pass or cavity-enhanced tunable QCL absorption spectroscopy

Doppler-Broadening Gas Thermometry at 1.39 μm: Towards a New Spectroscopic Determination of the Boltzmann Constant

The expression of the Doppler width of a spectral line, valid for a gaseous sample at thermodynamic equilibrium, represents a powerful tool to link the thermodynamic temperature to an optical frequency. This is the basis of a relatively new method of primary gas thermometry, known as Doppler broadening thermometry. Implemented at the Second University of Naples on H218O molecules at the temperature of the triple point of water, this method has recently allowed to determine the Boltzmann constant with a global uncertainty of 24 parts over 106. Even though this is the best result ever obtained by using an optical method, its uncertainty is still far from the requirement for the new definition of the unit kelvin. To this end, Doppler broadening thermometry should approach the accuracy of 1 part per million. In this paper, we will report on our recent efforts to further develop and optimize Doppler broadening thermometry at 1.39 μm, using acetylene as a molecular target. Main progresses and current limitations will be highlighted

Optical-Feedback Cavity-Enhanced Absorption Spectroscopy with a quantum-cascade laser yields the lowest formaldehyde detection limit

We report on the first application of Optical Feedback-Cavity Enhanced Absorption Spectroscopy to formaldehyde trace gas analysis at mid-infrared wavelengths. A continuous-wave room-temperature, distributed-feedback quantum cascade laser emitting around 1,769 cm-1 has been successfully coupled to an optical cavity with finesse 10,000 in an OF-CEAS spectrometer operating on the v2 fundamental absorption band of formaldehyde. This compact setup (easily transportable) is able to monitor H2CO at ambient concentrations within few seconds, presently limited by the sample exchange rate. The minimum detectable absorption is 1.6×10-9 cm-1 for a single laser scan (100 ms, 100 data points), with a detectable H2CO mixing ratio of 60 pptv at 10 Hz. The corresponding detection limit at 1 Hz is 5 × 10-10 cm-1, with a normalized figure of merit of 5 × 10-11cm-1= √Hz (100 data points recorded in each spectrum taken at 10 Hz rate). A preliminary Allan variance analysis shows white noise averaging down to a minimum detection limit of 5 pptv at an optimal integration time of 10 s, which is significantly better than previous results based on multi-pass or cavity-enhanced tunable QCL absorption spectroscopy. © 2013 Springer-Verlag Berlin Heidelberg

Trace measurement of BrO at the ppt level by a transportable mode-locked frequency-doubled cavity-enhanced spectrometer

International audiencePptv levels of BrO radical have been detected around 338.5-nm wavelength probing a rotationally structured A←X (7,0) electronic transition using mode-locked cavity-enhanced spectroscopy (ML-CEAS). The spectrometer is composed by a widely tunable, broadband frequency-doubled Ti:Sa mode-locked frequency comb laser injected into a high-finesse optical cavity and a high-resolution spectrometer based on a high-order diffraction grating and a high-sensitivity back-thinned CCD camera. A typical minimum detectable absorption coefficient of 1×10-9 cm-1 in 30 s of acquisition has been achieved, leading to a detection limit of 1.7 parts per trillion of BrO at atmospheric pressure. The compact and robust ultrasensitive broadband UV spectrometer is intended to be employed for in situ long-term direct measurements of BrO and other halogenated radicals, thus responding to the lack of analytical techniques to monitor the concentrations of such highly chemically reactive species

Speed-dependent effects in the near-infrared spectrum of self-colliding H218O molecules

The absorption line shape of a given H2O18 vibration-rotation line at 1.38 μm was deeply investigated using a spectroscopic approach based upon the use of a pair of offset-frequency locked extended-cavity diode lasers. This dual-laser apparatus ensures extreme levels of accuracy in controlling and measuring any variation of the laser frequency around a given absolute reference. As a result, high levels of precision and accuracy were reached in the observation of a molecular absorption line shape in the near infrared. A variety of semiclassical models, accounting for Dicke narrowing and speed-dependent effects, were implemented and tested in order to describe the physical situation of self-colliding H2O18 molecules. Our study demonstrates that the molecular confinement alone is unable to explain entirely the departures from the Voigt profile and that the speed dependence of pressure-induced broadening and shift cannot be ignored, even in the case of pure water samples at relatively small pressures. The absorption spectrum was successfully interpolated using the uncorrelated version of the speed-dependent Galatry profile, with a hypergeometric dependence on the absorber speed for both pressure broadening and pressure shift parameters, thus reaching an agreement between theory and experiment at the level of 5×10−5

Dual-laser absorption spectroscopy ofC2H2at1.4μm

Spectroscopic parameters (line intensity factor, pressure self-broadening, and shifting coefficients) of C2H2 at 1.4 μm were accurately measured using a dual-laser approach, based upon the technique of optical phase locking. This generated an absolute frequency scale underneath the absorption spectra. A pair of extended-cavity diode laserswas used. One of them, the probe laser, is forced to maintain a precise frequency offset from a reference laser, which is an optical frequency standard based on noise-immune cavity-enhanced optical heterodyne molecular spectroscopy. Laser-gas interaction takes place inside an isothermal multipass cell that is stabilized at the temperature of the triple point of water. The fidelity in the observation of the shape associated to the Pe(14) line of the 2ν3 + ν5 band allowed us to measure the spectroscopic parameters, with a global uncertainty for the line strength of 0.22%

Optical-Feedback Cavity-Enhanced Absorption spectroscopy detects ppt traces of Formaldehyde for the validation of air plasma treatment system

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