scholarly journals Inside Cover: Correlation between CO Oxidation and H Adsorption/Desorption on Pt Surfaces in a Wide pH Range: The Role of Alkali Cations (ChemElectroChem 3/2017)

2017 ◽  
Vol 4 (3) ◽  
pp. 457-457
Author(s):  
Gonzalo García
Keyword(s):  
Co Oxidation ◽  
Alkali Cations ◽  
Wide Ph Range ◽  
Ph Range ◽  
Adsorption Desorption

Dynamic Light Scattering and Zeta Potential Studies of Ceria Nanoparticles

2018 ◽  
Vol 278 ◽  
pp. 112-120 ◽  
Author(s):  
Ishaq Yusuf Habib ◽  
N.T.R.N. Kumara ◽  
Chee Ming Lim ◽  
Abdul Hanif Mahadi
Keyword(s):  
Average Particle Size ◽  
Nanoparticle Synthesis ◽  
Average Particle ◽  
Wide Range ◽  
Isoelectric Points ◽  
Wide Ph Range ◽  
Electrolyte Mixture ◽  
Oxide Nanoparticle ◽  
Ph Range ◽  
Adsorption Desorption

A Cerium (IV) oxide nanoparticle (nanoceria) is widely used in different applications such as biomedicine and catalysis due to its unique structural, morphological and catalytic properties. In this report, the dispersion of nanoceria in both aqueous and non-aqueous (methanol and ethanol) media were studied. Adsorption-desorption processes were observed upon addition of different classes of surfactants such as citric acid (CA), cetrimonium bromide (CTAB) and diethanolamine (DEA). Stable dispersions were obtained in both aqueous, non-aqueous and electrolyte assisted media with the overall mechanism being hydrolysis, dissolution and adsorption. XRD, FE-SEM, FTIR and DLS have been used in the present study to characterize the nanoceria and to quantitatively analyze their average particle size distributions in a unique electrolyte mixture of (0.1 M NaOH/ 65% HNO3:H2O, 1:1 v/v) which has not been reported previously. The surface charge study was carried out across a wide pH range between 1.4 – 9.6 and the isoelectric points (IEP) with respect to 15 ml H2O and 50 ml H2O dispersed phases occurred at a pH of about 6.5 and 6.7 respectively. The present study could be useful in a wide range of applications including nanoparticle synthesis, stabilization, and adsorption of toxic materials, biomedical and pharmaceutical.

Role of Persistent Vascular Renin after Bilateral Nephrectomy in Goldblatt-Two Kidney Hypertension

1978 ◽  
Vol 55 (s4) ◽  
pp. 23s-26s ◽  
Author(s):  
H. Thurston ◽  
B. C. Hurst ◽  
R. F. Bing ◽  
J. D. Swales
Keyword(s):  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Bilateral Nephrectomy ◽  
Salt Loading ◽  
Angiotensin System ◽  
Wide Ph Range ◽  
Salt Depletion ◽  
Ph Range ◽  
Aortic Homogenate

1. Aortic homogenate contains renin-like activity which on incubation generates angiotensin I over a wide pH range. 2. Rat aortic renin measured at an incubation pH of 6·5 rose and fell in parallel to plasma renin with salt depletion and salt-loading respectively. Renin measured at an incubation pH of 5·3 showed little relationship with plasma renin. 3. Aortic renin (pH 6·5) was elevated in Goldblatt-two kidney hypertension and slowly fell for 24 h after bilateral nephrectomy whereas the fall in plasma renin was complete by the first hour. Aortic renin (pH 5·3) was also high, but did not fall after bilateral nephrectomy. 4. Aortic renin (pH 6·5) is probably derived from plasma renin whereas renin measured at pH 5·3 is probably a tissue renin. 5. The prolonged half-life of aortic renin (pH 6·5) explains the observation that the renin—angiotensin system appears to be active in maintaining blood pressure for several hours after bilateral nephrectomy whereas the decline in plasma renin is rapid and does not continue significantly beyond 1 h.

