A specific case in the classification of woods by FTIR and chemometric: discrimination of Fagales from Malpighiales

Fourier transform infrared (FTIR) spectroscopic data was used to classify wood samples from nine species within the Fagales and Malpighiales using a range of multivariate statistical methods. Taxonomic classification of the family Fagaceae and Betulaceae from Angiosperm Phylogenetic System Classification (APG II System) was successfully performed using supervised pattern recognition techniques. A methodology for wood sample discrimination was developed using both sapwood and heartwood samples. Ten and eight biomarkers emerged from the dataset to discriminate order and family, respectively. In the species studied FTIR in combination with multivariate analysis highlighted significant chemical differences in hemicelluloses, cellulose and guaiacyl (lignin) and shows promise as a suitable approach for wood sample classification

Observation of Wigner cusps in a metallic carbon nanotube

Previous gate-dependent conductance measurements of metallic carbon nanotubes have revealed unexplainable conductance suppressions, occurring at two different gate voltages. These were previously attributed to the gate-dependency of contact resistance. Our gate-dependent conductivity measurements on a metallic nanotube with known chirality show that these bimodal conductance suppressions are the manifestations of Wigner cusps, often seen in atomic and nuclear physics experiments.Comment: 6 pages, 3 figure

Demonstration of Near-Epithermal Neutron Reflective Optics

Specular reflection of neutrons on material surfaces has been demonstrated in the energy range of 0.09-0.7 eV. The results suggest that the applicable energy range of reflective neutron optics can be extended to the near-epithermal region by using existing techniques

Spin dependence in the pp-wave resonance of 139La⃗+n⃗{^{139}\vec{\rm{La}}+\vec{n}}

We measured the spin dependence in a neutron-induced $p$-wave resonance by using a polarized epithermal neutron beam and a polarized nuclear target. Our study focuses on the 0.75~eV $p$-wave resonance state of $^{139}$La+$n$, where largely enhanced parity violation has been observed. We determined the partial neutron width of the $p$-wave resonance by measuring the spin dependence of the neutron absorption cross section between polarized $^{139}\rm{La}$ and polarized neutrons. Our findings serve as a foundation for the quantitative study of the enhancement effect of the discrete symmetry violations caused by mixing between partial amplitudes in the compound nuclei

Spin dependence in the p-wave resonance of La139⃗+n⃗

We measured the spin-dependent cross section at a neutron-induced -wave resonance using a polarized epithermal neutron beam and a polarized nuclear target. Our study focuses on the 0.75 eV -wave resonance of 139La+, where previous experiments have shown a large enhancement of parity violation. The spin dependence of the neutron absorption cross section of polarized 139La and polarized neutrons determines the partial neutron width of the -wave resonance. This partial width is a key parameter needed to determine the sensitivity of this system to possible parity-odd and time reversal-odd interactions beyond the standard model. Our findings therefore serve as a foundation for a future search for time reversal violation in this compound nuclear system.journal articl

High sensitivity of a future search for effects of P-odd/T-odd interactions on the 0.75 eV p-wave resonance in n⃗+139La⃗ forward transmission determined using a pulsed neutron beam

Neutron transmission experiments can offer a new type of highly sensitive search for time-reversal invariance violating (TRIV) effects in nucleon-nucleon interactions via the same enhancement mechanism observed for large parity violating (PV) effects in neutron-induced compound nuclear processes. In these compound processes, the TRIV cross section is given as the product of the PV cross section, a spin factor , and a ratio of TRIV and PV matrix elements. We determined to be 0.59±0.05 for 139La+ using both (,) spectroscopy and (n⃗+139La⃗ ) transmission. This result quantifies for the first time the high sensitivity of the 139La 0.75-eV -wave resonance in a future search for effects of -odd/-odd interactions in (n⃗+139La⃗ ) forward transmission.journal articl