Rozprawy doktorskie na temat „Effusion”
Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Effusion.
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Effusion”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Collins, Matthew C. J. "Casing effusion cooling". Thesis, University of Oxford, 2014. https://ora.ox.ac.uk/objects/uuid:8a7204f5-9436-4c11-b6d6-25aef0bff8f7.
Pełny tekst źródłaStreszczenie:
The design, modelling and testing of a film cooling system intended for the casing of an unshrouded HP turbine rotor is described in this thesis. Due to the dense network of small film cooling holes employed in such a system, this is often referred to as a casing effusion cooling scheme. Though there are patent references to such systems, there is as yet very limited published material on the aero thermal performance of such film cooling schemes. The casing of an unshrouded HP rotor is an incredibly hostile environment, witnessing the periodic passing of the HP rotor tips within close proximity at a frequency of ∼10 kHz. These blade passing events subject the casing to extremely large amplitude fluctuations of pressure and heat load, which may at first seem to preclude the use of a film cooling scheme. This thesis details many theoretical, computational and experimental advancements related to the research topic. Highlights include: The introduction of a new fundamental mechanism to the field of film cooling, the propagation and reflection of pressure waves within film cooling holes and the impact on film cooling performance. The development of new miniature thin film heat flux gauges manufactured using a new process. Sensor resolution is improved by a factor of seven. The first published computational model reporting heat transfer data on a film cooled rotor casing. Improvements to heat transfer data processing techniques and theory. These are applied to experimental work to produce the highest resolution heat transfer data obtained on the casing of a scaled rotating transonic HP rotor for both uncooled and cooled geometries. Computational models are used to demonstrate that coolant injection on the rotor casing reduces the over-tip leakage mass flow, offsetting the spoiling and mixing losses that film cooling schemes introduce. Much of the work in this thesis is based on papers that have been submitted to or are pending submission. To date three papers have been presented at conference with two published in journals and the third recommended and pending journal publication. Two other papers are pending submission. A patent has also been filed with the European and American patent office regarding novel film cooling hole shapes designed to make use of acoustic effects.
2
CUNHA, M. N. PINTO DA. "IMMUNOPROFILE IN EFFUSION CYTOLOGY". Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150058.
Pełny tekst źródłaStreszczenie:
BACKGROUND: Cytology has a crucial role for diagnosing pleural and abdominal effusions. A prompt accurate diagnosis has both prognostic and therapeutic significance. However, cell morphology alone is not always sufficient to formulate such a diagnosis. In human medicine, immunocytochemistry of effusion cytology has now standardized procedures that provide reliable insights into various diagnostic dilemmas. OBJECTIVE: To describe the method of immunocytochemistry in effusion cytology and to estimate the value of a panel of
markers in identifying cells in canine and feline effusions. MATERIALS AND METHODS: Human, feline and canine mesothelial cells were isolated in culture. Western‐blot (WB) analysis was used to ascertain antibody cross‐reactivity for all the markers, with the exception of HBME‐1. Forty‐four cytospined or smeared effusion specimens from dogs and cats with a cytological diagnosis of reactive
effusion or malignancy of non‐hematopoietic origin were stained with a standard
panel of Vimentin, Cytokeratin (CK) AE1/AE3, CK 5/6 and HBME‐1 as mesothelial cell markers; desmin as mesothelial cell malignancy marker; and CK7/CK20 as a marker of metastasis. Malignancy was confirmed by histologic evaluation; non‐malignant conditions were confirmed by follow‐up. Sensitivities, specificities and predictive values were calculated. RESULTS: The WB analysis confirmed the specific crossreactivity of the human antibodies for canine and feline proteins in mesothelial tissue. No significant differences were found
between canine and feline results. Vimentin/cytokeratin coexpression had a
sensitivity of 79% and a specificity of 92%, HBME‐1 had 89% sensitivity and 23% specificity, and CK5/6 had 26% sensitivity and 100% specificity for mesothelial cells. Desmin had only 20% specificity for benign mesothelial cells, while CK7‐/CK20+ had a specificity of 79% and sensitivity of 30% for metastatic cells on effusions. CONCLUSION: Immunocytochemistry can be applied in effusion samples, and valuable results can be obtained. The most useful marker, with the highest overall accuracy for the identification of mesothelial cells in effusion, is the Vim/CK coexpression, being CK5/6 the more specific and HBME‐1
the more sensitive antibody. Desmin is not useful for discriminating between benign and malignant mesothelial cells. The coordinate expression of CK7‐/CK20+ has not proved to be useful on the identification of metastatic cells on effusions.
3
Fitzgerald, J. E. "Characterization of mucus glycoproteins in middle ear effusions from children with otitis media with effusion". Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383976.
Pełny tekst źródła
4
Clive, Amelia Olga. "Management of malignant pleural effusion". Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683557.
Pełny tekst źródłaStreszczenie:
Introduction Malignant pleural disease is a growing clinical problem and often results in substantial breathlessness for patients due to the accumulation of malignant pleural effusion. Dedicated pleural services are becoming more prevalent and a wider selection of treatment strategies are now available. This thesis evaluates a number of different aspects relating to the prognostication and treatment of patients with malignant pleural disease through a series of 4 studies. Methods The first study uses data from three, international, prospectively collected databases of patients with malignant pleural effusion to evaluate factors that predict patients' survival. From this data, the LENT prognostic score is developed and validated to assist clinicians in risk stratifying patients and thereby helping them to select appropriate treatment strategies. The second study is a systematic review of the literature, evaluating all the published randomised controlled trial (RCT) data on the management of malignant pleural effusion using network meta-analysis. These results highlight the efficacy of talc poudrage in obtaining a pleurodesis, but also emphasise the heterogeneity of the available evidence and the paucity of robust data on symptom based outcomes and adverse effects. The Zoledronic Acid (ZA) Trial is a pilot, RCT evaluating whether intravenous ZA is an effective potential treatment for MPE. In this small, diverse cohort, no significant difference was seen in the radiology, biomarkers or symptoms of the ZA group compared with those who received placebo. Finally, the SMART trial is a multi-centre RCT, evaluating the role of prophylactic radiotherapy in mesothelioma. 203 patients have been recruited to the study, which is currently in follow up and the results are awaited in winter 2015. Discussion This thesis adds to our understanding regarding the prognostication and management of patients with malignant pleural disease. The data will help to inform clinicians and future research studies regarding the optimal management of these patients
5
Tasker, Andrea. "Otitis media with effusion : key factors". Thesis, University of Newcastle Upon Tyne, 2003. http://hdl.handle.net/10443/1075.
Pełny tekst źródłaStreszczenie:
Otitis media with effusion (OME) is a disease characterised by inflammation of the middle ear and changes in middle ear mucosa from a columnar to a more secretory type epithelium, with a proliferation of goblet cells and mucus glands. There is excessive production of mucus, resulting in the accumulation of a viscous effusion in the middle ear cleft. Various factors have been implicated in the aetiology of the disease including bacteria, Eustachian tube dysfunction, allergy and craniofacial abnormalities. It has been suggested that laryngopharyngeal reflux could be an inflammatory co-factor and possible cause of many upper respiratory disorders including OME. The aims of this thesis were to examine effusions for the presence of gastric juice and were also concerned with the biochemical and rheological characterisation of effusions. Acidic proteinase (pepsin) activity measured at pH2.2 using the N-terminal assay was detected in 29% of effusions and 91% of these samples contained pepsin/pepsinogen protein at elevated levels compared to serum (using an ELISA). As other serum protein levels in effusions were of the same order as serum reference levels, the source of the activity was unlikely to be from a transudate of plasma and rather due to the reflux of gastric contents into the middle ear. The data suggests that reflux may be a primary factor in the initiation of OME in children. Middle ear effusions are mucin-rich secretions that demonstrate a lack of degradation on storage. They contained at least two distinct mucin populations, MUC5B is the major mucin and MUC5AC is present at much lower levels. MUC5B had a significant correlation with effusion specific viscosity suggesting that it is responsible for the rheological properties of the effusion. Interleukin-8 (IL-8) levels in effusions had significant correlation with MUC5AC and it may be that MUC5AC is produced in response to IL-8 in the middle ear during the inflammatory process of glue ear. Neither IL-6 nor IL-8 levels correlated with MUC5B content. It is likely that a different stimulus or other cytokine is responsible for the regulation of MUCSB. There was a significant correlation between IL-6 and IL-8 levels in effusions demonstrating that one cytokine could stimulate the secretion of the other. Further studies developing from the work presented in this thesis would involve analysis of effusions for other components of gastric juice, such as gastric lipase and intrinsic factor, to confirm the role of reflux in OME. A study following children from the diagnosis stage through the disease course and grommet insertion for glue ear with awareness of signs and symptoms of reflux would assess the proportion of children with glue ear associated with reflux. An animal model for reflux could be set up, instilling gastric juice components into the middle ear via the nasopharynx/ET to see if an effusion develops. Effusions could be analysed for other cytokines (such as IL-10 or TNF-a) to see if levels correlate with MUC5B content.
6
Hasebe, Seishi. "Organic change of effusion in the mastoid in otitis media with effusion and its relation to attic retraction". Kyoto University, 2001. http://hdl.handle.net/2433/150174.
Pełny tekst źródła
7
Andoh, Honoré Yobouet. "Refroidissement de paroi par effusion : Etude expérimentale". Lyon, INSA, 1992. http://www.theses.fr/1992ISAL0088.
