One-dimensional alignment of molecules in the adiabatic limit, where the pulse duration greatly exceeds the molecular rotational periods, is studied experimentally. Four different asymmetric top molecules (iodobenzene, p-diiodobenzene, 3,4-dibromothiophene, and 4,4'-dibromobiphenyl), rotationally cooled through a high pressure supersonic pulsed valve, are aligned by a 9-ns-long pulse. Their orientations are measured through Coulomb explosion, induced by a 130-fs-long pulse, and by recording the direction of the recoiling ions. The paper focuses on the crucial role of the initial rotational temperature for the degree of alignment. In particular, we show that at molecular temperatures in the 1 K range very strong alignment is obtained already at intensities of a few times 10(11) W/cm2 for all four molecules. At the highest intensities (approximately 10(12) W/cm2) the molecules can tolerate without ionizing
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.2388273 | DOI Listing |
Braz J Biol
January 2025
Universidade Tecnológica Federal do Paraná - UTFPR, Departmeno de Química e Ciências Biológicas, Francisco Beltrão, PR, Brasil.
Studies show that propolis has antimicrobial, antifungal, antiviral, anti-inflammatory, antioxidant, antitumor, and immunomodulatory properties, and may protect against diseases such as diabetes, cardiovascular disease, and cancer. We aimed to extract compounds of brown propolis with hydroalcoholic solvents and evaluate their cytotoxic activity on tumor and non-tumor cells by MTT test. We tested the solute:solvent ratio (ethanol:water) and extraction time in a Shaker incubator (710 rpm) before conducting a central composite rotational design (CCRD) to optimize time and solvent mixture.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, Saitama University, Saitama City, Saitama 338-8570, Japan.
Rate coefficients for ion-polar-molecule reactions between acetonitrile molecules (CHCN) and nitrogen molecular ions (N), which are of importance to the upper atmospheric chemistry of Saturn's moon Titan, were measured for the first time at low translational temperatures. In the experiments, the reaction between sympathetically cooled N ions embedded in laser-cooled Ca Coulomb crystals and velocity-selected acetonitrile molecules generated using a wavy Stark velocity filter was studied to determine the reaction rate coefficients. Capture rate coefficients calculated by the Su-Chesnavich approach and by the perturbed rotational state theory considering the rotational state distribution of CHCN were compared to the experimental rate coefficients.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Department of Mechanical Engineering and Technology Management, Norwegian University of Life Sciences, N-1433 AS, Norway.
Hybrid molecular ferroelectrics with orientationally disordered mesophases offer significant promise as lead-free alternatives to traditional inorganic ferroelectrics owing to properties such as room temperature ferroelectricity, low-energy synthesis, malleability, and potential for multiaxial polarization. The ferroelectric molecular salt HdabcoClO is of particular interest due to its ultrafast ferroelectric room-temperature switching. However, so far, there is limited understanding of the nature of dynamical disorder arising in these compounds.
View Article and Find Full Text PDFHeliyon
January 2025
Environmental Intelligence for Global Change Lab, Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Ponzio 34/5, 20133, Milan, Italy.
Understanding climate change in a precise and timely manner may assist in gauging the occurrence and seriousness of its impacts, thereby boosting the adaptive capacity and responsiveness of farmers. This investigation looks into farmers' knowledge of climate change, their perception of risks and impacts, and the strategies they anticipate to tackle the challenges of adaptation. A well-structured online survey covering risk awareness, perception, and adaptation was used to randomly sample 460 respondents from 12 irrigation districts in northern Italy.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Engineering Mechanics, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
We here explore confinement-induced assembly of whey protein nanofibrils (PNFs) into microscale fibers using microfocused synchrotron X-ray scattering. Solvent evaporation aligns the PNFs into anisotropic fibers, and the process is followed in situ by scattering experiments within a droplet of PNF dispersion. We find an optimal temperature at which the order parameter of the protein fiber is maximized, suggesting that the degree of order results from a balance between the time scales of the forced alignment and the rotational diffusion of the fibrils.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!