Numerical Investigation of Flow and Heat Transfer in Vane Impingement/Effusion Cooling with Various Rib/Dimple Structure

By investigating heat transfer and flow structures of dimples,orthogonal ribs,and V-shaped ribs in the impingement/effusion cooling,the article is dedicated to selecting a best-performing internal cooling structure for a turbine vane.The overall cooling effectiveness and coolant consumption are adopted to evaluate the cooling performance.To analyze the influence of structural modification,the flow field is investigated on chordwise/spanwise sections and the target surface.The blockage effect on crossflow can protect jet flow,resulting in higher heat transfer performance of the target surface.Ribs own a stronger blockage effect than dimples.Compared with the blockage effect,the influence of the rib shape is negligible.By installing dimples between ribs,heat transfer is augmented further.The introduction of ribs/dimples leads to higher discharge coefficients of jet nozzles but lower discharge coefficients of film holes.Thus,the film cooling deteriorates.Meanwhile,the installation of the ribs and dimples decreases total coolant consumption.The effect of ribs/dimples on heat transfer and effusion condition of internal and external cooling is analyzed.The best-performing cooling structure is the target surface with dimples and orthogonal ribs,which decreases the wall temperature and coolant consumption by 14.57-28.03 K and 1.19%-1.81%respectively.This article concludes the flow mechanism for dimples and influence factors on the cooling performance,which may serve as guidance for the turbine vane design.

Numerical Study of Flow and Heat Transfer Characteristics of Impingement/Effusion Cooling

Three-dimensional numerical simulation is carried out to investigate the flow and heat transfer characteristics of impingement/effusion cooling systems. The impingement/effusion holes are arranged on two parallel perforated plates respectively in a staggered manner. Every effusion hole has an inclined angle of 30° with respect to the surface. The two parallel plates are spaced three times the diameter of the effusion hole. The ratio of center-to-center spacing of adjacent holes to the diameter of the effusion hole is set to be 3.0, 4.0 and 5.0 respectively. The flow field, temperature field and wall film cooling effectiveness are calculated for different blowing ratios ranging from 0.5 to 1.5. In general, the wall cooling effectiveness increases as the center-to-center spacing of adjacent holes decreases or the blowing ratio increases.

Subxyphoid Pericardial Drainage for Tuberculous Pericardial Effusion in Antananarivo

Introduction: Tuberculosis is the leading cause of pericardial effusion in sub-Saharan African countries. The aim of this study was to describe the diagnosis and the surgical management of tuberculous pericardial effusion in low-income country. Methods: This was a retrospective and descriptive study performed at Vascular Surgery Unit for 10 years-period (from January 2012 to December 2021), including all cases of drainage of pericardial effusion due to tuberculosis. Results: Sixty-seven cases were recorded, including 38 males (56.71%) and 29 women (43.28%). The average age was 35.47 years old. Patients lived in urban areas in 67.16% of cases. Thirteen patients (13.43%) had a previous history of pulmonary tuberculosis. The most common risk factors for tuberculosis infection were malnourishment (80.59%), indoor air pollution (77.61%) and close contact with tuberculosis patient (40.29%). The commonest symptom were dyspnea, (95.52%), chest pain (89.55%), fever (67.16%), tachycardia (95.52%) and cough (80.59%). Twenty-seven patients (39.02%) presented clinical signs of cardiac tamponade. Electrocardiogram showed sinus tachycardia (97.53%) with microvoltage (39.02%). Chest-X-ray showed cardiomegaly (100%) and pleural effusion (56.71%). Echocardiography showed moderate (43.28%) and large (56.71%) pericardial effusion. All patients underwent subxiphoid pericardial drainage. Mycobacterium tuberculosis detection via GeneXpert test of pericardial effusion were positive in 38.80% of patients. Pericardial biopsies confirmed the diagnosis of tuberculosis in 41.79%. The mortality rate was 8.95%. Conclusion: Subxiphoid pericardial drainage reduced thr risk of cardiac tamponade in patients with massive pericardial effusion. Histopathology of pericardial biopsies made a definitive diagnosis for tuberculosis.