Pełny tekst źródłaStreszczenie:
L'un des procédés de refroidissement des parois de chambres de combustion, lorsque celles-ci sont poreuses, consiste à les refroidir par effusion d'un gaz froid s'é1 coulant de l'extérieur vers l' intérieur. Le travail consiste à analyser l'efficacité d'un tel système. Un modèle d'écoulement à travers la paroi, basé sur une loi de type "Blasius" et résolu selon la méthode des différences finies, a été élaboré Comparé à divers modèles de la littérature, i1 a été validé par des expériences diversifiées quant à la nature du fluide et aux conditions de température et de pression. Le modèle de transferts thermiques à 1'intérieur de la paroi utilise l'équation de l'énergie et une méthode de résolution aux différences finies. Il permet d'étudier la sensibilité du phénomène aux divers paramètres. L'un d'eux, le coefficient d'échange convectif interne est prépondérant. Sa valeur est obtenue par des corrélations semi-ernpiriques issues de la bibliographie ou par une méthode expérimentale indirecte délicate à mener du fait des puissances thermiques importantes à mettre en jeu. Une modélisation simple de la couche limite, utilisant l'hypothèse d'une couche laminaire en déplacement perpendiculairement à la paroi, permet de calculer le flux thermique reçu à la paroi. Une épaisseur de couche limite de quelques centièmes de millimètres suffit à limiter considérablement le flux. Un programme de calcul global est exploité pour analyser l'efficacité du mode de refroidissement étudié lorsqu'on fait varier les paramètres essentiels ; pression amont et aval de la paroi, température des fluides chauds et froids, nature du matériaux, nature du fluide, coefficient de convection interne et épaisseur de la couche limiteOne solution for the cooling of combustion chamber walls, when they are porous, consists of cooling them by effusion of a cold gas flowing from outside to inside this work aims to analyse the performance of such a system. A model of flowing throw the wall, based on a Blasius type law and solved by a finite difference method, was developed. Compared to various model found in the literature, it was applied to experiments with various fluids, operating temperatures and pressures. The model of beat transfer inside the wall uses the energy equation and a finite difference method solving. It is allows to study the sensitivity of mechanism to various parameters. One at them - the internal convective heat transfer coefficient is preponderant. Its value is obtained by semi-empirical equation given by the literature or by an indirect experimental method, difficult to carry out due to the great thermal involved. A simple modelling of the boundary layer, using the assumption of a laminar layer moving perpendicular to the wall, allows to calculate the heat flux get by the wall. A boundary layer of a few hundredth millimetres thickness is enough to considerably limit the flux. A global simulation program is used to analyse the performance of the studied cooling mode. When the main parameters vary, pressures, up-stream and down-stream to the wall, cold and hot gases temperatures, material, fluid, internal convection coefficient, boundary layer thickness
8
Garske, Luke Albert. "Determinants of dyspnea associated with pleural effusion". Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/122900/1/Luke_Garske_Thesis.pdf.
Pełny tekst źródłaStreszczenie:
Fluid accumulation between the lung and rib-cage is commonly associated with shortness of breath, and frequently requires hospitalisation and invasive surgical procedures. This program of research has contributed new knowledge which has advanced our understanding of how fluid accumulation between the lung and rib cage causes shortness of breath. A technique was refined to measure the efficiency of the breathing muscles when fluid accumulates between the lung and rib cage. A novel non-invasive therapy to improve efficiency of the breathing muscles was trialled in a patient, and may improve shortness of breath.
9
Crippa, V. "CELL BLOCKS OF CANINE AND FELINE EFFUSION". Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/350850.
Pełny tekst źródłaStreszczenie:
ABSTRACT
Valentina Crippa
Cell Blocks from canine and feline effusions
Objective: To evaluate the sensitivity and specificity of a panel of markers in distinguishing mesothelial cells from metastatic adenocarcinoma cells in Cell blocks from canine and feline effusion.
Methods: This study included 28 effusion specimens from dogs and cats with a cytological diagnosis of reactive effusion or malignancy of non-hematopoietic origin. Cell Blocks were stained with a standard panel of Vimentin, panCK (MNF116), CK 5/6 and HBME-1 as mesothelial cell markers; Desmin as marker of benign mesothelial cells; Claudin 4 as epithelial marker and CK7/CK20 as a marker of metastasis. Malignancy was confirmed by histologic evaluation; non-malignant conditions were confirmed by histopathology or follow up. Sensitivities, specificities, predictive values and accuracy were calculated.
Results: CK5/6 demonstrated a high specificity (100%) for mesothelium. For the detection of canine and feline mesothelial cells the coexpression of panCK and VIM displayed the best sensibility (94,1%) while HBME-1 was the antibody that presented highest accuracy. Claudin 4 demonstrated a very low sensibility versus canine and feline epithelial cells.
Conclusion: The most specific marker, with for the identification of mesothelial cells in canine and effusion, is the Vim/CK coexpression, being CK5/6 the most specific and HBME-1 the marker with the highest overall accuracy. Desmin is a useful marker in discriminating between benign and malignant mesothelial cells. The coordinate expression of CK7/CK20+ has not proved to be useful on the identification of metastatic cells on effusion. The study of Claudin 4 necessitate to be deepened in veterinary medicine. In conclusion, the combination of both cytology and immunohistochemistry studies can greatly enhance the diagnostic accuracy, sensitivity and specificity in malignant effusions.
10
Wilson, Rachel. "The developmental consequences of otitis media with effusion". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273453.
Pełny tekst źródła
11
Oguntade, Habeeb Idowu. "Modelling of gas turbine film and effusion cooling". Thesis, University of Leeds, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581946.
Pełny tekst źródłaStreszczenie:
This thesis presents CFD predictions of gas turbine film and effusion cooling. The dearth of detailed experimental adiabatic effusion cooling data led to the validation of the computational procedures against the experimental adiabatic cooling effectiveness data for a single row of inclined round film cooling holes. This showed that the overall best agreement of the CFD predictions with experimental data was for the realizable k-e turbulence model with enhanced wall function. This was also shown to give good predictions of experimental results for trench outlet film cooling. This film cooling CFD work was extended .to demonstrate trench outlet lip geometries that could further improve the cooling effectiveness. The limitation of the CFD model was at higher blowing rates, M, when the film jet lifted off from the surface, where the CFD did not accurately predict the adiabatic cooling effectiveness close to the hole. For attached jets at lower M the agreement was good. The same CFD procedures were used for all the effusion cooling conjugate heat transfer (CHT) predictions. The hot metal wall effusion cooling experimental data base of Andrews and co-workers (1983-1995) was used to validate the CHT effusion cooling predictions. This database was for combustor flat wall cooling with mainly 90° injection holes. The overall effusion cooling effectiveness was measured and this required conjugate heat transfer CFD predictions. The adiabatic film cooling effectiveness was also predicted, by using a gas tracer in the cooling air and predicting its concentration at the effusion wall. For each effusion hole configuration, the coolant mass flow rate, G kg/srrr2bar, was varied from 0.1 to 1.5 and each G required a separate computation. The influence of the number of holes at a constant X!D of 4.6 and the hole size at fixed X were investigated. The agreement between the predictions and experimental data was good. Finally, the influence of the effusion coolant jets flow direction to the hot-gas crossflow on effusion cooling performance was investigated. This included 30° inclined opposed-flow jets effusion wall, which was predicted to be the best effusion jets flow pattern. The addition of the filleted shape trench outlet to effusion cooling was predicted to improve the cooling performance with reduced coolant mass flow rate, due to the improved adiabatic film cooling.
12
Oleshchenko, Halyna Pavlivna, V. P. Voshchenko, Kateryna Andriivna Diedkova, Катерина Андріївна Дєдкова, Екатерина Андреевна Дедкова, Галина Павлівна Олещенко i Галина Павловна Олещенко. "Features of radiodiagnosis of syndrome of pleural effusion". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/48496.
Pełny tekst źródłaStreszczenie:
The epidemic of tuberculosis, registered in Ukraine in 1995, remains a threat to society.
Unfortunately, it cannot be overcomed, despite all the efforts. In the last two decades against the background of a high general incidence of all tuberculosis is more common extrapulmonary localization. Among such form the overwhelming majority - tuberculosis of the pleura. The leading signs of the disease are chest pain, coughing, increasing of
shortness of breath, accumulation of pleural effusion.
13
Miller, Mark W. "Heat transfer in a coupled impingement-effusion cooling system". Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4807.
Pełny tekst źródłaStreszczenie:
The efficiency of air-breathing gas turbine engines improves as the combustion temperature increases. Therefore, modern gas turbines operate at temperatures greater than the melting temperature of hot-gas-path components, and cooling must be introduced in order to maintain mechanical integrity of those components. Two highly effective techniques used in modern designs for this purpose are impingement cooling and use of coolant film on hot-gas-path surface introduced through discrete film or effusion holes. In this study, these two mechanisms are coupled into a single prototype cooling system. The heat transfer capability of this system is experimentally determined for a variety of different geometries and coolant flow rates. This study utilizes Temperature Sensitive Paint (TSP) in order to measure temperature distribution over a surface, which allowed for local impingement Nusselt number, film cooling effectiveness, and film cooling heat transfer enhancement profiles to be obtained. In addition to providing quantitative heat transfer data, this method allowed for qualitative investigation of the flow behavior near the test surface. Impinging jet-to-target-plate spacing was varied over a large range, including several tall impingement scenarios outside the published limits. Additionally, both in-line and staggered effusion arrangements were studied, and results for normal injection were compared to full coverage film cooling with inclined- and compound-angle injection. Effects of impingement and effusion cooling were combined to determine the overall cooling effectiveness of the system. It is shown that low impingement heights produce the highest Nusselt number, and that large jet-to-jet spacing reduces coolant flow rate while maintaining moderate to high heat transfer rates. Staggered effusion configurations exhibit superior performance to in-line configurations, as jet interference is reduced and surface area coverage is improved. Coolant to mainstream flow mass flux ratios greater than unity result in jet blow-off and reduced effectiveness. The convective heat transfer coefficient on the film cooled surface is higher than a similar surface without coolant injection due to the generation of turbulence associated with jet-cross flow interaction.ID: 030646180; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; .; Thesis (M.S.M.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 171-176).
M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Thermo-Fluids Track
14
Chakraborty, Kanishka, John B. Bossaer, R. Patel i K. Krishnan. "Successful Treatment of Nilotinib-Induced Pleural Effusion with Prednisone". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2318.
Pełny tekst źródłaStreszczenie:
Chronic myeloid leukemia is characterized by a unique reciprocal translocation between chromosomes 9 and 22 resulting in deregulated tyrosine kinase activity. Tyrosine kinase inhibitors, such as imatinib, dasatinib, and nilotinib have revolutionized treatment of Chronic myeloid leukemia. However, tyrosine kinase inhibitors? use has presented new challenges in managing both acute and chronic toxicities, particularly ?off-target? toxicities like pleural effusion. Pleural effusions are seen less often with imatinib and very rarely with nilotinib. A 66-year-old male presented to emergency department with complaints of mild chest pain and dyspnea of 3 days duration with progressive worsening, including dyspnea at rest. Patient was currently taking nilotinib after failing imatinib for chronic myeloid leukemia. Nilotinib was put on hold. After exclusion of cardiac and pulmonary etiologies patient was treated for community acquired pneumonia with minimal improvement. Despite the very low incidence of pleural effusion with nilotinib (<1%), he was started on 20?mg of prednisone PO for 3 days. Patient had a dramatic improvement within 48?h after beginning prednisone. This treatment approach suggests that pleural effusions associated with nilotinib can be successfully treated in the same way as pleural effusions associated with dasatinib.
15
Koivunen, P. (Petri). "Otitis media in children:detection of effusion and influence on hearing". Doctoral thesis, University of Oulu, 1999. http://urn.fi/urn:isbn:9514252314.