A structural perspective on lactoferrin function1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal's usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Heather M. Baker ◽  
Edward N. Baker
Keyword(s):  
Peer Review Process ◽  
Iron Binding ◽  
Multifunctional Protein ◽  
Wide Ph Range ◽  
Iron Binding Protein ◽  
Productive Research ◽  
Ph Range ◽  
The Many ◽  
And Function

The 3-D structure of human lactoferrin was first solved in atomic detail in 1987. Since that time, a variety of proven and postulated activities have been added to the original annotation of lactoferrin as an iron-binding protein. Structural studies have also expanded to include iron-bound and iron-free (apo) forms, mutants, and the lactoferrins of different species. In this review, we take the current information on both structure and function and show that the 3-D structure provides a useful framework for understanding some activities and also points to productive research directions that could help elucidate other reported functions. Some functions relate to iron binding where the role of lactoferrin is to scavenge and retain iron across a wide pH range. We specifically focus on functions that depend on the surface structure of the molecule, identifying features that may determine the many other protective properties of this multifunctional protein.

The role of zirconia in cobaltosic oxide catalysts for low-temperature CO oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 111070-111078 ◽  
Author(s):  
Fan Du ◽  
Guisheng Wu ◽  
Dongsen Mao ◽  
Guanzhong Lu
Keyword(s):  
Low Temperature ◽  
Co Oxidation ◽  
Co Adsorption ◽  
Oxide Catalysts ◽  
Low Temperature Co Oxidation ◽  
Cobaltosic Oxide ◽  
Adsorption Desorption

A series of Co3O4/ZrO2 catalysts for low-temperature CO oxidation was prepared, and then characterized by low-temperature N2 adsorption/desorption, XRD, TEM, XPS, UV-vis, CO-TPR, CO adsorption and CO2 desorption.

Some Observations on the Saponin Accumulation in Oat Seedlings and on the Transformation of the Avenacosides to the Antibiotic 26-Desgluco-avenacosides

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1095-1099 ◽  
Author(s):  
Ute Laudenbach ◽  
Jürgen Kesselmeier
Keyword(s):  
Protective Device ◽  
Steroidal Saponins ◽  
Temperature Optimum ◽  
Plastid Development ◽  
Drastic Decrease ◽  
Etiolated Seedlings ◽  
Wide Ph Range ◽  
Ph Range ◽  
Distinct Temperature

Abstract The accumulation of the steroidal saponins avenacoside A and B in oat was investigated in green and etiolated seedlings and was found to be strictly bound to the growth of the seedlings. No significant differences were detected between green and etiolated seedlings, showing that there is no relation between saponin accumulation and plastid development. As the role of the oat saponins has to be seen as a protective device against fungi and bacteria, the transformation of the inactive avenacosides to their corresponding antibiotic 26-desgluco-avenacosides was tested in dependence of pH and temperature. During disruption of leaves, transformation occurs almost completely over a wide pH-range (pH 4 -pH 10); the degree of transformation exhibits no distinct temperature optimum but a drastic decrease at 70 °C.

RECOVERY OF GERMANIUM BY PRECIPITATION FROM STRONGLY ALKALINE SOLUTION

2020 ◽  
Author(s):  
Andrzej Piotrowicz ◽  
Stanisław Pietrzyk ◽  
Artur Puchała
Keyword(s):  
Alkaline Solution ◽  
Precipitation Process ◽  
Research Material ◽  
Low Concentrations ◽  
Industrial Material ◽  
Industrial Solution ◽  
Wide Ph Range ◽  
Synthetic Solution ◽  
Ph Range

The research material was a strongly alkaline solution containing germanium, lead, arsenic, zinc and trace amounts of other metals, obtained by leaching of industrial material. The aim of the study was to determine the behavior of the above metals in the precipitation process using various acidic agents: HCl, H2SO4, C2H2O4, C6H8O7. The tests were carried out in a wide pH range. The behavior and role of individual ions during the acidification of germanate solution is poorly understood, hence the study of this subject was undertaken. The resulting precipitates and solutions were examined by XRF, XRD and ICP techniques. The recovery yields of individual elements was determined. Attempts were also made to precipitate Ge from a synthetic solution in order to compare the results obtained for the solution of an industrial solution. This research shows that the presence of other ions interferes with the selective recovery of Ge from research solutions. Generally, it can be said that the method of recovery by acidification is effective at low concentrations of the solution's components.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

High degradation efficiency of sulfamethazine with the dual-reaction-center Fe-Mn-SiO2 Fenton-like nanocatalyst in a wide pH range

2021 ◽  
Author(s):  
Manoj Kumar Panjwani ◽  
Qing Wang ◽  
Yueming Ma ◽  
Yuxuan Lin ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Center ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Wide Ph Range ◽  
Ph Range

The development of a heterogeneous Fenton-like catalyst, possessing high degradation efficiency in a wide pH range, is crucial for wastewater treatment. The Fe-Mn-SiO2 catalyst was designed, and prepared by a...

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