18 research outputs found
Presenting signs and symptoms of ovarian cancer at a tertiary care hospital
Objective: To identify early warning signs and symptoms of ovarian cancer to create awareness for early diagnosis and management of the disease.Methods: This study was conducted at the department of Gynaecology and Obstetrics, Liaquat National Hospital, Karachi from 2003 to 2007, having 75 patients. The information collected included age, education, and self perceived state of socio-economic class, presenting clinical signs and symptoms, basic and specific laboratory investigations. The disease was staged from I to IV upon surgical staging and the type of cancer was determined by histopathological examination.Results: Mean age of the patients was 51 +/- 12.3 years. Twenty (52%) patients were uneducated, 17 (22.6%) were below and remaining 19 (25.3%) were above higher secondary level. Most of the patients belonged to the middle socioeconomic class. Abdominal pain (57.3%) was the most common presenting symptom followed by abdominal distension (22.6%), urinary complaints (5.3%), vaginal discharge (2.6%) and postmenopausal bleeding (12%). More than half (56%) of the patients had stage III-IV disease. On histology, papillary serous cystic adenocarcinoma was the most common (54%) type followed by mucinious (22%), endometroid (10.6%), yolk sac (2.6%), dysgerminoma (4%), and adult granulose cell tumour (5.3%).Conclusion: There are no specific ovarian carcinoma symptoms either in early or late stages to ensure early diagnosis, but in the age group above 40 years persistent clinical symptoms should always be further investigated
Cfd Simulation To Study The Effects Of Ribs In A Converging Nozzle Flow At Sonic Mach Number
The presence of a blunt base leads to flow separation in aerodynamic bodies,
which causes a low-pressure in the wake region. At sonic Mach number, low pressure
in the wake region contributes up to sixty percent of the total drag. This study is
conducted to study the effect of the rectangular ribs on the base pressure. The
parameters considered are the nozzle pressure ratio, rib’s aspect ratio, Length to
Diameter (L/D) ratio of the duct when placed circumferentially operating from
subsonic to sonic Mach number. The simulation is performed using CFD, and the k-ɛ
turbulence model is employed. Initially, the simulation results obtained are validated
with experimental work for different L/D ratio of the duct at various Nozzle Pressure
Ratio’s (NPR), and the aspect ratio of the ribs from 3:1 to 3:3 for area ratio of 6.25.
The results are in good agreement with the experimental results. Later simulations are
done for a single rib, which is placed at different locations and aspect ratios for NPRs
in the range from 1.5 to 5 from the base. Base pressure variations, velocity, and
pressure field changes for the above variables are discussed. The simulation results
indicate that the rib breaks the primary vortex at the base and form multiple vortices
and hence controls the base pressure in the wake region. The results show that a
rectangular rib with a lower aspect ratio is effective in reducing the base pressure,
whereas the rib with a higher aspect ratio tends to increase the base pressure. The
simulations are also conducted for a duct with a diameter, D = 20 mm. In this case, the
rectangular rib with aspect ratios 3:1, 3:2, and 3:3 is placed at 20 mm, 40 mm, 60 mm,
and 80 mm locations, for the same NPRs. Results show that the height and position of
the rib plays a vital role in controlling the base pressure
Job satisfaction leading to organizational excellence : a case study on expatriate academicians in Malaysian public universities
The purpose of this descriptive, co-relational and cross-sectional research was to gain a better understanding of the job satisfaction for the expatriate academicians working in Malaysian public sector universities which in turn leads to organizational excellence. Data were collected by the distribution of two same set of questionnaires comprising of total 73 questions which were divided in to 5 categories. One set of questionnaire was distributed among 50 expat academicians working in International Islamic University Malaysia (IIUM), in Kuala Lumpur and the other set of questionnaire was again distributed among 50 expat academicians working in Universiti Sains Malaysia (USM), located in Nibong Tebal, Penang. The results of the paper indicate that expat academicians working in Malaysian public sector universities are moderately satisfied with their jobs and committed to their organization. Employees' job satisfaction and organizational commitment were closely interrelated using intrinsic, extrinsic parameters. Strong correlation between intrinsic parameter and job satisfaction leading to organizational excellence was expected, but there was also unexpected correlation with respect to work force, work values, attitude and behaviour (WWAB) parameter. The whole research revolves around intrinsic, extrinsic and WWAB parameter so as to understand the scope of job satisfaction among the expat academicians working in Malaysian public sector universities which in turn affects organisational excellence. As job satisfaction and organizational commitment are strongly correlated, therefore it is very important to understand the parameters which impact them