Pełny tekst źródłaStreszczenie:
Abstract
This study was undertaken to improve the diagnosis of otitis media and to investigate possible hearing loss caused by middle ear effusion (MEE) in small children.
The accuracy of minitympanometry in detecting MEE was evaluated in 162 children. The finding was compared with the amount of effusion found in myringotomy. Minitympanometry proved to be an accurate method to detect MEE in young children, the sensitivity and specificity values being 79% and 93% in cooperative children but it had no value in non-cooperative children. Minitympanometric examination could be performed successfully with good cooperation in 87% of a total of 206 children in paediatric outpatient clinic.
Impaired mobility of the tympanic membrane (TM) was the best sign of MEE in pneumatic otoscopy of 76 children, with sensitivity and specificity values of 75% and 90%, respectively.
The influence of nitrous oxide (N2O) on MEE was tested by weighting the effusion found in myringotomy during general anaesthesia with and without N2O in 39 and 37 children, respectively. The mean weight of the effusion in the oxygen-air group did not differ from the weight in the N2O group, and thus peroperative findings in myringotomy are reliable.
Studies on symptomatology and the temporal development of acute otitis media (AOM) during upper respiratory tract infection (URI) were based on three-month follow-up of 857 children. Symptoms of URI only were compared with symptoms of URI complicated by AOM in the same child in 138 children. The most important symptom associated with AOM was earache, with a relative risk of 21.3. Sore throat, night restlessness and fever at days 3-6 were also significantly associated with AOM, with relative risks of 3.2, 2.6 and 1.8, respectively. In 44 children under two years of age, earache, conjunctival symptoms and cloudy rhinitis were significantly associated with AOM.
Temporal development of AOM was assessed from 250 episodes in 184 children. Sixty-three per cent of cases of AOM occurred during the first week after the onset of URI, peaking on days 2 to 5. The onset of AOM in children with a history of recurrent episodes of AOM did not differ from that in those who had experienced only a few episodes of AOM. No individual tendency was noticed among children suffering more than one AOM episode during follow-up.
To assess the influence of the quantity and quality of MEE on hearing in small children, transient evoked otoacoustic emission (TEOAE) was performed under general anaesthesia before myringotomy in 185 ears of 102 children. Reduced TEOAEs indicating hearing loss were found in 83% of the ears with mucoid effusion and in 56% of the ears with non-mucoid effusion, the difference being statistically significant (p < 0.01). A significant negative correlation between the reproducibility of TEOAE responses and the amount of effusion was found (Spearman rank correlation coefficient r = -0.589, p < 0.001). Findings in minitympanometry correlated with the responses of TEOAE.
Although parents are able to predict AOM quite reliably, various symptoms and the duration of URI seems to be of little value in helping the diagnosis of AOM. Detection of effusion in OM may be improven by minitympanometry in cooperative children. Any kind of effusion may cause hearing loss in small children, which must be considered when treating OM.
16
Minai, Zaiem Hamed. "Evaluation of active acoustic methodology in diagnosis of pleural effusion". Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80252.
Pełny tekst źródłaStreszczenie:
Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Pleural effusion is a common respiratory condition that is characterized by an abnormal collection of fluid in the lung cavity. In this study, an innovation using the transmission of sound into the respiratory system as a novel tool to detect fluid in the lung was developed. First, the method was evaluated on a phantom model of a lung. Based on the results of this test model, the appropriate technique was used in a clinical study. This method has several advantages, such as that is non-invasive, low cost, and easy for clinical review. Two techniques, including analysis of the frequency response of the model and the transient time of transmitted sound in the lung, were evaluated in the phantom models of the human lung. Two phantom models with similar geometry to the human lung, including a healthy model (without fluid in the model) and a pleural effusion model (with bulk of fluid in the model) were developed. These models have acoustical properties similar to the lung parenchyma. To obtain the frequency responses of the model, a sine sweep signal was transmitted into the model and the frequency response of the model was then calculated using the fast Fourier transform. The transient time of the transmitted sound was calculated using a cross correlation method. The results show that the locations of fluid in the model were detectable using both techniques. However, the transient time technique is better than the frequency response technique because it is simple, fast, and has potential for use in a clinical enviorment. Based on the results obtained from the phantoms, the transient time method was performed on both 22 healthy participants and four patients diagnosed with pleural effusion. To perform this technique on human subjects, a data acquisition system was developed. Two types of sound, including a complex chirp sound and a polyphonic sound, were transmitted into the respiratory systems of the participants. The time delay between a reference microphone, located on the trachea of the subject, and eight microphones attached to the chest was computed using a cross correlation method, and the effect of inhalation and lung size on the transient time of transmitted sound on the healthy subject was evaluated. The results show that using transmission of sound in the lung is a promising technique in the diagnosis of pleural effusion.
AFRIKAANSE OPSOMMING: Pleurale effusie is 'n algemene respiratoriese toestand wat gekenmerk word deur 'n abnormale versameling van vloeistof in die longholte. In hierdie studie is 'n innoverende manier ontwikkel om vloeistof in die long met behulp van die transmissie van klank te bespeur. Die metode is eers op 'n fantoommodel van 'n long geëvalueer. Op grond van die resultate van hierdie toetsmodel is die geskikte tegniek in 'n kliniese studie gebruik. Hierdie metode het verskeie voordele, soos dat dit ingreepsvry is, nie duur is nie en kliniese evaluering moontlik maak. Twee tegnieke, naamlik ontleding van die frekwensierespons van die model en die oorgangstyd van versende klank in die long, is in die fantoommodel van die menselong geëvalueer. Twee fantoommodelle met soortgelyke geometrie aan die menselong, met inbegrip van 'n gesonde model (sonder vloeistof in die model) en 'n pleurale-effusie-model (met 'n massa vloeistof in die model), is ontwikkel. Hierdie modelle het akoestiese eienskappe soortgelyk aan die longparenchiem. Om die frekwensieresponse van die model te verkry, is 'n sinuskrommesein tot in die model versend. Die frekwensierespons van die model is met behulp van die vinnige Fourier-transformasie bereken. Die oorgangstyd van die versende klank is deur 'n kruiskorrelasie-metode bereken. Die resultate toon dat die ligging van die vloeistof in die model met albei tegnieke bespeur kan word. Die oorgangstyd-tegniek is egter beter as die frekwensierespons-tegniek, aangesien dit eenvoudig en vinnig is en maklik in 'n kliniese omgewing gebruik kan word. Op grond van die resultate wat van die fantome verkry is, is die oorgangstyd-metode op 22 gesonde deelnemers en vier pasiënte wat met pleurale effusie gediagnoseer is, uitgevoer. 'n Dataverkrygingstelsel is ontwikkel ten einde hierdie tegniek op proefpersone uit te voer. Twee soorte klank, naamlik 'n komplekse tjirpgeluid en 'n polifoniese klank, is na die respiratoriese stelsels van die deelnemers versend. Die tydvertraging tussen 'n verwysingsmikrofoon in die tragea van die proefpersoon en agt mikrofone wat aan die bors vasgeheg is, is met 'n kruiskorrelasie-metode bereken, en die uitwerking van inaseming en longgrootte op die oorgangstyd van versende klank op die gesonde proefpersone is geëvalueer. Die resultate toon dat die gebruik van transmissie van klank in die long 'n belowende tegniek vir die diagnose van pleurale effusie is.
17
Sobol, Steven E. "Th2 cytokine expression in atopic children with otitis media with effusion". Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33031.
Pełny tekst źródłaStreszczenie:
Background. Otitis media with effusion (OME) is more common in atopic children. Few studies have looked for the presence of inflammatory mediators in the middle ear effusions of this population.Objectives. We hypothesize that atopic children with OME have a different inflammatory cell and cytokine profile than non-atopic children with the disease.
Methods. The atopic status of 26 children with OME was determined. Using immunocytochemistry, fluid specimens were assessed for T lymphocytes, eosinophils, neutrophils, mast cells, and basophils. The expression of IL-4, II.-5, and IFN-gamma mRNA was assessed using in-situ hybridization.
Results. There is a higher percentage of eosinophils, T lymphocytes and cells expressing IL-4 and IL-5 mRNA in atopic children (n = 8) compared to non-atopic controls (n = 18) (p < 0.01).
Conclusion. The predominance of eosinophils, T lymphocytes and Th2 mediators in the middle ear effusions of atopic children provides strong evidence that atopy plays a role in the pathogenesis of this condition.
18
Gonçalves, Jessica de Souza. "Derrames pleurais e abdominais e a sua classificação : estudo de 25 casos". Bachelor's thesis, Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária, 2011. http://hdl.handle.net/10400.5/3572.
Pełny tekst źródłaStreszczenie:
Dissertação de Mestrado Integrado em Medicina VeterináriaOs derrames cavitários consistem em acumulações anormais de líquido de natureza variada ou gás/ar dentro das cavidades corporais, tais como as cavidades pleural, peritoneal, pericárdica, articular. Neste trabalho, vão ser apenas abordados os derrames cavitários pleural e peritoneal, uma vez que foram os registados com maior frequência durante o estágio curricular. O diagnóstico etiológico é baseado nas informações obtidas na anamnese, no exame físico e nos exames complementares, tais como hemograma, bioquímicas, imagiologia e análise do líquido do derrame, normalmente colhido por toraco ou abdominocentese. As análises bioquímica e citológica permitem classificar os derrames em transudado, transudado modificado ou exsudado e representam um dos componentes mais importantes de diagnóstico, uma vez que auxiliam na identificação da fisiopatologia responsável pela acumulação do líquido e podem indicar a necessidade de realização de novos exames complementares. O estudo de caso teve como objectivo a caracterização de uma amostra de 25 casos de animais diagnosticados com derrames pleural ou peritoneal de acordo com a espécie, a localização do derrame, os sinais clínicos observados, os meios de diagnóstico utilizados, a classificação do derrame e a etiologia subjacente. Após análise dos dados recolhidos, à excepção dos derrames hemorrágicos e gasosos, foi possível confirmar a importância da classificação do derrame com base nas análises bioquímica e citológica, uma vez que permitiu chegar a um diagnóstico, principalmente nos casos de derrames neoplásicos, ou orientar a realização de outros exames complementares. Nos canídeos, a principal causa de derrame pleural e peritoneal observada foi a neoplásica. Nos felídeos, o mesmo se verifica nos derrames pleurais, com destaque para o linfoma mediastínico, enquanto na maioria dos derrames peritoneais o diagnóstico foi de PIF. Relativamente aos casos de derrames gasosos, registou-se um caso de pneumotórax traumático aberto e um caso de pneumoperitoneu por ruptura intestinal por corpo estranho, ambos em cães, e apenas um caso de pneumoperitoneu em gato por ruptura do ducto colédoco e intestino delgado com forte suspeita de etiologia traumática.
