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The Code with – the capability of – Internal Assessment of Uncertainty (CIAU) is a tool proposed by the Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione (DIMNP) of the University of Pisa. Other Institutions including the nuclear regulatory body from Brazil, “Comissäo Nacional de Energia Nuclear”, contributed to the development of the tool. The CIAU aims at providing the currently available Relap5/Mod3.2 system code with the integrated capability of performing not only relevant transient calculations but also the related estimates of uncertainty bands. The Uncertainty Methodology based on Accuracy Extrapolation (UMAE) is used to characterize the uncertainty in the prediction of system code calculations for light water reactors and is ‘internally’ coupled with the above system code. Following an overview of the CIAU development, the present paper deals with the independent qualification of the tool. The qualification test is performed by estimating the uncertainty bands that should envelope the prediction of the LOBI test Al-93 (small break loss of coolant accident). The current limitation of the ‘error’ database, implemented into the CIAU prevented a final demonstration of the qualification. However, all the steps for the qualification process are demonstrated.

L’objectif de cette étude est de présenter l’évolution des données d’incidence et de mortalité du cancer des organes génitaux externes de l’homme dans l’Hérault à partir des données du Registre des tumeurs de l’Hérault (RTH) sur une période de 30 ans.

L’objectif de cette étude est de présenter l’évolution de l’épidémiologie du cancer du rein dans l’Hérault à partir des données collectées par le registre des tumeurs de l’Hérault (RTH) sur une période de 30 ans.

On observe dans l’Hérault une nette augmentation de l’incidence des cancers urologiques. Le registre des tumeurs de l’Hérault (RTH) a recueilli 1961 tumeurs urologiques en 2016, soit 21,4 % de l’ensemble des tumeurs de l’Hérault pour cette année-là. La création d’un registre spécialisé en onco-urologie nous est apparue nécessaire. L’objectif de cet article est de décrire le fonctionnement de RHESOU et de donner quelques exemples de résultats.

Although many advanced nonlinear process control techniques have been developed over the past decade, classic control based on feedback response still has its place. This is mostly so because feedback empirical control is robust and simple to implement and does not require fancy calculations or high-qualified operational manpower to operate it. This work has developed an application written in LabVIEW®environment capable of doing a fully automated single-input single-output control. Preliminary tests were performed in a drilling fluid production unit, controlling flow rate through manipulation of the pump power engine. In the future, tests in the same plant of pressure control by choke valves manipulation will be performed (as found in rig sites, where wellbore pressure is controlled by manipulation of such valves). The final goal is to implement such software in a real rig site, to help operators in drilling control areas such as flow rate and wellbore pressure. The produced software has embedded three self-developed features: automatic plant identification (API), auto-tuning (ABAP) and controllers auto-switch (CAS). The API determines automatically the linearity of the process determining the empirical parameters according to Sundaresan and Krishnaswamy technique. In sequence, it calculates the parameters for P, PI and PID controllers using Cohen–Coon and Ziegler–Nichols methods. The API method automates the sequence of tests necessary to implement the Sundaresan and Krishnaswamy empirical approach. The ABAP feature based on heuristic rules tunes in real time the controllers’ parameters to optimize its response. The CAS allows automatic switch between controllers and parameters to avoid instability, overshoots and creates a synergy with ABAP feature. The results have shown that the API feature is a good optimizer reducing the invested time to calculate all the parameters, from hours to a few minutes. The CAS results demonstrated an associative property with the ABAP feature to mitigate instabilities and overshoots. Therefore, the preliminary results suggested this software is a unique and important tool to improve performance, profitability and reliability during offshore and onshore drilling operations. Moreover, this application could be used in any industry with an approximate first-order dynamic system due to its robustness and a low human interaction need.

En los últimos años se han introducido nuevas modalidades de mantenimiento de analgesia epidural (AE).

