Hurricanes alter 10 Be concentrations in tropical river sediment but do not change regional erosion rate estimates

2021 ◽  
Author(s):  
Melinda Quock ◽  
Amanda H. Schmidt ◽  
Lee B. Corbett ◽  
Paul R. Bierman ◽  
Alan J. Hidy ◽  
...  
Keyword(s):  
Erosion Rate ◽  
River Sediment ◽  
Tropical River

scholarly journals Culture-independent study of bacterial communities in tropical river sediment

2016 ◽  
Vol 81 (1) ◽  
pp. 200-209 ◽  
Author(s):  
Honglada Thoetkiattikul ◽  
Wuttichai Mhuantong ◽  
Onruthai Pinyakong ◽  
Worachart Wisawapipat ◽  
Atsushi Yamazoe ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
River Sediment ◽  
Independent Study ◽  
Tropical River ◽  
Culture Independent

scholarly journals Sediment Impact On Turbine Material: Case Study Of Modi River, Nepal

1970 ◽  
Vol 8 (1) ◽  
pp. 88-96 ◽  
Author(s):  
L Poudel ◽  
B Thapa ◽  
BP Shrestha ◽  
NK Shrestha
Keyword(s):  
Weight Loss ◽  
Erosion Rate ◽  
River Sediment ◽  
Turbine Blades ◽  
Average Weight ◽  
Sand Sample ◽  
Rotating Disc ◽  
The Impact ◽  
Total Impact

Hydropower is considered as one of the most economical and stable base energy source compared with other sources of energy of Nepal. Researches coherent to this field are not new but yet it is not sufficient, lots of tiles have to be kept for better understanding of hydropower effecting elements. Sand is the most affecting element that damages the turbine blades, so research on relation of sand and turbine is most. This research is done to find out the impact of sediment on turbine material. Modi River sediment at eight different stations has been taken as sample and its erosion rate in turbine blade sample specimen has been accounted in this study. Rotating disc apparatus has been utilized to find out the total impact of sand on turbine material. Four same kind of test turbine material is used on single rotating disc all at a time at same condition to define sand impact. Thirty gram (gm) of sediment mixed with three liters of water is used to strike sample pieces for five minutes. Two different tests of sediment samples of 8 different locations were studied. After all the test it is observed that the first test sand sample of location 1 and turbine material 1 has the highest impact with a weight loss of 7.764 mg and least impact in sand sample location 1 and sand sample 3 with a weight loss of 3.5 mg. Average weight loss of turbine material in first location is 5.929 mg which is the greatest impact and 4.0083 at eight locations which is the least. Relating to turbine material first rotating disc turbine specimen P0A has been affected highly with weight loss of 9.289 mg and less eroded on P5A rotating turbine specimen with weight loss of 1.2 mg. DOI: http://dx.doi.org/10.3126/kuset.v8i1.6047 KUSET 2012; 8(1): 88-96

GLACIAL EROSION RATE FOR THE CORDILLERAN ICE SHEET IN SOUTHEAST ALASKA USING COSMOGENIC 10BE CONCENTRATIONS IN BEDROCK AND PERCHED BOULDERS

2018 ◽  
Author(s):  
Christopher Sbarra ◽  
◽  
Jason P. Briner ◽  
Alia J. Lesnek ◽  
James F. Baichtal
Keyword(s):  
Erosion Rate ◽  
Ice Sheet ◽  
Glacial Erosion ◽  
Southeast Alaska ◽  
Cordilleran Ice Sheet ◽  
Cosmogenic 10Be

scholarly journals Effect of Nitrogen Ion Implantation on the Cavitation Erosion Resistance and Cobalt-Based Solid Solution Phase Transformations of HIPed Stellite 6

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2324
Author(s):  
Mirosław Szala ◽  
Dariusz Chocyk ◽  
Anna Skic ◽  
Mariusz Kamiński ◽  
Wojciech Macek ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Ion Implantation ◽  
Phase Transformations ◽  
Erosion Rate ◽  
Cavitation Erosion ◽  
Matrix Phase ◽  
Nitrogen Ion Implantation ◽  
Stellite 6 ◽  
Nitrogen Ion

