Sediment displacement evolution after dam removal in a mountain river (Oioki dam, Leitzaran River)

2021 ◽  
Author(s):  
J. Horacio García ◽  
Askoa Ibisate ◽  
Iban Sánchez-Pinto ◽  
Daniel Vázquez-Tarrío ◽  
Alfredo Ollero ◽  
...  
Keyword(s):  
Grain Size ◽  
Dam Removal ◽  
Second Phase ◽  
Critical Discharge ◽  
Downstream Reach ◽  
Field Campaigns ◽  
Bedload Sediment ◽  
Two Phases ◽  
Lower Discharge ◽  
Discharge Note

<p>Bedload sediment transport was monitored from 2016 to 2020 in the Leitzaran River, in a reach affected by the removal of 7-meters high dam (Oioki dam). The removal was accomplished in two phases, the 3 first meters were removed in September 2018 and the second phase (September 2019) involved the removal of the remaining 4 meters. The study area was divided into three subreaches: control (unaffected by the dam), upstream and downstream of the dam. A sample of 300 RFID-tagged stones were seeded every year (100 at each reach).. Prior to this, the grain-size distribution of the surface sediment was characterized using the Wolman method. Then, the grain-size chosen for the tracer stones was distributed according to three Wentworth intervals: that corresponding to the surface d<sub>50</sub>, d<sub>50</sub>+1 (immediate upper interval), and d<sub>50</sub>-1 (immediate lower interval). It was not possible to follow completely, and the lower interval had to be dismissed as the sediment was very small or narrow to insert the tracer.</p><p>We conducted an extensive surveying field campaign every summer.</p><p>The number of retrieved tracers was relatively high, around 40-70% (considering all field campaigns), although with differences amongst the different sub-reaches. The obtained results were organized by displacements and volumes of sediment moved. The maximum (3,500 meters) and higher mean displacement (~1,550 meters) were registered in the hydrologic year 2019/20. These values are from the upstream reach of the dam and match simultaneously with (i) the whole removal of the dam, and (ii) the period showing a lower discharge (note the critical discharge for the movement of our particles is ~25-30 m<sup>3</sup>·s<sup>-1</sup> (d<sub>50</sub> = 64.0≥Ø<90.5 mm); mean discharge and peak flow from 2013 to 2020 were ~5.3 m<sup>3</sup>·s<sup>-1</sup> and ~125.0 m<sup>3</sup>·s<sup>-1</sup>, respectively and at the end of the watershed).</p><p>We also estimated the bulk bedload volumes during the time spanned by this research and we report how the hydrologic year 2019/20 was the more active in terms of displaced volumes, moving up to 27,500 tons in the upstream reach. In fact, this year also presents the maximum for the downstream reach.</p><p>At this moment, besides the raw data of displacements and volumes, our observations highlight how the fact that a copious load of sediment was made available with the dam removal seemed to be more determinant than the magnitude of the flow to get larger tracer displacements.</p>

scholarly journals Revisiting the Paleo Elbe Valley: Reconstruction of the Holocene, Sedimentary Development on Basis of High-Resolution Grain Size Data and Shallow Seismics

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 505
Author(s):  
Svenja Papenmeier ◽  
H. Christian Hass
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Storm Event ◽  
Second Phase ◽  
The North ◽  
Shallow Seismic ◽  
Scandinavian Ice Sheet ◽  
Western Shore ◽  
Two Phases ◽  
Seismic Reflectors

