scholarly journals Simulation and performance analysis of Multiple PCS sensors system

2017 ◽  
Vol 20 (2) ◽  
pp. 85
Author(s):  
Pawan Whig ◽  
Syed Naseem Ahmad ◽  
Surinder Kumar

In this paper, a novel circuit is presented which overcome a serious limitation found in case of multiple sensors system. In this novel system design only one reference electrode and few active components used that makes the implementation of a low-cost system for the supervision of water quality. Photo Catalytic Sensor (PCS) estimates the parameter BOD (Biological Oxygen Demand) which is generally used to estimate quality of water. The system proposed in this paper involves a balanced bridge approach using few electronic components that provides a correlation in the input-output signals of low-cost sensors. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans conductance gain. The trans-conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O2 in the solution.

2014 ◽  
Vol 23 (06) ◽  
pp. 1450079 ◽  
Author(s):  
PAWAN WHIG ◽  
SYED NASEEM AHMAD

In this paper, the design of an ASIC is presented that implement a low-cost system for the supervision of water quality in urban areas or rivers. Photo catalytic sensor (PCS) estimates the parameter biological oxygen demand (BOD) which is generally used to estimate quality of water. The system proposed in this paper involves a simple potentiometric approach that provides a correlation in the input–output signals of low-cost sensors. This approach which is more users friendly and fast in operation is obtained by modeling and optimization of sensor for water quality monitoring. This is to overcome several drawbacks generally found in the previous flow injection analysis method of determining chemical oxygen demand (COD)-like complex designing, nonlinearity and long computation time. The system constitutes a significant cost reduction in the supervision of water quality monitoring. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O 2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans-conductance gain. The trans-conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O 2 in the solution. In this design simple potentiometric approach with few passive components are used to build a readout circuit. The paper focuses on the electronic implementation of the readout system for the PCS which optimize the circuit performance and increases reliability.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 480 ◽  
Author(s):  
Mario Prosa ◽  
Margherita Bolognesi ◽  
Lucia Fornasari ◽  
Gerardo Grasso ◽  
Laura Lopez-Sanchez ◽  
...  

In the last decade, biochemical sensors have brought a disruptive breakthrough in analytical chemistry and microbiology due the advent of technologically advanced systems conceived to respond to specific applications. From the design of a multitude of different detection modalities, several classes of sensor have been developed over the years. However, to date they have been hardly used in point-of-care or in-field applications, where cost and portability are of primary concern. In the present review we report on the use of nanostructured organic and hybrid compounds in optoelectronic, electrochemical and plasmonic components as constituting elements of miniaturized and easy-to-integrate biochemical sensors. We show how the targeted design, synthesis and nanostructuring of organic and hybrid materials have enabled enormous progress not only in terms of modulation and optimization of the sensor capabilities and performance when used as active materials, but also in the architecture of the detection schemes when used as structural/packing components. With a particular focus on optoelectronic, chemical and plasmonic components for sensing, we highlight that the new concept of having highly-integrated architectures through a system-engineering approach may enable the full expression of the potential of the sensing systems in real-setting applications in terms of fast-response, high sensitivity and multiplexity at low-cost and ease of portability.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.


2020 ◽  
Vol 16 (3) ◽  
pp. 341-348
Author(s):  
Surinya Traipop ◽  
Suchada Chuanuwatanakul ◽  
Orawon Chailapakul ◽  
Eakkasit Punrat

Background: Recently, Derris scandens, a Thai herbal medicine with anti-inflammatory activity, is widely used as beverage and supplementary food. When the traditional medicine is a choice for health therapy, the simple and reliable equipment is required to control the suitable consuming amount of the active component. Objective: To develop the electrochemical sensor for genistein determination in Derris scandens with high sensitivity and rapid operation. Methods: An in-house screen-printed electrochemical sensor consisting of a three-electrode system was developed for genistein determination. A silver/silver chloride (Ag/AgCl) reference electrode, a carbon counter electrode and a carbon working electrode were prepared on a 0.3-mm-thick plastic substrate by the screen-printing technique using conductive ink. The dimensions of each sensor were 2.5×1.0 cm. Only 50 µL of sample solution was required on this device for the determination of genistein concentration by rapid response square wave voltammetry. Results: The oxidation peak of genistein appeared with good response in acidic media at a peak potential of 0.6 V. Moreover, the signal was enhanced by modifying the conductive carbon ink with cobalt( II) phthalocyanine. Under the optimized conditions, the linear range was found to be 2.5-150 µM and the detection limit was 1.5 µM. Moreover, the small volume extraction was successfully developed without any further pre-concentration. This proposed method was applied to determine genistein in Derris scandens with satisfying results. Conclusion: The proposed method is promising as an alternative method for genistein determination with facile and fast analysis.


