scholarly journals SUSPENDED LOAD CALCULATIONS IN A TIDAL ESTUARY

1970 ◽  
Vol 1 (12) ◽  
pp. 117
Author(s):  
Brian A. O'Connor
Keyword(s):  
Salinity Gradient ◽  
Coarse Sand ◽  
Gradient Term ◽  
Sediment Distribution ◽  
Tidal Estuary ◽  
Fine Grained ◽  
Sediment Size ◽  
Starting Point ◽  
The Vertical Distribution ◽  
Distribution Equation

The present work describes the derivation of equations which can represent the vertical distribution of sediment in a well mixed tidal estuary The starting point for the analysis is the two dimensional longitudinal equation of motion, including the longitudinal salinity gradient term Equations are given which represent a steady state sediment profile and it is shown that these are similar to the expression used in urn-directional flow e g Rouse's equation It is argued that the derived equations could be applied to a real estuary, subject to certain restrictions on sediment size and estuary type An application of the theoretical equations to the Mersey Estuary indicates reasonable agreement between observed and predicted sediment quantities for medium and coarse sand particles Agreement is shown to be worst for fine grained sediments and it is concluded that much better results can be obtained by using the non-steady one dimensional sediment distribution equation in discrete steps throughout the tidal cycle.

scholarly journals ANNUAL CHANGES OF BEACH PROFILE AND NEARSHORE SEDIMENT DISTRIBUTION OFF DUNGUN-KEMAMAN,TERENGGANU, MALAYSIA

2018 ◽  
Vol 80 (5) ◽  
Author(s):  
Rosnan Yaacob ◽  
Hasrizal Shaari ◽  
Noraisyah Sapon ◽  
Mohd Fadhli Ahmad ◽  
Effi Helmi Arifin ◽  
...  
Keyword(s):  
Surf Zone ◽  
River Mouth ◽  
Coarse Sand ◽  
Sediment Distribution ◽  
Proper Understanding ◽  
Sediment Size ◽  
Dominant Component ◽  
Beach Processes ◽  
Mean Size ◽  
One Year

A proper understanding of beach processes must include the adjacent shallow marine waters or nearshore environment. This paper focused on the sedimentological and morphological investigation of Terengganu coastal area stretch lies between Dungun and Kemaman. The study area comprised five beaches and 36 nearshore stations. The present investigation attempts to study the time variation of the grain-size along the coast and in order to observe one-year cycle of the perpendicular profile of the beach. Teluk Lipat beach faced a huge modification compared to other beaches. The severely-eroded beaches in the study area characterized by coarse sand. Sediments from backshore and upper beach zone decreased in mean size and became poorly sorted towards surf zone area. Meanwhile, superficial sediment distribution of nearshore area revealed that silt is the most dominant component and the sediment size became coarser towards the shoreline. The results favor an alternative explanation, indicating that the river is the main source for the coastal sands, which are probably reworked by longshore currents on opposite directions apart from the river mouth, resulting on coastal propagation.

Counting on Carrington Road: Street Numbers as Metonyms of the Urban

2018 ◽  
Vol 17 (4) ◽  
pp. 433-450 ◽  
Author(s):  
Alexandra Crosby ◽  
Kirsten Seale
Keyword(s):  
Visual Presentation ◽  
Creative Industries ◽  
Creative Economy ◽  
Top Down ◽  
Fine Grained ◽  
Creative City ◽  
Starting Point ◽  
Urban Futures ◽  
Post Industrial ◽  
The City

As urban renewal agendas are fortified in cities globally, ‘creativity’ – as contained within discourses of the creative industries, the Creative City and the creative economy – is circulated as the currency of secure post-industrial urban futures. Using the nexus between creativity and the urban as a starting point, the authors investigate how local enterprises visually communicate the urban in a neighbourhood that is characterized by the interface between manufacturing and creative industries. This research takes a fine-grained approach to the notion of creativity through an audit and qualitative analysis of the visual presentation, material attributes and semiotic meaning of street numbers. The authors do this by collecting data on and analysing how street numbers have been made, selected, used, replaced and layered in a contested industrial precinct in Australia’s largest city, Sydney. They contend that street numbers, as a ubiquitous technology within the city that is both operational and creative, are metonyms for what they understand to be urban. In arguing for vernacular readings of the city, they make use of a top-down, governmental mode of reading the city – the operational legibility of street numbering – as an intervention in current discourses of the urban and of creativity in the city.

