scholarly journals Trans-Esterification Between Citric Acid and Peanut Oil at Low pH and Ambient Temperature Catalyzed by Citric Acid and Sulfuric Acid Protonic Acid-H<sup>+</sup>

2020 ◽  
Vol 8 (4) ◽  
pp. 100
Author(s):  
Andry Tahina Rabeharitsara ◽  
Jaochim Raherimandimby ◽  
Nambinina Richard Randriana
Keyword(s):  
Sulfuric Acid ◽  
Citric Acid ◽  
Ambient Temperature ◽  
Low Ph ◽  
Peanut Oil ◽  
Protonic Acid

scholarly journals Synthesis of Glues with Citric Acid and Sulfuric Acid Protonic Acid-H<sup>+</sup> as Catalysts Using Banana Peel and Kaki as Valorised Raw Materials

2021 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Andry Tahina Rabeharitsara ◽  
Ratsimba Marie Hanitriniaina ◽  
Rakotomalala Alain Fabrice ◽  
Rakotosaona Rijalalaina ◽  
Nambinina Richard Randriana
Keyword(s):  
Sulfuric Acid ◽  
Citric Acid ◽  
Raw Materials ◽  
Banana Peel ◽  
Protonic Acid

The Bactericidal Effects of an Acidified Sodium Chlorite-Containing Oral Moisturizing Gel: A Pilot Study

2013 ◽  
Vol 39 (6) ◽  
pp. 689-695 ◽  
Author(s):  
Iwao Kuroyama ◽  
Shigeo Osato ◽  
Takahiro Ogawa
Keyword(s):  
Citric Acid ◽  
Pilot Study ◽  
Porphyromonas Gingivalis ◽  
Chlorine Dioxide ◽  
Soft Tissues ◽  
Low Ph ◽  
Sodium Chlorite ◽  
Chemical Dissolution ◽  
Bactericidal Effects ◽  
Chemical Disinfectant

The aim of this study was to examine the bactericidal effects and bactericidal time of an acidified sodium chlorite compound gel (ASC-Gel) on bacteria isolated from the peri-implant sulci of 10 patients who received implants 3–27 years previously, and the depth of each peri-implant sulcus was 5 mm or less. Porphyromonas gingivalis (ATCC33277) was used as the control bacterium. Five ASC-Gel preparations were created by adding 3.3%, 5.0%, 7.0%, 9.0%, and 11.0% citric acid (CA) (condition a, b, c, d, and e, respectively) into an oral moisturizing gel containing sodium chlorite. The concentrations of chlorine dioxide (ClO2) generated in ASC-Gel under conditions (a) to (e) were 12.1, 14.1, 17.2, 21.2, and 39.3 ppm, respectively. We examined the bactericidal effects of the 5 ASC-Gel preparations at volumes of 0.5, 1.0, and 2.0 mL, and measured the bactericidal time when 2.0 mL of ASC-Gel was used under condition (e). The bactericidal effects of ASC-Gel became significantly greater with increased concentrations of CA and ClO2 and with increased usage (0.5−2.0 mL) of the gel. All bacteria were killed by using 2.0 mL of ASC-Gel under condition (e). ASC-Gel also needed between 45 and 90 minutes to kill all microbes under condition (e). Within the limits of the present investigation, these results suggest that ASC-Gel is useful as a chemical disinfectant against bacteria in the peri-implant sulcus. Further studies are also required to protect teeth, the surface of hydroxyapatite-coated implants, and the surrounding soft tissues from effects of chemical dissolution such as acid erosion due to the low pH of ASC-Gel.

Sputter deposition of a corrosion-resistant amorphous metallic coating

1988 ◽  
Vol 3 (5) ◽  
pp. 862-871 ◽  
Author(s):  
Natalia L. Lee ◽  
Galen B. Fisher ◽  
Robert Schulz
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Ambient Temperature ◽  
Sulfuric Acid Solution ◽  
Steel Substrate ◽  
Amorphous Film ◽  
Sputter Deposition ◽  
Low Carbon ◽  
Corrosion Resistant

