Examination of a New Remedial Technology for Capping Contaminated Sediments: Large-Scale Laboratory Evaluation of Sediment Mixing and Cap Resistance to Erosive Forces

1998 ◽  
Vol 8 (3) ◽  
pp. 37-58 ◽  
Author(s):  
John H. Hull ◽  
Joseph M. Jersak ◽  
Blair J. McDonald
Keyword(s):  
Large Scale ◽  
Contaminated Sediments ◽  
Laboratory Evaluation ◽  
Sediment Mixing

Field and laboratory evaluation of DGT for predicting metal bioaccumulation and toxicity in the freshwater bivalve Hyridella australis exposed to contaminated sediments

2018 ◽  
Vol 243 ◽  
pp. 862-871 ◽  
Author(s):  
Elvio D. Amato ◽  
Chamani P.M. Marasinghe Wadige ◽  
Anne M. Taylor ◽  
William A. Maher ◽  
Stuart L. Simpson ◽  
...  
Keyword(s):  
Contaminated Sediments ◽  
Laboratory Evaluation ◽  
Metal Bioaccumulation ◽  
Freshwater Bivalve

Laboratory evaluation of malathion for controlling the desert locust, Schistocerca gregaria (Forsk.)

1969 ◽  
Vol 59 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Hafiz Ahmed
Keyword(s):  
Laboratory Tests ◽  
Large Scale ◽  
Schistocerca Gregaria ◽  
Laboratory Data ◽  
Laboratory Evaluation ◽  
Desert Locust ◽  
Simultaneous Application

Experiments were carried out to remove existing doubts about the toxicity (and therefore cost per unit killing power) of malathion to adults of Schistocerca gregaria (Forsk.) which have arisen from earlier field and laboratory tests. Malathion is shown to be almost as toxic to these insects as γ-BHC, but superior in speed of action. These observations are in agreement with the performance of these two compounds in the field.Subdivision of a dose of malathion with simultaneous application at two loci increased its toxicity. This, as well as other factors, brings the value of LD50 determinations into question. Recommendations for large-scale use of new insectsicides, based only on laboratory data, may not always be reliable.

scholarly journals Skin and liver diseases induced in flounder (Platichthys flesus) after long-term exposure to contaminated sediments in large-scale mesocosms.

1996 ◽  
Vol 104 (11) ◽  
pp. 1218-1229 ◽  
Author(s):  
A D Vethaak ◽  
J G Jol ◽  
A Meijboom ◽  
M L Eggens ◽  
T Rheinallt ◽  
...  
Keyword(s):  
Liver Diseases ◽  
Large Scale ◽  
Contaminated Sediments ◽  
Platichthys Flesus

scholarly journals Laboratory evaluation of molecular xenomonitoring using mosquito and tsetse fly excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA

2020 ◽  
Vol 3 ◽  
pp. 1734
Author(s):  
Nils Pilotte ◽  
Darren A.N. Cook ◽  
Joseph Pryce ◽  
Michael F. Zulch ◽  
Corrado Minetti ◽  
...  
Keyword(s):  
Large Scale ◽  
Pathogen Detection ◽  
Mosquito Species ◽  
Digital Pcr ◽  
Tsetse Fly ◽  
Laboratory Evaluation ◽  
Tsetse Flies ◽  
Successful Implementation ◽  
Pilot Studies ◽  
Molecular Xenomonitoring

Background:  Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods:  Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent and incompetent vector species, and effects of additional blood feedings post parasite-exposure were evaluated.  Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR (dPCR)) were also compared, with strengths and weaknesses examined for each.       Results:  Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent and incompetent vector mosquito species.  Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible.  However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei.  Testing also suggested that dPCR may facilitate detection through its increased sensitivity.  Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions:  By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible.  However, translation of this methodology from the lab to the field will first require field-based pilot studies aimed at assessing the efficacy of E/F screening.

Performance Evaluation of Degradable Temporary Plugging Agent in Laboratory Experiment

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Shun Liu ◽  
Tiankui Guo ◽  
Zhenhua Rui ◽  
Kegang Ling
Keyword(s):  
Large Scale ◽  
Fracture Initiation ◽  
Laboratory Evaluation ◽  
Stimulated Reservoir Volume ◽  
Closure Stress ◽  
The Core ◽  
Fracture Complexity ◽  
Basic Performance ◽  
Initiation Pressure ◽  
Plugging Performance

Abstract Temporary plugging fracturing is an effective way to enhance the fracture complexity and increase the stimulated reservoir volume (SRV) of unconventional reservoirs. The performance of temporary plugging agents (TPA) directly affects the success rate of temporary plugging. Currently, laboratory evaluation of the plugging effects of the TPA is rarely reported, and there are no industrial standards on laboratory evaluation of TPA plugging. In this study, two new experimental methods were used to evaluate a novel particulate TPA. The plugging performance of the TPA to the core end face and the propped fractures was measured through displacement experiments of cores, and the applicability of its basic performance to the temporary plugging fracturing was verified. Furthermore, the large-scale true triaxial simulation experiment of temporary plugging fracturing was carried out to confirm the influence mechanism of different factors on fracture propagation during temporary plugging. Finally, the influence rule of different types of combinations of TPA and placement patterns on the plugging was obtained based on laboratory evaluation of the conductivity. The results show that the novel TPA causes effective temporary plugging on the core end face and the propped fractures and has the strong plugging performance, and the TPA solubility in the carrying fluids decreases with the increase in the TPA concentration. The basic performance of the TPA meets the requirements of temporary plugging fracturing. If the proppants and 20% fibers are placed within the fracture in the mixed pattern, the fracture is initiated along the direction of the horizontal maximum principal stress. The preset fracture reduces the fracture initiation pressure. The fracture complexity is closely related to the placement pattern of TPA and proppants. If the preset fractures are filled by the uniform mixture or the plug of the 20/40 mesh or 20/80 mesh particulate TPA (4%), fibers (1%), and proppants, the fracture initiation pressure significantly increases, and the complex fractures are formed after fracturing. Effective plugging cannot be formed only by mixing the fibers with the proppants, and the uniform mixture of the proppants and 4% particulate TPA and the 6% particulate TPA at the front end of the fracture form a temporary plugging belt, achieving effective plugging. The fibers improve the conductivity under the low closure stress, and it has a certain effect of temporary plugging under the closure stress above 30 MPa. The research results provide the design consideration for creating the complex fracture by temporary plugging.

scholarly journals Laboratory evaluation of molecular xenomonitoring using mosquito excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA

2019 ◽  
Vol 3 ◽  
pp. 1734 ◽  
Author(s):  
Nils Pilotte ◽  
Darren A.N. Cook ◽  
Joseph Pryce ◽  
Michael F. Zulch ◽  
Corrado Minetti ◽  
...  
Keyword(s):  
Large Scale ◽  
Pathogen Detection ◽  
Mosquito Species ◽  
Digital Pcr ◽  
Laboratory Evaluation ◽  
Tsetse Flies ◽  
Successful Implementation ◽  
Pilot Studies ◽  
Increased Sensitivity ◽  
Molecular Xenomonitoring

Background:  Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods:  Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent- and incompetent-vector species, and effects of additional blood feedings post parasite-exposure were evaluated.  Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR [dPCR]) were also compared, with strengths and weaknesses examined for each.       Results:  Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent- and incompetent-vector mosquito species.  Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible.  However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei.  Testing also suggested that dPCR may facilitate detection through its increased sensitivity.  Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions:  By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible.  However, translation of this methodology from the lab to the field will first require the completion of field-based pilot studies aimed at assessing the efficacy of E/F screening.

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