Presence Of Cl Ions Research Articles

The role of different inorganic anions on passive film durability for nickel against chloride ions pitting corrosion in borate buffered solution

Abstract Potentiodynamic and cyclic voltammetric studies were carried out on nickel in borate buffered saline (pH = 8.49). The anodic excursion spans of nickel in borate buffer solution do not involve active/passive transition. The passive film starts to break down in the presence of Cl-ions, which causes pitting damage. The data reveal that the increasing Cl− concentration and solution temperature shifts the E pit to the active direction while the increasing in scan rate shifts the E pit to the positive direction. The pitting potential (E pit) shifted in a positive direction when increasing concentrations of Wo4 −2 and MoO4 −2 anions were added to a borate buffer solution containing Cl− ions, showing that the additional anions had an inhibitory influence on the pitting corrosion. While the NO3 − anion is ineffectual as an inhibitor and rather speeds up pitting corrosion, the NO2 − anion has a slight inhibitory impact on pitting corrosion.

ANALISIS KUALITAS AIR MINUM DALAM KEMASAN (AMDK) DI YOGYAKARTA DITINJAU DARI PARAMETER FISIKA DAN KIMIA AIR

Backgroud: Nowadays, bottled water has become the most substitute water for cooking drinking water. Although bottled water seemed attractive, it is crucial to assess its quality.
 Objective: This quantitative study aimed to determine the quality of the 5 brands of bottled water circulating in Yogyakarta, in terms of physical parameters (temperature, smell, taste, color, turbidity, and TDS electroconductivity) and chemical parameters of water (pH, the presence of Cl-ions, and the presence of metals such as Cr, Fe, Zn, Cd).
 Methods: The sampling technique used was purposive sampling. The instrument used to determine the quality of bottled water is the standard of drinking water quality standards.
 Result: The results showed that five samples of bottled water circulating in Yogyakarta, are all qualified bottled water both in terms of physical parameters (temperature, smell, taste, color, turbidity, electroconductivity, and TDS) and chemical parameters of water (pH , the presence of Cl-ions, and the presence of metals such as Cr, Fe, Zn, Cd).
 Conclusion: Five samples of bottled water circulating in Yogyakarta were suitable for consumption.
 Keywords: Bottled water, water analysis, water quality, water chemistry parameters

Green synthesis and antimicrobial activity of silver chloride nanoparticles stabilized with chitosan oligomer.

Nanocrystalline silver (Ag) and Ag containing nanostructure synthesized using various methods have been studied for their antimicrobial, wound healing, and anti-inflammatory efficacy. Among these, crystalline silver chloride (AgCl) nanostructures exhibit desirable properties for biological and biomedical applications. However, most of them are synthesized using hazardous agents and organic solvents, which has been limited for application in the biological field. A simple and environmentally friendly method was demonstrated for AgCl nanoparticles stabilized with chitosan oligomer (CHI-AgCl NPs) as both a resource of Cl ions and stabilizing agent with expectations of synergistic effects. The CHI-AgCl NPs stabilized by the chitosan oligomer had spherical morphology with a mean diameter of 42±15nm. Ag ions precipitated as AgCl in presence of Cl ions, which remained in the protonated amine group after HCl hydrolysis of the chitosan. Moreover, much of the amine and hydroxyl group bound to the AgCl NPs for growth and stabilization. These nanoparticles were characterized via various spectroscopic techniques, including UV-Vis spectrophotometry, X-ray photoelectron spectrometry, X-ray diffractometry, and transmission electron microscopy.

Water Soluble Polymer-SWCNT-Based Composite for Hydrogen Storage

In this study, water soluble polymers such as poly vinyl alcohol (PVA) and poly vinyl pyrrolidone (PVP) were chosen as the base material for hydrogen storage with the aim of producing recyclable and water-soluble polymer-based hydrogen storage material. Initially, the polymers were acid treated using concentrated hydrochloric acid (conc. HCl) to incorporate Cl ions into the polymeric matrices. Furthermore, single-walled carbon nanotubes (SWCNTs) were added to those acid-treated polymers by means of ultrasonication in an aqueous medium as the composite material to increase the hydrogen adsorption. The homogenous composite solution resulted from ultrasonication was then made in the form of film by using the general spin-coating technique. Then, the composite films were hydrogenated in Seiverts' like hydrogenation setup. The preliminary results on hydrogen storage capability of the polymer-SWCNTs composite materials and desorption temperature range of hydrogen are reported. The prepared composite films exhibit good water-soluble properties and recyclability, i.e., they can be formed and dissolved in water. Hydrogen storage in these acid-treated polymer-SWCNTs composite is reported here for the first time. The presence of Cl ions and the adsorption sites offered by SWCNTs were responsible for hydrogen binding in the composite films. The nature of binding of hydrogen in the composite films was found to be weak chemisorption.