Dissertação de Mestrado Integrado em Medicina Veterinária
ABSTRACT - Pleural and abdominal effusions and its classification: A study of 25 cases - Cavity effusions consist of abnormal accumulations of fluid of varied nature or gas/air inside body cavities, for example, pleural, abdominal, pericardial and joints. In this work, only pleural and peritoneal effusions will be approached, since these were the two most frequent presentations registered in the clinics. The diagnosis of the underlying etiology was based on information collected from the anamnesis, physical examination and complementary exams such as complete blood count, biochemistry, imaging techniques and analysis of the effusion’s, usually collected by toraco or abdominocentesis. Both biochemical and cytological analysis of these fluids enables its classification into transudate, modified transudate or exudates, and represent one of the most important components for a diagnosis, since it allows the identification of the pathological process responsible for liquid accumulation, and can indicate the need to perform more investigation proceedings. The objective of this study case was to characterize a sample of 25 animals diagnosed with pleural or abdominal effusion, by species, effusion’s location, clinical signs, means of diagnosis applied, effusion classification and underlying etiology. After analyzing the collected data, with exception of hemorrhagic and gaseous effusions, it was possible to confirm the capital importance of the effusion’s classification based on biochemical and cytological analysis once it led to a diagnosis, mainly in cases of neoplastic effusion, or oriented the need to perform auxiliary tests. In dogs, the main cause observed for pleural and peritoneal effusion was of neoplastic nature. The same was in cats concerning pleural effusions, principally mediastinal lymphoma, while the majority of peritoneal effusions where linked to a diagnosis of infectious peritonitis. Concerning gaseous effusions, one case of traumatic open pneumothorax and other of pneumoperitoneum elicited by intestinal rupture by a foreign body, were documented in dogs, and only one case in a cat was documented, of pneumoperitoneum caused by a rupture of the common bile duct and small intestine, with possible traumatic etiology.
19
Nguyen, Ha-Nam Phan 1975. "Evidence linking allergic otitis media with effusion to the United airways concept". Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80341.
Pełny tekst źródłaStreszczenie:
Otitis media with effusion (OME) is a chronic inflammatory disease of the middle ear space characterized by the accumulation of fluid. Previous investigations have found the composition of the inflammatory substrate in effusions of allergy-associated otitis media to be is similar to the late-phase allergic response seen elsewhere in the respiratory tract, such as in asthma and in allergic rhinitis. In addition, there is evidence suggesting that diseases of the upper and lower airways may represent different clinical manifestations of a single inflammatory airway syndrome, or the United Airway Concept. The objective of this research is to determine if the middle ear compartment may be a component of the United Airways in allergic disease. Middle ear fluid, torus tubaris (Eustachian tube mucosa at the nasopharyngeal orifice) and adenoidal tissue biopsies were obtained from 45 patients undergoing simultaneous tympanostomy tube placement for OME and adenoidectomy for adenoid hypertrophy. The cellular and cytokine profiles of each site were investigated using immunocytochemistry (elastase, CD3, MBP) and in-situ hybridization (IL-4, IL-5, IFN-gamma mRNA). Atopic status was determined for each patient using skin-prick testing. Eleven of the 45 patients with OME (24%) were atopic. The MEE of atopics had significantly higher levels of eosinophils, T lymphocytes, IL-4 and IL-5 mRNA +cells (p < 0.01), and significantly lower levels of neutrophils and IFN-gamma mRNA +cells (p < 0.01) when compared to non-atopics. The nasopharyngeal tissue biopsies also revealed similar cellular and cytokine profiles. Therefore, the allergic inflammation in atopic patients with OME occurs on both sides of the Eustachian tube, both in the middle ear and in the nasopharynx. The results of this study support the concept that the middle ear may be part of the United Airway in atopic individuals.
20
Mahmoud, Ruba Faisal Ghazi. "Association between arthralgia and imaging findings of effusion in the temporomandibular joints". Thesis, State University of New York at Buffalo, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1566927.
Pełny tekst źródłaStreszczenie:
The temporomandibular joint (TMJ) complex consists of the condyle, articular eminence, and articular disc. This disc divides the intracapsular components of the joint into upper and lower joint spaces. Magnetic resonance imaging (MRI) is considered the reference standard for soft tissue diagnosis of the TMJ. One aim of the study was to identify if an association exists between arthralgia of the TMJ and MRI identified joint effusion.
The clinical significance of identifying the presence of TMJ effusion on MRI lies in its potential association with inflammation, clinically assessed as pain at the lateral TMJ pole or around the pole area. Unfortunately the literature has been divided in asserting whether pain in the joint area is associated with the presence of MRI assessed effusion. A systematic review of the literature was unable to provide conclusive evidence for or against an association between TMJ pain and effusion.
Materials and methods: Clinical and imaging findings from 336 joints were obtained from a historical cohort involving individuals with temporomandibular disorders. Two by two tables of association were used to determine if clinical signs associated with arthralgia were associated with the presence of ipsilateral effusion in the TMJ. These clinical signs included pain on range of motion (maximum unassisted and assisted opening as well as excursive movements), TMJ manipulation (compression and translation), and palpation of the lateral pole of the TMJ and around the TMJ pole. In addition, a total pain score (range 0-7) was created which represented the sum of positive responses to pain on any of the clinical range of motion tests. Statistical testing included the T-test to test for possible association of joint effusion with any pain to these clinical measures.
Results: Statistical tests of association between joint effusion and range of motion, excursions, protrusion, joint manipulation and palpation all had p values > .05.
Conclusion: The results suggest that there is no statistically significant association between an MRI diagnosis of joint effusion and TMJ arthralgia.
21
Wolff, Trent M. "The Effect of Particle Size on Deposition in an Effusion Cooling Geometry". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1523800099698799.
Pełny tekst źródła
22
Talukder, Mohammad Osman Gani. "A study of sputtered a-Si:H by thermal effusion and infrared spectroscopy". Thesis, Talukder, Mohammad Osman Gani (1991) A study of sputtered a-Si:H by thermal effusion and infrared spectroscopy. PhD thesis, Murdoch University, 1991. https://researchrepository.murdoch.edu.au/id/eprint/51626/.
Pełny tekst źródłaStreszczenie:
Hydrogenated amorphous silicon, a-Si:H, is an exciting new material with ideal properties for various types of optoelectronic devices including photovoltaic cells. It is well known that the quality of an a-Si:H alloy, for such an application, is closely related to its hydrogen content and to the nature of the silicon-hydrogen bonds. On the other hand, a-Si:H films often contain a significant amount of unintentionally incorporated impurities such as oxygen and nitrogen which significantly influence their optoelectronic properties. Hence, the main objective of this work is to study the various bonding configurations involving Si, H, 0 and N in the a-Si network.
Infrared spectroscopy and thermal hydrogen effusion have been used to study the nature of the silicon-hydrogen, silicon-oxygen and silicon-nitrogen bonds in sputtered a-Si:H alloys. The samples were prepared by reactive radio frequency sputtering under different deposition conditions to produce hydrogen contents ranging from 12 to 35 at.%. Slightly contaminated samples were found to contain nitrogen and oxygen concentrations ranging from 0.0 to -1.5 and 0.0 to -3.0 at.% respectively. Samples were deposited onto crystalline silicon (100) substrates at a deposition rate of -4.0 nm/min and a substrate temperature of -120 °C with thicknesses ranging from -0.08 to 0.6 ^m. Some samples were annealed in vacuum or in a hydrogen atmosphere, for up to 60 minutes, at various temperatures in the 150-550 °C range.
Infrared absorption spectra, from 370 to 5000 cm- i were obtained using a fourier transform infrared spectrometer. A computer program based on the simplex algorithm was then used to deconvolute the component peaks in the Si-H bending and stretching bands of these spectra. The thermal effusion spectra were obtained by heating the samples up to 800 °C at a rate of 60 - 100 °C/min., in a vacuum system with a base pressure of -10"9 Torr, and using a quadrupole mass spectrometer to monitor the hydrogen evolution.
For the as-deposited samples: (i) The infrared results demonstrate that the oscillator strengths for the Si-H bending and stretching bands depend on the hydrogen, oxygen and nitrogen concentrations, (ii) The thermal effusion spectra show three peaks, two at -325 and 450 ° C due to weakly bonded hydrogen and the other at 725 °C due to tightly bonded hydrogen. The first low temperature peak is absent for samples with a multi-oxide layer on or near the surface region.
Our results demonstrate that annealing produces a redistribution and transformation of different bonding configurations involving Si, H, 0 and N. Features observed in the thermal effusion and infrared spectra resulting from heat treatment have been compared and thus correlated with different groups of Si and H.
The results have enabled us to propose a self consistent model of the behaviour of hydrogen, oxygen and nitrogen in amorphous silicon. It is concluded that this model in conjunction with some electrical and optical characterisations can lead us to better understanding the role of hydrogen in a-Si:H.
23
Park, Jihong. "Neuromechanical Alterations Due to Induced Knee Pain and Effusion During Functional Movements". BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/3182.
Pełny tekst źródłaStreszczenie:
Purpose: Examine neuromechanical alterations due to isolated and/or combined knee pain and effusion in functional movements. Methods: A 4X3 randomised controlled laboratory study with repeated measures was used. Nineteen, healthy volunteers (age: 22.4 ± 2.4 years) underwent four different treatments (control, effusion, pain, and pain/effusion) with a week wash out period. Ten near-infrared cameras with 43 reflective markers, 12 surface EMG electrodes, and two ground-embedded force platforms were used to record neuromechanical changes during functional movements (walking and drop landing). To induce pain, 5% sodium chloride (1 ml) was injected into the infrapatellar fat pad. To induce effusion, 0.9% sodium chloride (50 ml) was injected into the knee joint capsule. To induce pain/effusion, both injections were employed. No injection was used for the control. Subjects performed walking and a single leg drop landing in three time intervals: precondition (prior to injection), condition (immediate post injection), and postcondition (30 min post injection). To quantify pain perception, the visual analogue scale was measured every two minutes. Results: Under pain/effusion treatment, subjects walked slowly with a shorter stride length. Joint moments of plantarflexion, knee extension, knee abduction, and hip abduction were reduced. Subjects also showed a decrease at 20% and 80% of stance phase, and an increase in 50% in vertical ground reaction force (VGRF). Under the same treatment, subjects landed with a less peak VGRF with increased time to peak VGRF, alterations of joint angles (ankle dorsiflexion, knee extension, and hip adduction), and moments (knee extension, knee abduction, and hip abduction). Conclusions: Joint pain and effusion cause neuromechanical alterations in the lower extremity during functional movements. These compensatory strategies may alter joint loading, potentially resulting in acceleration of the joint degenerative process. We also recommend use of crutches following injury to avoid modifications of movement strategies.
