Flow quality improvement of the wind tunnel testing for a highly-loaded compressor cascade at high incidence

To obtain reliable and accurate experimental data in cascade testing, the influencing factors and the improving method of the flow quality of a highly-loaded compressor cascade under high incidence were investigated through a series of numerical simulations and experiments. The numerical method was validated by experimental data and agreed well at both incidence angles of 0° and 6°. Under the original upper end wall, both experimental and numerical results indicated an unsatisfactory flow quality of the cascade with an obvious nonuniformity of inlet Mach number, and the incidence of the central blade is 3.6° larger than the theoretical value. Using a small curved upper wall can reduce the severe flow separation on the upper wall and achieve a maximum improvement in flow quality under the critical installation angle, where the incidence deviation of the central blade was reduced to 2.1°. Using the combination of adjustable tailboards and a small curved upper end wall can further improve the cascade flow quality. Under the optimal angle of the tailboards, both the inflow uniformity and the outflow periodicity of the three middle blade passages the test requirements, and the incidence deviation of the central blade is reduced to 0.2°.

Optical Coherence Tomography Angiography Predicts Visual Outcomes for Craniopharyngioma in Children by Quantifying Choroidal Capillaries

Purpose: To predict the prognosis of craniopharyngioma in children by optical coherence tomography angiography (OCTA).Methods: We evaluated if the relationship between preoperative OCTA of the choroidal capillary density (CCD) and visual outcome continued over long-term visual recovery in 38 patients undergoing craniopharyngioma resection. Patients were evaluated 3 times: 1 week before surgery (Visit1), followed-up at 6–10 weeks (Visit2), and 9–15 months (Visit3) after surgery.Results: In total 38 patients (70 eyes) with craniopharyngiomas, which included 20 (52.6%) boys and 18 (47.4%)girls, the mean age was 11.8 ± 2.7 years (range: 6–18 years). The age (p = 0.71), gender (p = 1.00), mean refractive error (p = 0.55), and axial length (p = 0.23) of 38 normal volunteers (76 eyes) were matched. After surgery, the cross-compression of patients was relieved. The average visual acuity change in the normal CCD group was 0.07 ± 0.02; the average visual acuity change in the low CCD group was 0.01 ± 0.01, p < 0.001. Preoperative CCD value is related to the preoperative BCVA (p < 0.001), and the visual function after the long-term follow-up (9–15 months) (p < 0.001). The prognosis of CCD has the same trend as the BCVA. Further correlation analysis shows that CCD and BCVA are significantly correlated (r = 0.878; p < 0.001). CCD has a weak but significant correlation both with MD (r = 0.19; p < 0.001) and PSD (r = −0.21; p <0.001). A natural cutoff of CCD is approximately 38%. With the normal CCD group the maximum improvement of BCVA exceeds 0.3 post-operatively, compared to eyes in the low CCD group that improve by <0.03, and worse after surgery.Conclusions: Long-term vision recovery after surgical decompression of craniopharyngiomas in children can be predicted by preoperative by OCTA. Patients with normal CCD before surgery showed a tendency to improve vision; this trend of improvement persisted in subsequent follow-ups. The CCD baseline natural cutoff value for predicting visual prognosis before and after surgery is about 38%.

A clinical trial comparing BiVap (Richard Wolf®) saline vaporization of the prostate vs. TwisterTM Diode Laser System in the treatment of benign prostatic obstruction between prostate volume 90 to 150 ml

Introduction To evaluate the efficacy, safety and postoperative outcomes of the BiVap and Twister systems with benign prostatic obstruction (BPO) in prostate volüm between 90–150 ml. Methods In total, we included 131 patients treated with BiVap system (n = 68) and Twister system (n = 63). Postoperative complications including urinary tract infection, transient hematuria, severe dysuria and fever >38° C, urinary incontinence and urethral stricture were also noted. All patients were evaluated at the postoperative 1st, 3rd, 6th and 12th month and preoperative and postoperative values of IPSS score, QoL score, total PSA, IIEF 15, PVR, Qmax and Qave were compared. Results Preoperative demographic characteristics were similar in the 2 groups. There was observed significant improvement for IPSS, Qmax, Qave, PVR, and QoL score by the postoperative first month compared to the preoperative values in both groups. Maximum improvement in the IPSS, Qmax, Qave, QoL score and PVR were achieved at postoperative 6, 3, 12, 3 and 12th months respectively in group 1. In group 2 maximum improvement in the same parameters were achieved at postoperative 6, 3, 6, 6 and 12th months, respectively. Conclusions BiVap and Twister systems are safe, effective, and useful technique, which can be used in the surgical treatment of BPO between 90–150 ml.

