Viewing upcoming talks containing the keyword: 3
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Special Mini-Symposium - Structural Chemistry at Central Facilities
Bragg & Beyond: Combined Diffraction & PDF Studies with High-Energy X-rays
Speaker: Michael Wharmby (DESY Synchrotron, Hamburg)
Bragg & Beyond: Combined Diffraction & PDF Studies with High -Energy X -rays
Synchrotron sources can produce X-rays with significantly higher energies than laboratory s ources. These high -energy X -rays open the possibility to measure total scattering data for a sample, which includes not just the Bragg peaks but also more diffuse scattering features. The Fourier transform of total scattering data yields the Pair Distribut ion Function (PDF) which gives information about local structure (i.e. length scales up to 10s of Angstroms) as well as long range structure. In this talk the possibilities of combined Bragg diffraction and PDF measurements, which are possible at P02.1 (PE TRA III, DESY, Hamburg, Germany), will be discussed in the context of studies of in situ crystallisation and energy materials. Download PDFOn: January 11, 2019 From: 15h40 To: 16h20
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Special Mini-Symposium - Structural Chemistry at Central Facilities
Structural Chemistry at Central Facilities: Understanding Structure-Property Relationships in Energy Materials
Speaker: Julia Payne (St Andrews)
Structural Chemistry at Central Facilities: Understanding Structure -Property Relationships in Energy Materials
It is becoming increasingly important to understand how structures change or evolve during device operation, whether that be in batteries, fuel cells or other devices. However, collecting data under device operating conditions is often difficult, due to f actors such as high operating temperatures and air sensitivity of samples. Here I will discuss our recent progress in the study of energy materials at central facilities, particularly through the use of in-situ and operando techniques. Download PDFOn: January 11, 2019 From: 16h20 To: 17h00
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Cond Mat Seminars
Competing phases and quantum criticality in high Tc cuprate superconductors
Speaker: Antony Carrington (University of Bristol)
Several theories have attempted to explain high temperature superconductivity in cuprates in terms of a quantum critical point close to optimal doping. Analogy to other systems, such as heavy fermions or iron-based materials, would support this picture however in the cuprates the nature and/or existence of a quantum critical point is not clear. It is not clear what is the ordered phase is. Candidates include the enigmatic pseudogap phase or the charge density wave (CDW) phase. Here, I will talk about high field measurements of transport properties which may shed some light on this problem. First I will describe high field measurements of the Hall effect in underdoped YBa2Cu3O6+x (Y123) at pressures up to 8GPa. Tc is increased by pressure in a similar way to chemical doping, but its effect on the CDW seems to be very different. Second, I will show measurements of the Hall coefficient of the overdoped cuprate Tl2Ba2CuO6+x (Tl-2201), which reveal how the effective number of charge carriers varies in the overdoped regime. Surprisingly, the Hall number n_H is not found to vary like 1+p (p=doped holes) until it is far overdoped. This casts doubt on the recent suggestion that the closing of the pseudogap causes a reconstruction of the Fermi surface
On: January 25, 2019 From: 15h00 To: 16h00
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EaStCHEM ColloquiaMore than just location- expanding the use of PAINT for multi-dimensional imaging
Speaker: Mathew Horrocks (Edinburgh)
More than just location - expanding the use of PAINT for multi -dimensional imagin g Super -resolution techniques allow biological systems to be studied at the nanoscale, but are usually restricted to providing positional information only. Point Accumulation for Imaging in Nanoscale Topography (PAINT) [1] makes use of diffusing probes th at are localised as they bind to a surface. We have further developed this technique to provide further information on the environment of the fluorophore [2]. This was achieved by adapting a total internal reflection fluorescence microscope by inserting a diffraction grating in the image plane, allowing both the position and wavelength of single emitters to be determined simultaneously. We have used this with a probe whose wavelength varies depending on its environment to nanoscopically map the hydrophobici ty of liposomes, amyloid aggregates and cells. Although demonstrated with a hydrophobicity probe, this technique is applicable to many other wavelength shifting dyes.
Additionally, we have recently demonstrated the versatility of DNA PAINT [3] through th e use of an aptamer specific to amyloid structure [4] to image endogenous protein aggregates formed in Parkinson’s disease patient derived neurons [5]. The use of DNA PAINT with aptamers is simple to implement, only requiring an extension of the sequence b y eight bases to enable super -resolution imaging.
