Ultrafast Molecular Spectroscopy Using a Hollow-Core Photonic Crystal Fibre Light Source

We demonstrate, for the first time, the application of rare-gas filled hollow-core photonic crystal fibres (HC-PCFs) as tuneable ultraviolet light sources in femtosecond pump-probe spectroscopy. The time-resolved photoelectron imaging technique reveals non-adiabatic dynamical processes operating on three distinct timescales in the styrene molecule following excitation over the 242-258 nm region. These include ultrafast (<100 fs) internal conversion between the S2(pipi*) and S1(pipi*) electronic states and subsequent intramolecular vibrational energy redistribution within S1(pipi*). Compact, cost-effective and highly efficient bench-top HC-PCF sources have huge potential to open up many exciting new avenues for ultrafast spectroscopy in the ultraviolet and vacuum ultraviolet spectral regions. We anticipate that our initial validation of this approach will generate important impetus in this are

Following the excited state relaxation dynamics of indole and 5-hydroxyindole using time-resolved photoelectron spectroscopy

Time-resolved photoelectron spectroscopy was used to obtain new information about the dynamics of electronic relaxation in gas-phase indole and 5-hydroxyindole following UV excitation with femtosecond laser pulses centred at 249 nm and 273 nm. Our analysis of the data was supported by ab initio calculations at the coupled cluster and complete-active-space self-consistent-field levels. The optically bright 1La and 1Lb electronic states of 1\u3c0\u3c0* character and spectroscopically dark and dissociative 1\u3c0\u3c3* states were all found to play a role in the overall relaxation process. In both molecules we conclude that the initially excited 1La state decays non-adiabatically on a sub 100 fs timescale via two competing pathways, populating either the subsequently long-lived 1Lb state or the 1\u3c0\u3c3* state localised along the N-H coordinate, which exhibits a lifetime on the order of 1 ps. In the case of 5-hydroxyindole, we conclude that the 1\u3c0\u3c3* state localised along the O-H coordinate plays little or no role in the relaxation dynamics at the two excitation wavelengths studied.Peer reviewed: YesNRC publication: Ye

Ultraviolet relaxation dynamics in uracil: Time-resolved photoion yield studies using a laser-based thermal desorption source

Wavelength-dependent measurements of the RNA base uracil, undertaken with nanosecond ultraviolet laser pulses, have previously identified a fragment at m/z = 84 (corresponding to the C3H4N2O+ ion) at excitation wavelengths ≤232 nm. This has been interpreted as a possible signature of a theoretically predicted ultrafast ring-opening occurring on a neutral excited state potential energy surface. To further investigate the dynamics of this mechanism, and also the non-adiabatic dynamics operating more generally in uracil, we have used a newly built ultra-high vacuum spectrometer incorporating a laser-based thermal desorption source to perform time-resolved ion-yield measurements at pump wavelengths of 267 nm, 220 nm, and 200 nm. We also report complementary data obtained for the related species 2-thiouracil following 267 nm excitation. Where direct comparisons can be made (267 nm), our findings are in good agreement with the previously reported measurements conducted on these systems using cold molecular beams, demonstrating that the role of initial internal energy on the excited state dynamics is negligible. Our 220 nm and 200 nm data also represent the first reported ultrafast study of uracil at pump wavelengths 3(1ππ*) state. These measurements do not, however, provide any evidence for the appearance of the m/z = 84 fragment within the first few hundred picoseconds following excitation. This key finding indicates that the detection of this specific species in previous nanosecond work is not directly related to an ultrafast ring-opening process. An alternative excited state process, operating on a more extended time scale, remains an open possibility

The role of novel Rydberg-valence behaviour in the non-adiabatic dynamics of tertiary aliphatic amines

Time-resolved photoelectron imaging was used to study non-adiabatic relaxation dynamics in N,N-dimethylisopropylamine, N,N-dimethylpropylamine and N-methylpyrrolidine following excitation at 200 nm.</p

Prospectus, January 10, 1969

VOTE VOTE VOTE!; Spring Concert in March; Tuition Up; 3 New Clubs on Campus; PP Presents First Dynamic Duo; Ask Charlie Brown; Danville Dumps PC, 91-67; IM to Begin Soon; Palma Hits 21 in Loss; Springfield Next Foe; Parkland Falls 89-82https://spark.parkland.edu/prospectus_1969/1014/thumbnail.jp

