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PURPOSE: The aim of the present study was to visualize and compare the cavitation effect and fluid dynamics induced by photon-induced photoacoustic streaming (PIPS) using sodium hypochlorite (NaOCl) with different concentrations as irrigant. METHODS: Forty artificial root canals were prepared using MTWO Niti file up to size #25/.06. The canals were randomly divided into four groups (n = 10/group). High-speed camera was used to visualize and compare the cavitation effect induced by PIPS in the artificial root canals containing saline or NaOCl. Fluid velocity and Reynolds number of saline, 1%-, 2.5%- and 5.25% NaOCl irrigants induced by PIPS in the apical region were calculated using TEMA 2D software while the fluid motions were recorded. RESULTS: Visualization profile revealed that NaOCl presented a stronger cavitation effect and fluid dynamics than saline during PIPS activation. In the apical region, 1% NaOCl group presented the highest average velocity of 3.868 m/s, followed by 2.5% NaOCl group (3.685 m/s), 5.25% NaOCl group (2.353 m/s) and saline group (1.268 m/s), corresponding to Reynolds number of 1653.173, 1572.196, 995.503 and 477.692. Statistically higher fluid velocity was calculated in 1% and 2.5% NaOCl groups compared to saline group, respectively (p < 0.05). CONCLUSIONS: The application of NaOCl and its concentration significantly influence the cavitation effect and fluid dynamics during PIPS activation. 1% and 2.5% NaOCl groups presented a more violent fluid motion in the apical region when activated by PIPS.
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Irrigantes do Canal Radicular , Hipoclorito de Sódio , Cavidade Pulpar , Hidrodinâmica , Fótons/uso terapêutico , Irrigantes do Canal Radicular/farmacologia , Preparo de Canal Radicular , Hipoclorito de Sódio/farmacologiaRESUMO
This work investigates the interstitial fluid flow characteristics in a solid tumor with partial fluid leakage at the tumor surface subjected to oscillatory microvascular pressure. Solutions of the pore fluid pressure and velocity in a spherical tumor are obtained using the poroelasticity theory for small strains. It is found that partial fluid leakage at the tumor surface reduces the pore pressure drop and decreases the fluid velocity near the surface compared with those in a tumor with a fully leaking surface. Both the pore pressure and the fluid velocity decrease dramatically with an increase in the vascular frequency. The pore pressure at a vascular frequency of 1 Hz is two orders of magnitude smaller than the amplitude of the vascular pressure, and the fluid velocity at the same frequency is one order of magnitude smaller than that produced by the steady constant vascular pressure. The pore pressure amplitude may reach that of the vascular pressure under the steady state vascular pressure condition.
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Pressão Sanguínea , Líquido Extracelular/metabolismo , Microvasos/fisiopatologia , Modelos Cardiovasculares , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Animais , Velocidade do Fluxo Sanguíneo , Elasticidade , Humanos , Pressão Hidrostática , PorosidadeRESUMO
This study investigated how air bubbles in media affect tablet dissolution in a flow-through cell system (USP 4) using disintegrating (USP prednisone) and non-disintegrating (USP salicylic acid) tablets. Cell hydrodynamics were studied using particle image velocimetry (PIV) and computational fluid dynamics (CFD). The PIV analysis showed periodic changes in the local flow corresponding to the discharge and suction of the pump cycles. The absence of prior deaeration induced small air bubbles in the media and lower maximum flow during the cycle, explaining the slower dissolution of the USP salicylic acid tablets. Bubbles, occurring during the USP prednisone tablets study, induced the transition of floating disintegrated particles towards the cell outlet, whereas the particles precipitated to form a white layer on the glass beads used in the study with prior deaeration. CFD analysis showed local flow variation in multiple positions of small (ID 12 mm) and large (ID 22.6 mm) cells, explaining the different rates of dissolution of prednisone tablet particles depending on their distribution. These results emphasize the importance of prior deaeration in dissolution studies using a flow-through system. Bubbles in the flow-through cell system affected tablet dissolution by reducing the area in contact with the media (wettability), lowering the maximum instantaneous flow (pressure buffering), and altering the position of disintegrated particles in the cell.
