Relevant bibliographies by topics / Viscoelastic respiratory system properties

Academic literature on the topic 'Viscoelastic respiratory system properties'

Author: Grafiati
Published: 11 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Viscoelastic respiratory system properties.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Viscoelastic respiratory system properties"

1

Jonson, B., L. Beydon, K. Brauer, C. Mansson, S. Valind, and H. Grytzell. "Mechanics of respiratory system in healthy anesthetized humans with emphasis on viscoelastic properties." Journal of Applied Physiology 75, no. 1 (July 1, 1993): 132–40. http://dx.doi.org/10.1152/jappl.1993.75.1.132.

Full text
Abstract:
The classic model of the respiratory system (RS) is comprised of a Newtonian resistor in series with a capacitor and a viscoelastic unit including a resistor and a capacitor. The flow interruption technique has often been used to study the viscoelastic behavior under constant inspiratory flow rate. To study the viscoelastic behavior of the RS during complete respiratory cycles and to quantify viscoelastic resistance (Rve) and compliance (Cve) under unrestrained conditions, we developed an iterative technique based on a differential equation. We, as others, assumed Rve and Cve to be constant, which concords with volume and flow dependency of model behavior. During inspiration Newtonian resistance (R) was independent of flow and volume. During expiration R increased. Static elastic recoil showed no significant hysteresis. The viscoelastic behavior of the RS was in accordance with the model. The magnitude of Rve was 3.7 +/- 0.7 cmH2O.l-1 x s, i.e., two times R. Cve was 0.23 +/- 0.051 l/cmH2O, i.e., four times static compliance. The viscoelastic time constant, i.e., Cve.Rve, was 0.82 +/- 0.11s. The work dissipated against the viscoelastic system was 0.62 +/- 0.13 cmH2O x 1 for a breath of 0.56 liter, corresponding to 32% of the total energy loss within the RS. Viscoelastic recoil contributed as a driving force during the initial part of expiration.
APA, Harvard, Vancouver, ISO, and other styles
2

Antonaglia, V., A. Grop, P. Demanins, F. Beltrame, U. Lucangelo, A. Peratoner, L. De Simoni, A. Gullo, and J. Milic-Emili. "Single-breath method for assessing the viscoelastic properties of the respiratory system." European Respiratory Journal 12, no. 5 (November 1, 1998): 1191–96. http://dx.doi.org/10.1183/09031936.98.12051191.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Similowski, T., and JH Bates. "Two-compartment modelling of respiratory system mechanics at low frequencies: gas redistribution or tissue rheology?" European Respiratory Journal 4, no. 3 (March 1, 1991): 353–58. http://dx.doi.org/10.1183/09031936.93.04030353.

Full text
Abstract:
The mechanical properties of the respiratory system are generally inferred from measurements of pressure and flow at the airway opening. Traditionally, these measurements have been related through a single-compartment model of the respiratory system. Recently, however, there has been considerable interest in modelling low-frequency respiratory mechanics in terms of two compartments, since this gives a much improved description of experimental data. In this paper we consider two classes of two-compartment models that are compatible with pressure-flow relationships of air measured at the airway opening. One type of model accounts for regional ventilation inhomogeneity in the lung in terms of two alveolar compartments. The other type of model considers pulmonary ventilation to be homogeneous, while the tissues of the respiratory system are modelled as being viscoelastic. In normal dogs, the appropriate two-compartment model has been shown to be the viscoelastic model. In the case of abnormal physiology, however, one must invoke a model having both viscoelastic tissues and ventilation inhomogeneities. Additional experimental data are required in order to identify such a model, and to quantify these two phenomena.
APA, Harvard, Vancouver, ISO, and other styles
4

Bates, J. H. T., and J. Milic-Emili. "Influence of the viscoelastic properties of the respiratory system on the energetically optimum breathing frequency." Annals of Biomedical Engineering 21, no. 5 (September 1993): 489–99. http://dx.doi.org/10.1007/bf02584331.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Clement, M. G., and M. Dimori. "Inhaled Nitric Oxide Counterbalances ET-1 Dependent Pulmonary Hypertension and Bronchoconstriction in the Pig." Mediators of Inflammation 3, no. 2 (1994): 131–35. http://dx.doi.org/10.1155/s0962935194000165.

Full text
Abstract:
In anaesthetized, paralysed, ventilated pigs the ability of inhaled nitric oxide (80 ppm in 02) to reduce the haemodynamic and respiratory effects of endothelin-1 administration (200 pmol/kg, i.v.) was evaluated. The mechanical properties of the respiratory system were evaluated by the rapid airway occlusion technique. The overall respiratory resistance, the interrupter resistance and the additional resistance that reflects the viscoelastic properties of tissues and the inequality of the time constant within the system were also evaluated. The results show that inhaled nitric oxide can act as a selective pulmonary vasodilator and as a bronchodilator to counteract the vasoconstrictor and bronchoconstrictor activity of endothelin-1. In the pig, nitric oxide inhaled at 80 ppm for 6 mitt reduced the changes in respiratory-, interrupter- and additional resistance due to endothelin-1 administration without significantly changing the static and dynamic elastance of the respiratory system.
APA, Harvard, Vancouver, ISO, and other styles
6

Correa, Fatima C. F., Patricia B. Ciminelli, Haroldo Falcão, Bruno J. C. Alcântara, Renata S. Contador, Aline S. Medeiros, Walter A. Zin, and Patricia R. M. Rocco. "Respiratory mechanics and lung histology in normal rats anesthetized with sevoflurane." Journal of Applied Physiology 91, no. 2 (August 1, 2001): 803–10. http://dx.doi.org/10.1152/jappl.2001.91.2.803.

