Modeling the redox potential during the infiltration in a recharge pond located in the Llobregat river basin

2020 ◽  
Author(s):  
Paula Rodriguez-Escales ◽  
Carme Barba ◽  
Xavier Sanchez-Vila ◽  
Albert Folch
Keyword(s):  
Redox Potential ◽  
Heat Transport ◽  
The Other ◽  
Geochemical Processes ◽  
Aquifer Recharge ◽  
Non Invasive ◽  
Other Hand ◽  
Multiple Processes ◽  
A Cell ◽  
Llobregat River

<div> <p>Redox potential measurements are a sink of multiple processes and factors related to the hydrochemistry of a water.  Normally, by themselves, they do not provide enough information to describe all the processes occurring in a system and they are considered only as “an indicator” that combined with a more detailed hydrochemistry can provide information of the driving processes. There are different reasons why these measurement are not quantitatively valid. First of all, sampling plays an important role. The most common method to determine Eh in groundwater is by using an Eh probe and a cell flow, which implies, by itself, mixing of waters. On the other hand, the Eh reproducibility is also conditioned by the amount of processes considered in a numerical model. Eh depends on several geochemical processes, which at the same time, they are depending on flow and heat transport. The last achievements in sensoring science has allowed to develop sensor probes that allows the Eh measurements in a non-invasive and a continuous way.</p> </div><p>Considering this, in this work we have monitored intensively an infiltration pond (in the context of Managed Aquifer Recharge) in order to develop a proper model to reproduce the Eh. The monitoring was based in the use of non-invasive Eh probes, which registered the Eh every 15 min during a year. During that year, four hydrochemical campaigns were also developed in order to quantify the hydrochemistry of the site. On the other hand, the model considered the flow of the system, the heat transport and a set of geochemical processes which were also depending on temperature. The main processes were the generation of organic matter in the own system, the oxidation of organic carbon using different TEAPs, nitrification and different secondary geochemical processes related, specially, to iron and manganese geochemistry.</p>

The effect of pH and complexation on redox reactions between RS• radicals and flavins

1984 ◽  
Vol 62 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Redox Potential ◽  
Linear Function ◽  
Redox Reactions ◽  
Flavin Adenine Dinucleotide ◽  
Protonated Form ◽  
Redox Properties ◽  
The Other ◽  
Effect Of Ph ◽  
Other Hand ◽  
High Redox Potential

Elementary considerations indicate that thiol radicals, RS•, should have a high redox potential [Formula: see text][Formula: see text]However, the equilibrium [4],[Formula: see text]which is established in the presence of excess RS−, would convert RS•to [Formula: see text] which is a reducing species. Experimentally it was demonstrated that thiol radicals made by γ radiolysis of β-mercaptoethanol solutions effected two-electron oxidation of dihydroflavin FlH2 at pH 6.3 and of FlH− at pH 8. On the other hand, [Formula: see text] readily reduced Fl to FlH2 or FlH− as expected. At pH 9, photostationary states were established after a few minutes radiolysis and the ratios [FlH−]ss/[Fl]ss were a function of [Formula: see text] The main reactions occurring were:[Formula: see text]The values of k19 and k22 were both large. The ratio k19/k22 was ∼0.8 for lumiflavin and ∼0.3 for flavin adenine dinucleotide. The cyclic disulphide anions of lipoamide and dithiothreitol [Formula: see text] also effected two-electron reductions of flavins. However, the protonated form of [Formula: see text] oxidized FlH2, and the photostationary ratio [FlH−]ss/[Fl]ss was an approximate linear function of [Formula: see text]. The implications of the observed changes in redox properties of sulphur radicals on complexation with RS− and protonation were briefly considered.Des considérations élémentaires indiquent que les radicaux thiyles, RS•, doivent avoir un potentiel rédox élevé [Formula: see text][Formula: see text]

The diversity of inflectional periphrasis in Persian

2014 ◽  
Vol 51 (2) ◽  
pp. 327-382 ◽  
Author(s):  
OLIVIER BONAMI ◽  
POLLET SAMVELIAN
Keyword(s):  
General Framework ◽  
Point Of View ◽  
The Other ◽  
Inflectional Morphology ◽  
Formal Grammar ◽  
Conjugation System ◽  
Testing Ground ◽  
Other Hand ◽  
Different Types ◽  
A Cell

