Bromeliad Sampling: A Passive Technique for Arboreal Amphibians across Ecosystems in the Neotropics

2021 ◽  
Vol 109 (1) ◽  
Author(s):  
Yonatan Aguilar-Cruz ◽  
María de los Ángeles Arenas-Cruz ◽  
Leticia M. Ochoa-Ochoa ◽  
Gerhard Zotz
Keyword(s):  
Passive Technique

The Measurements of Natural Radioactivity, (Radon and Gamma concentrations), around the old fertilizer factory in Basrah/Iraq

2015 ◽  
Vol 7 (1) ◽  
pp. 1324-1335
Author(s):  
Jabbar H. Jebur
Keyword(s):  
Effective Dose ◽  
Radon Concentration ◽  
Gamma Ray ◽  
Annual Effective Dose ◽  
Track Detector ◽  
Exhalation Rate ◽  
Hazard Indices ◽  
Radium Equivalent ◽  
Passive Technique ◽  
Radium Activity

Radon concentration, exhalation rate, annual effective dose, radium activity, thorium, uranium potassium and radium equivalent have been measured in the present investigation for soil in the area around the old fertilizer factory in southern of Basrah Governorate. The measurements based on CR39 track detector for passive method, RAD7 for active method and NaI(Tl) for gamma concentration measurements. Average values for radon concentration in soil were 112.04±10.76 Bq/m3 using passive technique and 104.56±6.05 Bq/m3 using RAD7. From the result of the passive technique, area and mass exhalation rates and the annual effective dose were calculated. Gamma ray spectroscopy for the soil samples were performed and found that the average concentrations of 226Ra, 232Th and 40K were 50.89 Bq/kg, 21.74 Bq/kg and 640.4 Bq/kg respectively. Gamma ray hazard indices were calculated and found they are within the world average.

Cusping, capture, and breakup of interacting drops by a curvatureless boundary-integral algorithm

1999 ◽  
Vol 391 ◽  
pp. 249-292 ◽  
Author(s):  
ALEXANDER Z. ZINCHENKO ◽  
MICHAEL A. ROTHER ◽  
ROBERT H. DAVIS
Keyword(s):  
Three Dimensional ◽  
Adaptive Mesh ◽  
Boundary Integral ◽  
Small Surface ◽  
Low Viscosity ◽  
Primary Breakup ◽  
Dimensional Boundary ◽  
Normal Vectors ◽  
Passive Technique ◽  
Line Singularities

A three-dimensional boundary-integral algorithm for interacting deformable drops in Stokes flow is developed. The algorithm is applicable to very large deformations and extreme cases, including cusped interfaces and drops closely approaching breakup. A new, curvatureless boundary-integral formulation is used, containing only the normal vectors, which are usually much less sensitive than is the curvature to discretization errors. A proper regularization makes the method applicable to small surface separations and arbitrary λ, where λ is the ratio of the viscosities of the drop and medium. The curvatureless form eliminates the difficulty with the concentrated capillary force inherent in two-dimensional cusps and allows simulation of three-dimensional drop/bubble motions with point and line singularities, while the conventional form can only handle point singularities. A combination of the curvatureless form and a special, passive technique for adaptive mesh stabilization allows three-dimensional simulations for high aspect ratio drops closely approaching breakup, using highly stretched triangulations with fixed topology. The code is applied to study relative motion of two bubbles or drops under gravity for moderately high Bond numbers [Bscr ], when cusping and breakup are typical. The deformation-induced capture efficiency of bubbles and low-viscosity drops is calculated and found to be in reasonable agreement with available experiments of Manga & Stone (1993, 1995b). Three-dimensional breakup of the smaller drop due to the interaction with a larger one for λ=O(1) is also considered, and the algorithm is shown to accurately simulate both the primary breakup moment and the volume partition by extrapolation for moderately supercritical conditions. Calculations of the breakup efficiency suggest that breakup due to interactions is significant in a sedimenting emulsion with narrow size distribution at λ=O(1) and [Bscr ][ges ]5–10. A combined capture and breakup phenomenon, when the smaller drop starts breaking without being released from the dimple formed on the larger one, is also observed in the simulations. A general classification of possible modes of two-drop interactions for λ=O(1) is made.

A Passive Technique to Monitor Evaporation Duct Height Using Coastal GNSS-R

2011 ◽  
Vol 8 (4) ◽  
pp. 587-591 ◽  
Author(s):  
Bo Wang ◽  
Zhen-Sen Wu ◽  
Zhen-Wei Zhao ◽  
Hong-Guang Wang
Keyword(s):  
Evaporation Duct ◽  
Passive Technique ◽  
Evaporation Duct Height

Passive Isolation by Nonlinear Boundaries for Flexible Structures

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiao-Ye Mao ◽  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Vibration Isolation ◽  
Flexible Structures ◽  
Linear Structure ◽  
Response Prediction ◽  
Structural Vibration ◽  
Original Structure ◽  
Analytic Method ◽  
Stress Control ◽  
Passive Isolation ◽  
Passive Technique

A simple passive technique of vibration isolation for flexible structures by nonlinear boundaries is investigated, which to our best knowledge is the first study of its kind reported in the literature. The equations of the structure are derived with Hamilton’s principle. An iterative analytic method is investigated to improve the accuracy of the response prediction. The effect of nonlinear boundaries of the structure is studied compared with the linear structure. It is found that stronger nonlinearities in the boundary make the system more stable. Analytical and simulation results show that nonlinear boundaries can significantly reduce the vibration and stress of flexible structures. It is important to point out that with the help of nonlinear boundaries, structural vibration and stress control can be achieved without altering the original structure.

scholarly journals An Interface–Particle Interaction Approach for Evaluation of the Co-Encapsulation Efficiency of Cells in a Flow-Focusing Droplet Generator

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3774
Author(s):  
Mohammad Yaghoobi ◽  
Mohammad Said Saidi ◽  
Sepehr Ghadami ◽  
Navid Kashaninejad
Keyword(s):  
Point Of Care ◽  
Particle Interaction ◽  
Cell Encapsulation ◽  
Surface Tension Force ◽  
Extensive Literature ◽  
The Finite Element Method ◽  
Proposed Model ◽  
Highly Sensitive ◽  
Passive Technique ◽  
Interaction Approach

Droplet-based microfluidics offers significant advantages, such as high throughput and scalability, making platforms based on this technology ideal candidates for point-of-care (POC) testing and clinical diagnosis. However, the efficiency of co-encapsulation in droplets is suboptimal, limiting the applicability of such platforms for the biosensing applications. The homogeneity of the bioanalytes in the droplets is an unsolved problem. While there is extensive literature on the experimental setups and active methods used to increase the efficiency of such platforms, passive techniques have received less attention, and their fundamentals have not been fully explored. Here, we develop a novel passive technique for investigating cell encapsulation using the finite element method (FEM). The level set method was used to track the interfaces of forming droplets. The effects of walls and the droplet interfaces on relatively large cells were calculated to track them more accurately during encapsulation. The static surface tension force was used to account for the effects of the interfaces on cells. The results revealed that the pairing efficiency is highly sensitive to the standard deviation (SD) of the distance between the cells in the entrance channel. The pairing efficiency prediction error of our model differed by less than 5% from previous experiments. The proposed model can be used to evaluate the performance of droplet-based microfluidic devices to ensure higher precision for co-encapsulation of cells.

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