Molecular mechanism of proton transport in CLC Cl-/H+ exchange transporters.

CLC proteins underlie muscle, kidney, bone, and other organ system function by catalyzing the transport of Cl(-) ions across cell and organellar membranes. Some CLC proteins are ion channels while others are pumps that exchange Cl(-) for H(+). The pathway through which Cl(-) ions cross the membrane has been characterized, but the transport of H(+) and the principle by which their movement is coupled to Cl(-) movement is not well understood. Here we show that H(+) transport depends not only on the presence of a specific glutamate residue but also the presence of Cl(-) ions. H(+) transport, however, can be isolated and analyzed in the absence of Cl(-) by mutating the glutamate to alanine and adding carboxylate-containing molecules to solution, consistent with the notion that H(+) transfer is mediated through the entry of a carboxylate group into the anion pathway. Cl(-) ions and carboxylate interact with each other strongly. These data support a mechanism in which the glutamate carboxylate functions as a surrogate Cl(-) ion, but it can accept a H(+) and transfer it between the external solution and the central Cl(-) binding site, coupled to the movement of 2 Cl(-) ions.

Organic phase synthesis of monodisperse iron oxide nanocrystals using iron chloride as precursor

Monodisperse iron oxide nanocrystals were synthesized by a simplified method using iron chloride as precursor. In the presence of Cl ions, the as-produced iron oxide nanocrystals preferred a cubic shape with {100} facets exposed. The function of halogens including Cl and Br ions on stabilizing {100} facets of spinel structured iron oxides, rather than the regulation of thermolysis kinetics and surfactants, was found influential on the shape control of nanocubes in this organic phase approach. The synthesis can be also extended for cobalt ferrite nanocubes and cobalt oxide polyhedrons.

Preparation of Titanium Oxide Photocatalysts Loaded On Activated Carbon and Their Photocatalytic Reactivity for the Degradation of 2-Propanol Diluted in Water

Titanium oxide catalysts loaded on activated carbon (AC) as an adsorbent support were prepared and used as photocatalysts. The photocatalytic reactivity of these catalysts was investigated for the liquid-phase oxidation of 2-propanol diluted in water, and it was found that photocatalysts having the high adsorption ability for activated carbon and the high crystallinity of the anatase TiO 2 phase exhibited efficient photocatalytic reactivity. However, the presence of Cl ions on the activated carbon worked to promote the aggregation of titanium oxide species, and they also promote the formation of a rutile TiO 2 phase which was not preferable for the preparation of efficient TiO 2 /AC photocatalysts.

Stimulation of Elemental Mercury Oxidation in the Presence of Cl Ion in Aquatic Environments (Proceedings of the 21st Symposium on Toxicology and Environmental Health)

Stimulation of Elemental Mercury Oxidation in the Presence of Cl Ion in Aquatic Environments (Proceedings of the 21st Symposium on Toxicology and Environmental Health)

Evidence for protein kinase C as a regulator of intestinal electrolyte transport.

We examined the possibility that the Ca2+-and phospholipid-dependent protein kinase, protein kinase C, may regulate intestinal electrolyte transport. By use of two active phorbol esters, known activators of protein kinase C, we studied the secretory response in rat small intestine. In the in vivo enteropooling assay, 4 beta-phorbol 12-myristate 13-acetate given by gavage produced intestinal fluid secretion and accumulation comparable with that of known secretagogues. The response was dose dependent and only partially blunted at higher doses by atropine. Known inactive phorbol esters failed to elicit a secretory response. In Ussing chamber preparations, 4 beta-phorbol 12,13-dibutyrate applied on the serosal side produced a dose-dependent increase in short-circuit current (Isc). This response was totally dependent on the presence of Cl ion, and as seen in vivo atropine only partially attenuated the Isc response to high concentrations of phorbol ester. Only a minimal increase in Isc was observed when the ester was applied to the mucosal side. Protein kinase C was found to phosphorylate the microvillus membrane of the enterocyte, and the phosphorylation was stimulated by phorbol ester in a concentration-dependent manner. Two membrane proteins of Mr 51,000 and 46,000 were the primary substrates of the enzyme. These studies demonstrate that phorbol esters, specific activators of protein kinase C, elicit the secretory response in rat small intestine both in vivo and in vitro and that this response is mediated by an increase in Cl ion secretion. Furthermore, protein kinase C-mediated phosphorylation of specific microvillus membrane proteins suggests that protein kinase C may modify the functional state of the microvillus membrane of the enterocyte.

