Experimental verification and practical application of torquewhirl theory of rotordynamic instability

A theory developed by Vance in 1978 to explain the destabilizing effect of torque on a whirling rotor was experimentally verified. The measurements made on a specially designed test apparatus are described. New computer models were also developed to investigate the effect of torque on rotordynamic stability of multidisk flexible rotor bearing systems. The effect of torque was found to be most pronounced when the system is already marginally stable from other influences. The modifications required to include torque in a typical shaft transfer matrix are described, and results are shown which identify the type of rotor design most sensitive to load torque

Noise reduction of plenum windows on the façade of a high-rise residential building next to heavy road traffic

Extensive traffic noise transmission loss measurements were carried out inside selected residential units of a standalone 32-storey housing block located next to a very busy and noisy main trunk road in the present study. A total of 35 units, which were all equipped with plenum windows, was surveyed. These plenum windows are intended to help reduce noise exposure of the residents and at the same time allow for a reasonable level of natural ventilation. The results show that the traffic noise transmission losses of the unit façades installed with the plenum windows adopted in this housing block vary between 10.6 and 13.0 dBA and are only weakly dependent on elevation from the trunk road. The results also validate in-situ the prediction model established previously by the authors using laboratory and site mockup data. Generalized models for both empirical and experimental estimation of the traffic noise transmission loss across a residential flat unit façade installed with multiple plenum windows are developed. The differences between their estimations are well within engineering tolerance

Instantonic approach to triple well potential

By using a usual instanton method we obtain the energy splitting due to quantum tunneling through the triple well barrier. It is shown that the term related to the midpoint of the energy splitting in propagator is quite different from that of double well case, in that it is proportional to the algebraic average of the frequencies of the left and central wells.Comment: Revtex, 11 pages, Included one eps figur

Development of an integrated model framework for multi-air-pollutant exposure assessments in high-density cities

Exposure models for some criteria of air pollutants have been intensively developed in past research; multi-air-pollutant exposure models, especially for particulate chemical species, have been however overlooked in Asia. Lack of an integrated model framework to calculate multi-air-pollutant exposure has hindered the combined exposure assessment and the corresponding health assessment. This work applied the land-use regression (LUR) approach to develop an integrated model framework to estimate 2017 annual-average exposure of multiple air pollutants in a typical high-rise and high-density Asian city (Hong Kong, China) including four criteria of gaseous air pollutants (particulate matter with an aerodynamic diameter equal to or less than 10 µm (PM10) and 2.5 µm (PM2.5), nitrogen dioxide (NO2), and ozone (O3)), as well as four major PM10 chemical species. Our integrated multi-air-pollutant exposure model framework is capable of explaining 91 %–97 % of the variability of measured gaseous air pollutant concentration, with the leave-one-out cross-validation R2 values ranging from 0.73 to 0.93. Using the model framework, the spatial distribution of the concentration of various air pollutants at a spatial resolution of 500 m was generated. The LUR model-derived spatial distribution maps revealed weak-to-moderate spatial correlations between the PM10 chemical species and the criteria of air pollutants, which may help to distinguish their independent chronic health effects. In addition, further improvements in the development of air pollution exposure models are discussed. This study proposed an integrated model framework for estimating multi-air-pollutant exposure in high-density and high-rise urban areas, serving an important tool for multi-air-pollutant exposure assessment in epidemiological studies.</p

Rapid communication: Linkage mapping of the porcine immunoreceptor DAP10 and NKG2D genes

Genus and Species. Sus scrofa. Loci. DNAX-activation protein 10 (DAP10) and natural killer cell receptor D (NKG2D). Source and Description of Primers. Primers were designed from the porcine DAP10 and NKG2D sequences (GenBank accession nos. AF285446 and AF285448, respectively). The DAP10 primers were used to amplify approximately 500 bp of the fragment spanning DAP10 exon 4 and DAP12 exon 5. The DAP10 and DAP12 genes are linked in opposite transcriptional orientation, separated by 152 bp (Yim et al., 2001). The NKG2D primers were used to amplify approximately 700 bp of the fragment spanning NKG2D exons 8 and 9

Understanding Financial Market States Using an Artificial Double Auction Market

The ultimate value of theories describing the fundamental mechanisms behind asset prices in financial systems is reflected in the capacity of such theories to understand these systems. Although the models that explain the various states of financial markets offer substantial evidence from the fields of finance, mathematics, and even physics, previous theories that attempt to address the complexities of financial markets in full have been inadequate. We propose an artificial double auction market as an agent-based model to study the origin of complex states in financial markets by characterizing important parameters with an investment strategy that can cover the dynamics of the financial market. The investment strategies of chartist traders in response to new market information should reduce market stability based on the price fluctuations of risky assets. However, fundamentalist traders strategically submit orders based on fundamental value and, thereby stabilize the market. We construct a continuous double auction market and find that the market is controlled by the proportion of chartists, P-c. We show that mimicking the real state of financial markets, which emerges in real financial systems, is given within the range P-c = 0.40 to P-c = 0.85; however, we show that mimicking the efficient market hypothesis state can be generated with values less than P-c = 0.40. In particular, we observe that mimicking a market collapse state is created with values greater than P-c = 0.85, at which point a liquidity shortage occurs, and the phase transition behavior is described at P-c = 0.85.open1132sciescopu

Exclusive Measurement of the Nonmesonic Weak Decay of ^{5}_{\Lambda}He Hypernucleus

We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay (NMWD) of ^{5}_{\Lambda}He formed via the ^{6}Li(\pi^+,K^+) reaction. The energies of two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body decay of \Lambda p --> n p and \Lambda n --> n n, respectively. The ratio of the nucleon pair numbers was N_{nn}/N_{np}=0.45 \pm 0.11(stat)\pm 0.03(syst) in the kinematic region of cos(theta_{NN}) < -0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of \Gamma(\Lambda p --> np)/\Gamma(\Lambda n --> nn). The ratio is consistent with recent theoretical calculations based on the heavy meson/direct quark exchange picture.Comment: Submitted to Phys. Rev. lett., 4 pages, 3 figure