The computation of stiffness derivative for an ogive in the hypersonic flow

Expression for Stiffness derivative for an Ogive is derived with the suppositions of the arc on the nose of the cone from the air is being considered as perfect gas and the viscosity being neglected, the motion is quasi-steady, and the nose deflection angle of the Ogive θ is in such a way that the M2 after the shock is > 2.5. It is seen that due to the increment in angle θ, the stiffness derivative increases linearly due the progressive increase in the plan form area of the nose shape. The results indicate that there is a 38 percent increase in the stability derivative when the flow deflection θ was enhanced in the range of 5 to 10 degrees. With the further enhancement in the flow deflection angle θ from ten degrees and above, does not yield substantial increase in the stability derivative. Due to this change in the surface pressure distribution will lead to shift the location of centre of pressure, from the hinged position h = 0.5 to 0.8. The centre of pressure also has shifted towards the downstream, which lies in the range from h = 0.72 to 0.85

Reliability Of Transvaginal Ultrasound Measured Endometrial Thickness In Diagnosis Of Endometrial Cancer In Postmenopausal Women

Abstract Objective: Dilatation and curettage have been replaced by ultrasound measurement of uterine endometrial thickness (ET) especially by Transvaginal ultrasound (TVS) as a first step in the workup of women with postmenopausal bleeding for many years. Still, there is no unanimity for endometrial thickness cut-off value to define abnormality. We used an endometrial thickness of 4mm as a cut-off value in this study. Methods: This cross-sectional validation study included 120 patients who presented with postmenopausal bleeding in OPD of POF hospital from 01-12-2017 to 1-06-2018.TVS measured endometrial thickness ≥4mm was assumed positive for malignancy and ˂ 4 mm was taken negative for malignancy. The TVS findings of patients were compared with the histopathology report of endometrial sampling, which was performed in OPD by manual vacuum aspirator (MVA). Histopathology report was taken as a reference standard to confirm or refute the diagnosis of transvaginal ultrasound. Results: On TVS, 54 patients had ≥ 4mm endometrial thickness (taken positive for malignancy) while 66 patients had <4 mm endometrial thickness (taken negative for malignancy). Histopathology of the endometrium (reference standard) revealed that 47 (39.17%) patients had malignancy and 73(60.83%) patients did not have malignancy. The reliability of transvaginal ultrasound (TVS) using 4mm cut-off point ET in detecting endometrial malignancy in patients presenting with uterine bleeding after menopause, keeping histopathological findings as a reference standard showed 89.36% sensitivity, 83.56%, specificity, 92.42% negative predictive value and 77.78% positive predictive value & 85.83% accuracy rate. Conclusion: We concluded that there was a low probability of endometrial malignancy in women with ˂ 4 mm transvaginal ultrasound (TVS)measured endometrial thickness (ET).TVS  may replace invasive endometrial sampling in cases of postmenopausal bleeding with ˂ 4mm ET

Computation of damping derivative of an Ogive at highspeed flow

This paper aims to derive an expression for the damping derivative of an ogive in pitch. The Ogive shape is achieved by superposing an arch on the cone. The inertia levels considered are M = 5, 7, 9, 10, and 15. The contemporary theory applies to the connected shock case & the Mach M2 behind the shock M2 ≥ 2.5. Damping derivatives are examined for ogive for γ = 1.4 at various semi angles for differing pivot positions and Mach numbers and λ = ± 5, 10. Results indicate a continued decrease in stability derivatives. However, the damping derivatives turn independent of Mach M for Mach more than ten— with a surge in the cone angle, a continued rise in the damping derivatives attained

Evaluation of stability derivatives of an Ogive in a Newtonian limit

Stability derivatives for an ogive are obtained in the limiting case of the Mach number when it tends to infinity. The derivative in stiffness declines with the position of the pivot for the whole extent of semi-vertex angles. For half wedge angles from 20 to 25 degrees, there is a thoughtful expansion in the derivative of Stiffness. The derivative of damping declines through the pivot point for different directions of semi-vertex and accomplishes a minimal value at h = 0.75. Afterward, together with expansion in the pivot point, there is an in-direct augmentation in damping derivatives. There is a broad variation in the mathematical worth for more incredible semi-vertex perspectives in the scope of 20 degrees and above. The derivative in Stiffness increases with the angle of the semi-vertex for different varied positions of the pivot. The derivative in damping with the angle of semi vertex for varied fixed positions of pivot supposedly increases directly with the angle of semi vertex. It is additionally seen that this pattern of linear increment will, in general, get non-direct for the angle of the semi vertex in the extent of 20 degrees and past

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

THE USE OF INTERNET BY STUDENTS OF SARGODHA UNIVERSITY

ABSTRACT This study was conducted to examine the trends of using internet by the students of Sargodha University. It also examined the gender difference regarding internet usage. The sample of the data was taken from the University of Sargodha. A survey of 252 students both male and female was randomly selected to participate in the study. The result of the study showed that most of the students of Sargodha University consider internet as a tool for information. They use it for study purposes. They think that internet is an easier way to get information then library. Further, it is recommended that students should be provided with internet at their institutions and they should be given proper education regarding internet usage

Pressure and its derivative with respect to piston Mach number for an oscillating cone

The aim of present study is to obtain mathematical expressions for surface pressure and its derivative with respect to Piston Mach number for an oscillating cone. The effects of Mach number and it’s geometry on Pressure and its derivative with respect to inertia level and incidence angle, and the results have been obtained. The non-dimensional surface pressure distribution on the cone remain linear for lower angle of incidence and Mach number, however, for higher Mach numbers non-linearity creeps in. For higher Mach number due to viscous-inviscid interaction the flow behaves differently. Also, it is observed that there is interaction between the boundary layer and entropy layer and this interaction makes the flow on the surface of the cone very complex. At large Mach numbers the aerodynamic heating will be a serious concern. At high angle theta and low Mach number shock wave will be detached. The surface pressure derivative with Mach number on the cone exhibits linear behaviour for lower Mach number and angle theta and non-linearity for large Mach number and angle theta

Computation of stiffness derivative for an unsteady delta wing with curved leading edges

An attempt has been made to derive the expressions for stiffness derivative for a delta wing with curved leading edges for an unsteady high speed flow. It is evident from the figures that stiffness derivative decreases as Mach number increases. It is also seen that as amplitude of half sine wave increases the stiffness derivative also increases. This is an improvement of previous theory as the effect of leeward surface are included in the present work