The Paleo Elbe Valley is the most prominent subsurface structure in the southern North Sea. During the Weichselian (marine isotope stage (MIS) 2), the valley traversed the exposed sea floor and drained the southern margin of the Scandinavian ice sheet. Today the valley is filled with up to 16 m thick sediments, but the responsible processes and drivers remain unknown. To unravel these processes and describe the valley’s evolution with Holocene transgression, we use shallow seismic data and vertical high-resolution grain-size core data. At the base of the western shore, supralittoral fine sands are overlain by a thin layer of clay dated to 9.8 cal. ka BP. The major sediment package consists of marine silt with internal seismic reflectors inclined in a northeastern direction, indicating a sediment transport from the southwest. The valley infill started when the western shore was flooded around 9.6 cal. ka BP and can be divided into two phases. During the first one (9.6–8.1 cal. ka BP) the sedimentation rate was highly driven by wind and waves. The second phase (8.1–5.0 cal. ka BP) was mainly tidal dominated but shows also storm event deposits in the north. Around 5.0 cal. ka BP the valley was almost filled.

Microstructural Kinetics in Alloys Undergoing Transmutations: Application to Aic Neutron Absorbers

1996 ◽  
Vol 439 ◽  
Author(s):  
C. Desgranges ◽  
G. Martin ◽  
F. Defoort
Keyword(s):  
Grain Size ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Second Phase ◽  
Phase Precipitation ◽  
Water Reactors ◽  
Two Phases ◽  
Control Rods ◽  
Kinetics Of

AbstractWhenever an alloy changes composition because of metal to metal transmutations, as is the case in Ag-In-Cd alloys undergoing (n, −) actions in the control rods of Pressurised Water Reactors, unique features may develop.A simple model shows that in a two components alloy more than two phases can coexist under appropriate irradiation conditions i.e. temperature, which scales diffusivities and solubilities, and flux, which scales the transmutations rate; because second phase precipitation occurs at the grain boundaries, the grain size in the underlying matrix is found to be one important parameter of the process.The above ideas are illustrated on a multicomponent alloy, the thermodynamics and the kinetics of which are treated at the same level of sophistication in a mean field approximation.

Structure of second phases in TiAl alloys containing Cr and B

1991 ◽  
Vol 49 ◽  
pp. 576-577
Author(s):  
Ernest L. Hall ◽  
Shyh-Chin Huang
Keyword(s):  
Grain Size ◽  
Second Phase ◽  
Structure And Properties ◽  
Tial Alloys ◽  
Second Phases ◽  
Interstitial Elements

Addition of interstitial elements to γ-TiAl alloys is currently being explored as a method for improving the properties of these alloys. Previous work in which a number of interstitial elements were studied showed that boron was particularly effective in refining the grain size in castings, and led to enhanced strength while maintaining reasonable ductility. Other investigators have shown that B in γ-TiAl alloys tends to promote the formation of TiB2 as a second phase. In this study, the microstructure of Bcontaining TiAl alloys was examined in detail in order to describe the mechanism by which B alters the structure and properties of these alloys.

Accurate Detection and Quantization of Leaf- Diseases through Soft Computing

2018 ◽  
Vol 1 (1) ◽  
pp. 236-247
Author(s):  
Divya Srivastava ◽  
Rajitha B. ◽  
Suneeta Agarwal
Keyword(s):  
Machine Learning ◽  
Image Processing ◽  
Agricultural Production ◽  
Bacterial Blight ◽  
Early Stage ◽  
Second Phase ◽  
Computationally Efficient ◽  
Stage Of Disease ◽  
Accurate Detection ◽  
Two Phases

Diseases in leaves can cause the significant reduction in both quality and quantity of agricultural production. If early and accurate detection of disease/diseases in leaves can be automated, then the proper remedy can be taken timely. A simple and computationally efficient approach is presented in this paper for disease/diseases detection on leaves. Only detecting the disease is not beneficial without knowing the stage of disease thus the paper also determine the stage of disease/diseases by quantizing the affected of the leaves by using digital image processing and machine learning. Though there exists a variety of diseases on leaves, but the bacterial and fungal spots (Early Scorch, Late Scorch, and Leaf Spot) are the most prominent diseases found on leaves. Keeping this in mind the paper deals with the detection of Bacterial Blight and Fungal Spot both at an early stage (Early Scorch) and late stage (Late Scorch) on the variety of leaves. The proposed approach is divided into two phases, in the first phase, it identifies one or more disease/diseases existing on leaves. In the second phase, amount of area affected by the disease/diseases is calculated. The experimental results obtained showed 97% accuracy using the proposed approach.