From the wide range of engineering materials traditional Stellite 6 (cobalt alloy) exhibits excellent resistance to cavitation erosion (CE). Nonetheless, the influence of ion implantation of cobalt alloys on the CE behaviour has not been completely clarified by the literature. Thus, this work investigates the effect of nitrogen ion implantation (NII) of HIPed Stellite 6 on the improvement of resistance to CE. Finally, the cobalt-rich matrix phase transformations due to both NII and cavitation load were studied. The CE resistance of stellites ion-implanted by 120 keV N+ ions two fluences: 5 × 1016 cm−2 and 1 × 1017 cm−2 were comparatively analysed with the unimplanted stellite and AISI 304 stainless steel. CE tests were conducted according to ASTM G32 with stationary specimen method. Erosion rate curves and mean depth of erosion confirm that the nitrogen-implanted HIPed Stellite 6 two times exceeds the resistance to CE than unimplanted stellite, and has almost ten times higher CE reference than stainless steel. The X-ray diffraction (XRD) confirms that NII of HIPed Stellite 6 favours transformation of the ε(hcp) to γ(fcc) structure. Unimplanted stellite ε-rich matrix is less prone to plastic deformation than γ and consequently, increase of γ phase effectively holds carbides in cobalt matrix and prevents Cr7C3 debonding. This phenomenon elongates three times the CE incubation stage, slows erosion rate and mitigates the material loss. Metastable γ structure formed by ion implantation consumes the cavitation load for work-hardening and γ → ε martensitic transformation. In further CE stages, phases transform as for unimplanted alloy namely, the cavitation-inducted recovery process, removal of strain, dislocations resulting in increase of γ phase. The CE mechanism was investigated using a surface profilometer, atomic force microscopy, SEM-EDS and XRD. HIPed Stellite 6 wear behaviour relies on the plastic deformation of cobalt matrix, starting at Cr7C3/matrix interfaces. Once the Cr7C3 particles lose from the matrix restrain, they debond from matrix and are removed from the material. Carbides detachment creates cavitation pits which initiate cracks propagation through cobalt matrix, that leads to loss of matrix phase and as a result the CE proceeds with a detachment of massive chunk of materials.

Hydrological connectivity drives the propagule pressure of Limnoperna fortunei (Dunker, 1857) in a tropical river–floodplain system

Hydrobiologia ◽  
2021 ◽  
Vol 848 (9) ◽  
pp. 2043-2053 ◽  
Author(s):  
Vanessa Ernandes de Amo ◽  
Jéssica Ernandes-Silva ◽  
Dieison André Moi ◽  
Roger Paulo Mormul
Keyword(s):  
Propagule Pressure ◽  
Hydrological Connectivity ◽  
Limnoperna Fortunei ◽  
Tropical River ◽  
River Floodplain

Spatio-temporal variation of microplastic along a rural to urban transition in a tropical river

2021 ◽  
pp. 117895
Author(s):  
Hui Ling Chen ◽  
Christopher Neil Gibbins ◽  
Sivathass Bannir Selvam ◽  
Kang Nee Ting
Keyword(s):  
Temporal Variation ◽  
Tropical River ◽  
Urban Transition ◽  
Spatio Temporal

SITE Demonstration of Minergy Glass Furnace Treatment of PCBs, PCDDs/Fs, and Metals in River Sediment

2005 ◽  
Vol 9 (3) ◽  
pp. 158-166 ◽  
Author(s):  
Marta K. Richards ◽  
Kenneth G. Partymiller ◽  
Joseph W. Dauchy ◽  
Kenneth W. Brown
Keyword(s):  
Glass Furnace ◽  
River Sediment ◽  
Furnace Treatment

scholarly journals Co-variation of silicate, carbonate and sulfide weathering drives CO2 release with erosion

2021 ◽  
Vol 14 (4) ◽  
pp. 211-216
Author(s):  
Aaron Bufe ◽  
Niels Hovius ◽  
Robert Emberson ◽  
Jeremy K. C. Rugenstein ◽  
Albert Galy ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Global Climate ◽  
Stream Water ◽  
Sulfide Oxidation ◽  
Silicate Weathering ◽  
Emission Rates ◽  
Mountain Ranges ◽  
Weathering Rates ◽  
Southern Taiwan ◽  
Co2 Release

AbstractGlobal climate is thought to be modulated by the supply of minerals to Earth’s surface. Whereas silicate weathering removes carbon dioxide (CO2) from the atmosphere, weathering of accessory carbonate and sulfide minerals is a geologically relevant source of CO2. Although these weathering pathways commonly operate side by side, we lack quantitative constraints on their co-variation across erosion rate gradients. Here we use stream-water chemistry across an erosion rate gradient of three orders of magnitude in shales and sandstones of southern Taiwan, and find that sulfide and carbonate weathering rates rise with increasing erosion, while silicate weathering rates remain steady. As a result, on timescales shorter than marine sulfide compensation (approximately 106–107 years), weathering in rapidly eroding terrain leads to net CO2 emission rates that are at least twice as fast as CO2 sequestration rates in slow-eroding terrain. We propose that these weathering reactions are linked and that sulfuric acid generated from sulfide oxidation boosts carbonate solubility, whereas silicate weathering kinetics remain unaffected, possibly due to efficient buffering of the pH. We expect that these patterns are broadly applicable to many Cenozoic mountain ranges that expose marine metasediments.

scholarly journals Buoyancy-driven dissolution of inclined blocks: Erosion rate and pattern formation

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Caroline Cohen ◽  
Michael Berhanu ◽  
Julien Derr ◽  
Sylvain Courrech du Pont
Keyword(s):  
Pattern Formation ◽  
Erosion Rate
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