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The Geomorphological Origin of Recession Curves
No full textThis study is motivated by the fact that natural basins share some striking similarities in their basic organization as well as in the way they respond to rainfall input. The central objective here is thus to link the patterns observed in morphology of basins with the patterns that we observe in their hydrologic responses. This study particularly attempts to uncover hidden links between basin morphology and recession curves through a simple conceptual model describing dynamics of saturated channel network or active drainage network (ADN).
Analysis of recession curves is performed by following the framework proposed in the paper by Brutsaert and Neiber, i. e. to interpret –dQ/dt as having a power law relationship with Q (-dQ/dt = kQα), where Q is the discharge at the outlet of a basin at time t. It is shown here that N(l), number of links in a channel network at distance l from their channel heads exhibits a power law relationship with G (l), length of the ADN or length of the channel network at a distance greater than or equal to l from channel heads. And by assuming that the rate of discharge produced by the AND per unit length, q, and the rate at which channel network desaturates towards downstream, c, are constant in space and time, it is argued here that the power law relationship between –d/dt and Q essentially originates from the power law relationship bewteen N(l) and G(l).
It is observed that there is no unique relationship between –dQ/dt and Q for a basin, which implies, the popular assumption that there exists a unique relationship between storage and discharge of a basin is wrong. Also a typical –dQ/dt vs Q curve possess different regimes, because of its association with flood response that we observe shortly after rainfall and observational errors that particularly dominate during very low flow periods. One can observe a fairly good power law relationship between –dQ/dt vs Q, shortly after a rainfall event, continuing for several days. This regime for each individual hydrograph is identified by means of visual interpretation. The power law exponent α for each individual hydrograph of a basin is then computed and the median value is considered as the representing α for the basin . A good agreement is observed between the observed power law exponents, α0, with the geomorphic power law exponents, αg, for 67 United States basins of different sizes and situated in different climatic zones. The correlation is strong, particularly, for the steep basins without having significant human influences, like the presence of dams, cities, extensive agriculture practice etc. Also it is found that the power law exponent α is closely related to the well known Hack’s exponent .
The coefficient k is observed to have power law relationship with any characteristics discharge chosen deonated as Qn, which objectively means the discharge observed after n days of a hydrograph peak. Therefore, one can make different recession curves of a basin collapse on one another by using a suitable multiplicative function. Also it is observed that the power law exponent, γ, as well as the coefficient of determination increases as n increases. Thus the collapse gets more prominent with increase in n.
N(l)/A vs G(l)/A graphs of different basins are found to be collapsing on another, implying that natural basins follow some universal geomorphological themes. Recession curves on the other hand are dependent on many factors like geology, land use, topographic characteristics. It is observed that the recession curves of the basins that have similar geological and topographical characteristics collapse on one another. This observation essentially implies that one can classify natural basins by just observing their recession curves.
This finding further strengthens the assumptions of constant q and constant c made earlier. And finally, it is stressed that the argument, recession curves bearing signatures of basin morphology, can be safely stretched to conclude that the incision of the channel network may be due, to a significant degree, to subsurface flow, in such a way as produce an approximately uniform drainage of the local groundwater system and thus a uniform distribution of q.Questo studio è motivato dal fatto che i bacini naturali sono accomunati da importanti similarità relativamente alla loro organizzazione ed al modo in cui essi rispondono agli impulsi di pioggia. L’obiettivo centrale di questa tesi è quindi quello di individuare una relazione tra alcune caratteristiche osservabili nella morfologia dei bacini e la loro risposta idrologica. In particolare con questo studio si cerca di scoprire analogie nascoste tra la morfologia dei bacini e le curve di recessione attraverso un semplice modello concettuale in grado di descrivere le dinamiche delle reti in saturazione o “Active Drainage Networks” (ADN).
L’analisi delle curve di recessione è effettuata seguendo un approccio proposto in Brutsaert and Neiber (1977), in cui -dQ/dt è rappresentato in funzione di Q attraverso una legge di potenza (-dQ/dt = k Qα), dove Q è il deflusso alla sezione di chiusura di un bacino al tempo t. Nella tesi si mostra che il numero di connessioni (links) in una rete, N(l), ad una distanza l dalle origini (channel heads) è correlato attraverso una legge di potenza con la lunghezza della ADN, cioè la lunghezza delle connessioni ad una distanza maggiore o uguale ad l dalle origini. Assumendo che il deflusso, q , prodotto dalla ADN per unità di lunghezza e la velocità di desaturazione della rete, c, siano costanti nel tempo e nello spazio si discute l’ipotesi che la legge di potenza che lega -dQ/dt e Q abbia origine dalla legge di potenza che lega N(l) e G(l).
Si osserva che non c’è un'unica relazione tra -dQ/dt e Q per un bacino, il che suggerisce che la nota assunzione di una singola relazione tra deflusso e volume di immagazzinamento sia inappropriata. Inoltre, una tipica curva -dQ/dt vs. Q possiede regimi differenti dovuti al suo legame con la risposta superficiale che si osserva subito dopo un evento di pioggia e agli errori di misura effettuati in particolare in periodi di deflusso moderato. Si può osservare una relazione di potenza discretamente buona tra -dQ/dt e Q subito dopo un evento di pioggia e persistente per diversi giorni. L’esponente α della legge di potenza per ciascun idrogramma di un bacino è quindi calcolato e il valore mediano è considerato rappresentativo di tutti i valori di α per il bacino. I valori osservati dell’esponente αo sono in buon accordo con gli esponenti della relazione geomorfologica, αg, per 67 bacini statunitensi di dimensioni diverse e situati in diverse zone climatiche. In particolare si osserva una forte correlazione per bacini con elevata pendenza che non presentano aspetti antropici significativi, come ad esempio dighe, città, diffuse aree coltivate, ecc. Si è inoltre osservato che l’esponente α è significativamente correlato con il noto esponente di Hack.
