Laboratory test results on self-hardening grouts for flexible cutoffs

1984 ◽  
Vol 21 (1) ◽  
pp. 185-191 ◽  
Author(s):  
Robert P. Chapuis ◽  
J.-Jacques Paré ◽  
André A. Loiselle
Keyword(s):  
Experimental Program ◽  
Test Results ◽  
James Bay ◽  
Cement Slurry ◽  
Cutoff Wall ◽  
Hydroelectric Project ◽  
Solid States ◽  
Bentonite Slurry ◽  
Laboratory Test Results ◽  
Cutoff Walls

The addition of cement to a bentonite slurry gives a complex material called self-hardening grout which slowly sets to become a clay-like solid. The properties of these mixes are highly dependent on the bentonite and the cement used. Most information available up to now comes from European countries where the technique has been developed. As very little information was available about such mixes in North America, an experimental program was initiated to study their applicability for cutoff walls of certain dams of the James Bay hydroelectric project. The present paper describes the characteristics of different mixes tested in their fluid and solid states. Keywords: bentonite, cement, slurry, cutoff wall.

Parameters affecting the thickness of bentonite cake in cutoff wall construction: case study and physical modeling

2005 ◽  
Vol 42 (2) ◽  
pp. 646-654 ◽  
Author(s):  
Abbas Soroush ◽  
Mohammad Soroush
Keyword(s):  
Physical Model ◽  
Physical Model Test ◽  
Test Results ◽  
Cutoff Wall ◽  
Bentonite Slurry ◽  
Cutoff Walls ◽  
Plastic Concrete ◽  
Wall Construction ◽  
Using Data

Concrete cutoff walls are usually constructed using a panel-by-panel technique in which primary panels are constructed with space between them and then secondary panels are constructed and inserted in the spaces. A small thickness of residual bentonite cake from the slurry used during excavation usually remains in the construction joints between adjacent primary and secondary panels. The thickness of such bentonite-filled joints should be minimized in terms of the performance of the cutoff wall in controlling seepage. This research experimentally evaluated the effects of a number of design and construction parameters on the thickness of the bentonite cake using data from a case study (the cutoff wall of Karkheh Dam). A physical model test was developed and a number of tests were conducted. The test results showed that parameters such as age of the primary panels, cement content of the slurry, quantity of additives in the slurry, and circulation versus noncirculation of the slurry are responsible for the thickness of the bentonite cake. The results are presented and analyzed.Key words: cutoff wall, plastic concrete, bentonite slurry, bentonite cake, physical model.

scholarly journals Application of a Bentonite Slurry Modified by Polyvinyl Alcohol in the Cutoff of a Landfill

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Guozhong Dai ◽  
Yanmin Sheng ◽  
Yutao Pan ◽  
Guicai Shi ◽  
Shujin Li
Keyword(s):  
Polyvinyl Alcohol ◽  
Adsorption Capacity ◽  
Permeability Coefficient ◽  
Cutoff Wall ◽  
Treatment Results ◽  
Bentonite Slurry ◽  
Cutoff Walls ◽  
Adsorption Capability

Soil-bentonite cutoff walls are usually used to contain the contaminants of landfills. The pumpability, permeability, and adsorption capability of the slurry are all crucial to the performance of the cutoff wall. In this study, the effect of polyvinyl alcohol (PVA) was used to improve the performance of bentonite slurry. A series of lab tests were conducted to evaluate the pumpability, permeability, and adsorption capacity with different concentrations of PVA treatment. Results show that the addition of PVA can increase the fluidity and pumpable period of slurry, which facilitates the casting and grouting during construction. The addition of PVA also helps to reduce the permeability coefficient of slurry and improve the adsorption capability which enhances the cutoff performance of the walls.

Thermal Decomposition of Aviation Fuel

1982 ◽  
Author(s):  
A. E. Peat
Keyword(s):  
Engine Performance ◽  
Aviation Fuel ◽  
Experimental Program ◽  
Test Results ◽  
Fuel Injector ◽  
Fuel Flow ◽  
Laboratory Test Results ◽  
Insoluble Compounds ◽  
Initial Results ◽  
Tube Metal

Thermal stressing of aviation fuels can promote the formation of fuel insoluble compounds. Their presence within the fuel system is troublesome to aviation gas turbine manufacturers as they can adversely affect engine performance. To study this phenomenon an experimental program based on a fuel rig capable of reproducing relevant engine conditions and featuring an instrumented replica fuel injector feed arm was devised. The initial objectives are to rate quantitatively the effects of bulk fuel and metal temperatures, fuel flow rates and fuel types on the production of fuel insoluble matter, both deposited and suspended. This report presents the initial results which indicate a relationship between the weight of “tube” carbon deposits and a function of “tube” metal temperature and fuel velocity. Further, this approach could provide the much interface between the engine and laboratory test results.