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Hidrodinâmica , Ácido Salicílico , Comprimidos , Reologia , SolubilidadeRESUMO
At present, autonomous underwater vehicles (AUVs) cannot perceive local environments in complex marine environments, where fish can obtain hydrodynamic information about the surrounding environment through a lateral line. Inspired by this biological function, an artificial lateral line system (ALLS) was built on a moving bionic carrier using the pressure sensor in this paper. When the carrier operated with different speeds in the flow field, the pressure distribution characteristics surrounding the carrier were analyzed by numerical simulation, where the effect of the flow angle between the fluid velocity direction and the carrier navigation direction was considered. The flume experiment was carried out in accordance with the simulation conditions, and the analysis results of the experiment were consistent with those in the simulation. The relationship between pressure and fluid velocity was established by a fitting method. Subsequently, the pressure difference method was investigated to establish a relationship model between the pressure difference on both sides of the carrier and the flow angle. Finally, a back propagation neural network model was used to predict the fluid velocity, flow angle, and carrier speed successfully in the unknown fluid environment. The local fluid environment perception by moving carrier carrying ALLS was studied which may promote the engineering application of the artificial lateral line in the local perception, positioning, and navigation on AUVs.
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An acoustic Doppler velocimeter (ADV) was used to analyse the impact of an agricultural sprayer's agitation system settings on fluid velocities inside the tank. A 3000 L capacity sprayer equipped with a 4-nozzle hydraulic agitation system was used. ADV measurements were carried at 32 points inside the tank under the following settings: circuit pressures of 8, 10, or 12 bar; water level in the tank of 1000, 2000, or 3000 L; 2 or 4 active nozzles. An agitation test with a concentration of 0.4% copper oxychloride was employed to analyse the concentration of active matter as a function of tank fill level and number of active nozzles. All parameters significantly affected the fluid velocity, which increased with increasing pressure, but decreased with increasing water level in the tank and an increased number of active nozzles. Concentration tests showed greater active matter concentrations when higher velocities were recorded by the ADV. The ADV was shown to be a useful tool for the rapid assessment of fluid velocities; in the future, it could be used to validate the design of agitation systems, and to estimate their capacity to ensure an adequate level of active matter concentration in the fluid.
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In this article, a new method was developed to measure the velocity of a fluid using a sensor, based on the use of a spherical parallel mechanism with three degrees-of-freedom (DOF). This sensor transforms the kinetic energy of the fluid into potential energy by deforming the parallel mechanism. This deformation is due to the impact of the fluid on a sphere attached to the platform of the parallel mechanism. Through the acquisition of data from a sensor using an inertial measurement unit (IMU) in the sphere, an algorithm calculates the velocity and direction of the fluid. In this article, a mathematical model of the mechanism and an algorithm for correctly measuring the velocity and direction of the fluid is developed; this algorithm is tested through a simulation in the Adams software, and the MATLAB software is used to execute the algorithm. The results show that the algorithm calculates the velocity and the direction of the fluid correctly, demonstrating the technical feasibility of the sensor.
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There are few methods to provide high-resolution in-situ characterization of flow in aquifers and reservoirs. We present a method that has the potential to quantify lateral and vertical (magnitude and direction) components of flow with spatial resolution of about one meter and temporal resolution of about one day. A fiber optic distributed temperature sensor is used with a novel heating system. Temperatures before heating may be used to evaluate background geothermal gradient and vertical profile of thermal diffusivity. The innovation presented is the use of variable energy application along the well, in this case concentrated heating at equally-spaced (2 m) localized areas (0.5 m). Relative to uniform warming this offers greater opportunity to estimate water movement, reduces required heating power, and increases practical length that can be heated. Numerical simulations are presented which illustrate expected behaviors. We estimate relative advection rates near the well using the times at which various locations diverge from a heating trajectory expected for pure conduction in the absence of advection. The concept is demonstrated in a grouted 600 m borehole with 300 heated patches, though evidence of vertical water movement was not seen.
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The lab-scale and full-scale performance of a combined mesophilic up-flow anaerobic sludge blanket (UASB) and aerobic contact oxidation (ACO) process for treating acrylic wastewater was studied. During lab-scale experiment, the overwhelmed volumetric load for UASB was above 6â kg chemical oxygen demand (COD) ·(m(-3)·d(-1)) since COD removal efficiency dropped dramatically from 73% at 6â kg COD·(m(-3)·d(-1)) to 61% at 7â kg COD·(m(-3)·d(-1)) and 53% at 8â kg COD·(m(-3)·d(-1)). Further results showed that an up-flow fluid velocity of 0.5â mâ h(-1) for UASB obtained a highest COD removal efficiency of 75%, and the optimum COD volumetric load for the corresponding ACO was 1.00â kg COD·(m(-3)·d(-1)). Based on the configuration of the lab-scale experiment, a full-scale application with an acrylic wastewater treatment capacity of 8â m3â h(-1) was constructed and operated at a volumetric load of 5.5â kg COD·(m(-3)·d(-1)), an up-flow fluid velocity of 0.5â mâ h(-1) for UASB and a volumetric load of 0.9â kg COD·(m(-3)·d(-1)) for ACO; and the final effluent COD was around 740â mgâ L(-1). The results suggest that a combined UASB-ACO process is promising for treating acrylic wastewater.
