Asymmetric Nexus Between Monetary Freedom and Economic Growth of Pakistan

This extended abstract is part of the Faculty Research Day 2022

Poverty Alleviation through Corporate Social Responsibility: The Case of Legal Approach in Asian Countries

Extended abstract from Faculty of Business and Law Research Day 202

Identification of Blade-root Joint Dynamics in Turbine Disks

L'abstract è presente nell'allegato / the abstract is in the attachmen

Characterization of degraded drag-reducing polymer solution and its impact on the structure of turbulence

Turbulence is often described in terms of either a random process or interacting coherent structures, which is really a choice of which parts of the turbulence to ignore. Focusing on coherent structures reducing the complexity of the problem, which is required to make flow control a possibility. The primary focus of the current study is to analyze how coherent structures within a turbulent boundary layer are modified with the addition of drag-reducing polymer solution (polyethylene oxide, PEO). The performance is known to be concentration dependent, so to mitigate the impact of concentration gradients within the boundary layer the study was performed within a homogeneous polymer ocean. However, this requires the PEO to be exposed to a pump that is known to cause mechanical degradation via chain scission, which significantly impact the polymers behavior. Thus mechanical degradation of dilute PEO solutions was investigated with a turbulent pipe flow setup. Comparative analysis between degraded and non-degraded PEO samples at the same mean molecular weight showed that deviations in the polymer performance scaled with the normalized difference between the initial and final molecular weights. Furthermore, based on literature as well as the current results it was shown that the polymer performance deviations are most likely related to changes in the molecular weight distribution. It was also shown that these deviations could be minimized by increasing the residence time. Limiting the turbulent boundary layer operation conditions to the range where it was shown that the degradation had negligible impact on the PEO performance, allowed a detailed study of the impact of the polymers on the turbulent boundary layer coherent structures. It was observed that the anisotropy of the flow scales increases in proportion to drag reduction, which is consistent with the anisotropy of the fluctuating velocity scales observed in the literature

Role of N-Acetylcysteine in Clearance of Secretions in Mechanical Ventilated Patients

Objective: To determine the role of nebulized N-acetylcysteine in mechanical ventilation in clearing the airway of these patients Study Design: A Randomized Control Trial. Place and Duration of Study: Department of Anaesthesia and Intensive Care Unit Nishtar Medical University Hospital and Jinnah Hosptal, Lahore. From January 2017 to July 2018. Material and Methods: In this project total 50 patients were enrolled by consecutive sampling who remained on mechanical ventilation for more than 24 hours and were between ages 15 to 80 years old. Written consent of this project was taken from relative of each patient. These patients were divided into two groups by lottery method into case and control. The case group received 2 ml of NAC 20% with 8 ml normal saline 3 times a day for 1 day. The control group only received 10 ml normal saline via their nebulizers 3 times a day at 8 AM, 2 PM, and 9 PM. Data was collected and was analyzed. SPSS 22 was used for this purpose. All numerical variables of this research such as mean FiO2, mean peak and plateau pressure of airway, mean blood pressure, mean age and importantly mean density of secretions were calculated. In these values t test was applied and p value was calculated. If it was less than .005, then it was considered significant. Similarly, qualitative data such as type of disease were calculated in percentage and chi square test was used to check the significance. Results: The mean O2 saturation of baseline, 12 hours and 24 hours of the controls was 93.84±2.28, 94.27±2.33 and 94.08±1.81 respectively. The mean peak airway pressure of baseline, 12 hours and 24 hours of the controls was 23.16±3.49, 25.38±8.86 and 24.01±4.91 respectively. The mean plateau airway pressure of baseline, 12 hours and 24 hours of the controls was 19.04±7.79, 21.37±4.86 and 21.85±8.93 respectively. The mean secretion density of baseline, 12 hours and 24 hours of the controls was 1.04±0.024, 1.05±0.03 and 1.03±0.002 respectively. While, the mean O2 saturation of baseline, 12 hours and 24 hours of the cases was 93.08±2.37, 94.61±2.56 and 94.11±2.34 respectively. The mean peak airway pressure of baseline, 12 hours and 24 hours of the cases was 26.58±5.81, 23.81±8.28 and 24.34±6.15 respectively. The mean plateau airway pressure of baseline, 12 hours and 24 hours of the cases was 21.88±78.01, 24.88±6.67 and 23.51±7.55 respectively. The mean secretion density of baseline, 12 hours and 24 hours of the cases was 1.01±0.021, 1.08±0.022 and 1.008±0.0195 respectively. The differences were statistically insignificant. P-value ≤ 0.05 is considered as significant. Conclusion: It is concluded from our observations that use of N-acetylcysteine in patients on mechanical ventilation is very effective in clearance of secretion and to maintain airway clear. Key words: N-acetylcysteine, mechanical ventilation, airway clearance, normal saline DOI: 10.7176/JMPB/54-07 Publication date: April 30th 201

Relationship of platelet-lymphocyte ratio with severity of obstructive sleep apnea syndrome.

