scholarly journals Na2S-influenced electrochemical migration of tin in a thin electrolyte layer containing chloride ions

RSC Advances ◽  
2017 ◽  
Vol 7 (25) ◽  
pp. 15060-15070 ◽  
Author(s):  
Bokai Liao ◽  
Lisha Wei ◽  
Zhenyu Chen ◽  
Xingpeng Guo
Keyword(s):  
Chloride Ions ◽  
Electrochemical Migration ◽  
Schematic Diagram ◽  
High Concentration ◽  
Electrolyte Layer ◽  
Low Concentration ◽  
Thin Electrolyte Layer

A schematic diagram of the effect of Na2S concentration on the ECM behavior of tin, from low concentration to high concentration.

Effect of citrate ions on the electrochemical migration of tin in thin electrolyte layer containing chloride ions

2016 ◽  
Vol 112 ◽  
pp. 393-401 ◽  
Author(s):  
Bokai Liao ◽  
Zhenyu Chen ◽  
Yubing Qiu ◽  
Guoan Zhang ◽  
Xingpeng Guo
Keyword(s):  
Chloride Ions ◽  
Electrochemical Migration ◽  
Electrolyte Layer ◽  
Thin Electrolyte Layer ◽  
Citrate Ions

Electrochemical migration of tin in thin electrolyte layer containing chloride ions

2013 ◽  
Vol 74 ◽  
pp. 71-82 ◽  
Author(s):  
Xiankang Zhong ◽  
Guoan Zhang ◽  
Yubing Qiu ◽  
Zhenyu Chen ◽  
Xingpeng Guo
Keyword(s):  
Chloride Ions ◽  
Electrochemical Migration ◽  
Electrolyte Layer ◽  
Thin Electrolyte Layer

Effect of Organic Acids on the Electrochemical Migration of Tin in Thin Electrolyte Layer

2019 ◽  
Vol 9 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Bokai Liao ◽  
Hongyu Cen ◽  
Zhenyu Chen ◽  
Xingpeng Guo
Keyword(s):  
Organic Acids ◽  
Organic Acid ◽  
Optical Observations ◽  
Ex Situ ◽  
Anode Surface ◽  
Electrochemical Migration ◽  
Electrolyte Layer ◽  
Weak Organic Acids ◽  
Weak Organic Acid ◽  
Thin Electrolyte Layer

Background and Objective: The effects of representative solder flux residue weak organic acids on electrochemical migration (ECM) of tin in thin electrolyte layer were studied using a technique based on the coupling of in situ electrochemical measurements and optical observations, as well as ex situ characterizations. Methods and Results: The results showed that the increasing amount of weak organic acid decreased the probability of ECM and dendrites formed were mainly composed of metallic tin. Tin ions reacted with organic compound ions from hydrolysis of weak organic acids to form complexes with electronegativity, which retarded the transfer of tin ions. Some complexes can be oxidized to the insoluble tin oxides on the anode surface and blocked the dissolution of anode during tin ECM. Conclusion: The growth rate of tin dendrite was found to be limited by the dissociation of complexes. Mechanisms involved were proposed to explain the role of weak organic acid in the tin ECM.

Study on Switch from High-concentration to Low-concentration Tacalcitol during Concomitant Use of Bath-PUVA Therapy

2007 ◽  
Vol 69 (6) ◽  
pp. 660-664
Author(s):  
Maki IWAKIRI ◽  
Noriko YASAKA ◽  
Kotaro ITO ◽  
Yuichi YOSHIDA ◽  
Yumiko KUBOTA ◽  
...  
Keyword(s):  
Puva Therapy ◽  
High Concentration ◽  
Low Concentration

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

Molecular Characterization of the Surface Excess Charge Layer in Droplets

2020 ◽  
Author(s):  
Victor Kwan ◽  
Styliani Consta
Keyword(s):  
Hydrogen Bonds ◽  
Surface Charge ◽  
Droplet Size ◽  
Chloride Ions ◽  
Total Charge ◽  
Excess Charge ◽  
Surface Excess ◽  
High Concentration ◽  
Dipole Orientation ◽  
Charge Layer

<div>Charged droplets play a central role in native mass spectrometry, atmospheric aerosols and in serving as micro-reactors for accelerating chemical reactions. The surface excess charge layer in droplets has often been associated with distinct chemistry. Using molecular simulations for droplets with Na+ and Cl- ions we have found that this layer is ≈ 1.5−1.7 nm thick and depending on the droplet size it includes 33%-55% of the total number of ions. Here, we examine the effect of droplet size and nature of ions in the structure of the surface excess charge layer by using molecular dynamics. We find that in the presence of simple ions the thickness of the surface excess charge layer is invariant not only with respect to droplet size but also with respect to the nature of the simple ions and it is not sensitive to fine details of different force fields used in our simulations.</div><div> In the presence of macroions the excess surface charge layer may extend to 2.0. nm. For the same droplet size, iodide and model hydronium ions show considerably higher concentration than the sodium and chloride ions. <br></div><div>We also find that differences in the average water dipole orientation in the presence of cations and anions in this layer are reflected in the charge distributions. Within the surface charge layer, the number of hydrogen bonds reduces gradually relative to the droplet interior where the number of hydrogen bonds is on the average 2.9 for droplets of diameter < 4 nm and 3.5 for larger droplets. The decrease in the number of hydrogen bonds from the interior to the surface is less pronounced in larger droplets. In droplets with diameter < 4 nm and high concentration of ions the charge of the ions is not compensated only by the solvent polarization charge but by the total charge that also includes the other free charge. This finding shows exceptions to the commonly made assumption that the solvent compensates the charge of the ions in solvents with very high dielectric constant. The study provides molecular insight into the bi-layer droplet structure assumed in the equilibrium partitioning model of C. Enke and assesses critical assumptions of the Iribarne-Thomson model for the ion-evaporation mechanism. <br></div>

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura &amp; Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

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