scholarly journals Instrumentação de Baixo Custo em Coluna de Solo para Monitoramento Time-Lapse da Ascensão Capilar / Low Cost Soil Column Instrumentation for Time-Lapse Monitoring of Rising Damp

2021 ◽  
Vol 5 (1) ◽  
pp. 226-240
Author(s):  
Nicolas Guimarães Ohofugi ◽  
Manuelle Santos Góis ◽  
Katherin Rocio Cano Bezerra da Costa ◽  
André Luís Brasil Cavalcante
Keyword(s):  
Low Cost ◽  
Soil Column ◽  
Time Lapse ◽  
Rising Damp

scholarly journals Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Han Wang ◽  
Gloria M. Conover ◽  
Song-I Han ◽  
James C. Sacchettini ◽  
Arum Han
Keyword(s):  
Drug Treatment ◽  
Single Cell ◽  
Mycobacterium Smegmatis ◽  
Culture Media ◽  
Low Cost ◽  
Bacterial Pathogen ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Phenotype

AbstractAnalysis of growth and death kinetics at single-cell resolution is a key step in understanding the complexity of the nonreplicating growth phenotype of the bacterial pathogen Mycobacterium tuberculosis. Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M. smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device. A clear morphological change leading to significant swelling at the poles of the bacterial membrane was observed during drug treatment. In addition, a small subpopulation of cells surviving treatment by frontline antibiotics was observed to recover and achieve robust replicative growth once regular culture media was provided, suggesting the possibility of identifying and isolating nonreplicative mycobacteria. This device is a simple, easy-to-use, and low-cost solution for studying the single-cell phenotype and growth dynamics of mycobacteria, especially during drug treatment.

scholarly journals Time-lapse cross-hole electrical resistivity tomography (CHERT) for monitoring seawater intrusion dynamics in a Mediterranean aquifer

2019 ◽  
Author(s):  
Andrea Palacios ◽  
Juan José Ledo ◽  
Niklas Linde ◽  
Linda Luquot ◽  
Fabian Bellmunt ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seawater Intrusion ◽  
Electrical Resistivity Tomography ◽  
Low Cost ◽  
Heavy Rain ◽  
Time Lapse ◽  
Resistivity Tomography ◽  
Bulk Electrical Conductivity ◽  
Spatial Coverage

Abstract. Surface electrical resistivity tomography (ERT) is a widely used tool to study seawater intrusion (SWI). It is noninvasive and offers a high spatial coverage at a low cost, but it is strongly affected by decreasing resolution with depth. We conjecture that the use of CHERT (cross-hole ERT) can partly overcome these resolution limitations since the electrodes are placed at depth, which implies that the model resolution does not decrease in the zone of interest. The objective of this study is to evaluate the CHERT for imaging the SWI and monitoring its dynamics at the Argentona site, a well-instrumented field site of a coastal alluvial aquifer located 40 km NE of Barcelona. To do so, we installed permanent electrodes around boreholes attached to the PVC pipes to perform time-lapse monitoring of the SWI on a transect perpendicular to the coastline. After two years of monitoring, we observe variability of SWI at different time scales: (1) natural seasonal variations and aquifer salinization that we attribute to long-term drought and (2) short-term fluctuations due to sea storms or flooding in the nearby stream during heavy rain events. The spatial imaging of bulk electrical conductivity allows us to explain non-trivial salinity profiles in open boreholes (step-wise profiles really reflect the presence of fresh water at depth). By comparing CHERT results with traditional in situ measurements such as electrical conductivity of water samples and bulk electrical conductivity from induction logs, we conclude that CHERT is a reliable and cost-effective imaging tool for monitoring SWI dynamics.

scholarly journals Time-lapse cross-hole electrical resistivity tomography (CHERT) for monitoring seawater intrusion dynamics in a Mediterranean aquifer

2020 ◽  
Vol 24 (4) ◽  
pp. 2121-2139 ◽  
Author(s):  
Andrea Palacios ◽  
Juan José Ledo ◽  
Niklas Linde ◽  
Linda Luquot ◽  
Fabian Bellmunt ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seawater Intrusion ◽  
Electrical Resistivity Tomography ◽  
Low Cost ◽  
Heavy Rain ◽  
Time Lapse ◽  
Resistivity Tomography ◽  
Bulk Electrical Conductivity ◽  
Spatial Coverage