This paper analyzes the effectiveness of decentralized strategies for dispatching rolling stock and train drivers in a railway system. Such strategies give operators a robust alternative in case centralized control fails due to an abundance of infrastructure or rolling stock disruptions or information system malfunctions. We test the performance of four rolling stock and two driver dispatching strategies in a microscopic simulation. Our test case is a part of the Dutch railway network, containing eleven stations linked by four train lines. We find that with the decentralized dispatching strategies, target frequencies of the lines are approximately met and train services are highly regular without large delays. Especially strategies that allow rolling stock to switch between lines result in a high performance.

O advento da cirurgia minimamente invasiva, desde a década de 90 levou diversos centros internacionais de cirurgia urológica a desenvolver a retroperitoneoscopia como via de acesso para o tratamento cirúrgico de múltiplas patologias urológicas. Objetivos:O objetivo deste trabalho foi analisar a experiência inicial em Retroperitoneoscopia do Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa.

In this work, electron doping of the anisotropic phase Ca4Mn3O10 was achieved by substitution of manganese by vanadium. No significant structural modifications were detected to the highest substitution ratio of 10% achieved. The introduction of vanadium decreases the electrical resistivity, described as two-dimensional variable range hopping, and induces the appearance of a ferromagnetic behavior. Consistently negative magnetoresistance develops in the magnetic ordered state. These results are characteristic of the presence of double exchange interactions, indicating that vanadium doping induces mixed valence of manganese.

This paper describes the properties of Ni-B/Cu multilayers deposited on low carbon steel substrates by dynamic chemical plating (DCP), a new direct wet plating process that allows the deposition of alternating layers of Ni-B and Cu with an individual layer thickness of 0.2 to 0.3 µm (7.9 to 11.8 µ-in.), at room temperature over the course of a few minutes. Assemblies of five to 20 alternating layers of Ni-B and Cu were obtained and the influence on the total number of layers on the properties of the assemblies was investigated. Analysis by SEM showed that continuous films with a homogeneous thickness distribution were deposited. Results showed that the thickness was dependent only on the deposition parameters and not on the surface properties, after the first deposited layer. The adhesion properties of the Ni-B/Cu multilayers as well as the thickness and the morphology of cross sectional multifilms with and without heat treatment were investigated. Despite the absence of cupronickel alloys even after heat treatment, the results showed that Ni-B/Cu multilayers obtained by DCP improve the corrosion resistance of carbon steel in 5% of sodium chloride. [ABSTRACT FROM AUTHOR]

Today’s and tomorrow’s globalized world requires the acceptance of each other’s capabilities, competence and metrological traceability of measurements to the International System of Units and thus mutual acceptance of quantitative results. Therefore, mutually and publicly recognized standards and certificates are needed at national and international levels. An important step to attain this ambitious goal is to intensify regional metrological collaboration. The exercises of interlaboratorial comparisons are important as part of a system to guaranty the quality of analysis. To estimate the sources of uncertainty associated with the determination of toxic trace element concentrations in rice and to perform an interlaboratorial comparison, a sample containing cadmium, copper, lead and zinc was distributed to four Brazilian laboratories. The laboratories used atomic emission spectroscopy, graphite furnace atomic absorption spectroscopy and flame atomic absorption spectroscopy. The evaluation of the results provided by the laboratories was made by statistical and graphical methods comparing the results of each laboratory to the certified value.

Chromaffin granules are organelles similar to the large dense cored vesicles (LDCV) found in many neurons. They accumulate catecholamines and other soluble components at concentrations that may result in a hypertonic intravesicular medium. However, they maintain isotonicity with cytosol probably as result of aggregation of intravesicular components. Chromogranins could play a role in that isotonic equilibrium as well as in the control of the free diffusion of catecholamines to the external media once granule fusion occurs. Although the release of soluble components upon exocytosis has been considered as a merely passive phenomenon, we have demonstrated that it is finely modulated by second messengers and, therefore, interfered with drugs. Our data suggest that the main regulatory target for these signals is not the fusion pore but most probably intravesicular factors like pH and chromogranins. We also present results suggesting that chromogranins are involved in the mechanisms that modulate the latter steps of exocytosis. Of importance, changes in the kinetics of exocytosis or/and in the quantal size can result in profound modifications to synaptic performance, at least in those processes mediated by LDCV.

