scholarly journals Electrochemically Fabricated Surface-Mesostructured CuNi Bimetallic Catalysts for Hydrogen Production in Alkaline Media

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 118
Author(s):  
Jingyuan Bai ◽  
Jin Zhang ◽  
Konrad Eiler ◽  
Zhou Yang ◽  
Longyi Fan ◽  
...  

Ni-based bimetallic films with 20 at.% and 45 at.% Cu and mesostructured surfaces were prepared by electrodeposition from an aqueous solution containing micelles of P123 triblock copolymer serving as a structure-directing agent. The pH value of the electrolytic solution had a key effect on both the resulting Cu/Ni ratio and the surface topology. The catalytic activity of the CuNi films toward hydrogen evolution reaction was investigated by cyclic voltammetry (CV) in 1 M KOH electrolyte at room temperature. The Cu45Ni55 film showed the highest activity (even higher than that of a non-mesostructured pure Ni film), which was attributed to the Ni content at the utmost surface, as demonstrated by CV studies, as well as the presence of a highly corrugated surface.

Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.


1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).


2021 ◽  
Vol 98 ◽  
pp. 14-18
Author(s):  
Thao Nguyen Thi ◽  
◽  
Nam Pham Ky ◽  
Ngoc Tran Vu Diem

Brass melting slag (20.38 wt.% Zn) was leached in sulfuric acid with concentration of (50 + 80) g/l H2SO4, leaching temperature of (30 + 60) °C for (30 + 120) min. The optimized conditions for 94.16% Zn extraction from brass melting slag were found as 70 g/l H2SO4, room temperature and 90 min. The leaching solution was purified by removal of Fe through Fe(OH)3 precipitation when adding ZnO to adjust pH value of 5. The solution was continuously cemented by Zn metal at 60 °C for 60 min to obtain Cu metal with high purity of 99 wt.% Cu. The purified solution with 37.64 g/l Zn was modified by Na2C03 to have pH value of about 6 and precipitation of ZnC03 (94.14 %).


2018 ◽  
Vol 91 (9) ◽  
pp. 1441-1450 ◽  
Author(s):  
I. V. Makarova ◽  
D. S. Kharitonov ◽  
I. B. Dobryden’ ◽  
A. A. Chernik

2017 ◽  
Vol 21 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Yunfeng Hu ◽  
Zengyu Wei ◽  
Yuanyuan Chen

AbstractIn this paper, the quality changes of fresh dumpling wrappers during storage were studied by measuring the changes of microbial growth, color, pH, texture, cooking property, moisture content and distribution of raw dumpling wrappers. The correlation of these indicators was analyzed. The results showed that the dumpling wrappers had generated lots of microorganisms during storage and the pH value decreased gradually. The dumpling wrappers had browning and the color became darker. The texture of the dumpling wrappers changed obviously. The original structure of raw dumpling wrappers were destroyed, the water distribution is uneven and migration to the surface. The apparent index of raw dumpling wrappers has a significant correlation with the internal change, which provides a certain guiding significance for maintaining the good quality of dumpling wrappers.


2020 ◽  
Vol 10 (03) ◽  
pp. 374-377
Author(s):  
Ibtihal Ismail Muhammad Al-Ani

The present study aimed to study the possibility of producing a drink that looks like grafted milk by using chickpeas and evaluate its physical, chemical, microbial, and sensory properties. The result showed the superiority of F treatment (soaking 100 grams of chickpeas at the refrigerator temperature 4ºC for 12 hours) over the rest seven treatments in extraction efficiency, which was 70%, while, it was 50.5% in H treatment (soaking 100 grams of chickpeas in the heated water at 60ºC for 30 minutes). The highest value of the product density was after water and flavorings addition in the D treatment (soaking 100 grams chickpeas in 0.05 soda solution at 60ºC for 30 minutes), and it was 0.97 g cm-3, compared with the lowest density 0.57 g cm-3 in A treatment (soaking 100 grams chickpeas in 0.05 soda solution at room temperature 25ºC for 12 hours). pH values were highest in A treatment compared with the other treatments, and its value was 7.66 in the 1st and 2nd day, after dissolving in a refrigerator at 4ºC, and then, for 5 minutes at room temperature 30ºC. The lowest value in the D treatment was 6.45 on the 1st day, and 6.87 on the 2nd day in the G treatment. On the 3rd day, the highest pH value was 7.13 in the D treatment, and the lowest value 6.79 was in the E treatment. pH highest value was 6.2 on the 4th day in A treatment. From the last results, it may be concluded that F treatment was the best in extraction efficiency, the final product density, and less total bacterial number, after dissolving for 5 days at refrigerator temperature 4ºC, and then, at room temperature 30ºC for 3 and 48 hours incubation. The best extraction volume and pH were in A treatment.


