scholarly journals DINÂMICA DA ZONA DE RASA DE SHOALING E O TRANSPORTE DE SEDIMENTOS NA DESEMBOCADURA SUL DO COMPLEXO ESTUARINO DE PARANAGUÁ – PR

Author(s):  
Georgina Jacintho Martins ◽  
Eduardo Marone ◽  
Rodolfo José Angulo ◽  
Mauricio Almeida Noernberg ◽  
Clécio José Lopes De Quadros

O presente trabalho caracteriza os parâmetros de ondas e analisa o potencial hidrodinâmico para o transporte de sedimentos por tração e de material particulado em suspensão, na costa adjacente à desembocadura sul do complexo estuarino de Paranaguá em decorrência do regime de ondas e das correntes de marés atuantes em períodos de mar calmo. A área estudada apresenta uma dinâmica complexa, devido à sua localização na saída de um grande estuário em uma costa com energia de onda relativamente elevada. Os objetivos principais foram os de caracterizar os parâmetros de ondas, avaliar o padrão de correntes junto à costa e estimar o potencial das correntes para o transporte de sedimentos. A caracterização dos parâmetros de ondas e das correntes paralelas à costa foi obtida através de correntômetro/ondômetro direcional eletromagnético InterOcean S4, fundeado imediatamente atrás da arrebentação das ondas na praia do Balneário Atami. Os fundeios foram realizados em períodos de baixa energia de ondas, quando era possível a sua instalação, sendo que os resultados são referentes a tais condições. Os resultados apontaram que a direção preferencial de chegada de ondas é de SE, sendo que a direção predominante de transporte médio longitudinal à costa foi de nordeste para sudoeste. As inversões das correntes associadas às variações da maré indicaram uma efetiva influência destas na direção do transporte. Com base nos resultados obtidos, são apresentadas sugestões visando incentivar a implementação de estratégias de monitoramento do fluxo de sedimentos costeiro. SHALLOW SHOALING ZONE DYNAMICS AND SEDIMENT TRANSPORT IN THE PARANAGUÁ BAY OUTLET Abstract This work presents a characterization of wave parameters and climate. It analyzes the hydrodynamic potential for sediments transport by traction as well by suspension (suspended particulate matter - SPM), carried out both by coastal currents, waves and the tidal circulation acting in the adjacent coast of the southern outlet of Paranaguá Estuarine Complex. This area presents a complex dynamics, due to its location, morphology and the interaction of several coastal processes acting among its limits. The main goal was to characterize the wave parameters and climate, to identify the coastal currents, and to understand the roles of these currents for the sediments transport, quantifying its magnitude. The characterization of the wave parameters and of the coastal currents was obtained through mooring a directional wave and current gauge InterOcean S4 immediately seaward of the surf of Atami beach, PR. The moorings were accomplished in periods of low wave energy, the only ones allowing the deployment, and the results are regarding such conditions. The results suggested that the preferential direction of wave propagation is SE and the predominant direction of the mean transport, longitudinal to the coast, was from Northeast to Southwest. The inversion of the longitudinal currents was associated to the tidal changes and they indicated an effective influence of the tidal currents, acting in the southern outlet of the Paranaguá estuary, in the direction of the mean mass transport. The hydrodynamic complexity of the place was directly related to these constraints, being linked to the net balance of the forcing of the tidal currents and the waves incidence. According to the obtained results, some suggestions were presented with the objective of suggesting strategies for the waves, currents and coastal transport studies, as a powerful tool for managing coastal zone problems.

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1004
Author(s):  
John Lobulu ◽  
Hussein Shimelis ◽  
Mark D. Laing ◽  
Arnold Angelo Mushongi ◽  
Admire Isaac Tichafa Shayanowako

Striga species cause significant yield loss in maize varying from 20 to 100%. The aim of the present study was to screen and identify maize genotypes with partial resistance to S. hermonthica (Sh) and S. asiatica (Sa) and compatible with Fusarium oxysporum f. sp. strigae (FOS), a biocontrol agent. Fifty-six maize genotypes were evaluated for resistance to Sh and Sa, and FOS compatibility. Results showed that FOS treatment significantly (p < 0.001) enhanced Striga management compared to the untreated control under both Sh and Sa infestations. The mean grain yield was reduced by 19.13% in FOS-untreated genotypes compared with a loss of 13.94% in the same genotypes treated with FOS under Sh infestation. Likewise, under Sa infestation, FOS-treated genotypes had a mean grain yield reduction of 18% while untreated genotypes had a mean loss of 21.4% compared to the control treatment. Overall, based on Striga emergence count, Striga host damage rating, grain yield and FOS compatibility, under Sh and Sa infestations, 23 maize genotypes carrying farmer preferred traits were identified. The genotypes are useful genetic materials in the development of Striga-resistant cultivars in Tanzania and related agro-ecologies.


Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 945-956 ◽  
Author(s):  
Hong-Wen Deng

Abstract Deng and Lynch recently proposed estimating the rate and effects of deleterious genomic mutations from changes in the mean and genetic variance of fitness upon selfing/outcrossing in outcrossing/highly selfing populations. The utility of our original estimation approach is limited in outcrossing populations, since selfing may not always be feasible. Here we extend the approach to any form of inbreeding in outcrossing populations. By simulations, the statistical properties of the estimation under a common form of inbreeding (sib mating) are investigated under a range of biologically plausible situations. The efficiencies of different degrees of inbreeding and two different experimental designs of estimation are also investigated. We found that estimation using the total genetic variation in the inbred generation is generally more efficient than employing the genetic variation among the mean of inbred families, and that higher degree of inbreeding employed in experiments yields higher power for estimation. The simulation results of the magnitude and direction of estimation bias under variable or epistatic mutation effects may provide a basis for accurate inferences of deleterious mutations. Simulations accounting for environmental variance of fitness suggest that, under full-sib mating, our extension can achieve reasonably well an estimation with sample sizes of only ∼2000-3000.


Lubricants ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 29
Author(s):  
Carl F. O. Dahlberg ◽  
Jonas Faleskog ◽  
Per-Lennart Larsson

Correlation of sharp indentation problems is examined theoretically and numerically. The analysis focuses on elastic-plastic pressure-sensitive materials and especially the case when the local plastic zone is so large that elastic effects on the mean contact pressure will be small or negligible as is the case for engineering metals and alloys. The results from the theoretical analysis indicate that the effect from pressure-sensitivity and plastic strain-hardening are separable at correlation of hardness values. This is confirmed using finite element methods and closed-form formulas are presented representing a pressure-sensitive counterpart to the Tabor formula at von Mises plasticity. The situation for the relative contact area is more complicated as also discussed.


2012 ◽  
Vol 510-511 ◽  
pp. 271-276 ◽  
Author(s):  
Tayyaba Asim ◽  
R. Ahmed ◽  
M.S. Ansari

Nickel deposited on carbon has been used as adsorbent to recover Zn (II) from aqueous system. The adsorbent was synthesized by depositing nickel nitrate on carbon under inert conditions and decomposing it to nickel by raising the temperature, washing and vacuum drying. Various techniques including XRD, FTIR, and SEM were employed for its characterization. FTIR showed that the nickel deposition enhanced the carbon functionalization due to presence of OH, C=O and C-O groups.Average crystallite size ofabout 9 nm was determined from XRD. Nickel deposition resulted in further division particles as indicated from the morphological study. Zn (II) was subjected to adsorptionon the synthesized adsorbent. It was observed that the rate of adsorption increased significantly on the nickel deposited carbon than the carbon alone. Morris-Weber, Lagergren and Reichenberg models were applied to find out the type and rate of adsorption employingfirst and second order rate equations.The adsorption data were applied toLangmuir, Freundlich and D-R isotherms and values of isotherm constants were calculated and were higher for Ni/C than carbon alone. The mean free energy of zinc sorption on carbon and Ni/C are 16.67 and 18.26 kJmol-1 which shows chemisorption. Thermodynamic studies were done to find out the effect of temperature on sorption. Positive values of ΔH and negative values of ΔG show endothermic and spontaneous type of sorption.


1995 ◽  
Vol 05 (05) ◽  
pp. 1351-1355
Author(s):  
VLADIMIR FEDORENKO

We give a characterization of complex and simple interval maps and circle maps (in the sense of positive or zero topological entropy respectively), formulated in terms of the description of the dynamics of the map on its chain recurrent set. We also describe the behavior of complex maps on their periodic points.