24
Wilson, David Andrew. "The vapour pressure of pharmaceutical solids as determined by dynamic Knudsen effusion technique". Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437246.
Pełny tekst źródła
25
Hogan, Sarah Cecilia Mary. "The development of hearing in children : some effects of otitis media with effusion". Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301869.
Pełny tekst źródła
26
Guo, Li. "Studies into mucin and its regulation in pathogenesis of otitis media with effusion". Thesis, University of Nottingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517658.
Pełny tekst źródła
27
Viswanathan, Harishnath. "Mucin Gene Expression and GastricReflux in Chronic Rhinosinusitis and Otitis Media with Effusion". Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499336.
Pełny tekst źródła
28
Smith, Brandon. "Simulation of Heat/Mass Transfer of a Three-Layer Impingement/Effusion Cooling System". Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5509.
Pełny tekst źródłaStreszczenie:
Cooling techniques for high density electrical components and electronic devices have been studied heavily in recent years. The advancements in the electrical/electronic industry have required methods of high heat flux removal. Many of the current electrical components and electronic devices produce a range of heat fluxes from 20 W/cm2 – 100 W/cm2. While parallel flow cooling systems have been used in the past, jet impingement is now more desirable for its potential to have a heat transfer coefficient 3-5 times greater than that of parallel flow at the same flow rate. Problems do arise when the jet impingement is confined and a cross flow develops that interacts with impinging jets downstream leading to a decrease in heat transfer coefficient. For long heated surfaces, such as an aircraft generator rotor, span wise fluid management is important in keeping the temperature distribution uniform along the length of the surface. A detailed simulation of the heat/mass transfer on a three-layer impingement/effusion cooling system has been conducted. The impingement jet fluid enters from the top layer into the bottom layer to impinge on the heated surface. The spent fluid is removed from the effusion holes and exits through the middle layer. Three different effusion configurations were used with effusion diameters ranging from 0.5 mm to 2 mm. Temperature uniformity, heat transfer coefficients, and pressure drops were compared for each effusion diameter arrangement, jet to target spacing (H/d), and rib configuration. A Shear Stress Transport (SST) turbulence fluid model was used within ANSYS CFX to simulate all design models. Three-layer configurations were also set in series for long, rectangular heated surfaces and compared against traditional cooling methods such as parallel internal flow and traditional jet impingement models. The results show that the three-layer design compared to a traditional impingement cooling scheme over an elongated heated surface can increase the average heat transfer coefficient by 75% and reduce the temperature difference on the surface by 75%. It was shown that for a three layer design under the same impingement geometry, the average heat transfer coefficient increases when H/d is small. The inclusion of ribs always provided better heat transfer and centralized the cooling areas. The heat transfer was increased by as much as 25% when ribs were used. The effusion hole arrangement showed minimal correlation to heat transfer other than a large array provides better results. The effusion holes' greatest impact was found in the pressure drop of the cooling model. The pressure losses were minimal when the effective area of effusion holes was large. This minimizes the losses due to contraction and expansion.M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Thermofluids
29
Johnson, Ian J. M. "Otitis Media with Effusion - investigation into aspects of rheology biochemistry and inflammatory mediators". Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287845.
Pełny tekst źródła
30
Martin, Damian. "Effects of high intensity, large-scale free-stream turbulence on combustor effusion cooling". Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/14725.
Pełny tekst źródłaStreszczenie:
Full-coverage or effusion cooling is commonly used in the thermal management of gas turbine combustion systems. The combustor environment is characterised by highly turbulent free-stream conditions and relatively large turbulent length scales. This turbulent flow field is predominantly created by the upstream fuel injector for lean burn systems. In rich burn systems the turbulent flow field is augmented further by the addition of dilution ports. The available evidence suggests that large energetic eddies interact strongly with the injected coolant fluid and may have a significant impact on the film-cooling performance. The desire to create compact low-emission combustion systems with improved specific fuel consumption, has given rise to a desire to reduce the quantity of air used in wall cooling, and has led to the need for improved cooling correlations and validated computational methods. In order to establish a greater understanding of effusion cooling under conditions of very high free-stream turbulence, a new laboratory test facility has been created that is capable of simulating representative combustor flow conditions, and that allows for a systematic investigation of cooling performance over a range of free-stream turbulence conditions (up to 25% intensity, integral length scale-to-coolant hole diameter ratios of 26) and coolant to mainstream density ratios (??_c/??_??? ???2). This thesis describes this new test facility, including the method for generating combustor relevant flow conditions. The hot side film cooling performance of cylindrical and fanned hole effusion has been evaluated in terms of adiabatic film-cooling effectiveness and normalised heat transfer coefficient (HTC) and heat flux reduction (HFR). Infrared thermography was employed to produce spatial resolved surface temperature distributions of the effusion surface. The analysis of this data is supported by fluid temperature field measurements. The interpretation of the data has established the impact of turbulence intensity, integral length scale and density ratio on the mixing processes between free-stream and coolant flows. Elevated levels of free-stream turbulence increase the rate of mixing and degrade the cooling effectiveness at low blowing ratios whereas at high blowing ratios, where the coolant detaches from the surface, a modest increase has been observed under certain conditions; this is due to the turbulent transport of the detached coolant fluid back towards the wall. For angled cylindrical hole injection the impact of density ratio as an independent parameter was found to be relatively weak. Adiabatic effectiveness data gathered at DR's of 1 - 1.4 scaled reasonable well when plotted against momentum flux ratio. This suggests data collected at low DR's can be scaled to engine representative DR's. The investigation of shaped cooling holes found fanned effusion has the potential to dramatically improve film effectiveness. The diffusion of the flow through a fanned exit prevented jet detachment at blowing ratios up to 5, increasing spatially averaged effectiveness by 89%.
31
Campolina, França Geraldo Agosto. "Contribution à l'étude des écoulements pariétaux avec effusion : application au refroidissement de parois". Lyon, INSA, 1996. http://www.theses.fr/1996ISAL0060.
Pełny tekst źródłaStreszczenie:
Ce travail comporte deux parties. Dans la première partie, nous présentons une extension de la méthode de Nachtsheim et Swigert pour la résolution des équations de la couche limite des écoulements laminaires externes, bidimensionnels ou axisymétriques, avec ou sans effusion, dans les cas de profils de vitesses non semblables, en présence ou non de gradient de pression. On tient compte des propriétés variables des deux fluides de nature différente en écoulement non isotherme. L'efficacité de la méthode généralisée est vérifiée sur quatre cas d'écoulements laminaires. La deuxième partie du travail est consacrée à l'étude théorique et expérimentale de l'écoulement turbulent isotherme et non isotherme d'air dans une veine de section rectangulaire avec ou sans injection d'air à travers une paroi poreuse qui constitue une partie du plancher de la veine. On étudie notamment : l'influence du taux d'injection, du gradient longitudinal de pression et de l'intensité de turbulence sur les profils des vitesses et sur les transferts pariétaux de quantité de mouvement et d'énergie dans l'écoulement. On présente également le choix du modèle de turbulence pour la modélisation bidimensionnelle de l'écoulement dans la veine, la modélisation thermique et hydrodynamique de la paroi poreuse et le couplage thermique et hydrodynamique entre l'écoulement principal et la paroi poreuseThis work includes two parts. In the first part, we present an extension of the Nachtsheim and Swigert method’s for the resolution of the laminar boundary layers of the two-dimensional or axisymmetric external flows, with or without injection and in presence or not of a pressure gradient. The properties variations of the two fluids of different chemical nature are taken into account in the nonisothermal flow. The efficiency of the generalized method is validated on five cases of laminar flow. The second part of the work deals with the theoretical and experimental studies of the turbulent isothermal or nonisothermal air flow within a channel of rectangular section with or without air injection through a porous part of the channel floor. One studies particularly: the influence of injection rate, longitudinal pressure gradient and turbulence intensity on the velocity profiles and on the momentum and energy transfers within the boundary layer. We present also the choice of the turbulence model for the thermal and dynamic two-dimensional modelling of the main air flow in the channel coupled with the secondary flow through the porous wall
32
El-Jummah, Abubakar Mohammed. "Impingement and impingement/effusion cooling of gas turbine components : conjugate heat transfer predictions". Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/9025/.