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Eliminação de Resíduos Líquidos/métodos , Acrilatos , Análise da Demanda Biológica de Oxigênio , Resíduos Industriais , Oxirredução , Eliminação de Resíduos Líquidos/economia , Águas ResiduáriasRESUMO
Osteoporosis and disuse can cause bone loss which reduces the weight-bearing strength of long bones. Physical exercise or mechanical loading prevents bone loss as it promotes bone modeling through osteogenesis, i.e., new bone formation. Several studies have observed distinct bone remodeling responses to physical exercises; nevertheless, the underlying mechanism behind such responses is not well established. Loading-induced pore-pressure and fluid motion act as mechanobiological stimuli to bone cells namely osteocytes which further initiate osteoactivities. The shape of loading waveforms also affects the poromechanical environment of bone. Accordingly, the present study hypothesizes that loading waveforms associated with physiological exercises may expose the bone to different mechanobiological stimuli resulting in distinct bone remodeling. A poromechanical finite element model is developed to compute pore-pressure and interstitial fluid velocity in femoral cortical bone tissue (healthy and osteoporotic) subjected to loading waveforms of three physiological exercises namely walking, running, and jumping. The model also computes the mechanobiological stimulus as a function of fluid velocity. The outcomes indicate that pore-pressure and fluid velocity decrease significantly in osteoporotic bone tissue in comparison with healthy tissue. Jumping and running both improve pore-pressure and fluid velocity in healthy and osteoporotic tissues, whereas running significantly enhances mechanobiological stimulus in both the tissues which indicates a possible explanation for distinct bone remodeling to different physical exercises. The present work also suggests that running may be recommended as a potential biomechanical therapeutic to prevent bone loss. Overall, the present work contributes to the area of orthopedic research to develop effective designs of prophylactic exercises to improve bone health.
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Modelos Biológicos , Osteogênese , Humanos , Caminhada , Simulação por Computador , Remodelação Óssea/fisiologiaRESUMO
BACKGROUND AND OBJECTIVES: Physiological loading-induced mechanical environments regulate bone modeling and remodeling. Thus, loading-induced normal strain is typically considered a stimulus to osteogenesis. However, several studies noticed new bone formation near the sites of minimal normal strain, e.g., the neutral axis of bending in long bones, which raises a question on how bone mass is maintained near these sites. Secondary mechanical components such as shear strain and interstitial fluid flow also stimulate bone cells and regulate bone mass. However, the osteogenic potential of these components is not well established. Accordingly, the present study estimates the distribution of physiological muscle loading-induced mechanical environments such as normal strain, shear strain, pore pressure, and interstitial fluid flow in long bones. METHODS: A poroelastic finite element muscle standardized femur (MuscleSF) model is developed to compute the distribution of the mechanical environment as a function of bone porosities associated with osteoporotic and disuse bone loss. RESULTS: The results indicate the presence of higher shear strain and interstitial fluid motion near the minimal strain sites, i.e., the neutral axis of bending of femoral cross-sections. This suggests that secondary stimuli may maintain the bone mass at these locations. Pore pressure and interstitial fluid motion reduce with the increased porosity associated with bone disorders, possibly resulting in diminished skeletal mechano-sensitivity to exogenous loading. CONCLUSIONS: These outcomes present a better understanding of mechanical environment-mediated regulation of site-specific bone mass, which can be beneficial in developing prophylactic exercise to prevent bone loss in osteoporosis and muscle disuse.
