Optical-frequency dependent modal birefringence and polarization mode dispersion of birefringent single-mode optical fibers over a broadband optical wavelength range

Optical-frequency dependent polarization mode dispersion as well as modal birefringence of three kinds of specially designed hollow-induced birefringent single-mode fiber are measured over an optical frequency range between 345 and 410 THz by optical frequency-domain interferometry.     

Fourier transform emission spectroscopy of the TiF radical in the 407 nm region

Ultraviolet emission spectra of the TiF radical in the 407 nm region have been observed at a resolution of 0.04 cm⁻¹ using a Fourier transform spectrometer. A new electronic assignment of ⁴Γ–X⁴Φ has been proposed. Rotational analysis has been obtained for the 0–0 and 1–1 vibrational bands of the ⁴Γ_5/2–X⁴Φ_3/2, ⁴Γ_9/2–X⁴Φ_7/2, and ⁴Γ_11/2–X⁴Φ_9/2 subbands and the 0–0 band of ⁴Γ_7/2–X⁴Φ_5/2. The lower state rotational and centrifugal distortion constants are consistent with the previous results [J. Mol. Spectrosc. 184 (1997) 186; J. Chem. Phys. 119 (2003) 9496], to the conformation that the lower state of the 407 nm band is the ⁴Φ ground electronic state. Rough estimates of the vibrational interval ΔG(1/2) and the spin–orbit coupling constant A in the ⁴Γ state were also obtained.     

Liquid-phase degradation of HDPE over alkali-treated MFI zeolites with mesopores

The catalytic activities of MFI zeolites treated with NaOH solutions of various concentrations were investigated in the liquid-phase degradation of HDPE. The changes in the crystallinity, pore structure and acidity of MFI zeolites according to the alkali treatment were also examined. The parent MFI zeolite composed of large particles showed very poor activity, but the treatment with moderate NaOH solutions of 0.4-0.7 N enhanced considerably the catalytic activity of MFI zeolite by enlarging its external surface area due to the formation of mesopores. The activity of MFI zeolite was improved by about 20 times treated with 0.5 N NaOH solution. The formation of mesopores also contributed to the enhancement of the yield of liquid products by suppressing further cracking due to the rapid diffusion of products. The treatment with strong NaOH solution, however, lowered the catalytic activity because the treatment caused the loss of both crystalline structure and strong acid sites.     

Diameter dependence of low-energy electron and photon irradiation damage in single-walled carbon nanotubes

Low-energy photon irradiation in an ultra-high vacuum, as well as low-energy electron irradiation, was found to damage single-walled carbon nanotubes, meaning that electronic excitations are solely responsible for the defect formation. The formation and healing of the defects were found to strongly depend on nanotube diameter; that is, thinner nanotubes are more easily damaged and hardly recovered. The results mean that the irradiation damage is prominent in a rolled up graphene sheet, but not in a planar one. The curvature-induced strain energy seems to be essentially important for the damage.     

Joint Function and Arthropathy Severity in Patients with Hemophilia

Background: The Arnold-Hilgartner classification is one of the most popular evaluation systems for the progression hemophilic arthropathy. A previous study reported an association between arthropathy severity and arc range of motion (ROM). However, associations between arthropathy severity and angular ROM and muscle strength remain unclear. AIM: The purpose of this study was to clarify the association between joint function and arthropathy severity in hemophilia. Methods: We studied the knee, ankle, and elbow joints of 31 patients with hemophilia (PWH). The condition of the affected joints was evaluated on the basis of the interview data, joint function measurements, and roentgenography of the affected joints. In assessment of joint function, we evaluated knee strength (flexor, extensor) and grip strength as well as the passive ROM of the elbow, knee, and ankle. During the interview, all patients were asked about the history of intra-articular bleeding over the past year and pain. Results: As arthropathy severity worsened, knee flexor strength, knee extensor strength, grip strength, and ROM (elbow flexion, elbow extension, knee flexion, knee extension, and ankle extension) significantly decreased. Even patients with mild arthropathies experienced knee extensor weakness and extension limitation. In addition, joint function of severe ankle arthropathy was significantly related to the history of intra-articular bleeding and pain. Conclusion: Our results suggest that physical therapy is necessary to improve joint function in PWH and mild or no arthropathy. Pain control and prophylactic hematological management are necessary for patients with severe arthropathy because intra-articular bleeding and pain significantly decrease joint function.