Pełny tekst źródłaStreszczenie:
Conjugate heat transfer (CHT) and computational fluid dynamics (CFD) were combined in this work using ICEM meshing and ANSYS Fluent software. Block-structured grids with hexahedral elements were used to investigates the key features of impingement cooling of gas turbine metal surfaces, with applications to combustor wall, nozzle and turbine blade cooling. Only flat wall cooling was investigated and not any influence of surface curvature. Combustor wall and turbine blade flank cooling both approximate to a flat wall as the hole diameter and pitch are all small in relation to the combustor or blade curvature. Also the experimental data base on impingement cooling predominantly uses a flat wall. The aim was to validate the computations against experimental data from hot metal wall research facilities and then to use the validated computational methodology to predict improved cooling geometries. Experimental investigations that used hot wall rigs at 770 K cross-flow temperature and 293 K coolant were modelled to predict the overall cooling effectiveness for impingement cooling. The impingement cooling of the metal surface with an equivalent heat flux was modelled, at a hot gas value equals to 100 kW/m2 and is an input relevant to real gas turbine combustor applications of 250 kW/m2K heat transfer coefficient (HTC). Much of the experimental data base with metal walls used electrically heated metal wall experiments with relatively low wall temperatures. These were also modelled using a constant hot gas side temperature and the thermal gradient through the thickness and between impingement and effusion holes were predicted. The work was confined to the internal wall heat transfer and did not investigate the combined film effusion cooling that is often used in combination with impingement cooling. However, the interaction of internal wall effusion cooling with impingement cooling was investigated, so that the whole internal wall cooling could be predicted. The heat transfer in a metal wall with a square array of 90o holes is a subcomponent of impingement and effusion cooling and was part of this study, which was used to evaluate the impact of the CFD turbulence models. The standard k - ɛ turbulence model with standard wall function (WF) for y+ values in the range 30 - 45 showed better agreement with the measured data, where all the flow features were predicted correctly. Also enhanced wall treatment approaches (EWT) were used for y+ values from 1 - 5, but there was no significant improvement in the predictions compared with the standard wall function approach. All the turbulence models available in Fluent were investigated for an array of holes in a metal wall, which involves only a computation of one hole that is classic short hole or pipe entry length heat transfer. Many of the models could not predict the flow separation and reattachment within a hole L/D of ~1 and as this was fundamental to both effusion and impingement heat transfer, indicating that these models were all poor at the predictions of impingement and impingement/effusions cooling. The experimental data base in impingement heat transfer has results that would not normally be expected and the CHT computations enabled the reason for the experimental trends to be explained. This includes the reduction in heat transfer along the impingement gap influenced by cross-flow, which would be expected to increase the heat transfer. The relatively low effect of turbulence enhancing obstacles in the impingement gap was also predicted. The influence of the number of impingement holes, which leads to methodology to choose a particular hole size has been predicted based on thermal gradients in the metal wall, this helps the designer in choosing optimum number of holes. For impingement cooling with single sided coolant exit from the cross-flow duct, it was shown that the deflection of the cross-flow onto the impingement jet wall surface was a major reason for the deterioration in the impingement target surface heat transfer along the gap. The very limited experimental database for heat transfer to the impingement jet wall surface was well predicted, thus showing that both wall surfaces were important in the overall impingement heat transfer. The design configurations investigated were the hole length, pitch, gap, height and depth to diameter ratios L/D, X/D, Z/D, H/D and E/D respectively. The range of L/D investigated was 0.78 - 4.85, by varying the hole diameter for a fixed metal wall thickness (length) of 6.35 mm. This heat transfer was dominated by thermal and aerodynamic entry length effects including the heat transfer on the hole approach surface. The X/D range investigated was 1.86 - 21.02 by varying D at constant X and also by varying X at constant D, which varies the number of holes per surface area, n. The range of Z/D investigated was from 0.76 - 7.65 at varied and also at a constant Z. The main coolant flow parameter varied was the mass flux G, which is equals to G*/P (kg/sm2bar) in this Ph. D thesis. The requirements for each G with a fixed hole geometry, is a new CHT computation, which is time consuming compared with fairly rapid experimental determinations of the effect of G. The literature survey showed that there were no available detailed flow dynamics investigations of multi-hole impingement cooling. The key experimental measurement that indicates the correctness of the aerodynamic predictions was the pressure loss, which was as a result of the air feed to the impingement gap or effusion hole discharge. The results showed, for the range of geometries, reasonable agreement with the experimental measurements. For heat transfer the experimental measurements were all surface averaged, either for the whole wall or for each row of holes. The predictions were shown to give excellent agreement with surface average heat transfer, which also gave the surface distribution of the heat transfer. It was shown that the surface distribution of heat transfer was directly related to the surface distribution of the turbulence kinetic energy. The experimental influence of turbulence enhancing obstacles in the impingement gap was well predicted. The experimental data base was for one obstacle per impingement hole using two flow configurations: flow parallel to the obstacles, so that the action was to increase the surface area for heat transfer at low blockage increase and flow across the obstacles, so that the action was to increase turbulence and surface area, but at the expense of higher pressure loss. Two obstacles shapes were investigated experimentally, simple continuous ribs and slotted ribs which gave rectangular pin fins relative to the cross-flow, with both turbulence generation and surface area increased. The predictions agreed with the experiments that showed the main effect of the obstacles, for which the deterioration of heat transfer with distance was reduced, but to only have a relatively small (~ 20%) increase in the surface averaged heat transfer. The validated computational procedures were used to investigate other obstacle geometries for the same impingement configuration: surface dimples, round pin-fins and inclined ribs in a zig-zag of ‘W’ format. The zig-zag design predicted an improvement in overall heat transfer compared with the other designs. Impingement/effusion internal wall heat transfer was modelled with one effusion hole per impingement hole and a fixed 8 mm gap. It was shown that the key interaction effect was to remove any cross-flow from the gap, provided all the impingement air flow went through the effusion holes. This geometry is then only viable for low coolant mass flow rates and thus the modelling was confined to low G. This limitation of coolant flow was because effusion cooling improves if the hole velocity is low relative to the cross-flow, which occurs at low mass flow rates.
33
Peravali, Anil. "PRELIMINARY STUDY ON THE IMPACT OF IMPINGEMENT ON THE EFFECTIVENESS OF FILM COOLING IN THE PRESENCE OF GAS PATH PRESSURE GRADIEN". Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4224.
Pełny tekst źródłaStreszczenie:
Impingement is the most commonly used method of cooling in the hot stages of gas turbines. This is often combined with film cooling to further increase the cooling performance. The mainstream flow where in the coolant films discharge often has large stream wise pressure variations. All existing studies on coupled film and impingement cooling concentrated on the effect of the film depletion on the impingement heat transfer. This study investigates the impact of impingement on film cooling, where the jets impinging on a flat plate are depleted through arrays of film cooling holes in the presence of pressure gradient in the main gas path. The main characteristic of the test setup is that there is an impingement wall on the backside of the film effusion wall. The fluid used for both impingement flow and main flow is air. The impingement flow is heated as opposed to the usual practice of heating mainflow, and the array of film holes are configured under the impingement jet hole arrays such that there is no direct impingement on the film holes. The static pressure variations and Mach number (0.01 to 0.3) in the mainstream underneath the flat plate are controlled by inserts with varying flow area. The detailed temperature distribution on the film-covered surface is measured using the Temperature Sensitive Paint (TSP) technique, and film cooling effectiveness is calculated from the measurements. Results are presented for averaged impingement jet Reynolds numbers of 5000 and 8000. The effect of impingement on film effectiveness is studied by comparing the results from the two cases: one where film flow is directly supplied from a plenum and the other where the post- impingement flow is depleted through film effusion holes. The results are presented for cylindrical film cooling holes which are inclined at angles of 20 deg and 30 deg with respect to the target plate surface. The variation of the effectiveness of the film hole arrays along the mainstream are studied in detail. It is observed that the impingement through jet effects the pressure distribution on the target plate with film holes, which in turn affects the blowing rates of each row. The change in the blowing ratios because of a different pressure distribution on the impingement side of the target plate causes the effectiveness to change. From the results it is observed that the farther rows of impingement are affected by the pressure distribution underneath the film holes and have more flow through the film cooling rows, this increases the inlet flow of the films which increase the blowing ratios and in turn decreases the effectiveness of the film cooling holes. The pressure distribution and the change of effectiveness are studied in detail.M.S.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Mechanical Engineering
34
Freeman, Richard A. "Continuous Tracking of Lava Effusion Rate in a Lava Tube at Kilauea Volcano Using Very Low Frequency (VLF) Monitoring". Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2364.
Pełny tekst źródłaStreszczenie:
Measurement of lava effusion rates is a key objective for monitoring basaltic eruptions because it helps constrain geophysical models of magma dynamics, conduit geometry, and both deep and shallow volcano processes. During these eruptions, lava frequently travels through a single "master" lava tube. A new method and instrument for continuously monitoring the crosssectional area of lava streams in tubes and estimating the instantaneous effusion rate (IER) is described. The method uses 2 stationary very low frequency (VLF) radio receivers to measure an unperturbed VLF signal and the influence of highly conductive molten lava on that signal. The difference between these signals is a function of the cross-sectional area of molten lava and the IER. Data from a short test of the instrument are described. This methodology represents a breakthrough in the continuous monitoring of IER because it provides higher temporal resolution than competing methods at a fraction of the cost.
35
McGhee, Scott K. "Evaluation of an uncooled focal plane array thermal imaging camera for effusion cooling research". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0004/MQ45288.pdf.
Pełny tekst źródła
36
Higson, Josephine M. "Parent and professional health beliefs about Otitis media with effusion : impact on parent behaviour". Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299564.
Pełny tekst źródła
37
Yun, Seongseok, Nicole D. Vincelette, Iyad Mansour, Dana Hariri i Sara Motamed. "Late Onset Ipilimumab-Induced Pericarditis and Pericardial Effusion: A Rare but Life Threatening Complication". Hindawi, 2015. http://hdl.handle.net/10150/617198.
Pełny tekst źródłaStreszczenie:
UA Open Access Publishing FundMetastatic cutaneous melanoma has poor prognosis with 2-year survival rate of 10–20%. Melanoma cells express various antigens including gp100, melanoma antigen recognized by T cells 1 (MART-1), and tyrosinase, which can induce immune-mediated anticancer response via T cell activation. Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is an immune check point molecule that negatively regulates T cell activation and proliferation. Accordingly, recent phase III clinical trials demonstrated significant survival benefit with ipilimumab, a human monoclonal antibody (IgG1) that blocks the interaction of CTLA-4 with its ligands. Since the efficacy of ipilimumab depends on T cell activation, it is associated with substantial risk of immune mediated adverse reactions such as colitis, hepatitis, thyroiditis, and hypophysitis. We report the first case of late onset pericarditis and cardiac tamponade associated with ipilimumab treatment in patient with metastatic cutaneous melanoma.
38
Khodahami, Maryam. "Hydrogen uptake during Carburizing and Effusion of Hydrogen at Room Temperature and during Tempering". Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166776.