Representação e simbolismo: artes visuais na fronteira Brasil/Bolívia

2020 ◽  
Vol 4 (3) ◽  
pp. 286
Author(s):  
Paulo César Antonini de Souza ◽  
Derick Trindade Bezerra
Keyword(s):  
Visual Arts ◽  
Social Order ◽  
Research Field ◽  
Border Region ◽  
Second Phase ◽  
Two Dimensional ◽  
Santa Cruz ◽  
Cultural Conditions ◽  
Two Phases ◽  
America Latina

ResumoTendo por campo de investigação o Festival da América do Sul Pantanal (FASP) em 2018, na cidade de Corumbá (Brasil), objetiva-se identificar a materialidade e conceitos que permeiam as manifestações artísticas bidimensionais nesta região de fronteira, a partir da percepção de artistas da Bolívia. A pesquisa se organizou em duas fases: na primeira foi realizado um levantamento em plataformas online de produções acadêmicas em artes visuais, com foco no trabalho bidimensional, utilizando os descritores “arte popular” e “estética latina” resultando em três artigos. Na segunda fase foram selecionados dois trabalhos de uma artista da Bolívia, participante da mostra “Conexão Santa Cruz”, realizada durante o FASP 2018, que foram analisados em seus níveis representacional e simbólico. Pela interpretação das imagens foi possível construir uma leitura sobre a perspectiva da artista a respeito de suas condições culturais dentro da ordenação social em que se encontra situada.Palavras-chave: Artes Visuais. Arte Popular. Arte Regional. América Latina. Representation and symbolism: visual arts on the Brazil/Bolivia frontierAbstractHaving as research field the Festival da América do Sul Pantanal (FASP) in 2018, in the city of Corumbá (Brazil), the objective is to identify the materiality and concepts that permeate the two-dimensional artistic manifestations in this border region, from the perception of artists from Bolivia. The research was organized in two phases: in the first, a survey was carried out on online platforms of academic productions in visual arts, focusing on two-dimensional work, using the descriptors “arte popular” and “estética latina” resulting in three articles. In the second phase, two works were selected by an artist from Bolivia, participating in the exhibition “Conexão Santa Cruz”, held during FASP 2018, which were analyzed at their representational and symbolic levels. Through the interpretation of the images, it was possible to construct a reading on the artist’s perspective regarding her cultural conditions within the social order in which she is located.Keywords: Visual Arts. Folk Art. Regional Art. Latin America.Representación y simbolismo: artes visuales en la frontera de Brasil/BoliviaResumenTeniendo como campo de investigación el Festival de Sudamérica Pantanal (FASP) en 2018, en la ciudad de Corumbá (Brasil), el objetivo es identificar la materialidad y conceptos que permean las manifestaciones artísticas bidimensionales en esta región fronteriza, desde la percepción de artistas de Bolivia. La investigación se organizó en dos fases: en la primera, se realizó una encuesta en plataformas online de producciones académicas en artes visuales, con foco en el trabajo bidimensional, utilizando los descriptores “arte popular” y “estética latina” dando como resultado tres artículos. En la segunda fase, dos obras fueron seleccionadas por un artista de Bolivia, participante de la exposición “Conexão Santa Cruz”, realizada durante FASP 2018, que fueron analizadas en sus niveles representativos y simbólicos. A través de la interpretación de las imágenes, fue posible construir una lectura sobre la perspectiva de la artista sobre sus condiciones culturales dentro del orden social en el que se ubica.Palabras clave: Artes Visuales. Arte Popular. Arte Regional. América Latina.