References: 1. Sharonov, A. & Hochstrasser, R. M. Wide -field subdiffraction imaging by accumulated binding of diffusing probes. Proc. Natl. Acad. Sci. 103, 18911 –18916 (2006). 2. Bongiovanni, M. N. et al. Multi -dimensional super -resolution imaging enables surface hydrophobicity mapping. Nat. Commun. 7, ncomms13544 (2016). 3. Jungmann, R. et al. Multiplexed 3D cellular super -resolution imaging with DNA -PAINT and Exchange - PAINT. N at. Methods 11, 313 –318 (2014). 4. Tsukakoshi, K., Abe, K., Sode, K. & Ikebukuro, K. Selection of DNA Aptamers That Recognize α - Synuclein Oligomers Using a Competitive Screening Method. Anal. Chem. 84, 5542 –5547 (2012). 5. Devine, M. J. et al. Parkinson’s disease induced pluripotent stem cells with triplication of the α - synuclein locus. Nat. Commun. 2, ncomms1453 (2011). Download PDFOn: January 30, 2019 From: 14h00 To: 15h00
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EaStCHEM ColloquiaUsing ab initio approaches to model, predict and understand the optical properties of organic and inorganic dyes - Joint Chemistry/Physics Colloquium
Speaker: Denis Jacquemin (Nantes)
Using ab initio approaches to model, predict and understand the optical properties of organic and inorganic dyes Denis Jacquemin Laboratoire CEISAM, UMR CNRS n°6230, Université de Nantes, 2, rue de la Houssinière, 44322 Nantes, Cedex 3, France. Denis.Jacquemin@univ -nantes.fr During this lecture, I will illustrate some of the successes and failures of Time - Dependent Density Functional Theory (TD -DFT) in simulating the properties of electronically excited -states, with a specific interest on structu res of interest for dye chemistry. 1-2 Notably, I will discuss the importance of calculating vibronic effects to obtain accurate comparisons with experimental data, including 0 -0 energies and band shapes, and illustrate this aspect with several examples. 3 I will also present examples of applications of TD -DFT to real -life structures used in LEDs focussing on two examples: ESIPT -based organic dyes for white OLEDs 4 and inorganic complexes used in blue/green/red phosphors. 5
1 D. Jacquemin, C. Adamo , Chem. Soc. Rev. , 2013 , 42 , 845 . 2 D. Jacquemin, C. Adamo , Top. Curr. Chem.. , 2016 , 368 , 345 . 3 F. Santoro, D. Jacquemin, Wires. Comput. Mol. Sci. 2016 , 6, 460. 4 A. Steffen, K. Costuas, A. Bouccekkine, M. H. Thibault, A. Beeby, A. S. Batsanov, D. Jacquemin, A. Charaf -Eddin, J. F. Halet, T. D. Marder Inorg. Chem. , 2014 , 53 , 7055 . 5 E. Heyer, K. Benelhadj, S. Budzak, D. Jacquemin, J. Massue, G. Ulrich Chem. Eur. J ., 2017 , 23 , 7324 . 6 D W . Zhang, D. Jacquemin , Q. Peng, Z. Suhai, D. Escudero, J. Phys. Chem . C, 2018 , 122 , 6340 . Download PDFOn: February 6, 2019 From: 14h00 To: 15h00
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Physics and Astronomy Colloquia
Using ab initio approaches to model, predict and understand the optical properties of organic and inorganic dyes
Speaker: Prof. Denis Jacquemin (Université de Nantes)
During this lecture, I will illustrate some of the successes and failures of Time-Dependent Density Functional Theory (TD-DFT) in simulating the properties of electronically excited-states, with a specific interest on structures of interest for dye chemistry.1-2 Notably, I will discuss the importance of calculating vibronic effects to obtain accurate comparisons with experimental data, including 0-0 energies and band shapes, and illustrate this aspect with several examples.3 I will also present examples of applications of TD-DFT to real-life structures used in LEDs focussing on two examples: ESIPT-based organic dyes for white OLEDs4 and inorganic complexes used in blue/green/red phosphors.5
On: February 6, 2019 From: 14h00 To: 15h00
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