Bacteriological Profile of Effusion Fluids Infections at Charles De Gaulle University Pediatric Hospital from 2017 to 2020

Introduction: Microbiology of effusion fluids in children in Burkina Faso is characterized by the scarcity of data. This work aimed to study the bacteriological and antibiotics susceptibility profile of bacteria involved in effusion fluid infections in paediatrics in order to improve the choice of probabilistic antibiotics therapy. Methods: A cross-sectional, descriptive study was used in children aged 0 to 15 years from 2017 to 2020 at the Charles De Gaulle Pediatric University Hospital Center (CHUP-CDG) in Ouagadougou. Classical bacteriology methods such as macroscopy, Gram staining, identification galleries and antibiotics susceptibility testing were used. Results: Of 231 samples, 64 bacteria were isolated. The most common bacterial strains of pleural fluid were Staphylococcus aureus (25%) and 40% for Enterobacteriaceae. Of the peritoneal fluid, 77% were Enterobacteriaceae with 57% Escherichia coli;and from joint fluid, 33% were S. aureus and 22% for P. aeruginosa. The overall susceptibility profile showed 29% extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL), 10% methicillin-resistant S. aureus (MRSA), and 8% carbapenemases. Conclusion: Bacteriological profile is characterized by ESBL-producing Enterobacteriaceae and MRSA. The most active antibiotics were macrolides, aminoglycosides, and cefoxitin (methicillin) for Gram-positive cocci, carbapenems, and aminoglycosides for Gram-negative bacilli. Then, the monitoring of antibiotics resistance must be permanent.

Comparison of efficacy of lung ultrasound and chest X-ray in diagnosing pulmonary edema and pleural effusion in ICU patients: A single centre, prospective, observational study

Background and Aims While chest X-ray (CXR) has been a conventional tool in intensive care units (ICUs) to identify lung pathologies, computed tomography (CT) scan remains the gold standard. Use of lung ultrasound (LUS) in resource-rich ICUs is still under investigation. The present study compares the utility of LUS to that of CXR in identifying pulmonary edema and pleural effusion in ICU patients. In addition, consolidation and pneumothorax were analyzed as secondary outcome measures. Material and Methods This is a prospective, single centric, observational study. Patients admitted in ICU were examined for lung pathologies, using LUS by a trained intensivist;and CXR done within 4 hours of each other. The final diagnosis was ascertained by an independent senior radiologist, based on the complete medical chart including clinical findings and the results of thoracic CT, if available. The results were compared and analyzed. Results Sensitivity, specificity and diagnostic accuracy of LUS was 95%, 94.4%, 94.67% for pleural effusion;and 98.33%, 97.78%, 98.00% for pulmonary edema respectively. Corresponding values with CXR were 48.33%, 76.67%, 65.33% for pleural effusion;and 36.67%, 82.22% and 64.00% for pulmonary edema respectively. Sensitivity, specificity and diagnostic accuracy of LUS was 91.30%, 96.85%, 96.00% for consolidation;and 100.00%, 79.02%, 80.00% for pneumothorax respectively. Corresponding values with CXR were 60.87%, 81.10%, 78.00% for consolidation;and 71.3%, 97.20%, 96.00% for pneumothorax respectively. Conclusion LUS has better diagnostic accuracy in diagnosis of pleural effusion and pulmonary edema when compared with CXR and is thus recommended as an effective alternative for diagnosis of these conditions in acute care settings. Our study recommends that a thoracic CT scan can be avoided in most of such cases.

Pulmonary Edema and Pleural Effusion Detection Using Efficient Net-V1-B4 Architecture and AdamW Optimizer from Chest X-Rays Images

This paper presents a novelmulticlass systemdesigned to detect pleural effusion and pulmonary edema on chest Xray images,addressing the critical need for early detection in healthcare.A new comprehensive dataset was formed by combining 28,309 samples from the ChestX-ray14,PadChest,and CheXpert databases,with 10,287,6022,and 12,000 samples representing Pleural Effusion,Pulmonary Edema,and Normal cases,respectively.Consequently,the preprocessing step involves applying the Contrast Limited Adaptive Histogram Equalization(CLAHE)method to boost the local contrast of the X-ray samples,then resizing the images to 380×380 dimensions,followed by using the data augmentation technique.The classification task employs a deep learning model based on the EfficientNet-V1-B4 architecture and is trained using the AdamW optimizer.The proposed multiclass system achieved an accuracy(ACC)of 98.3%,recall of 98.3%,precision of 98.7%,and F1-score of 98.7%.Moreover,the robustness of the model was revealed by the Receiver Operating Characteristic(ROC)analysis,which demonstrated an Area Under the Curve(AUC)of 1.00 for edema and normal cases and 0.99 for effusion.The experimental results demonstrate the superiority of the proposedmulti-class system,which has the potential to assist clinicians in timely and accurate diagnosis,leading to improved patient outcomes.Notably,ablation-CAM visualization at the last convolutional layer portrayed further enhanced diagnostic capabilities with heat maps on X-ray images,which will aid clinicians in interpreting and localizing abnormalities more effectively.

