Characterising Momentum Flux Events in High Reynolds Number Turbulent Boundary Layers

The momentum flux in a canonical turbulent boundary layer is known to have a time-series signature that is characterised by a highly intermittent variation, which includes very short periods of intense flux activity. Here, we study the variation in these flux signal characteristics across almost a decade of flow Reynolds number (Reτ) by analysing datasets acquired using miniature cross-wire probes with matched spatial resolution. The analysis is facilitated by conditionally sampling the signal based on the quadrant (Qi; i = 1–4) and magnitude of the flux, revealing fractional cumulative contribution from Q4 to increase at a much faster rate than from Q2 with Reτ. An episodic description of the flux signal is subsequently undertaken, which associates this rapid increase in Q4 contributions with the emergence of extreme and rare flux events with Reτ. The same dataset is also used to test Townsend’s hypothesis on the active and inactive components of the momentum flux, which are obtained for the first time by implementing a spectral linear stochastic estimation-based decomposition methodology. While the active component is found to be the dominant contributor to the mean momentum flux consistent with Townsend’s hypothesis, the inactive component is found to be small but non-zero, owing to the non-linear interactions associated with the modulation phenomenon. Finally, an episodic description of the active and inactive momentum flux signal is undertaken to highlight the starkly different time series characteristics of the two flux components. The inactive flux signal is found to comprise individual statistically significant events associated with all four quadrants, leading to a small net contribution to the total flux.

A comparative study on outcome of conservative and surgical treatment of type III supracondylar fracture of humerus in children

<p class="abstract"><strong>Background:</strong> Supracondylar fracture of humerus is most common of all the fractures around the elbow in children. They occur most commonly in children more so in male child with the peak around 5-8 years. Objective of this study was to compare the outcome of 3 different modalities of treatment for supracondylar fracture of humerus.</p><p class="abstract"><strong>Methods:</strong> Children with type III supracondylar fracture of humerus were categorized into group A, group B, group C based on conservative, closed reduction and percutaneous K wire fixation and open reduction and K wire fixation modalities of treatment given. All the children were followed for 6 months and the outcome of treatment was evaluated using Flynn’s criteria.<strong></strong></p><p class="abstract"><strong>Results:</strong> 40 children were treated with 3 different modalities of treatment. The rate of complications was less in children who were operated on first day of admission (p=0.02). Group B and group C had 80% and 61.11% excellent results and group A had 47.05% poor results. The outcome was better with cross K wire pinning than lateral pinning (p=0.015).</p><p class="abstract"><strong>Conclusions:</strong> Supracondylar fracture of humerus should be operated as early as possible to reduce the rate of complications. The outcome of surgical treatment was better than conservative treatment evaluated in terms of Flynn’s criteria. Cross wire pinning was better than lateral pinning in terms of outcome, but the rate of neuropraxias was more with cross wire pinning.</p>

Survey of Interpupillary Distance in Egyptian People

Purpose The aim of this study was to report normative values and ranges of interpupillary distance (IPD) in Egyptian people. Methods This study included 83 healthy subjects; 41 males and 42 females presented with refractive errors to the outpatient clinic of Elshiekh-Zaid specialized hospital in Cairo. After complete ophthalmic evaluation, far IPD measurements were performed using an autorefractometer (Speedy-1, Nikon, Japan), graded ruler (401 A5 stainless hardened, Japan), spectacle frame with two cross-wire lenses (universal trial frame, Carejoy, China). Near IPD measurements were performed using the graded ruler and the spectacle frame. Results Mean age of the study population was 35.1±8.0 years (range 20-50). The mean IPD for far was found to be 64.1±3.7 mm (range 56-72) by autorefractometer (p &lt; 0.001), 63.9±3.7 mm (range 56-72) by PD ruler (p &lt; 0.001), and 62.9±3.7 mm (range 55-71) by frame (p &lt; 0.001). The mean IPD for near was found to be 61.9±3.7 mm (range 54-70) by PD ruler (p &lt; 0.001), and 61.0±3.6 mm (range 53-68) by frame (p &lt; 0.001). The mean IPD value was observed to be significantly higher among males (p &lt; 0.001). Far and near IPD difference by PD ruler was 2.0±0.5 mm (p &lt; 0.001) and by frame was 1.9±0.6 mm (p &lt; 0.001). Conclusion The current study showed normative data on far IPD and near IPD by different methods in Egyptian people. Our study showed that sex and age had significant effects on IPD. Knowledge of normal values in this population may be useful in studying orbito-cranial growth patterns, syndrome diagnosis, surgical management of cranio-facial deformities and trauma, and manufactures of optical frames and lenses.