We present an analysis of spin injection efficiency that is of general application and relevant to a wide range of spin-electronic devices. By applying simple band structure ideas to a single interface between a metallic ferromagnet and a three-dimensional semiconductor, two conflicting figures of merit are identified - spin accumulation and polarization of injected current - and their validity to the analysis of different device types is discussed. The injected spin accumulation is smaller than the all-metal injection case by a factor (m*/m_e)^3/2(kT/E_F)^1/2e^ϵ_D/kT. Moreover, the injected spin current at the interface is reduced by the factor (m*/m_e)^3/2(kT/E_F)(γ_S/γ_F) e^ϵ_D/kT, where γ for a particular material is the square root of its momentum scattering to spin-flip scattering ratio, m* and m_e are the effective and free masses, respectively, and ϵ_D is the donor binding energy. These results are consequent on the boundary condition that the spin channel electrochemical potentials are continuous at the interface. By inserting an insulating tunnel barrier between the ferromagnet and the semiconductor, not only is this boundary condition removed and the spin polarization of the injected current restored to the all-metal magnitude, but also the spin accumulations in the metal and the semiconductor even have opposite signs. This implies that thin or discontinuous tunnel barriers have the worst spin injection efficiency of any configuration. We finally note that for injected spin current into metals with polarization approaching 100%, the Fermi surface is polarized to a depth which exceeds the equilibrium carrier depth by a factor l_SD/λ, hence >>1.

The influence of several ethoxylated additives (ethyleneglycol and polyethyleneglycol polymers of different molecular weights) on the nucleation, growth mechanism and morphology of zinc electrodeposited from an acidic chloride bath is reported. The electrochemical study was carried out using cyclic voltammetry, inversion potential and chronoamperometric techniques. The dimensionless graphs model was applied to analyse the nucleation process and the results showed that the studied additives have a blocking effect on the electrodeposition of zinc. This effect occurs in the first stages of the nucleation process and is dependent on the molecular weight of the additive. Changes induced by the presence of additives in the morphology and grain size of the deposits were observed using SEM analysis. Results show that the presence of additives modifies the nucleation process and determines the final properties of the deposits.

Cooperativity in the interactions among proteins subunits and DNA is crucial for DNA recognition. LexA repressor was originally thought to bind DNA as a monomer, with cooperativity leading to tighter binding of the second monomer. The main support for this model was a high value of the dissociation constant for the LexA dimer (micromolar range). Here we show that the protein is a dimer at nanomolar concentrations under different conditions. The reversible dissociation of LexA dimer was investigated by the effects of hydrostatic pressure or urea, using fluorescence emission and polarization to monitor the dissociation process. The dissociation constant lies in the picomolar range (lower than 20 pM). LexA monomers associate with an unusual large volume change (340 ml/mol), indicating the burial of a large surface area upon dimerization. Whereas nonspecific DNA has no stabilizing effect, specific DNA induces tightening of the dimer and a 750-fold decrease in the K(d). In contrast to the previous model, a tight dimer rather than a monomer is the functional repressor. Accordingly, the LexA dimer only loses its ability to recognize a specific DNA sequence by RecA-induced autoproteolysis. Our work provides insights into the linkage between protein-protein interactions, DNA recognition, and DNA repair.

