scholarly journals Biosensing Near the Exceptional Point Based on Resonant Optical Tunneling Effect

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 426
Author(s):  
Yang Liu ◽  
Pengyun Yan ◽  
Feng Liu ◽  
Aoqun Jian ◽  
Shengbo Sang

Inspired by exceptional point (EP) sensing in non-Hermitian systems, in this work, a label-free biosensor for detecting low-concentration analytes is proposed, via a special multilayer structure: a resonant optical tunneling resonator. Due to the square root topology near the exceptional point, a recognized target analyte perturbs the system deviated from the exceptional point, leading to resolvable modes splitting in the transmission spectrum. The performance of the designed sensor is analyzed by the coupled-mode theory and transfer matrix method, separately. Here, the simulation results demonstrate that the obtained sensitivity is 17,120 nm/imaginary part unit of refractive index (IP) and the theoretical detection limit is 4.2 × 10−8 IP (regarding carcinoembryonic antigen (CEA), the minimum detection value is 1.78 ng). Instead of the typical diffusion manner, the liquid sample is loaded by convection, which can considerably improve the efficiency of sample capture and shorten the response time of the sensor. The sketched sensor may find potential application in the fields of biomedical detection, environment protection, and drinking water safety.

2013 ◽  
Vol 361-363 ◽  
pp. 674-681
Author(s):  
Wei Li

As more and more non-public fund entering rural drinking water safety engineering project market; it becomes very necessary to built rural drinking water safety engineering project guarantee mechanism. This paper proposes three steps of mechanism design. Firstly, history data is used to fit multivariate linear equation set up describing relationship between bank loss and key risk factors. Secondly, guarantee fee is calculated through model regression, which is threefold of possible bank loss. Thirdly, guarantee fee is adjusted according to variety of key risk factor in the process of project construction and operating.


2013 ◽  
Vol 49 (1) ◽  
pp. 5-9 ◽  
Author(s):  
D. C. Reid ◽  
K. Abramowski ◽  
A. Beier ◽  
A. Janzen ◽  
D. Lok ◽  
...  

Traditionally, the regulatory approach to maintaining the quality and safety of drinking water has largely been a prescriptive one based on the ability of any given supply to meet standards set for a number of different chemical and biological parameters. There are a number of issues around the assumptions and the limitations of a sampling and analysis regime. The basis for such regimes is essentially reactive rather than proactive and, consequently, the cause of the concern may already have impacted consumers before any effective action can be taken. Environment and Sustainable Resource Development has developed a template for recording drinking water safety plans together with guidance notes to help complete them. The template has been developed in MS-Excel and has been designed in a straightforward step-wise manner with guidance on the completion of each sheet. It includes four main risk tables covering each main element of water supply which are pre-populated with commonly found ‘generic’ risks and these are carefully assessed before considering what action is required to deal with significant risks. Following completion of the risk tables, key risks are identified and the interventions required to bring them into control.


Crystals ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 113 ◽  
Author(s):  
Ivan V. Timofeev ◽  
Pavel S. Pankin ◽  
Stepan Ya. Vetrov ◽  
Vasily G. Arkhipkin ◽  
Wei Lee ◽  
...  

Author(s):  
F. Craciun ◽  
L. Sorba ◽  
E. Molinari ◽  
M. Pappalardo

2003 ◽  
Vol 47 (3) ◽  
pp. 7-14 ◽  
Author(s):  
S.E. Hrudey ◽  
P. Payment ◽  
P.M. Huck ◽  
R.W. Gillham ◽  
E.J. Hrudey

An estimated 2,300 people became seriously ill and seven died from exposure to microbially contaminated drinking water in the town of Walkerton, Ontario, Canada in May 2000. The severity of this drinking water disaster resulted in the Government of Ontario calling a public inquiry by Mr. Justice Dennis O’Connor to address the cause of the outbreak, the role (if any) of government policies in contributing to this outbreak and, ultimately, the implications of this experience on the safety of drinking water across the Province of Ontario. The circumstances surrounding the Walkerton tragedy are an important reference source for those concerned with providing safe drinking water. Although some circumstances are obviously specific to this epidemic, others are uncomfortably reminiscent of waterborne outbreaks that have occurred elsewhere. These recurring themes suggested the need for attention to broad issues of drinking water security and they present the challenge for how drinking water safety can be managed to prevent such tragedies in the future.


2019 ◽  
Vol 654 ◽  
pp. 1132-1145 ◽  
Author(s):  
Lucas Rocha-Melogno ◽  
Rebecca Yoo ◽  
Osvaldo Broesicke ◽  
Achilles Kallergis ◽  
José Garcia ◽  
...  

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