Search

Your search keyword '"Telkki, Ville-Veikko"' showing total 390 results
Start Over Author "Telkki, Ville-Veikko"
390 results on '"Telkki, Ville-Veikko"'

16. Comprehensive characterization of waterlogged archaeological wood by NMR relaxometry, diffusometry, micro-imaging and cryoporometry.

Author

Stagno, Valeria, Mankinen, Otto, Mailhiot, Sarah, Telkki, Ville-Veikko, and Capuani, Silvia

Abstract

Chemical, physical, and biological decay may partially or totally hide the historical and technological information carried by waterlogged wood. Investigation of the above-mentioned decay processes is essential to assess the wood preservation state, and it is important to find new methods for the consolidation and safeguarding of wooden archaeological heritage. A conventional method for assessing the wood preservation state is light microscopy. However, the method requires sample slicing, which is destructive and challenging when dealing with fragile and spongy submerged remains of heritage wood. To this end, a promising alternative non-destructive technique is proton nuclear magnetic resonance (1H-NMR) which considers wood as a porous system. This work aimed to perform a comprehensive analysis of structures, porosity, water distribution, decay, and possible structural inclusions of three archaeological waterlogged wood fragments of the Roman age using NMR relaxometry, micro-imaging (μ-MRI), NMR diffusometry, and NMR cryoporometry. The results were compared with a similar analysis of the three contemporary wood samples of the same species. The multimodal approach presented in this study allowed us to cover all the dimensional scales of wood, from nanometers to sub-millimeters, and reconstruct the alteration of the entire archaeological wood fragment caused by degradation. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

18. Gas Uptake and Thermodynamics in Porous Liquids Elucidated by 129Xe NMR

Author

Mailhiot, Sarah E., primary, Peuravaara, Petri, additional, Egleston, Benjamin D., additional, Kearsey, Rachel J., additional, Mareš, Jiří, additional, Komulainen, Sanna, additional, Selent, Anne, additional, Kantola, Anu M., additional, Cooper, Andrew I., additional, Vaara, Juha, additional, Greenaway, Rebecca L., additional, Lantto, Perttu, additional, and Telkki, Ville-Veikko, additional

Published
2024
Full Text
View/download PDF

24. Ultrafast T1–T1ρNMR for Correlating Different Motional Regimes of Molecules

Author

Tolkkinen, Katja, Mankinen, Otto, Mailhiot, Sarah E., and Telkki, Ville-Veikko

Abstract

Nuclear magnetic resonance (NMR) relaxation times provide detailed information about molecular motions and local chemical environments. Longitudinal T1relaxation time is most often sensitive to relatively fast, nano- to picosecond ranges of molecular motion. Rotating frame T1ρrelaxation time reflects a much slower, micro- to millisecond range of motion, and the motional regime can be tuned by changing spin-lock field strength. Conventional methods for measuring T1and T1ρrelaxation times are time-consuming, since experiments must be repeated many times with incremented magnetization recovery or decay delay. In this work, we introduce two novel and efficient NMR methods to correlate the T1and T1ρrelaxation times. The first method, IR-SPICY, combines the conventional T1inversion recovery (IR) with the single-scan T1ρdetection-based spin-lock cycle (SPICY). The second method, ultrafast (UF) IR-SPICY, allows measurement of whole two-dimensional T1–T1ρcorrelation data in a single scan, in a couple of seconds, based on spatial encoding of the T1dimension. We demonstrate the performance of the methods by studying relaxation of water in porous silica and hydrogel samples, latter acting as a model of the articular cartilage extracellular matrix. The methods allow correlating different molecular motional regimes, potentially providing unprecedented information about various chemical and biochemical systems, such as structures and fluid dynamics in porous materials, macromolecular changes in tissues, and protein dynamics. One to three orders of magnitude shortened experiment time enable the studies of changing or degrading samples. Furthermore, the single-scan approach may significantly facilitate the use of modern nuclear-spin hyperpolarization techniques to enhance the sensitivity of T1–T1ρmeasurements by several orders of magnitude.

Published
2024
Full Text
View/download PDF

25. Melting of aqueous NaCl solutions in porous materials: shifted phase transition distribution (SIDI) approach for determining NMR cryoporometry pore size distributions

Author

Mailhiot, Sarah E., Tolkkinen, Katja, Henschel, Henning, Mareš, Jiří, Hanni, Matti, Nieminen, Miika T., Telkki, Ville-Veikko, Mailhiot, Sarah E., Tolkkinen, Katja, Henschel, Henning, Mareš, Jiří, Hanni, Matti, Nieminen, Miika T., and Telkki, Ville-Veikko