Full text
Abstract:
Respiratory system, lung, and chest wall mechanical properties were subdivided into their resistive, elastic, and viscoelastic/inhomogeneous components in normal rats, to define the sites of action of sevoflurane. In addition, we aimed to determine the extent to which pretreatment with atropine modified these parameters. Twenty-four rats were divided into four groups of six animals each: in the P group, rats were sedated (diazepam) and anesthetized with pentobarbital sodium; in the S group, sevoflurane was administered; in the AP and AS groups, atropine was injected 20 min before sedation/anesthesia with pentobarbital and sevoflurane, respectively. Sevoflurane increased lung viscoelastic/inhomogeneous pressures and static elastance compared with rats belonging to the P group. In AS rats, lung static elastance increased in relation to the AP group. In conclusion, sevoflurane anesthesia acted not at the airway level but at the lung periphery, stiffening lung tissues and increasing mechanical inhomogeneities. These findings were supported by the histological demonstration of increased areas of alveolar collapse and hyperinflation. The pretreatment with atropine reduced central and peripheral airway secretion, thus lessening lung inhomogeneities.
APA, Harvard, Vancouver, ISO, and other styles
7

D’Angelo, Edgardo, Edoardo Calderini, Mario Tavola, and Matteo Pecchiari. "Standard and viscoelastic mechanical properties of respiratory system compartments in dogs: Effect of volume, posture, and shape." Respiratory Physiology & Neurobiology 261 (March 2019): 31–39. http://dx.doi.org/10.1016/j.resp.2018.12.003.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Freezer, N. J., C. J. Lanteri, and P. D. Sly. "Effect of pulmonary blood flow on measurements of respiratory mechanics using the interrupter technique." Journal of Applied Physiology 74, no. 3 (March 1, 1993): 1083–88. http://dx.doi.org/10.1152/jappl.1993.74.3.1083.

Full text
Abstract:
The relationship between respiratory mechanics, changes in pulmonary blood flow (PBF), pulmonary arterial pressure, and left atrial pressure is unclear. Conventional methods for the measurement of respiratory mechanics model the respiratory system as a single compartment, which may not adequately represent the respiratory system in a diseased state. The interrupter technique models the respiratory system as two compartments, with the "flow resistance" of the conducting airways and chest wall (Raw) considered separately from Pdif, a measure of the viscoelastic properties of the lung and chest wall, together with any pendelluft present. The respiratory mechanics of 15 infants in the first year of life were studied during cardiac catheterization with the use of conventional methods and the interrupter technique. The infants had a PBF-to-systemic blood flow ratio ranging from 0.6 to 4.0:1. The specific dynamic compliance of the respiratory system was not related to the PBF; however, there was a significant relationship between PBF and the total resistance of the respiratory system (Rrs) [analysis of variance (ANOVA) F = 5.69, P < 0.05], Raw (ANOVA, F = 12.30, P < 0.01), and Pdif (ANOVA, F = 3.79, P < 0.05). Rrs increased significantly with an increase in mean left atrial pressure (ANOVA, F = 6.92, P < 0.05); however, dynamic compliance, Raw, and Pdif did not. These results suggest that the relationship between Rrs and PBF is due an increase in the resistive properties of the conducting airways and tissue components.
APA, Harvard, Vancouver, ISO, and other styles
9

Pelosi, P., M. Croci, I. Ravagnan, M. Cerisara, P. Vicardi, A. Lissoni, and L. Gattinoni. "Respiratory system mechanics in sedated, paralyzed, morbidly obese patients." Journal of Applied Physiology 82, no. 3 (March 1, 1997): 811–18. http://dx.doi.org/10.1152/jappl.1997.82.3.811.