Surface Modification of Commingled Flax/PP and Flax/PLA Fibres by Silane or Atmospheric Argon Plasma Exposure to Improve Fibre–Matrix Adhesion in Composites

Challenges faced by natural fibre-reinforced composites include poor compatibility between hydrophilic fibres such as flax and hydrophobic polymeric matrices such as polypropylene (PP) or poly(lactic acid) (PLA), and their inherent flammability. The former promotes weak interfacial adhesion between fibre and matrix, which may be further compromised by the addition of a flame retardant. This paper investigates the effect that the added flame retardant (FR), guanylurea methylphosphonate (GUP) and selected surface treatments of commingled flax and either PP or PLA fabrics have on the fibre/matrix interfacial cohesive forces in derived composites. Surface treatments included silanisation and atmospheric plasma flame exposure undertaken both individually and in sequence. 1-, 2- and 8-layered composite laminates were examined for their tensile, peeling and flexural properties, respectively, all of which yield measures of fibre-matrix cohesion. For FR-treated Flax/PP composites, maximum improvement was obtained with the combination of silane (using vinyltriethoxysilane) and plasma (150 W) treatments, with the highest peeling strength and flexural properties. However, for FR-treated Flax/PLA composites, maximum improvement in both properties occurred following 150 W plasma exposure only. The improvements in physical properties were matched by increased fibre-matrix adhesion as shown in SEM images of fractured laminates in which fibre-pullout had been eliminated.

EFFICACY OF AABHADI CHURNA ALONG WITH PATHYA AAHARA AND VIHARA IN GRIDHRASI W.S.R. TO SCIATICA - A RESEARCH ARTICLE

Nowadays due to changing lifestyle, lack of physical activity and long sitting postures lead to a disease called Gridhrasi. Symptoms of Gridhrasi closely resemble the clinical features of Sciatica. Sciatica is a severely painful condition where the sciatic nerve of one or both legs is involved. This study was undertaken to evaluate the clinical efficacy of Aabhadi Churna along with Pathya Aahara and Vihara in Gridhrasi with special reference to Sciatica. The study was conducted on 60 patients who fulfilled the diagnostic and inclusive criteria of sciatica. The clinical assessment was based on subjective parameters (Ruka, Stambha, Toda, Spandana) and objective parameters (Straight leg raising test, standing time and walking time). The subjective and objective parameters before and after treatment were analyzed by using the student "t" test. The t-test results were highly significant for both the groups when the therapy effect was compared before and after the treatment. The inter-group comparison showed that the Group-B treatment method where 84% of patients showed moderate to maximum improvement method was better when compared to Group-A where this percentage was 67% only. Keywords: Gridhrasi, Sciatica, Pathya Aahara, Vihara, Aabhadi Churna.

A Study on a Modified Model for the Hold Time of a Clean Extinguishing Agent

When estimating the theoretical hold time of a Clean Extinguishing Agent (CEA), the hold time is predicted using a leakage exponent and leakage characteristics that are measured through an Enclosure Integrity Test (EIT). In particular, the leakage exponent n is conventionally applied as 0.5, but recently, a variable exponent has been applied through measurement (approximately 0.48 to 0.85). When variable n is applied, the hold time varies greatly depending on the size of n. Therefore, in this study, a modified theoretical model for the hold time of a CEA is proposed to improve the accuracy of the hold time depending on the leakage exponent n. The modified theoretical model applies a different analysis of the inflow and outflow volumetric flow, and the results enable a more accurate hold time prediction. The modified theoretical equation shows an improvement of up to 8.6% for outflow volumetric flow V˙o and a maximum improvement of approximately 10.7% for hold time th.

Flow and Heat Transfer of Supercritical Co2 in a Vertical Tube Under Ocean Rolling Motion

In order to explore the fluid flow and heat transfer features of supercritical fluids used in Brayton cycle for waste-heat utilization of marine gas turbines, the effects of ocean rolling motion on thermo-fluidic characteristics of supercritical carbon dioxide (SCO2) in a circular tube are computationally investigated based on a verified turbulence model. It can be found that at a given rolling period, compared to that under static condition, the time-averaged heat transfer capacity is improved by 7.9%, but the onset of the heat transfer recovery is delayed so that the range of the heat transfer deterioration becomes widened. Under the action of the inertial forces, the heat exchange between cooler/denser and warmer/lighter fluids is enhanced, a secondary circulation formed at t/tc = 0.325 and the maximum improvement of section-averaged heat transfer coefficient is 71% at this time. For various periods, the variation trend of time-averaged heat transfer coefficient for SCO2 shows a parabolic, which is distinguishing from conventional fluids. A polarization phenomenon for instantaneous thermal performance can be observed under severe rolling. With rise of the layout height, the time-average heat transfer performance of tube increases monotonously, and the maximum increment is 10.64% in study range.