Pełny tekst źródłaStreszczenie:
The carburizing atmosphere during the case hardening process contains a large proportion of hydrogen. Due to the rapid diffusion of hydrogen a high amount of hydrogen can be absorbed by the carburizing component. The amount of absorbed hydrogen is dependent on some factors such as for example the carburizing time and component dimensions. Hydrogen diffused in material can then cause hydrogen embrittlement and in some cases cause cracking under a static load. This hydrogen must therefore be removed. High amounts of hydrogen diffuse out spontaneously at room temperature. Tempering accelerates the process. The aim of this study was to experimentally measure the amount of absorbed hydrogen after case hardening and hydrogen content after storage at room temperature and also after tempering. The effect of the enriching gas in carburizing furnace on hydrogen absorption was investigated in this study. Three steel grades with different content of alloying elements were used in this investigation. Steel samples were case hardened by gas carburizing and tempering. The hydrogen content analyses included the measurement of hydrogen content before case hardening, after case hardening and after tempering using Leco-RHEN602. Based on the results in this study it was concluded that all steel grades used in this investigation absorb hydrogen during case hardening by gas carburizing. A major part of the absorbed hydrogen is then released by effusion after being stored at room temperature and during tempering. Around 50% of the absorbed hydrogen content during gas carburizing is due to the presence of the enriching gas in the carburizing atmosphere. Around 50 % of hydrogen diffuses out of the steel specimens after one day. It is likely that all of free diffusible) hydrogen has diffused out of the specimens of two steel grades after one week at room temperature or after tempering.Vid sätthärdning består den uppkolande atmosfären till stor del av vätgas och p.g.a. vätets snabba diffusion kan stora mängder av väte absorberas i komponenten. Halten av absorberade väte beror bl.a. på sätthärdningstid och komponentens dimensioner. Väte i materialet kan sedan leda till sprickbildning vid statisk belastning. Detta väte måste därför avlägsnas. En stor del av väte diffunderar ut spontant vid rumstemperatur. Vid anlöpning går processen fortare. Syftet med denna studie var att experimentellt mäta halten av väte som absorberas under sätthärdning, samt efter att metallen har lagrats i luft vid rumstemperatur. Dessutom mättes vätehalten efter anlöpning. Dessutom undersöktes effekten av ugnsatmosfärens tillsatsgas på mängden absorberad väte efter uppkolning. Tre olika höghållfasta och låg legerade stål sorter sätthärdades genom gas uppkolning. Mängden väte analyserades innan sätthärdning, efter sätthärdning, efter lagring i rumstemperatur och efter anlöpning med hjälp av Leco-RHEN602. Enligt resultaten i denna studie, absorberar alla av de tre undersökta stålsorterna väte under sätthärdning. En stor del av det absorberade vätet diffunderar ut efter att stålet har lagrats i luft vid rumstemperatur och under anlöpning. Omkring 50 % av den absorberade vätehalten under uppkolningen är på grund av reaktionen med tillsatsgasen i ugnsatmosfären. Omkring 50 % av vätet diffunderar ut ur proverna efter en dag. Möjligen all fritt (diffunderbart) väte har diffunderat ut ur proverna i två av stålsorterna efter en vecka i rumstemperatur eller efter anlöpning.
39
Arguello, Meztli. "Primary effusion lymphoma : disruption of the B cell transcriptional program and overexpression of inflammatory molecules". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103020.
Pełny tekst źródłaStreszczenie:
Primary Effusion Lymphoma (PEL) is a lymphoproliferative disease of B cell origin associated with HHV-8 infection and characterized by migration of tumor cells to serous body cavities. PEL cells originate from post-germinal center B cells yet harbor a non-B, non-T phenotype, a characteristic that has not been fully explained. In the present study we demonstrate that PEL cells have an impaired expression of B cell-specific transcription factors and this results in a decreased activity of promoters regulating essential B cell genes. PEL cells lack PU.1 expression, although its transcription partner IRF-4 is highly upregulated, leading to decreased activity of the immunoglobulin lambda and kappa light chain ETS-IRF enhancers. Expression of the B cell specific transcription factor Oct-2 and the B cell specific co-activator of octamer factors (Bob-1), which are known to regulate PU.1 expression, was also impaired. Ectopic expression of Oct-2 was able to fully restore PU.1 promoter activity in the PEL cell line BCBL-1, while PU.1 expression also reconstituted the activation of the lambdaB Ets-IRF site. In addition, protein levels of BSAP/Pax-5 and IRF-8/ICSBP were undetectable in PEL cells. The pattern of transcription factor ablation observed in PEL was found to be comparable to that observed in classical Hodgkin's disease-derived cell lines, which also lack B cell specific surface markers. Comparative analysis of gene expression by cDNA microarray of BCBL-1 cells (PEL), L-428 (cHD) and BJAB cells revealed a subset of genes that were differentially expressed in PEL cells. Among these, four genes involved in cell migration and chemotaxis were strongly upregulated in PEL cells: LTA4H, IL-16, TSP-1, and selectin-P ligand. Upregulation of LTA4H was investigated at the transcriptional level. The LTA4H promoter exhibited 50% higher activity in BCBL-1 cells than in BJAB or L-428 cells. Deletion analysis of the LTA4H promoter revealed a positive cis regulatory element active only in BCBL-1 cells in the promoter proximal region located between -76 to -40 bp. Formation of a specific DNA-protein complex in this region was confirmed by Electromobility Shift Assay (EMSA). Co-culture of BCBL-1 cells with ionophore-stimulated primary neutrophils lead to an increased production of LTB4 by transcellular biosynthesis compared to L-428 cells, demonstrating the functional significance of LTA4H upregulation. BCBL-1 cells also demonstrated increased migration even in the absence of chemotactic stimulus compared to L-428 cells. These observations indicate that (1) disruption of the B-cell specific transcriptional program is likely to contribute to the incomplete B cell phenotype characteristic of PEL cells and (2) upregulation of factors involved in cell migration and chemotaxis constitute a unique characteristic of PEL cells that may contribute to the localization of this lymphoma to serous body cavities.
40
Keller, Michael [Verfasser]. "Numerical Investigation of Gaseous Film and Effusion Cooling in Supersonic Boundary-Layer Flows / Michael Keller". München : Verlag Dr. Hut, 2016. http://d-nb.info/1111160759/34.
Pełny tekst źródła
41
Ghadiani, Saeed Reza. "A multiphasic continuum mechanical model for design investigations of an effusion-cooled rocket thrust chamber". Köln : Deutsches Zentrum für Luft- und Raumfahrt e. V, 2005. http://www.gbv.de/dms/goettingen/508838495.pdf.
Pełny tekst źródła
42
Hartley, Douglas E. H. "Effects of conductive hearing loss on auditory temporal resolution". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365822.
Pełny tekst źródła
43
Freitas, Sergio Luiz Oliveira de. "Toracoscopia em crianças com derrame parapneumônico complicado na fase fibrinopurulenta". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/11504.
Pełny tekst źródłaStreszczenie:
Introdução: Apesar de a toracoscopia ser o procedimento preconizado em crianças com derrame pleural parapneumônico complicado (DPPC) na fase fibrinopurulenta, a grande maioria dos trabalhos citados na literatura é de relato de casos ou revisão de pequeno número de pacientes. Este estudo interinstitucional foi realizado para determinar a eficácia deste procedimento em número significativo de crianças com DPPC na fase fibrinopurulenta. Métodos: Estudo retrospectivo de 99 crianças (0,4 a 11 anos; idade média 2,6 anos) submetidas à toracoscopia para tratamento de DPPC na fase fibrinopurulenta, operadas em três hospitais diferentes e com mesmo algoritmo de tratamento, no período de novembro de 1995 a julho de 2005. Resultados: A toracoscopia foi eficaz em 87 crianças (87%); 12 (13%) necessitaram de outro procedimento cirúrgico - 6 novas toracoscopias e 6 toracotomia/pleurostomia. O tempo médio de drenagem após a toracoscopia foi de 3 dias naqueles em que a toracoscopia foi efetiva e de 10 dias nos reintervidos (P < 0,001). Todos resolveram a infecção pleural. As complicações da toracoscopia foram enfisema subcutâneo na inserção do trocater em duas crianças (2%), infecção da ferida operatória em outras duas (2%), sangramento pelo dreno torácico em 12 (12%) e fístula bronco pleural em 16 (16%). Nenhuma necessitou intervenção cirúrgica, Conclusões: A efetividade da toracoscopia em crianças com DPPC na fase fibrinopurulenta foi de 87%. O procedimento mostrou-se seguro, com baixa incidência de complicações graves, devendo ser considerada como primeira opção em crianças com DPPC na fase fibrinopurulenta.Introduction: Although Thorachoscopy being a procedure used to treat children with complicated parapneumonic pleural effusion (DPPC) in fibrinopurulent stage, most of the works presented in literature are case reports of only a few patients. The purpose of this work is to carry on a cross institutional study to determine the method’s effectiveness on a significant number of children with DPPC in its purulent stage. Methods: This is a retrospective case study of 99 children (ages 0,4 to 11; average age 2,6), from November 1009 to July 2005, submitted to thorachoscopy for the treatment of DPPC in fibrinopurulent stage, operated in three different hospitals and with the same treatment algorithm. Results: Thorachoscopy was effective for 87 children (87%). 12 (12%) needed to be submitted to another surgery – 6 to another thorachoscopy and 6 to thorachotomy/pleurostomy. The average draining time after thorachoscopy was 3 days for those whose thorachoscopy was effective and 10 days for those who were submitted to a new surgery (P< 0,001). In all cases, the pleural infection was successfully treated. Complications of the thorachoscopy were subcutaneous emphysema in the trocater insertion on two patients (2%), infection of the surgery incision on two other patients, bleeding through drain on 12 patients (12%) and bronchialpleural fistula on 16 patients (16%). None of them needed surgical treatment. Conclusion: The effectiveness of thorachoscopy on children with DPPC in fibrinopurulent stage was 87%. The procedure had low incidence of serious complications, and should be considered the first treatment option for children with DPPC in fibrinopurulent stage.
44
Joinet, Angélique. "Production de faisceaux d'ions radioactifs chimiquement réactifs par séparation en ligne". Paris 11, 2003. http://www.theses.fr/2003PA112163.
Pełny tekst źródłaStreszczenie:
La méthode de séparation d'isotope en ligne (ISOL), permet de produire par réaction de spallation, de fragmentation ou de fission des faisceaux d'ions radioactifs plus ou moins loin de la vallée de la stabilité. Bombardée par un faisceau primaire de forte intensité, la cible de production est épaisse, ce qui permet d'obtenir de forte production. Le problème est de trouver des matériaux de cible qui à haute température, relâchent rapidement les produits de réactions arrêtés dans la cible. Cette méthode radiochimique, optimisée pour fonctionner avec une source d'ions utilise les propriétés thermochimiques comme la pression de vapeur, la diffusion et la désorption. Le délai dû au transfert de masse limite l'efficacité de production et en particulier celle des isotopes de courte durée de vie. Pour les éléments des groupes chimiques 14 et 16 qui sont chimiquement réactifs vis-à-vis de leur environnement de production, cette technique a été inefficace. L'introduction du processus d'évaporation chimique apporte une solution. Cette technique, au cours de laquelle un agent chimique est introduit dans la cible, assure le transport de l'élément en question vers la source d'ions, sous forme de molécules. Les faisceaux d'ions radioactifs de sélénium et de soufre déficients en neutrons ainsi que les faisceaux d'étain riches en neutrons sont de grands intérêts pour la communauté des physiciens. L'objectif de nos travaux a été d'optimiser l'ensemble cible source, afin d'obtenir des faisceaux d'ions radioactifs ayant une intensité et une pureté exploitable. Tout d'abord, des mesures hors ligne ont permis de trouver des matériaux de cible adaptés au relâchement de ces isotopes et de plusieurs autres éléments. Ensuite, des mesures en ligne ont permis d'étudier la formation, la stabilité et l'ionisation des molécules COSe, COS, SnS et GeS. Un des grands avantages de la méthode d'évaporation chimique est d'obtenir des molécules volatiles et de réduire la contamination isobarique. Les travaux de cette thèse qui s'inscrivent dans le cadre du projet EURISOL, visant à construire une nouvelle génération d'accélérateur qui délivrerait des faisceaux de fortes intensités et d'une grande pureté, ont démontré qu'un traitement physico chimique des isotopes dans leur environnent est crucialThe isotope separation on line method allows to produce by spallation, fragmentation or fission reaction, radioactive ion beams far from the valley of stability. A thick target is irradiated by a high intensity primary beam. Therefore, high production can be achieved. The problem is to find target material that releases rapidly at high temperature, the reaction products stopped into the target. This radiochemical method, optimised to work with an ion source, is based on the thermochemical properties as vapour pressure, diffusion and desorption. The delay due to the mass transfer will have some consequences on the production efficiency, and particularly for the short half life isotopes. This technique has been inefficient for the 14 and 16 group elements, which are chemically reactive in their production environment. The introduction of the chemical evaporation can solve the problem. Chemical specie is introduced into the target, allowing the transportation of the element as a molecule towards the ion source. The neutron deficient selenium and sulphur radioactive ion beams and the neutron rich tin beams are of great interest for the physicist community. The goal of my work has been to optimise the target and ion source unit in order to achieve high intensity and purity. First, off line measurements allowed to find target material dealing to a fast release of these isotopes and of several elements. Afterwards, we studied the formation, stability and ionisation of the COSe, COS, SnS and GeS molecules by on line measurements. One advantage of the chemical evaporation method is to obtaine volatile molecules and to reduce isobaric contamination. This thesis has been done in the frame of the EURISOL project. This would construct a new generation accelerator, that would deliver high intensity and high purity ion beams. And this work demonstrates that a chemical physical treatment of isotopes in their environment is crucial
45
Kincal, Serkan. "Modeling and control of multiple thermal effusion sources and substrate temperature in molecular beam epitaxy reactors". [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE1000135.