New Horizons of Well Bonding: Cement Expansion in Absence of Water Access

2021 ◽  
Author(s):  
Elizaveta Bakhareva ◽  
Vasilii Sukhachev ◽  
Alexander Sozonov ◽  
Anastasia Zinovyeva ◽  
Olesya Olennikova ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Sodium Chloride ◽  
Linear Expansion ◽  
Strength Development ◽  
Gas Migration ◽  
Test Results ◽  
Cement Slurry ◽  
Laboratory Test Results ◽  
Cement System ◽  
External Water

Abstract Zonal isolation for primary cementing is generally of concern when there is potential for gas migration. The challenge for the industry is to achieve a long-term annular cement seal and prevent gas migration. This paper focuses on the problem of ensuring sufficient bulk expansion of set cement without access to external water and optimizing the cement slurry formulation. The approach to solving this problem is creative and simple within the industry. One of the reasons for wellbore gas migration and inter-connected flows can be due to cement shrinkage over time. This study focuses on laboratory testing of an expanding cement system in the absence of water and analysis of test results of novel the cement system in terms of its implementation on well with high gas migration potential. The cement system behavior will also be described in terms of rheological, filtration and mechanical properties and compared to conventional expanding cement slurries. This approach can be used to improve cement bonding with the aim of minimizing future remedial jobs. Several approaches were implemented to achieve noticeable expansion in anhydrous media. One of the methods showed it was feasible to achieve 1.27% linear expansion in set cement without external water contact, while linear expansion in the presence of water was 0.78%. This method uses the addition of sodium chloride (NaCl) and while it has been previously described in literature, no practical design/testing directions have been given. The study identified the most effective concentration of sodium chloride required for set cement expansion without water availability. The study described how other cement system properties permitted better results in terms of placement quality of highly salt-saturated cement. Overall, complex laboratory test results provide evidence of effective linear expansion in set cement in the absence of external water. The optimization of cement slurry properties was focused on obtaining optimal thickening time, rheology and compressive strength, which was complicated by the presence of a high concentration of sodium chloride. An expanding cement system was successfully tested in the absence of water showing positive linear expansion. A new approach for testing expanding cement systems in the absence of water was introduced how excessive linear expansion could be compromised with compressive strength development. The research results have shown that the use of NaCl additive in high concentrations in high SVF self-healing systems provided improved performance when aiming for effective linear expansion in set cement in the absence of water.

Effect of Ibuprofen on Serum Laboratory Test Results

1983 ◽  
Vol 40 (6) ◽  
pp. 1025-1034
Author(s):  
Carol L. Colvin ◽  
Raymond J. Townsend ◽  
William R. Gillespie ◽  
Kenneth S. Albert
Keyword(s):  
Laboratory Test ◽  
Test Results ◽  
Laboratory Test Results

Quality benchmarking of smartphone laboratory medicine applications: comparison of laboratory medicine specialists’ and non-laboratory medicine professionals’ evaluation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Snežana Jovičić ◽  
Joanna Siodmiak ◽  
Marta Duque Alcorta ◽  
Maximillian Kittel ◽  
Wytze Oosterhuis ◽  
...  
Keyword(s):  
Information Quality ◽  
Rating Scale ◽  
Laboratory Medicine ◽  
Test Results ◽  
Content Quality ◽  
Laboratory Test Results ◽  
System Usability Scale ◽  
Mobile Health Applications ◽  
Fit For Purpose ◽  
Health Applications