Full text
Abstract:
Pelosi, P., M. Croci, I. Ravagnan, M. Cerisara, P. Vicardi, A. Lissoni, and L. Gattinoni. Respiratory system mechanics in sedated, paralyzed, morbidly obese patients J. Appl. Physiol. 82(3): 811–818, 1997.—The effects of inspiratory flow and inflation volume on the mechanical properties of the respiratory system in eight sedated and paralyzed postoperative morbidly obese patients (aged 37.6 ± 11.8 yr who had never smoked and had normal preoperative seated spirometry) were investigated by using the technique of rapid airway occlusion during constant-flow inflation. With the patients in the supine position, we measured the interrupter resistance (Rint,rs), which in humans probably reflects airway resistance, the “additional” resistance (ΔRrs) due to viscoelastic pressure dissipation and time-constant inequalities, and static respiratory elastance (Est,rs). Intra-abdominal pressure (IAP) was measured by using a bladder catheter, and functional residual capacity was measured by the helium-dilution technique. The results were compared with a previous study on 16 normal anesthetized paralyzed humans. Compared with normal persons, we found that in obese subjects: 1) functional residual capacity was markedly lower (0.645 ± 0.208 liter) and IAP was higher (24 ± 2.2 cmH2O); 2) alveolar-arterial oxygenation gradient was increased (178 ± 59 mmHg); 3) the volume-pressure curve of the respiratory system was curvilinear with an “inflection” point; 4) Est,rs, Rint,rs, and ΔRrs were higher than normal (29.3 ± 5.04 cmH2O/l, 5.9 ± 2.4 cmH2O ⋅ l−1 ⋅ s, and 6.4 ± 1.6 cmH2O ⋅ l−1 ⋅ s, respectively); 5) Rint,rs increased with increasing inspiratory flow, Est,rs did not change, and ΔRrs decreased progressively; and 6) with increasing inflation volume, Rint,rs and Est,rs decreased, whereas ΔRrs rose progressively. Overall, our data suggest that obese subjects during sedation and paralysis are characterized by hypoxemia and marked alterations of the mechanical properties of the respiratory system, largely explained by a reduction in lung volume due to the excessive unopposed IAP.
APA, Harvard, Vancouver, ISO, and other styles
10

Bates, J. H., K. A. Brown, and T. Kochi. "Respiratory mechanics in the normal dog determined by expiratory flow interruption." Journal of Applied Physiology 67, no. 6 (December 1, 1989): 2276–85. http://dx.doi.org/10.1152/jappl.1989.67.6.2276.

Full text
Abstract:
We recently proposed an eight-parameter model of the respiratory system to account for its mechanical behavior when flow is interrupted during passive expiration. The model consists of two four-parameter submodels representing the lungs and the chest wall, respectively. The lung submodel consists of an airways resistance together with elements embodying the viscoelastic properties of the lung tissues. The chest wall submodel has similar structure. We estimated the parameters of the model from data obtained in four normal, anesthetized, paralyzed, tracheostomized mongrel dogs. This model explains why lung tissue and chest wall resistances should be markedly frequency dependent at low frequencies and also permits a physiological interpretation of resistance measurements provided by the flow interruption method.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Viscoelastic respiratory system properties"

1

Lucangelo, Umberto. "Titration of High Frequency Percussive Ventilation by means of real-time monitoring of the viscoelastic respiratory system properties and endotracheal tubes pressure drop." Doctoral thesis, Università degli studi di Trieste, 2014. http://hdl.handle.net/10077/9992.

Full text
Abstract:
2012/2013
The use of High Frequency Percussive Ventilation (HFPV) is still debated although this type of non-conventional ventilation has proven effective and safe in patients with acute respiratory failure. In the clinical practice, HFPV is not an intuitive ventilatory modality and the absence of real-time delivered volume monitoring produces disaffection among the physicians. Avoiding the "volutrauma" is the cornerstone of the "protective ventilation strategy", which assumes a constant monitoring of inspiratory volume delivered to the patient. Currently the system capable of delivering HFPV is the VDR-4® (Volumetric Diffusive Respirator), which provides only analog airway pressure waveform and digital output of peak and the mean airway pressure. The latter is involved in the determination of oxygenation and hemodynamics, irrespective of the mode of ventilation. At the present time, the mean airway pressure, together with gas exchange analysis, are the only parameters that indirectly guide the physician in assessing the clinical effectiveness of HFPV. Till now, flow, volume and pressure curves generated by HFPV have never been studied in relation to the specific patients respiratory mechanics. The real-time examination of these parameters could allow the physicians to analyze and understand elements of respiratory system mechanics as compliance (Crs), resistance (Rrs), inertance (Irs) and of patient-ventilator interaction. The mechanical effects are complex and result from interactions between ventilator settings and patient’s respiratory system impedance. The aim of this doctoral thesis was to acquire and study volume and respiratory parameters during HFPV in order to explain this complex patients-machine interaction and transfer the results in clinical practice.
XXVI Ciclo
1959
APA, Harvard, Vancouver, ISO, and other styles
2

Ajčević, Miloš. "Personalized setup of high frequency percussive ventilator by estimation of respiratory system viscoelastic parameters." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10976.

Full text
Abstract:
2013/2014
High Frequency Percussive Ventilation (HFPV) is a non-conventional ventilatory modality which has proven highly effective in patients with severe gas exchange impairment. However, at the present time, HFPV ventilator provides only airway pressure measurement. The airway pressure measurements and gas exchange analysis are currently the only parameters that guide the physician during the HFPV ventilator setup and treatment monitoring. The evaluation of respiratory system resistance and compliance parameters in patients undergoing mechanical ventilation is used for lung dysfunctions detection, ventilation setup and treatment effect evaluation. Furthermore, the pressure measured by ventilator represents the sum of the endotracheal tube pressure drop and the tracheal pressure. From the clinical point of view, it is very important to take into account the real amount of pressure dissipated by endotracheal tube to avoid lung injury. HFPV is pressure controlled logic ventilation, thus hypoventilation and hyperventilation cases are possible because of tidal volume variations in function of pulmonary and endotracheal tube impedance. This thesis offers a new approach for HFPV ventilator setup in accordance with protective ventilatory strategy and optimization of alveolar recruitment using estimation of the respiratory mechanics parameters and endotracheal pressure drop. Respiratory system resistance and compliance parameters were estimated, firstly in vitro and successively in patients undergoing HFPV, applying least squares regression on Dorkin high frequency model starting from measured respiratory signals. The Blasius model was identified as the most adequate to estimate pressure drop across the endotracheal tube during HFPV. Beside measurement device was developed in order to measure respiratory parameters in patients undergoing HFPV. The possibility to tailor HFPV ventilator setup, using respiratory signals measurement and estimation of respiratory system resistance, compliance and endotracheal tube pressure drop, provided by this thesis, opens a new prospective to this particular ventilatory strategy, improving its beneficial effects and minimizing ventilator-induced lung damage.
XXVII Ciclo
1981
APA, Harvard, Vancouver, ISO, and other styles
3