Pleural effusion,ascites,colon ulcers and hematochezia:What we can learn from the diagnostic process of a patient with plasma cell myeloma:A case report

BACKGROUND Plasma cell myeloma(PCM)is characterized by hypercalcemia,renal impairment,anemia,and bone destruction.While pleural effusion,ascites,abdominal pain,and bloody stool are common manifestations of lung disease or gastrointestinal disorders,they are rarely observed in patients with PCM.CASE SUMMARY A 66-year-old woman presented with complaints of recurrent chest tightness,wheezing,and abdominal bloating accompanied by bloody stools.Computed tomography revealed pleural effusion and ascites.Pleural effusion tests showed inflammation,but the T-cell spot test and carcinoembryonic antigen were negative.Endoscopy showed colonic mucosal edema with ulcer formation and local intestinal lumen stenosis.Echocardiography revealed enlarged atria and reduced left ventricular systolic function.The diagnosis remained unclear.Further testing revealed elevated blood light chain lambda and urine immunoglobulin levels.Blood immunofixation electrophoresis was positive for immunoglobulin G lambda type.Smear cytology of the bone marrow showed a high proportion of plasma cells,accounting for about 4.5%.Histopathological examination of the bone marrow suggested PCM.Flow cytometry showed abnormal plasma cells with strong expression of CD38,CD138,cLambda,CD28,CD200,and CD117.Fluorescence in situ hybridization gene testing of the bone marrow suggested 1q21 gene amplification,but cytogenetic testing showed no clonal abnormalities.Colonic mucosa and bone marrow biopsy tissues were negative for Highman Congo red staining.The patient was finally diagnosed with PCM.CONCLUSION A diagnosis of PCM should be considered in older patients with pleural effusion,ascites,and multi-organ injury.

Subdural effusion associated with COVID-19 encephalopathy: A case report

BACKGROUND The precise mechanism by which severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)impacts the central nervous system remains unclear,with manifestations spanning from mild symptoms(e.g.,olfactory and gustatory deficits,hallucinations,and headache)to severe complications(e.g.,stroke,seizures,encephalitis,and neurally demyelinating lesions).The occurrence of single-pass subdural effusion,as described below,is extremely rare.CASE SUMMARY A 56-year-old male patient presented with left-sided limb weakness and slurred speech as predominant clinical symptoms.Through comprehensive imaging and diagnostic assessments,he was diagnosed with cerebral infarction complicated by hemorrhagic transformation affecting the right frontal,temporal,and parietal regions.In addition,an intracranial infection with SARS-CoV-2 was identified during the rehabilitation process;consequently,an idiopathic subdural effusion developed.Remarkably,the subdural effusion underwent absorption within 6 d,with no recurrence observed during the 3-month follow-up.CONCLUSION Subdural effusion is a potentially rare intracranial complication associated with SARS-CoV-2 infection.

Pleural effusion in critically ill patients and intensive care setting

Pleural effusion usually causes a diagnostic dilemma with a long list of differential diagnoses.Many studies found a high prevalence of pleural effusions in critically ill and mechanically ventilated patients,with a wide range of variable prevalence rates of up to 50%-60%in some studies.This review emphasizes the importance of pleural effusion diagnosis and management in patients admitted to the intensive care unit(ICU).The original disease that caused pleural effusion can be the exact cause of ICU admission.There is an impairment in the pleural fluid turnover and cycling in critically ill and mechanically ventilated patients.There are also many difficulties in diagnosing pleural effusion in the ICU,including clinical,radiological,and even laboratory difficulties.These difficulties are due to unusual presentation,inability to undergo some diagnostic procedures,and heterogenous results of some of the performed tests.Pleural effusion can affect the patient’s outcome and prognosis due to the hemodynamics and lung mechanics changes in these patients,who usually have frequent comorbidities.Similarly,pleural effusion drainage can modify the ICUadmitted patient’s outcome.Finally,pleural effusion analysis can change the original diagnosis in some cases and redirect the management toward a different way.