Small monomeric proteins are the best models for studying protein folding, but they are often too stable for denaturation using pressure as the sole perturbant. In the present work we subject [CI-2(1-40).(41-64)], a noncovalent complex formed by the association of two complementary fragments of the chymotrypsin inhibitor-2, to high pressure to investigate the folding mechanism of a model protein. Pressures up to 3.5 kilobar do not affect the intact protein, but it can be unfolded reversibly by pressure in the presence of subdenaturing concentrations of guanidine chloride, with free energy and molar volume changes of 2.5 kcal mol-1 and 42.5 ml mol-1, respectively. In contrast, the complex can be reversibly denatured by high pressure without the addition of chemical denaturants. However, the process is clearly independent of the protein concentration, indicating lack of dissociation. We determined a change in the free energy of 1.4 kcal mol-1 and a molar volume change of 35 ml mol-1 for the pressure denaturation of the complex. A persistent quenching of the tryptophan adds further evidence for the presence of residual structure in the high pressure-denatured state. This state also appears to be compact as the small volume change indicates, compared with pressure denaturation of naturally occurring dimers. Based on observations of a number of pressure-denatured states and on characteristics of large CI-2 fragments with a solvent accessible core but maintaining tertiary interactions, the structure of the pressure-denatured state of the CI-2 complex could be explained by an ordered molten globule-like conformation.

Abstract: In the intact rat adrenal gland perfused with an oxygenated Krebs-bicarbonate solution at 37�C, the electrical field stimulation of splanchnic nerves (100 V, 0.5 ms duration, 10 Hz during 10 s) produced transient catecholamine release peaks that were reproduced in subsequent stimuli, applied at 8-min intervals. ω-Conotoxin GVIA (0.3 �M) caused only a modest inhibition of the secretory response, suggesting that the N-subtype of voltage-dependent Ca2+ channels are scarcely involved in such a response. Both ω-conotoxin MVIIC (1 �M) and furnidipine (1 �M) halved the secretion, suggesting that the L- and P/Q-types of Ca2+ channels were involved. N-type Ca2+ channels appear to be involved in the maintenance of secretion in response to sustained stimulus since ω-conotoxin GVIA (0.3 �M) reduced the catecholamine output to 28%. When secretion was elicited by acetylcholine (10 �M), furnidipine reduced the catecholamine release by 50% and ω-conotoxin MVIIC by 40%, whereas ω-conotoxin GVIA did not modify the response. The K+-induced secretory responses (23.6 mM K+, 15 s) were reduced 75% by furnidipine and 45% by ω-conotoxin MVIIC, indicating that this type of stimulation preferentially recruited L-type channels. These data show that electrical stimulation recruits Ca2+ channel subtypes different from those recruited by direct depolarization of chromaffin cells.

1. Muscarinic agonists enhanced catecholamine release from perfused cat adrenal glands with the following relative order of potencies: methacholine greater than oxotremorine greater than McN‐A‐343 greater than pilocarpine greater than bethanechol greater than muscarine. Because a continuous online electrochemical detection system was used to monitor catecholamine release, this sequence could be obtained at concentrations much lower (1‐10 microM) and during much shorter stimulation times (3‐30 s) than in previous reports. 2. All muscarinic agonists used secreted adrenaline preferentially over noradrenaline. Methacholine evoked a sustained, non‐desensitizing response in the cat adrenal, which declined to basal levels of secretion immediately after Ca2+ removal: upon Ca2+ restoration secretion was restored to the previous plateau. 3. In addition to evoking a direct secretory response, low concentrations of methacholine, pilocarpine, bethanechol or muscarine clearly potentiated cat adrenal secretory responses evoked by pulses of nicotine (2 microM for 30 s) or high K+ (17.7 mM for 30 s). 4. [3H]Quinuclydinyl benzylate (QNB) specifically bound to cat adrenomedullary membranes with a saturating monophasic curve, suggesting a single binding site with a KD of 23 pM and a Bmax of 67 fmol (mg protein)‐1. Preferential displacement by atropine over pirenzepine suggests that the binding site is associated to a M2‐type muscarinoceptor. 5. Methacholine (3‐300 microM) did not enhance the spontaneous catecholamine release from perfused bovine intact adrenal glands or superfused chromaffin cells. Neither did the drug affect secretion evoked by dimethylphenylpiperazinium (10 microM for 3 s) or K+ (35 mM for 3 s) from isolated superfused bovine adrenal chromaffin cells. 6. [3H]QNB bound to purified bovine adrenomedullary plasma membranes with a KD of 29 pM and a Bmax of 89 fmol (mg protein)‐1. Displacement by pirenzepine suggests the presence of two binding sites (Hill coefficient = 0.64) with Ki1 of 39 nM and Ki2 of 2734 nM. 7. Because the ionophore A23187 enhanced K(+)‐evoked secretion in both, bovine and cat adrenals, it seems that a similar cytosolic Ca2+ rise induced by muscarinic stimulation might constitute the underlying mechanism both to cause a secretory response per se as well as the potentiation of catecholamine release evoked by nicotinic or high K+ stimulation. However, it is unclear why the bovine behaves differently from the feline chromaffin cell as far as the muscarine‐evoked effects are concerned.(ABSTRACT TRUNCATED AT 400 WORDS)