Hsieh, Chia-wen Carmen. "Effect of molecular structure on the viscoelastic properties of cellulose acetate in a ternary system." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30515.

Full text
Abstract:
A series of ternary systems composed of cellulose acetate (CA), N,N-dimethylacetamide (DMA), and water were prepared by varying the mixing temperature, order of component addition, and polymer substitution pattern with increasing water content. The viscoelastic properties of the resulting ternary systems were measured using steady state and dynamic rheology. The CA/DMA/H₂O mixture formed physical gels at 17.5 and 19 wt% nonsolvent concentrations after heating to 50 and 70/90°C respectively. Gel formation was characterized by the loss of a Newtonian plateau in the steady state as well as the transition of the elastic (G') modulus becoming greater than the viscous (G") modulus in the dynamic state. The molecular structure of the polymer influenced the viscoelastic properties of the resulting gel. Commercially available CA was found to be partially acetylated at the C2, C3, and C6 positions and contained a total degree of substitution (DS) of 2.47. As CA cluster size in solution decreases with increasing temperature, viscosity measurements showed higher viscosity for samples heated at 50°C, where the loss of the linear stress-strain relationship occurred at 17.5 wt% water. In the dynamic state, higher heating temperature produced higher elastic moduli with a longer linear viscoelastic region (LVR), indicative of a stable system. Changing the sequence of polymer addition by adding CA to a DMA/H₂O solution resulted in lower overall viscoelastic moduli as compared to adding water to a CA/DMA solution. CA that was regioselectively synthesized to a DS of 2.4 showed different viscoelastic behaviour than the commercial CA. This polymer was completely acetylated at C2 and C3 and partially acetylated at position 6. The system underwent phase separation induced gelation at much lower nonsolvent content. Stress sweep experiments confirmed a shorter LVR and higher G' than commercial CA. Increasing the DS of the regioselective polymer to 2.8 led to a longer LVR and higher G' than all other polymers at the same nonsolvent content. The enhanced steady shear viscosity and dynamic viscoelastic properties were a result of the intensification of hydrogen bonding and hydrophobic interactions between the polymer, solvent, and nonsolvent.
APA, Harvard, Vancouver, ISO, and other styles
4

Fan, Yi, and 樊怡. "The applications of computational fluid dynamics to the cardiovascularsystem and the respiratory system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47753195.

Full text
Abstract:
The diseases of cardiovascular system and the respiratory system have been the second and third killers causing deaths in Hong Kong. In this stressful civilized world, the prevalence and incidence of these diseases increased prominently which arouse our concern on the theories behind the pathological conditions. This report will focus on the biofluid mechanics in the large artery and in the upper airway. Thoracic aortic dissection, characterized by the tearing in the middle layer of vessel wall, is a catastrophic vascular disorder. The wall of the newly formed channel, the false lumen, is weakened and prone to aortic events. Endovascular repair is a minimally invasive technique for treating dissection patients. The biomechanical factors and the length of endograft were studied by computational fluid dynamics. Two geometrical factors showed a significant impact on the backflow in the false lumen. A larger false lumen and a larger distal tear size greatly affected the extent of thrombosis in the false lumen. It made the false lumen under a higher risk of vessel rupture. The computational prediction also demonstrated a more stable hemodynamic condition in the model with a longer endograft. These results provide important information for the clinicians to propose the surgical procedures and to improve the design of endografts. Airway obstruction is a common breathing disorder but it is always underdiagnosed. Obstructive sleep apnea (OSA) and different dentofacial deformities are two pathological conditions in which the patients have the abnormal sizes of airways. Computational fluid dynamic was employed in both conditions with patient–specific models. In the part of OSA, pre– and post–operative models were studied. The dimensions and flow resistance of the upper airway showed a significant improvement after mandibular distraction. The percentage of stenosis and the flow resistance was reduced by 27.3% and 40.7% respectively. For the patients in three facial skeletal deformity groups, the cross–sectional area and the flow resistance were compared. The patients with Class II deformity had the smallest retroglossal and retroplatal dimensions as well as the greatest flow resistance. The results confirmed the effectiveness of mandibular distraction and also provide valuable implications for the clinicians on the treatment planning, particularly for the Class II subjects.
published_or_final_version
Mechanical Engineering
Master
Master of Philosophy
APA, Harvard, Vancouver, ISO, and other styles
5

Korehei, Reza. "Effect of non-solvent on viscoelastic and microstructural properties of cellulose acetate in a ternary system." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/32881.