2015 ◽  
Vol 28 (23) ◽  
pp. 9332-9349 ◽  
Author(s):  
Liang Wu ◽  
Zhiping Wen ◽  
Renguang Wu

Abstract Part I of this study examined the modulation of the monsoon trough (MT) on tropical depression (TD)-type–mixed Rossby–gravity (MRG) and equatorial Rossby (ER) waves over the western North Pacific based on observations. This part investigates the interaction of these waves with the MT through a diagnostics of energy conversion that separates the effect of the MT on TD–MRG and ER waves. It is found that the barotropic conversion associated with the MT is the most important mechanism for the growth of eddy energy in both TD–MRG and ER waves. The large rotational flows help to maintain the rapid growth and tilted horizontal structure of the lower-tropospheric waves through a positive feedback between the wave growth and horizontal structure. The baroclinic conversion process associated with the MT contributes a smaller part for TD–MRG waves, but is of importance comparable to barotropic conversion for ER waves as it can produce the tilted vertical structure. The growth rates of the waves are much larger during strong MT years than during weak MT years. Numerical experiments are conducted for an idealized MRG or ER wave using a linear shallow-water model. The results confirm that the monsoon background flow can lead to an MRG-to-TD transition and the ER wave amplifies along the axis of the MT and is more active in the strong MT state. Those results are consistent with the findings in Part I. This indicates that the mean flow of the MT provides a favorable background condition for the development of the waves and acts as a key energy source.


2004 ◽  
Vol 467-470 ◽  
pp. 33-38 ◽  
Author(s):  
Rénald Brenner ◽  
O. Castelnau ◽  
Brigitte Bacroix

The description of the mechanical state of a polycrystal is presented in the framework of the mean-field approaches and attention is paid to the fields heterogeneity. For nonlinear behaviours, the importance of the chosen model is emphasized with respect to relevant microstructural parameters for recrystallisation.


2021 ◽  
Author(s):  
Shixiao Dong ◽  
Deyu Huang ◽  
Zheng Wang ◽  
Guanyou Zhang ◽  
Fengjuan Zhang ◽  
...  

Abstract Rotavirus was the an important causative agent of acute gastroenteritis in children. In China, rotavirus was positive in approximately 30% of the diarrhea children and become a serious public problem. This study was carried out to investigate the clinical and molecular epidemic characterization of rotavirus infection among children under 5 years old with acute diarrhea in Shandong province, China. From July 2017 to June 2018, a total of 1211 fecal specimens were detected and the prevalence of rotavirus infection was 32.12%. The mean age of positive children was 12.2 ± 10.9 months and the highest infection rate was observed in children aged 7–12 months with a rate of 41.64%. G9P[8] (76.61%) was the most prevalent combinations followed by G2P[4] (7.20%), G3P[8] (3.60%) and G9P[4] (2.06%). In addition to diarrhea, vomiting, fever and dehydration were the most common accompanied symptoms. In general, there was no significant difference in clinical manifestations among different age groups. However, the clinical manifestations between vaccinated and unvaccinated children were significantly different. Vaccinated children showed lower incidence and frequency of vomiting, lower incidence and degree of dehydration, lower incidence of severe cases than unvaccinated children. The findings suggested necessary to continue rotavirus strains surveillance in order to monitor the change of prevalent genotype. Moreover, introducing vaccine into national immunization program to prevent and control rotavirus infections is needed in China.


2015 ◽  
Vol 71 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
Francisca N. Rein ◽  
Weizhong Chen ◽  
Brian L. Scott ◽  
Reginaldo C. Rocha

We report the structural characterization of [6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine](2,2′-bipyridine)chloridoruthenium(II) hexafluoridophosphate, [RuCl(C10H8N2)(C30H20N6)]PF6, which contains the bidentate ligand 2,2′-bipyridine (bpy) and the tridendate ligand 6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine (tpy–tpy). The [RuCl(bpy)(tpy–tpy)]+monocation has a distorted octahedral geometry at the central RuIIion due to the restricted bite angle [159.32 (16)°] of the tridendate ligand. The Ru-bound tpy and bpy moieties are nearly planar and essentially perpendicular to each other with a dihedral angle of 89.78 (11)° between the least-squares planes. The lengths of the two Ru—N bonds for bpy are 2.028 (4) and 2.075 (4) Å, with the shorter bond being opposite to Ru—Cl. For tpy–tpy, the mean Ru—N distance involving the outer N atomstransto each other is 2.053 (8) Å, whereas the length of the much shorter bond involving the central N atom is 1.936 (4) Å. The Ru—Cl distance is 2.3982 (16) Å. The free uncoordinated moiety of tpy–tpy adopts atrans,transconformation about the interannular C—C bonds, with adjacent pyridyl rings being only approximately coplanar. The crystal packing shows significant π–π stacking interactions based on tpy–tpy. The crystal structure reported here is the first for a tpy–tpy complex of ruthenium.


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