Combined aqueous misdirection and persistent choroidal effusions following implantation of a Preserflo Micro Shunt

AIM:To describe a case of aqueous misdirection complicated by subsequent persistent choroidal effusions following implantation of a Preserflo Micro Shunt(PMS)device to treat advanced closed angle glaucoma.METHODS:A 67-year-old caucasian female with advanced primar y angle-closure glaucoma on four medications with an intraocular pressure(IOP)of 26 mm Hg was listed for a PMS insertion with mitomycin C(MMC).RESULTS:Past ocular history was significant for pseudophakia and previous yttrium aluminum garnet(YAG)peripheral iridotomy.Surgery was uneventful but on the first postoperative day,she developed aqueous misdirection complicated by subsequent development of persistent uveal effusions.Conventional treatment strategies including atropine drops,YAG hyaloidotomy and choroidal effusion drainage proved ineffective.A combination of oral steroids and pars plana vitrectomy(PPV)along with an irido-zonulohyloidectomy(IZH)proved efficacious.CONCLUSION:To the best of the author’s knowledge,this is the first published case of aqueous misdirection complicated with the presence of significant,unresolving choroidal effusions,highlighting the possibility and sequelae of comorbid pathology in nanophthalmic eyes.

Pleuro-Pericardial Inflammation and Effusion: A Rare Acute Initial Presentation of Rheumatoid Arthritis

Background: Rheumatoid arthritis is a systemic inflammatory arthritis characterized by joint pain and morning stiffness. The affected joints are typically symmetrically affected, and given the inflammatory nature of this condition, patients often present with warmth and erythema around affected joints as well as fatigue. Extra-articular manifestations, especially pleuro-pericardial inflammation, are rare initial presentations, although may be seen in advanced or undertreated disease. Case Presentation: We describe a case of a rheumatoid arthritis presenting atypically in a middle-aged male who came to the emergency department complaining of diffuse muscle pain and swelling in the distal extremities. Cardiac ultrasound revealed pleuro-pericardial inflammation and effusions. Myositis and infectious causes were ruled out and bilateral hand x-rays did not show erosions or any evidence of arthritic changes. All rheumatological auto-antibodies were negative except for rheumatoid factor and anti-cyclic citrullinated peptide (CCP) and a diagnosis of rheumatoid arthritis was made. The patient was started on prednisone with excellent response. Conclusions: This case highlights that rheumatoid arthritis can uncommonly present initially with extra-articular manifestations that are often manifested in advanced disease. Typically, extra-articular manifestations, especially those as severe as this patient’s, occur with untreated, advanced disease and could accompany extensive arthritic joint changes. Thus, it is important to have an understanding of rare, atypical presentations of rheumatoid arthritis so that a high index of suspicion can be maintained to make the diagnosis and initiate treatment in a timely manner.

Development of subdural empyema from subdural effusion after suppurative encephalitis:A case report

BACKGROUND Chronic subdural effusion is very common in the cranial imaging of middle-aged and older people.Herein,we report a patient misdiagnosed with subdural effusion,who was eventually diagnosed with chronic subdural empyema(SDE)caused by Streptococcus pneumoniae.CASE SUMMARY A 63-year-old man was brought to our emergency room with a headache,vomiting,and disturbed consciousness.Computed tomography(CT)revealed a bilateral subdural effusion at the top left side of the frontal lobe.Cerebrospinal fluid examination after lumbar puncture indicated suppurative meningitis,which improved after anti-infective therapy.However,the patient then presented with acute cognitive dysfunction and right limb paralysis.Repeat CT showed an increase in left frontoparietal subdural effusion,disappearance of the left lateral ventricle,and a shift of the midline to the right.Urgent burr hole drainage showed SDE that was culture-positive for Streptococcus pneumoniae.His condition improved after adequate drainage and antibiotic treatment.CONCLUSION Patients with unexplained subdural effusion,especially asymmetric subdural effusion with intracranial infection,should be assessed for chronic SDE.Early surgical treatment may be beneficial.

