scholarly journals Review on manuscript hess-2020-341 Technical Note: Evaluation of a low-cost evaporation protection method for portable water samplers

2020 ◽  
2020 ◽  
Author(s):  
Jana von Freyberg ◽  
Julia L. A. Knapp ◽  
Andrea Rücker ◽  
Bjørn Studer ◽  
James W. Kirchner

Abstract. Automated field sampling of streamwater or precipitation for subsequent analysis of stable water isotopes (2H and 18O) is often conducted with off-the-shelf automated samplers. However, water samples stored in the field for days and weeks in open bottles inside autosamplers undergo isotopic fractionation and vapor mixing, thus altering their isotopic signature. We therefore designed an evaporation protection method which modifies autosampler bottles using a syringe housing and silicone tube, and tested whether this method reduces evaporative fractionation and vapor mixing in water samples stored for up to 24 days in ISCO autosamplers (Teledyne ISCO., Lincoln, US). Laboratory and field tests under different temperature and humidity conditions showed that water samples in bottles with evaporation protection were far less altered by evaporative fractionation and vapor mixing than samples in conventional open bottles. Our design is a cost-efficient approach to upgrade the 1-litre sample bottles of ISCO 6712 Full-size Portable Samplers, allowing secure water sample collection in warm and dry environments. Our design can be readily adapted (e.g., by using a different syringe size) to fit the bottles used by many other field autosamplers.


2020 ◽  
Vol 24 (12) ◽  
pp. 5821-5834
Author(s):  
Jana von Freyberg ◽  
Julia L. A. Knapp ◽  
Andrea Rücker ◽  
Bjørn Studer ◽  
James W. Kirchner

Abstract. Automated field sampling of streamwater or precipitation for subsequent analysis of stable water isotopes (2H and 18O) is often conducted with off-the-shelf automated samplers. However, when water samples are stored in the field for days and weeks in open bottles inside autosamplers, their isotopic signatures can be altered by evaporative fractionation and vapor mixing. We therefore designed an evaporation protection method which modifies autosampler bottles using a syringe housing and silicone tube, and we tested whether this method reduces evaporative fractionation and vapor mixing in water samples stored for up to 24 d in 6712 full-size portable samplers (Teledyne ISCO, Lincoln, USA). Laboratory and field tests under different temperature and humidity conditions showed that water samples in bottles with evaporation protection were far less altered by evaporative fractionation and vapor mixing than samples in conventional open bottles. Our design is a cost-efficient approach to upgrade the 1 L sample bottles of the ISCO autosamplers, allowing secure water sample collection in warm and dry environments. Our design can be readily adapted (e.g., by using a different syringe size) to fit the bottles used by many other field autosamplers.


Author(s):  
Jana von Freyberg ◽  
Julia L. A. Knapp ◽  
Andrea Rücker ◽  
Bjørn Studer ◽  
James W. Kirchner

2020 ◽  
Vol 2 (2) ◽  
pp. 280-293
Author(s):  
Mathew G. Pelletier ◽  
Greg A. Holt ◽  
John D. Wanjura

The removal of plastic contamination in cotton lint is an issue of top priority to the U.S. cotton industry. One of the main sources of plastic contamination showing up in marketable cotton bales, at the U.S. Department of Agriculture’s classing office, is plastic from the module wrap used to wrap cotton modules produced by the new John Deere round module harvesters. Despite diligent efforts by cotton ginning personnel to remove all plastic encountered during unwrapping of the seed cotton modules, plastic still finds a way into the cotton gin’s processing system. To help mitigate plastic contamination at the gin; an inspection system was developed that utilized low-cost color cameras to see plastic on the module feeder’s dispersing cylinders, that are normally hidden from view by the incoming feed of cotton modules. This technical note presents the design of an automated intelligent machine-vision guided cotton module-feeder inspection system. The system includes a machine-learning program that automatically detects plastic contamination in order to alert the cotton gin personnel as to the presence of plastic contamination on the module feeder’s dispersing cylinders. The system was tested throughout the entire 2019 cotton ginning season at two commercial cotton gins and at one gin in the 2018 ginning season. This note describes the over-all system and mechanical design and provides an over-view and coverage of key relevant issues. Included as an attachment to this technical note are all the mechanical engineering design files as well as the bill-of-materials part source list. A discussion of the observational impact the system had on reduction of plastic contamination is also addressed.