CFD analysis of convergent-divergent nozzle flow and base pressure control using micro-JETS
This paper presents numerical study was undertaken to identify the use of the micro-jets to regulate the pressure in the region from two-dimensional convergent-divergent (CD) Nozzle. At the exit of the divergent nozzle in the base region 1 mm of two micro-jets orifice diameter has been arranged at ninety degrees at pcd 13 mm to control base pressure. The inertia level at the inlet to suddenly expanded duct was 1.87. The micro-jets are suddenly expanded into a two-dimensional planar area ratio of 3.24. The L/D of the duct was 1, 2, 4, 5, 6, 8 and 10. The total wall pressure distribution from inlet to the outlet too was recorded. The results indicate that the micro-jets can oblige as the effective regulators of the pressure in the base area. The duct wall pressure field is not negatively affected by the dynamic control. Nozzles were operated with the NPR in the range from 3 to 11. The results show that we can fix the flow parameter which will result in the maximum gain in the base pressure, velocity and temperature. The convergent-divergent nozzle geometry has been modeled and sim-ulated employing turbulence models: K-ε standard wall function turbulence model from the code was validated with the commercial com-putational fluid dynamics
Experimental investigation of suddenly expanded flow at sonic and supersonic Mach numbers using semi-circular ribs: a comparative study between experimental, single layer, deep neural network (SLNN and DNN) models
DATA AVAILABILITY: The datasets generated during and/or analyzed during the current study are available from the corresponding author on
reasonable request.In this work, we present the findings of the experimental study conducted in a rectangular duct at sonic and supersonic Mach numbers using passive control in the form of semi-circular ribs. Tests are conducted at sonic Mach number and four supersonic Mach numbers. The supersonic Mach numbers of the study are 1.5, 1.8, 2.2, and 2.5. The flow from the nozzles is discharged into the enlarged duct. The ribs are placed at 28 mm (1D), 56 mm (2D), 84 mm (3D), and 112 mm (4D) from the base to find the effect of the control mechanism on the flow field and the base pressure. The ribs of 6, 8, and 10 mm diameter are used to control the base pressure and ultimately the base drag. At Mach 2.2 and 2.5, control is not effective because the nozzles are over-expanded. These results reiterate the findings from the literature that the control is effective whether passive or active when nozzles flow under the influence of a favorable pressure gradient. The same is evident from the results at Mach 1.5 and 1.8. The NPRs at these Mach numbers are such that nozzles are under, correctly, and under expanded. When nozzles are operated for under expanded case, the control results in an increase in the base pressure when passive control is employed. These highly complex data are predicted using a single-layered neural network and a deep-layer neural network to save time and make it cost-effective, which shows that the data can be predicted with an accuracy of 0.88–0.99. The proposed models can predict the highly sensitive pressure terms for aerodynamic flows.This research was funded by Universiti Sains Malaysia. APC was funded by Universiti Sains Malaysia.https://www.springer.com/journal/13360Mechanical and Aeronautical Engineerin
Numerical simulation of suddenly expanded flow at Mach 2.2
A numerical simulation has been performed to investigate the control of base pressure with microjets in a suddenly expanded duct. Microjets placed at the pitch circle diameter (PCD) of 13 mm, two micro jets of 1 mm orifice diameter located at 900 for active control. The flow Mach number of the investigation was M = 2.2, the L/D ratio of the enlarged duct considered is 6, and the area ratio is 3.24. The convergent-divergent (CD) nozzle geometry has been modeled and simulated employing K-ε turbulence model for standard wall function. From the code independently was checked with the commercial computational fluid dynamics software. The numerical simulations carried for nozzle pressure ratio’s (NPR) 3, 5, 7, 9 and 11. From the present numerical investigation, it is observed that the NPR, Mach number, and area ratio plays a vital role in fixing the base pressure values. NPR's of the present study is such that the flow mostly remained over expanded. Despite jets being over-expanded the control is effective in decreasing the base suction and hence the base drag
The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy
Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations.
Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves.
Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p 90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score.
Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
Job satisfaction leading to organizational excellence : a case study on expatriate academicians in Malaysian public universities
The purpose of this descriptive, co-relational and cross-sectional research was to gain a better understanding of the job satisfaction for the expatriate academicians working in Malaysian public sector universities which in turn leads to organizational excellence. Data were collected by the distribution of two same set of questionnaires comprising of total 73 questions which were divided in to 5 categories. One set of questionnaire was distributed among 50 expat academicians working in International Islamic University Malaysia (IIUM), in Kuala Lumpur and the other set of questionnaire was again distributed among 50 expat academicians working in Universiti Sains Malaysia (USM), located in Nibong Tebal, Penang. The results of the paper indicate that expat academicians working in Malaysian public sector universities are moderately satisfied with their jobs and committed to their organization. Employees' job satisfaction and organizational commitment were closely interrelated using intrinsic, extrinsic parameters. Strong correlation between intrinsic parameter and job satisfaction leading to organizational excellence was expected, but there was also unexpected correlation with respect to work force, work values, attitude and behaviour (WWAB) parameter. The whole research revolves around intrinsic, extrinsic and WWAB parameter so as to understand the scope of job satisfaction among the expat academicians working in Malaysian public sector universities which in turn affects organisational excellence. As job satisfaction and organizational commitment are strongly correlated, therefore it is very important to understand the parameters which impact them
Numerical investigation of turbulence models with emphasis on turbulent intensity at low Reynolds number flows
The primary goal of this research is to investigate flow separation phenomena using various turbulence models. Also investigated are the effects of free-stream turbulence intensity on the flow over a NACA 0018 airfoil. The flow field around a NACA 0018 airfoil has been numerically simulated using RANS at Reynolds numbers ranging from 100,000 to 200,000 and angles of attack (AoA) ranging from 0° to 18° with various inflow conditions. A parametric study is conducted over a range of chord Reynolds numbers for free-stream turbulence intensities from 0.1 % to 0.5 % to understand the effects of each parameter on the suction side laminar separation bubble. The results showed that increasing the free-stream turbulence intensity reduces the length of the separation bubble formed over the suction side of the airfoil, as well as the flow prediction accuracy of each model. These models were used to compare the modeling accuracy and processing time improvements. The K- SST performs well in this simulation for estimating lift coefficients, with only small deviations at larger angles of attack. However, a stall was not predicted by the transition k-kl-omega. When predicting the location of flow reattachment over the airfoil, the transition k-kl-omega model also made some over-predictions. The Cp plots showed that the model generated results more in line with the experimental findings
Photoreduction of 4-Nitrophenol to 4-Aminophenol Using CdS Nanorods
In this study CdS nanorods (NR), of 46.6 nm average length and diameter ≥3.30 nm (TEM), derived from cadmium(II) dibenzylcarbamodithioate have been used as a visible light driven photocatalyst for the transformation of environmentally detrimental 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) of pharmaceutical significance. As prepared CdS-NR were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), selected area electron diffraction technique (SAED), fourier transmission infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS), steady-state and time resolved photoluminesce (PL) and UV-visible spectroscopy (band gap of 2.4 eV). PXRD results revealed that CdS-NR exhibit pure hexagonal character. The photoluminescence and time-resolved PL have confirmed the low electron–hole recombination rate in CdS-NR than the bulk CdS. The transformation of 4-NP to 4-AP on CdS-NR follows pseudo-first order kinetics with a rate constant 0.202 min−1 and turnover frequency (TOF) 6.06 h−1