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Líquido Extracelular , Osteoporose , Humanos , Líquido Extracelular/fisiologia , Osso e Ossos , Músculo Esquelético , Fêmur , Estresse MecânicoRESUMO
The objective of this study is to numerically investigate the thermal performance of cutting fluids dispersed with nanoparticles for effective heat removal during turning operations. The simulations are performed using Ansys Fluent software, and the problem is modelled as a three-dimensional turbulent incompressible single-phase flow. The computational domain consists of a heated cutting tool and work piece, and nanocoolants are sprayed from a nozzle located above the machining zone. The nanocoolants are prepared by mixing mineral oil with nanoparticles of Al2O3 (Aluminium Oxide), Al (Aluminium) and SWCNT (Single Walled Carbon Nanotube). The heat transfer performances of different nanocoolants are compared by varying the nanoparticle volume fraction (φ) and coolant velocity (Uc) in the range of 2% ≤ φ ≤ 8% and 1 m/s ≤ Uc ≤ 15 m/s, respectively. The results indicated a drastic drop in the cutting tool temperature with an increase in the volume fraction of dispersed nanoparticles and coolant velocity. The increase in volume fraction decreases the average cutting tool temperature by 25.65% and also enhances the average heat transfer rate by 25.43%. It is additionally observed that SWCNT nanocoolants exhibited a superior thermal performance and heat removal rate compared with Al and Al2O3 nanocoolants. The analysed numerical results are validated and are in good accordance with the benchmark results validated from literature.
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The 11α-hydroxylation of canrenone can be catalyzed by Aspergillus ochraceus in bioreactors, where the geometry of the impeller greatly influences the biotransformation. In this study, the effects of the blade number and impeller diameter of a Rushton turbine on the 11α-hydroxylation of canrenone were considered. The results of fermentation experiments using a 50 mm four-blade impeller showed that 3.40% and 11.43% increases in the conversion ratio were achieved by increasing the blade number and impeller diameter, respectively. However, with an impeller diameter of 60 mm, the conversion ratio with a six-blade impeller was 14.42% lower than that with a four-blade impeller. Data from cold model experiments with a large-diameter six-blade impeller indicated that the serious leakage of inclusions and a 22.08% enzyme activity retention led to a low conversion ratio. Numerical simulations suggested that there was good gas distribution and high fluid flow velocity when the fluid was stirred by large-diameter impellers, resulting in a high dissolved oxygen content and good bulk circulation, which positively affected hyphal growth and metabolism. However, a large-diameter six-blade impeller created overly high shear compared to a large-diameter four-blade impeller, thereby decreasing the conversion ratio. The average shear rates of the former and latter cases were 43.25 s-1 and 35.31 s-1, respectively. We therefore concluded that appropriate shear should be applied in the 11α-hydroxylation of canrenone. Overall, this study provides basic data for the scaled-up production of 11α-hydroxycanrenone.
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Reatores Biológicos , Canrenona/metabolismo , Aspergillus ochraceus/crescimento & desenvolvimento , Aspergillus ochraceus/metabolismo , Biotransformação , Canrenona/química , Meios de Cultura/química , Meios de Cultura/metabolismo , Fermentação , Hidroxilação , Hifas/crescimento & desenvolvimento , Hifas/metabolismo , Modelos TeóricosRESUMO
It is well known that transport of nutrients and wastes as solute in bone fluid plays an important role in bone remodeling and damage healing. This work presents a chemo-poroelastic model for fluid and solute transport in the lacunar-canalicular network of an osteonal cortical bone under cyclic axial mechanical loading or vascular pressure. Analytical solutions are obtained for the pore fluid pressure, and fluid and solute velocities. Numerical results for fluid and calcium transport indicate that under a cyclic stress of 20 MPa, the magnitudes of the fluid and calcium velocities increase with an increase in the loading frequency for the frequency range considered (≤ 3 Hz) and peak at the inner boundary. The peak magnitude of calcium velocity reaches 18.9 µm/s for an osteon with a permeability of 1.5 × 10-19 m2 under a 3 Hz loading frequency. The magnitude of calcium velocity under a vascular pressure of 50 mmHg is found to be two orders of magnitude smaller than that under the mechanical load. These results have the potential to be important in understanding fundamental aspects of cortical bone remodeling as transport characteristics of calcium and other nutrients at the osteon scale influence bone metabolism.
