scholarly journals Study on Deposition Characteristics of Microparticles in Terminal Pulmonary Acini by IB–LBM

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 957
Author(s):  
Du-Chang Xu ◽  
Yu-Xiao Luo ◽  
Yuan-Qing Xu
Keyword(s):  
Respiratory Rate ◽  
Reference Value ◽  
Deposition Process ◽  
Immersed Boundary ◽  
Aerosol Delivery ◽  
Movement Model ◽  
Particulate Pollution ◽  
Dynamic Correlation ◽  
Depth Study ◽  
Gravity Direction

As an indicator of health risk, the deposition of microparticles in terminal pulmonary acini is of great significance in the medical field. To control particulate pollution and optimize aerosol delivery, it is necessary to perform an in-depth study of the microparticle deposition in terminal pulmonary acini; however, little research has been done on this topic. This paper proposes a respiratory movement model of terminal pulmonary acini using an immersed boundary–lattice Boltzmann method. In addition, we explored the effect of gravity direction, respiratory rate, microparticle diameter, and other parameters on the microparticles deposition process and distribution, under the airflow in the acinar wall. It was found that the deposition of microparticles is sensitive to gravity direction, and the growth of the respiratory rate increases the rate of microparticle migration and deposition. It was observed that the gravity effect is enhanced by increasing the diameter of microparticles, causing a high deposition and dispersion rate. The study reveals the dynamic correlation between the respiration process and the movement of microparticles, which is of reference value to figure out the pathogenicity mechanism of inhalable particles and to optimize the aerosol delivery.

Study on Crack Mechanism for Concrete Bedding Cushion on Rock

2010 ◽  
Vol 163-167 ◽  
pp. 1291-1295 ◽  
Author(s):  
Min Zhi Liu ◽  
Sheng Qiang ◽  
Zhen Yang Zhu
Keyword(s):  
Tensile Stress ◽  
Great Influence ◽  
Reference Value ◽  
Mass Concrete ◽  
Prevention Measures ◽  
Concrete Dam ◽  
Depth Study ◽  
Calculation Results ◽  
Cushion Layer ◽  
Cooling Pipes

Bedding cushion cracking in concrete dam is widespread, and has not been completely prevented [1,2]. There are many cracking causes of bedding cushion, including construction difficulty and structure requirements for concrete dam. Based on the method of FEM simulative calculation of temperature and stress fields of mass concrete using water cooling pipes, this paper makes relatively in-depth study on crack mechanism for concrete bedding cushion on rock. It is revealed that all three factors of uneven thickness of bedding cushion, thickness of new dam concrete placed on cushion after off period and foundation gallery upon bedding cushion have great influence on the tensile stress of bedding cushion and should be paid special attention during construction. The calculation results show that the tensile stress of thinner concrete cushion layer is much greater than the thicker one, and the thinner upon new concrete will also make greater tensile stress in cushion. As a result, both the thinner cushion layer and the cushion with thinner new concrete on it would have a bigger chance to crack than others. The mechanism is used to explain reasonably a dam crack in construction. Then some cracking prevention measures, which should have reference value for the construction of bedding cushion, are put forward in this paper.

The Design and Implementation of Prototype System for Choreography and Rehearsed Based on Virtual Simulation Technology

2015 ◽  
Vol 713-715 ◽  
pp. 2495-2498
Author(s):  
Hua Juan Ji ◽  
Jian Bo Zhao ◽  
Huan Zhao
Keyword(s):  
Structure And Function ◽  
Crowd Simulation ◽  
Prototype System ◽  
Virtual Reality Technology ◽  
Movement Model ◽  
Design And Implementation ◽  
The Third ◽  
Depth Study ◽  
And Function ◽  
Crowd Movement

This paper use crowd simulation and virtual reality technology design choreography prototype system. Based on the analysis and research of group calisthenics performance’s choreography work draws the related theory of crowd movement model, proposes a crowd movement model which can describe actor behavior in group calisthenics. This paper is divided into three parts; the first part introduces the development of group gymnastics in China. The second part introduces the structure and function of group calisthenics prototype system. The third part focuses on the design and implementation of a prototype, at the same time provides a useful reference for depth study of virtual crowd simulation.

scholarly journals Non-contact physiological monitoring of post-operative patients in the intensive care unit