Use of precision farming technologies requires better understanding of nutrient variability in soils and plants. This study assessed patterns of spatial variability of plant P and K content of no‐till corn (Zea maysL.) and soybean [Glycine max(L.) Merr.] on eight fields that had varied histories of fertilization. One hundred composite whole‐plant samples (five corn plants and 10 soybean plants at V5 to V6 growth stages) were collected in late spring from 2.2‐m2areas spaced 3.05 m along two intersecting transects. Dry weight (DW) and total P and K concentrations were measured in all samples. Plots of observed values, variography, and fast Fourier transform (FFT) analyses revealed clustering of values and periodic patterns of DW and nutrient content in most fields. The patterns of variability varied greatly among fields and directions within a field. The diversity of patterns probably results from nonuniform distribution of fertilizers and animal manures. Patterns of plant K uptake (KU) followed patterns of plant K concentration (KC) in some fields and those of DW in others. Patterns of plant P uptake (PU), however, usually followed those of DW. Implementation of plant analysis for no‐till fields should address situations with high spatially structured variability of cyclic or clustered structure. The results show that the structure of the variability in P and K uptake is site specific and that both the sampling scheme and the optimal separation distance between sampling positions would vary greatly among fields. The results suggest that plant analysis would have similar sampling problems to those of soil testing for representing the P and K supplies of corn and soybean fields.

The rate of catecholamine release from cat adrenal glands perfused with Krebs solution containing 59 mM K declined exponentially during the first few minutes of depolarization. The rate of decline was considerably slower when Ca was substituted by Sr. The late addition of Ca, Sr or the Ca‐channel activator BAY‐K‐8644 evoked a revival of secretion when catecholamine release was inactivated by prior K depolarization; the revival of secretion was independent of the depolarization time. These data demonstrate that inactivation of catecholamine release is specifically dependent on Ca; the modulatory role of Ca on secretion seems to be exerted at a step distal to the transmembraneous Ca channel.

Secretion of catecholamines from individual vesicles of bovine adrenal medullary cells was studied with amperometry in media of various osmolarities and compared with results obtained in isotonic physiological buffer (315 mosM). Hypotonic solutions caused an increase in the number of amperometric spikes evoked by brief exposure to 5 mM Ba2+. Under moderate hypertonic conditions (630 mosM), individual vesicular events were decreased in frequency, and lower amounts were secreted per event. Furthermore, the events were temporally broadened relative to those observed during release in isotonic conditions. At 970 mosM, exposure to 5 mM Ba2+ evoked even smaller secretory events that resemble the prespike feature that has been attributed to the initial opening of the fusion pore. The lack of large spikes is not due to failure of Ba2+ entry because fura-2 fluorescence reveals an increase in intracellular divalent ions. After exposure to Ba2+ in hypertonic solution, spikes could be induced with isotonic solution transiently directed onto the cell, but this process was not accompanied by a change in the concentration of intracellular divalent ions. Thus, this procedure provides an unique opportunity to temporally separate exocytotic secretion from entry of divalent ions.

