scholarly journals Ball pen writing-without-ink: a truly simple and accessible method for sensitivity enhancement in lateral flow assays

RSC Advances ◽  
2022 ◽  
Vol 12 (4) ◽  
pp. 2068-2073
Author(s):  
Zedong Li ◽  
Shuang Wu ◽  
Jingcheng Ji ◽  
Yuemeng Bai ◽  
Pengpeng Jia ◽  
...  

A ball pen writing-without-ink method was developed to amplify the detection signal of LFAs through controlling fluid flow rate.

2019 ◽  
Vol 11 (1) ◽  
pp. 01025-1-01025-5 ◽  
Author(s):  
N. A. Borodulya ◽  
◽  
R. O. Rezaev ◽  
S. G. Chistyakov ◽  
E. I. Smirnova ◽  
...  

1956 ◽  
Vol 23 (2) ◽  
pp. 269-272
Author(s):  
L. F. Welanetz

Abstract An analysis is made of the suction holding power of a device in which a fluid flows radially outward from a central hole between two parallel circular plates. The holding power and the fluid flow rate are determined as functions of the plate separation. The effect of changing the proportions of the device is investigated. Experiments were made to check the analysis.


2018 ◽  
Vol 12 (4) ◽  
pp. 294-300 ◽  
Author(s):  
Santhosh K. Venkata ◽  
Bhagya R. Navada

Abstract In this paper, implementation of soft sensing technique for measurement of fluid flow rate is reported. The objective of the paper is to design an estimator to physically measure the flow in pipe by analysing the vibration on the walls of the pipe. Commonly used head type flow meter causes obstruction to the flow and measurement would depend on the placement of these sensors. In the proposed technique vibration sensor is bonded on the pipe of liquid flow. It is observed that vibration in the pipe varies with the control action of stem. Single axis accelerometer is used to acquire vibration signal from pipe, signal is passed from the sensor to the system for processing. Basic techniques like filtering, amplification, and Fourier transform are used to process the signal. The obtained transform is trained using neural network algorithm to estimate the fluid flow rate. Artificial neural network is designed using back propagation with artificial bee colony algorithm. Designed estimator after being incorporated in practical setup is subjected to test and the result obtained shows successful estimation of flow rate with the root mean square percentage error of 0.667.


2021 ◽  
pp. 1-10
Author(s):  
Yongsheng Liu ◽  
Xing Qin ◽  
Yuchen Sun ◽  
Zijun Dou ◽  
Jiansong Zhang ◽  
...  

Abstract Aiming at the oscillation drag reduction tool that improves the extension limit of coiled tubing downhole operations, the fluid hammer equation of the oscillation drag reducer is established based on the fluid hammer effect. The fluid hammer equation is solved by the asymptotic method, and the distribution of fluid pressure and flow velocity in coiled tubing with oscillation drag reducers is obtained. At the same time, the axial force and radial force of the coiled tubing caused by the fluid hammer oscillator are calculated according to the momentum theorem. The radial force will change the normal contact force of the coiled tubing which has a great influence on frictional drag. The results show that the fluid flow rate and pressure decrease stepwise from the oscillator position to the wellhead position, and the fluid flow rate and pressure will change abruptly during each valve opening and closing time. When the fluid passes through the oscillator, the unit mass fluid will generate an instantaneous axial tension due to the change in the fluid velocity, thereby converting the static friction into dynamic friction, which is conducive to the extend limit of coiled tubing.


Author(s):  
Olutosin Olufisayo Ilori ◽  
Dare A. Adetan ◽  
Lasisi E. Umoru

The study determined the effect of cutting parameters on the surface residual stress of face-milled pearlitic ductile iron with a view to enhancing surface integrity of machined parts in the manufacturing industries. The pearlitic ductile iron used for this study was prepared and four cutting parameters were considered. The results obtained showed that the average surface residual stress of the machined surfaces was tensile and increased significantly with increase in depth of cut. Feed rate and cutting speed exhibited some effect, though not statistically significant, on average surface residual stress. The average residual stress was found to decrease significantly and drastically from 605.39 MPa to 101.72 MPa as cutting fluid flow rate increased from 0 ?/min to 4 ?/min. The study concluded that out of all four cutting parameters investigated, the cutting fluid flow rate has most considerable influence on the surface residual stress of the machined pearlitic ductile iron.


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 841 ◽  
Author(s):  
Reza Taherdangkoo ◽  
Alexandru Tatomir ◽  
Mohammad Taherdangkoo ◽  
Pengxiang Qiu ◽  
Martin Sauter

Hydraulic fracturing of horizontal wells is an essential technology for the exploitation of unconventional resources, but led to environmental concerns. Fracturing fluid upward migration from deep gas reservoirs along abandoned wells may pose contamination threats to shallow groundwater. This study describes the novel application of a nonlinear autoregressive (NAR) neural network to estimate fracturing fluid flow rate to shallow aquifers in the presence of an abandoned well. The NAR network is trained using the Levenberg–Marquardt (LM) and Bayesian Regularization (BR) algorithms and the results were compared to identify the optimal network architecture. For NAR-LM model, the coefficient of determination (R2) between measured and predicted values is 0.923 and the mean squared error (MSE) is 4.2 × 10−4, and the values of R2 = 0.944 and MSE = 2.4 × 10−4 were obtained for the NAR-BR model. The results indicate the robustness and compatibility of NAR-LM and NAR-BR models in predicting fracturing fluid flow rate to shallow aquifers. This study shows that NAR neural networks can be useful and hold considerable potential for assessing the groundwater impacts of unconventional gas development.


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