Objective: Objective of study was to assess the inflammation in obstructive sleep apnea syndrome patients by using platelet lymphocyte ratio and relationship between platelet lymphocyte ratio and severity of obstructive sleep apnea. Study Design: Cross sectional study Place and Duration: Pulmonology department of Nishtar Hospital Multan and Jinnah Hospital, Lahore  from June 2018 to March 2019. Methods: This cross sectional study was conducted in Pulmonology department of Nishtar Hospital Multan from June 2016 to March 2017.Total 280 patients were selected by non-probability consecutive sampling. All patients underwent whole night polysomnography. Patients were divided into control group (AHI <5), mild OSAS group (AHI 5-15), moderate OSAS group (AHI 15-30) and sever OSAS group (AHI >30) according to their AHI score. Numerical variables like age, body mass index, white cell count, platelets, hemoglobin (Hb) and platelet lymphocyte ratio were statistically analyzed by mean and standard deviation and t-test applied to assess their significance. Qualitative variables like gender and smoking status were statistically analyzed by frequency and percentage. Chi square test was applied to check the significance. P value <0.05 was regarded as significant. Results: Platelet lymphocyte ratio was significantly raised in patients with obstructive sleep apnea syndrome. There was significant correlation between platelet lymphocyte ratio and AHI (p<0.05). So study showed that there was significant association between obstructive sleep apnea syndrome severity (represented by AHI) and systemic inflammation (represented by PLR). Significant differences were found between age (p =0.000), ESR (p =0.000), CRP (p =0.003), Cholesterol (p =0.000), Platelets (p =0.048), Hb (p =0.000), PLR (p =0.000) and white blood cells (p =0.000), in groups. Association was found between gender (p =0.000) and smoking status (p =0.030) in groups. So, gender and smoking were the effect modifiers. Conclusion: the observations of our study suggest that Platelet lymphocyte ratio was significantly raised in patients with obstructive sleep apnea syndrome. There was significant correlation between platelet lymphocyte ratio and AHI (p<0.05). So study showed that there was significant association between obstructive sleep apnea syndrome severity (represented by AHI) and systemic inflammation (represented by PLR). Key words: Obstructive sleep apnea syndrome, Platelet lymphocyte ratio, polysomnography DOI: 10.7176/JMPB/54-08 Publication date: April 30th 201

Hybrid Numerical-Experimental Model Update Based on Correlation Approach for Turbine Components

Bladed-disks in turbomachines experience high cycle fatigue failures due to high vibration amplitudes. Therefore, it is important to accurately predict their dynamic characteristics including the mechanical joints at blade-disk interfaces. Before the experimental identification of these joints, it is of paramount importance to accurately measure the interface degrees-of-freedom (DoF). However, they are largely inaccessible for the measurements. For this reason, expansion techniques can be used in order to update the single components. But the expansion can be affected adversely if the measurements are not properly correlated with the updated model. Therefore, a frequency domain expansion method called System Equivalent Model Mixing (SEMM) is used to expand a limited set of measurements to a larger set of numerical DoF. Different measured models—termed the overlay models—are taken from an impact testing campaign of a blade and a disk and coupled to the numerical model according to the SEMM. The expanded models—termed the hybrid models—are then correlated with the validation channels in a round-robin way by means of Frequency Response Assurance Criteria (FRAC). The global correlations depict whether or not a measurement and the respective expansion is properly correlated. By this approach, the least correlated channels can be eliminated from the measurements to have a better updated hybrid model. The method is tested on both the structures (the blade and the disk) and it is successfully shown that removing the uncorrelated channels does improve the quality of the hybrid models

A DELAYED FREQUENCY PRECONDITIONER APPROACH FOR SPEEDING-UP FREQUENCY RESPONSE COMPUTATION OF STRUCTURAL COMPONENTS

In this work, a delayed frequency preconditioner (DFP) is developed and applied in structural problems for speeding-up the frequency response computation. The challenge of computing the frequency response lies in the computation of the linear system that involves the excitation forces and also the dynamic stiffness which is frequency-dependent. For each frequency, the dynamic stiffness must be updated and a new factorization must be performed, which introduces a high computational cost on the solutions of the linear systems. Alternatively, iterative solver such as GMRES can be applied to avoid the cost of factorization, however they require good preconditioners that are traditionally also frequency-dependent. In the new approach, the dynamic stiffness operator is updated with the frequency whereas the preconditioner is kept constant for a range of frequencies serving as a low-cost preconditioner for the iterative solver. This technique saves computation time because a new factorization is avoided for each frequency point. On the other hand, the effectiveness of the delayed preconditioner is destroyed when the frequency of the dynamic operator is too far away from each other. Therefore, we propose a heuristic approach to update the preconditioner when it is underperforming. The algorithm is tested on structural problems and the results show that this approach can drastically reduce the number of iterations for the computation of the frequency response