AbstractObjectivesThere are many mobile health applications (apps) now available and some that use in some way laboratory medicine data. Among them, patient-oriented are of the lowest content quality. The aim of this study was to compare the opinions of non-laboratory medicine professionals (NLMP) with those of laboratory medicine specialists (LMS) and define the benchmarks for quality assessment of laboratory medicine apps.MethodsTwenty-five volunteers from six European countries evaluated 16 selected patient-oriented apps. Participants were 20–60 years old, 44% were females, with different educational degrees, and no professional involvement in laboratory medicine. Each participant completed a questionnaire based on the Mobile Application Rating Scale (MARS) and the System Usability Scale, as previously used for rating the app quality by LMS. The responses from the two groups were compared using the Mann-Whitney U test and Spearman correlation.ResultsThe median total score of NLMP app evaluation was 2.73 out of 5 (IQR 0.95) compared to 3.78 (IQR 1.05) by the LMS. All scores were statistically significantly lower in the NLMP group (p<0.05), except for the item Information quality (p=0.1631). The suggested benchmarks for a useful appear: increasing awareness of the importance and delivering an understanding of persons’ own laboratory test results; understandable terminology; easy to use; appropriate graphic design, and trustworthy information.ConclusionsNLMP’ evaluation confirmed the low utility of currently available laboratory medicine apps. A reliable app should contain trustworthy and understandable information. The appearance of an app should be fit for purpose and easy to use.

scholarly journals COVID-19 and pregnancy – where are we now? A review

2020 ◽  
Vol 48 (5) ◽  
pp. 428-434 ◽  
Author(s):  
Aleksandra Rajewska ◽  
Wioletta Mikołajek-Bedner ◽  
Joanna Lebdowicz-Knul ◽  
Małgorzata Sokołowska ◽  
Sebastian Kwiatkowski ◽  
...  
Keyword(s):  
Case Fatality ◽  
Fetal Distress ◽  
Delivery Mode ◽  
Test Results ◽  
Rt Pcr ◽  
Third Trimester ◽  
The Third ◽  
Laboratory Test Results ◽  
Protective Antibodies ◽  
Polymerase Chain

AbstractThe new acute respiratory disease severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is highly contagious. It has caused many deaths, despite a relatively low general case fatality rate (CFR). The most common early manifestations of infection are fever, cough, fatigue and myalgia. The diagnosis is based on the exposure history, clinical manifestation, laboratory test results, chest computed tomography (CT) findings and a positive reverse transcription-polymerase chain reaction (RT-PCR) result for coronavirus disease 2019 (COVID-19). The effect of SARS-CoV-2 on pregnancy is not already clear. There is no evidence that pregnant women are more susceptible than the general population. In the third trimester, COVID-19 can cause premature rupture of membranes, premature labour and fetal distress. There are no data on complications of SARS-CoV-2 infection before the third trimester. COVID-19 infection is an indication for delivery if necessary to improve maternal oxygenation. Decision on delivery mode should be individualised. Vertical transmission of coronavirus from the pregnant woman to the fetus has not been proven. As the virus is absent in breast milk, the experts encourage breastfeeding for neonatal acquisition of protective antibodies.

scholarly journals Physical, Deformation, and Stiffness Properties of Recycled Concrete Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas
Keyword(s):  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Granulometric Analysis ◽  
Stiffness Properties ◽  
Grain Distribution ◽  
Natural Aggregates ◽  
Critical Reduction

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.

scholarly journals Atypical anti-glomerular basement membrane disease with anti-GBM antibody negativity and ANCA positivity: a case report

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Na Guo ◽  
Qinghua Yin ◽  
Song Lei ◽  
Yanjun He ◽  
Ping Fu
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Rare Case ◽  
Test Results ◽  
Serum Samples ◽  
Tissue Samples ◽  
Case Presentation ◽  
Severe Renal Insufficiency ◽  
Laboratory Test Results ◽  
Organ Specific

Abstract Background Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disease that involves the lung and kidneys and leads to rapid glomerulonephritis progression, with or without diffuse alveolar hemorrhage, and even respiratory failure. Classic cases of anti-GBM disease are diagnosed based on the presence of the anti-GBM antibody in serum samples and kidney or lung biopsy tissue samples. However, atypical cases of anti-GBM disease are also seen in clinical practice. Case presentation We herein report the rare case of a patient with atypical anti-GBM disease whose serum was negative for the anti-GBM antibody but positive for the myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (p-ANCA) and another atypical ANCA. Laboratory test results showed severe renal insufficiency with a creatinine level of 385 μmol/L. Renal biopsy specimen analysis revealed 100% glomeruli with crescents; immunofluorescence showed immunoglobulin G (IgG) linearly deposited alongside the GBM. Finally, the patient was discharged successfully after treatment with plasmapheresis, methylprednisolone and prednisone. Conclusion This patient, whose serum was negative for the anti-GBM antibody but positive for p-ANCA and another atypical ANCA, had a rare case of anti-GBM disease. Insights from this unusual case might help physicians diagnose rare forms of glomerulonephritis and treat affected patients in a timely manner.

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