Pełny tekst źródła
46
Daniel, Matija. "Otitis media with effusion : current treatment, new understanding of its aetiopathogenesis, and a novel therapeutic approach". Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/28069/.
Pełny tekst źródłaStreszczenie:
Otitis Media with Effusion (OME) is a common childhood condition leading to hearing loss, and its treatment with ventilation tubes (VTs) is one of the commonest surgical procedures. However, aetiology of OME is poorly understood, and its current treatment requires improvement as OME frequently recurs once VTs extrude. The first, clinical part of this thesis showed that 63.6% of children randomised to VT insertion in a clinical trial will require VTs again, and even with additional adenoidectomy the need for repeat surgery remains high. Although published national guidelines set out criteria for surgery, the multicentre study presented here showed that only 32.2% of children that had VTs met these criteria, and guidelines' publication had limited impact on clinical practice. The second, laboratory part of this thesis demonstrated the importance that bacteria and biofilms play in aetiology of OME, as live bacteria were demonstrated in 91.9% of middle ear effusions (using culture and confocal microscopy). Following from this, a Staphylococcus aureus biofilm model was developed, and used to show that biofilm eradication requires antibiotic (rifampicin and lindamycin) levels 1,000 times higher than those required to inhibit planktonic bacteria, over a period of 2-3 weeks. To achieve this in the middle ear, a local delivery strategy using biodegradable poly (Iactic-coglycolic acid) antibiotic pellets was proposed. Drug release from these pellets was investigated with High Performance Liquid Chromatography and Serial Plate Transfer Testing, which demonstrated that antibiotics can be released for up to 3 weeks. Importantly, the pellets were able to eradicate biofilms in the in vitro model. This thesis has shown that current OME treatment has significant deficiencies, but better understanding of OME pathogenesis raises the possibility of rational new therapeutic strategies. Biodegradable antibiotic pellets designed to eradicate OME biofilms may be a better future treatment that could improve the lives of countless children.
47
Casey, Maria Paula. "The Relationship Between 6/9 Distance Vision, Otitis Media with Effusion and Emergent Letter Name Knowledge". Thesis, University of Canterbury. Health Sciences, 2013. http://hdl.handle.net/10092/9062.
Pełny tekst źródłaStreszczenie:
Background: There is a need for more well-controlled research on the relationship between
vision and hearing limitations and emergent literacy to inform early literacy intervention.
Two highly prevalent difficulties of early childhood, poor distance visual acuity and otitis
media with effusion (OME), have been shown to be associated with literacy achievement.
There is little research, however, on the relationship between these conditions and emergent
literacy.
Objective: The objective of this study was to assess the relationships between (1) distance
visual acuity and emergent letter name knowledge, and (2) OME status and emergent letter
name knowledge in children at school entry.
Method: A prospective cohort of children (N=298) was recruited at school entry. Participants
were aged 5, did not require special education for high needs and spoke a nationally
recognized language of New Zealand. Distance vision and tympanometry testing was
performed and a parent report of OME was obtained. The Wechsler Individual Test of Letter
Name Knowledge and the Vocabulary and Block Design sub-tests of the Wechsler
Intelligence Scale for Children were administered. Covariates of reading achievement were
also measured.
Results: Twenty three percent of children knew fewer than 4 letters at school entry, 31.9%
had marginal distance visual acuity of 6/9 in one or both eyes and 37.2% had a history of ear
infections and/or a B tympanometry test at school entry. Logistic regression tests
demonstrated that both 6/9 vision (OR= 2.069, CI0.95=0.999-4.227) and OME status
10
(OR=1.846, CI0.95=1.034-3.297) were significantly associated with low letter name
knowledge at school entry, controlling for covariates of emergent literacy. Another analysis
showed that children with 6/9 vision and/or OME at school entry were also at greater risk for
low letter knowledge (OR=2.187, CI0.95=1.067 – 4.484) than children with 6/6 vision and no
OME at school entry.
Conclusions: The results of the current study indicate that 6/9 distance vision and OME
are risk factors for low letter name knowledge at school entry. These factors warrant
greater consideration with regard to early literacy intervention, classroom teaching
practices and future research.
48
Smith, Sarah C. "Measurement of quality of life, behaviour and health outcomes in children with otitis media and effusion". Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266939.
Pełny tekst źródła
49
Solari, Lely, Alonso Soto i der Stuyft Patrick Van. "Development of a clinical prediction rule for the diagnosis of pleural tuberculosis in Peru". Elsevier B.V, 2018. http://hdl.handle.net/10757/623065.
Pełny tekst źródłaStreszczenie:
Objectives: To develop a clinical prediction rule (CPR) for the diagnosis of pleural tuberculosis (PT) in patients with pleural exudates in Peru. Methods: Clinical and laboratory information was collected from patients with exudative pleural effusion attending two reference hospitals in Lima, Peru. Predictive findings associated with PT in a multiple logistic regression model were used to develop the CPR. A definite diagnosis of PT was based on a composite reference standard including bacteriological and/or histological analysis of pleural fluid and pleural biopsy specimens. Results: A total of 238 patients were included in the analysis, of whom 176 had PT. Age, sex, previous contact with a TB patient, presence of lymphadenopathy, and pleural adenosine deaminase (ADA) levels were found to be independently associated with PT. These predictive findings were used to construct a CPR, for which the area under the receiver operating characteristics curve (AUC) was 0.92. The single best cut-off point was a score of ≥60 points, which had a sensitivity of 88%, specificity of 92%, a positive likelihood ratio of 10.9, and a negative likelihood ratio of 0.13. Conclusions: The CPR is accurate for the diagnosis of PT and could be useful for treatment initiation while avoiding pleural biopsy. A prospective evaluation is needed before its implementation in different settings.
50
Maartens, Gary. "Tuberculous pleural effusions : a prospective study of rapid diagnostic tests (adenosine deaminase, antigen capture enzyme-linked immunosorbent assay, and the polymerase chain reaction) and evaluation of a radiometric mycobacterial culture system". Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/26240.
Pełny tekst źródłaStreszczenie:
A prospective study was undertaken to assess the diagnostic value of various rapid diagnostic tests for tuberculosis in pleural fluid, and to assess the sensitivity and speed of a radiometric mycobacterial culture system (BACTEC, Johnson Laboratories). Patients presenting to the Department of Medicine at Groote Schuur Hospital with pleural effusions for diagnostic pleural aspiration and biopsy over a 6 month period were entered into the study. Because the incidence of tuberculous effusions was observed to be high in this population (65% of 94 patients), patients from the Department of Radiotherapy with proven malignant disease and the development of new pleural effusions requiring diagnostic or therapeutic aspiration were included in the study in order to increase the number of control patients without tuberculosis. The 111 patients (17 of whom were recruited from the Department of Radiotherapy) were divided into 4 diagnostic categories: tuberculosis - 62 patients, malignant - 28 patients, miscellaneous conditions - 10 patients, and undiagnosed - 11 patients (3 of whom probably had tuberculosis). There were 59 male patients. The racial distribution was 11 whites, 51 of mixed race, and 49 blacks. Exudative pleural effusions were present in 109 patients. Closed pleural biopsies with the Abrams needle were performed on 100 patients using a modified version of the standard technique whereby larger specimens were obtained by stripping pleura off the chest wall. Seven pleural biopsies were reported as inadequate by the pathologist and the diagnostic yield of the procedure was 63%. Tuberculosis was confirmed histologically or by culture in 62 patients. The age distribution of these patients was bimodal, with most cases occuring in the third decade. The presentation was usually acute, with 60% of patients being symptomatic for less than 4 weeks. Granulomata were found on initial pleural biopsy in 52 cases (84%). Pleural biopsy culture was positive in 44 cases (71%). The radiometric culture system tested (12B BACTEC) yielded the same number (14) of positive cultures as conventional mycobacterial culture media in pleural fluid, but was almost twice as fast. Bedside inoculation of pleural fluid into 13A BACTEC bottles more than doubled the yield in the 24 patients tested (11 positive cultures compared with 4 each for conventional and 12B BACTEC media, p=0.046). The rapid diagnostic tests assessed on pleural fluid were adenosine deaminase (ADA), an antigen (BCG) capture enzymelinked immunosorbent assay (ELISA), and a specific DNA probe after amplification with the polymerase chain reaction. ADA was found to have a sensitivity of 0.77 and a specificity of 0.83 in the 109 patients tested, and values were significantly higher in tuberculosis patients compared with the other three diagnostic categories (p< 0.001 ). The ELISA test was performed on 103 patients and showed a sensitivity of only 0.26 and a specificity of 0.72. The DNA probe was performed on 43 patients, and had a sensitivity of 0.93 with a specificity of 0.43. Contamination of samples or latent tuberculous infection may have been responsible for the poor specificity of the DNA probe.