Metagenomic next-generation sequencing for pleural effusions induced by viral pleurisy:A case report

BACKGROUND Viral pleurisy is a viral infected disease with exudative pleural effusions.It is one of the causes for pleural effusions.Because of the difficult etiology diagnosis,clinically pleural effusions tend to be misdiagnosed as tuberculous pleurisy or idiopathic pleural effusion.Here,we report a case of pleural effusion secondary to viral pleurisy which is driven by infection with epstein-barr virus.Viral infection was identified by metagenomic next-generation sequencing(mNGS).CASE SUMMARY A 40-year-old male with a history of dermatomyositis,rheumatoid arthritis,and secondary interstitial pneumonia was administered with long-term oral prednisone.He presented with fever and chest pain after exposure to cold,accompanied by generalized sore and weakness,night sweat,occasional cough,and few sputums.The computed tomography scan showed bilateral pleural effusions and atelectasis of the partial right lower lobe was revealed.The pleural fluids were found to be yellow and slightly turbid after pleural catheterization.Thoracoscopy showed fibrous adhesion and auto-pleurodesis.Combining the results in pleural fluid analysis and mNGS,the patient was diagnosed as viral pleuritis.After receiving Aciclovir,the symptoms and signs of the patient were relieved.CONCLUSION Viral infection should be considered in cases of idiopathic pleural effusion unexplained by routine examination.mNGS is helpful for diagnosis.

Ultrasound Value in the Management of Parapneumonic Pleural Effusions in a Limited-Resource Setting: A Case Report

Pleural effusion is a common complication of acute lung infection, with rising morbidity and mortality. If poorly treated, parapneumonic effusion evolves to the fibrino-purulent stage wherein antibiotic therapy alone becomes inadequate. Chest CT is the gold standard diagnostic imaging tool, however, in a resource-limited context, it may not be performed. Chest ultrasound can therefore be an alternative for drainage and intermittent follow-up of complicated parapneumonic pleural effusions. We report the case of a 4-year-old child who presented with cough, breathing difficulties and fever for over two weeks and in whom an initial chest X-ray revealed a left hemithorax white-out with an air-fluid level. Chest ultrasound revealed a left pleuropulmonary massive fluid collection with an encysted empyema. It also allowed ultrasound-guided pleural effusion drainage of a fibrino-purulent liquid which tested positive for Kocuria kristinae, a bacterium sensitive to gentamycin, vancomycin, norfloxacin and clindamycin. The next follow-up ultrasound checks showed improvement and the control chest X-ray performed one month later demonstrated pulmonary functional recovery. This case highlights the importance of ultrasound in the management and follow-up of this chest pathology in resource-limited settings.

Primary Effusion Lymphoma in a HIV-1/2-Infected Patient

Background: Primary effusion lymphoma (PEL) is a lymphoid proliferation related to Kaposi sarcoma herpesvirus 8/human herpesvirus 8 (KSHV/HHV8) that affects mainly human immunodeficiency virus (HIV) infected individuals but can also occur in other immunodeficiency settings. It is characterized by lymphomatous effusions in different serous body cavities without the presence of a detectable tumor mass. The diagnosis is challenging and the clinical outcomes are poor. Aim: The aim of this paper is to report a rare case of PEL in a man who have sex with women (MSW) with HIV-1/2 infection, history of visceral Kaposi sarcoma (KS) and the development of a seronegative arthritis previous to the lymphoproliferative disease diagnosis. PEL presented with ascites, was treated with high-dose chemotherapy and autologous stem cell transplantation, with a good clinical outcome. Case Presentation: We describe a case of a 48-year-old HIV-1/2-infected patient from a high HHV8 seroprevalent country, hospitalized following a three-month history of increased abdominal volume and general constitutional symptoms. Laboratory data revealed normocytic normochromic anemia and a high level of lactate dehydrogenase. A diagnostic paracentesis was performed with cytology compatible with high-grade B-cell lymphoma. Peritoneal fluid cytology showed large lymphoid cells expressing leucocyte-common antigen CD45 without expression of the CD20 antigen (B-lymphocytes) and positivity for HHV8 by immunocytochemical staining, compatible with the diagnosis of PEL.

