Diagnostic performance of multidetector computed tomography (MDCT) in diagnosis of sinus variations

Background: In this prospective study, we looked for correlations between anatomic variants of paranasal sinuses and chronic or recurrent sinusitis. Material/Methods: Two hundred and forty (240) patients with clinical features of chronic rhinosinusitis were examined; patients with first-onset or allergic sinusitis and pregnant females were excluded. Routine multi-slice CT of the paranasal sinuses was performed to look for mucosal disease of the paranasal sinuses, drainage pathways, and presence of anatomical variations and their relation to known sinus drainage pathways. Results: Anatomic variations were very frequent, and we classified them into four easily recognized groups: nasal septum variations, middle turbinate variations, uncinate process variations, and ethmoidal variations. Deviated nasal septum was the most frequent variation in patients with chronic or recurrent sinusitis, and it was detected in 48.8% of cases. Agger nasi cells and concha bullosa were equally frequent (30.6%), and Haller cells were detected in 11.2%. Uncinate process variations were detected in 18.1%, and the large ethmoid bulla was detected in 10%. Conclusions: The importance of anatomic variations is that they can compromise drainage pathway of the related sinus, which results in inflammatory sinus disease. Anatomical variations are not diseases on their own and may be present as incidental findings in patient with chronic sinusitis

NUMERICAL PREDICTION OF SOLITARY WAVE FORMATION OF A PLANING HULL IN SHALLOW WATER CHANNELS

This paper uses a CFD (Computational Fluid Dynamics) analysis to investigate the shallow water effects on prismatic planing hull. The turbulence flow around the hull was described by Reynolds Navier Stokes equations RANSE using the k-ɛ turbulence model. The free surface was modelled by the volume of fluid (VOF) method. The analysis was steady for all the range of speeds except those close to the critical speed range due to the propagation of the planing hull solitary waves at this range. In this study, the planing hull lift force, total resistance, and wave pattern for the range of subcritical speeds, critical speeds, and supercritical speeds have been calculated using CFD. The numerical results have been compared with experimental results. The pressure distribution on the planing hull and its wave pattern at critical speed in shallow water were compared with those in deep water

Numerical and experimental investigations on efficient design and performance of hydrokinetic Banki cross flow turbine for rural areas

Micro hydrokinetic energy scheme presents an attractive, environmentally-friendly and efficient electric generation in rural, remote and hilly areas. However, this scheme is yet to be fully discovered, as researchers are still searching for solutions for the main problems of low velocity of current in the open flow channels and low efficiency of hydrokinetic turbines. This research proposes a novel system configuration to capture as much kinetic energy as possible from stream water current. This system, known as bidirectional diffuser augmented (BDA) channel, functions by utilizing dual directed nozzles in the flow and is surrounded by dual cross flow/Banki turbines. It is also important to obtain the efficient design parameters of the turbines to use in the current configuration. The appropriate angle is important in order to guide the flow to touch the blades more perpendicularly to capture as much torque and power as possible. Hence, experimental and numerical investigations have been carried out in this research paper to study the performance characteristics of the CFT configuration applied in BDA system and investigate the effects of blades’ inlet and outlet angles of CFT runners on the internal flow characteristics and efficiency. In this study, four different runners with various inlet and outlet angles of two CFT have been investigated. The CFD results have been validated with the experimental work and proven acceptable with flow pattern and performance characteristics. The results of the current study conclude that the maximum power coefficients (Cp) of 0.612 and 0.473 for lower and upper turbines are recorded for best runner angles of Case 3

Resistance prediction of innovative semi SWATH design concept in shallow water

Many analysis have been conducted to evaluate performance of High Speed Craft (HSC). One of the important analysis is resistance analysis of multihull in shallow water. Ship operating in shallow water experiences increasing of resistance due to change in potential flow and wave pattern. In this paper, shallow water performance has been studied for one type of HSC design concept, Semi SWATH hull form. The hulls are installed with fin stabilizers to reduce dynamic motion effect. Resistance component of the hull, trim and maximum wave amplitude around the hull are obtained from the calm water test in shallow water. These criteria are important in analysing pattern of Semi-SWATH resistance in shallow water flow around hull. The fore fin angle is fixed to zero degree while the aft fin angle is varied for 0, 5, 10 and 15 degree. For each configuration, the investigation is conducted with range of Depth Froude Number from 0.65 to 1.2. From the analysis, it is found that resistance, wave pattern and trim of Semi SWATH is affected by fin angle

