scholarly journals Long-Term Monitoring of Atrazine Contamination in Soil by ELISA

2001 ◽  
Vol 84 (1) ◽  
pp. 150-155 ◽  
Author(s):  
Karl Kramer ◽  
Johann Lepschy ◽  
Bertold Hock
Keyword(s):  
Low Cost ◽  
Threshold Value ◽  
Soil Samples ◽  
Sample Throughput ◽  
Atrazine Contamination ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Selection Of ◽  
Hplc Data

Abstract An enzyme-linked immunoassay (ELISA) was used for screening atrazine residues in soil. Samples were annually collected in Southern Germany between 1993 and 1998. An average of 419.5 samples was analyzed per year amounting to 2517 samples. The fraction of positive samples defined by atrazine concentrations >100 μg/kg soil decreased successively from 8% (corresponding to 33 samples) in 1993 to 0.6% (corresponding to 2 samples) in 1998. All positive samples and a selection of negative samples were subsequently validated by HPLC. Comparison of ELISA and HPLC data yielded correlation coefficient values of r= 0.958–0.981 (n= 18–47), except for 1995 when only a correlation of r= 0.864 (n= 18) was obtained. Four samples were overestimated and another 4 were underestimated with respect to the atrazine threshold value of 100 μg/kg soil as revealed by HPLC validation. Thus, 99.68% of 2517 analyzed samples were correctly evaluated. The precision and reproducibility of the ELISA were adequate for a prescreening tool. The low cost per sample and the high sample throughput are not yet achievable by conventional analytical methods. The described combination of ELISA and HPLC has the potential to take advantage of both methods and to restrict determination errors to a minimum.

scholarly journals A Framework for Long-Term Vibration-Based Monitoring of Bridges

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4739
Author(s):  
Emrah Erduran ◽  
Frida Kristin Ulla ◽  
Lone Næss
Keyword(s):  
Strain Energy ◽  
Threshold Value ◽  
Modal Strain Energy ◽  
Damage Initiation ◽  
Damage Indicator ◽  
Damage Indicators ◽  
Long Term Monitoring ◽  
The Impact ◽  
Term Monitoring

A new framework for long-term monitoring of bridges is proposed in order to negate (i) the impact of measurement uncertainties on damage detection in vibration-based structural health monitoring and (ii) the low sensitivity of damage indicators to low levels of damage. The framework is developed using three vibration-based damage indicators that have an intuitive physical correlation with damage: modal curvature, modal strain energy and modal flexibility. The article first quantifies the efficacy of these damage indicators when based on two observations, one from the undamaged state and one from the monitored state, in detecting and locating damage for different damage levels that are simulated on an 84-m long railway bridge. A long-term monitoring framework based on a new parameter defined as the frequency of the damage indicator exceeding the threshold value within a population of observations is developed. Impact of several factors including the damage location, damage indicator used in the framework, and the noise level on the success of the developed framework was investigated through numerical analysis. The new parameter, when used together with modal strain energy, was shown to provide a very clear picture of damage initiation and development over time starting from very low damage levels. Furthermore, the location of the simulated damage can be identified successfully at all damage levels and even for very high noise levels using the proposed framework.

scholarly journals MACRO PHOTOGRAMMETRY FOR THE DAMAGE ASSESSMENT OF ARTWORK PAINTED SURFACES

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 101-107 ◽  
Author(s):  
L. M. Angheluță ◽  
R. Rădvan
Keyword(s):  
Damage Assessment ◽  
Complementary Method ◽  
Physical Deterioration ◽  
Different Types ◽  
Long Term Monitoring ◽  
3D Digitization ◽  
Term Monitoring ◽  
Selection Of ◽  
Full Body

<p><strong>Abstract.</strong> In this paper we are presenting our approach and workflow for macro photogrammetry as a complementary method for 3D digitization of polychromies on wood support. Macro photogrammetry can be used for detailed documentation of physical damages in painting layers, underlayers or support. For a better presentation of the context, a selection of typical physical damages, relevant to this study, are explained. Two case studies are presented. Two wooden icons realized with different techniques and presenting different types of physical deterioration. The experiments detailed within this paper represent the first epoch of long-term monitoring of the restoration interventions for each of these icons. All the stage of our workflow is thoroughly detailed with acquisition parameters and processing settings in order to better understand the results and where things can be improved. For each icon a full body photogrammetry process is described, followed by macro photogrammetry on smaller selected areas on the icons' surfaces. Macro magnifications of 1&amp;thinsp;:&amp;thinsp;1 and 2&amp;thinsp;:&amp;thinsp;1 are obtained by using a dedicated macro lens and extension rings. Lighting setups and focus stacking process are also described for a better understanding of the parameters and settings used.</p>

Comparison of low cost measurement techniques for long-term monitoring of atmospheric ammonia