A Pleural Effusion Secondary to Unusual Dual Pathology: A Case Report

Pleural effusion is a commonly encountered respiratory disorder. In the majority of cases, a single causative agent is responsible. Pleural effusions resulting from simultaneous involvement of the membranes by two different pathologic processes are unusual.

CONVEXITY OF THE FREE BOUNDARY FOR AN AXISYMMETRIC INCOMPRESSIBLE IMPINGING JET

This paper is devoted to the study of the shape of the free boundary for a threedimensional axisymmetric incompressible impinging jet.To be more precise,we will show that the free boundary is convex to the fluid,provided that the uneven ground is concave to the fluid.

Numerical Analysis of the Influence of the Impinging Distance on the Scouring Efficiency of Submerged Jets

Water jet technology is widely used in submerged buried pipes as a non-traditional trenching process,often invol-ving a complex sediment response.An important adjustable and influential engineering variable in this technol-ogy is represented by the impinging distance.In this study,the FLOW-3D software was used to simulate the jet scouring of sand beds in a submerged environment.In particular,four sets of experimental conditions were con-sidered to discern the relationship between the maximum scour depth and mass and the impinging distance.As shown by the results,a critical impinging distance h0 exists by which the static scour depth can be maximized;the scour mass ratio between dynamic and static conditions decreases as the impinging distance increases.Moreover,the profile contours are similar when the erosion parameter Ec is in the range 0.35<Ec<2.Empirical equations applicable for predicting the jet trenching contour under both dynamic and static scour modes are also provided in this study.

Numerical study of flow and thermal characteristics of pulsed impinging jet on a dimpled surface

This research comprehensively investigates the flow and thermal characteristics of a pulsating impinging jet over a dimpled surface.It analyzes the impact of key parameters(e.g.,inlet velocity pulsation functions,pulsation frequency,amplitude,dimple pitch,dimple depth,Reynolds number)on flow patterns and heat transfer.Validated computational fluid dynamics and the Re-normalization group turbulence model are employed to accurately simulate complex turbulent flow behavior.Local and average heat transfer coefficients are calculated and compared to steady impingement cases,revealing the potential benefits of pulsation for heat transfer enhancement.The study also examines how pulsation-induced flow modulation and thermal mixing affect heat transfer mechanisms.Results indicate that combining fluctuating flow with a dimpled surface can improve heat transfer rates.In summary,increasing pulsation amplitude consistently enhances heat transfer,while the effect of frequency varies between impinging and wall jet zones.

Otitis media with effusion in children: Pathophysiology, diagnosis, and treatment.A review

Otitis media with effusion(OME)is a frequent paediatric disorder.The condition is often asymptomatic,and so can easily be missed.However,OME can lead to hearing loss that impairs the child's language and behavioural development.The diagnosis is essentially clinical,and is based on otoscopy and(in some cases)tympanometry.Nasal endoscopy is only indicated in cases of unilateral OME or when obstructive adenoid hypertrophy is suspected.Otitis media with effusion is defined as the observation of middle-ear effusion at consultations three months apart.Hearing must be evaluated(using an age-appropriate audiometry technique)before and after treatment,so as not to miss another underlying cause of deafness(e.g.perception deafness).Craniofacial dysmorphism,respiratory allergy and gastro-oesophageal reflux all favour the development of OME.Although a certain number of medications(antibiotics,corticoids,antihistamines,mucokinetic agents,and nasal decongestants)can be used to treat OME,they are not reliably effective and rarely provide long-term relief.The benchmark treatment for OME is placement of tympanostomy tubes(TTs)and(in some cases)adjunct adenoidectomy.The TTs rapidly normalize hearing and effectively prevent the development of cholesteatoma in the middle ear.In contrast,TTs do not prevent progression towards tympanic atrophy or a retraction pocket.Adenoidectomy enhances the effectiveness of TTs.In children with adenoid hypertrophy,adenoidectomy is indicated before the age of 4 but can be performed later when OME is identified by nasal endoscopy.Children must be followed up until OME has disappeared completely,so that any complications are not missed.