Effects of laboratory test conditions on the toxicity of silver to aquatic organisms

1998 ◽  
Vol 17 (4) ◽  
pp. 572-578 ◽  
Author(s):  
Russell J. Erickson ◽  
Larry T. Brooke ◽  
Michael D. Kahl ◽  
Fred Vende Venter ◽  
Sandra L. Harting ◽  
...  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Fin O’Flaherty ◽  
Fathi Al-Shawi

AbstractThis study presents a detailed analysis of the lateral forces generated as a result of vertically applied loads to recycled plastic drainage kerbs. These kerbs are a relatively new addition to road infrastructure projects. When concrete is used to form road drainage kerbs, its deformation is minimum when stressed under heavy axle loads. Although recycled plastic kerbs are more environmentally friendly as a construction product, they are less stiff than concrete and tend to deform more under loading leading to a bursting type, lateral force being applied to the haunch materials, the magnitude of which is unknown. A method is proposed for establishing the distribution of these lateral forces resulting from deformation under laboratory test conditions. A load of 400 kN is applied onto a total of six typical kerbs in the laboratory in accordance with the test standard. The drainage kerbs are surrounded with 150 mm of concrete to the front and rear haunch and underneath as is normal during installation. The lateral forces exerted on the concrete surround as a result of deformation of the plastic kerbs are determined via a strain measuring device. Analysis of the test data allows the magnitude of the lateral forces to the surrounding media to be determined and, thereby, ensuring the haunch materials are not over-stressed as a result. The proposed test methodology and subsequent analysis allows for an important laboratory-based assessment of any typical recycled plastic drainage kerbs to be conducted to ensure they are fit-for-purpose in the field.


2017 ◽  
Vol 171 (4) ◽  
pp. 227-238
Author(s):  
Piotr BIELACZYC ◽  
Andrzej SZCZOTKA ◽  
Joseph WOODBURN

Emissions of particulate matter associated with the use of light-duty vehicles are an increasingly important topic, with more and more political attention focused on this issue. Now that direct injection Diesel engines feature DPFs, particle emissions from other engine types operating on other fuels are also of great interest. This paper discusses the phenomenon in general, briefly reviews worldwide legislation and emissions limits and presents the results of a laboratory test programme measuring the particle emissions from a range of vehicles. The experimental programme showed that the engine/fuel type has a greater impact on particle emissions than the test conditions.


Author(s):  
J. S. Harris ◽  
L.K. Ives ◽  
M. B. Peterson

Recent investigations have shown that SbSbS4 is a promising solid lubricant. It exhibits outstanding extreme pressure (EP) performance, and good antiwear behavior under laboratory test conditions. An investigation was undertaken to identify the mechanism by which SbSbS4 functioned when used as a lubricant in the dry powder form and as an additive to oils and greases. Friction and wear behavior of SbSbS^ was investigated using several different wear tests carried out in air at temperatures ranging from 20°C to 500°C.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Nicholaos G. Demas ◽  
Robert A. Erck ◽  
Cinta Lorenzo-Martin ◽  
Oyelayo O. Ajayi ◽  
George R. Fenske

The effect of two nanoparticle oxides on friction and wear was studied under laboratory test conditions using a reciprocating test machine and two test configurations. The addition of these nanoparticles in base stock oil under certain conditions reduced the coefficient of friction and improved wear, but that depended on the test configuration. Examination of the rubbed surfaces showed the pronounced formation of a tribofilm in some cases, while polishing on the surface was also observed in other cases. Contact configuration is important when oxide nanoparticles are being evaluated and the conclusions about their efficacy can be vastly different.


2020 ◽  
Vol 44 (6) ◽  
pp. 498-507
Author(s):  
Tan-Duc NGUYEN ◽  
Xuan-Quang NGO ◽  
Thanh-Luu PHAM ◽  
Thanh-Son DAO

Cyanobacterial blooms often consist of mixtures of microcystin-producing and microcystin-free species, and both can cause unpredictable effects on aquatic organisms. In this work, the subchronic effects of the cyanobacterial crude extracts (CCEs) from microcystin-producing and microcystin-free cyanobacteria with different microcystin concentrations (1, 10, and 50 μgL−1)on Daphnia magna were investigated. The life-history trait responses of D. magna to CCEs were determined based on survival, reproduction, and somatic growth. In addition, the physiological response, represented by the feeding rate of D. magna on green algae (Scenedesmussp.), after exposure to both types of crude extracts was estimated. Our results showed that both microcystin-containing (MCCE) and microcystin-free (NCCE) crude extracts insignificantly reduced survival but strongly enhanced reproduction and somatic growth of organisms. However, degradation of eggs and neonates of the gravid females exposed to CCEs was observed. In addition, the feeding rate of D. magna exposed to MCCE increased significantly, whereas no change in the feeding rate was observed for NCCE-exposed D. magna. In general, new and interesting aspects of the toxicity of MCCE and NCCE were revealed by this study, which contributes to the understanding of the toxicity of Pseudanabaena sp. extract on D. magna under bioassays.


2018 ◽  
Vol 39 (3) ◽  
pp. 170
Author(s):  
Scott Wade ◽  
Linda Blackall

Microbially influenced corrosion (MIC) is a general term for when microbes affect material corrosion processes. The rapid corrosion that can occur due to MIC can cause significant dangers and costs for owners of relevant assets in relation to predicting structural safety, design of new structures and maintenance. Verification and/or prediction that a structure may be subject to MIC is not straightforward and, when metal surfaces are involved, it requires a series of metallurgical, microbiological and chemical tests. A useful part of this testing can be laboratory-based studies of microbial consortium samples from the environment of interest. However, there are no standard guidelines for how to perform such tests. Here we report the results of a preliminary study of laboratory corrosion simulations with biomass from a marine metallic corrosion event and show that simple changes in the test conditions can alter the rate of corrosion and the composition of microbial consortia during the test.


2008 ◽  
Vol 368-372 ◽  
pp. 894-897
Author(s):  
Xian Wu Luo ◽  
Hong Yuan Xu ◽  
Juan Liu ◽  
Long Hao Qi

Slurry pumps are used to transport the liquid fluids with solid particles in the industries. The materials of flow passage in a slurry pump are subjected to severe damage due to abrasive erosion. This paper compares the abrasive erosion for an engineering ceramics i.e. hot pressed Si3N4 ceramics and a high chrome cast iron i.e. Cr26 by laboratory test and industrial operation. The results indicate that the erosion rate of Cr26 is much larger than that of hot pressed Si3N4 ceramics under the same test conditions. That indicates that the engineering ceramics is a promising alternation of the expensive material such as Cr26 in the application of slurry pumps. It is noted that the erosion pattern such as scale ripple has the similar features for both materials, even the hardness of hot pressed Si3N4 ceramics is much higher than Cr26. Further, the scale ripple is suspected to be originated from the relatively weak grain boundary and enhanced by cavitation.


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