Full text
Abstract:
In this study, the effects of component composition on rheological and microstructural behaviour of a ternary of cellulose acetate (CA), N,N-dimethylacetamide (DMAc) and non-solvent (1-Propanol, 2-Propanol, 1-Hexanol, 1-Octanol, 1-Decanol, 1,2-Ethanediol, 1,2-Propanediol, 1,3-Propanediol, 1,4-Butanediol, 1,6-Hexanediol, Glycerol) system was examined. In this ternary system, physical gel formation can arise as a result of phase separation, which is characterized by the observation of a gradual to extreme cloudiness in the system. Depending on the non-solvent concentration, structure and polymer concentration, phase separation leads to CA aggregation and the formation of large macromolecular assemblies. Sol-gel transition is observed at a critical non-solvent concentration, which is dependent on the non-solvent structure and CA concentration. Increasing CA and non-solvent concentration resulted in enhanced steady shear viscosity and dynamic viscoelastic properties. Enhanced dynamic viscoelastic property and gelation are due to the intensification of intermolecular hydrogen bonding and hydrophobic interactions. Increasing the available hydrogen-bonding groups within the non-solvent leads to the formation of gels with larger elastic and viscous modulus (G' and G"), and a lower concentration sol-gel transition. Likewise, increasing the hydrophobic component of the non-solvent also enhanced the gel properties and accelerated the sol-gel transition. Although hydrophobic interactions play a role in the gelation process, it appears that gel properties are greatly influenced by competitive hydrogen bonding between system components. Competitive hydrogen bonding interactions between components in the various stages of the phase separation and gel formation was used to explain the weak and strong polymer-network structures observed by rheology. Through the use of Fourier transfer infrared (FTIR) spectroscopy the effect of hydrogen bonding between CA, DMAc and non-solvent were probed. Shifting the hydroxyl (OH) band to a lower wavenumber in the FTIR spectra suggests the intensification of the intermolecular hydrogen bonds in the ternary system. This shift accounts for the phase separation, and development of microstructure in the sample. Increasing the non-solvent content shifts the yield strain of the gels to a lower strain value, suggesting that they are made of floes. These floes consist of aggregated macromolecules with strong-links, and the links between floes are stronger than the links within the floes. The power-law dependence of elastic modulus (G1), together with similar values of fractal dimension for gels observed through confocal microscopy, suggests that the gels are fractal in nature and that they are made through an aggregation mechanism. Scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) revealed differences in the gel microstructure, depending on the constituent composition. Microscopic images showed better uniform packing in the polymer network structure as the CA concentration increases. The LSCM images (fluorescence and reflective mode) confirm the rheological results, and show different texture and aggregated structure for the gel as the structure of non-solvents are varied in the ternary system.
Forestry, Faculty of
Graduate
APA, Harvard, Vancouver, ISO, and other styles
6

Ko, Chan Uk. "Effect of surface treatment on the mechanical properties of the polysulfone-Al/Li bonded system including thin film studies of moisture intrusion and the viscoelastic response of the interphase region." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53556.

Full text
Abstract:
An investigation of polysulfone-Al/Li alloy interaction involved single lap shear joints and wedge samples following an FPL etch, sulfuric acid anodization (SAA) and phosphoric acid anodization (PAA). The study of the Al/Li surfaces involved the determination of the elemental composition and morphological features of the pretreated adherend before bonding and following failure. When thermoplastic polysulfone (PSF) was either thermally pressed or primed onto the microporous surface, the PSF indeed penetrated into the porous oxide and thereby provided a mechanical means of adhesion. The wedge test results for the adherend pretreated by PAA and SAA were superior to those for the FPL etched adherend. The failure path for the FPL etched samples was at the adhesive/oxide interface whereas the failure path for the SAA and PAA samples was within the adhesive but with occasional divergence of the crack into the oxide. The porous oxides on Al/Li alloy formed after PAA and SAA treatment were shown to undergo dramatic changes in morphology on short term (<90 hrs) exposure to 71 C and 100% R.H. environment. The mechanism of failure was due to moisture which caused slight hydration of the Al/Li oxide and subsequent debonding of the PSF from the oxide layer. Lithium was not concentrated at the surface in the PAA treated Al/Li alloy as shown by AES depth profiling. The effect of lithium on the durability of the bonded alloy is considered minimal. Along these lines, cyclic loading, use of primers, and infrared spectroscopy studies have been carried out. The mode of moisture intrusion into the polysulfone-Al/Li oxide interphase region is discussed. Specifically, water molecules diffuse into the polysulfone rather than transporting along the interface. Moisture then attacks the oxide interface. Thin polysulfone coatings on pretreated aluminum surfaces were characterized utilizing dynamic mechanical thermal analysis (DMTA), and dielectric thermal analysis (DETA) to detect changes in the molecular motions and structural transitions in the polysulfone-aluminum interphase. The order of the loss peak temperature of the polysulfone is, PSF coating on a porous Al > PSF coating on a smooth Al > neat PSF film. The activation energy of relaxation is also lower for neat PSF when compared to the thin film cast onto a smooth Al or a porous PAA Al substrate. The loss peak temperature shift and the higher activation energy associated with the coated films can be explained by the entropy being reduced when the chains are laid down in two dimensions. Thus studies of polymer properties in the interphase region will contribute to the understanding of the adhesive-adherend interaction.
Ph. D.
APA, Harvard, Vancouver, ISO, and other styles
7

McDermott, William J. "Adaptive properties in the dynamics of the human locomotor -respiratory system." 2005. https://scholarworks.umass.edu/dissertations/AAI3163688.