A Tool for Discourse Analysis and Visualization

2013 ◽  
Vol 5 (2) ◽  
pp. 55-71 ◽  
Author(s):  
Costin-Gabriel Chiru ◽  
Stefan Trausan-Matu
Keyword(s):  
Discourse Analysis ◽  
Intrinsic Structure ◽  
Fine Grained ◽  
Construction Of Knowledge ◽  
Cultural Paradigms ◽  
Starting Point ◽  
Social Construction Of Knowledge ◽  
Before And After ◽  
The Difference ◽  
Polyphonic Model

In this paper the authors present a system that combines the cognitive and socio-cultural paradigms in the field of discourse analysis in order to analyze both texts written by only one author (for example narrations) and those written collaboratively (chat conversations, blogs, wikis, forums). The novelty of their approach is that the majority of the existing applications are oriented on analyzing only one of these two types, an adaptation being necessary for the analysis of the other type. Another advantage of the presented system is that since it is centered on a dialogistic polyphonic model considering topics as inter-animated voices, it could show the difference between coarse- and fine-grained coherence in discourse, therefore allowing the analysis of a text from two different viewpoints: a) its intrinsic structure and cohesion and b) how well this text fits in a stream of texts (whether it is or not cohesive with the texts before and after it). The dialogistic polyphonic model was used as a starting point for a method for analyzing collaboration and social construction of knowledge in groups and communities using textual interactions, and for several implemented systems for providing computerized support to the analysis method through visualizations and feedback generation.

scholarly journals Interpersonal violence and mental health: a social justice framework to advance research and practice

2020 ◽  
Vol 7 ◽  
Author(s):  
W.A. Tol
Keyword(s):  
Mental Health ◽  
Social Justice ◽  
Interpersonal Violence ◽  
Global Mental Health ◽  
Research And Practice ◽  
Fine Grained ◽  
Special Series ◽  
Conceptual Clarity ◽  
Starting Point ◽  
Social Justice Theory

Abstract This editorial paper accompanies a special series in the journal Global Mental Health focused on the topic of interpersonal violence and mental health. This series included 24 papers reporting on data from 31 countries, published between 2017 and 2019. This accompanying paper provides a short summary of findings in the special series and reflects on next steps in research and practice. Collectively, the series’ 24 papers suggest intricate bi-directional relationships between interpersonal violence and mental health, situated in particular contexts and varying across the life course. In order to study this complexity, an overarching theoretical framework is critical. This paper takes the social justice theory developed by Powers and Faden (2006, 2019) as a starting point. It is argued that application of this social justice framework will be helpful to: strengthen conceptual clarity; provide a sense of direction for research and practice in the area of interpersonal violence and mental health; assist in conducting more fine grained analyses of contextually determined processes of disadvantage; and help situate disciplinary specific research and practice questions in their broader context, thereby strengthening multi-disciplinary research and multi-sectoral policy and programming efforts.

scholarly journals Universal relation with regime transition for sediment transport in fine-grained rivers

2019 ◽  
Vol 117 (1) ◽  
pp. 171-176 ◽  
Author(s):  
Hongbo Ma ◽  
Jeffrey A. Nittrouer ◽  
Baosheng Wu ◽  
Michael P. Lamb ◽  
Yuanfeng Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Sediment Load ◽  
Yellow River ◽  
Fine Sand ◽  
Sediment Flux ◽  
Universal Relation ◽  
Sediment Grain Size ◽  
Fine Grained ◽  
Predictive Algorithm ◽  
Sediment Size

