scholarly journals Microwave reflectometric systems and monitoring apparatus for diffused-sensing applications

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 202
Author(s):  
Andrea Cataldo ◽  
Egidio De Benedetto ◽  
Raissa Schiavoni ◽  
Annarita Tedesco ◽  
Antonio Masciullo ◽  
...  
Keyword(s):  
Large Scale ◽  
Experimental Validation ◽  
Measurement Accuracy ◽  
Low Cost ◽  
Time Domain Reflectometry ◽  
Distributed Sensing ◽  
Building Structures ◽  
Sensing Element ◽  
Sensing Applications ◽  
Adequate Measurement

<p class="Abstract">Most sensing networks rely on punctual/local sensors; they thus lack the ability to spatially resolve the quantity to be monitored (e.g. a temperature or humidity profile) without relying on the deployment of numerous inline sensors. Currently, most quasi-distributed or distributed sensing technologies rely on the use of optical fibre systems. However, these are generally expensive, which limits their large-scale adoption. Recently, elongated sensing elements have been successfully used with time-domain reflectometry (TDR) to implement diffused monitoring solutions. The advantage of TDR is that it is a relatively low-cost technology, with adequate measurement accuracy and the potential to be customised to suit the specific needs of different application contexts in the 4.0 era. Based on these considerations, this paper addresses the design, implementation and experimental validation of a novel generation of elongated sensing element networks, which can be permanently installed in the systems that need to be monitored and used for obtaining the diffused profile of the quantity to be monitored. Three applications are considered as case studies: monitoring the irrigation process in agriculture, leak detection in underground pipes and the monitoring of building structures.</p>

Printing polyaniline for sensor applications

2013 ◽  
Vol 67 (8) ◽  
Author(s):  
Karl Crowley ◽  
Malcolm Smyth ◽  
Anthony Killard ◽  
Aoife Morrin
Keyword(s):  
Conducting Polymer ◽  
Inkjet Printing ◽  
Large Scale ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Scale Production ◽  
Light Emitting ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Large Scale Production

AbstractIn recent years, much research has focused on the development of low-cost, printed electrochemical sensor platforms for environmental monitoring and clinical diagnostics. Much effort in this area has been based on utilising the redox properties of conducting polymers, particularly polyaniline (PANI). In tackling the inherent lack of processability exhibited by these materials, several groups have examined various mass-amenable fabrication approaches to obtain suitable thin films of PANI for sensing applications. Specifically, the approaches investigated over the years include the in situ chemical synthesis of PANI, the use of sulphonated derivatives of PANI and the synthesis of aqueousbased nano-dispersions of PANI. Nano-dispersions have shown a great deal of promise for sensing applications, given that they are inkjet-printable, facilitating the patterning of conducting polymer directly to the substrate. We have shown that inkjet-printed films of PANI can be finely controlled in terms of their two-dimensional pattern, thickness, and conductivity, highlighting the level of precision achievable by inkjet printing. Utilising these nanomaterials as inkjet-printable inks opens novel, facile, and economical possibilities for conducting polymer-printed electronic applications in areas of sensing, but also many other application areas such as energy storage, displays, organic light-emitting diodes. Given that inkjet-printing is a scalable manufacturing technique, it renders possible the large-scale production of devices such as sensors for a range of applications. Several successes have emerged from our work and from the work of others in the area of applying PANI in low-cost sensor applications, which is the focus of this review.

scholarly journals Low-Cost, Disposable, Flexible and Highly Reproducible Screen Printed SERS Substrates for the Detection of Various Chemicals

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Wei Wu ◽  
Li Liu ◽  
Zhigao Dai ◽  
Juhua Liu ◽  
Shuanglei Yang ◽  
...  
Keyword(s):  
Screen Printing ◽  
Large Scale ◽  
Low Cost ◽  
Large Area ◽  
Sers Substrates ◽  
Sensing Applications ◽  
Relative Standard ◽  
Sers Detection ◽  
On Line ◽  
Liquid Milk

Abstract Ideal SERS substrates for sensing applications should exhibit strong signal enhancement, generate a reproducible and uniform response and should be able to fabricate in large-scale and low-cost. Herein, we demonstrate low-cost, highly sensitive, disposable and reproducible SERS substrates by means of screen printing Ag nanoparticles (NPs) on a plastic PET (Polyethylene terephthalate) substrates. While there are many complex methods for the fabrication of SERS substrates, screen printing is suitable for large-area fabrication and overcomes the uneven radial distribution. Using as-printed Ag substrates as the SERS platform, detection of various commonly known chemicals have been done. The SERS detection limit of Rhodamine 6G (R6G) is higher than the concentration of 1 × 10−10 M. The relative standard deviation (RSD) value for 784 points on the detection of R6G and Malachite green (MG) is less than 20% revealing a homogeneous SERS distribution and high reproducibility. Moreover, melamine (MA) is detected in fresh liquid-milk without additional pretreatment, which may accelerate the application of rapid on-line detection of MA in liquid milk. Our screen printing method highlights the use of large-scale printing strategies for the fabrication of well-defined functional nanostructures with applications well beyond the field of SERS sensing.

scholarly journals Security analysis of mobile crowd sensing applications

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nsikak P. Owoh ◽  
M. Mahinderjit Singh
Keyword(s):  
Information Disclosure ◽  
Large Scale ◽  
Low Cost ◽  
Security Analysis ◽  
Sensor Data ◽  
Sensitive Information ◽  
Security Scheme ◽  
Sensing Applications ◽  
Crowd Sensing ◽  
Encryption And Authentication

The proliferation of mobile phones with integrated sensors makes large scale sensing possible at low cost. During mobile sensing, data mostly contain sensitive information of users such as their real-time location. When such information are not effectively secured, users’ privacy can be violated due to eavesdropping and information disclosure. In this paper, we demonstrated the possibility of unauthorized access to location information of a user during sensing due to the ineffective security mechanisms in most sensing applications. We analyzed 40 apps downloaded from Google Play Store and results showed a 100% success rate in traffic interception and disclosure of sensitive information of users. As a countermeasure, a security scheme which ensures encryption and authentication of sensed data using Advanced Encryption Standard 256-Galois Counter Mode was proposed. End-to-end security of location and motion data from smartphone sensors are ensured using the proposed security scheme. Security analysis of the proposed scheme showed it to be effective in protecting Android based sensor data against eavesdropping, information disclosure and data modification.