Modern Persian conjugation makes use of five periphrastic constructions with typologically divergent properties. This makes the Persian conjugation system an ideal testing ground for theories of inflectional periphrasis, since different types of periphrasis can be compared within the frame of a single grammatical system. We present contrasting analyses of the five constructions within the general framework of a lexicalist constraint-based grammatical architecture (Pollard & Sag 1994) embedding an inferential and realizational view of inflectional morphology (Stump 2001). We argue that the perfect periphrase can only be accounted for by assuming that the periphrase literally fills a cell in the inflectional paradigm, and provide a formal account drawing on using valence for exponence. On the other hand, other periphrastic constructions are best handled by using standard tools of either morphology or syntax. The overall conclusion is that not all constructions that qualify as periphrastic inflection from the point of view of typology should receive the same type of analysis in an explicit formal grammar.

scholarly journals The magnetic survey of the early Scythian burial site and settlements in the Turan-Uyuk valley in Tuva

2020 ◽  
Vol 55 ◽  
pp. 343-368
Author(s):  
Łukasz Oleszczak ◽  
Marcin M. Przybyła ◽  
Igor Pieńkos ◽  
Konstantin V. Chugunov ◽  
Nina A. Zhogova
Keyword(s):  
Russian Federation ◽  
Spatial Arrangement ◽  
The Other ◽  
Magnetic Survey ◽  
Archaeological Excavation ◽  
Burial Site ◽  
Significant Information ◽  
Non Invasive ◽  
Other Hand ◽  
Rule Out

In 2019, Polish archaeologists took part in an expedition of the Hermitage Museum, led by K.V. Chugunov, in Chinge-Tey cemetery, Tuva (Russian Federation). This paper presents the results of magnetic surveys carried out within the so-called western chain of barrows and around the princely barrow of Chinge-Tey I. This method of non-invasive research is very well suited to the landscape and has produced a significant body of information. Among others, the survey of the western chain identified a stone mantle in barrow 8, which makes it different from other barrows from this group, whose mounds were built of earth. Another important result is the identification of a stone circle surrounding a cult feature (certainly associated with eschatological rituals) known as the northern complex. The presence of the circle came as a surprise for the investigators of the site, as it does not manifest itself at all on the surface of the site. On the other hand, worth noting is one negative result, which nevertheless allows for some conclusions, namely the lack of detectable anomalies connected with one of the tombs in the vicinity of Chinge-Tey I (barrow 15). Despite being clearly discernible in the landscape, and even more evident in LIDAR images, the barrow is invisible on images produced with a magnetometer. This means that one cannot rule out a possibility that other structures undetectable by magnetic surveys may be present within the investigated part of the cemetery. Nevertheless, one cannot but arrive at the conclusion that the results generated by the magnetic research provide significant information concerning the spatial arrangement of the cemetery and are helpful in planning of archaeological excavation.

Ausfall der Potenz zur Borstenbildung als „Erbmerkmal“ einer Zellkultur von Drosophila melanogaster

1965 ◽  
Vol 20 (4) ◽  
pp. 290-292 ◽  
Author(s):  
Ernst Hadorn
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Line ◽  
The Other ◽  
Ground Pattern ◽  
Other Hand ◽  
A Cell ◽  
Developmental Factor ◽  
One Year ◽  
Cuticular Structures

The occurrence and the manifestation of a cell line is described which had suddenly and irreversibly lost the potency for forming bristles on any part of the adult cuticle after culturing in vivo over a period of more than one year. On the other hand, it is shown that the cells maintained the capacity for the differentiation of the region-specific ground pattern which consists of hairs and other cuticular structures and which characterize antennae, head parts, legs, wings and the thorax. The aristae are not affected by the change which initiated the bristle-less cell line. Thus it is concluded that the aristae are formations belonging to the ground pattern. A general developmental factor which is indispensible for and common to all bristles regard-less of their organspecific structure is postulated.

scholarly journals Arsenic contamination in surface and groundwater in major parts of Manikganj district, Bangladesh

2016 ◽  
Vol 13 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Atia Akter ◽  
MY Mia ◽  
HM Zakir
Keyword(s):  
Water Samples ◽  
Arsenic Contamination ◽  
The Other ◽  
Geochemical Processes ◽  
Other Hand ◽  
Groundwater Samples ◽  
Standard Value ◽  
Positive Correlations ◽  
Surface And Groundwater