scholarly journals Development and validation of a short version of the Sarcopenia Quality of Life questionnaire: the SF-SarQoL

2021 ◽  
Author(s):  
A. Geerinck ◽  
C. Beaudart ◽  
J.-Y. Reginster ◽  
M. Locquet ◽  
C. Monseur ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Short Form ◽  
Reduction Process ◽  
Community Dwelling ◽  
Short Version ◽  
Second Phase ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
Two Phases

Abstract Purpose To facilitate the measurement of quality of life in sarcopenia, we set out to reduce the number of items in the previously validated Sarcopenia Quality of Life (SarQoL®) questionnaire, and to evaluate the clinimetric properties of this new short form. Methods The item reduction process was carried out in two phases. First, information was gathered through item-impact scores from older people (n = 1950), a Delphi method with sarcopenia experts, and previously published clinimetric data. In the second phase, this information was presented to an expert panel that decided which of the items to include in the short form. The newly created SFSarQoL was then administered to older, community-dwelling participants who previously participated in the SarcoPhAge study. We examined discriminative power, internal consistency, construct validity, test–retest reliability, structural validity and examined item parameters with a graded response model (IRT). Results The questionnaire was reduced from 55 to 14 items, a 75% reduction. A total of 214 older, community-dwelling people were recruited for the validation study. The clinimetric evaluation showed that the SF-SarQoL® can discriminate on sarcopenia status [EWGSOP2 criteria; 34.52 (18.59–43.45) vs. 42.86 (26.56–63.69); p = 0.043], is internally consistent (α = 0.915, ω = 0.917) and reliable [ICC = 0.912 (0.847–0.942)]. A unidimensional model was fitted (CFI = 0.978; TLI = 0.975; RMSEA = 0.108, 90% CI 0.094–0.123; SRMR = 0.055) with no misfitting items and good response category separation. Conclusions A new, 14-item, short form version of the Sarcopenia Quality of Life questionnaire has been developed and shows good clinimetric properties.

scholarly journals SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kui Xu ◽  
Ming Zhang ◽  
Jie Liu ◽  
Nan Sha ◽  
Wei Xie ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Performance Optimization ◽  
Power Transmission ◽  
Base Station ◽  
Second Phase ◽  
Wireless Power ◽  
Half Duplex ◽  
Non Linear ◽  
Two Phases ◽  
And Performance

Abstract In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.

scholarly journals Development and Evaluation of Direct Paddy Seeder in Puddled Field

2021 ◽  
Vol 13 (5) ◽  
pp. 2745
Author(s):  
Manoj Kumar ◽  
Ritu Dogra ◽  
Mahesh Narang ◽  
Manjit Singh ◽  
Sushant Mehan
Keyword(s):  
Laboratory Testing ◽  
Field Evaluation ◽  
Row Spacing ◽  
Second Phase ◽  
Cell Type ◽  
Inclined Plate ◽  
Seed Damage ◽  
Two Phases ◽  
Almost All ◽  
Different Soils

Manual transplanting, a pre-dominant practice in almost all the paddy growing areas in India, is laborious, burdensome, and has many expenses on raising, settling, and transplanting nursery. The transplanting process’s limitations motivated the replacement of conventional paddy transplanting methods. The study was divided into two phases. The first phase included laboratory testing of three levels of metering mechanisms, namely cell type (M1) with 10 cells grooved around a circular plate having a 13 cm diameter, inclined plate (M2) containing 24 U shaped cells provided on an 18 cm diameter plate, and fluted roller (M3) with 10 flutes on a 5 cm diameter shaft. The testing matrix included a missing index, multiple index, and seed damage with forward speeds (2.5, 3.0, and 3.5 km/h), and pre-germination levels of 24 h soaked (P1), 24 h pre-germinated (P2), and 36 h pre-germinated paddy seeds (P3)). The second phase included selecting the best combination obtained from the laboratory study and developing a new efficient planter for the puddled field. The inclined plate metering mechanism operating at 2.5 km/h for 24 h pre-germinated seeds was reported most efficient from the first phase. Therefore, a self-propelled 8-row planter equipped with an inclined plate metering mechanism having a row-to-row spacing of 22.5 cm was developed, fabricated, and evaluated in the puddled field. The designed planter was assessed on two different soils: sandy loom (ST1) and clay loom (ST2) and at two different hopper fill levels as ½ filled hopper (F1) and ¾ filled hopper (F2). The number of plants per square meter and hill-to-hill spacing was measured. The on-field evaluation revealed that the number of plants per square meter was non-significantly affected by the type of soil but was significantly affected by hopper fill.