Author(s):  
José Capmany ◽  
Daniel Pérez

Programmable Integrated Photonics (PIP) is a new paradigm that aims at designing common integrated optical hardware configurations, which by suitable programming can implement a variety of functionalities that, in turn, can be exploited as basic operations in many application fields. Programmability enables by means of external control signals both chip reconfiguration for multifunction operation as well as chip stabilization against non-ideal operation due to fluctuations in environmental conditions and fabrication errors. Programming also allows activating parts of the chip, which are not essential for the implementation of a given functionality but can be of help in reducing noise levels through the diversion of undesired reflections. After some years where the Application Specific Photonic Integrated Circuit (ASPIC) paradigm has completely dominated the field of integrated optics, there is an increasing interest in PIP justified by the surge of a number of emerging applications that are and will be calling for true flexibility, reconfigurability as well as low-cost, compact and low-power consuming devices. This book aims to provide a comprehensive introduction to this emergent field covering aspects that range from the basic aspects of technologies and building photonic component blocks to the design alternatives and principles of complex programmable photonics circuits, their limiting factors, techniques for characterization and performance monitoring/control and their salient applications both in the classical as well as in the quantum information fields. The book concentrates and focuses mainly on the distinctive features of programmable photonics as compared to more traditional ASPIC approaches.


2013 ◽  
Vol 726-731 ◽  
pp. 2521-2525
Author(s):  
Zhi Yong Zhang ◽  
De Li Wu

Coking wastewater is a kind of recalcitrant wastewater including complicate compositions. Advanced treatment of coking wastewater by Fenton-Like reaction using pyrite as catalyst was investigated in this paper. The results show that the chemical oxygen demand (COD) of coking wastewater decreased significantly by method of coagulation combined with two-stage oxidation reaction. COD of wastewater can decrease from 250mg/l to 45mg/l after treatment, when 2g/L pyrite was used in each stage oxidation and the dosage of hydrogen peroxide (H2O2) is 0.2ml/l for first stage treatment, 0.1ml/l for second stage treatment respectively. The pyrite is effective to promote Fenton-Like reaction with low cost due to high utilization efficiency of H2O2, moreover, catalyst could be easily recovered and reused. The Fenton-Like reaction might be used as a potential alternative to advanced treatment of recalcitrant wastewater.


1987 ◽  
Vol 14 (3) ◽  
pp. 134-140 ◽  
Author(s):  
K.A. Clarke

Practical classes in neurophysiology reinforce and complement the theoretical background in a number of ways, including demonstration of concepts, practice in planning and performance of experiments, and the production and maintenance of viable neural preparations. The balance of teaching objectives will depend upon the particular group of students involved. A technique is described which allows the embedding of real compound action potentials from one of the most basic introductory neurophysiology experiments—frog sciatic nerve, into interactive programs for student use. These retain all the elements of the “real experiment” in terms of appearance, presentation, experimental management and measurement by the student. Laboratory reports by the students show that the experiments are carefully and enthusiastically performed and the material is well absorbed. Three groups of student derive most benefit from their use. First, students whose future careers will not involve animal experiments do not spend time developing dissecting skills they will not use, but more time fulfilling the other teaching objectives. Second, relatively inexperienced students, struggling to produce viable neural material and master complicated laboratory equipment, who are often left with little time or motivation to take accurate readings or ponder upon neurophysiological concepts. Third, students in institutions where neurophysiology is taught with difficulty because of the high cost of equipment and lack of specific expertise, may well have access to a low cost general purpose microcomputer system.


2021 ◽  
Vol 11 (6) ◽  
pp. 2535
Author(s):  
Bruno E. Silva ◽  
Ramiro S. Barbosa

In this article, we designed and implemented neural controllers to control a nonlinear and unstable magnetic levitation system composed of an electromagnet and a magnetic disk. The objective was to evaluate the implementation and performance of neural control algorithms in a low-cost hardware. In a first phase, we designed two classical controllers with the objective to provide the training data for the neural controllers. After, we identified several neural models of the levitation system using Nonlinear AutoRegressive eXogenous (NARX)-type neural networks that were used to emulate the forward dynamics of the system. Finally, we designed and implemented three neural control structures: the inverse controller, the internal model controller, and the model reference controller for the control of the levitation system. The neural controllers were tested on a low-cost Arduino control platform through MATLAB/Simulink. The experimental results proved the good performance of the neural controllers.


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