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
João Jorge ◽  
Mauricio Villarroel ◽  
Hamish Tomlinson ◽  
Oliver Gibson ◽  
Julie L. Darbyshire ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Vital Sign ◽  
Vital Signs ◽  
Reference Value ◽  
Absolute Error ◽  
Video Camera ◽  
Clinical Observations ◽  
Operative Care ◽  
Respiratory Events

AbstractProlonged non-contact camera-based monitoring in critically ill patients presents unique challenges, but may facilitate safe recovery. A study was designed to evaluate the feasibility of introducing a non-contact video camera monitoring system into an acute clinical setting. We assessed the accuracy and robustness of the video camera-derived estimates of the vital signs against the electronically-recorded reference values in both day and night environments. We demonstrated non-contact monitoring of heart rate and respiratory rate for extended periods of time in 15 post-operative patients. Across day and night, heart rate was estimated for up to 53.2% (103.0 h) of the total valid camera data with a mean absolute error (MAE) of 2.5 beats/min in comparison to two reference sensors. We obtained respiratory rate estimates for 63.1% (119.8 h) of the total valid camera data with a MAE of 2.4 breaths/min against the reference value computed from the chest impedance pneumogram. Non-contact estimates detected relevant changes in the vital-sign values between routine clinical observations. Pivotal respiratory events in a post-operative patient could be identified from the analysis of video-derived respiratory information. Continuous vital-sign monitoring supported by non-contact video camera estimates could be used to track early signs of physiological deterioration during post-operative care.

Trajectory Planning for a Articulated Robot

2015 ◽  
Vol 742 ◽  
pp. 576-581
Author(s):  
Kai Kai Wang ◽  
Jia Qi Li ◽  
Yuan Wei Zou ◽  
Cheng Li Wang ◽  
Liu Bo Liang
Keyword(s):  
Trajectory Planning ◽  
Reference Value ◽  
Matlab Simulation ◽  
Robot Trajectory ◽  
Starting Point ◽  
Depth Study ◽  
Planning Algorithm ◽  
Articulated Robot ◽  
Path Planning Algorithm ◽  
Destination Point

This paper focuses on the robot trajectory planning algorithm in-depth study, we propose a new path planning algorithm to ensure that the velocity and the acceleration of the starting point and the destination point are zero at the same time, and there are continuity of the intermediate points also.Give the matlab simulation waveform diagram and the algorithm at last,and this trajectory planning provides a good reference value for robot trajectory studies of future.

Reaction couples of ceramic thin films prepared by CVD

1988 ◽  
Vol 46 ◽  
pp. 798-799
Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Solid State Reactions ◽  
Spatial Distributions ◽  
Diffusion Couples ◽  
Kinetics Studies ◽  
Ceramic Thin Films ◽  
Initial Stage

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.

Observations on the growth of barium bismuth oxide thin films

1992 ◽  
Vol 50 (1) ◽  
pp. 76-77
Author(s):  
M G. Norton ◽  
E.S. Hellman ◽  
E.H. Hartford ◽  
C.B. Carter
Keyword(s):  
Substrate Temperature ◽  
Deposition Process ◽  
Nucleation Layer ◽  
Second Stage ◽  
Device Applications ◽  
High Transition ◽  
Substrate Temperatures ◽  
Oriented Material ◽  
Barium Bismuth ◽  
Superconductor Device

The bismuthates (for example, Ba1-xKxBiO3) represent a class of high transition temperature superconductors. The lack of anisotropy and the long coherence length of the bismuthates makes them technologically interesting for superconductor device applications. To obtain (100) oriented Ba1-xKxBiO3 films on (100) oriented MgO, a two-stage deposition process is utilized. In the first stage the films are nucleated at higher substrate temperatures, without the potassium. This process appears to facilitate the formation of the perovskite (100) orientation on (100) MgO. This nucleation layer is typically between 10 and 50 nm thick. In the second stage, the substrate temperature is reduced and the Ba1-xKxBiO3 is grown. Continued growth of (100) oriented material is possible at the lower substrate temperature.

Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

1990 ◽  
Vol 48 (4) ◽  
pp. 6-7
Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Multilayer Structures ◽  
Rf Power ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Single Target ◽  
Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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