We investigated the effects and interaction of four irradiances, 37, 53, 70 and 100% full sunlight, and the endomycorrhizae Glomus macrocarpum and Glomus fasciculatum on the development of seedlings of Fraxinus pennsylvanica Marsh. At all irradiances, mycorrhizal seedlings were taller and larger in diameter than nonmycorrhizal seedlings. Seedlings inoculated with G. macrocarpum showed the best height growth at 70% or less of full sunlight, whereas seedlings inoculated with G. fasciculatum grew best at 37 and 53% full sunlight. Leaf area was greatest in shaded seedlings and was enhanced by mycorrhizal inoculation. Shoot/root ratios were greater for mycorrhizal than for nonmycorrhizal seedlings. At intermediate light intensities, percent root length colonized was greatest, whereas the concentrations of soluble sugar and starch in roots were at intermediate levels.

The effects of 17-alpha-estradiol on the secretion of catecholamines from the perfused bovine and cat adrenal gland and bovine chromaffin cells in culture elicited by dimethylphenylpiperazinium (DMPP), methacholine and high potassium were studied. In perfused cat adrenal glands, secretion of catecholamines evoked by pulses of DMPP (1 microM for 30 sec) was decreased by 17-alpha-estradiol at concentrations of 1 and 10 microM by 50 and 80%, respectively. However, secretion evoked by pulses of methacholine (3 microM for 30 sec) was not affected by 1 microM of 17-alpha-estradiol and was affected to a variable extent by 10 microM 17-alpha-estradiol. Catecholamine secretion evoked by higher concentrations of methacholine (100 microM for 60 sec) was reduced by 50% by 10 microM 17-alpha-estradiol. 17-alpha-Estradiol decreased secretion evoked by pulses of 120 mM K+ for 10 sec to a similar extent in the perfused bovine and cat adrenal gland. The 45Ca++ uptake into bovine chromaffin cells in culture stimulated by DMPP (100 microM for 10 sec) or high K+ (59 mM for 10 sec) was almost inhibited completely by 100 microM 17-alpha-estradiol. The rapid action precludes a classical genomic mechanism and suggests effects at the cell membrane.

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L’objectif de notre étude a été d’évaluer les performances diagnostiques du test Xpert®Bladder Cancer Monitor en comparaison au couple de référence cystoscopie–cytologie pour le suivi de récidives des tumeurs de la vessie n’infiltrant pas le muscle. Ce marqueur a été développé afin de répondre aux inconvénients majeurs de ces 2 examens : invasivité et sensibilité médiocre pour les tumeurs de bas grade.

The role of sodium and calcium ions in the vasconstrictor response of isolated rat aorta and portal vein to synthetically prepared endothelin is investigated. Contractile responses to endothelin, unlike those induced by the sodium channel activator veratridine, are unaffected by tetrodotoxin or by the removal of sodium chloride from the solution bathing the tissue. The responses are the same whether sodium chloride is replaced iso-osmotically with either sucrose or potassium chloride. The endothelin responses in all media are entirely dependent on the presence of extracellular calcium, and can be blocked by 1 μM nitrendipine. These findings offer no support to the idea that voltage activated sodium channels are the primary site of action of endothelin as suggested by sequence homologies to scorpion α-toxins, but are entirely consistent with the possibility that the site of action of endothelin is closely coupled to the calcium channel (Yanagisawaet al, 1988).

The adsorption of polyethylene glycol (MW 20,000) (PEG20000) in the presence of Cl−ions onto a polycrystalline gold electrode was studied using a quartz crystal microbalance, AC voltammetry, and chronocoulometry. This study provided new physical insights into the adsorption behavior of this polymer in the presence of chloride ions on a solid electrode in KClO4. Specifically, three potential-based behaviors were observed: the adsorption of PEG20000was observed to form a condensed phase in the potential range from −0.90 to −0.62 V vs.SCE. The obtained ΔGadsvalues allow for a hypothesis that adsorption occurs by means of hydrogen bridges. In the potential range from −0.62 to −0.10 V vs.SCE, the addition of chloride does not lead to an increased adsorption of PEG20000, but rather to a simple superposition of both adsorption processes. The potential range from −0.10 to 0.35 V vs.SCE is dominated by the adsorption of Cl−ions, and a displacement of adsorbed PEG20000molecules associated with the adsorption of Cl−anions was observed. Based on the obtained ΔGadsvalues, we propose that, in this potential range, the interaction of the PEG20000molecules with the Au polycrystalline electrode surface is defined as weak chemisorption via the oxygen atoms.