scholarly journals XCOVNet: Chest X-ray Image Classification for COVID-19 Early Detection Using Convolutional Neural Networks

2021 ◽  
Author(s):  
Vishu Madaan ◽  
Aditya Roy ◽  
Charu Gupta ◽  
Prateek Agrawal ◽  
Anand Sharma ◽  
...  
Keyword(s):  
Image Classification ◽  
Second Phase ◽  
Two Phase ◽  
X Ray ◽  
The Neural Network ◽  
Rapid Spread ◽  
Chest X Ray ◽  
Polymerase Chain ◽  
Two Phases ◽  
Active Patients

AbstractCOVID-19 (also known as SARS-COV-2) pandemic has spread in the entire world. It is a contagious disease that easily spreads from one person in direct contact to another, classified by experts in five categories: asymptomatic, mild, moderate, severe, and critical. Already more than 66 million people got infected worldwide with more than 22 million active patients as of 5 December 2020 and the rate is accelerating. More than 1.5 million patients (approximately 2.5% of total reported cases) across the world lost their life. In many places, the COVID-19 detection takes place through reverse transcription polymerase chain reaction (RT-PCR) tests which may take longer than 48 h. This is one major reason of its severity and rapid spread. We propose in this paper a two-phase X-ray image classification called XCOVNet for early COVID-19 detection using convolutional neural Networks model. XCOVNet detects COVID-19 infections in chest X-ray patient images in two phases. The first phase pre-processes a dataset of 392 chest X-ray images of which half are COVID-19 positive and half are negative. The second phase trains and tunes the neural network model to achieve a 98.44% accuracy in patient classification.

scholarly journals A Separated Reset Waveform Design for Suppressing Oil Backflow in Active Matrix Electrowetting Displays

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 491
Author(s):  
Linwei Liu ◽  
Pengfei Bai ◽  
Zichuan Yi ◽  
Guofu Zhou
Keyword(s):  
Experimental Data ◽  
Dielectric Layer ◽  
Waveform Design ◽  
Second Phase ◽  
Active Matrix ◽  
Two Phases ◽  
Back Stage ◽  
A Charge ◽  
Electric Field Force ◽  
Driving Waveform

The electrowetting display (EWD) is a kind of reflective paper-like display. Flicker and grayscale distortion are caused by oil backflow, which is one of the important factors restricting the wide application of EWDs. The charge embedding caused by the electric field force in the dielectric layer is the cause of oil backflow. To suppress oil backflow, a separated reset waveform based on the study of oil movement is proposed in this paper. The driving waveform is divided into two parts: a reset waveform and a grayscale waveform. The reset waveform generated by a reset circuit can be used to output various voltages. The grayscale waveform is set as a traditional PWM waveform. The reset waveform is composed of a charge-releasing stage and oil-moving back stage. Two phases are contained in the charge releasing stage. The overdriving voltage is used during the first phase to reverse the voltage of all pixels. The trapped charges can then be released from the dielectric layer during the second phase. A higher voltage is used during the oil-moving back stage to drive the oil faster in the pixel. By comparing the experimental data, the oil backflow time is extended 761 times by the reset waveform. The four grayscales can be maintained by the reset waveform after driving for 300 s.

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