Measurement Model and Simulation of Soil Nitrate Nitrogen Based on Ion Selective Electrode

2013 ◽  
Vol 718-720 ◽  
pp. 657-662
Author(s):  
Li Zhang ◽  
Zhi Kai Chang ◽  
Shang Feng Du
Keyword(s):  
Mathematical Model ◽  
Nitrate Nitrogen ◽  
Low Cost ◽  
Measurement Model ◽  
Temperature Correction ◽  
Detection Methods ◽  
Soil Nitrate ◽  
Grass Roots ◽  
Measurement Models ◽  
Model And Simulation

The existing conventional detection methods ofnitrate nitrogenmostly consume time, cost a lot of moneyand need professionals. This limits the application of soil testing and fertilization technology at the grass-roots level. Therefore, a kind of fast, low-cost and simple operated method of soil nitrate nitrogen is in urgent need. The research of measurement models based on electrochemical principles of soil nitrate nitrogen is carried out in this paper to the issue ofquick access to the information of soil nitrate nitrogen. The linear regression equation is used to establish the mathematical model of electrodes and the binary quadratic regression model is used to study the temperature correction mathematical model of electrodes and finally matlab is used for datasimulation.

Evaluation of a Solid-State Electrode for the Rapid Detection of Soil Nitrate-Nitrogen

2011 ◽  
Vol 422 ◽  
pp. 96-101
Author(s):  
Miao Zhang ◽  
S. Simon Ang ◽  
Mao Hua Wang ◽  
Gang Liu
Keyword(s):  
Solid State ◽  
Nitrate Nitrogen ◽  
Low Cost ◽  
Simultaneous Detection ◽  
Fertilizer Application ◽  
Laboratory Evaluation ◽  
Soil Nitrate ◽  
Negative Drift ◽  
Fluidic Control

In recent years, the prolific usage of nitrogenous fertilizers in the agricultural area of China has resulted in inefficient nitrogen usage, environmental pollution and the degradation of the soil fertility. As such, a rapid, low-cost and reliable soil detection method is urgently needed. This study reported on the laboratory evaluation of a solid-state ion-selective electrode, based on a nitrate doped polypyrrole polymer (PPy(NO3-)), for the simultaneous detection of soil nitrate-nitrogen. The potentiometric slope of these PPy(NO3-) electrodes for nitrate was found to be -(53.3±0.8) mV/decade over a linear range of three decades of concentration 10-4～10-1mol/L. It was also found that these electrodes had a nitrate detection limit of 5.0 ×10-5 mol/L. Impacts of soil extractant conditions were also tested. The electrodes displayed better performances for nitrate solutions with pH lower than 7.0. The potentiometric responses of electrodes exhibited a negative drift tendency of 0.6 mV/°C, which was probably caused by changes of the polymer morphology and the solution ionic activity. In order to reduce the interferences of coexisting anion, deionized water was chosen as soil extractant. It is shown that a fast determination of soil nitrate levels for site-specific control of fertilizer application could be realized using the PPy(NO3-) electrodes together with an automatic fluidic control system.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals A Survey on Deep Learning Based Methods and Datasets for Monocular 3D Object Detection

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 517
Author(s):  
Seong-heum Kim ◽  
Youngbae Hwang
Keyword(s):  
Deep Learning ◽  
Object Detection ◽  
Low Cost ◽  
Detection Methods ◽  
Future Research ◽  
3D Object ◽  
Practical Applications ◽  
Depth Sensors ◽  
Significant Research ◽  
3D Object Detection

Owing to recent advancements in deep learning methods and relevant databases, it is becoming increasingly easier to recognize 3D objects using only RGB images from single viewpoints. This study investigates the major breakthroughs and current progress in deep learning-based monocular 3D object detection. For relatively low-cost data acquisition systems without depth sensors or cameras at multiple viewpoints, we first consider existing databases with 2D RGB photos and their relevant attributes. Based on this simple sensor modality for practical applications, deep learning-based monocular 3D object detection methods that overcome significant research challenges are categorized and summarized. We present the key concepts and detailed descriptions of representative single-stage and multiple-stage detection solutions. In addition, we discuss the effectiveness of the detection models on their baseline benchmarks. Finally, we explore several directions for future research on monocular 3D object detection.

scholarly journals Measuring the Refined Theory of Individual Values in 49 Cultural Groups: Psychometrics of the Revised Portrait Value Questionnaire

Assessment ◽  
2021 ◽  
pp. 107319112199876
Author(s):  
Shalom H. Schwartz ◽  
Jan Cieciuch
Keyword(s):  
Measurement Model ◽  
Scaling Analysis ◽  
Refined Theory ◽  
Cultural Groups ◽  
Individual Values ◽  
Internal Reliability ◽  
Measurement Models ◽  
Circular Structure ◽  
Almost All ◽  
Portrait Value Questionnaire

Researchers around the world are applying the recently revised Portrait Value Questionnaire (PVQ-RR) to measure the 19 values in Schwartz’s refined values theory. We assessed the internal reliability, circular structure, measurement model, and measurement invariance of values measured by this questionnaire across 49 cultural groups ( N = 53,472) and 32 language versions. The PVQ-RR reliably measured 15 of the 19 values in the vast majority of groups and two others in most groups. The fit of the theory-based measurement models supported the differentiation of almost all values in every cultural group. Almost all values were measured invariantly across groups at the configural and metric level. A multidimensional scaling analysis revealed that the PVQ-RR perfectly reproduced the theorized order of the 19 values around the circle across groups. The current study established the PVQ-RR as a sound instrument to measure and to compare the hierarchies and correlates of values across cultures.

scholarly journals Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4916 ◽  
Author(s):  
Qiaoyun Wu ◽  
Yunzhe Zhang ◽  
Qian Yang ◽  
Ning Yuan ◽  
Wei Zhang
Keyword(s):  
Pathogen Detection ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Ease Of Use ◽  
Detection Methods ◽  
Future Research ◽  
Dna Biosensors ◽  
Food Borne Pathogens ◽  
Chip Technology ◽  
Food Borne

The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).

Fallow management, soil water, plant-available soil nitrogen and grain sorghum production in south west Queensland

1992 ◽  
Vol 32 (4) ◽  
pp. 473 ◽  
Author(s):  
G Gibson ◽  
BJ Radford ◽  
RGH Nielsen
Keyword(s):  
Soil Water ◽  
Nitrate Nitrogen ◽  
Soil Nitrate ◽  
Zero Tillage ◽  
Fallow Management ◽  
South West ◽  
Primary Tillage ◽  
Grain Nitrogen ◽  
Texture Contrast ◽  
Gypsum Application

The effects of tillage frequency (conventional, reduced and zero), primary tillage implement (disc, blade and chisel plough), stubble management (retention and removal), gypsum application, and paraplowing were examined with respect to soil water storage, soil nitrate accumulation, crop establishment, crop growth, grain yield and grain nitrogen content for 4 successive sorghum crops on a sodic, texture-contrast soil in south west Queensland. Retention of sorghum stubble (v. removal) produced an increase in mean yield of sorghum grain of 393 kg/ha, due to increased soil water extraction and increased water use efficiency by the following crop. The highest mean yield occurred after reduced blade tillage with stubble retained. Zero tillage with stubble removed gave the lowest mean grain yield. Zero tillage always had the lowest quantity of soil nitrate-nitrogen at sowing. In one fallow, increased aggressiveness of primary tillage (disc v. blade plough) increased the quantity of nitrate-nitrogen in the top 60 cm of soil at sowing. These effects on available soil nitrogen did not result in corresponding differences in grain nitrogen content. Results indicate that for optimum fallow management on this texture-contrast soil in south west Queensland, sorghum residues should be retained, tillage frequency should be reduced, but not to zero, blade ploughing should be preferred to discing, and gypsum application should not be practised.

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