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Ósteon/fisiologia , Modelos Biológicos , Cálcio , Elasticidade , Líquido Extracelular , Porosidade , Solventes , Estresse MecânicoRESUMO
The nucleus pulposus (NP) in the intervertebral disk (IVD) depends on diffusive fluid transport for nutrients through the cartilage endplate (CEP). Disruption in fluid exchange of the NP is considered a cause of IVD degeneration. Furthermore, CEP calcification and sclerosis are hypothesized to restrict fluid flow between the NP and CEP by decreasing permeability and porosity of the CEP matrix. We performed a finite element analysis of an L3-L4 lumbar functional spine unit with poro-elastic constitutive equations. The aim of the study was to predict changes in the solid and fluid parameters of the IVD and CEP under structural changes in CEP. A compressive load of 500 N was applied followed by a 10 Nm moment in extension, flexion, lateral bending, and axial rotation to the L3-L4 model with fully saturated IVD, CEP, and cancellous bone. A healthy case of L3-L4 physiology was then compared to two cases of CEP sclerosis: a calcified cartilage endplate and a fluid constricted sclerotic cartilage endplate. Predicted NP fluid velocity increased for the calcified CEP and decreased for the calcified + less permeable CEP. Decreased NP fluid velocity was prominent in the axial direction through the CEP due to a less permeable path available for fluid flux. Fluid pressure and maximum principal stress in the NP were predicted to increase in both cases of CEP sclerosis compared to the healthy case. The porous medium predictions of this analysis agree with the hypothesis that CEP sclerosis decreases fluid flow out of the NP, builds up fluid pressure in the NP, and increases the stress concentrations in the NP solid matrix.
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Cartilagem/fisiopatologia , Elasticidade , Análise de Elementos Finitos , Núcleo Pulposo/fisiopatologia , Reologia , Esclerose/fisiopatologia , Cartilagem/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Disco Intervertebral/fisiopatologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Núcleo Pulposo/diagnóstico por imagem , Permeabilidade , Porosidade , Pressão , Reprodutibilidade dos Testes , Esclerose/diagnóstico por imagem , Estresse Mecânico , Tomografia Computadorizada por Raios XRESUMO
The behaviour of subsurface-reservoir porous rocks is a central topic in the resource engineering industry and has relevant applications in hydrocarbon, water production, and CO2 sequestration. One of the key open issues is the effect of deformation on the hydraulic properties of the host rock and, specifically, in saturated environments. This paper presents a novel full-field data set describing the hydro-mechanical properties of porous geomaterials through in situ neutron and X-ray tomography. The use of high-performance neutron imaging facilities such as CONRAD-2 (Helmholtz-Zentrum Berlin) allows the tracking of the fluid front in saturated samples, making use of the differential neutron contrast between "normal" water and heavy water. To quantify the local hydro-mechanical coupling, we applied a number of existing image analysis algorithms and developed an array of bespoke methods to track the water front and calculate the 3D speed maps. The experimental campaign performed revealed that the pressure-driven flow speed decreases, in saturated samples, in the presence of pre-existing low porosity heterogeneities and compactant shear-bands. Furthermore, the observed complex mechanical behaviour of the samples and the associated fluid flow highlight the necessity for 3D imaging and analysis.
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Objective: This study aimed to examine the irrigant flow generated by laser-activated irrigation (LAI), in comparison with ultrasonic-activated irrigation (UAI) and syringe irrigation (SI), in the area beyond the ledge using particle image velocimetry (PIV). Background data: There was no reported study about cleaning efficacy of LAI beyond the ledge. Materials and methods: Forty-nine J-shaped root canal models (40° curvature) were instrumented to no. 35/0.06, and a ledge, 2.5 mm deep, was created with no. 60/0.08 instrument at 5 mm from the apical foramen in each canal. The samples were irrigated with LAI [30 mJ/5 pulse per second (pps), 30 mJ/10 pps, 30 mJ/20 pps, 50 mJ/10 pps, 70 mJ/10 pps], UAI, and SI with a tip/needle insertion depth of 5 mm from the apical foramen (n = 7). PIV was performed with glass beads and a high-speed camera. Velocities were compared in the coronal and apical areas to the ledge, respectively. Results: In the apical area, all LAI groups and UAI produced a higher velocity than that of SI, and LAI at 30 mJ/20 pps and 70 mJ/10 pps showed significantly higher velocity than that of UAI (p < 0.05). In the coronal area, LAI at 30 mJ/20 pps generated a significantly higher velocity than that of UAI and SI (p < 0.05). Velocity was significantly slower in the apical area than in the coronal area in UAI and SI (p < 0.05), but was similar between both areas in LAI except at 30 mJ/20 pps. Conclusions: Among tested laser settings, higher velocity was significantly achieved by LAI at 30 mJ/20 pps and 70 mJ/10 pps compared with UAI in the canal area beyond the ledge. SI generated lower fluid movement than LAI and UAI in both canal regions.