Dysphagia intervention in NICU set up: a report of case studies in an Indian public hospital

<p class="abstract">A retrospective study was conducted in the Neonatal Intensive Care Unit (NICU) of a public hospital in Mumbai, India wherein 13 neonates with varying pathophysiologies were taken up for swallowing intervention. Of these, 7 neonates had history of prematurity, 1 was born of twin birth with prematurity, 3 had clefts of lip/palate and 2 had Pierre Robin Syndrome. For 7 neonates with prematurity, the swallowing regimen consisted of oro motor intervention (OMI) followed with therapeutic oral feeds. With improved tolerance of oral feeds while maintaining airway safety, they were graduated to oral feeds progressively increasing in volume until they reached optimum prescribed oral feeds. 6 out of 7(86%) progressed to breast feeds while1 succumbed to medical complications. 3 babies with CLP graduated to complete oral feeds through bondla, when they were fitted with obturators and had swallowing intervention but were unable to move to breastfeeds while in NICU. 2 babies with PRS could not tolerate oral feeds even after multiple sessions and had to be maintained on orogastric feeds. 1 infant, one of a twin delivery with prematurity although was showing improvement to OMI succumbed to medical complications. Among these neonates, those with prematurity showed the maximum improvement with swallowing intervention followed by infants with CLP. Co-morbidities such as prematurity in twin births worsened the prognosis as did a disorder such as PRS. This preliminary study, done on a small sample, stressed the importance of swallowing intervention in neonates with high risk factors by the SLP in the NICU in an Indian set up. </p>

Active Flow Control over a NACA23012 Airfoil using Hybrid Jet

A time-dependent numerical simulation is performed to examine the flow separation control with the action of a hybrid jet (the combination of synthetic and continuous jets) over a NACA23012 airfoil. The unsteady Reynolds-averaged Navier–Stokes (URANS) simulation is performed with Spalart-Allmaras (SA) turbulence model to simulate the flow field around the airfoil to analyse the effect of the hybrid jet. A combined jet is placed at the point of flow separation on the upper surface of the airfoil which is located at the 12% of the chord length from the leading edge of the airfoil for a given flow configuration. Flow simulations are performed at a chord-based Reynolds number of 2.19 × 106 for the hybrid jet oscillating frequency of 0.159 at a blowing ratio of 3.0. The contribution of the continuous jet in the hybrid jet is evident by the flow control. Variation in the continuous jet velocity is studied, which improved the aerodynamic characteristics of the airfoil. The maximum improvement in lift to drag ratio is observed from 11.19 to 22.14 at an angle of attack of 22 degree. The stall angle also shows an enhancement from 18 degree to 20 degree.

Ground Improvement By Using Coir Geo-Textile

For the design of pavement structure the subgrade soil and its properties are important as it gives adequate support to the pavement. To increase the life of pavement the subgrade must be able to support loads transmitted from pavement structure without excessive deformation under adverse climatic and traffic conditions. For using the soil as a good quality pavement material, it is a well-known fact that all soils do not possess all the desirable qualities. The subgrade performance of such soils should be increased by several modification techniques, when such soils cannot be replaced. Among that providing reinforcement to improve subgrade soil nowadays is widely adopted. Nowadays many reinforcing techniques are used to reinforce the soil, among that coir geotextile is most widely used. As it is a natural geotextile it needs treatment to improve the durability. In this study woven coir geotextile are used as soil reinforcement to improve the subgrade soil. The improvement in CBR value when coir geotextile placed at different depth in CBR mould is studied. The coir geocells with an aspect ratio of 0.75, 1 and 1.33 is used. The maximum improvement in CBR value is obtained when geotextile is placed at 1/3H. The CBR value improved when treated coir geotextile is used and the percentage improvement is 66.8% for coir geotextiles placed 1/3H and the percentage increase for treated coir geocells when placed at 1/3H is 37.5%. The optimum height of coir geocells is obtained at an aspect ratio of 1.