Interior noise prediction methodology: ATDAC theory and validation

The Acoustical Theory for Design of Aircraft Cabins (ATDAC) is a computer program developed to predict interior noise levels inside aircraft and to evaluate the effects of different aircraft configurations on the aircraft acoustical environment. The primary motivation for development of this program is the special interior noise problems associated with advanced turboprop (ATP) aircraft where there is a tonal, low frequency noise problem. Prediction of interior noise levels requires knowledge of the energy sources, the transmission paths, and the relationship between the energy variable and the sound pressure level. The energy sources include engine noise, both airborne and structure-borne; turbulent boundary layer noise; and interior noise sources such as air conditioner noise and auxiliary power unit noise. Since propeller and engine noise prediction programs are widely available, they are not included in ATDAC. Airborne engine noise from any prediction or measurement may be input to this program. This report describes the theory and equations implemented in the ATDAC program

Mismatching Measures of Output and Prices: Implications for Measuring the Comovement of Prices and Output

price output correlation

Evaluation of Student Reactions to Consumer Products

Based on gender role congruence theory, this research sought to understand how consumer perceptions differ for masculinized and feminized products when they are presented by the opposing gender. Additionally, our research sought to understand what role—if any—political affiliation played in the consumer’s perception of the products presented. The results of this study were inconclusive due to a data collection error, however, the study itself serves as a good framework for answering the question of interest and should be rerun to draw meaningful conclusions

Downstaging for hepatocellular cancer: Harm or benefit?

Downstaging of hepatocellular carcinoma (HCC) to enable liver transplantation has become an area of intense interest and research. It may allow a curative option in patients outside widely accepted transplantation criteria, with outcomes that, in some studies, are comparable to transplantation for patients within criteria. There have been conflicting opinions on the best downstaging protocols, criteria for downstaging eligibility and for assessment of response. We therefore aimed to review the literature and evidence for downstaging, as well as considering its drawbacks. Conclusion: Pooled analyses have suggested success in down staging in about half of patients treated, but with higher recurrence rates than patients initially within transplantation criteria. Studies with strict inclusion criteria and mandatory waiting time before transplantation reported survival equivalent to patients who did not require downstaging. In carefully selected patients, there is a role for down staging to provide the chance of transplantation and cure, with acceptable outcomes. Further multi center, well-designed studies are required to clarify who will mostly benefit. Until such data is available, downstaging criteria should be stated within transplantation programs and relevant decisions should be discussed by multidisciplinary teams

Creation of two-dimensional coulomb crystals of ions in oblate Paul traps for quantum simulations

We develop the theory to describe the equilibrium ion positions and phonon modes for a trapped ion quantum simulator in an oblate Paul trap that creates two-dimensional Coulomb crystals in a triangular lattice. By coupling the internal states of the ions to laser beams propagating along the symmetry axis, we study the effective Ising spin-spin interactions that are mediated via the axial phonons and are less sensitive to ion micromotion. We find that the axial mode frequencies permit the programming of Ising interactions with inverse power law spin-spin couplings that can be tuned from uniform to $r^{-3}$ with DC voltages. Such a trap could allow for interesting new geometrical configurations for quantum simulations on moderately sized systems including frustrated magnetism on triangular lattices or Aharonov-Bohm effects on ion tunneling. The trap also incorporates periodic boundary conditions around loops which could be employed to examine time crystals.Comment: 17 pages, 8 figures, submitted to the journal EPJ Quantum Technology for the thematic Series on Quantum Simulation

Passively mode-locked semiconductor laser for coherent population trapping in ⁸⁷Rb

Passively mode-locked semiconductor laser for coherent population trapping in <sup>87</sup>Rb is reported. The laser material used is a 793nm GaAs/Al<sub>x</sub>Ga<sub>1-x</sub>As single quantum well (QW) graded index separate confinement heterostructure