Modulation of the GABA receptor complex by a steroid anaesthetic

The interactions of a steroid anaesthetic, alphaxalone, with the GABA receptor-ionophore complex were investigated by two different experimental approaches. In the rat cuneate nucleus slice, alphaxalone (0.1–10 μM) potentiated depolarizing responses to superfused GABA and muscimol, but not those to glycine. The potentiating effect of alphaxalone was unaltered by the benzodiazepine antagonist Ro 15-1788. Alphaxalone (0.1–30 μM) also enhanced [ 3H]muscimol binding to rat brain membranes in the presence of Cl-ions; the enhancing effect on [ 3H]muscimol binding was abolished by Triton X-100. Analysis of binding curves for [ 3H]muscimol indicated that the steroid anaesthetic increases the affinity for [ 3H]muscimol of low affinity binding sites; this property is shared by pentobarbitone. The physiologically inactive ß-hydroxy isomer of the steroid was without activity in either of the experimental situations at 30 μM. It is suggested that alphaxalone and pentobarbitone share a common mode of action on the GABA system, which may be relevant to the mechanisms by which these drugs produce anaesthesia.

The electrophysiological basis of the motor inhibitory effect of adrenaline on rabbit small intestinal smooth muscle

The spontaneous electrical activity of small intestinal smooth muscle cells consists of repetive depolarizations (control activity) on which spikes (response activity) may be superimposed; each spike is preceded by a prepotential. Response activity is associated with contractions. Adrenaline initially abolished the response activity and any prepotenials, as well as the contractions, without altering the control activity or the membrane potential. This effect was followed by hyperpolarization and slight increase in the control potential amplitude. The hyperpolarization was insenstitive tto temperature (Q10 = 1.01) and was larger when the membrane was initially depolarized by K withdrawal but did not occur after the membrane was hyperpolarized by replacing C1 by propionate or by prolonged K withdrawal. It is suggested that adrenaline inhibits intestinal motility by uncoupling the control activity to response activity through suppression of the prepotentials. The adrenaline-induced hyperpolarization may be due to an increase in K permeability but not to stimulation of electrogenic Na pumping. The increase in K permeability may depend upon the presence of Cl ions.

Carbonic anhydrase activity of mucosa of small intestine and colon.

THERE is evidence that in the small intestine and colon of mammals the transport of Cl ions and of HCO3 is, to a certain extent, interdependent. Thus the movement of bicarbonate ions across the small intestine shows some dependence on the presence of Cl ions in the lumen, and it has been suggested that some Cl ions are absorbed in exchange for bicarbonate ions secreted into the lumen of the small intestine and colon1–4. Because a relationship may exist therefore between CO2 metabolism and ion transport in the intestine, the question of the presence of the enzyme carbonic arihydrase (E.G.4.2.1.1) in the intestinal tract is important.

Zur Bildung von Anionenlücken in fremdionen‐dotierten KBr‐Kristallen durch Röntgenbestrahlungen

AbstractDie vorliegende Arbeit behandelt die Rolle von Fremdionen bei der Erzeugung von Anionenlücken durch Röntgenbestrahlung bei niedrigen Temperaturen. Im ersten Teil der Arbeit werden die Erzeugung und die thermische Stabilität von Anionenlücken in röntgenbestrahlten KBr‐Kristallen mit photochemischen Prozessen in Kristallen verglichen, die Hydrid‐Ionen enthalten. Es wird angenommen, daß die Anionen bei der Röntgenbestrahlung infolge eines der U ‐ α‐Umwandlung analogen Prozesses ihre Gitterplätze verlassen. Um diese Vorstellung zu prüfen, wird im zweiten Teil der Arbeit die Erzeugung von α‐ und F‐Zentren in KCl‐dotierten KBr‐Kristallen bei 90° K untersucht. Die Anfangsrate der Bildung von α‐Zentren hängt in charakteristischer Weise vom Verhältnis der Halogenid‐Komponenten in den Mischkristallen ab. Im Gegensatz hierzu wird die Erzeugungsrate von F‐Zentren durch die Anwesenheit von Cl‐Ionen nicht wesentlich beeinflußt. Dieser Effekt wird auf der Grundlage der vorangegangenen Betrachtung gedeutet. Einige Beobachtungen über die Lage der Maxima von α‐ und β‐Banden in Mischkristallen werden im Anhang mitgeteilt.