Abstract. Surface electrical resistivity tomography (ERT) is a widely used tool to study seawater intrusion (SWI). It is noninvasive and offers a high spatial coverage at a low cost, but its imaging capabilities are strongly affected by decreasing resolution with depth. We conjecture that the use of CHERT (cross-hole ERT) can partly overcome these resolution limitations since the electrodes are placed at depth, which implies that the model resolution does not decrease at the depths of interest. The objective of this study is to test the CHERT for imaging the SWI and monitoring its dynamics at the Argentona site, a well-instrumented field site of a coastal alluvial aquifer located 40 km NE of Barcelona. To do so, we installed permanent electrodes around boreholes attached to the PVC pipes to perform time-lapse monitoring of the SWI on a transect perpendicular to the coastline. After 2 years of monitoring, we observe variability of SWI at different timescales: (1) natural seasonal variations and aquifer salinization that we attribute to long-term drought and (2) short-term fluctuations due to sea storms or flooding in the nearby stream during heavy rain events. The spatial imaging of bulk electrical conductivity allows us to explain non-monotonic salinity profiles in open boreholes (step-wise profiles really reflect the presence of freshwater at depth). By comparing CHERT results with traditional in situ measurements such as electrical conductivity of water samples and bulk electrical conductivity from induction logs, we conclude that CHERT is a reliable and cost-effective imaging tool for monitoring SWI dynamics.

A time-lapse seismic repeatability test using the P-Cable high-resolution 3D marine acquisition system

2020 ◽  
Vol 39 (7) ◽  
pp. 480-487
Author(s):  
Patrick Smith ◽  
Brandon Mattox
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Low Cost ◽  
Low Frequency ◽  
Time Lapse ◽  
Seismic Signal ◽  
Residual Energy ◽  
Acquisition System ◽  
Positioning Errors ◽  
Seismic Surveying

The P-Cable high-resolution 3D marine acquisition system tows many short, closely separated streamers behind a small source. It can provide 3D seismic data of very high temporal and spatial resolution. Since the system is containerized and has small dimensions, it can be deployed at short notice and relatively low cost, making it attractive for time-lapse seismic reservoir monitoring. During acquisition of a 3D high-resolution survey in the Gulf of Mexico in 2014, a pair of sail lines were repeated to form a time-lapse seismic test. We processed these in 2019 to evaluate their geometric and seismic repeatability. Geometric repetition accuracy was excellent, with source repositioning errors below 10 m and bin-based receiver positioning errors below 6.25 m. Seismic data comparisons showed normalized root-mean-square difference values below 10% between 40 and 150 Hz. Refinements to the acquisition system since 2014 are expected to further improve repeatability of the low-frequency components. Residual energy on 4D difference seismic data was low, and timing stability was good. We conclude that the acquisition system is well suited to time-lapse seismic surveying in areas where the reservoir and time-lapse seismic signal can be adequately imaged by small-source, short-offset, low-fold data.

Feasibility of time-lapse gravity and gravity gradiometry monitoring for steam-assisted gravity drainage reservoirs

Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. WA99-WA111 ◽  
Author(s):  
Anya Reitz ◽  
Richard Krahenbuhl ◽  
Yaoguo Li
Keyword(s):  
Heavy Oil ◽  
Production Efficiency ◽  
Low Cost ◽  
Time Lapse ◽  
Gravity Drainage ◽  
Great Success ◽  
Gravity Gradiometry ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage ◽  
The Cost

There is presently an increased need to monitor production efficiency as heavy oil reservoirs become more economically viable. We present a feasibility study of monitoring steam-assisted gravity drainage (SAGD) reservoirs using time-lapse gravimetry and gravity gradiometry. Even though time-lapse seismic has historically shown great success for SAGD monitoring, the gravimetry and gravity gradiometry methods offer a low-cost interseismic alternative that can complement the seismic method, increase the survey frequency, and decrease the cost of monitoring. In addition, both gravity-based methods are directly sensitive to the density changes that occur as a result of the replacement of heavy oil by steam. Advances in technologies have made both methods viable candidates for consideration in time-lapse reservoir monitoring, and we have numerically evaluated their potential application in monitoring SAGD production. The results indicate that SAGD production should produce a strong anomaly for both methods at typical SAGD reservoir depths. However, the level of detail for steam-chamber geometries and separations that can be recovered from the gravimetry and gravity gradiometry data is site dependent. Gravity gradiometry shows improved monitoring ability, such as better recovery of nonuniform steam movement due to reservoir heterogeneity, at shallower production reservoirs. Gravimetry has the ability to detect SAGD steam-chamber growth to greater depths than does gravity gradiometry, although with decreasing resolution of the expanding steam chambers.