Large-scale Production of Selective Gas Sensors Based on Carbon Nanotube Mats Transistors

2010 ◽  
Vol 1253 ◽  
Author(s):  
Louis Gorintin ◽  
Paolo Bondavalli ◽  
pierre legagneux ◽  
Marc Chatelet
Keyword(s):  
Gas Sensors ◽  
Large Scale ◽  
Gas Sensing ◽  
Field Effect Transistors ◽  
Low Cost ◽  
Flexible Substrates ◽  
Scale Production ◽  
Metal Electrodes ◽  
Sensing Applications ◽  
Large Scale Production

AbstractThe first paper showing the great potentiality of Carbon Nanotubes Field Effect transistors (CNTFETs) for gas sensing applications was published in 2000 [1]. It has been demonstrated that the performances of this kind of sensors are extremely interesting : a sensitivity of around 100ppt (e.g. for NO2 [2]) has been achieved in 2003 and several techniques to improve selectivity have been tested with very promising results [2]. The main issues that have not allowed, up to now, these devices to strike more largely the market of sensors, have been the lack of an industrial method to obtain low-cost devices, a demonstration of their selectivity in relevant environments and finally a deeper study on the effect of humidity and the possible solutions to reduce it. This contribution deals with CNTFETs based sensors fabricated using air-brush technique deposition on large surfaces. Compared to our last contribution [3], we have optimized the air-brush technique in order to obtain high performances transistors (Log(Ion)/ Log(Ioff) ~ 5/6) with highly reproducible characteristics : this is a key point for the industrial exploitation. We have developed a machine which allows us the dynamic deposition on heated substrates of the SWCNT solutions, improving dramatically the uniformity of the SWCNT mats. We have performed tests using different solvents that could be adapted as a function of the substrates (e.g. flexible substrates). Moreover these transistors have been achieved using different metal electrodes (patented approach [4]) in order to improve selectivity. Results of tests using NO2, NH3 with concentrations between ~ 1ppm and 10ppm will be shown during the meeting.

scholarly journals In Silico Comprehensive Study for Finding Potential Anti Biofilm Inhibiting Phyto-Chemical by Homology Modeling, Virtual Screening, Docking and Molecular Dynamics Simulation

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Ashutosh Nayak
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Biofilm Formation ◽  
Large Scale ◽  
Experimental Validation ◽  
Low Cost ◽  
Dynamics Simulation ◽  
Essential Requirement ◽  
Self Defense ◽  
Comprehensive Study

Biofilm is an essential requirement of microbes for its propagation and it helps in self-defense against antibiotics and adverse environmental factors. But a boon for bacteria has unfavorable economic and health implications on humans. The sheer scale of biofilm formation makes it very difficult for a prepared industrial inhibitor to be economically feasible. This is where Phyto-chemicals can be used as a potential inhibitor because of its low cost of production and easy availability to be used on such a large scale. In this study, we aim to find a potential Phyto-chemical ligand for a Cellulose synthesizing protein BcsF for Salmonella typhimurium (strain LT2 / SGSC1412) which is one of the leading species of microbe that responsible for a biofilm-forming matrix. By screening antibacterial Phyto-chemical against our protein, we found that Procyanidin (Pubchem id 124017) had the least binding energy, which can be taken as a probable anti-biofilm agent for experimental validation.

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.

Electronic Package Failure Analysis Using TDR

2000 ◽  
Author(s):  
Dima A. Smolyansky
Keyword(s):  
Failure Analysis ◽  
Fault Location ◽  
Measurement Accuracy ◽  
Time Domain Reflectometry ◽  
Acoustic Imaging ◽  
X Ray ◽  
Analysis Techniques ◽  
Bga Packages ◽  
Impedance Profile ◽  
Nature Of Time

Abstract The visual nature of Time Domain Reflectometry (TDR) makes it a very natural technology that can assist with fault location in BGA packages, which typically have complex interweaving layouts that make standard failure analysis techniques, such as acoustic imaging and X-ray, less effective and more difficult to utilize. This article discusses the use of TDR for package failure analysis work. It analyzes in detail the TDR impedance deconvolution algorithm as applicable to electronic packaging fault location work, focusing on the opportunities that impedance deconvolution and the resulting true impedance profile opens up for such work. The article examines the TDR measurement accuracy and the comparative package failure analysis, and presents three main considerations for package failure analysis. It also touches upon the goal and the task of the failure analysts and TDR's specific signatures for the open and short connections.

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

scholarly journals Rapid, large-scale species discovery in hyperdiverse taxa using 1D MinION sequencing

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Large Scale ◽  
Low Cost ◽  
Small Body ◽  
Small Subset ◽  
Similar Species ◽  
Large Species ◽  
Morphological Examination ◽  
Species Discovery ◽  
Short Period

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.

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