Fine-grained sediment (grain size under 2,000 μm) builds floodplains and deltas, and shapes the coastlines where much of humanity lives. However, a universal, physically based predictor of sediment flux for fine-grained rivers remains to be developed. Herein, a comprehensive sediment load database for fine-grained channels, ranging from small experimental flumes to megarivers, is used to find a predictive algorithm. Two distinct transport regimes emerge, separated by a discontinuous transition for median bed grain size within the very fine sand range (81 to 154 μm), whereby sediment flux decreases by up to 100-fold for coarser sand-bedded rivers compared to river with silt and very fine sand beds. Evidence suggests that the discontinuous change in sediment load originates from a transition of transport mode between mixed suspended bed load transport and suspension-dominated transport. Events that alter bed sediment size near the transition may significantly affect fluviocoastal morphology by drastically changing sediment flux, as shown by data from the Yellow River, China, which, over time, transitioned back and forth 3 times between states of high and low transport efficiency in response to anthropic activities.

scholarly journals Análise Montante-Jusante da Granulometria dos Sedimentos de Fundo e Suspenso do Rio Negro e Tributários (Bacia Amazônica, Brasil)

2021 ◽  
Vol 14 (2) ◽  
pp. 997
Author(s):  
Rogério Ribeiro Marinho ◽  
Antonio Fábio Sabbá Guimarães Vieira ◽  
Feliciano De Souza Maciel
Keyword(s):  
Sediment Transport ◽  
River Basin ◽  
Amazon Basin ◽  
Suspended Sediments ◽  
Fine Sand ◽  
Large River ◽  
Coarse Sand ◽  
Sediment Size ◽  
Negro River ◽  
Rio Negro

O conhecimento das características físicas de sedimentos transportados por grandes sistemas fluviais possui significativa importância para o entendimento de processos geomorfológicos e hidrológicos. O nível de conhecimento dos grandes sistemas fluviais da Amazônia e sua relação com o transporte de sedimentos ainda é limitado, resultando em lacunas de conhecimento sobre a dinâmica da paisagem nesta complexa região. Este trabalho teve como objetivo avaliar a distribuição espacial da granulometria de sedimentos de fundo e suspenso do Rio Negro e tributários. Realizou-se análise da distribuição do tamanho dos sedimentos em seções amostrais localizadas no alto, médio e baixo curso do Rio Negro. Os resultados da análise granulométrica da carga de fundo indicam a predominância de sedimentos com tamanho variando de 0,25 a 1,0 mm (principalmente areia fina, areia média e areia grossa) enquanto no baixo curso as amostram oscilaram de areia fina a partículas lamosas (< 0,50 mm). No Rio Negro os sedimentos suspensos são compostos principalmente de partículas finas de silte (90% menor que 80 µm) com diâmetro mediano (D50) de 25 µm. As características granulométricas apresentadas neste trabalho fornecem subsídios para o entendimento de processos hidrodinâmicos de transporte e deposição dos sedimentos de fundo e suspenso neste gigante sistema fluvial.    Upstream-downstream Granulometry Analysis of bed and suspended sediments in the Negro River Basin (Amazon Basin, Brazil)A B S T R A C TThe knowledge of the physical characteristics of sediments transported by large river systems has significant importance for the understanding of geomorphological and hydrological processes. The level of knowledge of the large rivers of the Amazon basin and their relationship with sediment transport is limited, resulting in gaps about the dynamics of the landscape in this complex region. This article analyzes the spatial distribution of granulometry of bed and suspended sediments in the Negro River and tributaries. An analysis of the sediment size distribution was carried out in sample sections located in the upper, middle and lower reaches of the Negro River. The results of the granulometric analysis of the bed load indicate the predominance of sediments with sizes ranging from 0.25 to 1.0 mm (mainly fine sand, medium sand and coarse sand) while in the low course they showed oscillated from fine sand to muddy particles (<0.50 mm). In the Negro River basin the suspended sediments are composed mainly of fine silt particles (90% less than 80 µm) with a median diameter (D50) of 25 µm. The granulometric characteristics presented in this work provide subsidies for the understanding of hydrodynamic processes of transport and deposition of bed and suspended sediments in this huge fluvial system.Keywords: sediment transport, Amazon floodplain, multichannel river, anabranching

scholarly journals CHARACTERISTIC OF SEDIMENT AT LEKOK COASTAL WATERS, PASURUAN REGENCY, EAST JAVA