scholarly journals Monitoring the Snowpack Volume in a Sinkhole on Mount Lebanon using Time Lapse Photogrammetry

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3890 ◽  
Author(s):  
Charbel Chakra ◽  
Simon Gascoin ◽  
Janine Somma ◽  
Pascal Fanise ◽  
Laurent Drapeau
Keyword(s):  
Water Resources ◽  
Low Cost ◽  
Large Fraction ◽  
Hydrological Regime ◽  
Time Lapse ◽  
Daily Basis ◽  
Digital Elevation ◽  
Natural Snow ◽  
Remote Sensing Techniques ◽  
Topographic Surveys

Lebanon has experienced serious water scarcity issues recently, despite being one of the wealthiest countries in the Middle East for water resources. A large fraction of the water resources originates from the melting of the seasonal snow on Mount Lebanon. Therefore, continuous and systematic monitoring of the Lebanese snowpack is becoming crucial. The top of Mount Lebanon is punctuated by karstic hollows named sinkholes, which play a key role in the hydrological regime as natural snow reservoirs. However, monitoring these natural snow reservoirs remains challenging using traditional in situ and remote sensing techniques. Here, we present a new system in monitoring the evolution of the snowpack volume in a pilot sinkhole located in Mount Lebanon. The system uses three compact time-lapse cameras and photogrammetric software to reconstruct the elevation of the snow surface within the sinkhole. The approach is validated by standard topographic surveys. The results indicate that the snow height can be retrieved with an accuracy between 20 and 60 cm (residuals standard deviation) and a low bias of 50 cm after co-registration of the digital elevation models. This system can be used to derive the snowpack volume in the sinkhole on a daily basis at low cost.

A low-cost automated focusing system for time-lapse microscopy

2009 ◽  
Vol 20 (2) ◽  
pp. 027003 ◽  
Author(s):  
E F Wright ◽  
D M Wells ◽  
A P French ◽  
C Howells ◽  
N M Everitt
Keyword(s):  
Low Cost ◽  
Time Lapse ◽  
Time Lapse Microscopy

scholarly journals THE POTENTIAL OF LOW-COST RPAS FOR MULTI-VIEW RECONSTRUCTION OF SUB-VERTICAL ROCK FACES

2016 ◽  
Vol XLI-B5 ◽  
pp. 909-916 ◽  
Author(s):  
K. Thoeni ◽  
D. E. Guccione ◽  
M. Santise ◽  
A. Giacomini ◽  
R. Roncella ◽  
...  
Keyword(s):  
Low Cost ◽  
Empirical Finding ◽  
Time Lapse ◽  
3D Models ◽  
Good Alternative ◽  
Rock Face ◽  
Self Calibration ◽  
Manual Adjustment ◽  
View Reconstruction ◽  
Rock Faces

The current work investigates the potential of two low-cost off-the-shelf quadcopters for multi-view reconstruction of sub-vertical rock faces. The two platforms used are a DJI Phantom 1 equipped with a Gopro Hero 3+ Black and a DJI Phantom 3 Professional with integrated camera. The study area is a small sub-vertical rock face. Several flights were performed with both cameras set in time-lapse mode. Hence, images were taken automatically but the flights were performed manually as the investigated rock face is very irregular which required manual adjustment of the yaw and roll for optimal coverage. The digital images were processed with commercial SfM software packages. Several processing settings were investigated in order to find out the one providing the most accurate 3D reconstruction of the rock face. To this aim, all 3D models produced with both platforms are compared to a point cloud obtained with a terrestrial laser scanner. Firstly, the difference between the use of coded ground control targets and the use of natural features was studied. Coded targets generally provide the best accuracy, but they need to be placed on the surface, which is not always possible, as sub-vertical rock faces are not easily accessible. Nevertheless, natural features can provide a good alternative if wisely chosen as shown in this work. Secondly, the influence of using fixed interior orientation parameters or self-calibration was investigated. The results show that, in the case of the used sensors and camera networks, self-calibration provides better results. To support such empirical finding, a numerical investigation using a Monte Carlo simulation was performed.

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