2001 ◽  
Vol 3 (5) ◽  
pp. 446-453 ◽  
Author(s):  
M. A. Sutton ◽  
B. Miners ◽  
Y. S. Tang ◽  
C. Milford ◽  
G. P. Wyers ◽  
...  
Keyword(s):  
Low Cost ◽  
Measurement Techniques ◽  
Atmospheric Ammonia ◽  
Cost Measurement ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Development of an Inverted Epifluorescence Microscope for Long-Term Monitoring of Bacteria in Multiplexed Microfluidic Devices

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4140
Author(s):  
Amaro Torres-Simón ◽  
María Henar Marino ◽  
Clara Gómez-Cruz ◽  
Marina Cañadas ◽  
Miguel Marco ◽  
...  
Keyword(s):  
Single Cell ◽  
Bacterial Resistance ◽  
Single Cell Analysis ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Cell Analysis ◽  
Antibiotic Development ◽  
Long Term Monitoring ◽  
Term Monitoring

Developing more efficient methods for antibiotic susceptibility testing is a pressing issue in novel drug development as bacterial resistance to antibiotics becomes increasingly common. Microfluidic devices have been demonstrated to be powerful platforms that allow researchers to perform multiplexed antibiotic testing. However, the level of multiplexing within microdevices is limited, evidencing the need of creating simple, low-cost and high-resolution imaging systems that can be integrated in antibiotic development pipelines. This paper describes the design and development of an epifluorescence inverted microscope that enables long-term monitoring of bacteria inside multiplexed microfluidic devices. The goal of this work is to provide a simple microscope powerful enough to allow single-cell analysis of bacteria at a reduced cost. This facilitates increasing the number of microscopes that are simultaneously used for antibiotic testing. We prove that the designed system is able to accurately detect fluorescent beads of 100 nm, demonstrating comparable features to high-end commercial microscopes and effectively achieving the resolution required for single-cell analysis of bacteria. The proposed microscope could thus increase the efficiency in antibiotic testing while reducing cost, size, weight, and power requirements, contributing to the successful development of new antibiotic drugs.

Low-cost long-term monitoring of global climate forcings and feedbacks

1995 ◽  
Vol 31 (2-4) ◽  
pp. 247-271 ◽  
Author(s):  
J. Hansen ◽  
W. Rossow ◽  
B. Carlson ◽  
A. Lacis ◽  
L. Travis ◽  
...  
Keyword(s):  
Global Climate ◽  
Low Cost ◽  
Long Term Monitoring ◽  
Climate Forcings ◽  
Term Monitoring

scholarly journals Methodological considerations for monitoring soil/litter arthropods in tropical rainforests using DNA metabarcoding, with a special emphasis on ants, springtails and termites

2020 ◽  
Vol 4 ◽  
Author(s):  
Yves Basset ◽  
David A. Donoso ◽  
Mehrdad Hajibabaei ◽  
Michael T. G. Wright ◽  
Kate H. J. Perez ◽  
...  
Keyword(s):  
Soil Fauna ◽  
Light Trap ◽  
Common Species ◽  
Soil Samples ◽  
Malaise Trap ◽  
Termite Species ◽  
Dna Metabarcoding ◽  
Long Term Monitoring ◽  
Term Monitoring

Robust data to refute or support claims of global insect decline are currently lacking, particularly for the soil fauna in the tropics. DNA metabarcoding represents a powerful approach for rigorous spatial and temporal monitoring of the taxonomically challenging soil fauna. Here, we provide a detailed field protocol, which was successfully applied in Barro Colorado Island (BCI) in Panama, to collect soil samples and arthropods in a tropical rainforest, to be later processed with metabarcoding. We also estimate the proportion of soil/litter ant, springtail and termite species from the local fauna that can be detected by metabarcoding samples obtained either from Berlese-Tullgren (soil samples), Malaise or light traps. Each collecting method detected a rather distinct fauna. Soil and Malaise trap samples detected 213 species (73%) of all target species. Malaise trap samples detected many ant species, whereas soil samples were more efficient at detecting springtail and termite species. With respect to long-term monitoring of soil-dwelling and common species (more amenable to statistical trends), the best combination of two methods were soil and light trap samples, detecting 94% of the total of common species. A protocol including 100 soil, 40 Malaise and 80 light trap samples annually processed by metabarcoding would allow the long-term monitoring of at least 11%, 18% and 16% of species of soil/litter ants, springtails and termites, respectively, present on BCI, and a high proportion of the total abundance (up to 80% of all individuals) represented by these taxa.

Low-Cost Long-Term Monitoring of Global Climate Forcings and Feedbacks

1996 ◽  
pp. 117-141 ◽  
Author(s):  
J. Hansen ◽  
W. Rossow ◽  
B. Carlson ◽  
A. Lacis ◽  
L. Travis ◽  
...  
Keyword(s):  
Global Climate ◽  
Low Cost ◽  
Long Term Monitoring ◽  
Climate Forcings ◽  
Term Monitoring
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