2020 ◽  
Vol 20 (21) ◽  
pp. 13417-13424
Author(s):  
Jake P. Rowe ◽  
Andrew T. Lambe ◽  
William H. Brune

Abstract. Oxidation flow reactors (OFRs) complement environmental smog chambers as a portable, low-cost technique for exposing atmospheric compounds to oxidants such as ozone (O3), nitrate (NO3) radicals, and hydroxyl (OH) radicals. OH is most commonly generated in OFRs via photolysis of externally added O3 at λ=254 nm (OFR254) or combined photolysis of O2 and H2O at λ=185 nm plus photolysis of O3 at λ=254 nm (OFR185) using low-pressure mercury (Hg) lamps. Whereas OFR254 radical generation is influenced by [O3], [H2O], and photon flux at λ=254 nm (I254), OFR185 radical generation is influenced by [O2], [H2O], I185, and I254. Because the ratio of photon fluxes, I185:I254, is OFR-specific, OFR185 performance varies between different systems even when constant [H2O] and I254 are maintained. Thus, calibrations and models developed for one OFR185 system may not be applicable to another. To investigate these issues, we conducted a series of experiments in which I185:I254 emitted by Hg lamps installed in an OFR was systematically varied by fusing multiple segments of lamp quartz together that either transmitted or blocked λ=185 nm radiation. Integrated OH exposure (OHexp) values achieved for each lamp type were obtained using the tracer decay method as a function of UV intensity, humidity, residence time, and external OH reactivity (OHRext). Following previous related studies, a photochemical box model was used to develop a generalized OHexp estimation equation as a function of [H2O], [O3], and OHRext that is applicable for I185:I254≈0.001 to 0.1.


Author(s):  
R. J. Henderson ◽  
J. K. Raine

Parts 1 and 2 of this paper gave a design overview and described the dynamics of a prototype two-degree-of-freedom pneumatic suspension for an ambulance stretcher. This concluding part briefly reviews laboratory shaker table and ambulance road test performance of the suspension with passive pneumatic damping. The suspension system is found to offer compact low-cost isolation with lower natural frequencies than achieved in earlier mechanical systems.


Author(s):  
X. E. Gros

Non-destructive testing (NDT) is a useful tool to assess the structural integrity of components in order to maintain quality and safety standards. A low-cost electromagnetic technique based on eddy currents induced into a material appeared promising for the inspection of composite materials. Experiments were carried out in order to assess the potential of eddy currents in detecting delamination in rubber tyres. Infrared thermography was used to verify inspection results achieved with eddy currents. Non-destructive examination results are presented in this paper; these confirm that eddy current testing is an economically viable alternative for the inspection of steel reinforced truck tyres.


2010 ◽  
Vol 7 (2) ◽  
pp. 757-772 ◽  
Author(s):  
E. Waugh ◽  
M. Mowlem

Abstract. A low-cost Unmanned Aerial Vehicle is compared with those already available and the motivation for its development is established. It is targeted at ship-based science missions and potential applications are described including a specific science case to measure white capping in the deep ocean. The current vehicle includes a range of more than 1000 km, carrying a payload of 2 kg and it can be launched and recovered from a coastal research vessel. The vehicle has flown successfully in Force 4 gusting Force 6–7 wind conditions, an important requirement for operation at sea. Data analysis is performed on images captured by the vehicle to provide a measurement of wave period and white capping fraction. The next stage of the project is to develop a suitable payload and perform a demonstration science mission.


Sign in / Sign up

Export Citation Format

Share Document