Comparative study of turbulence models in predicting hypersonic inlet flows

A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared very well with the experimental data, and performed better than the Thomas model near the walls

Achieving hip fracture surgery within 36 hours: an investigation of risk factors to surgical delay and recommendations for practice

BACKGROUND: The UK hip fracture best practice tariff (BPT) aims to deliver hip fracture surgery within 36 h of admission. Ensuring that delays are reserved for conditions which compromise survival, but are responsive to medical optimisation, would help to achieve this target. We aimed to identify medical risk factors of surgical delay, and assess their impact on mortality. MATERIALS AND METHODS: Prospectively collected patient data was obtained from the National Hip Fracture Database (NHFD). Medical determinants of surgical delay were identified and analysed using a multivariate regression analysis. The mortality risk associated with each factor contributing to surgical delay was then calculated. RESULTS: A total 1361 patients underwent hip fracture surgery, of which 537 patients (39.5 %) received surgery within 36 h of admission. Following multivariate analyses, only hyponatraemia was deduced to be a significant risk factor for delay RR = 1.24 (95 % CI 1.06-1.44). However, following a validated propensity score matching process, a Pearson chi-square test failed to demonstrate a statistical difference in mortality incidence between the hypo- and normonatraemic patients [χ (2) (1, N = 512) = 0.10, p = 0.757]. CONCLUSIONS: Hip fracture surgery should not be delayed in the presence of non-severe and isolated hyponatraemia. Instead, surgical delay may only be warranted in the presence of medical conditions which contribute to mortality and are optimisable. LEVEL OF EVIDENCE: III

C-band superconductor/semiconductor hybrid field-effect transistor amplifier on a LaAlO3 substrate

A single-stage C-band superconductor/semiconductor hybrid field-effect transistor amplifier was designed, fabricated, and tested at 77 K. The large area (1 inch x 0.5 inches) high temperature superconducting Tl-Ba-Ca-Cu-O (TBCCO) thin film was rf magnetron sputtered onto a LaAlO3 substrate. The film had a transition temperature of about 92 K after it was patterned and etched. The amplifier showed a gain of 6 dB and a 3 dB bandwidth of 100 MHz centered at 7.9 GHz. An identical gold amplifier circuit was tested at 77 K, and these results are compared with those from the hybrid amplifier

Determination and Correlation of Anticardiolipin Antibody with High Sensitivity C- reactive Proteins and its Role in Predicting Short Term Outcome in Patients with Acute Coronary Syndrome

Anticardiolipin antibody (aCL) is considered to be an independent risk factor while high sensitivity C reactive protein (hsCRP) is an established marker for coronary artery disease. This study was conducted to determine levels of aCL antibodies and hsCRP, their correlation and role in predicting recurrence of events in patients presenting with Acute Coronary Syndrome (ACS). Sixty patients admitted with Acute Coronary Syndrome were followed up for 7 days or until discharge. Patients were classified into two groups as those having experienced an ischemic event needing intervention within 7 days (Group I) and other having an event free recovery (Group II). aCL antibody and hsCRP levels were estimated and compared in these two groups. Twenty age and sex matched disease free persons served as controls. The levels of aCL were significantly higher in patients with ACS as compared to the controls (p=0.020). However the levels of aCL in Group I (13.39±9.46 GPL-U/ml) and Group II (13.51±9.93 GPL-U/ml) were not significantly different (p =0.838). The mean hsCRP levels were higher in cases with an event (23.30±10.68 mg/dl) than in cases without an event (20.60±11.45mg/dl) though it was not significant statistically (p=0.389). aCL and CRP were not found to be significantly correlated in causing the recurrence of events(p=0.178). Therefore anticardiolipin antibody is an independent risk factor which could be implicated in the pathogenesis of ACS. However it is not significantly associated with recurrence of short-term events in patients with ACS. Also, aCL antibody does not have significant correlation with hSCRP in causing recurrence of events in the patients of acute coronary syndrome

Optimization Problem of Mortar Barrel and Bomb Clearances

Optimum mortar windage to achieve maximum accuracy and required velocity for impacting the firing stud under two conditions of constraint is considered. These control constraints are considered to be bounded and the extremals have been studied

Evaluation of Funginil (Trichoderma harzianum Formulation) for the Control of Botrytis Corm Rot (Botrytis gladiolorum) on Gladiolus (Gladiolus hybridus) Varieties

Evaluation of the effect of dipping of corms of gladiolus (Gladiolus hybridus) in three concentrations (0.5; 1.0 and 1.5%) of Funginil (Trichoderma harzianum formulation) against Botrytis gladiolorum isolate BG-4 on the growth and yield parameters of White Enchantress and Sheherzade varieties were carried out in pot culture and under field experiments, respectively. The result of the pot experiment on White Enchantress revealed that there was a highly significant reduction in disease incidence in treatment of Funginil over both the inoculated and uninoculated controls. As the rate of Funginil increased the percentage of sprouting also increased whereas the disease incidence decreased significantly. In the field trial, the maximum plant height, number of leaves, number of spikes, rachis length, and number of floret, length of floret and diameter of first floret were obtained with the application of 1.5% Funginil. The height decreased with the increasing number of the leaves, spikes, floret, length of floret and floret diameters as well as rachis length increased with increasing rates of Funginil. These results suggest that Funginil can be used as biocontrol agent against corm rot (B. gladiolorum) of Gladiolus (Gladiolus hybridus) varieties

Measures of Performance for a Flexible Manufacturing System

A number of measures of performance of flexible manufacturing system, represented by a closed queueing network model are given and the relationships among them have been developed

An Algorithm for Calculating Expected Production Function and other Similar Functions for a Flexible Manufacturing System

The fact that for the case when the number of machines in each group is the same, the expected production function is a symmetric function of scaled workloads, is exploited to express this function in terms of the, basic symmetric functions of the loads. The same technique is suggested for calculating the probability of all the machines being found busy and the variance of the proportion of busy machines in the system

Advanced tracking systems design and analysis

The results of an assessment of several types of high-accuracy tracking systems proposed to track the spacecraft in the National Aeronautics and Space Administration (NASA) Advanced Tracking and Data Relay Satellite System (ATDRSS) are summarized. Tracking systems based on the use of interferometry and ranging are investigated. For each system, the top-level system design and operations concept are provided. A comparative system assessment is presented in terms of orbit determination performance, ATDRSS impacts, life-cycle cost, and technological risk