The contamination of groundwater by arsenic (As) in Bangladesh is the largest poisoning of population in history, with millions of people exposed. Thirty (30) water samples were collected from 5 different Upazilas of Manikganj district in Bangladesh to determine the concentration of As as well as to assess the level of contamination. Concentrations of As in waters were within the range of 0.27 to 1.96; 0.43 to 5.09; trace to 6.69 mg L-1 at Singair, Harirampur and Ghior Upazila, respectively. But the concentration of As in waters both of Manikganj sadar and Shivalaya Upazila were trace. All surface and groundwater samples of Singair and Harirampur, and 4 groundwater samples of Ghior Upazila’s exceeded Bangladesh standard value for As concentration (0.05 mgL-1). The highest As concentration (6.69 mgL-1) was found in groundwater of Baliakhora village of Ghior upazila in Manikganj district. The cation chemistry indicated that among 30 water samples, 15 showed dominance sequence as Mg2+ > Ca2+ > Na+ > K+ and 14 samples as Ca2+ > Mg2+ > Na+ > K+. On the other hand, the dominant anion in water samples was Cl- followed by HCO3- and SO42-. Highly significant positive correlations were found in between the concentrations of As and SO42-(r=712**),and As and Ca2+ (r=581*), suggesting similar sources and/or similar geochemical processes controlling the occurrence of these ions in waters.J. Bangladesh Agril. Univ. 13(1): 47-54, June 2015

scholarly journals A Notion of Inversion Number Associated to Certain Quiver Flag Varieties

10.37236/7840 ◽  
2018 ◽  
Vol 25 (3) ◽  
Author(s):  
Lucas Fresse
Keyword(s):  
Algebraic Variety ◽  
Projective Variety ◽  
Smooth Projective Variety ◽  
Cell Decomposition ◽  
The Other ◽  
Flag Varieties ◽  
Other Hand ◽  
Inversion Number ◽  
A Cell ◽  
Nilpotent Endomorphism

We define an algebraic variety $X(d,A)$ consisting of matrices whose rows and columns are partial flags. This is a smooth, projective variety, and we describe it as an iterated bundle of Grassmannian varieties. Moreover, we show that $X(d,A)$ has a cell decomposition, in which the cells are parametrized by certain matrices of sets and their dimensions are given by a notion of inversion number. On the other hand, we consider the Spaltenstein variety of partial flags which are stabilized by a given nilpotent endomorphism. We partition this variety into locally closed subvarieties which are affine bundles over certain varieties called $Y_T$, parametrized by semistandard tableaux $T$. We show that the varieties $Y_T$ are in fact isomorphic to varieties of the form $X(d,A)$. We deduce that each variety $Y_T$ has a cell decomposition, in which the cells are parametrized by certain row-increasing tableaux obtained by permuting the entries in the columns of $T$ and their dimensions are given by the inversion number recently defined by P. Drube for such row-increasing tableaux.

scholarly journals Apparent mitogenetic inactivity of active cells

1933 ◽  
Vol 114 (786) ◽  
pp. 1-9 ◽  
Keyword(s):  
Sufficient Accuracy ◽  
The Other ◽  
Mechanical Activity ◽  
High State ◽  
Powerful Source ◽  
Embryonic Tissues ◽  
Yeast Cultures ◽  
Other Hand ◽  
A Cell ◽  
Positive Results

The emission of mitogenetic rays has been reported from a great variety of cells and tissues but the most powerful source appears to be material which is in a high state of mitotic, metabolic, nervous or mechanical activity (Gurwitsch, 1932). A cursor survey of the literature shows that there is no general agreement concerning the reality of the phenomenon. In most cases, neither the source of the rays nor the means adopted for their detection has been defined with sufficient accuracy to permit consistent results to lie obtained by independent workers. To some extent this difficulty has been met by using photo-electric cells as a means of detecting the rays. Using a potassium cell, Schrieber and Friedlich (1930) failed to detect any radiation know yeast cultures. Seyfert (1932) using a cell of the counter type failed to find any emission of rays from onion roots, yeast cultures, and embryonic tissues. Frank and Rodionov (1932) on the other hand, obtained positive results from active preparations of the frog's sartorius and heart.

scholarly journals Invasive versus Non Invasive Methods Applied to Mummy Research: Will This Controversy Ever Be Solved?

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Despina Moissidou ◽  
Jasmine Day ◽  
Dong Hoon Shin ◽  
Raffaella Bianucci
Keyword(s):  
Soft Tissue ◽  
Minimally Invasive ◽  
Direct Contact ◽  
The Other ◽  
Museum Specimens ◽  
Non Invasive ◽  
Ancient Egyptian ◽  
Other Hand ◽  
Open Questions ◽  
Invasive Techniques

Advances in the application of non invasive techniques to mummified remains have shed new light on past diseases. The virtual inspection of a corpse, which has almost completely replaced classical autopsy, has proven to be important especially when dealing with valuable museum specimens. In spite of some very rewarding results, there are still many open questions. Non invasive techniques provide information on hard and soft tissue pathologies and allow information to be gleaned concerning mummification practices (e.g., ancient Egyptian artificial mummification). Nevertheless, there are other fields of mummy studies in which the results provided by non invasive techniques are not always self-explanatory. Reliance exclusively upon virtual diagnoses can sometimes lead to inconclusive and misleading interpretations. On the other hand, several types of investigation (e.g., histology, paleomicrobiology, and biochemistry), although minimally invasive, require direct contact with the bodies and, for this reason, are often avoided, particularly by museum curators. Here we present an overview of the non invasive and invasive techniques currently used in mummy studies and propose an approach that might solve these conflicts.