Full text
Abstract:
The purpose of this dissertation was to gain insight into the integration of the locomotory and respiratory systems by studying the coordinative behaviors that emerge in response to changing constraints. This was accomplished by utilizing analytical methods that have recently provided new insights into their adaptive strategies. Three studies were carried out that focused on different specific constraints that influence the interaction of the locomotory and respiratory systems. The first study investigated the relationship between stride frequency and locomotor-respiratory coordination (LRC) and the effect of LRC on the metabolic cost and ventilatory efficiency during running. It was found that stride frequency is a critical parameter affecting LRC and that the strength of LRC was not related to lower metabolic cost during running. In contrast, greater strength of coordination observed during running at preferred speed was associated with lower ventilatory efficiency. The second study examined the influence of mechanical constraints on LRC. The magnitude of mechanical perturbations imposed on the respiratory system by the upper body were not related to the strength of LRC. Instead, the timing within the stride cycle influenced the nature of LRC variability. It is likely that the coupling between these rhythms is not a passive mechanism but is related to active muscular control of the upper body, primarily influencing the variability of the coupling. The third study investigated the relationship between LRC and upper body control under normal and challenged postural and ventilatory conditions. These challenges resulted in significant changes in upper body control strategies including increases in the variability of motion. The postural challenge, however, did not act to further couple the respiratory rhythm to the locomotor rhythm and the ventilatory challenge did not act to decouple the rhythms. Together, the results of the current set of experiments illustrate the importance of variability in LRC and that mechanical constraints do not act to couple respiration to movement during human locomotion, as is typically assumed. Finally, the integration of upper body control and respiration has important implications for the study of gait stability.
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Viscoelastic respiratory system properties"

1

Thiriet, Marc. Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems. New York, NY: Springer New York, 2013.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Waite, Lee. Biofluid mechanics in cardiovascular systems. New York: McGraw-Hill, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Popow, C. Assessment of the Elastic Properties of the Respiratory System in the Newborn Infant. Smith-Gordon & Co Ltd, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Thiriet, Marc. Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems. Springer, 2013.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Thiriet, Marc. Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems. Springer, 2013.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Thiriet, Marc. Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems. Springer, 2016.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Carlucci, Annalisa, and Paolo Navalesi. Weaning failure in critical illness. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0103.

Full text
Abstract:
Weaning failure has been defined as failure to discontinue mechanical ventilation, as assessed by the spontaneous breathing trial, or need for re-intubation after extubation, so-called extubation failure. Both events represent major clinical and economic burdens, and are associated with high morbidity and mortality. The most important mechanism leading to discontinuation failure is an unfavourable balance between respiratory muscle capacity and the load they must face. Beyond specific diseases leading to loss of muscle force-generating capacity, other factors may impair respiratory muscle function, including prolonged mechanical ventilation, sedation, and ICU-acquired neuromuscular dysfunction, potentially consequent to multiple factors. The load depends on the mechanical properties of the respiratory system. An increased load is consequent to any condition leading to increased resistance, reduced compliance, and/or occurrence of intrinsic positive-end-expiratory pressure. Noteworthy, the load can significantly increase throughout the spontaneous breathing trial. Cardiac, cerebral, and neuropsychiatric disorders are also causes of discontinuation failure. Extubation failure may depend, on the one hand, on a deteriorated force-load balance occurring after removal of the endotracheal tube and, on the other hand, on specific problems. Careful patient evaluation, avoidance and treatment of all the potential determinants of failure are crucial to achieve successful discontinuation and extubation.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Viscoelastic respiratory system properties"

