Report on objective ride quality evaluation

The correlation of absorbed power as an objective ride measure to the subjective evaluation for the bus data was investigated. For some individual bus rides the correlations were poor, but when a sufficient number of rides was used to give reasonable sample base, an excellent correlation was obtained. The following logarithmical function was derived: S = 1.7245 1n (39.6849 AP), where S = one subjective rating of the ride; and AP = the absorbed power in watts. A six-degree-of-freedom method developed for aircraft data was completed. Preliminary correlation of absorbed power with ISO standards further enhances the bus ride and absorbed power correlation numbers since the AP's obtained are of the same order of magnitude for both correlations. While it would then appear that one could just use ISO standards, there is no way to add the effect of three degrees of freedom. The absorbed power provides a method of adding the effects due to the three major directions plus the pitch and roll

Nonlinear dynamic response of a uni-directional model for the tile/pad space shuttle thermal protection system

A unidirectional analysis of the nonlinear dynamic behavior of the space shuttle tile/pad thermal protection system is developed and examined for imposed sinusoidal and random motions of the shuttle skin and/or applied tile pressure. The analysis accounts for the highly nonlinear stiffening hysteresis and viscous behavior of the pad which joins the tile to the shuttle skin. Where available, experimental data are used to confirm the validity of the analysis. Both analytical and experimental studies reveal that the system resonant frequency is very high for low amplitude oscillations but decreases rapidly to a minimum value with increasing amplitude. Analytical studies indicate that with still higher amplitude the resonant frequency increases slowly. The nonlinear pad is also responsible for the analytically and experimentally observed distorted response wave shapes having high sharp peaks when the system is subject to sinusoidal loads. Furthermore, energy dissipation in the pad is studied analytically and it is found that the energy dissipated is sufficiently high to cause rapid decay of dynamic transients. Nevertheless, the sharp peaked nonlinear responses of the system lead to higher magnification factors than would be expected in such a highly damped linear system

The Mechanical Impact of the Tibetan Plateau on the Seasonal Evolution of the South Asian Monsoon

The impact of the Tibetan Plateau on the South Asian monsoon is examined using a hierarchy of atmospheric general circulation models. During the premonsoon season and monsoon onset (April–June), when westerly winds over the Southern Tibetan Plateau are still strong, the Tibetan Plateau triggers early monsoon rainfall downstream, particularly over the Bay of Bengal and South China. The downstream moist convection is accompanied by strong monsoonal low-level winds. In experiments where the Tibetan Plateau is removed, monsoon onset occurs about a month later, but the monsoon circulation becomes progressively stronger and reaches comparable strength during the mature phase. During the mature and decaying phase of monsoon (July–September), when westerly winds over the Southern Tibetan Plateau almost disappear, monsoon circulation strength is not much affected by the presence of the Tibetan Plateau. A dry dynamical core with east–west-oriented narrow mountains in the subtropics consistently simulates downstream convergence with background zonal westerlies over the mountain. In a moist atmosphere, the mechanically driven downstream convergence is expected to be associated with significant moisture convergence. The authors speculate that the mechanically driven downstream convergence in the presence of the Tibetan Plateau is responsible for zonally asymmetric monsoon onset, particularly over the Bay of Bengal and South China

Palliative stenting for oesophagogastric cancer: tumour and host factors and prognosis

Objectives: Palliative self-expandable metallic stent (SEMS) insertion is common in patients not suitable for resection of oesophagogastric (OG) cancer. Factors which may determine survival, however, are not clear. The present study examined the relationship between tumour and host factors, including the systemic inflammatory response and survival of patients undergoing palliative SEMS insertion. Methods: Patients with a diagnosis of OG cancer who were considered suitable for palliative SEMS only without systemic therapy were identified. Patient characteristics including Eastern Cooperative Oncology Group performance status, radiological stage and modified Glasgow Prognostic Score (mGPS: 0—C-reactive protein (CRP) ≤10 mg/L; 1—CRP >10 mg/L; 2—CRP >10 mg/L; albumin <35 g/L) were recorded prospectively. The relationship between such characteristics and 3-month survival was examined. Results: 203 patients were included in the final analysis. All patients died during follow-up, with median survival from diagnosis 75 days (IQR 47–157). 78% of patients were systemically inflamed (mGPS >1). On multivariate analysis, only poor performance status (HR 1.23, p=0.025), metastatic disease (HR 2.27, p<0.001) and mGPS (HR 1.25, p=0.021) were associated with shorter survival. The combination of performance status and mGPS stratified 3-month survival of patients without metastatic disease from 88% to 20% (p<0.001) and patients with metastases from 43% to 6% (p=0.059). Similar results were observed when analysis was restricted to patients with oesophageal and junctional cancer (M0: 83%–20%, p=0.008; M1: 33%–8%, p=0.082). Conclusion: Performance status, metastatic disease and mGPS are independent predictors of survival in patients with OG cancer undergoing palliative SEMS insertion. These routinely available markers provide a rational system on which to base decisions regarding prognosis and treatment