Prospectus, February 16, 1978

STU-GO VACANCIES FILLED TODAY, TOMORROW; Trail is unopposed for presidential post; Ballje, Berry, Henze vie for veep\u27s job; Staff editorial: Should Parkland foot the bill for vets\u27 education?; Parkland College News in Brief: CHI helps you understand the doctor, SWAMP meets, Land lab has good season, SIU rep here today; Return of the Hilltoppers: Clambering up Mount Parkland -- \u27Because it was there!\u27; Treasury post draws two hopefuls; One running for secretary; Davis seeks PR position; Bundy unopposed in bid for student services post; Three candidates in race for convocations senator; Swanson pursuing office of day senator; Life spanning draws large crowd; Snow day melts extra study time; Will the big bands ever return?; Taped artist interviews at U of I; Toll free tax answers for Illinois residents; \u27Furry friends\u27 contest; Classifieds; State basketball tourney schedule; Women win 10th: Cobras take victory number 20; Long life program lists classes; Cherry Orchard opening is apple of Krannert\u27s eye; Bookworms invited to U of I; It\u27s tourney time; Women beat Kankakee, top .500; Bouncing Bob Basketball Bonanza: If you think LAST week was tough...; Bouncing Bob Basketball Bonanza; Men grab two more winshttps://spark.parkland.edu/prospectus_1978/1025/thumbnail.jp

Photochemical fingerprinting is a sensitive probe for the detection of synthetic cannabinoid receptor agonists; towards robust point-of-care detection

With synthetic cannabinoid receptor agonist (SCRA) use still prevalent across Europe and structurally advanced generations emerging, it is imperative that drug detection methods advance in parallel. SCRAs are a chemically diverse and evolving group, which makes rapid detection challenging. We have previously shown that fluorescence spectral fingerprinting (FSF) has the potential to provide rapid assessment of SCRA presence directly from street material with minimal processing and in saliva. Enhancing the sensitivity and discriminatory ability of this approach has high potential to accelerate the delivery of a point-of-care technology that can be used confidently by a range of stakeholders, from medical to prison staff. We demonstrate that a range of structurally distinct SCRAs are photochemically active and give rise to distinct FSFs after irradiation. To explore this in detail, we have synthesized a model series of compounds which mimic specific structural features of AM-694. Our data show that FSFs are sensitive to chemically conservative changes, with evidence that this relates to shifts in the electronic structure and cross-conjugation. Crucially, we find that the photochemical degradation rate is sensitive to individual structures and gives rise to a specific major product, the mechanism and identification of which we elucidate through density-functional theory (DFT) and time-dependent DFT. We test the potential of our hybrid “photochemical fingerprinting” approach to discriminate SCRAs by demonstrating SCRA detection from a simulated smoking apparatus in saliva. Our study shows the potential of tracking photochemical reactivity via FSFs for enhanced discrimination of SCRAs, with successful integration into a portable device

Twenty questions about design behavior for sustainability, report of the International Expert Panel on behavioral science for design

How behavioral scientists, engineers, and architects can work together to advance how we all understand and practice design—in order to enhance sustainability in the built environment, and beyond.https://www.nature.com/documents/design_behavior_for_sustainability.pdfPublished versio

Working Title Films and Universal : The Integration of a British Production Company into a Hollywood Studio

Working Title Films is arguably the most successful and well-known production company in Britain today. For over 30 years, it has produced a diverse range of critically and commercially successful British films including romantic comedies such as Four Weddings and a Funeral (1994) and Bridget Jones’s Diary (2001), family films like Bean (1997) and Nanny McPhee (2005) and dramas including Atonement (2007) and The Theory of Everything (2014). For the majority of its history, however, Working Title has been defined in business terms by its status as a subsidiary of one of two multinational media conglomerates, PolyGram (1992–8) and Universal (1998–present). The transition between the two began when PolyGram, and its film studio, PolyGram Filmed Entertainment (PFE), was sold to Seagram, the parent company of Universal. This article examines Working Title’s integration into Universal and the evolving media ecology which shaped the processes of development, green-lighting, production, marketing and distribution at play within and between both companies between 1998 and 2006. In these respects, Working Title’s transition between parent companies is a narrative of both continuity and change. Significantly, three key stages of gatekeeping remained common to both the PFE and Universal eras: development, green-lighting and distribution. The institutional perimeters within which these points of decision-making occurred, however, changed considerably. The article concludes by considering the impact of such structures and processes on the films which Working Title produced, particularly their various representations of Britain and ‘Britishness’