2020 ◽  
Vol 12 (1) ◽  
pp. 235-246
Author(s):  
Rifka Rimbi Anggraini ◽  
Uun Yanuhar ◽  
Yenny Risjani
Keyword(s):  
Coastal Water ◽  
Coastal Waters ◽  
Sandy Loam ◽  
Gravimetric Method ◽  
Open Water ◽  
Silt Loam ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Sediment Size ◽  
Coastal Changes

Sedimentation is one of the dynamics that occur in coastal areas to determine the condition of the coast. Lekok coastal water is one of the open water areas that have very fluctuating dynamics in coastal changes. The structural study of sediment distribution conducted in this location is used to provide information about the process of transportation and sedimentation based on the distribution of sediment grain size. This study aims to determine the horizontal grain sediment size in the Lekok coastal waters. This research was conducted at nine sampling points by sampling in the form of primary sediments randomly using the grab sampler method. Furthermore, further analysis is done by the gravimetric method. Based on the results of the study note that sediments characteristic in Lekok coastal water are generally dominated by three types of sediments, namely: sandy loam, loam, and silt loam. Sorting values ​​are in a well-sorted to the moderately well-sorted condition where the sediment conditions are well sorted. The skewness value is skewed positively, where the value indicates a positive skewed sedimentary condition. The value of kurtosis is in the leptokurtic condition where the sediment from station 1 to station 9 is homogeneous.

scholarly journals Chromosomal rearrangements represent modular cassettes for local adaptation across different geographic scales

2020 ◽  
Author(s):  
Claire Mérot ◽  
Emma Berdan ◽  
Hugo Cayuela ◽  
Haig Djambazian ◽  
Anne-Laure Ferchaud ◽  
...  
Keyword(s):  
Gene Flow ◽  
Local Adaptation ◽  
Environmental Heterogeneity ◽  
Salinity Gradient ◽  
Chromosomal Rearrangements ◽  
Fine Grained ◽  
Varying Environments ◽  
Genomic Regions ◽  
Spatially Varying ◽  
Low Coverage

AbstractAcross a species range, spatially-varying environments can drive the evolution of local adaptation. Multiples sources of environmental heterogeneity, at small and large scales, draw complex landscapes of selection which may challenge adaptation, particularly when gene flow is high. Because linkage opposes gene flow but also limits the efficiency of natural selection by contrasting pressures, the key to multidimensional adaptation may reside in the heterogeneity of recombination along the genome. Structural variants like chromosomal inversions are important recombination modifiers that form massive co-segregating genomic blocks linking together alleles at numerous genes. In this study, we investigate the influence of chromosomal rearrangements on genetic variation to ask how their contribution to adaptation with gene flow varies across geographic scales. We sampled the seaweed fly Coelopa frigida along a bioclimatic gradient of 10° of latitude, a salinity gradient and across a range of heterogeneous, patchy habitats. We assembled a high-quality genome to analyse 1,446 low-coverage whole-genome sequences, and we found large non-recombining genomic regions, including putative inversions. In contrast to the collinear regions depicting extensive gene flow, inversions and low-recombining regions differentiated populations more strongly, either along an ecogeographic cline or at a fine-grained scale. Those genomic regions were disproportionately involved in associations with environmental factors and adaptive phenotypes, albeit with contrasting patterns between the different recombination modifiers. Altogether, our results highlight the importance of recombination in shaping the selection-migration balance and show that a set of several inversions behave as modular cassettes facilitating adaptation to environmental heterogeneity at local and large scales.

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