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Lasers de Estado Sólido/uso terapêutico , Terapia com Luz de Baixa Intensidade , Reologia/efeitos da radiação , Preparo de Canal Radicular , Ápice Dentário/efeitos da radiação , Humanos , Modelos Biológicos , Irrigação TerapêuticaRESUMO
Droplet-based microfluidic assisted devices have proposed an extensive interest in many applications such as lab-on-a-chip technologies as well as chemical/biological/nanomaterial preparation, chemical engineering, drug delivery, tissue engineering and biosensing. Here, a computational fluid dynamic model was developed for deep understanding of the droplet size and formation in a flow-focusing (FF) microchannel with consideration of the continuous phase (non-Newtonian fluid). The simulations presented an alternative method to achieve insights into this complicated process. In the following for the first time, the role of channel geometry, channel aspect ratio and flow rate ratio on droplet features including the mechanism of droplet formation, diameter/volume of droplet, velocity/amount of droplet formation, and final shape/size of the generated droplets were fully described. These findings could remarkably derive desirable protocols to control droplets characteristics comprising their size and shape in non-Newtonian fluids. Moreover, level set (LS) method was used for scrutinizing the droplet-breaking procedure in the microfluidic FF devices. The results showed that different droplet sizes could be prepared with changing the various parameters, demonstrating many challenges in various applications including lab-on-a-chip, cell encapsulation, drug delivery, tissue engineering, biosensing and bioimaging could be successfully addressed.
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Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas , Modelos TeóricosRESUMO
Atmospheric pressure chemical vapor deposition (APCVD) has been used extensively for synthesizing two-dimensional (2D) materials because of its low cost and promise for high-quality monolayer crystal synthesis. However, the understanding of the reaction mechanism and the key parameters affecting the APCVD processes is still in its embryonic stage. Hence, the scalability of the APCVD method in achieving large-scale continuous film remains very poor. Here, we use MoSe2 as a model system and present a fluid guided growth strategy for understanding and controlling the growth of 2D materials. Through the integration of experiment and computational fluid dynamics (CFD) analysis in the full-reactor scale, we identified three key parameters, precursor mixing, fluid velocity, and shear stress, which play a critical role in the APCVD process. By modifying the geometry of the growth setup to enhance precursor mixing and decrease nearby velocity shear rate and adjusting flow direction, we have successfully obtained inch-scale monolayer MoSe2. This unprecedented success of achieving scalable 2D materials through fluidic design lays the foundation for designing new CVD systems to achieve the scalable synthesis of nanomaterials.
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In this work, surface/interface effects for pull-in voltage and viscous fluid velocity effects on the dimensionless natural frequency of fluid-conveying multiwalled piezoelectric nanosensors (FC-MWPENSs) based on cylindrical nanoshells is investigated using the Gurtin-Murdoch surface/interface theory. The nanosensor is embedded in a viscoelastic foundation and subjected to nonlinear van der Waals and electrostatic forces. Hamilton's principle is used to derive the governing and boundary conditions and is also the assumed mode method used for changing the partial differential equations into ordinary differential equations. The influences of the surface/interface effect, such as Lame's constants, residual stress, piezoelectric constants and mass density, are considered for analysis of the dimensionless natural frequency with respect to the viscous fluid velocity and pull-in voltage of the FC-MWPENSs.
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Fluid pressure and fluid velocity carry important information for cancer diagnosis, prognosis and treatment. Recent work has demonstrated that estimation of these parameters is theoretically possible using ultrasound poroelastography. However, accurate estimation of these parameters requires high quality axial and lateral strain estimates from noisy ultrasound radio frequency (RF) data. In this paper, we propose a filtering technique combining two efficient filters for removal of noise from strain images, i.e., Kalman and nonlinear complex diffusion filters (NCDF). Our proposed filter is based on a novel noise model, which takes into consideration both additive and amplitude modulation noise in the estimated strains. Using finite element and ultrasound simulations, we demonstrate that the proposed filtering technique can significantly improve image quality of lateral strain elastograms along with fluid pressure and velocity elastograms. Technical feasibility of the proposed method on an in vivo set of data is also demonstrated. Our results show that the CNRe of the lateral strain, fluid pressure and fluid velocity as estimated using the proposed technique is higher by at least 10.9%, 51.3% and 334.4% when compared to the results obtained using a Kalman filter only, by at least 8.9%, 27.6% and 219.5% when compared to the results obtained using a NCDF only and by at least 152.3%, 1278% and 742% when compared to the results obtained using a median filter only for all SNRs considered in this study.