The influence of Polyethylene Glycol 200 (PEG200) or a PEG200/benzylideneacetone (BDA) mixture on the mechanism of Zn deposition and nucleation kinetics was studied by voltammetry, chronoamperometry and atomic force microscopy (AFM). The addition of PEG200or PEG200/BDA to the solution partially inhibited the reduction of Zn(II) at E =− 1.135 V vs.SCE. In the presence of PEG200/BDA, an additional reduction process was observed at E =− 1.24 V vs.SCE. Analysis of the nucleation processes indicated that, in all systems studied, the initial stage of Zn deposition was dominated by 3D diffusion-controlled nucleation. At E =− 1.132 V vs.SCE, the addition of PEG200caused a reduction in the nucleation rate constant (A) and the number density of active sites (N0) with respect to the values obtained without additives. AFM analysis of coatings obtained at E =− 1.132 V vs.SCE, showed the formation of Zn clusters with different sizes distributed randomly on the surface. At E =− 1.243 V vs.SCE, both Aand N0were higher for the solution containing the PEG200/BDA mixture than for the systems with PEG200alone or without additives. AFM analysis revealed the formation of similarly sized Zn clusters uniformly distributed on the surface.

In this work, the simultaneous electrodeposition of nickel with zinc was studied in order to determine the influence of the composition of the deposition solution on the properties of the obtained electrodeposits. It was founded that the Ni/Zn concentrations ratio in solution determines the deposition mechanism and thus, the chemical composition and the electrochemical activity of the electrodeposited alloys; in our studied conditions, contrariously to the typical results from these acidic chloride media, Ni-rich alloys (%Ni > 90) were formed by a normal codeposition mechanism with a better electrochemical activity than Ni for the hydrogen evolution reaction HER reaction.

Cyclic voltammetry, differential capacity, and chronocoulometry were employed in a quantitative study of polyethylene glycol (Mw 20000) (PEG20000) adsorption onto a polycrystalline Au substrate. The surface tension, film pressure, relative Gibbs surface excess, and the Gibbs energy of adsorption were determined as a function of the electrode potential. The results indicated that, in the potential interval studied (−0.9 to 0.35 V vs saturated calomel electrode), PEG20000adsorbed onto the polycrystalline Au surface via its oxygen atoms as a flat submonolayer of rodlike molecules. The adsorbed mass increased considerably with the increasing PEG20000concentration and more positive potential. In addition, the surface tension decreased as the quantity of PEG20000adsorbed on the surface rose with the increasing PEG20000concentration, an effect characteristic of surface active agents. The maximum surface concentration was found to be 4.59  ×  10−10moloxygencm−2for the highest PEG20000concentration studied (100 μM). The Gibbs energy of adsorption (ΔGads) was determined using the Henry adsorption isotherm. On the basis of the ΔGadsvalues obtained, it was concluded that the PEG20000molecules were weakly chemisorbed on the polycrystalline Au surface.

Sodium percarbonate (SPC) can be produced electrochemically from aqueous Na2CO3solution in both its 2Na2CO3⋅3H2O2and Na2C2O6forms simultaneously. This was achieved in a two-compartment cell separated by a cation-exchange membrane. Na2C2O6was produced on the anodic side by water oxidation on a boron-doped diamond electrode, with anodic current efficiencies of 20–40%. On the cathodic side, SPC was synthesized from carbonate through generation of H2O2by oxygen reduction on high-surface-area carbon felt. Cathodic current efficiency was 60% and nearly constant. The effect of Na2SiO3as a percarbonate stabilizer was studied during electrolysis and during storage, with 4g∕Lgiving the best performance.

For Abstract see ChemInform Abstract in Full Text.