Estimates of Cross-Shore Bedload and Bed Changes

Author(s):  
Zbigniew Pruszak ◽  
Ryszard B. Zeidler
Keyword(s):  
2021 ◽  
Author(s):  
Spyros Pritsis ◽  
Nils Ruther ◽  
Kordula Schwarzwälder ◽  
Anastasios Stamou

<p>Nowadays, the aquatic biodiversity is highly under pressure due to anthropogenic changes of the rivers such hydraulic structures changing the diversity of flow and aquatic fauna as well as sediment continuity. This can have severe consequences on the fish population in the river reach. Fish are strongly depending on a certain substrate composition throughout all their life stages. Juveniles for example are depending on a certain availability of shelter in the substrate in order to survive this stage.</p><p>Therefore, we investigate the effects of changes in the sediment composition at a hydropower plant in Switzerland on the availability of potential shelter for juvenile fish. By utilizing the observed correlation between parameters describing the fine tail of a riverbed’s grain size distribution and shelter abundance for juvenile Atlantic salmon, we predict the available shelter in a river reach by using a 3D hydrodynamic numerical model directly coupled to a morphodynamic model. The initial substrate composition was assumed to be spatially uniform, its parameters based on a grain size distribution curve derived from collected sediment samples.</p><p>This model can now be used for habitat improvement scenario modeling. Based on the assumption that a specific mixture of sediment coming from upstream travelling through the river reach will positively influence the potential shelter availability, different scenarios can be investigated. The baseline for comparison was the simulation of the bed changes without any sediment supply from upstream. The baseline discharge was set to 100 m<sup>3</sup> /s and was applied for 24 hours. The resulting bed changes create a map of the potential shelter availability of this grain size mixture. Then, two scenarios with sediment inflow from the upstream boundary were simulated. One coarse and one fine mixture of sediment were chosen as inputs, with the goal of investigating their impact on shelter abundance. The former designed to have a positive effect while the latter expected to reduce interstitial voids in the substrate and have a negative effect on available shelter.</p><p>The investigation is conducted as part of the EU Horizon 2020 funded project FIThydro (funded under 727830)</p>


2020 ◽  
Vol 205 ◽  
pp. 05016
Author(s):  
Hussein Hashemi Senejani ◽  
Omid Ghasemi-Fare ◽  
Davood Yazdani Cherati ◽  
Fardin Jafarzadeh

Energy piles have been used around the world to harvest geothermal energy to heat and cool residential and commercial buildings. In order to design energy geo-structures, thermo-mechanical response of the geothermal pile must be carefully understood. In this paper, a small scale physical model is designed and a series of heating thermal cycles with various vertical mechanical loads are performed. The instrumented pile is installed inside a dry sand bed. Changes in pile head displacement, shaft strains and pile and sand temperatures are monitored using an LVDT, strain gauges and thermocouples, respectively. Prolonged heating cycles, which would continue until boundary temperature changes, would allow the investigation of excessive heat injection when service loads are active on the pile. The thermal response is discussed including confirmation of a temperature influence zone around the pile, the increase in soil temperature, and minimum vertical heat dispersion in the soil. The mechanical response includes plastic settlements when the vertical load passes 20% of ultimate capacity. Plastic settlements have been observed at the half of the capacity reported for the shorter thermal cycles in similar models. The decrease in the capacity indicates a reduction in elastic response of the soil during longer thermal cycles.


2017 ◽  
Vol 4 (Suppl 2) ◽  
pp. s14-s14
Author(s):  
Melanie Nana ◽  
Tessa Davies ◽  
Beshlie Richards ◽  
Hannah Cranch ◽  
Ruth Alcolado ◽  
...  

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e11524-e11524 ◽  
Author(s):  
S. E. Waintraub ◽  
V. Tuchman

e11524 Background: Neoadjuvant Rx has been shown to downstage locally advanced breast cancer (LABC) to try to achieve a pathological complete response(PCR) and to convert mastectomy to lumpectomy. Bevacizumab (B) was recently approved to treat metastatic breast cancer in combination with paclitaxel (P). NSABP B-27 used preoperative doxorubicin(A) with cyclophosphamide (C) +- docetaxel (Doc) every 3 wks in primary operable breast cancer, yielding a 12.9% PCR with no residual invasive cancer from AC and 26.1% with the addition of Doc. Based on the success of E2100 with P+B over P, and the more recent AVADO trial showing the superiority of B and Doc over Doc, we have treated such Her2neu-neg pts using Doc/B followed by AC/B with a dose dense every (q) 2 week regimen to see if we could achieve a higher PCR rate and to assess the tolerability of this regimen. Methods: Pts with Her2neu-negative locally advanced operable M0 breast cancer were treated initially with B 10mg/kg iv q 2w with Doc 100mg/m2 q 2w four times with pegfilgrastim given 24 hours after chemotherapy, followed by A 60mg/m2 and C 600mg/m2 q 2 weeks four 4 times with pegfilgrastim given 24 hours after chemotherapy with B 10mg/kg iv for the first AC course as the B was discontinued at least 6 weeks prior to definitive breast surgery. All pts were to get radiation therapy after surgery and appropriate anti-estrogen Rx if estrogen receptor was positive. Results: 15 Her-2 neg women aged 35–61 were treated from 9/06-present for locally advanced primary operable breast cancer. All pts had clinically significant tumor reduction. Of the first 12 post-operative evaluable pts that have completed all the pre- operative therapy, the results showed 5 PCR, including one pt with residual sub-cm DCIS, 7 pathological incomplete responses, yielding a 42% PCR. 3 of the 5 PCR pts had lumpectomies. The major toxicity was excessive eye tearing, nail bed changes and lethargy. Conclusions: This novel dose dense q 2 week regimen is safe, tolerable and effective in LABC with acceptable toxicity. The addition of B to dose dense traditional neoadjuvant chemotherapy seems to increase the PCR. Larger prospective trials using B with dose dense therapy are warranted. No significant financial relationships to disclose.


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