2020 ◽  
Vol 25 (1) ◽  
pp. 52
Author(s):  
Alston Millan

Nutmeg oleoresin microcapsule is the solid, liquid, and gas coating technology of the nutmeg fruit.  The purpose of this study was to know how mace nutmeg oleoresin microcapsules could preserve the broiler chicken meat at room temperature during 4 days of observation. The experimental design used was a Completely Randomized Design (CRD) consisting of 5 treatments with mace concentration of nutmeg microcapsules oleoresin (0, 50, 100, 150, and 200) ppm. The variables observed were water content, pH value, total microbes, and organoleptic properties (color, aroma, and texture). The results showed that mace nutmeg oleoresin microcapsules did not affect (p> 0.05)  water content and sensory properties of broiler chicken meat, but had a significant effect (p <0.05) on the pH value and total microbe at the same day of room temperature storage. Panel organoleptic test results on the level of preference for meat color, aroma, and texture of chicken meat were in the range score of 3 (somewhat like) to 4 (somewhat dislike). The treatments of nutmeg oleoresin did not affect (p> 0.05) on color, the aroma, and the texture of broiler chicken meat. This research shows that marinating using oleoresin microcapsules has not been effective as a preservative to broiler chicken meat at room temperature. Keywords: chicken meat, mace nutmeg oleoresin microcapsules


2013 ◽  
Vol 832 ◽  
pp. 767-772 ◽  
Author(s):  
Shoichiro Ikeda ◽  
Shinji Kawasaki ◽  
Akinari Nobumoto ◽  
Hideo Ono ◽  
Shinji Ono ◽  
...  

We have produced nanocarbon suspension in pure water, which is named as Nanocaloid®, by a simple DC electrolysis from a synthetic graphite plates as anodes and SUS plates as cathodes in purified water at room temperature. The amount of carbon nanoparticles was monitored by the conductivity and pH value of the electrolyte solution, and also by a simple gravimetric way after drying the solution. If the current density increases, the diameter of the carbon particles becomes larger and the amount of precipitates becomes also large. It takes about six weeks to obtain about 0.4 wt% carbon suspension solution under the normal electrolysis conditions. Characterization of Nanocaloid®has been conducted to show unique properties and promising epoch-making applications such as solid lubricants for non-oily cutting fluids and conductive agents for reuse of deteriorated Pb-acid batteries. The performance of nanocarbon particles in oil lubricants in addition to the preparation will be reported.


2020 ◽  
Vol 859 ◽  
pp. 57-61
Author(s):  
Suwannee Panomsuk ◽  
Kunyakorn Keawsri ◽  
Chanapa Limsatjapanit ◽  
Nutcha Asaneesantiwong ◽  
Parichat Chomto ◽  
...  

Clove oil is the volatile essential oil obtained from Syzygium aromaticum. Eugenol, which is the main component, has antimicrobial, antifungal activity and antioxidant. From antiseptic activity, clove oil can be used in treatment of oral cavity infection. The aims of this research are to formulate and evaluate clove oil mucoadhesive gel for oral applications. Gel bases were prepared from Poloxamer 407 (P407). The effect of clove oil, P407 and xanthan gum on formulations were studied. Clove oil preparations were evaluated for their physicochemical properties (physical appearance, pH, viscosity, gelling capacity and gel dissolving time at 37 °C in artificial saliva). Mucoadhesive property was studied using porcine buccal mucosa. The amount of eugenol in clove oil was analyzed by gas chromatography (GC). Stability study of clove oil gel was performed under stress and room temperature conditions (1 month). The results showed that preparations containing 0% and 1% clove oil were in situ gel while those containing 3% and 5% clove oil were gel. All formulations showed good and clear physical appearance with the pH value of 5.2. The gelling capacity and gel dissolving time of more than 15 minutes in artificial saliva at 37°C was found in all preparations. They also showed mucoadhesive property. The GC results showed that the amount of eugenol in clove oil were 99.52 ± 0.51 %V/V. The preparations containing 1% clove oil showed good physical and chemical stability after storage at room temperature for 1 month. There was no significant difference in the amount of eugenol after storage (p>0.05). In conclusion, the preparations containing 20% P407 and 1% clove oil are the most appropriate formulation.


Sign in / Sign up

Export Citation Format

Share Document