Si è visto che il coefficiente k è legato attraverso una legge di potenza con qualsiasi deflusso caratteristico selezionato: k=k’Qn-γ, dove Qn è il deflusso osservato dopo n giorni dal picco dell’idrogramma. Di conseguenza, diverse curve di recessione possono essere fatte collassare in un’unica curva. Si osserva inoltre che l’esponente γ della legge di potenza e il coefficiente di determinazione aumentano all’aumentare di n.
Si osserva come le curve N(l)/A vs. G(l)/A di diversi bacini collassino in un'unica curva, il che implica che i bacini naturali seguono una qualche legge geomorfologica universale. Le curve di recessione, invece, dipendono da molti fattori come la geologia, l’uso del suolo, le caratteristiche topografiche. Si osserva che le curve di recessione di bacini con simili caratteristiche topografiche e geologiche collassano in un’unica curva. Questa osservazione implica che è possibile classificare bacini naturali solo sulla base delle curve di recessione. Questa scoperta rafforza ulteriormente l’assunzione di q e c costanti fatta in precedenza. Infine viene messo in evidenza che il fatto che le curve di recessione rappresentano una sorta di “firma” della morfologia dei bacini suggerisce che il deflusso subsuperficiale influenza la rete, in modo da produrre un drenaggio approssimativamente uniforme, e perciò una distribuzione uniforme di q
sj-docx-1-pie-10.1177_09544089211039977 - Supplemental material for Application of soft computing methods in robotic grasping: A state-of-the-art survey
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089211039977 for Application of soft computing methods in robotic grasping: A state-of-the-art survey by Golak B Mahanta, Deepak B B V L and Bibhuti B Biswal in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Distribution of partial credit given to different authors for an imaginary publication with 1–10 authors with one first author and one corresponding author<sup>#</sup>.
No full text<p>: The first and corresponding author is the same.</p><p>#: The last author has been assumed to be the corresponding author.</p
Supplementary_File – Supplemental material for Resting-State Functional Connectivity of the Thalamus in Complete Spinal Cord Injury
No full textSupplemental material, Supplementary_File for Resting-State Functional Connectivity of the Thalamus in Complete Spinal Cord Injury by Keerthana Deepti Karunakaran, Rui Yuan, Jie He, Jian Zhao, Jian-Ling Cui, Yu-Feng Zang, Zhong Zhang, Tara L. Alvarez and Bharat B. Biswal in Neurorehabilitation and Neural Repair</p
The partial credit (a<sub>0</sub>) given to the primary author for articles with 1–100 imaginary authors.
No full text<p>The partial credit (a<sub>0</sub>) given to the primary author for articles with 1–100 imaginary authors.</p
Correlation of <i>Ab-</i>, h- and w-indices with the percentage of credit earned as primary author.
No full text<p>The correlation of <i>Ab-</i>, h- and w-indices to the percentage of credit earned as the primary author of ten individuals randomly chosen from top-20 highly cited authors in the field of Molecular Biology & Genetics of the year 2010 (data source: Thomson Reuters Essential Science IndicatorsSM).</p
Preference programming and inconsistent interval matrices
No full textThe problem of derivation of the weights of altematives from pairwise comparison matrices is long standing. In this paper,Lexicographic Goal Programming (LGP) has been used to find out weights from pairwise inconsistent interval judgment matrices. A number of properties and advantages of LGP as a weight determination technique have been explored. An algorithm for identification and modification of inconsistent bounds is also provided. The proposed technique has been illustrated by means of numerical examples.Analytic hierarchy process; Interval judgment; Preferente programming
Environmental toxicity, redox signaling and lung inflammation:the role of glutathione
No full textGlutathione (gamma-glutamyl-cysteinyl-glycine, GSH) is the most abundant intracellular antioxidant thiol and is central to redox defense during oxidative stress. GSH metabolism is tightly regulated and has been implicated in redox signaling and also in protection against environmental oxidant-mediated injury. Changes in the ratio of the reduced and disulfide form (GSH/GSSG) can affect signaling pathways that participate in a broad array of physiological responses from cell proliferation, autophagy and apoptosis to gene expression that involve H(2)O(2) as a second messenger. Oxidative stress due to oxidant/antioxidant imbalance and also due to environmental oxidants is an important component during inflammation and respiratory diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, and asthma. It is known to activate multiple stress kinase pathways and redox-sensitive transcription factors such as Nrf2, NF-kappaB and AP-1, which differentially regulate the genes for pro-inflammatory cytokines as well as the protective antioxidant genes. Understanding the regulatory mechanisms for the induction of antioxidants, such as GSH, versus pro-inflammatory mediators at sites of oxidant-directed injuries may allow for the development of novel therapies which will allow pharmacological manipulation of GSH synthesis during inflammation and oxidative injury. This article features the current knowledge about the role of GSH in redox signaling, GSH biosynthesis and particularly the regulation of transcription factor Nrf2 by GSH and downstream signaling during oxidative stress and inflammation in various pulmonary diseases. We also discussed the current therapeutic clinical trials using GSH and other thiol compounds, such as N-acetyl-l-cysteine, fudosteine, carbocysteine, erdosteine in environment-induced airways disease
On reliable time-frequency characterization and delay estimation of stimulus frequency otoacoustic emissions
No full text- …