1

Milic-Emili, J., and E. D’Angelo. "Effects of Viscoelastic Properties of Respiratory System on Respiratory Dynamics." In Control of Breathing and Its Modeling Perspective, 341–45. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4757-9847-0_60.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Brandolese, R., and U. Andreose. "Altered elastic properties of the respiratory system." In Basics of Respiratory Mechanics and Artificial Ventilation, 191–200. Milano: Springer Milan, 1999. http://dx.doi.org/10.1007/978-88-470-2273-7_17.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Bakiya, A., K. Kamalanand, and R. L. J. De Britto. "Relationship between Viscoelastic and Dielectric Properties of Biological Soft Tissues." In Mechano-Electric Correlations in the Human Physiological System, 25–36. First edition. | Boca Raton, FL : CRC Press, 2021.: CRC Press, 2021. http://dx.doi.org/10.1201/9781003109181-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Deumić, Sara, Neira Crnčević, and Ivana Zolota. "Respiratory System Dynamical Mechanical Properties: Modeling in Time and Frequency Domain." In IFMBE Proceedings, 47–57. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-73909-6_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Gao, Yunzhu, Qiu Meng, Haojie Guo, Jing Li, and Changling Xu. "Study of Properties of Solutions for a Viscoelastic Wave Equation System with Variable-Exponents." In Lecture Notes in Electrical Engineering, 1420–26. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-3648-5_183.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Pałko, Krzysztof Jakub, Tomasz Gólczewski, Maciej Kozarski, Barbara Stankiewicz, and Marek Darowski. "A New Method and Device for Differentiating Elastic and Resistive Properties of the Respiratory System." In Advances in Intelligent Systems and Computing, 35–44. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-29885-2_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Davies, Andrew, and Carl Moores. "ELASTIC PROPERTIES OF THE RESPIRATORY SYSTEM." In The Respiratory System, 29–40. Elsevier, 2010. http://dx.doi.org/10.1016/b978-0-7020-3370-4.00003-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

BOOIJ, H. C., and J. H. M. PALMEN. "LINEAR VISCOELASTIC PROPERTIES OF A MISCIBLE POLYMER BLEND SYSTEM." In Theoretical and Applied Rheology, 321–23. Elsevier, 1992. http://dx.doi.org/10.1016/b978-0-444-89007-8.50132-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Villar, M. A., and E. M. Vallés. "Viscoelastic properties of model silicone networks with pendant chains." In Advances in Engineering Fluid Mechanics: Multiphase Reactor and Polymerization System Hydrodynamics, 599–614. Elsevier, 1996. http://dx.doi.org/10.1016/b978-088415497-6/50025-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Beris, Antony N., and Brian J. Edwards. "Incompressible Viscoelastic Fluids." In Thermodynamics of Flowing Systems: with Internal Microstructure. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195076943.003.0013.

Full text
Abstract:
In Part I, we discussed in detail the foundations of the bracket description of dynamical behavior, demonstrating how the generalized bracket is linked to the theories of both Hamiltonian mechanics and irreversible thermodynamics. Now it is time to discuss the various applications towards seemingly complex systems which are the main focus of this book. Specifically, we want to look at a variety of microstructured media of immediate concern in science and industry, and to illustrate the advantages of using the generalized bracket formalism over traditional techniques when developing system-particular models. As we shall also see, there are certain advantages to be gained even when we are simply expressing existing models in Hamiltonian form. The first subject that we wish to address is that of viscoelastic fluid dynamics. As the name implies, viscoelasticity characterizes the materials that possess properties intermediate to those of an elastic solid and a viscous fluid. The most characteristic property is that of limited (“fading”) memory: viscoelastic materials partially resume their previous deformation state upon removal of the externally applied forces; the smaller the duration of the application of the forces, the better the recovery. Materials of this type contain a certain degree of internal microstructure (e.g., polymeric solutions and melts, advanced composites, liquid crystals, etc.), and are very important in the processing industry where one wishes to combine the “processability” of the medium's fluidity with the “structural quality” of the internal architecture to obtain high strength/ low-weight final products. We can distinguish two types of viscoelasticity: viscoelastic solids and viscoelastic fluids characterized by the ability or lack of ability respectively, to support shear stresses at finite deformations. In the following we shall focus on the analysis of viscoelastic fluids although the approach followed applies and/or can be extended in a straightforward fashion to viscoelastic solids as well. For a description of solid viscoelasticity, the interested reader may consult one of the many excellent monographs in the area [Eringen, 1962, chs. 8, 10; Ferry, 1980; Sobotka, 1984; see also Tschoegl, 1989].
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Viscoelastic respiratory system properties"

1

Allen, Bradley R. "Direct complex stiffness test system for viscoelastic material properties." In 1996 Symposium on Smart Structures and Materials, edited by Conor D. Johnson. SPIE, 1996. http://dx.doi.org/10.1117/12.239101.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Reddy, Prasika I., Ahmed M. Al-Jumaily, and Geoff T. Bold. "A Viscoelastic Model of the Neonatal Respiratory System to Assess the Efficacy of CPAP Devices." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66212.

Full text
Abstract:
The objectives of this research were to; develop a validated mathematical model of the premature neonatal lung. A description of the multi-compartmental, branched airway model of the neonatal lung is presented and shown to compare well with existing in-vivo data from the literature. The model described will be used in engineering practice to assess the design of conventional and emerging forms of continuous positive airway pressure (CPAP) devices in treating respiratory distress syndrome (RDS) in premature neonates.
APA, Harvard, Vancouver, ISO, and other styles
3