A rare case of giant dermoid cyst with ipsilateral paratubal cystadenoma during pregnancy

Dermoid cysts are considered the most common ovarian cysts in adolescents and pregnant women. In rare cases, they can attain a huge size. Paratubal cysts are also common in adolescents. They are usually simple cysts present in the broad ligament. In this case, we report a giant dermoid cyst with ipsilateral paratubal serous cystadenoma discovered during pregnancy of a 20-year-old primigravida. Both cysts were managed conservatively, and then removed successfully at the time of cesarean section by cystectomy

A rare case of giant dermoid cyst with ipsilateral paratubal cystadenoma during pregnancy

Dermoid cysts are considered the most common ovarian cysts in adolescents and pregnant women. In rare cases, they can attain a huge size. Paratubal cysts are also common in adolescents. They are usually simple cysts present in the broad ligament. In this case, we report a giant dermoid cyst with ipsilateral paratubal serous cystadenoma discovered during pregnancy of a 20-year-old primigravida. Both cysts were managed conservatively, and then removed successfully at the time of cesarean section by cystectomy

Application of UPFC to Improve the FRT Capability of Wind Turbine Generator

Variable speed wind turbine generators installation has been significantly increased worldwide in the last few years. Faults at the grid side may call for the disconnection of the wind turbine from the grid as under such events, wind turbine generator (WTG) may not comply with the recent developed grid codes for wind energy conversion systems (WECS). In this paper, a unified power flow controller (UPFC) is applied to improve the fault ride through (FRT) capability of doubly fed induction generator (DFIG)-based WECS during voltage swell and voltage sag at the grid side. Simulation is carried out using MATLAB/Simulink software. Results show that UPFC can effectively improve the FRT capability of DFIG-based WECS and hence maintaining wind turbine connection to the grid during certain levels of voltage fluctuation at the grid side

Comparison of serum cystatin C and creatinine based methods in detection of early renal dysfunction in critically ill patients

Early detection of renal dysfunction is of importance inthe care of critically ill patients. Cystatin C was proposedto be superior to serum creatinine in estimation of renal function. This work aimed to compare serum cystatin Cto serum creatinine and creatinine based formulae indetection of early decline in renal function at a singlepoint in critically ill patients. Fifty critically ill patientsadmitted to Cairo University Hospitals ICUs - Egypt wereincluded. Patients with chronic renal disease,thyroid disease, malignancy, patients receivingcorticosteroid therapy, with serum creatinine > 1.4 mg/dland patients receiving diuretics or large volumes of IVfluids were excluded. Serum creatinine, serum cystatinC, adjusted creatinine clearance (Adj Ccr), estimatedGFR (eGFR) by modification of diet in renal disease(MDRD), abbreviated MDRD (abb MDRD) andCockcroft-Gault (CG) formulae were measured. Patientswith renal dysfunction (adj Ccr < 80 ml/min/1.73m2)were 26 (52%) in number. Patients with renaldysfunction and high serum creatinine were 12/26(46.2%) while those with high cystatin C were 23/26(88.5%). Cystatin C was found to be significantlycorrelated with serum creatinine, adj Ccr and eGFR by all studied formulae. Using receiver operatingcharacteristic (ROC) analysis; AUC for Cystatin C(0.976) was more than that for eGFR by abb MDRD(AUC=0.839), MDRD (AUC=0.822), CG formulae(AUC=0.808) and serum creatinine (AUC=0.710)respectively. In conclusion; cystatin C was found to bebetter than serum creatinine, eGFR by abb MDRD,MDRD and CG formulae in detection of early renaldysfunction at a single point in critically ill patients

Modeling thermoelastoplasticity of composite materials

The prediction of the thermoelastoplastic behaviors of composite materials and the corresponding constituents is essential and needs to be investigated from the theoretical and experimental aspects. One of the promising theories to predict the behaviors of a composite on the micro-scale using finite element analysis is the multi-continuum theory (MCT). It is also used for evaluating the constituent-averaged elastic stress and strain from the composite-averaged counterparts. In this research, the MCT is extended to handle the thermoelastoplastic behaviors of composites. A micromechanical model, which combines Eshelby and Mori-Tanaka models, is used to determine the effective composite properties using the constituents ones. These properties are used to propose incremental non-linear governing equations. Also, the thermoelastoplastic decomposition of the composite strain is carried out to determine the constituents stresses and strains. The current work is validated by comparing its results with some others in the literature and good agreement is obtained