Starting with corrosion-resistant amorphous Fe32Ni36Cr14P12B6 alloy material, rf sputter deposition has been successfully used to deposit amorphous thin films very similar in composition onto low-carbon (i.e., 1008) steel. The effects that varying sputter deposition parameters has on a film's corrosion resistance, microstructure, and chemical composition have been examined. Optical, scanning, and transmission electron microscopy, Auger depth profiling, and x-ray diffraction were used to characterize the microstructure and composition of the films, while the corrosion resistance was determined by anodic polarization in basic and acidic solutions. A ∼4000 Å thick amorphous film sputtered at ambient temperature onto a 0.05 μm polished 1008 steel substrate improved the corrosion resistance of the steel in a buffered borate solution by lowering the steel's critical current density by two orders of magnitude and by raising its corrosion potential by ∼0.4 V. Bias voltage sputtering was required to produce a film with properties that could withstand a sulfuric acid solution. For example, a film sputtered at – 70 V at ambient temperature onto a steel substrate passivated in sulfuric acid solution, whereas the steel was completely active in this solution without the sputtered film. Passive current densities in this case were ∼2x102μA/cm2. In both solutions the improved corrosion resistance was exhibited by films with lower oxygen content and a denser microstructure. Thus a direct correlation between corrosion resistance, microstructure, and composition is shown.

Study on the Kaolin Fine Tailings Refined Bleached Process

2012 ◽  
Vol 550-553 ◽  
pp. 2917-2920
Author(s):  
Chun Hua Liu ◽  
Zhi Hua Liu ◽  
Chang Bin Xia
Keyword(s):  
Citric Acid ◽  
Oxalic Acid ◽  
Ferric Oxide ◽  
Low Ph ◽  
Aluminum Silicate ◽  
Acid Acid ◽  
Fine Tailings ◽  
The Difference ◽  
Water Cut ◽  
Different Sources

Kaolin is a mineral composition of water cut aluminum silicate collection of words, used widely. But since most kaolin contain quality score 0.5% ~ 3% of iron oxide or hydrogen ferric oxide, restricted its use. With reduction and complexation method to kaolin bleach, which can effectively reduce the content of iron in the clay. The low pH in with organic acid(citric acid, acid, oxalic acid, also sugar) refined bleached high content of coal kaolin ferric oxide. The results show that, citric acid and also the sugar acid in iron effect is poor, does not meet the industrialized production, oxalic acid can remove kaolin can dip in iron, when pH lower than 1.2, the temperature of 80 °C on the bleaching, white degree of more than 80%, to adapt to the industrial application of coal kaolin basic conditions. At the same time, because of the difference of shading minerals, different sources of kaolin bleaching and the white degree stability condition is different, the actual production of should according to the specific of the sources, after the test to be sure.

scholarly journals Combined effects of ocean acidification and elevated temperature on feeding, growth, and physiological processes of Antarctic krill Euphausia superba

2021 ◽  
Vol 665 ◽  
pp. 1-18
Author(s):  
GK Saba ◽  
AB Bockus ◽  
CT Shaw ◽  
BA Seibel
Keyword(s):  
Elevated Temperature ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
Antarctic Krill ◽  
Ph Effect ◽  
Euphausia Superba ◽  
Low Ph ◽  
Interactive Effects ◽  
Growth And Survival ◽  
Key Species

Antarctic krill Euphausia superba is a key species in the Southern Ocean, where its habitat is projected to undergo continued warming and increases in pCO2. Experiments during 2 summer field seasons at Palmer Station, Antarctica, investigated the independent and interactive effects of elevated temperature and pCO2 (decreased pH) on feeding, growth, acid-base physiology, metabolic rate, and survival of adult Antarctic krill. Ingestion and clearance rates of chlorophyll were depressed under low pH (7.7) compared to ambient pH (8.1) after a 48 h acclimation period, but this difference disappeared after a 21 d acclimation. Growth rates were negligible and frequently negative, but were significantly more negative at high (3°C, -0.03 mm d-1) compared to ambient temperature (0°C, -0.01 mm d-1) with no effect of pH. Modest elevations in tissue total CO2 and tissue pH were apparent at low pH but were short-lived. Metabolic rate increased with temperature but was suppressed at low pH in smaller but not larger krill. Although effects of elevated temperature and/or decreased pH were mostly sublethal, mortality was higher at high temperature/low pH (58%) compared to ambient temperature/pH or ambient temperature/low pH (>90%). This study identified 3 dominant patterns: (1) shorter-term effects were primarily pH-dependent; (2) krill compensated for lower pH relatively quickly; and (3) longer-term effects on krill growth and survival were strongly driven by temperature with little to no pH effect.

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