Ghita, Maria, Dana Copot, Mihaela Ghita, Dirk Verellen, and Clara Mihaela Ionescu. "Parametric models for monitoring respiratory properties in lung cancer." In 2021 25th International Conference on System Theory, Control and Computing (ICSTCC). IEEE, 2021. http://dx.doi.org/10.1109/icstcc52150.2021.9607093.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Ohishi, J., H. Kurosawa, Y. Shimizu, Y. Tasaku, D. Kobayashi, M. Masuda, W. Hida, and M. Kohzuki. "Three Dimensional Color Images of Oscillatory Properties of Respiratory System." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a6074.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Bakiya, A., K. Kamalanand, S. Arunmozhi, and V. Rajinikanth. "Frequency Domain Modelling of Interrelation between Dielectric and Viscoelastic Properties of Soft Tissues." In 2020 International Conference on System, Computation, Automation and Networking (ICSCAN). IEEE, 2020. http://dx.doi.org/10.1109/icscan49426.2020.9262392.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Mulligan, K., A. Adler, and R. Goubran. "Detecting regional lung properties using audio transfer functions of the respiratory system." In 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2009. http://dx.doi.org/10.1109/iembs.2009.5333107.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Evrensel, Cahit A., Amgad A. Hassan, and Peter E. Krumpe. "An Experimental Investigation of Interaction of Airflow With a Viscoelastic Layer." In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-0046.

Full text
Abstract:
Abstract The respiratory tract of mammals is lined with a layer of mucus, described as a viscoelastic semi-solid, above a layer of watery serous layer. For a healthy person, rhythmic beating action of cilia propels the mucus layer continually. Dehydration results in the disappearance of serous layer and impairs the mucociliary clearance. These persons must relay on the two-phase gas-liquid flow and cough as the clearance mechanism. In this study, the interaction of airflow with a mucus simulant in a channel is investigated experimentally. Locust Bean Gum and Borax dissolved in deionized water is used as the mucus simulant. Two types of instability mechanisms are observed. The first is the propagating waves that appear at relatively low air speed and the catastrophic clearance that resembles an avalanche. The results show that onset flow speeds for both instabilities are sensitive to the layer thickness and decrease with the increasing thickness. Onset for the clearance does not seem to be sensitive to the viscoelastic properties of the mucus simulant.
APA, Harvard, Vancouver, ISO, and other styles
8

Carvalho, Rodrigo S., Ana Flávia G. D. C. Nunes, Rebecca M. Barbosa, Izabella B. D. O. Ferreira, and César Augusto M. Silva. "Repercussions Of The Portopulmonary Syndrome In The Mechanical Properties Of The Respiratory System Of Rats." In American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California. American Thoracic Society, 2012. http://dx.doi.org/10.1164/ajrccm-conference.2012.185.1_meetingabstracts.a4764.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Shibuya, Yotsugi. "Viscoelastic Homogenization Approach for Damping Properties of Polymer Composites Using Fractional Calculus." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-4928.

Full text
Abstract:
Polymer composites are attractive material system with damping ability to reduce vibration of mechanical structures and improve controllability of mechanical system. To understand effect of constituents and microstructure on damping properties of polymer composites, a detailed micromechanical study is needed to develop the method of analysis for microscopic viscoelastic deformation and macroscopic damping properties. Viscoelastic homogenization approach with fractional calculus is developed to evaluate effective damping properties of polymer composites. The microstructure of the composite is supposed to be periodic and polymer matrix is viscoelastic medium. Damping properties of the composite are evaluated from the stress strain diagram and associated energy dissipation during cyclic loading. Viscoelastic properties of the polymer matrix are identified using a generalized fractional Maxwell model with spring and fractional elements. Coefficients of elements in the generalized fractional Maxwell model are determined to be fitting into experimental data in frequency domain. The homogenized stress strain relation in time domain given by inverse Laplace transform is derived and numerical calculations are carried out.
APA, Harvard, Vancouver, ISO, and other styles
10

Al-Jumaily, A. M., and P. Mithraratne. "Simulation of Respiratory System for Identifying Airway Occlusion." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2594.

Full text
Abstract:
Abstract Respiratory disorders are common in both developed and developing countries. Many of these disorders are directly connected to constrictions in the airways of the human respiratory system. Asthma and bronchitis are typical examples that arise from the constriction of airways. The respiratory system consists of a series of branching tubes which become narrower, shorter and more numerous as they penetrate deeper into the lung. This branching network found within the multiple succussive bifurcation of the pulmonary tree has received theoretical attention [1]. Several attempts have been made to investigate the characteristics of healthy and unhealthy lungs. Some of them theoretical [2–5] while others are experimental [6,7]. The acoustical approach has been considered as one of the leading theoretical approaches to date. This approach is based on linking the acoustical impedance between the branches by using recursive formulae [2]. None of the available references has investigated the effect of occlusions in a branch on the behaviour of the whole respiratory system. Further, the work reported on the dynamic modelling of the respiratory system has overlooked, with the exception of [5], mechanical and physical properties of the airway walls, which are believed to have a considerable impact on the overall dynamics of the system.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Viscoelastic respiratory system properties"

1

Freed, Alan D., Daniel R. Einstein, James P. Carson, and Rick E. Jacob. Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System, Phase II: Dodecahedral Micro-Model. Office of Scientific and Technical Information (OSTI), March 2012. http://dx.doi.org/10.2172/1040678.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Freed, Alan D., and Daniel R. Einstein. Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System Phase I: Hypo-Elastic Model for CFD Implementation. Office of Scientific and Technical Information (OSTI), April 2011. http://dx.doi.org/10.2172/1013297.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Viscoelastic respiratory system properties' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography