scholarly journals Long-term reliability of the Figaro TGS 2600 solid-state methane sensor under low Arctic conditions at Toolik lake, Alaska

2019 ◽  
Author(s):  
Werner Eugster ◽  
James Laundre ◽  
Jon Eugster ◽  
George W. Kling
Keyword(s):  
Solid State ◽  
Low Cost ◽  
Full Range ◽  
Absolute Humidity ◽  
Diel Cycles ◽  
Arctic Conditions ◽  
Sensor Signals ◽  
Ch4 Concentration ◽  
Reference Measurements

Abstract. The TGS 2600 was the first low-cost solid state sensor that shows a weak response to ambient levels of CH4 (e.g., range ≈1.8–2.7 ppm). Here we present an empirical function to correct the TGS 2600 signal for temperature and (absolute) humidity effects and address the long-term reliability of two identical sensors deployed from 2012 to 2018. We assess the performance of the sensors at 30-minute resolution and aggregated to weekly medians. Over the entire period the agreement between TGS-derived and reference CH4 concentrations measured by a high-precision Los Gatos Research instrument was R2 = 0.42, with better results during summer (R2 = 0.65 in summer 2012). Using absolute instead of relative humidity for the correction of the TGS 2600 sensor signals reduced the typical deviation from the reference to less than ±0.1 ppm over the full range of temperatures from −41 °C to 27 °C. At weekly resolution the two sensors showed a downward drift of signal voltages indicating that after 10–13 years a TGS 2600 may have reached its end of life. While the true trend in CH4 concentrations measured by the high-quality reference instrument was 10.1 ppb yr−1 (2012–2018), part of the downward trend in sensor signal (ca. 40–60 %) may be due to the increase in CH4 concentration, because the sensor voltage decreases with increasing CH4 concentration. Weekly median diel cycles tend to agree surprisingly well between the TGS 2600 and reference measurements during the snow-free season, but in winter the agreement is lower. We suggest developing separate functions for deducing CH4 concentrations from TGS 2600 measurements under cold and warm conditions. We conclude that the TGS 2600 sensor can provide data of research-grade quality if it is adequately calibrated and placed in a suitable environment where cross-sensitivities to gases other than CH4 is of no concern.

scholarly journals Long-term reliability of the Figaro TGS 2600 solid-state methane sensor under low-Arctic conditions at Toolik Lake, Alaska

2020 ◽  
Vol 13 (5) ◽  
pp. 2681-2695 ◽  
Author(s):  
Werner Eugster ◽  
James Laundre ◽  
Jon Eugster ◽  
George W. Kling
Keyword(s):  
Solid State ◽  
Mole Fraction ◽  
Low Cost ◽  
Full Range ◽  
Absolute Humidity ◽  
Diel Cycles ◽  
Arctic Conditions ◽  
Sensor Signals ◽  
Reference Measurements

Abstract. The TGS 2600 was the first low-cost solid-state sensor that shows a response to ambient levels of CH4 (e.g., range ≈1.8–2.7 µmol mol−1). Here we present an empirical function to correct the TGS 2600 signal for temperature and (absolute) humidity effects and address the long-term reliability of two identical sensors deployed from 2012 to 2018. We assess the performance of the sensors at 30 min resolution and aggregated to weekly medians. Over the entire period the agreement between TGS-derived and reference CH4 mole fractions measured by a high-precision Los Gatos Research instrument was R2=0.42, with better results during summer (R2=0.65 in summer 2012). Using absolute instead of relative humidity for the correction of the TGS 2600 sensor signals reduced the typical deviation from the reference to less than ±0.1 µmol mol−1 over the full range of temperatures from −41 to 27 ∘C. At weekly resolution the two sensors showed a downward drift of signal voltages indicating that after 10–13 years a TGS 2600 may have reached its end of life. While the true trend in CH4 mole fractions measured by the high-quality reference instrument was 10.1 nmolmol-1yr-1 (2012–2018), part of the downward trend in sensor signal (ca. 40 %–60 %) may be due to the increase in CH4 mole fraction because the sensor voltage decreases with increasing CH4 mole fraction. Weekly median diel cycles tend to agree surprisingly well between the TGS 2600 and reference measurements during the snow-free season, but in winter the agreement is lower. We suggest developing separate functions for deducing CH4 mole fractions from TGS 2600 measurements under cold and warm conditions. We conclude that the TGS 2600 sensor can provide data of research-grade quality if it is adequately calibrated and placed in a suitable environment where cross-sensitivities to gases other than CH4 are of no concern.

scholarly journals Field Setup and Assessment of a Cloud-Data Based Crane Scale (CCS) Considering Weight- and Local Green Wood Density-Related Volume References

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Michael Starke ◽  
Chris Geiger
Keyword(s):  
Low Cost ◽  
Reference Value ◽  
Observation Time ◽  
Hydraulic Pressure ◽  
Acceptable Error ◽  
Cloud Data ◽  
Starting Point ◽  
Crane Scale ◽  
Reference Measurements

When investigating the forwarding process within the timber supply chain, insufficient data often inhibits long-term studies or make real-time optimisation of the logistics process difficult. Information sources to compensate for this lack of data either depend on other processing steps or they need additional, costly hardware, such as conventional crane scales. An innovative weight-detection concept using information provided by a commonly available hydraulic pressure sensor may make the introduction of a low-cost weight information system possible. In this system, load weight is estimated by an artificial neural network (ANN) based on machine data such as the hydraulic pressure of the inner boom cylinder and the grapple position.In our study, this type of crane scale was set up and tested under real working conditions, implemented as a cloud application. The weight scale ANN algorithm was therefore modified for robustness and executed on data collected with a commonly available telematics module. To evaluate the system, also with regard to larger sample sizes, both direct weight-reference measurements and additional volume-reference measurements were made. For the second, locally valid weight-volume conversion factors for mainly Norway spruce (Picea abies, 906 kg m-3, standard error of means (SEM) of 13.6 kg m-3), including mean density change over the observation time (–0.16% per day), were determined and used as supportive weight-to-volume conversion factor.Although the accuracy of the weight scale was lower than in previous laboratory tests, the system showed acceptable error behaviour for different observation purposes. The twice-observed SEM of 1.5% for the single loading movements (n=95, root-mean-square error (RMSE) of 15.3% for direct weight reference; n=440, RMSE=33.2% for volume reference) enables long-term observations considering the average value, but the high RMSE reveals problems with regard to the single value information.The full forwarder load accuracy, as unit of interest, was observed with an RMSE of 10.6% (n=41), considering a calculated weight-volume conversion as reference value. An SEM of 5.1% for already five observations with direct weight reference provides a good starting point for work-progress observation support.

scholarly journals Nanoforest: Polyaniline Nanotubes Modified with Carbon Nano-Onions as a Nanocomposite Material for Easy-to-Miniaturize High-Performance Solid-State Supercapacitors

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1408 ◽  
Author(s):  
Piotr Olejnik ◽  
Marianna Gniadek ◽  
Luis Echegoyen ◽  
Marta Plonska-Brzezinska
Keyword(s):  
Solid State ◽  
High Performance ◽  
Low Cost ◽  
Electron Microscopic ◽  
Thin Gold Film ◽  
Long Term Stability ◽  
Developed Surface ◽  
Scanning Electron Microscopic ◽  
Sem Analyses

This article describes a facile low-cost synthesis of polyaniline nanotube (PANINT)–carbon nano-onion (CNO) composites for solid-state supercapacitors. Scanning electron microscopic (SEM) analyses indicate a uniform and ordered composition for the conducting polymer nanotubes immobilized on a thin gold film. The obtained nanocomposites exhibit a brush-like architecture with a specific capacitance of 946 F g−1 at a scan rate of 1 mV s−1. In addition, the nanocomposites offer high conductivity and a porous and well-developed surface area. The PANINT–CNO nanocomposites were tested as electrodes with high potential and long-term stability for use in easy-to-miniaturize high-performance supercapacitor devices.

Development of a Solid-State Inflation Balloon Deorbiter

2016 ◽  
Author(s):  
Morgan Roddy ◽  
Adam Huang
Keyword(s):  
Solid State ◽  
Aerodynamic Drag ◽  
Low Cost ◽  
Full Range ◽  
Gas Generator ◽  
Satellite Mission ◽  
Micro Electro Mechanical Systems ◽  
Small Satellites ◽  
Metal Insulator Metal ◽  
Resistive Heater

In this paper we report on the current development of the Solid State Inflation Balloon (SSIB), a simple, reliable, low-cost, non-propulsive deorbit mechanism for the full range of small satellites (<180kg). Small satellites typically rely on aerodynamic drag to deorbit within the FAA’s 25 year requirements. The SSIB will enhance aerodynamic drag by inflating a balloon at the end-of-life of a satellite mission. This technology will provide a scalable and non-existing capability, low-cost deorbit, for applications in the full-range of smallsats, from CubeSats to MicroSats. The proposed SSIB system is composed of three major components: a Micro-Electro-Mechanical Systems (MEMS) Solid-State Gas Generator (SSGG) chip, a balloon structure made of thin metallized polyimide films such as Kapton® HN composed of multiple lenticular gores which will form a spherical balloon, and a subsystem package suitable for spacecraft integration. The SSGG is composed of a 2D addressable array of Sodium Azide (NaN3) crystals on a glass substrate. The crystals are contained in wells formed by a thick-film of epoxy polymer (SU-8). Under each well is a resistive heater that is selectively addressed using Metal-Insulator-Metal (MIM) diode networks. When heated to above 350 °C, the NaN3 spontaneously decomposes to generate N2 gas in time scales on the order of 10 milliseconds. Each well can be designed with a typical volume of 10−15 m3 to 10−6 m3 of NaN3. The SSIB system has built-in redundancy due to the fact that the SSGG is a scalable chip design and can incorporate as many gas generating wells as a mission may dictate. Additionally, the SSIB can mitigate balloon leaks by sequential deployment of additional gas wells and can thereby maintain the inflated state of the balloon. The SSIB system will be low power (< 1 W) and have low mass (mass is proportional to the size of the required balloon). Initial simulations have shown that the SSIB can deorbit small satellites from above 1000 km within 25 years.

Demonstration of a Solid-State Inflation Balloon Deorbiter

2017 ◽  
Author(s):  
Morgan Roddy ◽  
Haden Hodges ◽  
Larry Roe ◽  
Po-Hao Adam Huang
Keyword(s):  
Solid State ◽  
Aerodynamic Drag ◽  
Low Cost ◽  
Full Range ◽  
Space Environment ◽  
Gas Generator ◽  
Satellite Mission ◽  
Micro Electro Mechanical Systems ◽  
Small Satellites ◽  
Resistive Heater

This paper updates on the recent development of the novel Solid State Inflation Balloon (SSIB), a simple, reliable, low-cost, non-propulsive deorbit mechanism for the full range of small satellites, defined by NASA as less than 180 kg. It aims to focus on the recent demonstration, for the first time, inflation of a ∼10 cm sized balloon in a vacuum chamber. Small satellites typically rely on aerodynamic drag to deorbit within the FAA’s 25 year requirements. The SSIB will enhance aerodynamic drag by inflating a balloon at the end-of-life of a satellite mission. This technology will provide a scalable and non-existing capability, low-cost deorbit, for applications in the full-range of smallsats, from CubeSats to MicroSats. The SSIB system is composed of three major components: a Micro-Electro-Mechanical Systems (MEMS) Solid-State Gas Generator (SSGG) chip, a balloon structure made of thin film compatible with space environment (i.e. Mylar, Kapton, or Teflon), and a sub-system package suitable for spacecraft integration. The SSGG is composed of a 2D addressable array of sodium azide (NaN3) crystals, confined by Su-8 wells, on a glass substrate. Current versions include 2×2 and 8×8 arrays designed for a full range of small satellites. Under each well is a resistive heater and when heated to above 350 °C, the NaN3 spontaneously decomposes to generate N2 gas in time scales on the order of 10 milliseconds. Each well is designed with a typical volume of 10–15 m3 to 10−6 m3 of NaN3 (i.e. 1,500 μm × 1,500 μm × 150 μm on the larger end of the spectrum). The SSIB system is low power (∼1 W per well for less than 10 seconds) and have low mass (∼100 grams, where mass is dominated by the size of the required balloon). Initial simulations have shown that the SSIB with balloons of 1 m2 cross-section can deorbit small satellites from above 1000 km well within 25 years.

scholarly journals Achieving long cycle life for all-solid-state rechargeable Li-I2 battery by a confined dissolution strategy

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhu Cheng ◽  
Hui Pan ◽  
Fan Li ◽  
Chun Duan ◽  
Hang Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Low Cost ◽  
Liquid System ◽  
Shuttle Effect ◽  
Long Cycle Life ◽  
Discharge Product ◽  
High Theoretical Capacity ◽  
Electrochemical Redox ◽  
Dispersion Layer

AbstractRechargeable Li-I2 battery has attracted considerable attentions due to its high theoretical capacity, low cost and environment-friendliness. Dissolution of polyiodides are required to facilitate the electrochemical redox reaction of the I2 cathode, which would lead to a harmful shuttle effect. All-solid-state Li-I2 battery totally avoids the polyiodides shuttle in a liquid system. However, the insoluble discharge product at the conventional solid interface results in a sluggish electrochemical reaction and poor rechargeability. In this work, by adopting a well-designed hybrid electrolyte composed of a dispersion layer and a blocking layer, we successfully promote a new polyiodides chemistry and localize the polyiodides dissolution within a limited space near the cathode. Owing to this confined dissolution strategy, a rechargeable and highly reversible all-solid-state Li-I2 battery is demonstrated and shows a long-term life of over 9000 cycles at 1C with a capacity retention of 84.1%.

scholarly journals Multi-channel impedance analyzer for automated testing of networks and biomaterials

2020 ◽  
Vol 6 (3) ◽  
pp. 414-417
Author(s):  
Wolfram Schmidt ◽  
Carsten Tautorat ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow ◽  
Frank Kamke ◽  
...  
Keyword(s):  
Low Cost ◽  
Single Frequency ◽  
Impedance Analyzer ◽  
Biomedical Sensors ◽  
Cost System ◽  
Reference Measurements ◽  
Functional Biomaterials ◽  
Multiple Samples

AbstractImpedance spectroscopy represents a basic operating principle for biomedical sensors, bioimpedance spectroscopy, electrochemical analyses and for characterization of functional biomaterials. For automated long-term investigations, an impedance analyzer for multi-channel testing of up to eight passive two-pole networks is presented in this paper. Its operating system is application-specific adapted to the required test functionalities and measuring ranges. Measurements are based on a commercially available integrated impedance converter circuit. Our current analyzer setup is capable of measuring impedance values from 50 kΩ up to 10 MΩ with automated range selection for most accurate results. The impedance under test is excited with a single frequency of 1 kHz. An impedance accuracy of 1.5 % was determined in reference measurements. The presented impedance analyzer is a low cost system ready for use particularly in long-term characterization of dielectric networks, such as material properties, with multiple samples.

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance

scholarly journals Wittichenite semiconductor of Cu3BiS3 films for efficient hydrogen evolution from solar driven photoelectrochemical water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dingwang Huang ◽  
Lintao Li ◽  
Kang Wang ◽  
Yan Li ◽  
Kuang Feng ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Low Cost ◽  
Solar Hydrogen ◽  
Onset Potential ◽  
Term Stability ◽  
Long Term Stability ◽  
Solar Water Splitting ◽  
Current Densities

AbstractA highly efficient, low-cost and environmentally friendly photocathode with long-term stability is the goal of practical solar hydrogen evolution applications. Here, we found that the Cu3BiS3 film-based photocathode meets the abovementioned requirements. The Cu3BiS3-based photocathode presents a remarkable onset potential over 0.9 VRHE with excellent photoelectrochemical current densities (~7 mA/cm2 under 0 VRHE) and appreciable 10-hour long-term stability in neutral water solutions. This high onset potential of the Cu3BiS3-based photocathode directly results in a good unbiased operating photocurrent of ~1.6 mA/cm2 assisted by the BiVO4 photoanode. A tandem device of Cu3BiS3-BiVO4 with an unbiased solar-to-hydrogen conversion efficiency of 2.04% is presented. This tandem device also presents high stability over 20 hours. Ultimately, a 5 × 5 cm2 large Cu3BiS3-BiVO4 tandem device module is fabricated for standalone overall solar water splitting with a long-term stability of 60 hours.

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