Abstract

Nuclear magnetic resonance cryoporometry (NMRC) and differential scanning calorimetry thermoporometry (DSC-TPM) are powerful methods for measuring mesopore size distributions. The methods are based on the fact that, according to the Gibbs–Thomson equation, the melting point depression of a liquid confined to a pore is inversely proportional to the pore size. However, aqueous salt solutions, which inherently exist in a broad range of biological porous materials as well as technological applications such as electrolytes, do not melt at a single temperature. This causes artefacts in the pore size distributions extracted by traditional Gibbs–Thomson analysis of NMRC and DSC-TPM data. Bulk aqueous NaCl solutions are known to have a broad distribution of melting points between the eutectic and pure water phase transition points (252–273 K). Here, we hypothesize that, when aqueous NaCl solution (saline) is confined to a small pore, the whole melting point distribution is shifted toward lower temperatures by the value predicted by the Gibbs–Thomson equation. We show that this so-called shifted phase transition distribution (SIDI) approach removes the artefacts arising from the traditional Gibbs–Thomson analysis and gives correct pore size distributions for saline saturated mesoporous silica gel and controlled pore materials analyzed by NMR cryoporometry. Furthermore, we demonstrate that the method can be used for determining pore sizes in collagen–chondroitin sulphate hydrogels resembling the composition of the extracellular matrix of articular cartilage. It is straightforward to apply the SIDI analysis for DSC-TMP data as well.

Published
2024
Full Text
View/download PDF

36. CAT on MOUSE: Control and automation of temperature for single‐sided NMR instruments such as NMR‐MOUSE.

Author

Mailhiot, Sarah, Mankinen, Otto, Li, Jing, Kharbanda, Yashu, Telkki, Ville‐Veikko, and Urbańczyk, Mateusz

Subjects
TEMPERATURE control, ACETIC acid, MICE, RESEARCH personnel, TIME measurements
Abstract

Temperature‐dependent experiments are a rapidly growing area of interest for low‐field NMR. In this work, we present a new device for wide‐range temperature control for single‐sided NMR instruments. The presented device, called CAT, is simple to build, inexpensive, and easy to modify to accommodate different samples. We present the capabilities of the device using a freezing temperature study of acetic acid/water mixtures. Additionally, we present the stability of the device over long measurement times. We believe that by introducing such a device with an open‐source design, we allow researchers to use it in a wide range of applications and to fully incorporate variable‐temperature studies in the world of single‐sided instruments. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

41. Quantifying the Diffusion of a Fluid through Membranes by Remote Detection MRI

Author

Telkki, Ville-Veikko, Hilty, Christian, Garcia, Sandra, Harel, Elad, and Pines, Alexander

Subjects
Materials science, remote detection xenon nuclear magnetic resonance magnetic resonance NMR imaging MRI diffusion membrane
Abstract

We present a method to measure self-diffusion across membranes without the need for concentration or pressure gradients. Hyperpolarized xenon in combination with remote detection of NMR allows the measurement of membrane permeation, even in the gas phase. The resulting images allow quantification of the amount of fluid diffused through the membrane, and represent an alternative, potentially more precise way of measuring a membrane diffusion coefficient. The use of remote detection of NMR allows for non-invasive signal encoding coupled to sensitive detection, making this approach ideal for the study of diffusion in intact devices such as fuel cells or separation systems.

Published
2008

46. SPICY: a method for single scan rotating frame relaxometry

Author

Tolkkinen, Katja, primary, Mailhiot, Sarah E., additional, Selent, Anne, additional, Mankinen, Otto, additional, Henschel, Henning, additional, Nieminen, Miika T., additional, Hanni, Matti, additional, Kantola, Anu M., additional, Liimatainen, Timo, additional, and Telkki, Ville-Veikko, additional

Published
2023
Full Text
View/download PDF

47. Conversion of Highly Polymerized Lignin into Monophenolic Products Via Pyrolysis: A Comparative Study Of Acidic and Alkaline Depolymerization Pretreatments Using Deep Eutectic Solvents

Author

Yue, Xin, primary, Lin, Jinxin, additional, Suopajärvi, Terhi, additional, Mankinen, Otto, additional, Mikkelson, Atte, additional, Liu, Rui, additional, Huttunen, Harri, additional, Xu, Prof. Chunlin, additional, Telkki, Ville‐Veikko, additional, Sun, Shiron, additional, and Liimatainen, Henrikki, additional

Published
2023
Full Text
View/download PDF

49. High-Resolution Reconstruction for Multidimensional Laplace NMR

Author

Lin, Enping, Telkki, Ville-Veikko, Lin, Xiaoqing, Huang, Chengda, Zhan, Haolin, Yang, Yu, Huang, Yuqing, and Chen, Zhong

Subjects
Letter, Condensed Matter::Strongly Correlated Electrons
Abstract

As a perfect complement to conventional NMR that aims for chemical structure elucidation, Laplace NMR constitutes a powerful technique to study spin relaxation and diffusion, revealing information on molecular motions and spin interactions. Different from conventional NMR adopting Fourier transform to deal with the acquired data, Laplace NMR relies on specially designed signal processing and reconstruction algorithms resembling the inverse Laplace transform, and it generally faces severe challenges in cases where high spectral resolution and high spectral dimensionality are required. Herein, based on the tensor technique for high-dimensional problems and the sparsity assumption, we propose a general method for high-resolution reconstruction of multidimensional Laplace NMR data. We show that the proposed method can reconstruct multidimensional Laplace NMR spectra in a high-resolution manner for exponentially decaying relaxation and diffusion data acquired by commercial NMR instruments. Therefore, it would broaden the scope of multidimensional Laplace NMR applications.

Published
2021

Catalog

Books, media, physical & digital resources
See catalog results