A closer look at sedimentation processes in two dam reservoirs

2021 ◽  
pp. 127397
Author(s):  
Jan Sedláček ◽  
Ondřej Bábek ◽  
Tomáš Matys Grygar ◽  
Zuzana Lenďáková ◽  
Jan Pacina ◽  
...  
Keyword(s):  
Dam Reservoirs ◽  
Sedimentation Processes

Effects of Pool Drawdown and Wing Dams (Pool 8), and Closure Damns (Pool 13), on Navigation Channel Sedimentation Processes, Upper Mississippi River

2006 ◽  
Author(s):  
David D. Abraham ◽  
Mark A. Cowan ◽  
Jon S. Hendrickson ◽  
William M. Katzenmeyer ◽  
Kevin J. Landwhr ◽  
...  
Keyword(s):  
Mississippi River ◽  
Upper Mississippi River ◽  
Navigation Channel ◽  
Sedimentation Processes

Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Surface Morphology ◽  
Average Diameter ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Sedimentation Processes

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>

Land-building and Stabilization by Mangroves

1974 ◽  
Vol 1 (4) ◽  
pp. 285-294 ◽  
Author(s):  
Jedfrey M. Carlton
Keyword(s):  
Cold Hardiness ◽  
Current Data ◽  
Saline Environment ◽  
Central Florida ◽  
Housing Developments ◽  
Red Mangrove ◽  
Mangrove Seedlings ◽  
Wall Construction ◽  
Sea Wall ◽  
Sedimentation Processes

Covering broad areas of tropical shorelines are unique plants known as mangroves, which exhibit several structural and physiological modifications to the saline environment—especially in their root systems. Prop-roots and pneumatophores, two obvious modifications, allow mangroves to play a role in coastal geomorphology, either as land-builders or as stabilizers of substrates derived from classical sedimentation processes.Current data show that: (1) Provided with proper substrates, mangrove seedlings can be raised in the laboratory for later planting in the field, although on exposed beaches success ratios may be low. (2) Larger mangrove plants (1.0–5.0 m in height) may be transplanted with relative ease and appear to succeed with few or no mortalities resulting from the techniques used. (3) Pruning of mangroves appears to be a successful method of mangrove control, allowing their utilization for stabilization around housing developments. (4) Fossil evidence for mangroves as shoreline developers is suggested by the discovery of a fossil mangrove reef off the Miami, Florida, coast. However, submergence of near-by mangrove areas has occurred, as evidenced by sea-grass beds growing above buried peat in the bay bottom. (5) Black Mangroves may be more useful than Red Mangroves as shoreline stabilizers due to their cold-hardiness, ability to tolerate disturbed substrates, and rapid production of pneumatophores. (6) Insect and isopod damage to mangroves has been documented, and it has been suggested by several research workers that such damage may lead to increased erosion of coastlines in many areas of southern and central Florida. In addition, boring activities in Red Mangrove seedlings may result in decreased numbers of seedlings being available for new mangrove growth and colonization. (7) Mangroves have been suggested for use as stabilizers of substrates in conjunction with planned filling and sea wall construction.

scholarly journals Sedimentation processes and sedimentary characteristics of tidal bores along the north bank of the Qiantang Estuary

2012 ◽  
Vol 57 (13) ◽  
pp. 1578-1589 ◽  
Author(s):  
DaiDu Fan ◽  
GuoFu Cai ◽  
Shuai Shang ◽  
YiJing Wu ◽  
YanWei Zhang ◽  
...  
Keyword(s):  
Sedimentary Characteristics ◽  
The North ◽  
Tidal Bores ◽  
North Bank ◽  
Sedimentation Processes

Effect on Sedimentation Characteristics of Bentonite Suspension at Different Conditions

2013 ◽  
Vol 333-335 ◽  
pp. 2004-2009
Author(s):  
Lin Ling Jiang ◽  
Wei Mo ◽  
Xiao Jing Yang ◽  
Tian Li Xue ◽  
Shao Jian Ma
Keyword(s):  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Sodium Pyrophosphate ◽  
Sedimentation Rates ◽  
Sedimentation Analysis ◽  
Ph Values ◽  
Bentonite Suspension ◽  
Sedimentation Time ◽  
Sedimentation Processes

To better understand the sedimentation processes of bentonite, the sedimentation characteristic of bentonite suspension was studied by using the sedimentation analysis module of Dynamic Contact Angle Meter and Tensiometer. The results indicated that sedimentation characteristics of bentonite suspension were affected by the concentration and pH values of the suspension together with the dosage of dispersants. The natural sedimentation rates of bentonite suspension declined firstly with prolonging the sedimentation time and soon stabilized after about 50s. The sedimentation weight of particles hardly changed when the concentration ranged from 0.5% to 5.0%, while it increased significantly when ranged from 5.0% to 10.0%. The sedimentation weight and rate were relatively bigger at 4.4, 11.8 than that of 6.0, 7.9, and the maximum values appeared at pH11.8. Adding sodium pyrophosphate could improve the dispersibility of bentonite suspension.

scholarly journals Soil Formation, Subaerial Sedimentation Processes and Ancient Cultures during MIS 2 and the Deglaciation Phase MIS 1 in the Baikal–Yenisei Siberia (Russia)

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 323
Author(s):  
Galina Vorobieva ◽  
Nadezhda Vashukevich ◽  
Natalia Berdnikova ◽  
Ivan Berdnikov ◽  
Dmitry Zolotarev ◽  
...  
Keyword(s):  
Soil Formation ◽  
Climatic Conditions ◽  
Initial Profile ◽  
Formation Type ◽  
Cultural Layers ◽  
Human Habitation ◽  
Soil Forming Processes ◽  
First Time ◽  
Sedimentation Processes ◽  
Humus Horizons

The time of Sartan glaciation in the Baikal–Yenisei Siberia, is comparable with that of MIS 2 and the deglaciation phase MIS 1. Loess loams, aeolian–colluvial sands and sandy loams represent subaerial sediments. There are four subhorizons (sr1, sr2, sr3 and sr4) in the Sartan horizon (sr). Sedimentary and soil-forming processes at different stratigraphic levels are considered. Differing soil formation types of cold periods are distinguished. Soils of the interstadial type with the A-C profile are represented only in the Early Sartan section of this paper. The soils of the pleniglacial type are discussed throughout the section. Their initial profile is O-C, TJ-C and W-C. Plant detritus remnants or poor thin humus horizons are preserved in places from the upper horizons. We propose for the first time for the interphasial soil formation type of cold stages to be distinguished. This is represented in the sections by the preserved BCm, BCg, Cm and Cg horizons of 15–20 cm thick. The upper horizons are absent in most sections. According to the surviving fragments, these were organogenous (O, TJ and T) and organomineral (AO and W) horizons. The sedimentation and soil formation features are considered from the perspective reconstruction of the Sartan natural and climatic conditions. Buried Sartan soils often contain cultural layers. Soil formation shows a well-defined periodicity of natural condition stabilization, which allowed ancient populations to adapt actively to various situations. Archaeologists’ interest in fossil soils is based on the ability of soils to “record” information about the natural and climatic conditions of human habitation.

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