Piezoelectric property investigation for sol-gel derived Bi4Ti3O12 thick films

2002 ◽  
Vol 748 ◽  
Author(s):  
Hirofumi Matsuda ◽  
Sachiko Ito ◽  
Takashi Iijima
Keyword(s):  
Thin Film ◽  
Thick Film ◽  
Ferroelectric Property ◽  
The Other ◽  
Piezoelectric Response ◽  
Cell Diameter ◽  
Chemical Solution ◽  
Pt Electrode ◽  
Other Hand ◽  
A Cell

ABSTRACTStrongly (117)-oriented Bi4Ti3O12 (BIT) thin (300 nm in thickness) and thick (900 nm in thickness) films were successfully synthesized from chemical solution and the piezoelectric and ferrelectric properties were studied. The chemical solution of Bi-acetate and Ti-iso-propoxide dissolved in 2-methoxyethanol was spin-coated on Pt(111)/Ti/SiO2/Si(001) substrate, pyrolysed at 450–600 °C and annealed at 600 °C. On 300-nm-thick BIT thin film, Pt top electrodes were deposited through a metal mask by RF-sputtering. For longitudinal piezoelectric displacement measurement in partially unconstraint, 900-nm-thick BIT thick film, an array of disk-shape BIT capacitor cells with Pt top electrode layers standing on the Pt bottom electrode were fabricated by photolithography with the diameter of 80, 50, 30, 20 μm. To recover from plasma damage, post deposition annealing of 300-nm-thick BIT film and post lithograph annealing of 900-nm-thick BIT film were performed, respectively. Longitudinal piezoelectric displacement was measured directly from the Z-feedback and Z-error signals of an AFM piezoscanner head with application of ac electric field at 5 Hz and 1 kHz, respectively between the conductive cantilever tip contacted to the top Pt electrode and the bottom Pt electrode. By the removal of sidewalls of BIT, positive piezoelectric displacement response was measured. The maximum strain was about 0.1 % under bipolar drive (amplitude of 400 kV/cm or 4Ec). From the unipolar driven piezoelectric displacement, piezoelectric coefficient AFM-d33 was measured. The value of AFM-d33 increased to decreasing cell diameter and approached to a somewhat constant value of 12–13 pC/N. Considering the crystalline orientation, this value well corresponds to that of 20 pC/N which were reported previously in single crystal. The result of ferroelectric property measurement was rather contradictory. The values of remanent and saturated polarization Pr=20 and Psat=28 μC/cm2, respectively measured in 300-nm-thick BIT thin film were in good agreement with reported spontaneous polarization Ps=50 μC/cm2 along a-axis with the consideration of measured inclination angle of Ψ=58° between (200) and (117). In 900-nm-thick BIT thick film, on the other hand, measured values of Pr=6–7 μC/cm2 were much poorer than those of the thin film even with the consideration that measurement frequencies were 1 kHz in the thick film and 50 Hz in the thin film, although the films showed (117)-orientation. Measured piezoelectric response may reflect a specific single grain with favorable orientation in a cell, on the other hand, average value of ferroelectric property throughout a cell in the 900-nm-thick BIT thick film having mixed orientation of (117) and (020).

Significant effect of charge microenvironment on the redox potential of [Fe4Se4(SPh)4]2− in solution and inside film

2014 ◽  
Vol 92 (7) ◽  
pp. 625-628
Author(s):  
Diganta Kumar Das ◽  
Dhanada Sarmah ◽  
Raben Ch. Roy
Keyword(s):  
Redox Potential ◽  
Electrode Surface ◽  
The Other ◽  
Positive Shift ◽  
Other Hand ◽  
Surfactant Film

Through this work, we have shown that both the nature and the compactness of charge of the microenvironment around the [Fe4Se4(SPh)4]2−/3− couple are important in determining its redox potential. The redox potential of the [Fe4Se4(SPh)4]2−/3− couple has been measured in pure dimethylformamide (DMF), DMF added with surfactants of different charges, and also in positive surfactant film on an electrode surface. The redox potential becomes 0.090 V positive when the solution microenvironment is made positive compared to that in DMF. On the other hand, if the microenvironment is made positive and static (in the form of a positive film), the positive shift in the potential is 0.265 V, and compactness of charge induced an extra 0.175 V positive shift in the potential.

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